Immunologic aspects of oral candidiasis

Area of Science:

• Immunology
• Microbiology
• Oral Biology

Background:

• Immunity to Candida infections is complex due to varied candidiasis types, Candida forms, and mucosal/systemic immune interactions.
• Mucosal candidiasis is common, but systemic infections also occur with potentially different immune mechanisms.
• Oral candidiasis presents with four main types, involving yeast and hyphal forms of Candida with distinct antigens.

Purpose of the Study:

• To explore the complexities of human immunity against Candida infections.
• To differentiate the roles of mucosal versus systemic immunity in combating Candida.
• To investigate the specific contributions of humoral and cell-mediated immunity in various forms of candidiasis.

Main Methods:

• Review of existing literature on Candida immunity.
• Analysis of humoral immunity (salivary and serum antibodies).
• Evaluation of cell-mediated immunity (macrophages, polymorphonuclear leukocytes) and antifungal salivary proteins.

Main Results:

• Salivary antibodies inhibit Candida adherence and show protection in animal models.
• Serum antibodies against a 47kD antigen correlate with recovery from systemic candidiasis.
• Macrophages and polymorphonuclear leukocytes kill Candida yeast and inhibit hyphal forms; these cells may be crucial in vivo.

Conclusions:

• Cellular factors likely provide primary defense against mucocutaneous Candida infections.
• Humoral factors, particularly serum antibodies, play a more significant role in preventing systemic Candida dissemination.
• Saliva contains antifungal proteins that may work with specific immune factors for enhanced protection.