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pubmed:abstractText |
We have compared the responses of purified neonatal and adult B lymphocytes to stimulation by anti-Ig antibodies, which are functional analogues of Ag, and by Th cells. Neonatal B cells are markedly deficient in proliferative responses to anti-Ig antibodies + IL-4 or to anti-Ig conjugated to dextran, both of which induce strong proliferation of adult B cells in the absence of T lymphocytes. Anti-Ig antibodies actually inhibit the functional responses of neonatal B cells, even to polyclonal stimuli such as LPS. However, Th cells induce both proliferation and Ig secretion by neonatal B cells in the presence of Ag that bind to B cell Ig and are subsequently presented by the B cells. Thus, in neonatal B lymphocytes, cross-linking of membrane Ig in the absence of Th cells has a net inhibitory effect, and this inhibition is overcome by T cell help. These results also suggest that unresponsiveness or tolerance to thymus-independent Ag is induced in the B cells themselves, but tolerance to thymus-dependent proteins resides primarily in the T cell compartment.
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pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
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