Apoptosis induction by glucuronoxylomannan of Cryptococcus neoformans

L. S. CHIAPELLO, M. P. AOKI, H. R. RUBINSTEIN & D. T. MASIH

MEDICAL MYCOLOGY

Taylor and Francis

Año: 2003 vol. 41 p. 347 - 353

1369-3786

We studied the ability of glucuronoxylomannan (GXM), the major constituent of Cryptococcus neoformans capsular polysaccharide, to induce apoptosis in lymphocytes from normal rats. Spleen mononuclear cells (Smc) from normal rats treated with GXM for 24 h exhibited, in comparison with controls, an increased hypodiploidy in the DNA profile after staining with propidium iodide, as well as increased ladder-type DNA fragmentation in agarose gel electrophoresis and a high number of positive cells in the terminal deoxynucleotidyl transferase biotindUTP nick end labeling (TUNEL) reaction. Furthermore, increased hypodiploidy in the DNA profile was also observed in Smc expressing T-cell receptor (TCR/). We also studied the induction of apoptosis in lungs and spleens from rats in the immunosuppressor period of disseminated cryptococcosis. TUNEL labeling of lungs and spleens from rats obtained 14 days after infection with C. neoformanscapsular polysaccharide, to induce apoptosis in lymphocytes from normal rats. Spleen mononuclear cells (Smc) from normal rats treated with GXM for 24 h exhibited, in comparison with controls, an increased hypodiploidy in the DNA profile after staining with propidium iodide, as well as increased ladder-type DNA fragmentation in agarose gel electrophoresis and a high number of positive cells in the terminal deoxynucleotidyl transferase biotindUTP nick end labeling (TUNEL) reaction. Furthermore, increased hypodiploidy in the DNA profile was also observed in Smc expressing T-cell receptor (TCR/). We also studied the induction of apoptosis in lungs and spleens from rats in the immunosuppressor period of disseminated cryptococcosis. TUNEL labeling of lungs and spleens from rats obtained 14 days after infection with C. neoformans/). We also studied the induction of apoptosis in lungs and spleens from rats in the immunosuppressor period of disseminated cryptococcosis. TUNEL labeling of lungs and spleens from rats obtained 14 days after infection with C. neoformansC. neoformans showed a large number of apoptotic cells. Our results provide strong cytometric, molecular and morphological evidence that apoptosis could be a previously unrecognized immunosuppressive property of GXM in vitro. This programmed cell death may be involved in the immunosuppression observed during C. neoformansin vitro. This programmed cell death may be involved in the immunosuppression observed during C. neoformansC. neoformans infection.