Cryptococcus neoformans glucuronoxylomannan induces macrophage apoptosis mediated by nitric oxide in a caspase-independent pathway

LAURA S. CHIAPELLO, JOSE´ L. BARONETTI, ANA P. GARRO, MARÝ´A F. SPESSO AND DIANA T. MASIH

INTERNATIONAL IMMUNOLOGY

Año: 2008 vol. 20 p. 1527 - 1527

0953-8178

p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: justify">Glucuronoxylomannan (GXM) is the major component of Cryptococcus capsular polysaccharide, which represents an essential virulence factor for this yeast. Cryptococcus neoformans infections in immunocompetent rats are associated with inducible NO synthase (iNOS) expression and nitric oxide (NO) production by macrophages. This study demonstrates in vitro and in vivo that GXM promotes iNOS expression with NO production in rat macrophages. GXM also induced macrophage apoptosis after 48 h of culture, with this phenomenon being prevented by the iNOS inhibitor, aminoguanidine. The NO-induced macrophage apoptosis triggered by GXM was dependent on interactions with CD18, Fc