Effect of Oral Microbiome on HIV-Host Interactions

Objectives: Although HIV RNA can be detected in saliva, oral cavity is an inefficient route for the HIV transmission. The participation of oral microbiome in the resistance of oral mucosa remains largely unknown. This in vitro study determined the effect of several oral microorganism metabolites on HIV pathogenesis.
Methods: The initial investigation consisted of evaluating the effect of several oral microorganism metabolites (and ) against HIV. The microorganisms at 2x10³CFU/mL were cultured in BHI media at 37 °C, 5% CO₂. After 24h the cultures were centrifuged and the supernatants were filtered (0.02μm). TZM-bl cells at 5x10⁴cells/mL were exposed to the microbial supernatant and HIV Bal and cultured in DMEM 10% FBS at 37 °C, 5% CO₂ . After 72 h the cytotoxicity and anti-HIV activity were determined.
Results: Actinobacillus actinomycetemcomitans, Actinomyces naeslundii, Streptococcus gordonii and Candida albicans did not affect the cell viability. Streptococcus mutans, Streptococcus oralis and Streptococcus sanguinis supernatants significantly decreased (p<0.01) the cell viability. Based on cytotoxicity data, only Actinobacillus actinomycetemcomitans, Actinomyces naeslundii, Streptococcus gordonii and Candida albicans were evaluated for anti-HIV effect. Candida albicans supernatant significantly decreased (p<0.01) the percentage of HIV infection in comparison controls group.
Conclusions: This study determined the anti-HIV activity of C. albicans metabolites against HIV-1. At this stage, it is not known if the effects were on specific viral glycoproteins of the attachment pathway (gp120/gp41) or a result of anti-enzymatic (reverse transcriptase, integrase or protease) activity.