This planning grant is to serologically differentiate and/or identify the factor(s) from already established interleukins, r-interferon and tissue necrosis factor. The P.I. will try to accomplish this objective through the use of monoclonal and/or polyclonal antibodies to these established factors in neutralization assays against the lysophospholipid-induced factor(s). The specific aims are to: 1) Determine the effects of monoclonal antibodies (MAbs) and /or polyclonal antibody to interleukin-l (IL-l) and IL-4 on the activation of macrophages by macrophage pro-activating factor (MPAF) derived from lyso-pc- or DDG-treated B cells. 2) Determine the effects of MAbs and/or polyclonal antibody to IL-l to IL-7 on the activation of macrophages by macrophage activating factor (MAF) derived from MPAF-sensitized T cells. 3) Determine the effect of MAb and/or polyclonal antibody to r-interferon on the activation of macrophages by MPAF and MAF. 4) Determine the effect of MAb and/or polyclonal antibody to TNfa on the activation of macrophages by MPAF and MAF.