Nittayananta1, W., Coombs1, R.W., Ayehunie2, S., Klausner2, M., Dale1, B.A. 1University of Washington, Seattle, WA; 2MatTek Corporation, Ashland, MA, United States.

This study by scientists at the University of Washington and MatTek Corp. demonstrated that MatTek’s EpiOral in vitro human buccal (inner cheek) tissue equivalent can be used for studying the effect of beta-defensins (hBD) on oral HIV transmission. Background: As part of innate immunity, oral mucosal epithelial cells secrete a class of antimicrobial peptides termed human beta-defensins (hBD). HIV induces expression of hBD-2 and hBD-3 mRNA in human oral epithelial cells; however, the role of hBD in HIV transmission using a human oral tissue model has not been studied. Methods: We used a human buccal epithelial cell tissue raft system (MatTek Corp., Ashland, MA) to evaluate the effect of in vitro mixed-lymphocyte culture conditions for HIV replication on the expression of hBD-2 and hBD-3. The tissues were cultured for 48 hours under the following conditions; IL-2 alone, IL-2 plus peripheral blood mononuclear cells (PBMC; 1×10^6 versus 10×10^6), either alone or in combination, and presented to either the top or the bottom of the tissue raft. The tissue with culture media alone was used as a control. Expression of hBD-2 and hBD-3 was determined at both transcription (mRNA) and translation levels by reverse transcriptase (RT)-PCR amplification and immunohistochemistry (IHC), respectively. Results: The expression of hBD-2 and hBD-3 was increased when medium containing IL-2 alone or IL-2 plus PBMC was present on the top compared to the bottom of the tissue raft. The up-regulation of hBD was higher in the presence of both IL-2 and PBMC compared to IL-2 alone. However, increasing the concentration of PBMC from 1×10^6 to 10×10^6 decreased the expression of hBD. Conclusions: Our preliminary data suggest that this in vitro human epithelial tissue model is biologically plausible as we showed a mucosal polarity to hBD expression under controlled conditions; as such, this model may be useful for studying the effect of beta-defensins on oral HIV transmission. To this end, we have initiated experiments to determine the effects of both cell free- and cell-associated HIV-1 on hBD expression.


Anti-microbial, Anti-microbial peptides, Antimicrobial, Antimicrobial peptides, Beta-defensins, Buccal, EpiOral, Epithelial cells, HBD-2, HBD-3, HBD-3 mRNA, HIV, Human beta-defensin 2 (hBD-2), Human beta-defensin 2 mRNA, Human beta-defensin 3 (hBD-3), Human buccal epithelial, Messenger RNA expression, Mucosal polarity, Mucosal surfaces, Oral HIV transmission, Oral epithelial tissue model, Oral tissue, R5 virus, Submucosal, hBD-2, hBD-3, hBD-3 mRNA

Materials Tested

HIV-1, R5 virus

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