Nonhuman Primate Researchers Gather in New Orleans

“Food in New Orleans is more of a religion,” Andrew Lackner, director of the Tulane National Primate Research Center (TNPRC), said in the opening remarks at this year’s 28th Annual Symposium on Nonhuman Primate Models for AIDS, which is taking place from October 19-22 in New Orleans. It was therefore quite appropriate that the almost 200 conference participants were given a New Orleans cookbook, which features “fifty-seven classic Creole recipes that will enable everyone to enjoy the special cuisine of New Orleans.” 

New Orleans is actually the place where the first Nonhuman Primate Models for AIDS meeting was held 28 years ago, said Ronald Veazey of Tulane University, one of the conference co-chairs this year. Three years ago, the meeting, which is held at one of the eight National Primate Research Centers in the US, should have taken place in New Orleans, Veazey says, but that got delayed because of Hurricane Katrina. By now, however, the city has rebounded quite strongly, TNPRC director Andrew Lackner said in his opening remarks. “There are actually more restaurants in the city than there were before Katrina,” he said.

This morning’s keynote speaker, Nobel laureate Françoise Barré-Sinoussi of the Institut Pasteur in Paris, reminded the audience that HIV research in nonhuman primates (NHPs) started more than 20 years ago in chimpanzees. “We started to work on animal models as early as 1984,” she said.

Many of the talks today were about current research efforts to characterize and improve or develop animal models of HIV transmission and infection in NHPs. For example, one important goal for researchers who work on NHP models for HIV and AIDS is to accurately model HIV transmission in humans. To do so, researchers need to use well characterized stocks of challenge viruses. One of them is simian immunodeficiency virus (SIV)smE660, a challenge stock that is similar to HIV in that it is a swarm, which means that it contains many different virus variants. But to accurately predict the immunogenicity of vaccines in challenge experiments, it is important to know how sensitive the challenge stocks used in such experiments are to neutralization by antibodies. 

Katharine Bar from the University of Alabama in Birmingham and her colleagues use single genome amplification (SGA) to characterize the neutralization sensitivity of variants in SIVsmE660 stocks as well as transmitted founder viruses of animals infected with SIVsmE660. They found that the majority of variants seem to be rather sensitive to neutralization, while some are quite resistant. This suggests that SIVsmE660 is actually a mix of variants with varying degrees of resistance to neutralization. 

Brandon Keele from the National Cancer Institute gave an update on attempts to develop an NHP model of HIV transmission to the penis. In the model, the penis of male rhesus macaques is exposed to different doses of SIVmac251. Using SGA, Keele and colleagues found that in most cases, this resulted in just one transmitted founder virus in the infected animal, similar to most cases of heterosexual transmission of HIV in humans. 

Other researchers are developing animal models of co-infections with HIV and other sexually transmitted infections (STIs). This is important because STIs are associated with an increased risk and rate of HIV infection. Tara Henning of the US Centers for Disease Control and Prevention (CDC) said she and her colleagues did the first successful triple infection of female pigtailed macaques with the SIV/HIV hybrid SHIVSF162P3, the single-celled protozoan parasite Trichomonas vaginalis and the bacterium Chlamydia trachomatis, with clinical presentation of genital STI symptoms that were similar to those observed in humans.