Selective and polyclonal induction of high levels of lambda light chain-bearing immunoglobulins in BALB/c and SJL mice.

Polyclonal B cell activation is V gene independent and consequently results in the unselected expression of both V lambda and V kappa genes. In an attempt to selectively and polyclonally trigger lambda light chain-bearing B cells, we immunized mice with low doses of lipopolysaccharide (LPS) coupled to antibodies specific for the constant region of lambda 1 chains. Analyses of the sera of treated mice revealed that LPS anti-lambda 1 selectively triggers lambda-but not kappa-bearing B cells to high rate Ig secretion. Surprisingly, immunized SJL mice (rlo lambda 1 phenotype) mounted a lambda + response comparable to that detected in mice with the r + lambda 1 phenotype. Because we could definitively establish that the majority of the induced antibodies belong the lambda 1 subtype, our results have strong implications both for the study of the repertoire of lambda 1-bearing B cells and for our understanding of the functional mechanism(s) by which the r lambda 1 locus acts.