Antibody Prevalence and Immune Profiles of Simian T‐Lymphotropic Virus Type 1 in Chinese Laboratory Macaques

ABSTRACT Background Simian T‐lymphotropic virus type 1 (STLV‐1) shares a high level of genetic homology with that of human (HTLV‐1) and naturally infects a large variety of old world non‐human primate species. However, the prevalence of STLV‐1 in Chinese laboratory macaques is still unknown. Methods A serological survey of STLV‐1 in 970 Chinese laboratory macaques from six regions was conducted, and the clinical immune responses in 24 cynomolgus macaques with natural STLV‐1 infection were profiled. Results The antibody prevalence for STLV‐1 in regions 1–6 was 4.5%, 6.5%, 5.0%, 8.5%, 14.5%, and 8.6%, respectively. A one‐way ANOVA revealed significant differences in the OD 405 nm values between the groups ( p = 0.0085). Furthermore, the prevalence in region 5 was significantly higher than that in regions 1, 2, and 3 ( χ 2 , p < 0.05). Both the OD 405 nm values and prevalence (%) in rhesus macaques were significantly higher than those in cynomolgus macaques. Elevated leukocyte counts and cytokine levels were observed in natural infections; however, the Th1/Th2 cytokine ratio showed no significant difference between STLV‐1 infected animals and healthy controls. Conclusions Survey results indicated that regional differences and animal husbandry levels might affect the infection rates of STLV‐1. The study also demonstrated that most STLV‐1‐infected macaques maintain a long‐term asymptomatic infection with a balanced Th1/Th2 response.