Hamsters immunized with N-p-tosyl-
L-lysine-chloromethyl
ketone TLCK-treated L. brasiliensis brasiliensis (LB) from culture, infected with LB amastigotes presented: a gradual increase in T and B cell responsiveness to
mitogens by lymph node lymphocytes, and an increased response to
concanavalin A with no changes for
dextran sulphate and
pokeweed mitogen in splenocytes. Absence of parasites in lymph nodes after 6 weeks post-
infection and a nodule 4 times smaller than that of infected control animals. The nodule was undetectable after 70 days of
infection. Hamsters preimmunized with
TLCK-treated L. donovani (LD) from culture did not show suppression of the blastogenic response to
mitogens of spleen and lymph node cells after
infection with LD amastigotes and survived for more than one year, whereas infected, unimmunized animals died five months after
infection. Animals preimmunized with culture parasites (LB or LD) treated with phenyl-methyl-sulphonyl-
fluoride (PMSF) and infected with LB or LD amastigotes did not show any protective effect.