M. Franco et al., PARACOCCIDIOIDES-BRASILIENSIS ANTIGEN BATCHES FROM THE SAME ISOLATE SHOW IMMUNOLOGICAL AND BIOCHEMICAL DIFFERENCES, Mycopathologia, 135(1), 1996, pp. 13-19
We investigated the occurrence of antigenic and biochemical variabilit
y among Paracoccidioides brasiliensis antigen batches prepared accordi
ng to the same protocol. Initially (experiment #1), we analyzed two an
tigen lots of two human isolates (Bt1 & Bt2), cultured in two media (P
YG: bactopeptone, yeast extract, glucose; MMM: McVeigh & Morton medium
) in SDS-PAGE and in two immunological tests (imunodiffusion-ID and fo
otpad swelling test-FPT). Afterwards (experiment #2), we compared the
antigenic profile of three antigen batches from three human isolates (
Bt1, Bt2 & Bt3) by two-dimensional immunoelectrophoresis (2D-IEP) agai
nst a reference system for Il brasiliensis antigens. In experiment #1,
there were important intra- and inter-strain antigenic differences be
tween batches of the fungal isolates cultured on both media. The block
titration of the antigen batches for the immunological tests revealed
correlation between protein concentration and biological activity in
ID and no correlation in FPT. In experiment #2, the reference system f
or P. brasiliensis showed 26 antigen peaks. There were important diffe
rences between batches prepared from the same isolate and between batc
hes from different isolates. Our data suggested the occurrence of inst
ability in the synthesis of antigenic components by a same P. brasilie
nsis isolate, under controlled incubation conditions.