Patent Application
20250180587
The present invention belongs to the field of blood group antibody detection, and relates to use of a blood group antigenic trisaccharide conjugate in the blood group antibody detection, in particular to use of a blood group antigenic trisaccharide A analogue-protein conjugate and a blood group antigenic trisaccharide B analogue-protein conjugate in the blood group antibody detection.
Blood grouping is a primary job before clinical blood transfusion. When blood is transfused into the blood of different blood groups, due to the agglutination of antigens and antibodies, hemolysis will occur, which may endanger human life safety. Thus, correct blood grouping is a prerequisite for ensuring the safety of blood transfusion. Current blood grouping methods include forward grouping and reverse grouping. Erythrocyte antigens are detected in the forward grouping, and antibodies in the serum are detected in the reverse grouping, wherein the detection of human A, B, O blood group antigens/antibodies is the most important. Human blood can be divided into different blood groups according to different surface antigens of erythrocyte membranes. Group A blood has a blood group antigen A (hereinafter referred to as “antigen A”) on the erythrocyte with a blood group antibody B (hereinafter referred to as “antibody B”) in the serum. Group B blood has a blood group antigen B (hereinafter referred to as “antigen B”) on the erythrocyte with a blood group antibody A (hereinafter referred to as “antibody A”) in the serum. Group AB blood has both the antigen A and the antigen B on the erythrocyte without the antibody A or the antibody B in the serum. Group O blood has neither the antigen A nor the antigen B on the erythrocyte with both the antibody A and the antibody B in the serum.
At present, an agglutination method is generally used in common forward grouping and reverse grouping of blood groups, and its principle is to use blood group antigens to react with antibodies to cause erythrocyte agglutination that is visible with naked eyes, to judge results. During forward grouping, an IgM anti-A or anti-B reagent is used to detect erythrocyte antigens of samples. During reverse grouping, a known group A or B erythrocyte reagent is used to determine IgM blood group antibodies in the serum sample. However, since fresh erythrocytes are not easy to preserve (the antigenicity of blood group antigens on surfaces of the erythrocytes gradually decreases with the extension of preservation time), the group A or B erythrocyte reagent for reverse grouping detection has higher requirements for preservation conditions and transportation conditions, which increases the cost for the reverse grouping detection and limits the use of the reverse grouping detection. Some technical solutions in the prior art attempt to extract natural blood group antigens (for example, to extract natural antigens A and antigens B from the erythrocyte membranes) to replace intact erythrocytes in the reverse grouping detection. However, the relevant extraction and preparation processes are often more complex and uneasy for mass production, and the extracted natural blood group antigens still have higher requirements for the preservation conditions. Artificial synthesis of blood group antigens is one of the research directions to solve the above technical problems, but it is currently known that the artificially synthesized blood group antigens have technical problems in specificity, affinity, stability, etc. and cannot be effectively applied to the reverse grouping detection.
In view of this, the present invention provides use of a blood group antigenic trisaccharide conjugate in preparation of a blood group antibody detection reagent, the blood group antigenic trisaccharide conjugate is a blood group antigenic trisaccharide analogue-protein conjugate; the blood group antigenic trisaccharide analogue includes a blood group antigenic trisaccharide B analogue; the blood group antigenic trisaccharide B analogue is conjugated to a keyhole limpet hemocyanin (KLH) or a bovine serum albumin (BSA) to form a blood group antigenic trisaccharide B analogue-protein conjugate; when the blood group antigenic trisaccharide B analogue is a type B2, a conjugation ratio of the blood group antigenic trisaccharide B analogue to the keyhole limpet hemocyanin is 5:1-40:1, and a conjugation ratio of the blood group antigenic trisaccharide B analogue to the bovine serum albumin is 20:1; when the blood group antigenic trisaccharide B analogue is a type B1, a type B3 or a type B4, a conjugation ratio of the blood group antigenic trisaccharide B analogue to the keyhole limpet hemocyanin is 40:1.
In some embodiments, when the blood group antigenic trisaccharide B analogue is the type B2, a conjugation ratio of the blood group antigenic trisaccharide B analogue to the keyhole limpet hemocyanin is 20:1.
In some embodiments, the blood group antigenic trisaccharide analogue further includes a blood group antigenic trisaccharide A analogue; the blood group antigenic trisaccharide A analogue is conjugated to the keyhole limpet hemocyanin or the bovine serum albumin to form a blood group antigenic trisaccharide A analogue-protein conjugate.
In some embodiments, when the blood group antigenic trisaccharide A analogue is a type A2, a conjugation ratio of the blood group antigenic trisaccharide A analogue to the keyhole limpet hemocyanin is 10:1-80:1; and when the blood group antigenic trisaccharide A analogue is a type A3 or a type A4, a conjugation ratio of the blood group antigenic trisaccharide A analogue to the keyhole limpet hemocyanin is 10:1-80:1.
In some embodiments, when the blood group antigenic trisaccharide A analogue is the type A2, a conjugation ratio of the blood group antigenic trisaccharide A analogue to the keyhole limpet hemocyanin is 40:1.
In some embodiments, when the blood group antigenic trisaccharide A analogue is the type A2, a conjugation ratio of the blood group antigenic trisaccharide A analogue to the keyhole limpet hemocyanin is 10:1-80:1; and when the blood group antigenic trisaccharide A analogue is the type A3 or the type A4, a conjugation ratio of the blood group antigenic trisaccharide A analogue to the bovine serum albumin is 10:1 or 40:1-80:1.
In some embodiments, when the blood group antigenic trisaccharide A analogue is the type A2, a conjugation ratio of the blood group antigenic trisaccharide A analogue to the bovine serum albumin is 40:1
In some embodiments, the blood group antibody detection reagent is used for immunochromatographic detection, optical density detection and column agglutination detection.
In some embodiments, the blood group antibody detection reagent is used for the immunochromatographic detection; and when the blood group antigenic trisaccharide A analogue is the type A3 or the type A4, a conjugation ratio of the blood group antigenic trisaccharide A analogue to the keyhole limpet hemocyanin is 10:1 or 40:1-80:1.
The present invention also provides an immunochromatographic detection kit, comprising a detection card, and the detection card uses a nitrocellulose membrane; the detection card is coated with a conjugate of a blood group antigenic trisaccharide B analogue to a keyhole limpet hemocyanin or a bovine serum albumin, for use in detecting a blood group antibody in a serum sample; when the blood group antigenic trisaccharide B analogue is a type B2, a conjugation ratio of the blood group antigenic trisaccharide B analogue to the keyhole limpet hemocyanin is 5:1-40:1, and a conjugation ratio of the blood group antigenic trisaccharide B analogue to the bovine serum albumin is 20:1; when the blood group antigenic trisaccharide B analogue is a type B1, a type B3 or a type B4, a conjugation ratio of the blood group antigenic trisaccharide B analogue to the keyhole limpet hemocyanin is 40:1.
In some embodiments, the detection card is further coated with a conjugate of a blood group antigenic trisaccharide A analogue to the keyhole limpet hemocyanin or the bovine serum albumin.
In some embodiments, when the blood group antigenic trisaccharide A analogue is a type A2, a conjugation ratio of the blood group antigenic trisaccharide A analogue to the keyhole limpet hemocyanin is 10:1-80:1; and when the blood group antigenic trisaccharide A analogue is a type A3 or a type A4, a conjugation ratio of the blood group antigenic trisaccharide A analogue to the keyhole limpet hemocyanin is 10:1 or 40:1-80:1.
In some embodiments, when the blood group antigenic trisaccharide A analogue is the type A2, a conjugation ratio of the blood group antigenic trisaccharide A analogue to the bovine serum albumin is 10:1-80:1; and when the blood group antigenic trisaccharide A analogue is the type A3 or the type A4, a conjugation ratio of the blood group antigenic trisaccharide A analogue to the bovine serum albumin is 10:1 or 40:1-80:1.
The present invention also provides a column agglutination kit, wherein comprising a reverse ABO grouping detection card and a blood group antigenic trisaccharide analogue-protein conjugate, and the blood group antigenic trisaccharide analogue-protein conjugate includes a conjugate of a blood group antigenic trisaccharide B analogue to a keyhole limpet hemocyanin or a bovine serum albumin; when the blood group antigenic trisaccharide B analogue is a type B2, a conjugation ratio of the blood group antigenic trisaccharide B analogue to the keyhole limpet hemocyanin is 10:1-40:1, and a conjugation ratio of the blood group antigenic trisaccharide B analogue to the bovine serum albumin is 20:1; when the blood group antigenic trisaccharide B analogue is a type B1, a type B3 or a type B4, a conjugation ratio of the blood group antigenic trisaccharide B analogue to the keyhole limpet hemocyanin is 40:1.
In some embodiments, the blood group antigenic trisaccharide analogue-protein conjugate further includes a conjugate of a blood group antigenic trisaccharide A analogue to the keyhole limpet hemocyanin or the bovine serum albumin; when the blood group antigenic trisaccharide A analogue is a type A2, a conjugation ratio of the blood group antigenic trisaccharide A analogue to the keyhole limpet hemocyanin or the bovine serum albumin is 10:1-80:1; when the blood group antigenic trisaccharide A analogue is a type A3 or a type A4, a conjugation ratio of the blood group antigenic trisaccharide A analogue to the keyhole limpet hemocyanin is 10:1-80:1, and a conjugation ratio of the blood group antigenic trisaccharide A analogue to the bovine serum albumin is 10:1 or 40:1-80:1
To make the embodiments of the present invention or the technical solutions in the prior art clearer, the drawings required to be used in the description of the embodiments or the prior art will be briefly introduced below. It is obvious that the drawings described below are some embodiments of the present invention, and that other drawings can be obtained from these drawings for those of ordinary skill in the art without making inventive effort.
To make the objective, the technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in combination with drawings. It is obvious that the described embodiments are some of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making inventive effort shall belong to the protection scope of the present invention.
As used herein, the term “about”, typically means+/−5% of the stated value, more typically +/−4% of the stated value, more typically +/−3% of the stated value, more typically, +/−2% of the stated value, even more typically +/−1% of the stated value, and even more typically +/−0.5% of the stated value.
Throughout this application, embodiments of this invention may be presented with reference to a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as “from 1 to 6” should be considered to have specifically disclosed subranges such as “from 1 to 3”, “from 1 to 4”, “from 1 to 5”, “from 2 to 4”, “from 2 to 6”, “from 3 to 6”, etc.; as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.
The “blood group antigenic trisaccharide A analogue” according to the present invention refers to four compounds with basic chemical formulas as shown in chemical formulas A1-A4 and derivatives thereof, which are a type I antigenic A compound (chemical formula A1, hereinafter referred to as “A1” or “a type A1”), a type II antigenic A compound (chemical formula A2, hereinafter referred to as “A2” or “a type A2”), a type III antigenic A compound (chemical formula A3, hereinafter referred to as “A3” or “a type A3”) and a type IV antigenic A compound (chemical formula A4, hereinafter referred to as “A4” or “a type A4”), respectively.
The “blood group antigenic trisaccharide B analogue” according to the present invention refers to four compounds with basic chemical formulas as shown in chemical formulas B1-B4 and derivatives thereof, which are a type I antigenic B compound (chemical formula B1, hereinafter referred to as “B1” or “a type B1”), a type II antigenic B compound (chemical formula B2, hereinafter referred to as “B2” or “a type B2”), a type III antigenic B compound (chemical formula B3, hereinafter referred to as “B3” or “a type B3”) and a type IV antigenic B compound (chemical formula B4, hereinafter referred to as “B4” or “a type B4”), respectively.
The “blood group antigenic trisaccharide analogue-protein conjugate” according to the present invention refers to a protein conjugate formed by conjugation of the above blood group antigenic trisaccharide A analogue to a BSA or a KLH (hereinafter referred to as “A-BSA” and “A-KLH”), and a protein conjugate formed by conjugation of the above blood group antigenic trisaccharide B analogue to a BSA or a KLH (hereinafter referred to as “B-BSA” and “B-KLH”).
In some embodiments, according to a modular assembly strategy method from the Bovin research group (Drouillar S, et al., Large-scale synthesis of H-antigen oligosaccharides by expressing helicobacter pyloria1,2-fucosyltransferase in metabolically engineered Escherichia coli cells [J]. Angew Chem, 2006, 118 (11): 1810-1812), two target sugar building blocks are synthesized first, and then a target sugar chain is synthesized by glycosylation. Main reaction steps are shown as follows:
Then terminal site of the target sugar chain generated by the above method undergo an addition reaction with butyrylamide connected with a carboxyl group to generate the antigenic trisaccharide A analogue of the present invention, four types (A1-A4) in total, with chemical structure formulas as shown in chemical formulas A1-A4. Finally, a linear linker arm with low immunogenicity, good reactivity and a high conjugation ratio is used to conjugate the blood group antigenic trisaccharide A analogue to an amino group on a lysine residue of the BSA or the KLH (for example, a section of alkane chain connected with an azide group is pre-loaded on a starting substrate during synthesis of the sugar chain, as the linker arm, and then a reagent that make both ends of the linker arm form activated esters is used to achieve the conjugation of the blood group antigenic trisaccharide analogue to a carrier protein), thereby synthesizing the blood group antigenic trisaccharide A analogue-protein conjugates (A1-BSA, A2-BSA, A3-BSA, A4-BSA; A1-KLH, A2-KLH, A3-KLH, A4-KLH) of the present invention with chemical formulas thereof shown as follows:
First, four disaccharide precursors are synthesized with a strategy of chemically introducing a linker arm comprising an azide group at reducing ends of starting monosaccharides (GlcNAc, GlaNAc) and then taking the chemically synthesized GlcNAcfProN3, GalNAcaProN3 and GalNAcfProN3 monosaccharides as acceptors to synthesize four type precursors by one-pot multienzyme. Chemical formulas thereof are as follows:
Disaccharide precursor type I of the blood group antigenic trisaccharide B analogue:
Disaccharide precursor type II of the blood group antigenic trisaccharide B analogue:
Disaccharide precursor type III of the blood group antigenic trisaccharide B analogue:
Disaccharide precursor type IV of the blood group antigenic trisaccharide B analogue:
Then, an α1-3 galactosyltransferase GTB is introduced at non-reducing ends of the above four synthesized disaccharide precursors to synthesize four blood group antigenic trisaccharide B analogues B1-B4 (molecular structures as shown in chemical formulas B1-B4), with specific synthesis routes as shown in
Finally, a linear linker arm with low immunogenicity, good reactivity and a high conjugation ratio is used to conjugate the blood group antigenic trisaccharide B analogues (B1-B4) to an amino group on a lysine residue of the BSA or the KLH (for example, a section of alkane chain connected with an azide group is pre-loaded on a starting substrate during synthesis of the sugar chain, as the linker arm, and then a reagent that make both ends of the linker arm form activated esters is used to achieve the conjugation of the blood group antigenic trisaccharide analogue to a carrier protein), thereby synthesizing the blood group antigenic trisaccharide B analogue-protein conjugates (B1-BSA, B2-BSA, B3-BSA, B4-BSA; B1-KLH, B2-KLH, B3-KLH. B4-KLH) of the present invention with chemical formulas shown as follows:
Qualitative Verification of the Blood Group Antigenic Trisaccharide Analogue-Protein Conjugate (Antigen Immobilization and Immunochromatography)
In order to investigate whether the blood group antigenic trisaccharide analogue-protein conjugates synthesized by the present invention can be used for simple and rapid qualitative blood grouping, the antigen immobilization and immunochromatography are used to perform verification in the present invention. In order to detect antibodies A and B in the serum, a detection card assembled from a Sartorius nitrocellulose (NC) membrane CN140 is used (see
During detection, a sample was added from a sample hole (labeled as S on the detection card). The blood group antibody A or B comprised in the sample could be bound with the colloidal gold-labeled anti-human u chain antibody to form a complex and chromatograph the complex on the NC membrane. When the complex was chromatographed to the T line, the blood group antibody A or B was specifically bound with the corresponding blood group antigenic trisaccharide A analogue-protein conjugate or blood group antigenic trisaccharide B analogue-protein conjugate to form a colored line that was visible with naked eyes (that is, the blood group antibody A was bound with an artificially synthesized antigen A, and the blood group antibody B was bound with an artificially synthesized antigen B). If there was no corresponding antibody A or B in the sample, the complex could not be formed and the color could not be visible at the T line. Based on this, when the sample comprised the antibody A and did not comprise the antibody B, the sample was group A blood. When the sample comprised the antibody B and did not comprise the antibody A, the sample was group B blood. When the sample comprised neither the antibody A nor the antibody B, the sample was group AB blood. When the sample comprised both the antibody A and the antibody B, the sample was group O blood. The sample was first chromatographed to the T line and then to the C line. The C line should be visible when all samples were detected, otherwise the experiment was invalid.
For the detection card in the present application, the detection card coated with the blood group antigenic trisaccharide A analogue-protein conjugates (A-BSA, A-KLH) is referred to as a detection card A in the present invention. The detection card coated with the blood group antigenic trisaccharide B analogue-protein conjugates (B-BSA, B-KLH) is referred to as a detection card B in the present invention.
1 μl of a standard blood group antibody A (Millipore, batch No.: JHE2103 and catalog No.: JH-1L-BK) was added onto each detection card A, respectively, and then 80 μl of a sample diluent (0.01M PBS) was added, to observe the color development results at the C line and the T line with naked eyes after standing for about 15 min-20 min, and photograph and record.
1 μl of a standard blood group antibody B (Millipore, batch No.: JMC2103 and catalog No.: JM-1L-BK) was added onto each detection card B, respectively, then 80 μl of the sample diluent (0.01M PBS) was added, to observe the color development results at the C line and the T line with naked eyes after standing for about 15 min-20 min, and photograph and record.
The above detection results were shown in
The above detection results showed that for the blood group antigenic trisaccharide B analogue, the color could be effectively developed at the Tline (visible with naked eyes) after the type B2 was conjugated to the BSA or the KLH. However, the color development effect of B2-BSA was obvious only when a conjugation ratio was 20:1, while B2-KLH showed a better color development effect in a wider conjugation ratio range (from 5:1 to 40:1). In addition, when the conjugation ratio of B-KLH was 40:1, color development effects of B1-KLH, B3-KLH and B4-KLH could also be visible with naked eyes. For the blood group antigenic trisaccharide A analogue, whether A2-A4 were conjugated to the BSA or the KLH, the formed blood group antigenic trisaccharide protein conjugates could effectively develop color at the T line (conjugation ratios: 10:1, 40:1, 60:1, 80:1). However, when the conjugation ratios of A-BSA and A-KLH were 20:1, only A2-BSA/A2-KLH could effectively develop color, and neither of A3-BSA/A3-KLH and A4-BSA/A4-KLH could effectively develop color. Moreover, whether A1 was conjugated to the BSA or the KLH, the color could not be effectively developed at the conjugation ratios tested in the present invention.
The above experimental results showed that after a specific blood group antigenic trisaccharide analogue was conjugated to a specific protein (for example, B2-KLH, A2-BSA, A2-KLH), or at a specific conjugation ratio (20:1 (B2-BSA); 40:1 (B1-KLH, B3-KLH, B4-KLH); 10:1, 40:1-80:1 (A3-BSA, A4-BSA, A3-KLH, A4-KLH)), when the standard blood group antibodies were detected, the color could be effectively developed at the T line and was visible with naked eyes, which proved that these blood group antigenic trisaccharide analogues could be stably and effectively immobilized on the NC membrane or other types of solid-phase media (for example, ELISA plates, various materials of microspheres or magnetic beads) after protein conjugation, and could effectively and specifically capture the corresponding blood group antibodies. Therefore, the blood group antigenic trisaccharide analogues can be used for rapid and easy qualitative detection of the blood group antibodies (for example, due to visibility with naked eyes, the results can be read by ordinary people), so that blood grouping can be completed at home or in small clinics.
For those skilled in the art, the blood group antigenic trisaccharide analogue-protein conjugates of the present invention can also be used for experimental systems using other labeling methods (for example, enzyme labeling, fluorescence labeling or other illuminant labeling). Furthermore, in addition to labeling the antibodies, the blood group antigenic trisaccharide analogue-protein conjugates can also be labeled by different labeling methods, and used for various heterogeneous or homogeneous detection according to actual needs.
Main experiment reagents used in the experiment included latex beads (125 μL of the latex beads, labeling a total of 0.1 mg of the antigen) and a reagent R1 (1 g BSA, 0.24 g Tris, 0.1 g PC300, 5 g PEG6000, 100 mL of water, pH 8.5).
The loading method of the experiment was as follows: first standard antibodies A and B (Millipore, batch No.: JHE2103 and catalog No.: JH-1L-BK; Millipore, batch No.: JMC2103 and catalog No.: JM-1L-BK) were diluted with R1 by 100 times to obtain the diluted standard antibodies A and B with a volume of 200 μL, and then 200 μL of a reagent R2 (that is, the above latex beads were diluted with TBS by 100 times) was added to obtain a total of 400 μL of the sample to be detected. In the experiment, a detection wavelength was 340 nm.
The above experimental results were summarized in the following table:
The above experimental results showed that after the antigen B used in the present invention was conjugated to the KLH, regardless of the type from B1-B4, and regardless of the conjugation ratio to the KLH in a range of 5:1-40:1, the OD value (greater than or equal to 0.334) of the antigen B bound with the antibody B was apparently higher than the OD value (the highest OD value only could reach 0.261) of the antigen B bound with the antibody A, and the P/N value (OD value of positive serum/OD value of negative serum) could reach 1.4 or more, that is, the antigen B used in the present invention could well distinguish the antibodies A and B in the detection of the blood group antibodies and had better specificity. It was worth noting that for B1-KLH, B3-KLH and B4-KLH, when the conjugation ratio was 40:1, the P/N value reached the maximum, that is, the antigen B could distinguish the antibodies A and B most. The P/N value of B2-KLH was relatively high in the conjugation ratio range (5:1-40:1) used in the present invention, and especially when the conjugation ratio was 20:1, the P/N value reached the maximum, up to 2.459.
In order to further verify the detection effect of the blood group antigenic trisaccharide B analogue-protein conjugate (B-KLH) synthesized by the present invention when the antibody concentration was lower, the standard antibodies were diluted by 200 times in the experiment. Main experiment reagents used in the experiment included latex beads (125 μL of the latex beads, labeling a total of 0.1 mg of the antigen) and the reagent R1 (1 g BSA, 0.24 g Tris, 0.1 g PC300, 5 g PEG6000, 100 mL of water, pH 8.5). The loading method of the experiment was as follows: standard antibodies A and B (Millipore, batch No.: JHE2103 and catalog No.: JH-1L-BK; Millipore, batch No.: JMC2103 and catalog No.: JM-1L-BK) were diluted with R1 by 200 times to obtain the diluted standard antibodies with a volume of 200 μL, and then 200 μL of the reagent R2 (that is, the above latex beads were diluted with TBS by 200 times) was added to obtain a total of 400 μL of the sample to be detected. In the experiment, a detection wavelength was 340 nm.
The above experimental results were summarized in the following table:
The above experimental results showed that even if the standard antibodies were diluted by 200 times, for the antigen B used in the present invention, regardless of the type from B1-B4, and regardless of the conjugation ratio to the KLH in a range of 5:1-40:1, the OD value (greater than or equal to 0.300) of the antigen B bound with the antibody B was apparently higher than the OD value (the highest OD value only could reach 0.261) of the antigen B bound with the antibody A, and the P/N value could almost reach 1.3 or more (except for B1-KLH and B3-KLH when the conjugation ratio was 5:1). In other words, even if the antibody concentration was lower, the antigen B used in the present invention could well distinguish the antibodies A and B in the detection of the blood group antibodies.
Main experiment reagents used in the experiment included latex beads (125 μL of the latex beads, labeling a total of 0.1 mg of the antigen) and the reagent R1 (1 g BSA, 0.24 g Tris, 0.1 g PC300, 5 g PEG6000, 100 mL of water, pH 8.5).
The loading method of the experiment was as follows: standard antibodies A and B (Millipore, batch No.: JHE2103 and catalog No.: JH-1L-BK; Millipore, batch No.: JMC2103 and catalog No.: JM-1L-BK) were diluted with R1 by 100 times to obtain the diluted standard antibodies with a volume of 200 μL, and then 200 μL of the reagent R2 (that is, the above latex beads were diluted with TBS by 100 times) was added to obtain a total of 400 μL of the sample to be detected. In the experiment, a detection wavelength was 340 nm.
The above experimental results were summarized in the following table:
The above experimental results showed that for the antigen B used in the present invention, regardless of the type from B1-B4, and regardless of the conjugation ratio to the BSA in a range of 5:1-40:1, although there was a difference between the OD value of the antigen B bound with the antibody B and the OD value of the antigen B bound with the antibody A, the difference was not as good as the difference between the OD values when the antigen B was conjugated to the KLH to identify the antibodies A and B. The P/N value in multiple sets of data was in a range of 1.231-1.678. The above results proved that the conjugate of the blood group antigenic trisaccharide B (B1-B4) analogue to the BSA could also detect the antibody B and distinguish the antibodies A and B in the above experiment, but the ability and effect thereof were not as good as those when the blood group antigenic trisaccharide B (B1-B4) analogue was conjugated to the KLH.
In order to further verify the detection effect of the blood group antigenic trisaccharide B analogue-protein conjugate (B-BSA) synthesized by the present invention when the antibody concentration was lower, the standard antibodies were diluted by 200 times in the experiment. Main experiment reagents used in the experiment included latex beads (125 μL of the latex beads, labeling a total of 0.1 mg of the antigen) and the reagent R1 (1 g BSA, 0.24 g Tris, 0.1 g PC300, 5 g PEG6000, 100 mL of water, pH 8.5). The loading method of the experiment was as follows: standard antibodies A and B (Millipore, batch No.: JHE2103 and catalog No.: JH-1L-BK; Millipore, batch No.: JMC2103 and catalog No.: JM-1L-BK) were diluted with R1 by 200 times to obtain the diluted standard antibodies with a volume of 200 μL, and then 200 μL of the reagent R2 (that is, the above latex beads were diluted with TBS by 200 times) was added to obtain a total of 400 μL of the sample to be detected. In the experiment, a detection wavelength was 340 nm.
The above experimental results were summarized in the following table:
The above experimental results were similar to the detection results on diluting the standard antibodies by 100 times. Regardless of the type from B1-B4, and regardless of the conjugation ratio to the BSA in a range of 5:1-40:1, although there was a difference between the OD value of the antigen B bound with the antibody B and the OD value of the antigen B bound with the antibody A, the difference was not as good as the difference between the OD values when the antigen B was conjugated to the KLH to identify the antibodies A and B. Only when B2: BSA=20:1, the P/N value could reach 1.421, and when B3: BSA=20:1, the P/N value could reach 1.394. In combination with the color development experiment on the NC membrane (Table 2a), only when B2: BSA=20:1, a chromogenic reaction could be observed on the detection card with naked eyes. The above results proved that the conjugate of the blood group antigenic trisaccharide B (B1-B4) analogue to the BSA could also detect the antibody B and distinguish the antibodies A and B to some extent, but the ability thereof was significantly inferior to that when the blood group antigenic trisaccharide B (B1-B4) analogue was conjugated to the KLH.
Main experiment reagents used in the experiment included latex beads (125 μL of the latex beads, labeling a total of 0.1 mg of the antigen) and the reagent R1 (1 g BSA, 0.24 g Tris, 0.1 g PC300, 5 g PEG6000, 100 mL of water, pH 8.5).
The loading method of the experiment was as follows: standard antibodies A and B (Millipore, batch No.: JHE2103 and catalog No.: JH-1L-BK; Millipore, batch No.: JMC2103 and catalog No.: JM-1L-BK) were diluted with R1 by 100 times to obtain the diluted standard antibodies with a volume of 200 μL, and then 200 μL of the reagent R2 (that is, the above latex beads were diluted with TBS by 100 times) was added to obtain a total of 400 μL of the sample to be detected. In the experiment, a detection wavelength was 340 nm.
The above experimental results were summarized in the following table:
The above experimental results showed that when the antigen A used in the present invention was conjugated to the BSA, regardless of the conjugation ratio of most of A2-A4 to the BSA in a range of 10:1-80:1 (except for A3: BSA=20:1, A4: BSA=20:1), the OD value (greater than or equal to 0.4) of the antigen A bound with the antibody A was higher than the OD value (the highest OD value only could reach 0.245) of the antigen A bound with the antibody B. The experiment proved that the antigens A2-A4 used in the present invention could well distinguish the antibodies A and B in the detection of the blood group antibodies, especially the distinguishing effect was the best when A2: BSA=40:1. By comparison, the A1-BSA conjugate had a poorer ability to identify the antibodies A and B, and the P/N value was only slightly higher than 1.
In order to further verify the detection effect of the blood group antigenic trisaccharide A analogue-protein conjugate (A-BSA) synthesized by the present invention when the antibody concentration was lower, the standard antibodies were diluted by 200 times in the experiment. Main experiment reagents used in the experiment included latex beads (125 μL of the latex beads, labeling a total of 0.1 mg of the antigen) and the reagent R1 (1 g BSA, 0.24 g Tris, 0.1 g PC300, 5 g PEG6000, 100 mL of water, pH 8.5). The loading method of the experiment was as follows: standard antibodies A and B (Millipore, batch No.: JHE2103 and catalog No.: JH-1L-BK; Millipore, batch No.: JMC2103 and catalog No.: JM-1L-BK) were diluted with R1 by 200 times to obtain the diluted standard antibodies with a volume of 200 μL, and then 200 μL of the reagent R2 (that is, the above latex beads were diluted with TBS by 200 times) was added to obtain a total of 400 μL of the sample to be detected. In the experiment, a detection wavelength was 340 nm.
The above experimental results were summarized in the following table:
The above experimental results showed that even if the standard samples were diluted by 200 times and the antibody concentration was low, when the antigens A2-A4 used in the present invention were conjugated to the BSA, regardless of the conjugation ratio to the BSA in a range of 10:1-80:1 (except for A3: BSA=20:1, A4: BSA=20:1), the P/N value was relatively high, that is, the antigens A2-A4 could still distinguish the antibodies A and B well in the detection of the blood group antibodies, especially the distinguishing effect was the best when A2: BSA=40:1. By comparison, the A1-BSA conjugate had a poorer ability to identify the antibodies A and B, and the P/N value was only slightly higher than 1.
Main experiment reagents used in the experiment included latex beads (125 μL of the latex beads, labeling a total of 0.1 mg of the antigen) and the reagent R1 (1 g BSA, 0.24 g Tris, 0.1 g PC300, 5 g PEG6000, 100 mL of water, pH 8.5).
The loading method of the experiment was as follows: standard antibodies A and B (Millipore, batch No.: JHE2103 and catalog No.: JH-1L-BK; Millipore, batch No.: JMC2103 and catalog No.: JM-1L-BK) were diluted with R1 by 100 times to obtain the diluted standard antibodies with a volume of 200 μL, and then 200 μL of the reagent R2 (that is, the above latex beads were diluted with TBS by 100 times) was added to obtain a total of 400 μL of the sample to be detected. In the experiment, a detection wavelength was 340 nm.
The above experimental results were summarized in the following table:
The above experimental results showed that when the antigen A used in the present invention was conjugated to the KLH, regardless of the conjugation ratio of most of A2-A4 to the KLH in a range of 10:1-80:1, the OD value (greater than or equal to 0.4) of the antigen A bound with the antibody A was higher than the OD value (the highest OD value only could reach 0.293) of the antigen A bound with the antibody B. The experiment proved that the antigens A2-A4 used in the present invention could well distinguish the antibodies A and B in the detection of the blood group antibodies, especially the distinguishing effect was the best when A2: KLH=40:1. By comparison, the A1-KLH conjugate had a poorer ability to identify the antibodies A and B, and the P/N value was only slightly higher than 1.
In order to further verify the detection effect of the blood group antigenic trisaccharide A analogue-protein conjugate (A-KLH) synthesized by the present invention when the antibody concentration was lower, the standard antibodies were diluted by 200 times in the experiment. Main experiment reagents used in the experiment included latex beads (125 μL of the latex beads, labeling a total of 0.1 mg of the antigen) and the reagent R1 (1 g BSA, 0.24 g Tris, 0.1 g PC300, 5 g PEG6000, 100 mL of water, pH 8.5). The loading method of the experiment was as follows: standard antibodies A and B (Millipore, batch No.: JHE2103 and catalog No.: JH-1L-BK; Millipore, batch No.: JMC2103 and catalog No.: JM-1L-BK) were diluted with R1 by 200 times to obtain the diluted standard antibodies with a volume of 200 μL, and then 200 μL of the reagent R2 (that is, the above latex beads were diluted with TBS by 200 times) was added to obtain a total of 400 μL of the sample to be detected. In the experiment, a detection wavelength was 340 nm.
The above experimental results were summarized in the following table:
The above experimental results showed that even if the standard samples were diluted by 200 times, when the antigens A2-A4 used in the present invention were conjugated to the KLH, regardless of the conjugation ratio to the KLH in a range of 10:1-80:1, the P/N value was relatively higher, that is, the antigens A2-A4 could still distinguish the antibodies A and B well in the detection of the blood group antibodies, especially the distinguishing effect was the best when A2: KLH=40:1. By comparison, the A1-KLH conjugate had a poorer ability to identify the antibodies A and B, and the P/N value was only slightly higher than 1.
A reverse human ABO grouping detection card (column agglutination) was used in the embodiment to perform a neutralization experiment, that is, first an artificial antigen was used to neutralize a certain amount of an antibody, and then indicator cells were added to check whether there was still the antibody that had not yet been neutralized by the artificial antigen. If the artificial antigen had strong specificity and high efficiency when bound with the antibody, the antibody could be fully neutralized by the artificial antigen, and when the indicator cells (corresponding to the antibody) were added, there was no antibody that could react with surface antigens of the indicator cells, so that the experimental result was negative (without agglutination). Conversely, if the artificial antigen had weak specificity and low efficiency when bound with the antibody, the antibody could not be fully neutralized by the artificial antigen, and when the indicator cells (corresponding to the antibody) were added, there was still the antibody that could react with surface antigens of the indicator cells, so that the experimental result was positive (with agglutination). Through the above experimental design, the performance of the reaction between the artificially synthesized antigens (that is, the blood group antigenic trisaccharide B analogue-protein conjugate and the blood group antigenic trisaccharide A analogue-protein conjugate according to the present invention) and the antibodies could be effectively verified, that is, whether the artificially synthesized antigen had good specificity in identifying its corresponding antibody.
The information of the standard antibody A used in the experiment is: Millipore, batch No.: JHE2103 and catalog No.: JH-1L-BK. The information of the standard antibody B used in the experiment is: Millipore, batch No.: JMC2103 and catalog No.: JM-1L-BK.
Experimental results: Table 5a showed that the antigen B (B1-B4) conjugated to the BSA had generally weak neutralization ability for the antibody B. By comparison within B-BSA, B2-BSA was better (when the antibody B was diluted by 10000 times, the experimental results were negative at all conjugation ratios), especially the neutralization ability was relatively stronger when B2: BSA=20:1 (the antibody B could be fully neutralized when diluted by 1000 times). When the antibody B was diluted by 1000 times, B1-BSA and B3-BSA showed better neutralization abilities for the antibody B when the conjugation ratio was 20:1 when compared with the same type of antigens at other conjugation ratios. B4-BSA showed better neutralization ability for the antibody B when the conjugation ratio was 40:1 when compared with the same type of antigens at other conjugation ratios. Table 5b was a control experiment using the antibody A, in which the antigen B (B1-B4) conjugated to the BSA should neither perform a neutralization reaction nor react with the indicator cells B, so that the experimental results were all negative, proving that the experimental system operated normally.
Experimental results: Table 5c showed that B2-KLH had relatively better neutralization ability for the antibody B when the antigen B (B1-B4) was conjugated to the KLH, especially the neutralization ability was the strongest when B2: KLH=20:1 (even in a high concentration environment where the antibody B was only diluted by 10 times, the antibody B could still be fully neutralized when B2: KLH=20:1). B2-KLH also showed good specificity when B2: KLH=40:1, and in a relatively high concentration environment where the antibody B was diluted by 100 times, the antibody B could still be fully neutralized. B1-KLH, B3-KLH and B4-KLH showed better neutralization ability for the antibody B when the conjugation ratio was 40:1 when compared with the same type of antigens at other conjugation ratios, and in an environment where the antibody B was diluted by 1000 times, the antibody B could be fully neutralized. Table 5d was a control experiment using the antibody A, in which the antigen B (B1-B4) conjugated to the KLH should neither perform a neutralization reaction nor react with the indicator cells B, so that the experimental result were all negative, proving that the experimental system operated normally.
Table 6a showed that A2-BSA had better neutralization ability for the antibody A when the antigen A (A1-A4) was conjugated to the BSA, especially the neutralization ability was the strongest when A2: BSA=40:1 (even in a high concentration environment where the antibody A was only diluted by 10 times, the antibody A could still be fully neutralized when A2: BSA=40:1). A2-BSA also showed good specificity at other conjugation ratios (10:1-20:1, 60:1-80:1), and in a relatively high concentration environment where the antibody A was diluted by 100 times, the antibody A could still be fully neutralized. A3-BSA and A4-BSA showed better neutralization ability for the antibody A when the conjugation ratio was in a range of 40:1-80:1 when compared with the same type of antigens at other conjugation ratios, and in an environment where the antibody A was diluted by 1000 times, the antibody A could be fully neutralized. Table 6b was a control experiment using the antibody B, in which the antigen A (A1-A4) conjugated to the KLH should neither perform a neutralization reaction nor react with the indicator cells A, so that the experimental results were all negative, proving that the experimental system operated normally.
Experimental results: Table 6c showed that A2-KLH had better neutralization ability for the antibody A when the antigen A (A1-A4) was conjugated to the KLH, especially the neutralization ability was the strongest when A2: KLH=40:1 (even in a high concentration environment where the antibody A was only diluted by 10 times, the antibody A could still be fully neutralized when A2: KLH=40:1). A2-KLH also showed good specificity at other conjugation ratios (10:1-20:1, 60:1-80:1), and in a relatively high concentration environment where the antibody A was diluted by 100 times, the antibody A could still be fully neutralized. A3-KLH and A4-KLH also showed certain neutralization ability for the antibody A at various conjugation ratios (10:1-80:1), and in an environment where the antibody A was diluted by 1000 times, the antibody A could be fully neutralized. Table 6d was a control experiment using the antibody B, in which the antigen A (A1-A4) conjugated to the KLH should neither perform a neutralization reaction nor react with the indicator cells A, so that the experimental results were all negative, proving that the experimental system operated normally.
In the above experiments, the blood group antigenic trisaccharide B analogue-protein conjugates with obvious or relatively obvious experimental effects were summarized in Table 7a. The blood group antigenic trisaccharide A analogue-protein conjugates with obvious or relatively obvious experimental effects were summarized in Table 7b.
The embodiments of the present invention are described above with reference to the accompanying drawings, but the present invention is not limited to the aforementioned specific embodiments. The aforementioned embodiments are merely 5 illustrative and not limiting. For those of ordinary skill in the art, many forms can be made under the teaching of present invention without departing from the spirit of the present invention and the scope of the claims, all of which shall fall within the protection scope of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202211269823.5 | Oct 2022 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2022/136512 | 12/5/2022 | WO |
