Initiation of humoral immunity. I. The role of cytokines and hormones in the initiation of humoral immunity using T-independent and T-dependent antigens

The early events during the initiation of immune responses following the injection of T-independent (lipopolysaccharide, LPS) and T-dependent (bovine serum albumin, BSA) antigens were studied in immature male chickens. Specifically, the role of cytokines and hormones in the initiation of humoral immunity against these antigens was investigated. Both interleukin-1 (IL-1) and tumor necrosis factor (TNF-α) increased significantly post-LPS but not post-BSA injection. While interleukin-2 (IL-2) significantly decreased post-LPS injection, IL-2 significantly increased post-BSA injection. Furthermore, corticosterone levels significantly increased and tri-iodothyronine (T 3) levels significantly decreased post-LPS but not post-BSA injection. In this study, the results indicate that although LPS and BSA can induce a humoral antibody response in chickens, they activate different cytokines and neuroendocrine network systems.