Staphylococcal peptidoglycan: T-cell-dependent mitogen and relatively T-cell-independent polyclonal B-cell activator of human lymphocytes.
Staphylococcal cell wall products have been widely examined as probes for dissection of in vitro human immune responses. Mitogenic and polyclonal B-cell-activating properties have been attributed to intact cell walls or the protein A constituent thereof. We now report that staphylococcal peptidoglycan (PG), the major cell wall constituent, is not only a potent mitogen but also a polyclonal B-cell activator for human peripheral blood mononuclear cells (PBM). PG-induced proliferative responses of human PBM were comparable to that observed in pokeweed mitogen-stimulated cultures. As was true for pokeweed mitogen, PG-induced proliferation required the presence of T-cell help. Cultures of human PBM with PG also resulted in B-cell differentiation as reflected by an increase in numbers of immunoglobulin-secreting cells in stimulated cultures. In contrast to the proliferative response, PG-induced B-cell differentiation was relatively T-cell independent. This point became apparent when B-cell fractions were partially depleted of excessive numbers of monocytes before culture. Also, B-cell proliferation did not appear to be a major prerequisite for PG-induced B-cell differentiation responses. These data indicate that PG is a potent T-cell-dependent mitogen and relatively T-cell-independent polyclonal B-cell activator of human lymphocytes.
D001402:B-Lymphocytes / Q000187:drug effects*; D002454:Cell Differentiation / Q000187:drug effects; D006801:Humans; D007136:Immunoglobulins / Q000378:metabolism; D008213:Lymphocyte Activation / Q000187:drug effects*; D008934:Mitogens / Q000494:pharmacology*; D010457:Peptidoglycan / Q000494:pharmacology*; D013210:Staphylococcus / Q000032:analysis*; D013601:T-Lymphocytes / Q000276:immunology*
D007136:Immunoglobulins; D008934:Mitogens; D010457:Peptidoglycan