Oral HIV-exposure elicits mucosal HIV-neutralizing antibodies in uninfected men who have sex with men.
OBJECTIVE
To determine whether oral sexual exposure to HIV-1 (HIV) results in HIV-neutralizing activity in saliva of uninfected men who have sex with infected men?


METHODS
Saliva samples were collected from HIV IgG seronegative men (n = 25) whose male partners were HIV infected and from low-risk healthy controls (n = 22) and analyzed for HIV-neutralizing capacity.


METHODS
The presence of neutralizing activity in saliva was tested in a peripheral blood mononuclear cell-based assay using primary HIV isolates. Self-reporting questionnaires described the individuals' sexual behaviors and routes of possible HIV exposure.


RESULTS
Of 25 exposed, uninfected individuals (EUI), 21 reported receptive unprotected oral intercourse, whereas three of the 25 reported unprotected anal receptive intercourse. Whole saliva from both EUI and low-risk healthy controls contained HIV-neutralizing activity. However, a significant difference was seen when analyzing the salivary IgA1 fraction: 13 of 25 EUI neutralized HIV, whereas none of the 22 controls had this capacity. The neutralizing capacity of the EUI males persisted during 2 years of follow-up.


CONCLUSIONS
Unprotected oral sex evokes a salivary IgA1-mediated HIV-neutralizing response that persists over time during continuous exposure in uninfected male partners of infected men.
Hasselrot
Klara
K
Department of Medicine, Center for Molecular Medicine, Karolinska Institutet, Karolinska University Hospital, Solna, Stockholm, Sweden. klara.hasselrot@ki.se
Säberg
Pär
P
Hirbod
Taha
T
Söderlund
Johan
J
Ehnlund
Mariethe
M
Bratt
Göran
G
Sandström
Eric
E
Broliden
Kristina
K
D000328:Adult; D015331:Cohort Studies; D015483:HIV Antibodies / Q000096:biosynthesis*; D015658:HIV Infections / Q000276:immunology* / Q000635:transmission / Q000821:virology; D015497:HIV-1 / Q000276:immunology*; D018451:Homosexuality, Male; D006801:Humans; D018928:Immunity, Mucosal; D007070:Immunoglobulin A / Q000096:biosynthesis; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000276:immunology; D012463:Saliva / Q000276:immunology; D012725:Sexual Behavior; D047568:Unsafe Sex
D015483:HIV Antibodies; D007070:Immunoglobulin A