CD40, B7, and major histocompatibility complex enhance immunity.

2003 APR 2 - (NewsRx.com & NewsRx.net) -- CD40, B7, and the major histocompatibility complex play roles in the induction of enhanced immunity by cryptococcal polysaccharide-pulsed antigen-presenting cells.

"Immunization of mice with activated antigen-presenting cells (APC) pulsed ex vivo with cryptococcal capsular polysaccharide, a glucuronoxylomannan (GXM-APC) results in prolongation of survival and delayed-type hypersensitivity (DTH) responsiveness following infection with Cryptococcus neoformans (NU-2)," researchers in the United States report.

"GXM-APC has both nonspecific and GXM-specific effects that influence the immune responses that develop in mice after infection with NU-2," said Rebecca Blackstock at the University of Oklahoma. "Type 1 cytokine responses are augmented after immunization with APC alone, while GXM must be present for the vaccine to influence survival and DTH reactions. This investigation evaluated the role that major histocompatibility complex (MHC) and co-stimulatory molecules play in the non-specific and GXM-specific responses induced by GXM-APC."

"APC from CD40 knockout mice were as effective as wild-type APC for the induction of non-specific and GXM-specific responses," Blackstock found. "Blocking activity of B7-1 and B7-2 by treatment of immunized mice with monoclonal antibodies specific for these molecules just before and for 6 days following GXM-APC immunization decreased the splenic interferon-gamma response of mice subsequently infected with NU-2, but only in mice ...