Inhibition of mouse lymphocyte proliferative response by glycosphingolipids from Leishmania (L.) amazonensis

The effect of a purified preparation of glycosphingolipids (GSLs) extracted from Leishmania (L.) amazonensis amastigotes on murine lymphocytes was investigated. GSLs inhibited both concanavalin A (Con A)- or lipopolysaccharide-induced [3H]thymidine uptake by normal and immunized BALB/c mouse lymph node cells. The effect of total GSLs was dose dependent. Total GSLs also suppressed the two-way mixed lymphocyte reaction of BALB/c x C57BL/6 cells and the antigen-specific response of immunized mouse cells. Six pure bands as well as a pool containing a mixture of GSLs with five to seven sugar residues separated by a combination of HPLC and preparative HPTLC were tested and shown to be inhibitors of Con A stimulation. These results suggest that parasite glycosphingolipids may play an immunologically relevant role in leishmaniasis.