The glycoconjugate derived from a Leishmania major receptor for macrophages is a suppressogenic, disease‐promoting antigen in murine cutaneous leishmaniasis

Lymphoid cells from genetically-susceptible BALB/c mice immunized against a glycoconjugate of the protozoan parasite, Leishmania major, promote chronic cutaneous disease in BALB/c nude mice. This cell population therefore differs from cells harvested from non-immunized BALB/c mice that are known to be potent mediators of protection against cutaneous leishmaniasis in minimally-reconstituted, syngeneic nude mice. The glycoconjugate when injected into genetically-resistant C57BL/6 mice will increase the size and persistence of cutaneous lesions. Recent studies have established that the water soluble glycoconjugate is derived from a membrane-bound glycolipid that is a receptor used by the parasite in the attachment to macrophages. This glycolipid can protectively immunize mice against cutaneous leishmaniasis. Identification of a vaccinating glycolipid antigen and a suppressogenic component derived from it will greatly facilitate analysis of disease-promoting and resistance-promoting immunity in cutaneous leishmaniasis. However, the fact that a host-protective antigen contains a disease-promoting component may militate against the immediate use of this molecular vaccine in man.