<prompt> Salivary protein, which prevents transmission of human immunodeficiency virus via saliva is:SialoperoxidaseSecretory IgASalivary leukocyte proteinase inhibitorHistidine rich proteins  <response>: Secretory leukocyte protease inhibitor SLPI is found in human saliva, nasal secretions, tears, cervical mucus and seminal fluid. It is believed to be responsible for the anti-HIV properties of external secretions. 