V. Nagabhushanam et al., Molecular and immunological characterization of Mycobacterium avium 65 kDaheat shock protein (Hsp65), IMM CELL B, 79(5), 2001, pp. 454-461
The heat shock protein Hsp65 has been characterized previously in several m
ycobacterial species. This is the first report of the complete sequence of
the coding region of the Mycobacterium avium homologue. The sequence was hi
ghly homologous to the Hsp65 of other mycobacterial species, as well as bei
ng related closely to the murine and human homologues. Recombinant Hsp65 (r
Hsp65) was expressed in Escherichia coli to high levels and the recombinant
protein tested for its immunogenicity in a murine model of M. avium infect
ion. Although mice infected with M. avium produced antibodies that reacted
with rHsp65, they showed low proliferative T-cell responses and no cytokine
production in response to the same antigen. However, immunization with rHs
p65 in the adjuvant dimethydioctadecylammonium bromide (DDA), induced T cel
ls that responded to native Hsp65 with proliferation and IFN-gamma producti
on, indicating that the recombinant and native forms of the protein were an
tigenically similar. Therefore, the findings indicate that Hsp65 is not a d
ominant T-cell antigen during M. avium infection.