Appearance of T lymphocyte-derived proteins specific for the immunizing antigen in serum during a humoral immune response.
Some T lymphocytes produce extracellular proteins that bind nominal antigen specifically (TABM), and these proteins exhibit potent immunoregulatory activity. We have utilized an ELISA for Ag binding by Ag-specific TABM to detect and quantitate the appearance of Ag-specific TABM in murine serum during a humoral Ir to protein Ag. The TABM response was specific for the inducing Ag, stronger and more rapid during a secondary response, and temporally distinct from the appearance of Ig. The non-Ig serum TABM were bound by mAb specific for TCR-alpha chains and isolated by affinity for Ag were Mr 110,000 polypeptides. The TABM response did not occur in scid/scid mice unless the mice were reconstituted with thymocytes and thymocyte-reconstituted scid/scid mice produced TABM, but did not produce Ig. The results suggest that soluble TABM are an Ag-specific humoral manifestation of the Ir of some T lymphocytes.
Urbanski
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M
Department of Pathology, University of Connecticut Health Center, Farmington 06030-3105.
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D000818:Animals; D000917:Antibody Formation; D015153:Blotting, Western; D002352:Carrier Proteins / Q000276:immunology* / Q000302:isolation & purification; D002846:Chromatography, Affinity; D004797:Enzyme-Linked Immunosorbent Assay; D007136:Immunoglobulins / Q000096:biosynthesis; D051379:Mice; D008807:Mice, Inbred BALB C; D016513:Mice, SCID; D009113:Muramidase / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
D002352:Carrier Proteins; D007136:Immunoglobulins; D009113:Muramidase