Risk of immunodeficiency virus infection may increase with vaccine-induced immune response.
J Virol
; 86(19): 10533-9, 2012 Oct.
Article
in En
| MEDLINE
| ID: mdl-22811518
ABSTRACT
To explore the efficacy of novel complementary prime-boost immunization regimens in a nonhuman primate model for HIV infection, rhesus monkeys primed by different DNA vaccines were boosted with virus-like particles (VLP) and then challenged by repeated low-dose rectal exposure to simian immunodeficiency virus (SIV). Characteristic of the cellular immune response after the VLP booster immunization were high numbers of SIV-specific, gamma interferon-secreting cells after stimulation with inactivated SIV particles, but not SIV peptides, and the absence of detectable levels of CD8(+) T cell responses. Antibodies specific to SIV Gag and SIV Env could be induced in all animals, but, consistent with a poor neutralizing activity at the time of challenge, vaccinated monkeys were not protected from acquisition of infection and did not control viremia. Surprisingly, vaccinees with high numbers of SIV-specific, gamma interferon-secreting cells were infected fastest during the repeated low-dose exposures and the numbers of these immune cells in vaccinated macaques correlated with susceptibility to infection. Thus, in the absence of protective antibodies or cytotoxic T cell responses, vaccine-induced immune responses may increase the susceptibility to acquisition of immunodeficiency virus infection. The results are consistent with the hypothesis that virus-specific T helper cells mediate this detrimental effect and contribute to the inefficacy of past HIV vaccination attempts (e.g., STEP study).
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Simian Acquired Immunodeficiency Syndrome
/
Simian Immunodeficiency Virus
Type of study:
Etiology_studies
/
Prognostic_studies
/
Risk_factors_studies
Limits:
Animals
/
Female
/
Humans
/
Male
Language:
En
Journal:
J Virol
Year:
2012
Type:
Article
Affiliation country:
Germany