Special Proteins Provide Possible Explanation Why Oral Transmission of HIV Is Uncommon
December 30, 2003
In the following article and an article by G. Sonia Nagy, M.D., we will entertain two different views on oral sex transmission of the HIV virus.
Editor's note: Uncommon does not mean zero. Oral transmission of HIV is a documented phenomenon.
Oral transmission rates of HIV are low, as indicated by data indicating that over 90% of HIV infections occur across other mucosal surfaces. But the reason for this was obscure until results of a study looked at some special proteins present in the cells that line the mouth became available. The proteins are called human biodefensins. Normally, these are expressed by certain cells only during the inflammatory process, but the cells of the mouth lining make these proteins under normal conditions. Human biodefensins -2 and -3 (but not -1) appear to inhibit the formation of the CXCR4 receptor on the cell surface, thus removing a port of cell entry for HIV. Interestingly, these biodefensins do not inhibit the formation of the CCR5 receptors, which are another port of entry for HIV. This may explain why most oral HIV transmissions are of a form of the virus that prefers the CCR5 portal rather than CXCR4.
If you wish to read the entire journal article, please note the following citation: Quinones-Mateu, M., et. al. Human epithelial b-defensins 2 and 3 inhibit HIV-1 replication, AIDS 2003, vol. 17, no. 16. F-39-F48.
This article was provided by Seattle Treatment Education Project. It is a part of the publication STEP Ezine.