Effects of Chronic Viral Infection on Lymphocyte Populations in Middle-aged Baboons ( Papio anubis)

Comp Med. 2021 Apr 1;71(2):177-187. doi: 10.30802/AALAS-CM-20-000068. Epub 2021 Feb 12.


Aging of the immune system is characterized by the loss of naïve T-cells, increased inflammation, and immune function impairment. Chronic infection with cytomegalovirus is thought to play a role in age-related changes in immunity. Therefore, to assess the effect of pathogens such as cytomegalovirus on the immune system, we determined lymphocyte populations and inflammatory markers over a 3-y period in captive, middle-age baboons, with various exposure to pathogens and shedding pressure. Groups included SPF (i.e., pathogen-negative; n = 14); large-group, conventionally housed (CONV LG; pathogen- positive; n = 14), and small-group, conventionally housed (CONV SM; pathogen-positive; n = 7). All baboon groups showed a decrease in CD45RA+ CD28+ (i.e., naive) cells over time during middle age, but the rate of decline appeared faster in CONV LG baboons than in the other groups. In addition, the reduction in CD45RA+ CD28+ cells in the CONV LG baboons coincided with higher IgG levels against baboon cytomegalovirus, increased serum cortisol concentration, and a greater inflammatory phenotype. The results of this project support a role for cytomegalovirus infection in immune system alterations in middle-aged baboons.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aging
  • Animals
  • Cytomegalovirus Infections*
  • Papio
  • Papio anubis*
  • T-Lymphocytes