Induced mouse spleen B-cell proliferation and secretion of immunoglobulin by lipid-associated membrane proteins of Mycoplasma fermentans incognitus and Mycoplasma penetrans.
Mycoplasmas have been implicated as a possible cofactor in AIDS pathogenesis. Mycoplasma fermentans and M. penetrans infect human immunodeficiency virus-positive patients at a significantly higher frequency than non-human immunodeficiency virus-infected control subjects. Various mycoplasmal membrane preparations are known to affect the functions of immune cells both in vitro and in vivo. A group of lipid-associated membrane proteins (LAMPs) extracted by Triton X-114 from mycoplasmas are major antigenic targets of human host antibody responses. In this study, LAMPs prepared from both M. fermentans and M. penetrans nonspecifically stimulated spleen cells of CBA/CaH mice to proliferate. LAMPs were also stimulatory to spleen cells from athymic mice. On the other hand, enriched splenic T cells from CBA/CaH mice with or without accessory cells responded poorly. Thus, the mitogenic effect of mycoplasmal LAMPs appeared mainly on B cells. High levels of immunoglobulin (Ig) M and low but detectable amounts of IgG were found in the supernatant of LAMP-treated splenic cell culture. M. penetrans LAMPs had a much more potent effect on murine spleen cells than did M. fermentans incognitus LAMPs in inducing both B-cell proliferation and Ig secretion. In conclusion, the mycoplasmal LAMPs contained an active component(s) with T-independent B-cell mitogenic effect.
Feng
S H
SH
Department of Infectious and Parasitic Disease Pathology, Armed Forces Institute of Pathology, Washington, D.C. 20306.
Lo
S C
SC
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D001426:Bacterial Proteins / Q000494:pharmacology*; D005260:Female; D015151:Immunoblotting; D007136:Immunoglobulins / Q000096:biosynthesis*; D008213:Lymphocyte Activation / Q000187:drug effects*; D008565:Membrane Proteins / Q000494:pharmacology*; D051379:Mice; D008808:Mice, Inbred CBA; D009174:Mycoplasma / Q000276:immunology*; D016858:Mycoplasma fermentans / Q000276:immunology*
D001426:Bacterial Proteins; D007136:Immunoglobulins; D008565:Membrane Proteins