Relationship between immune system and gram-negative bacteria. III. Functional analysis of human peripheral blood lymphocyte subpopulations separated by cytoadherence with Salmonella minnesota Rb.
Spontaneous adherence of bacteria to human peripheral blood mononuclear cells (PBMC) represents a useful tool for analysis of lymphocyte subsets with different functions. We have recently shown that PBMC can be divided into 2 populations based on their ability to bind Salmonella minnesota R345 (Rb) bacteria. By using these procedures, here, we provide evidence that Rb-bound and Rb-unbound PBMC populations give similar proliferative responses to phytohemagglutinin (PHA) and concanavalin A (Con A), while the pokeweed mitogen (PWM)-induced proliferative and differentiative responses are higher in the Rb-unbound than in the Rb-bound PBMC fraction. Moreover, enhanced PWM-induced responses are obtained in Rb-unbound cell cultures enriched for T4+ cells. When B (non-E rosetting) cells are cultured with purified T lymphocytes from the Rb-bound (T-Rb+) and Rb-unbound (T-Rb-) fractions, comparable PWM-induced mitogenic responses are observed. The T-Rb- population contains a higher percentage of cells expressing T4+ phenotype, and when added to B cell cultures a more elevated PWM-induced IgA, IgG and IgM synthesis is observed than in B cell cultures containing T-Rb+ cells. These results suggest that the T-Rb- fraction is enriched for T cells which help IgA, IgG and IgM responses.
D001402:B-Lymphocytes / Q000276:immunology; D003165:Complement System Proteins / Q000276:immunology; D003208:Concanavalin A / Q000494:pharmacology; D003602:Cytotoxicity, Immunologic; D006801:Humans; D007136:Immunoglobulins / Q000096:biosynthesis; D066298:In Vitro Techniques; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000276:immunology*; D008938:Mitosis; D010835:Phytohemagglutinins / Q000494:pharmacology; D011043:Pokeweed Mitogens / Q000494:pharmacology; D012475:Salmonella / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
D007136:Immunoglobulins; D010835:Phytohemagglutinins; D011043:Pokeweed Mitogens; D003208:Concanavalin A; D003165:Complement System Proteins