Cold stress equally enhances in vivo pro-inflammatory cytokine gene expression in chicken lines divergently selected for antibody responses

The effects of cold stress, immunization and genetic selection on the expression of mRNA for cytokine genes in poultry have not been completely elucidated. Therefore, in the present experiment, using real-time quantitative RT-PCR, we evaluated the effect of cold stress and immunization with complete Freund's adjuvant (CFA) on expression of mRNA for pro-inflammatory (interleukin-1 beta [IL-I beta], IL-6, IL-12 beta), Th-1 (IFN-gamma and IL-2), and Th-2 (IL-4 and IL-10) cytokine genes in peripheral blood leukocytes (PBL) of chicken lines divergently selected for either high or low antibody responses. Irrespective of the duration, cold stress enhanced expression of mRNA for IL-1 beta, IL-6, IL-12 beta and IL-4 cytokine genes in both selection lines. These results indicate that cold stress stimulates both the innate and parts of the adaptive cellular immune system. Immunization with CFA resulted in higher expression of mRNA for pro-inflammatory cytokines and lower expression of mRNA for both Th-1 and Th-2 cytokines. (c) 2005 Elsevier Ltd. All rights reserved