Effect of L-alanosine on immune response.

L-alanosine is an antitumor compound which has recently entered clinical trials. Single i.p. doses of this drug inhibit antibody production to thymus-dependent and thymus-independent antigens as well as delayed hypersensitivity to SRBC in mice. Moreover, the in vitro lymphoproliferative responses of splenocytes to Concanavalin A and bacterial Lipopolysaccharides are also affected when the drug is added upon setting up the cultures. On the other hand, in vivo treatment with L-alanosine does not impair spleen natural killer (NK) activity. The results are discussed in an effort to characterize the immuno-suppressive activity of L-alanosine.