J Leukoc Biol. 2026 Jun 5:qiag069. doi: 10.1093/jleuko/qiag069. Online ahead of print.
ABSTRACT
People living with HIV experience an earlier risk for onset of aging-related chronic inflammatory comorbidities including cardiovascular disease. We previously showed that the proportion of macrophages was higher in the heart of older rhesus macaques (Macaca mulatta) with normal histopathology as well as in all age groups of macaques with cardiac pathology. This present study investigates the effects of simian immunodeficiency virus (SIV) infection on cell density and macrophages in heart tissues of adult rhesus macaques. Heart tissues were evaluated by H&E and immunofluorescence staining to assess the number and phenotype of heart macrophages that could change with SIV infection. Cardiac cellularity was lower in hearts of SIV-infected young and adult macaques, as well as in uninfected aged macaques, compared with uninfected adult rhesus macaques. This lower cellularity was associated with higher percentages of CD163+ macrophages in hearts of SIV-infected young adult macaques similar to uninfected aged macaques. Higher percentages of CD163+ macrophages were also observed in diseased hearts of both SIV-infected and uninfected adult animals that appeared to be short-lived macrophages based BrdU-labeling. In contrast, macrophages retaining in vivo-administered dextran, indicative of long-lived macrophages, predominated among cardiac macrophages in both SIV-infected and uninfected animals of all ages. Together, these results suggest that SIV infection induces changes in cardiac cellularity and macrophage composition that resemble those observed during aging. This rhesus macaque model supports continued studies to further dissect the shifting dynamics of macrophage subsets and their role in heart adaptations in response to HIV infection and aging.
PMID:42244406 | DOI:10.1093/jleuko/qiag069