A single vaccination with attenuated SIVmac 239 via the tonsillar route confers partial protection against challenge with SIVmac 251 at a distant mucosal site, the rectum.
Elucidating the mechanisms that protect monkeys previously immunized with attenuated SIV (SIVDeltanef) against challenge infection with pathogenic virus may reveal new strategies for the development of an effective HIV vaccine. Here we show that a single atraumatic application of SIVDeltanef to the tonsils of four rhesus macaques conferred protection against SIVmac251 applied intrarectally 26 weeks later. While this protection was not complete, i.e., challenge virus could be isolated from all immunized animals, it was reflected by significantly lower viral loads in the blood (weeks 2-16 after challenge, p < 0.01) and considerably lower loads in lymphoid organs, and more stable peripheral CD4 counts in a proportion of the immunized animals as compared to four non-immunized, SIVmac251-infected control monkeys. SIV-specific humoral as well as systemic and mucosal T cell responses were detected in the immunized animals, but there was no correlation between their magnitude of expression and the level of protection. Analyses of leukocyte subsets in these animals at necropsy (24 weeks after challenge) did not reveal a significantly enhanced proportion of gamma/delta T cells in the tissues of protected monkeys. Therefore, tonsillar application of attenuated SIV induces protection in some animals against a superinfection with wild-type SIV distant at a distant mucosal site.
Stahl-Hennig
Christiane
C
German Primate Center, D-37077 Göttingen, Germany.
Eisenblatter
Martin
M
Franz
Monika
M
Stoiber
Heribert
H
Tenner-Racz
Klara
K
Suh
You-Suk
YS
Jasny
Edith
E
Falkensammer
Barbara
B
Ugucchioni
Mariagrazia
M
Georgsson
Gudmundur
G
Baroni
Carlo
C
Dierich
Manfred P
MP
Lifson
Jeffrey D
JD
Steinman
Ralph M
RM
Uberla
Klaus
K
Racz
Paul
P
Ignatius
Ralf
R
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D005260:Female; D017353:Gene Deletion; D015754:Genes, nef; D007111:Immunity, Cellular; D007413:Intestinal Mucosa / Q000276:immunology / Q000821:virology; D008198:Lymph Nodes / Q000821:virology; D008253:Macaca mulatta; D008297:Male; D014066:Palatine Tonsil / Q000821:virology; D012367:RNA, Viral / Q000032:analysis; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000032:analysis; D012007:Rectum / Q000821:virology; D018449:SAIDS Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D016097:Simian Acquired Immunodeficiency Syndrome / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D015302:Simian Immunodeficiency Virus / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology
D000914:Antibodies, Viral; D012367:RNA, Viral; D016692:Receptors, Antigen, T-Cell, gamma-delta; D018449:SAIDS Vaccines; D014613:Vaccines, Attenuated