Anatomic site and immune function correlate with relative cytokine mRNA expression levels in lymphoid tissues of normal rhesus macaques

Abstract

Reverse transcriptase real-time polymerase chain reaction was used to determine pro-inflammatory, anti-viral and immunoregulatory cytokine mRNA expression levels in peripheral blood mononuclear cells (PBMC) of healthy juvenile, adolescent and adult rhesus macaques. Few age-related changes in cytokine mRNA expression levels were observed. Expression of interleukin 2 and Mx, a type I interferon-inducible gene, decreased with age, whereas interleukin 4 and macrophage inflammatory protein 1 (MIP-1) alpha and beta mRNA levels increased in older monkeys. Independent of age, the pro-inflammatory cytokines [tumour necrosis factor alpha (TNF-alpha) and chemokines] were expressed at higher mRNA levels in PBMC than the immunoregulatory cytokines (interleukins 2, 4, 12). Pro-inflammatory cytokine mRNA expression levels were highest in lymphoid tissues draining mucosal surfaces. Thus, a correlation exists between cytokine mRNA levels in lymphoid tissues and the anatomical site.