Salivary protein which prevents transmission of HIV via saliva is:

 # Salivary protein which prevents transmission of HIV via saliva is:

A. Sialoperoxidase

B. Secretory IgA

C. Salivary leukocyte protease inhibitor

D. Histidine rich proteins

The correct answer is C. Salivary leukocyte protease inhibitor.

SLPI blocks HIV-1 infection of macrophages and primary T cells at concentrations (1–10 μg/mL) that occur naturally in saliva (Shugars and Wahl, 1998). These findings suggest that SLPI may be partially responsible for the low rate of oral transmission of HIV-1.