Identification of the major histocompatibility complex class-II DM and DO alleles in a cohort of northern pig-tailed macaques (Macaca leonina)

HIV-1 but not SIVmac239 induces higher interferon-α antiviral state in chronic infected northern pig-tailed macaques (Macaca leonina)

Studies have shown that interferon (IFN)-α has an inhibitory effect on human immunodeficiency virus type 1 (HIV-1) replication in the acute infection stage, but its role in chronic infection is still unclear. We previously established a nonpathogenic HIV-1 and pathogenic simian immunodeficiency virus (SIV) model in northern pig-tailed macaques (NPMs, Macaca leonina). In the current study, we detected viral RNA and DNA in various tissues (axillary lymph nodes (LNs), inguinal LNs, and spleen) in HIV-1_NL4-3- and SIV_mac239-infected NPM during the chronic stage of infection. Results indicated that the levels of viral DNA and RNA were higher in the tested tissues (LNs and spleen) of the SIV_mac239-infected NPMs than in the HIV-1_NL4-3 infected NPMs. Furthermore, IFN-α expression was higher in the HIV-infected tissues than in the SIV-infected controls. The HIV restriction factors induced by IFN-α (i.e., tetherin and MX2), as well as inflammatory factors IFN-γ, tumor necrosis factor-α (TNF-α), and interleukin 6 (IL-6), were analyzed using real-time polymerase chain reaction (PCR) and immunofluorescence staining assays. Results showed that their expression levels were much higher in the HIV-infected tissues than in the SIV-infected controls. These findings were confirmed by in vitro experiments on healthy NPM peripheral blood mononuclear cells infected with HIV-1_NL4-3, which showed lower viral replication, higher IFN-α expression, and an antiviral status. This study demonstrated that HIV-1 infection, but not SIV_mac239 infection, in NPMs caused higher expression of IFN-α and induced a higher antiviral status. This may be one of the reasons why HIV-1 cannot replicate at a high level or develop into AIDS in NPMs.

Superior intestinal integrity and limited microbial translocation are associated with lower immune activation in SIVmac239-infected northern pig-tailed macaques (Macaca leonina)

Microbial translocation is a cause of systemic immune activation in HIV/SIV infection. In the present study, we found a lower CD8+ T cell activation level in Macaca leonina (northern pig-tailed macaques, NPMs) than in Macaca mulatta (Chinese rhesus macaques, ChRMs) during SIVmac239 infection. Furthermore, the levels of plasma LPS-binding protein and soluble CD14 in NPMs were lower than those in ChRMs. Compared with ChRMs, SIV-infected NPMs had lower Chiu scores, representing relatively normal intestinal mucosa. In addition, no obvious damage to the ileum or colon epithelial barrier was observed in either infected or uninfected NPMs, which differed to that found in ChRMs. Furthermore, no significant microbial translocation (Escherichia coli) was detected in the colon or ileum of infected or uninfected NPMs, which again differed to that observed in ChRMs. In conclusion, NPMs retained superior intestinal integrity and limited microbial translocation during SIV infection, which may contribute to their lower immune activation compared with ChRMs.

Nomenclature report 2019: major histocompatibility complex genes and alleles of Great and Small Ape and Old and New World monkey species

The major histocompatibility complex (MHC) is central to the innate and adaptive immune responses of jawed vertebrates. Characteristic of the MHC are high gene density, gene copy number variation, and allelic polymorphism. Because apes and monkeys are the closest living relatives of humans, the MHCs of these non-human primates (NHP) are studied in depth in the context of evolution, biomedicine, and conservation biology. The Immuno Polymorphism Database (IPD)-MHC NHP Database (IPD-MHC NHP), which curates MHC data of great and small apes, as well as Old and New World monkeys, has been upgraded. The curators of the database are responsible for providing official designations for newly discovered alleles. This nomenclature report updates the 2012 report, and summarizes important nomenclature issues and relevant novel features of the IPD-MHC NHP Database.