FRIDAY, Dec. 17 (HealthDay News) -- Differences in immune signaling pathways among various species may explain why humans are more susceptible than other primates to certain infectious diseases, researchers say.

For example, when it comes to the progression of HIV to AIDS or severe complications from hepatitis B, it has been found that humans are more sensitive than chimpanzees to the serious effects of these viral infections, noted Luis B. Barreiro of the University of Chicago and colleagues.

In the new study, published in the Dec. 16 online edition of the journal PLoS Genetics, Barreiro's team conducted the first genome-wide comparison of genes regulated by the innate immune system in humans, chimpanzees and rhesus macaques. In order to identify functional differences in their immune pathways, the researchers stimulated immune cells from each of the three primate species.

The core response needed to fight any invading pathogen was similar in all three species. But there were differences in how the immune system fought off certain viral and microbial infections. This likely reflects rapid adaptation cycles between specific hosts and viruses, the study authors said.

One particularly interesting finding was that many HIV-interacting genes responded uniquely in chimpanzees, which may help explain why chimpanzees do not routinely develop AIDS after being infected with HIV, the study authors noted in a news release from the journal's publisher.

The researchers also found that human immune responses were particularly enriched for genes involved in cell death and cancer biology.

More information

The U.S. National Institute of Allergy and Infectious Diseases has more about the immune system.