The immune response of CBA/N mice and their F1 hybrids to 2,4,6-trinitrophenylated (TNP) antigens. I. Analysis of the response to TNP-coupled lipopolysaccharide in vivo and at the clonal level.

Plaque-forming cell (PFC) responses to 2,4,6-trinitrophenylated lipopolysaccharide (TNP-LPS) were studied in normal and immunodeficient mice. In vivo immunizations with TNP-LPS showed a 25--50% reduction in PFC responses in CBA/N mice and their (CBA/N X BALB/c)F1(NBF1) male hybrids with an X-linked immune defect of B lymphocyte differentiation. A detailed clonal analysis of the reduced responses to TNP-LPS revealed that CBA/N and NBF1 male mice with the X-linked genetic defect have fewer precursor B cells engaged in the response to TNP-LPS than the control mice. The reduction in precursor cell numbers affects selectively B cells secreting high avidity anti-TNP antibodies as determined by PFC inhibition studies.