Tonsillar application of AT-2 SIV affords partial protection against rectal challenge with SIVmac239.
BACKGROUND
Although mucosal responses are important for preventing infections with HIV, the optimal strategies for inducing them remain unclear. To evaluate vaccine strategies targeting the oral mucosal lymphoid tissue inductive sites as an approach to provide immunity at distal sites, we vaccinated healthy macaques via the palatine/lingual tonsils with aldrithiol 2 (AT-2) inactivated Simian immunodeficiency virus (SIV)mac239, combined with CpG-C immunostimulatory oligonucleotide (CpG-C ISS-ODN, C274) as the adjuvant.


METHODS
Macaques received 5 doses of C274 or control ODN C661 and AT-2 SIV on the tonsillar tissues every 6 weeks before being challenged rectally with SIVmac239, 8 weeks after the last immunization.


RESULTS
Although no T-cell or B-cell responses were detected in the blood before challenge, antibody (Ab) responses were detected in the rectum. Immunization with AT-2 SIV significantly reduced the frequency of infection compared with nonimmunized controls, irrespective of adjuvant. In the vaccinated animals that became infected, peak viremias were somewhat reduced. SIV-specific responses were detected in the blood once animals became infected with no detectable differences between the differently immunized groups and the controls.


CONCLUSIONS
This work provides evidence that vaccine immunogens applied to the oral mucosal associated lymphoid tissues can provide benefit against rectal challenge, a finding with important implications for mucosal vaccination strategies.
Center for Biomedical Research, HIV/AIDS Program, Population Council, New York, NY, USA.
Panagiotis
P
Vagenas
Vennansha G
VG
Williams
Michael
M
Piatak
Julian W
JW
Bess
Jeffrey D
JD
Lifson
James L
JL
Blanchard
Agegnehu
A
Gettie
Melissa
M
Robbiani
D015082:2,2'-Dipyridyl / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis / Q000097:blood; D004220:Disulfides / Q000494:pharmacology*; D018928:Immunity, Mucosal; D007413:Intestinal Mucosa; D008253:Macaca mulatta; D008297:Male; D009061:Mouth Mucosa; D016877:Oxidants / Q000494:pharmacology*; D014066:Palatine Tonsil / Q000276:immunology; D012007:Rectum / Q000276:immunology; D018449:SAIDS Vaccines / Q000008:administration & dosage* / Q000276:immunology; D016097:Simian Acquired Immunodeficiency Syndrome / Q000276:immunology / Q000517:prevention & control*; D015302:Simian Immunodeficiency Virus / Q000145:classification / Q000187:drug effects* / Q000276:immunology*; D015164:Vaccines, Inactivated / Q000008:administration & dosage / Q000276:immunology; D019562:Viral Load; D014766:Viremia / Q000276:immunology
D000914:Antibodies, Viral; D004220:Disulfides; D016877:Oxidants; D018449:SAIDS Vaccines; D015164:Vaccines, Inactivated; C001105:2,2'-dipyridyl disulfide; D015082:2,2'-Dipyridyl