Cryptococcus neoformans differently regulates B7-1 (CD80) and B7-2 (CD86) expression on human monocytes

Anna Vecchiarelli, Claudia Monari, Cinzia Retini, Donatella Pietrella, Barbara Palazzetti, Lucia Pitzurra, Arturo Casadevall

Research output: Contribution to journalArticlepeer-review

Abstract

To induce a specific response in primary resting T cells, two signals must be provided by antigen-presenting cells (APC). The first antigen-specific signal is mediated by formation of the T cell receptor major histocompatibility complex molecule ternary complexes. The second signal is delivered by interaction of either B7-1 or B7-2 expressed by APC with CD28 or CTLA-4 on T cells. In this study, we examined the modulation of B7-1 and B7-2 molecules on human monocytes exposed to encapsulated or acapsular Cryptococcus neoformans or Candida albicans. In our experimental system, C. albicans or acapsular C. neoformans are able to induce B7-1 expression while the encapsulated yeast is a poor stimulator. A modest increase of B7-2 expression was also observed after monocyte treatment with acapsular C. neoformans or C. albicans, while the encapsulated yeast was ineffective in inducing B7-2 molecules. Kinetic analysis showed the maximum expression of B7-1 after 24 to 48 h. Addition of the opsonic IgG1 mAb 2H1 to monocytes and C. neoformans significantly increased B7-1, but not B7-2, expression. The contribution of B7-1 and B7-2 cc-stimulatory (CS) molecules to cryptococcal-specific T cell activation was analyzed and a substantial inhibition of T cell proliferation was observed. In this study we provide the first demonstration of fungal interference in the regulation of CS molecules. Our results suggest a potential mechanism for poor inflammatory responses observed in C. neoformans infections.

Original languageEnglish (US)
Pages (from-to)114-121
Number of pages8
JournalEuropean Journal of Immunology
Volume28
Issue number1
DOIs
StatePublished - Jan 1 1998
Externally publishedYes

Keywords

  • B7-1
  • Cc-stimulatory molecule
  • Cryptococcus neoformans
  • Monocyte

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology

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