Study Shows Component of Saliva is Very Effective in Blocking
AIDS Virus Potential for Use in Preventing Sexual Transmission
of HIV (No mention of Procept, just for information only)
NEW YORK, Jan. 7 /PRNewswire/ -- Research conducted at The New York Hospital-Cornell University
Medical College has found that a natural component of human saliva has a very powerful effect in
blocking the growth of laboratory strains of HIV as well as AIDS viruses taken directly from patients.
This finding could lead to the development of natural inhibitors to HIV transmission.
In a study published in the January 5 issue of the Journal of Experimental Medicine, Dr. Jeffrey
Laurence, Director of the Laboratory for AIDS Virus Research; Dr. Ralph Nachman, Chairman of the
Department of Medicine; Dr. Roy L. Silverstein, Chief of the Division of Hematology-Oncology; and a
team of biomedical scientists describe how they have identified a natural sugar-protein, concentrated in
saliva, known as TSP (thrombospondin), and discovered its remarkable ability to block the growth of the
AIDS virus.
Recognizing that over the past years several labs have found a variety of substances in human saliva
that partially inhibit the growth of HIV, Dr. Laurence and his research team delved further into this
phenomenon.
Dr. Laurence said, ''We began by exploring why there is so little HIV virus in saliva, while large amounts
of the virus are found in other body fluids; and why human saliva is so effective at blocking the growth of
the AIDS virus in the test tube. This led us to the discovery of TSP.''
According to Dr. Laurence, ''We made the observation that thrombospondin type 1 (TSP-1) can block
HIV-1 infection of primary human cells and transform human cell lines of T lymphocyte and monocyte
lineages. TSP is effective against both laboratory-adapted strains of HIV-1 and HIV-1 patient isolates. It
is active at physiologic concentrations. Saliva experiments indicate that TSP-1 is a major component of
the natural HIV inhibitory capacity of saliva.''
TSP is of particular interest as a natural inhibitor, as others have shown that it may promote wound
healing, and suppression of some bacterial infections. Higher levels of TSP in the saliva of some male,
as opposed to female, animals may relate to the more frequent wounding of male animals. Wound
licking, with application of saliva molecules that could inhibit infection, would then be very beneficial.
Speaking of the application of this research, Dr. Nachman said, ''This is an exciting finding that is
another step forward in our research efforts aimed at preventing AIDS transmission. TSP derivatives
could potentially be used vaginally, rectally and orally in condoms, foams, suppositories, mouthwashes
and toothpastes to inhibit transmission of the AIDS virus.''
While TSP is a very large molecule that would be unwieldy to use directly in patients, the Cornell
research team also investigated the mechanism of action of TSP. They found that peptides -- small
pieces of the larger TSP -- could block binding of the AIDS virus to its receptor on immune cells. This
offers the potential for direct use of these smaller molecules to prevent sexual transmission of HIV.
Funding for this work was provided by the Dental, Heart/Lung/Blood, and Allergy/Immunology Institutes
of the NIH.
SOURCE: The New York Hospital - Cornell Medical Center |
