title: Further study on the humoral response of a highly-purified spleen-derived immunosuppressive peptide (SDIP).
abstract: Some biological properties of a highly-purified non-cytotoxic spleen-derived immunosuppressive peptide (SDIP) have been investigated. SDIP was shown to inhibit the primary anti-sheep red blood cell (SRBC) response at the last step of differentiation of the lymphocyte. In the present study we demonstrated that this response seemed to be T- and adherent spleen-cell dependent as no inhibition was noticed either in the response to TNP-LPS, a T-independent antigen, or in the response to SRBC in adherent spleen cell-depleted cultures. SDIP activity did not occur through an inhibition of splenocytes DNA synthesis since [3H]-thymidine ([3H]-TdR) incorporation was not modified in mitogen or allogenic stimulated cultures. Conversely, SDIP could act through a stimulation of a T-cell subset as a low specific increase of [3H]-TdR was noticed in cultured thymocytes.
mesh_terms: D000818:Animals; D000917:Antibody Formation; D000955:Antigens, T-Independent / Q000276:immunology; D004912:Erythrocytes / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D007075:Immunoglobulin M / Q000276:immunology; D007156:Immunologic Memory; D008213:Lymphocyte Activation / Q000187:drug effects; D008214:Lymphocytes / Q000378:metabolism; D051379:Mice; D008815:Mice, Inbred Strains; D010455:Peptides / Q000276:immunology*; D013154:Spleen / Q000166:cytology / Q000276:immunology*; D013491:Suppressor Factors, Immunologic; D013601:T-Lymphocytes / Q000276:immunology; D013936:Thymidine / Q000378:metabolism
chemical_list: D000955:Antigens, T-Independent; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D010455:Peptides; D013491:Suppressor Factors, Immunologic; C029640:spleen derived immunosuppressive peptide; D013936:Thymidine