Protection of rhesus macaques from SIV infection by immunization with different experimental SIV vaccines.
The immunogenicity and efficacy of an inactivated whole SIVmac (32H) preparation adjuvanted with muramyl dipeptide (SIV-MDP) and a gp120-enriched SIVmac (32H) ISCOM preparation (SIV-ISCOM), were compared by immunizing four rhesus macaques (Macaca mulatta) four times with SIV-MDP and four others in the same way with SIV-ISCOM. Two monkeys immunized with whole inactivated measles virus (MV) adjuvanted with MDP (MV-MDP) and two monkeys immunized with MV-ISCOM served as controls. In the SIV-ISCOM-immunized monkeys higher SIV-specific serum antibody titres were found than in the SIV-MDP-immunized monkeys. In contrast to the MV-immunized monkeys all SIV-MDP- and SIV-ISCOM-immunized monkeys were protected against intravenous challenge 2 weeks after the last immunization with 10 median monkey infectious doses (MID50) of a cell-free SIVmac (32H) challenge stock propagated in the human T-cell line C8166. After 43 weeks the protected monkeys were reboosted and 2 weeks later rechallenged with 10 MID50 of the same virus produced in peripheral blood mononuclear cells (PBMC) from a rhesus macaque. None of these animals proved to be protected against this challenge. In a parallel experiment in which the same numbers of monkeys were immunized in the same way, the animals were challenged intravenously with 10 MID50 of PBMC from an SIVmac (32H)-infected rhesus macaque. Two out of four SIV-MDP- and two out of four SIV-ISCOM-immunized monkeys proved to be protected from SIV infection.
de Vries
P
P
Laboratory of Immunobiology, National Institute of Public Health and Environmental Protection, Bilthoven, The Netherlands.
Heeney
J L
JL
Boes
J
J
Dings
M E
ME
Hulskotte
E G
EG
Dubbes
R
R
Koornstra
W
W
ten Haaft
P
P
Akerblom
L
L
Eriksson
S
S
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D002460:Cell Line; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000821:virology; D008253:Macaca mulatta; D018449:SAIDS Vaccines / Q000008:administration & dosage / Q000276:immunology*; D016097:Simian Acquired Immunodeficiency Syndrome / Q000503:physiopathology / Q000517:prevention & control*; D015302:Simian Immunodeficiency Virus / Q000276:immunology; D014611:Vaccination; D014766:Viremia
D000914:Antibodies, Viral; D018449:SAIDS Vaccines