New! Sign up for our free email newsletter.
Science News
from research organizations

Sperm May Play Leading Role In Spreading HIV

Date:
October 26, 2009
Source:
Rockefeller University Press
Summary:
Sperm, and not just the fluid it bathes in, can transmit HIV to macrophages, T cells, and dendritic cells (DCs), researchers report. By infecting DCs, which carry the virus and potently pass it to T cells, sperm may play a leading role in spreading HIV.
Share:
FULL STORY

Sperm, and not just the fluid it bathes in, can transmit HIV to macrophages, T cells, and dendritic cells (DCs), report a team led by Ana Ceballos at the University of Buenos Aires in Argentina. By infecting DCs, which carry the virus and potently pass it to T cells, sperm may play a leading role in spreading HIV.

The article appears in the November 23, 2009 issue of the Journal of Experimental Medicine (online October 26).

During sexual intercourse, HIV-infected men transmit HIV through their semen, which carries free-floating virus as well as HIV-infected leukocytes. Traces of HIV have been detected on sperm as well, but the role they play in viral transmission has been a matter of debate. After all, men with vasectomies can transmit HIV. Now, Ceballos et al. show that HIV attaches to the surface of sperm and that these HIV carriers pass on the virus to DCs and other HIV targets.

Sperm express molecules known to interact with HIV's envelope, such as heparan sulfate and mannose receptors. The authors show that HIV relies on heparan sulfate to attach to sperm, but not mannose receptors as previously predicted.

Once attached, the virus was transmitted from sperm to DCs in culture. The DC receptors CD4 and DC-SIGN were required for transmission, suggesting that DCs pick up the virus by binding to sperm rather than by ingesting them. DCs matured after interacting with the sperm, producing tolerance-promoting cytokines like interleukin-10. The authors speculate that this immune-suppressing profile, versus an inflammatory profile, might also help the virus spread.

Sperm might reach DCs by passing through microabrasions in the vaginal or anal lining that often form during intercourse, suggest the authors. Or they might contact the finger-like projections of DCs that extend to the surface of mucosal linings. Furthermore, the team found that a slightly acidic pH, similar to the pH in the vagina after sex, promoted HIV-sperm binding and the subsequent rate of sperm-related DC infection.


Story Source:

Materials provided by Rockefeller University Press. Note: Content may be edited for style and length.


Cite This Page:

Rockefeller University Press. "Sperm May Play Leading Role In Spreading HIV." ScienceDaily. ScienceDaily, 26 October 2009. <www.sciencedaily.com/releases/2009/10/091026093715.htm>.
Rockefeller University Press. (2009, October 26). Sperm May Play Leading Role In Spreading HIV. ScienceDaily. Retrieved March 28, 2024 from www.sciencedaily.com/releases/2009/10/091026093715.htm
Rockefeller University Press. "Sperm May Play Leading Role In Spreading HIV." ScienceDaily. www.sciencedaily.com/releases/2009/10/091026093715.htm (accessed March 28, 2024).

Explore More

from ScienceDaily

RELATED STORIES