This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. This was a pilot proposal to determine the feasibility of, and optimize the procedures involved in circumcising and collecting penile biopsies from rhesus macaques for SIV/AIDS vaccine studies. A major HIV vaccine trial ended in November 2008, which concluded that there was an increased risk for men acquiring HIV after being vaccinated, if and only if the males were not circumcised. Thus, there is currently a lot of speculation and concern among scientists as to why a vaccine that is supposed to protect persons from HIV would actually increase the persons'risk if they were not circumcised. However, a suitable animal model has not been developed so we wish to perform pilot studies to see if a model for HIV transmission to the penis can be established. This 1 year project was funded by an administrative supplement to the base grant demonstrated this was feasible, and that the macaque foreskin and penis was sufficiently similar to those of men to use as a model for circumcision and HIV transmission. This project was initiated and completed in the last year and a new project (Minh Dinh, PI) has been funded to continue such studies in determining the mechanisms of HIV and SIV entry into the male reproductive system.