Australian researchers have discovered that HIV-susceptible Langerhans cells on the inner surface of the foreskin and frenulum of uncircumcised men are poorly protected by a thin layer of keratin, a finding that may help explain why removal of this tissue during circumcision appears to reduce female-to-male transmission of HIV (McCoombe SG and Short RV. AIDS. 2006;20:1491-1495). Scientists suspect that the HIV receptor–bearing Langerhans cells in mucosal surfaces targeted by HIV serve as a primary point of viral entry following sexual exposure.
Stephenson J. HIV and Circumcision. JAMA. 2006;296(7):759. doi:10.1001/jama.296.7.759-b