Abstract:
Strong anti glycolipid IgG responses can occur in humans and animals, but contrary to anti protein responses and anti
glycoprotein responses, the exact mechanism of induction is unknown. We have previously shown that experimental
immunization with the glycolipid glucose monomycolate (GMM) causes the development of specific T cell responses, but
not of anti GMM antibodies. However, cattle naturally infected with Mycobacterium avium ssp. paratuberculosis produce high
levels of anti GMM IgG. In the present study, we tested whether vaccination with GMM conjugated to a protein mimics
natural infection in its capacity to induce the production of antibodies against GMM. Cattle were immunized (n = 5 per group)
with GMM conjugated to a protein, or GMM and protein non-conjugated and administered at contralateral locations, or
carrier only. Although immunization with the GMM-protein conjugate vaccine and the non-conjugated vaccine induced
protein specific antibody responses, GMM specific antibodies were not detected in either of the groups. In conclusion, the
generation of isotype-switched anti lipid antibodies appears to require more than providing peptide epitopes for T helper cells
to support glycolipid specific B cells in antibody production.
