Natural and cross-inducible anti-SIV antibodies in Mauritian cynomolgus macaques

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Date
2017-10-05Author
Li, Hongzhao
Nykoluk, Mikaela
Li, Lin
Liu, Lewis
Omange, Robert
Soule, Geoff
Schroeder, Lukas
Toledo, Niki
Kashem, Mohammad
Correia-Pinto, Jorge
Liang, Binhua
Schultz-Darken, Nancy
Alonso, Maria
Whitney, James
Plummer, Francis
Luo, Ma
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Show full item recordAbstract
Cynomolgus macaques are an increasingly important nonhuman primate model for HIV vaccine research. SIV-free animals without pre-existing anti-SIV immune responses are generally needed to evaluate the effect of vaccine-induced immune responses against the
vaccine epitopes. Here, in order to select such animals for vaccine studies, we screened
108 naïve female Mauritian cynomolgus macaques for natural (baseline) antibodies to SIV
antigens using a Bio-Plex multiplex system. The antigens included twelve 20mer peptides
overlapping the twelve SIV protease cleavage sites (-10/+10), respectively (PCS peptides), and three non-PCS Gag or Env peptides. Natural antibodies to SIV antigens were detected in subsets of monkeys. The antibody reactivity to SIV was further confirmed by Western blot using purified recombinant SIV Gag and Env proteins. As expected, the immunization of monkeys with PCS antigens elicited anti-PCS antibodies. However, unexpectedly, antibodies to non-PCS peptides were also induced, as shown by both Bio-Plex and Western blot analyses, while the non-PCS peptides do not share sequence homology with PCS peptides. The presence of natural and vaccine cross-inducible SIV antibodies in Mauritian cynomolgus macaques should be considered in animal selection, experimental design, and result interpretation, for their best use in HIV vaccine research.