Peripheral lymphoid hyperplasia and central lymphoid depletion in mice treated with a bacterial B-cell mitogen (F3'EP-Si/p90).
In order to further understand the mechanism mediating the mitogenic and immunosuppressor effects of p90, a protein produced by Streptococcus intermedius, flow cytometric studies were performed on peripheral and central lymphoid organs of mice treated with this protein. p90 induced a strong blastogenic B-cell response in the spleen and lymph nodes, followed by a slight but significant polyclonal T-cell activation. B-cell repertoire analysis indicated that polyclonal B-cell responses affected similarly both CD5+ and conventional (CD5-) B cells in the spleen. Repertoire analysis of T cells failed to reveal any preferential stimulation of the V beta T-cell receptor (V beta-TcR) families studied. Peripheral lymphoid hyperplasia was observed concomitantly with central lymphoid depletion. In the bone marrow, pre-B and B cells were profoundly depleted, with a more pronounced effect on small pre-B cells. In the thymus, double-positive (CD4+CD8+) thymocytes were preferentially eliminated, with a relative enrichment of single positive (either CD4+ or CD8+) and double-negative (CD4-CD8-) thymocytes.
Lima
M
M
Department of Immunology, Institute for Biomedical Sciences Abel Salazar, Porto, Portugal.
Portnoi
D
D
Bandeira
A
A
Arala Chaves
M
M
D000818:Animals; D015703:Antigens, CD / Q000502:physiology; D001853:Bone Marrow / Q000187:drug effects; D017252:CD3 Complex; D018956:CD5 Antigens; D005434:Flow Cytometry; D006965:Hyperplasia / Q000139:chemically induced; D007075:Immunoglobulin M / Q000096:biosynthesis; D016130:Immunophenotyping; D008198:Lymph Nodes / Q000187:drug effects / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D008212:Lymphocyte Depletion; D016131:Lymphocyte Subsets / Q000187:drug effects* / Q000276:immunology; D008221:Lymphoid Tissue / Q000187:drug effects* / Q000276:immunology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008934:Mitogens / Q000494:pharmacology*; D013154:Spleen / Q000187:drug effects / Q000276:immunology; D013950:Thymus Gland / Q000187:drug effects; D013997:Time Factors
D015703:Antigens, CD; D017252:CD3 Complex; D018956:CD5 Antigens; D007075:Immunoglobulin M; D008934:Mitogens