Mauritian cynomolgus macaques with M3M4 MHC genotype control SIVmac251 infection

Background Understanding natural HIV control may lead to new preventative or therapeutic strategies. Several protective major histocompatibility complex (MHC) genotypes were found in humans and rhesus macaques. Here, we report a simian immunodeficiency virus (SIV) controller MHC genotype in Mauritian cynomolgus macaques (MCMs). Methods Twelve MHC‐genotyped MCMs were infected with SIVmac251 and monitored for viral loads and CD4+ T‐cell counts. Results Two macaques with M3M4 genotype exhibited the lowest peak viral loads (log plasma SIV RNA copies/mL), nearly 3 logs lower than those in most macaques with other MHC haplotype combinations, and set point viral loads below the level of detection limit by RT‐qPCR (500 cells/μL blood, while CD4 counts in the vast majority of other macaques were below this level. Conclusions The M3M4 MHC genotype may confer enhanced control of SIV replication in MCMs.