Researchers at Harvard Medical School have identified a gene in Asian monkeys that may have evolved as a defense against lentiviruses, the group of viruses that includes HIV. The study suggests that AIDS is not a new epidemic.
The gene, called TRIM5-CypA, well characterized elsewhere (AIDS, 2007; PNAS, 2008), is a hybrid of two existing cellular genes, TRIM5 and CypA. The combination produces a single protein capable of blocking infection by viruses closely related to HIV. Surprisingly, this is actually the second time researchers have identified a TRIM5-CypA gene in monkeys. The other hybrid gene, called TRIMCyp, was discovered in 2004 in South American owl monkeys.