Epitope recognized by anti-interferon gamma autoantibodies in patients with disseminated mycobacterial infections and the application therefor

Abstract

The present invention discloses a fragment of peptide which can be utilized in patients suffering from a disseminated mycobacterial infection. The fragment of peptide contains a sequence of amino acids with seven residues as formula (I) shown below, wherein X1 is Leucine (Leu); X2 is Proline (Pro); X3 is Glutamate (Glu); X4 is serine (Ser); X5 is Serine (Ser); X6 is Leucine (Leu) and X7 is Arginine (Arg): X1-X2-X3-X4-X5-X6-X7 (I).

Description

CROSS-REFERENCE TO RELATED APPLICATION AND CLAIM OF PRIORITY

The application claims the benefit of Taiwan Application No. 104119897, filed on Jun. 22, 2015, at the Taiwan Intellectual Property Office, the disclosures of which are incorporated herein in their entirety by reference.

FIELD OF THE INVENTION

The invention is related to a medical, dental or toilet preparation. In particular, it is related to the preparation of one kind of peptide fragments, which can be used in patients suffering from a disseminated mycobacterial infection.

BACKGROUND OF THE INVENTION

Anticytokine autoantibodies (ACADs) are increasingly recognized, and playing an important role in the pathogenesis of infectious and autoimmune diseases.

Clinically, the pathogenic mycobacterial species can cause tuberculosis, Hansen's disease, leprosy, pulmonary disease, lymphadenitis and skin disease. In view of mycobacterial immunity, IFN_r plays an important role and is mainly produced by T and NK cells when stimulated with microbial products.

Genetic defects in the IFN_r/IL-12 pathway cause Mendelian susceptibility to mycobacterial diseases (MSMDs) in young patients with disseminated mycobacterial infections.

On the other hand, interference with the IFN_r signaling by the presence of anti-IFN_r AutoAbs is the major etiology that explains the occurrence of severe disseminated mycobacterial infections in adults without obvious immunologic defects, in particular for patients from the Southeast Asia.

The similarity of clinical susceptibility to MSMDs strongly suggests that AutoAbs against IFN_r were the cause rather than a consequence of mycobacterial infection.

The mechanism of the production of anti-IFN_r AutoAbs also remains unclear. Restriction of the disease in Southeast Asian population suggest that a particular genetic factor and mechanism are involved.

According to a previous study, HLA class II molecules DRB1*16:02 and HLA-DQB1*05:02 are the two specific alleles strongly associated with this disease, and the high frequency of this allele in Southeast Asia might also explain the susceptibility of anti-IFN_r AutoAbs in this particular population.

MHC class II is present the particular peptides to CD4⁺ T cells to induce an adaptive immune response and is a strong genetic factor associated with autoimmune diseases. It seems that particular pathogenic peptide fragments present in these particular HLA alleles are involved in the production of anti-IFN_r AutoAbs.

Various hypotheses have been proposed to explain the production of these pathogenic AutoAbs. Molecular mimicry theory states that exo-antigen can mimic self-antigen and induces the formation of AutoAbs. This theory, molecular mimicry, has been documented in various autoimmune diseases, including multiple sclerosis (MS), ankylosing spondylitis, Graves' disease, diabetes mellitus, and systemic lupus erythematosus (SLE).

In the case of MS and SLE, the disease pathogenesis has been linked to some viruses, such as the Epstein-Barr virus (EBV), for their homologous amino acid sequences with human antigenic structures in the central nerve system or lupus autoantigens, such as Sm B.

These findings suggest that molecular mimicry plays a major role in the pathogenesis of certain diseases. Despite advances in the genomic technologies for autoimmunity, the precise mechanism for the pathogenic AutoAbs formation is still unclear.

SUMMARY OF THE INVENTION

Autoantibodies (AutoAbs) against IFN_r is an emerging medical issue and linked to disseminated mycobacterial infections and other opportunistic infections in the Southeast Asia. The origin of these AutoAbs is unclear; however, the majority of affected patients share specific HLA class II alleles and this observation suggests that a common mechanism in the production of AutoAbs may exist. Herein, the inventor characterized the anti-IFN_r AutoAbs from patients and found these AutoAbs recognized a major epitope (P_121-131) in the C-terminal of IFN_r. The region was known to be critical for IFN_r receptor activation, and the inventor also demonstrated that AutoAbs to this epitope had a neutralizing activity. This epitope was 100% homologous to the Aspergillus Noc2 and anti-IFN_r AutoAbs from patients could react with this epitope and Aspergillus Noc2. In vivo study, rats immunized with Aspergillus Noc2 developed antibodies against human IFN_r and vice versa.

In addition, the inventor generated an epitope Erase IFN_r (EE-IFN_r) which has lower affinity recognized by anti-IFN_r AutoAbs due to a modified major epitope region and it could activate the IFN_r downstream signaling pathway ex vivo even in the presence of anti-IFN_r AutoAbs.

It was found that anti-IFN_r ⋅AutoAbs from different patients recognized a specific region, SPAAKTGKRK (SEQ ID NO: 14), in the C-terminal of IFN_r and these antibodies had a neutralizing activity on IFN_r.

A high homologous peptide sequence in this region (KTGKRKR (SEQ ID NO: 36)) was found in Aspergillus Noc2 and also recognized by the anti-IFN_r AutoAbs.

After immunization with Aspergillus Noc2, antibodies against human IFN_r ⋅ were formed in the test rats.

Furthermore, the inventor used a mouse homologous region to replace the critical anti-IFN_r ⋅AutoAb-recognized epitope in human IFN_r□ and generated a new recombinant protein, epitope Erased IFN_r ⋅(EE-IFN_r).

This recombinant protein could induce the activation of the IFN_r receptor, even in the presence of anti-IFN_r ⋅AutoAbs ex vivo.

Taken together, the results suggest that anti-IFN_r ⋅AutoAbs may be induced by the means of molecular mimicry, and structural modification of IFN_r ⋅ can bypass the blocking activity of anti-IFN_r ⋅AutoAbs.

In accordance with one aspect of the present invention, a method for evaluating an efficacy of an isolated recombinant human interferon gamma (hIFN_r) for regulating a peripheral blood mononuclear cell (PBMC) is disclosed. The method comprises the steps of: providing the PBMC from a subject with anti-interferon gamma autoantibodies; mixing the isolated recombinant human interferon gamma with the PBMC, wherein the isolated recombinant human interferon gamma contains a homologous substitute; and evaluating the efficacy of the isolated recombinant human interferon gamma according to an expression level of a phosphorylation of signal transducers and activators of transcription 1 (p-STAT1) generated by the PBMC.

In accordance with another aspect of the present invention, a method for evaluating an efficacy of an isolated recombinant cytokine for regulating a peripheral blood mononuclear cell (PBMC) is disclosed. The method comprises steps of: providing the PBMC from a subject with an anticytokine autoantibody; mixing the isolated recombinant cytokine with the PBMC, wherein the isolated recombinant cytokine contains a homologous substitute; and evaluating the efficacy of the isolated recombinant cytokine according to an expression level of an interleukin-12 (IL-12) generated by the PBMC.

In accordance with another aspect of the present invention, a recombinant protein is disclosed. The recombinant protein comprises: a human interferon gamma having a sequence replaced with a peptide of “Leu-Pro-Glu-Ser-Ser-Leu-Arg” (SEQ NO: 1), wherein the recombinant protein is used to activate a receptor of an interferon gamma (IFN_r) and is free from neutralization by an autoantibody of the interferon gamma of a subject suffering from a disseminated mycobacterial infection.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1a-1h illustrate AutoAbs to IFN_r recognized C-terminal region of IFN_r according to the embodiment of the present invention;

FIGS. 2a-2e illustrate epitope Erase IFN_r according to the embodiment of the present invention;

FIGS. 3a-3g demonstrate molecular mimicry;

FIGS. 4a-4h illustrate epitope Erase IFN_r and the application therefor according to the embodiment of the present invention;

FIG. 5 illustrates IFN_r direct ELIAS used to detect AutoAbs against IFN_r;

FIGS. 6a-6b illustrate that IL-12 production levels and IFN_r production levels were measured by ELISA;

FIG. 7 illustrates the result of epitope mapping;

FIG. 8 illustrates the result of Western blot analysis conducted on various recombinant interferons;

FIG. 9 illustrates the results of probing plasma sampled from IFN_r AutoAbs patients and healthy controls;

FIG. 10 illustrates the results of protein mapping;

FIGS. 11a-11b illustrate the results of plasma interacting with hIFN_r and mIFN_r;

FIG. 12 illustrates the results of Western blot analysis conducted on different various recombinant Noc2 proteins; and

FIGS. 13a-13b illustrate the results of p-STAT-1 expression levels and HLA-DR expression levels.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of preferred embodiments of this invention are presented herein for the purposes of illustration and description only; they are not intended to be exhaustive or to be limited to the precise form disclosed.

[Patients and Definitions]

All participants were adults (age >20 years) and were followed regularly at medical centers in Taiwan. Disseminated mycobacterial infection was diagnosed if patients presented 2 or more noncontiguous places and positive blood or BM cultures. The diagnosis of pulmonary NTM infection was based on the criteria proposed by the American Thoracic Society and Infectious Diseases Society of America. The study was approved by the Institutional Review Board of China Medical University Hospital (DMR98-IRB-261) and Chang Gung Memorial Hospital (103-2861C), and informed written consent was obtained from all of the patients in accordance with the Declaration of Helsinki.

[Reagents]

The inventor used the following monoclonal antibodies: anti-human IFN_r (clone EPR1108, Abcam), anti-V5 tag (clone SV5-Pk1, Abcam), FITC mouse anti-human CD14 (clone M5E2, BD Pharmingen), PE mouse anti-human Human Leukocyte Antigen-antigen D Related (HLA-DR)(clone G46-6, BD Pharmingen) and PE Mouse Anti-Stat1 (pY701) (clone 4a, BD Phosflow).

[Detection and Titration of IFN_r Neutralizing Autoantibodies]

Blood plasma from patients and donors was serially diluted (10⁻¹ to 10⁻⁶) and incubated with recombinant human IFN_r at a final concentration of 200 pg/mL for 1 hour at 37° C. The IFN_r level was measured with a human IFN_r ELISA kit from BD Biosciences according to the manufacturer's recommendations. All experiments were performed in duplicate.

[Peptide Synthesis]

All peptides were synthesized by Kelowna International Scientific Inc., Taiwan. The peptides were lyophilized, and the purity and mass were assessed by high-performance liquid chromatography and mass spectrometry, respectively.

[Epitope Mapping]

Clear polystyrene 96-well flat bottom plates (Nunc) were coated with 100 μL of peptide solution (5 μg/mL) with b-carbonate buffer (pH 9.6) at 4° C. overnight. After blocking the remaining binding sites with 5% human normal serum albumin (Aventis) in PBS, the plates were incubated at 37° C. for 1 hour. Afterward, the plates were washed 3 times with 0.5% Tween 20 in PBS.

Blood plasma samples were added at a 1:100 dilution, in PBS containing 5% human normal serum albumin. Following incubation at room temperature for 2 hours and being washed 3 times, goat anti-human IgG Fc_r fragment specific conjugated with alkaline phosphate (Jackson ImmunoResearch Laboratories), was added at a 1:5000 dilution, and the plates were kept for 1 hour at room temperature. Finally, after being washed 5 times, 100 μL of p-Nitrophenyl Phosphate (pNPP) was added and the reaction was read at 405 nm by a VICTOR X3 Multilabel Plate Reader (PerkinElmer) after 30 minutes of incubation at 37° C.

[Competition Enzyme-Linked Immunosorbent Assay (ELISA)]

To evaluate the specificity of the reaction, a competition ELISA experiment was performed. Each plasma sample (1:100 dilutions) was pre-incubated with different concentrations (5-30 μg/mL) of the competition peptides overnight at 4° C. Subsequently, all plasma and different concentrations competition peptides mixture samples were examined following the epitope mapping protocol. Peptide 6 was coated with b-carbonate buffer (pH 9.6) at 4° C. overnight. After blocking at 37° C. for 1 hour, all pre-incubated plasma and different concentrations competition peptides mixture samples were added in duplicate. Following 2 hours of room temperature incubation, goat anti-human IgG Fc_r fragment specific conjugated with alkaline phosphate, was added. Finally, 100 μL of pNPP was added and the reaction was read at 405 nm by a VICTOR X3 Multilabel Plate Reader (PerkinElmer) after 30 minutes of incubation at 37° C.

[Prediction of B Cell Epitopes]

The prediction of B cell epitopes was carried out using BepiPred Linear epitope Prediction and Emini Surface Accessibility Prediction. The software takes a single sequence in FASTA format as an input. BepiPred predicts the location of linear B-cell epitopes using a combination of a hidden Markov model and a propensity scale method. In Emini Surface Accessibility Prediction, the calculation was based on surface accessibility scale of a product instead of an addition within the window. The accessibility profile was obtained using a special formula.

[Generation of Recombinant Human IFN_r]

The inventor amplified the IFN_r⋅ from base 196 to 624 of the open reading frame (ORF) by polymerase chain reaction (PCR) and cloned it into pMT/BiP/V5-His (Invitrogen) for Drosophila Schneider 2 (S2) cells expression. Recombinant IFN_r⋅ was further purified by V5 tagged protein purification kit (MBL). The mutated recombinant IFN_r⋅ was performed by QuickChange Site-Directed Mutagenesis kit (Stratagene). The inventor confirmed the sequences and cloning sites of all constructs as well as the size and immunoreactivity of the recombinant IFN_r⋅ by Western Blot.

[Generation of Recombinant Aspergillus Noc2]

The inventor amplified the Noc2 from base 1 to 2361 of the ORF by PCR and cloned it into pMT/BiP/V5-His (Invitrogen) for S2 cells expression. Recombinant Noc2 were further purified by a V5 tagged protein purification kit (MBL). Then, the sequences and cloning sites of all constructs were confirmed as well as the size and immunoreactivity of recombinant Noc2 by Western Blot.

[p-STAT1 Intracellular Stain]

A total of 10⁶ PBMCs in 200 μL RPMI-1640 with 10% FBS and 1% penicillin/streptomycin was used. Cells were then stimulated with 500 IU IFN_r, IFN_{r_}1-131 or EE-IFN_r□ in 160 μL RPMI-1640 pre-incubated with 40 μL of normal plasma or patient plasma for 10 min at room temperature. After 30 minutes of stimulation in a 37° C. incubator, monocytes were identified by FITC-CD14 (BD Pharmingen) surface staining. Fixed by adding 250 μL of FASC lysing solution (BD Pharmingen) and incubated at room temperature for 15 minutes in the dark, followed by two washes with PBS. To permeabilize the cells, 500 μl of ice-cold absolute methanol was added to each tube and incubated for 15 minutes on ice in the dark, followed by two washes with PBS. Next, PE-phospho-STAT1 (pY701) antibody (BD Pharmingen) was added, followed by 30 minutes incubation on ice in the dark. Again, cells were washed with 2 mL of PBS before resuspension in the 500 μL of PBS. Data were collected with a FACSVerse flow cytometer (BD Biosciences) and analyzed using FACSuite software (BD Biosciences).

[Immunoblotting]

Recombinant IFN_r□ (R&D Systems) and different truncated forms of recombinant IFN_r□ were subjected to SDS-PAGE using a 10% gel under reducing conditions at 120 V for 2 hours. The proteins were transferred to a PVDF membrane (Invitrogen Life Technologies) at 250 mA for 2 hours. The membrane was blocked in 5% human normal serum albumin (Aventis) in TBS with 0.1% Tween 20 overnight at 4° C. The membrane was incubated with a 1/100 dilution of patient or control blood plasma for 3 hours at room temperature. After being washed three times, the membrane was incubated in a 1/10,000 dilution of mouse anti-human IgG conjugated with horseradish peroxidase (Jackson ImmunoResearch Laboratories) for 1 hour at room temperature. After being washed three times, the membrane was developed with ECL (Merck Millipore).

[HLA-DR Expression]

A total of 10⁶ PBMCs in 200 μL RPMI-1640 with 10% FBS and 1% penicillin/streptomycin was used. Cells were then stimulated with 500 IU IFN_r, IFN_{r_}1-131 or EE-IFN_r⋅ in 160 μL RPMI-1640 pre-incubated with 40 μL of normal blood plasma or patient blood plasma for 10 min at room temperature. After 24 hours of stimulation in a 37° C. incubator, monocytes were identified by FITC-CD14 (BD Pharmingen) surface staining. Next, PE-HLA-DR antibody (BD Pharmingen) was added followed by 30 minutes of incubation on ice in the dark. Cells were again washed with 2 ml of PBS before resuspension in 500 μl of PBS. Data were collected with a FACSVerse flow cytometer (BD Biosciences) and analyzed using FACSuite software (BD Biosciences).

Immunization with Noc2 or IFN_r⋅ Peptide

The inventor immunized WKY/NcrlNarl rats with 0.25 mg Noc2 or IFN_r□ peptide (Noc2: CTPKTGKRKRSEQ (SEQ NO: 31); IFN_r: CAAKTGKRKRSQM (SEQ NO: 32)) conjugated with ovalbumin (OVA) and gave a booster dose every two weeks after the initial injection (day 0). After 70 days, the inventor checked the antibody production level by dot blot or ELISA at each injection. All rats were sacrificed ten days after the tenth injection (day 136) and whole blood was collected. After collection of the whole blood, the blood was allowed to clot by leaving it undisturbed at room temperature 15 minutes. Clots were removed by centrifuging at 1500 g for 10 minutes in a refrigerated centrifuge. Sera were aliquoted and stored at −20° C. for further use.

[Experimental Data]

Please refer to FIGS. 1a-1h, which are related to AutoAbs to IFN_r recognized C-terminal region of IFN_r.

FIG. 1a demonstrates amino acid sequences of human IFN_r⋅30-mer overlapping synthetic peptides.

FIG. 1b(1)-FIG. 1b(6) demonstrate epitope mapping for determining serum binding affinity of the synthetic peptide to IFN_r, represented as the mean optical density (OD) at 405 nm; plasma sample from IFN_r AutoAbs patients (n=15), Mycobacteria infected patients (n=2) and healthy controls (n=6).

FIG. 1c(1)-FIG. 1c(2) demonstrate the inhibition using ELISA, wherein each plasma sample from IFN_r⋅AutoAbs patients was pre-incubated with different concentrations of a control peptide or peptide 6, and then all plasma dilutions were examined by ELISA for reactivity against peptide 6.

FIG. 1d demonstrates a schematic diagram of IFN_r, and the prediction scores for linear B cell epitopes and surface acceptability regions. Each green bar represents a predicted B cell epitope, and each red bar represents a predicted surface acceptable region. The prediction scores represent the average scores for all amino acids within the region with prediction values above the cut-offs chosen for significance. The bar color intensities are proportional to the prediction scores found.

FIG. 1e demonstrates a three-dimensional projection of the structure of IFN_r. The epitope, amino acids 121-131 of IFN_r⋅ are located at the C-terminal and extend into the solvent.

FIG. 1f demonstrates a graphical representation of the different length of truncated recombinant IFN_r proteins.

FIG. 1g(1)-FIG. 1g(6) demonstrate protein mapping used to determine plasma binding affinity of the recombinant proteins to IFN_r, represented as the mean optical density (OD) at 405 nm; plasma sample from IFN_r⋅AutoAbs patients (n=16), Mycobacteria infected patients (n=2) and healthy controls (n=3).

FIG. 1h demonstrates a Western blot showing binding ability of blood plasma from IFN_r⋅AutoAbs patients (n=4, P1-4) and healthy controls (n=2, C1-2) to different truncated forms of IFN_r.

Please refer to Table 1, which demonstrates multiple amino acid sequence alignments of IFN_r in different species and EE-IFN_r (SEQ NO: 15-21). The conserved residues in the other species are boxed. The sequence of EE-IFN_r protein, which has substituted human P_121-127 Ser-Pro-Ala-Ala-Lys-Thr-Gly (SPAAKTG) (SEQ ID NO: 39) with homologous murine Leu-Pro-Glu-Ser-Ser-Leu-Arg (LPESSLR) addressing SEQ NO: 1 are in bold.

TABLE 1

In other embodiments, it is possible to apply homologous substitutes with various peptide lengths to replace the sequence in human P_121-127. For example, a homologous substitute comprises at least one amino acid capable of fulfilling at least one element loss in the epitope. For another example, a mutation procedure is applied in at least one element in the epitope.

FIG. 2a(1)-FIG. 2a(2) demonstrate the affinity of anti-IFN_r AutoAbs to IFN_{r_}1-131 and EE-IFN_r□□ by ELISA. Anti-IFN_r⋅AutoAbs from 5 patients' blood plasma was bound to IFN_{r_}1-131 in a dose dependent manner but not to EE-IFN_r⋅ represented as the mean optical density (OD) at 405 nm.

FIG. 2b demonstrates a Western blot analysis showing the binding of blood plasma from Anti-IFN_r□AutoAbs patients (n=4, P1-4) and healthy controls (n=2, C1-2) to IFN_r1-131 and EE-IFN_r. Plasma from 3 healthy donors had no response to either IFN_r1-131 or EE-IFN_r.

FIGS. 2c-2e demonstrate PBMCs from healthy controls that were pre-incubated with 20% Ctrl plasma (n=6) or anti-IFN_r AutoAbs patients' plasma (n=6) and treated with WT IFN_r, IFN_{r_}1-131 or EE-IFN_r□□ After being gated on the CD14⁺, p-STAT-1 levels were determined by flow cytometry with the p-STAT-1 monoclonal antibody. Representative histograms (FIG. 2c(1)-FIG. 2c(2)) and MFI (median fluorescence intensity) (FIG. 2d) are shown.

FIG. 2e demonstrates that PBMCs from healthy controls were pre-incubated with 20% Ctrl plasma (n=4) or anti-IFN_r AutoAbs patients' blood plasma (n=9) and stimulated with BCG BCG plus WT IFN_r, BCG plus IFN_{r_}1431 or BCG plus EE-IFN_r⋅⋅IL12p40 levels in the supernatant were measured by ELISA.

Table 2 demonstrates homologies in hIFN_r⋅ peptides P_125-133 to Aspergillus spp. Noc2 proteins. Amino acid numbers correspond to those of proteins published by The National Center for Biotechnology Information (NCBI). AA is an abbreviation for number of amino acids. And the proteins were sampled from Homo sapiens (SEQ NO: 22), Aspergillus terreus (SEQ NO: 23), Aspergillus fumigatus (SEQ NO: 24), Aspergillus flavus (SEQ NO: 25), Aspergillus nidulans (SEQ NO: 26), Aspergillus niger (SEQ NO: 27), Cryptococcus neoformans (SEQ NO: 28), Mycobacterium intracellulare (SEQ NO: 29) and Clostridium sp. MSTE9 (SEQ NO: 30).

TABLE 2
						Accession
Protein	Species	AA		AA	Positive	code
IFNγ P125-133	Homo sapiens	125	AAKTGKRKRSQML	133	—	GI:56786138
			(SEQ ID NO: 22)
Ribosome assembly	Aspergillus	105	TPKTGKRKRSEQQ	113	9/9 (100%)	GI:115397505
protein Noc2	terreus		(SEQ ID NO: 23)
Ribosome assembly	Aspergillus	100	TPKITGKRKRSEEQ	108	8/9 (89%)	GI:159131733
protein Noc2	fumigatus		(SEQ ID NO: 24)
Ribosome assembly	Aspergillus	102	TPKTGKRKRTEEQ	110	8/9 (89%)	GI:238483989
protein Noc2	flavus		(SEQ ID NO: 25)
Ribosome assembly	Aspergillus	103	SPKIGKRKRSETQ	111	8/9 (89%)	GI:67517347
protein Noc2	nidulans		(SEQ ID NO: 26)
Ribosome assembly	Aspergillus	102	TPKIGKRKRSDEQ	110	7/9 (78%)	GI:317025642
protein Noc2	niger		(SEQ ID NO: 27)
Hypothetical	Cryptococcus	623	LGSTGKRKRSSMG	631	7/9 (78%)	GI:405119493
protein CNAG_05000	neoformans		(SEQ ID NO: 28)
Hypothetical	Mycobacterium	124	NPAGGKRKRSQ--	132	7/9 (78%)	GI:379753578
protein OCO_15660	intracellulare		(SEQ ID NO: 29)
Diguanylate	Clostridium	14	KEQSKKRKRSQMT	22	6/9 (67%)	GI:496353461
cyclase	sp. MSTE9		(SEQ ID NO: 30)

FIG. 3a(1)-FIG. 3a(2) demonstrate epitope cross reaction mapping used to determine blood plasma binding affinity of the synthetic peptide to Aspergillus Noc2, represented as the mean optical density (OD) at 405 nm; blood plasma sample from IFN_r AutoAbs patients (n=9), Mycobacteria infected patients (n=3) and healthy controls (n=3).

FIG. 3b(1)-FIG. 3b(2) demonstrate inhibition of ELISA, where each plasma sample from IFN_r AutoAbs patients (n=7) was pre-incubated with different concentrations of control peptide or Aspergillus Noc2 peptide, then all plasma dilutions were examined by ELISA for reactivity against peptide 6.

FIG. 3c demonstrates a Western blot analysis showing binding of plasma form Anti-IFN_r⋅AutoAbs patients (n=4, P1-4) and healthy controls (n=2, C1-2) truncated Aspergillus Terreus (Amino Acid: 1-165) and Aspergillus Fumigatus (Amino Acid: 1-162) recombinant Noc2 protein.

FIG. 3d(1)-FIG. 3d(4) demonstrate immunization with Noc2 peptide induced antibodies to IFN_r. Blood sera from pre-immunized rats (n=6), Noc2 peptide-immunized rats (n=4) and Peptide 6-immunized rats (n=2) were mapped to control peptide, Peptide 6 and Noc2 peptide from Aspergillus terreus or Aspergillus fumigatus. This is represented as the mean optical density (OD) at 405 nm.

FIG. 3e demonstrates blood sera from pre-immunized rats (n=2), Noc2 peptide-immunized rats (n=4) and Peptide 6-immunized rats (n=2) were serially diluted and incubated with 200 pg/mL of human IFN_r. Sera from pre-immunized rats showed no blocking activities for the detection of hIFN_r. However, blood sera from Noc2 peptide-immunized rats (n=4) and Peptide 6-immunized rats (n=2) at dilutions of up to 1/10² inhibited the detection of hIFN_r.

FIGS. 3f-3g demonstrate that THP1 cells were pre-incubated with 50% blood sera from pre-immunized rats (n=2), Noc2 peptide-immunized rats (n=4) or Peptide 6-immunized rats (n=2) and treated with WT IFN_r⋅⋅p-STAT-1 levels were determined by flow cytometry with the p-STAT-1 monoclonal antibody, MFI (median fluorescence intensity) are shown in FIG. 3f HLA-DR expression levels were determined by flow cytometry with the HLA-DR monoclonal antibody, and MFI are shown in FIG. 3g.

FIGS. 4a-4b demonstrate that PBMCs from healthy controls (n=5) or anti-IFN_r AutoAbs patients (n=6) were pre-incubated with 20% autologous plasma and treated with WT IFN_r, IFN_r1-131 or EE-IFN_r. After being gated on the CD14⁺, p-STAT-1 levels were determined by flow cytometry with the p-STAT-1 monoclonal antibody. Representative histograms (FIG. 4a(1)-FIG. 4a(2)) and MFI (median fluorescence intensity) (FIG. 4b) are shown.

FIG. 4c demonstrates that PBMCs from healthy controls (n=3) or anti-IFN_r AutoAbs patients (n=6) were pre-incubated with 20% autologous blood plasma and stimulated with BCG BCG plus WT IFN_r, BCG plus IFN_{r_}1-131 or BCG plus EE-IFN_r⋅⋅IL12p40 levels in the supernatant were measured by ELISA.

FIGS. 4d-4e demonstrate that PBMCs from healthy controls (n=5) or anti-IFN_r AutoAbs patients (n=4) were pre-incubated with 20% autologous plasma and treated with WT IFN_r, IFN_{r_}1-131 or EE-IFN_r. After being gated on the CD14⁺, HLA-DR expression levels were determined by flow cytometry with the HLA-DR monoclonal antibody. Representative histograms (FIG. 4d(1)-FIG. 4d(2)) and MFI (median fluorescence intensity) (FIG. 4e) are shown.

FIGS. 4f-4g demonstrate that whole blood from healthy controls (n=4) or anti-IFN_r AutoAbs patients (n=6) was treated with WT IFN_r, IFN_{r_}1-131 or EE-IFN_r⋅ ⋅ After being gated on the CD14⁺, p-STAT-1 levels were determined by flow cytometry with the p-STAT-1 monoclonal antibody. Representative histograms (FIG. 4f(1)-FIG. 4f(2)) and MFI (median fluorescence intensity) (FIG. 4g) are shown.

FIG. 4h demonstrates that whole blood from healthy controls (n=4) or anti-IFN_r AutoAbs patients (n=5) was stimulated with BCG BCG plus WT IFN_r, BCG plus IFN_{r_}1-131 or BCG plus EE-IFN_r⋅IL12p40 levels in the supernatant were measured by ELISA.

FIG. 5 demonstrates that direct ELIAS was used to detect AutoAbs against IFN_r. Represented as the mean optical density (OD) at 405 nm; blood plasma samples from IFN_r AutoAbs patients (n=2), and healthy controls (n=65) are shown.

FIG. 6a demonstrates that IL-12 production levels were measured by ELISA after non-activated, BCG activated or BCG plus IFN_r activated in whole blood from three groups individuals were tested. IFN_r AutoAbs patients (n=3), healthy controls without AutoAbs (n=7), and healthy controls with non-neutralizing IFN_r⋅AutoAbs (n=4) are shown.

FIG. 6b demonstrates that IFN_r production levels were measured by ELISA after non-activated, BCG activated or BCG plus IL-12 activated in whole blood from three groups individuals were tested. IFN_r AutoAbs patients (n=3), healthy controls without AutoAbs (n=7), and healthy controls with non-neutralizing IFN_r⋅AutoAbs (n=4) are shown.

FIG. 7 demonstrates epitope mapping used to determine plasma binding affinity of the synthetic peptide to IFN_r, represented as the mean optical density (OD) at 405 nm including plasma samples from IFN_r AutoAbs patients (n=3, P1-3), healthy controls without AutoAbs (n=2, C1-2), and healthy controls with non-neutralizing IFN_r⋅AutoAbs (n=5, N1-5).

FIG. 8 demonstrates a Western blot analysis showing the expression of different forms of recombinant IFN_r by a V5-tag antibody.

FIG. 9 demonstrates blood plasma sampled from IFN_r⋅AutoAbs patients (n=5, P1-5) and healthy controls (n=2, C1-2) were probes for vector, IFN_{r_}1-50, IFN_{r_}1-70, IFN_{r_}68-121, IFN_{r_}1-121, IFN_{r_}1-131, and IFN_{r_}1-139 recombinant proteins.

FIG. 10 demonstrates protein mapping used to determine blood plasma binding affinity of the recombinant proteins to IFN_r, represented as the mean optical density (OD) at 405 nm including blood plasma samples from healthy controls without AutoAbs (n=3, C1-3), and healthy controls with non-neutralizing IFN_r⋅AutoAbs (n=5, N1-5).

FIGS. 11a-11b demonstrate that seven patients' blood plasma was serially diluted and incubated with 200 pg/mL of human IFN_r (hIFN_r) or murine IFN_r (mIFN_r). The blood plasma from healthy donors showed no blocking activities for the detection of hIFN_r or mIFN_r. However, plasma from patients with AutoAbs against IFN_r at dilutions of up to 1/10⁴ inhibited the detection of hIFN_r but showed no blocking activity for the detection of mIFN_r.

FIG. 12 demonstrates a Western blot analysis showing the expression of different forms of recombinant Noc2 by V5-tag antibody.

FIGS. 13a-13b demonstrate that THP1 cells were pre-incubated with 50% Sera from pre-immunized rats (n=2), Noc2 peptide-immunized rats (n=4) or Peptide 6-immunized rats (n=2) and treated with WT IFNγ p-STAT-1, and levels were determined by flow cytometry with the p-STAT-1 monoclonal antibody, wherein representative histograms (FIG. 13a(1)-FIG. 13a(2)) are shown. HLA-DR expression levels were determined by flow cytometry with the HLA-DR monoclonal antibody, wherein representative histograms (FIG. 13b(1)-FIG. 13b(2)) are shown.

[Embodiment I] Anti-IFN_r Autoantibodies Recognize a C-Terminal Region in IFN_r Peptide⋅

The inventor tried to identify the epitope recognized by anti-IFN_r AutoAbs isolated from patients by peptide scan: Six 30-mer peptides, overlapping by a 7 or 8 amino acids and covering the entire coding sequence of human IFN_r, were synthesized, and the amino acids sequences of peptides addressing SEQ NOS: 2 to 7 were listed (FIG. 1a). Epitope mapping assay was performed using plasma from three different patient groups: anti-IFN_r AutoAbs patients with disseminated mycobacterial infections (n=15, group-1), patients with mycobacterial infections without anti-IFN_r AutoAbs (n=2, group-2), and healthy controls (n=6, group-3). It was found that only peptide 6 was recognized in the blood plasma isolated from the 12 patients in group-1 (FIG. 1b(1)-FIG. 1b(6)). In contrast, no binding activity to these six peptides was observed in other two patient groups and this observation suggests that recognition of the peptide 6 was not due to a cross-reaction of anti-mycobacterial antibodies. Next, competition ELISA was used to confirm the specificity of the anti-IFN_r AutoAbs to the peptide 6. Blood plasma from group-1 patients was pre-incubated with peptide 6, which led to competition for the binding with coated peptide 6 in a dose dependent manner, and no competition was observed when the control peptides (peptide 1-5) were used as competitors (FIG. 1c(1)-FIG. 1c(2)). These data suggest that the anti-IFN_r AutoAbs from group-1 patients was recognized by one major region in the peptide 6 (P_114-143).

In contrast to neutralizing AutoAbs to IFN_r⋅ in patients with mycobacterial infections, non-neutralizing AutoAbs against IFN_r had been reported in healthy individuals. Five donors were found with AutoAbs against IFN_r out of 65 healthy controls by ELISA (FIG. 5). AutoAbs from these five healthy individuals showed a non-neutralizing effect on IFN_r in terms of induction of IL-12 production. In contrast to neutralizing IFN_r⋅AutoAbs from patients, non-neutralizing AutoAbs from healthy donors did not recognize peptide 6 (FIG. 8). These data indicate that the IFNγ AutoAbs from patients with disseminated mycobacterial infections, but not non-neutralizing IFNγ AutoAbs, recognized a major region on peptide 6.

[Embodiment II] Predictions of B-Cell Epitopes Using Computer Modeling

For further confirmation of the precise region recognized by anti-IFN_r AutoAbs, the inventor scanned the primary sequence of IFN_r for possible B-cell linear epitopes and possible surface acceptability in silico. It was found several candidate epitopes addressing SEQ NO: 8-14 in the full length IFN_r⋅(FIG. 1d). Considering the higher prediction scores for screening features and located in the peptide 6, the epitope P_121-131 SPAAKTGKRKR (SEQ ID NO: 33) was predicted in B-cell epitope prediction algorithms and P_126-131 TGKRKR (SEQ ID NO: 37) was predicted in Surface Acceptability prediction algorithms. These results were consistent with peptide epitope mapping data. The critical epitope P_121-131 SPAAKTGKRKR (SEQ ID NO: 33) that we identified is located on an unfolded sequence in the C-terminal region. It extends into the solvent and does not strongly interact with the remainder of the molecules (FIG. 1e).

[Embodiment III] Anti-IFN_r Autoantibodies Recognize a C-Terminal Region in IFN_r⋅ Protein

In order to investigate whether anti-IFN_r AutoAbs from group-1 patients recognized the same region in the native IFN_r protein, we generated various truncated IFN_r by Schneider 2 cell expression system (FIG. 1f and FIG. 9). It was found that only full-length IFN_r (IFN_{r_}1-144) and deletion clone IFN_{r_}1-131 were recognized by blood plasma isolated from the group-1 patients (FIG. 1g(1)-FIG. 1g(6)). In contrast, blood plasma isolated from the group-2 and group-3 patients did not recognize all the recombinant IFN_r tested. In Western blot and dot blot assays, we also observed similar phenomena that only full-length IFN_{r_}1-144 (data not shown) and deletion clone IFN_{r_}1-139 and IFN_{r_}1-131 were recognized by anti-IFN_r AutoAbs, but not other truncates IFN_r⋅(FIGS. 1h and 10). These data suggest that a major anti-IFN_r□AutoAbs-recognized B-cell epitope, P_121-131 (SPAAKTGKRKR) (SEQ NO: 33) was located at the C-terminal of IFN_r.

[Embodiment IV] EE-IFNγ

Inside the epitope region we identified, a.a. 128-131 (KRKR) (SEQ ID NO: 38) (the last 4 resides in SEQ NO: 20) is crucial for the bioactivity of IFN_r□ and conserved in most species.

Nevertheless, a.a. 121-127 is less conserved among different species (human: SPAAKTG (SEQ ID NO: 39) (the 6^th-12^th resides in SEQ NO: 20); murine: LPESSLR (SEQ NO: 1)) (Table 1).

It had been observed that blood plasma from randomly selected patients with anti-IFN_r AutoAbs did not show blocking activity on the murine IFN_r (FIG. 12), which suggests that SPAAKTG (the 6^th-12^th resides in SEQ NO: 20) is a necessary component for the binding of anti-IFN_r AutoAbs. Previous studies demonstrated that the precise sequence in a.a. 121-127 was not critical for IFN_r functions, and the deletion of some amino acids from the C-terminal of human IFN_r resulted in increasing bioactivity.

Following these observations, the inventor generated an EE-IFN_r protein by substituting the human P_121-127 SPAAKTG sequence (SEQ ID NO: 39) (the 6^th-12^th resides in SEQ NO: 20) with murine LPESSLR sequence (SEQ NO: 1) in the IFN_{r_}1-131 protein (Table 1).

In other embodiments, EE-IFNγ may be further combined with pharmaceutically acceptable excipients or carriers for clinical use.

The excipient in the present invention also refers to a pharmaceutically acceptable carrier or excipient, or a bio-available carrier or excipient, including a solvent, dispersant, coating, antibacterial or antifungal agent, preservative or slow absorber, which is a proper compound used to prepare a formulation in the prior art. Usually such a carrier or excipient does not have any activity for treatments itself. And the compound disclosed in the present invention cooperating with a pharmaceutically acceptable carrier or excipient is prepared as various formulations, and will not result in adverse drug reactions, allergies or other inappropriate responses after it is administered to animals or humans. Thus the compound in the present invention, cooperating with a pharmaceutically acceptable carrier or excipient, can be used in clinics and humans.

“Effective dose” means a dose which is enough to improve or prevent medical symptoms or biological manifestation. The effective dose may be also stated as a casting dose for use in diagnosis. Unless there is another description in the specification, “active compound” and “pharmaceutically active compound” are substitutes for each other and refer to a pharmaceutical, pharmacological or therapeutic substance as well as other effective material.

Using ELISA, we observed that the affinity of anti-IFN_r AutoAbs to EE-IFN_r was markedly decreased in comparison with wild type (WT) IFN_{r_}1-131 (FIG. 2a(1)-FIG. 2a(2)). With the aid of Western blot, again, we observed a similar different affinity to anti-IFN_r AutoAbs between EE-IFN_r and WT IFN_{r_}1-131 (FIG. 2b). These data suggest that the epitope of anti-IFN_r AutoAbs is located in a.a. 121-131 and SPAAKTG was a necessary component for recognition.

[Embodiment V] Anti-IFN_r AutoAbs to Epitope P_121-131 have Neutralizing Activity on IFN_r

The inventor aimed to know if anti-IFN_r AutoAbs to epitope P_121-131 played a critical role in the neutralizing effect in an anti-IFN_r AutoAbs disease. A previous study showed that substitution of the homologous murine sequence between residue 121 and residue 127 resulted in only a small decrease in biological activity. The biological activity of EE-IFN_r was tested by measuring the phosphorylation of signal transducers and activators of transcription 1 (p-STAT1) signaling assay by flow cytometry and interleukin-12 (IL-12) production through ELISA. Up-regulation of the p-STAT1 signaling was observed in the controls' peripheral blood mononuclear cells (PBMCs) that were activated with recombinant IFN_r, WT IFN_{r_}1-131, or EE-IFN_r in the presence of 20% control blood plasma, which demonstrated that EE-IFN_r had similar bioactivity with WT IFN_{r_}1-131 in the p-STAT1 signaling (FIGS. 2c and 2d). In pre-incubated with 20% blood plasma with anti-IFN_r AutoAbs from patients, only EE-IFN_r, but not recombinant IFN_r or WT IFN_{r_}1-131, could induce the phosphorylation of STAT1. These data strongly suggest that the anti-IFN_r AutoAbs had neutralizing effects specific to epitope P_121-131. IFN_r could increase the synthesis and expression of HLA-DR in myeloid cells and other cells types. Therefore, the HLA-DR expression after IFN_r stimulation was measured. Similarly, up-regulation of HLA-DR expression, a process activated by IFN_r, in THP1 cells was observed while stimulated with EE-IFN_r, even in the presence of anti-IFN_r AutoAbs. Similar to STAT1 and HLA-DR signaling, the elevation of IL-12p40 expression couldn't be observed when pre-incubated with 20% patients' blood plasma and stimulated with BCG plus recombinant IFN_r or IFN_{r_}1-131. In contrast, BCG plus EE-IFN_r did restore IL-12p40 expression in the controls' PBMC pre-incubated with 20% patients' blood plasma (FIG. 2e). These data indicated epitope P_121-131 was the only or major binding site for anti-IFN_r AutoAbs in different patients, in terms of the blocking effect.

[Embodiment VI] IFN_r Epitope P_125-133 is Homologous to Aspergillus Conserved Protein

Recognition of a common epitope and shared HLA haplotypes among the patients with Anti-IFN_r AutoAbs suggest that a common pathogenesis mechanism of molecular mimicry might be involved. To test this possibility, the inventor used P_121-135 a.a. sequence (SPAAKTGKRKRSQML) (SEQ NO: 34) to search for similar peptides in the human and microbe database. No similarity between this region and other human protein was observed; however it was found that the P_125-133 epitopes had 100% positives with amino acids 105-113 of the ribosome assembly protein Noc2 (with eight of the nine amino acids identical) from Aspergillus terreus, and this region in Noc2 was conserved among most Aspergillus spp. available in the database (Table 2).

[Embodiment VII] IFN_r AutoAbs could Cross-React with Aspergillus Noc2

Next, the inventor investigated whether IFN_r AutoAbs from patients could cross-react with Aspergillus Noc2. First, the antigenicity of the synthetic Aspergillus Noc2 peptide (KKDVTPKTGKRKRSEQQKDE (SEQ NO: 35)) was measured, which was evaluated by epitope mapping assay using blood plasma isolated from patients with anti-IFN_r AutoAbs (FIG. 3a(1)-FIG. 3a(2)). This data show that the Aspergillus Noc2 peptide was recognized by blood plasma isolated from patients with anti-IFN_r AutoAbs, but it did not react with blood plasma from mycobacterial infected patients without AutoAbs to IFN_r (FIG. 3a(1)-FIG. 3a(2)). The homogeneity between human IFN_r P_125-133 and Aspergillus Noc2 in the conserved region P_105-113 was further assessed by competition ELISA. Samples isolated from patients with anti-IFN_r AutoAbs were pre-incubated with Aspergillus Noc2 peptide, and then reacted with the peptide 6. The data show that the Aspergillus Noc2 peptide would compete for IFN_r AutoAbs binding with peptide 6 in a dose dependent manner and no competition was observed when the control peptides were used as competitors (FIG. 3b(1)-FIG. 3b(2)). These data suggest that the human IFN_r AutoAbs could cross-react with the Aspergillus Noc2 peptide.

[Embodiment VIII] Autoantibodies to IFN_r Recognized Aspergillus Noc2

To further investigate whether AutoAbs against IFN_r could recognize the Aspergillus Noc2 in the protein level, we generated truncated recombinant Noc2 protein P_1-165 and P_1-162 from Aspergillus Terreus and Aspergillus Fumigatus. A Western blot assay was performed to examine the cross-reaction of anti-IFN_r AutoAbs between human IFN_r and Aspergillus Noc2. Utilizing blood plasma from patients with anti-IFN_r AutoAbs as the primary antibodies, it was found that anti-IFN_r AutoAbs recognize truncated recombinant Noc2 proteins from different Aspergillus species. In contrast, blood plasma from healthy controls could not bind to truncated recombinant Noc2 proteins or WT IFN_{r_}1-131 protein (FIG. 3c). These data provide evidence that anti-IFN_r AutoAbs from patients could cross-reacts with the Aspergillus Noc2 protein.

[Embodiment IX] Noc2 Immunization Induces Antibodies to IFN_r

In order to investigate the immunogenicity to induce the anti-IFN_r AutoAbs to epitope P_121-131 in vivo, the inventor immunized four rats with synthetic a.a. 103-114 Aspergillus Noc2 peptide conjugated with ovalbumin (OVA). These rats developed anti-Noc2 antibodies that cross-reacted with human IFN_r (FIG. 3d(1)-FIG. 3d(4)). Two rats immunized with synthetic a.a.123-134 human IFN_r peptide conjugated with OVA also developed antibodies to human IFN_r, which could cross-react with Aspergillus Noc2 (FIG. 3d(1)-FIG. 3d(4)). Moreover, it was found that all sera from rats immunized with Noc2 peptide as well as those immunized with IFN_r peptide can block human recombinant IFN_r (FIG. 3e). These data indicate that antibodies to Aspergillus Noc2 could cross-react with human IFN_r in vivo and vice versa.

Next, the inventor checked if these Noc2 antibodies had a neutralizing ability on the IFN_r signaling pathway. Using a p-STAT1 signaling assay by flow cytometry, it was observed that p-STAT1 signaling was up-regulated in THP1 cells while pre-incubated with 50% sera from non-immunized rats and stimulated with recombinant IFN_r. However, decreased up-regulation of p-STAT1 signaling in THP1 cells was observed while pre-incubated with 50% Noc2 or IFN_r immunized rats sera was stimulated with recombinant IFN_r (FIG. 3f). Similar results were also be observed in an HLA-DR expression assay (FIG. 3g). These data indicate that antibodies to Aspergillus Noc2 not only bind to human IFN_r, but also inhibit IFN_r downstream signaling. Thus, rats immunized with Noc2 had a break in the immunological tolerance to IFN_r and anti-IFN_r antibodies were evoked through the process of molecular mimicry.

[Embodiment X] EE-IFN_r Application in Anti-IFN_r AutoAbs Therapy Ex Vivo

The inventor showed that EE-IFN_r could restore IFN_r activated STAT-1 signaling and promote IL-12/HLA-DR expression in control PBMCs/THP1 cells with the presence of anti-IFN_r AutoAbs (FIGS. 2d-2f). Consequently, we investigated the possibility of using EE-IFN_r to restore the IFN_r function in patients with anti-IFN_r AutoAbs ex vivo. Patients' PBMCs were pre-incubated with 10% autologous blood plasma and stimulated with EE-IFN_r or BCG plus EE-IFN_r to measure p-STAT1 signaling or IL-12 production. It was observed that up-regulated p-STAT1 signaling cannot be observed when IFN_r AutoAbs patients' PBMCs are pre-incubated with 10% autologous blood plasma and stimulated with recombinant IFN_r and WT IFN_{r_}1-131. In contrast, EE-IFN_r could restore p-STAT1 signaling in four of six IFN_r AutoAbs patients' PBMCs pre-incubated with 10% autologous blood plasma (FIGS. 4a-4b). Moreover, BCG plus EE-IFN_r could restore IL-12p40 production in three of six IFN_r AutoAbs patients' PBMCs pre-incubated with 10% autologous blood plasma in contrast to BCG plus recombinant IFN_r or plus WT IFN_{r_}1-131 (FIG. 4c). The similar phenomena was also be observed in an HLA-DR expression assay. It was found that up-regulated HLA-DR expression levels were not observed when IFN_r AutoAbs patients' PBMCs was pre-incubated with 10% autologous blood plasma and stimulated with recombinant IFN_r and WT IFN_{r_}1-131. In contrast, EE-IFN_r could restore the HLA-DR expression levels in four of six IFN_r AutoAbs patients' PBMCs that were pre-incubated with 10% autologous plasma (FIGS. 4d-4e).

Next, the inventor examined EE-IFN_r bioactivity to restore IFN_r receptor activation in IFN_r AutoAbs patients' whole blood ex vivo. The p-STAT1 signal was up-regulated in controls' whole blood after being stimulated with recombinant commercial IFN_r, WT IFN_{r_}1-131 or EE-IFN_r. The up-regulated p-STAT1 signaling was not found when IFN_r AutoAbs patients' whole blood was stimulated with recombinant IFN_r and WT IFN_{r_}1-131. In contrast, EE-IFN_r could restore p-STAT1 signaling in four of six IFN_r AutoAbs patients' whole blood (FIGS. 4f-4g). Moreover, BCG plus EE-IFN_r could restore IL-12p40 production in three of six IFN_r AutoAbs patients' whole blood in contrast to BCG plus commercial IFN_r or plus WT IFN_{r_}1-131R (FIG. 4h). Taking these data together, EE-IFN_r could restore bioactivity not only in IFN_r AutoAbs patients' autologous plasma but also in their whole blood ex vivo.

In conclusion, the inventor identified a major epitope in the C-terminal of IFN_r recognized by anti-IFN_r AutoAbs, and these AutoAbs could cross-react with Aspergillus Noc2 protein. The inventor hypothesizes that in the presence of specific HLA class II alleles, neutralizing anti-IFN_r AutoAbs, which recognized a limited epitope P_121-131 in the C-terminal of IFN_r, were triggered by Noc2 protein through the mechanism of molecular mimicry. Moreover, the inventor generated a potential therapeutic EE-IFN_r, which could restore the IFN_r signaling pathway in the presence of patients' blood samples ex vivo. These data suggest that the anti-IFN_r AutoAbs to P_121-131 is the one or the only crucial AutoAbs which causes this disease. These findings provide a new model for the pathogenesis of disseminated mycobacterial infections caused by anti-IFN_r AutoAbs and a new therapeutic strategy for this devastating disease.

Further Embodiments

1. A method for evaluating an efficacy of an isolated recombinant human interferon gamma (hIFN_r) for regulating a peripheral blood mononuclear cell (PBMC), comprising the steps of:

• • providing the PBMC from a subject with anti-interferon gamma autoantibodies;
  • mixing the isolated recombinant human interferon gamma with the PBMC, wherein the isolated recombinant human interferon gamma contains a homologous substitute; and
  • evaluating the efficacy of the isolated recombinant human interferon gamma according to an expression level of a phosphorylation of signal transducers and activators of transcription 1 (p-STAT1) generated by the PBMC.2. The method as claimed in Embodiment 1, wherein the isolated recombinant human interferon gamma is produced by the following steps:
  • determining an epitope of a subject suffering from a disseminated mycobacterial infection, the epitope is chosen from at least one residue in a human interferon gamma; and
  • applying a mutation procedure to the at least one residue to activate a receptor of the human interferon gamma which is not neutralized by an autoantibody of the human interferon gamma.3. The method as claimed in Embodiment 1, wherein the recombinant human interferon gamma is characterized by an epitope of a subject suffering from a disseminated mycobacterial infection; and
  • the homologous substitute substitutes for at least one residue in the epitope.4. The method as claimed in Embodiment 3, wherein the epitope is located between residue 121 and 127 from a C-terminal of a human interferon gamma.5. The method as claimed in Embodiment 3, wherein the homologous substitute includes a peptide “Leu-Pro-Glu-Ser-Ser-Leu-Arg” (SEQ NO: 1).6. The method as claimed in Embodiment 3, wherein the recombinant human interferon gamma further includes one of a pharmaceutically acceptable excipient and a pharmaceutically acceptable carrier.7. The method as claimed in Embodiment 3, wherein the recombinant human interferon gamma up-regulates the expression level of the p-STAT1 demonstrating a bioactivity of a hIFN_r⋅⋅⋅8. A method for evaluating an efficacy of an isolated recombinant cytokine for regulating a peripheral blood mononuclear cell (PBMC), comprising the steps of:
  • providing the PBMC from a subject with an anticytokine autoantibody;
  • mixing the isolated recombinant cytokine with the PBMC, wherein the isolated recombinant cytokine contains a homologous substitute; and
  • evaluating the efficacy of the isolated recombinant cytokine according to an expression level of an interleukin-12 (IL-12) generated by the PBMC.9. The method as claimed in Embodiment 8, wherein the isolated recombinant human interferon gamma is produced by the following steps:
  • determining an epitope of a subject suffering from a disseminated mycobacterial infection, wherein the epitope lacks at least one residue in the amino acid sequence; and
  • substituting the homologous substitute for the at least one residue in the epitope.10. The method as claimed in Embodiment 9, wherein the epitope is located between residue 121 and 127 from a C-terminal of a human interferon gamma.11. The method as claimed in Embodiment 9, wherein the homologous substitute includes a peptide “Leu-Pro-Glu-Ser-Ser-Leu-Arg” (SEQ NO: 1).12. A recombinant protein □, comprising:a human interferon gamma having a sequence replaced by a peptide of “Leu-Pro-Glu-Ser-Ser-Leu-Arg”, wherein the recombinant protein is used to activate a receptor of an interferon gamma (IFN_r) and is free from neutralization by an autoantibody of the interferon gamma of a subject suffering from a disseminated mycobacterial infection.13. The recombinant protein as claimed in Embodiment 12, wherein the subject is immunized with a human interferon gamma.14. The recombinant protein as claimed in Embodiment 12, wherein the subject is immunized with Aspergillus Noc2.15. The recombinant protein as claimed in Embodiment 12, wherein the sequence has a C-terminal and is located between residue 121 and 127 from the C-terminal.16. The recombinant protein as claimed in Embodiment 15, wherein the recombinant protein is characterized by an expression of a phosphorylation of signal transducers and activators of transcription 1 (p-STAT1).17. The recombinant protein as claimed in Embodiment 15, wherein the recombinant protein is characterized by an expression of an interleukin-12 (IL-12).18. The recombinant protein as claimed in Embodiment 15, wherein the recombinant protein is characterized by an expression of Human Leukocyte Antigen-antigen D Related (HLA-DR) expression.19. The recombinant protein as claimed in Embodiment 15, wherein the recombinant protein further includes one of a pharmaceutically acceptable excipient and a pharmaceutically acceptable carrier.20. The recombinant protein as claimed in Embodiment 15, wherein the C-terminal of the human interferon gamma is recognized by the autoantibody of the interferon gamma.

While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.

Claims

1. A method for evaluating an efficacy of an isolated recombinant human interferon gamma (rhIFNγ) for regulating a peripheral blood mononuclear cell (PBMC), comprising the steps of: providing the PBMC from a subject with anti-interferon gamma autoantibodies;mixing the isolated recombinant human interferon gamma (rhIFNγ) with the PBMC, wherein the isolated recombinant human interferon gamma (rhIFNγ) is produced by replacing at least one residue which is located between residues 121 and 127 from a C-terminal of an epitope of a human interferon gamma (hIFNγ) SEQ ID NO: 39 via homologous substitution; andevaluating the efficacy of the isolated recombinant human interferon gamma (rhIFNγ) according to an expression level of a phosphorylation of signal transducers and activators of transcription 1 (p-STAT1) generated by the PBMC.

2. The method as claimed in claim 1, wherein homologous substitution consists of SEQ ID NO: 1.

3. The method as claimed in claim 2, wherein the isolated recombinant human interferon gamma (rhIFNγ) further includes a pharmaceutically acceptable excipient or a pharmaceutically acceptable carrier.

4. The method as claimed in claim 2, wherein the isolated recombinant human interferon gamma (rhIFNγ) up-regulates the expression level of the p-STAT1.

5. A method for evaluating an efficacy of an isolated recombinant human interferon gamma (rhIFNγ) for regulating a peripheral blood mononuclear cell (PBMC), comprising the steps of: providing the PBMC from a subject with anti-interferon gamma autoantibodies; mixing the isolated recombinant human interferon gamma (rhIFNγ) with the PBMC, wherein the isolated recombinant human interferon gamma (rhIFNγ) is produced by replacing residues which is located between residues 121 and 127 from a C-terminal of an epitope of a human interferon gamma (hIFNγ) of SEQ ID NO: 39 via homologous substitution of SEQ ID NO: 1; and evaluating the efficacy of the isolated recombinant human interferon gamma (rhIFNγ) according to an expression level of a phosphorylation of signal transducers and activators of transcription 1 (p-STAT1) generated by the PBMC.