       Document 0099
 DOCN  M9460099
 TI    Polysaccharide antigens of the capsule of Cryptococcus neoformans.
 DT    9408
 AU    Cherniak R; Sundstrom JB; Department of Chemistry, Georgia State
       University, Atlanta 30303.
 SO    Infect Immun. 1994 May;62(5):1507-12. Unique Identifier : AIDSLINE
       MED/94222507
 AB    The major significance of the capsular polysaccharide of C. neoformans
       is its role in potentiating opportunistic infections by the yeast. It
       has the ability to exert a broad spectrum of influences on the immune
       response, from activation of phagocytic cells and complement components
       of the alternative pathway, to the induction of specific antibody,
       T-suppressor cells, DTH responses, and cytokines (51). These biological
       properties along with the serotype specificities are all determined by
       the physical properties and chemical structures of the polysaccharide
       antigens that compose the capsule. There is evidence not only for an
       association of lethal infections with serotype A in patients with
       advanced AIDS (34, 56), but also for a role for the capsule in directly
       influencing the infection of CD4+ cells by HIV (57). Together, these
       phenomena raise intriguing questions about the possible connection
       between the chemistry of these capsular antigens and cryptococcal
       infections in AIDS patients. One speculation is that AIDS creates the
       optimal physiological conditions for the establishment and spread of
       cryptococcosis. It has been observed that during the progression of AIDS
       there is a shift towards a T-2 response (14). This could lead to
       conditions that would inhibit the cellular immune responses that block
       dissemination of cryptococcal infections. Thus, an important
       consideration in the application of vaccine or immune modulation
       therapies in the treatment of cryptococcosis in AIDS victims would be
       the design of vaccines that could boost the T-1 immune response. It has
       been shown that the form and dose of an antigenic challenge can
       influence the induction of a T-1 or T-2 immune response (61). Recently,
       Murphy has reported that gamma interferon and interleukin 2 are
       up-regulated in the spleens of mice that produce anticryptococcal TDH
       and TAMP cells in response to immunogenic doses of cryptococcal culture
       filtrate antigen given with Freund's complete adjuvant (49). Perhaps
       purified cryptococcal antigens (e.g., MP) conjugated to an appropriate
       carrier or adjuvant could be used in therapeutic strategies to limit
       cryptococcosis in immunocompromised individuals. Future investigations
       of virulence and pathogenicity in the context of defined polysaccharide
       antigens from encapsulated strains of C. neoformans will contribute to a
       better understanding of the regulation of cryptococcal infection and
       immunity at the cellular and molecular levels.(ABSTRACT TRUNCATED AT 400
       WORDS)
 DE    Animal  Antigens, Fungal/*IMMUNOLOGY  Carbohydrate Sequence
       Cryptococcus neoformans/*IMMUNOLOGY  Human  Immunity  Molecular Sequence
       Data  Polysaccharides/*IMMUNOLOGY  Support, U.S. Gov't, P.H.S.  JOURNAL
       ARTICLE  REVIEW  REVIEW, TUTORIAL

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

