Cytokine mRNA expression in leukocytes of efferent lymph from stimulated lymph nodes in pigs

To test the hypothesis that characteristic cytokine responses occur in stim ulated porcine lymph nodes (LNs), lymph node efferent ducts were surgically cannulated. Efferent lymph (EL) leukocytes were collected before and after stimulation of LNs with mitogens [bacterial lipopolysaccharide (LPS) or ph ytohemagglutinin-P(PHA-P)] and antigens [hen egg white lysozyme (HEWL) or p urified protein derivative of tuberculin (PPD)]. Cytokine mRNA expression w as evaluated by quantitative reverse transcription polymerase chain reactio n (Q-RT-PCR). Interleukin (IL)-1 alpha was predominantly produced after all stimuli except for HEWL after which tumour necrosis factor (TNF)-alpha mes sage was dominant. None of the stimuli induced message for IL-2, IL-4 or IL -8. Other cytokine mRNAs were produced in variable amounts and percentage o f overall production of each cytokine message was in the following descendi ng rank: LPS: IL-1 alpha, TNF-alpha, interferon (IFN)-gamma, IL-10, IL-12-p 35, IL-6, IL-12-p40 and TNF-beta; PHA-P: IL-1 alpha, TNF-alpha, IL-10, IFN- gamma, IL-12-p40 and TNF-beta; HEWL: TNF-alpha, IL-1 alpha, IFN-gamma, IL-1 0, IL-6, IL-12-p40, TNF-beta and IL-12-p35 and PPD: IL-1 alpha, IFN-gamma, TNF-alpha and IL-10. Time course response of cytokines revealed early (IL-1 alpha, 10, TNF-alpha) and intermediate (IL-12-p40, TNF-beta, IFN-gamma) re sponses for PHA-P and early (IL-1 alpha, 6, 10, IL-12-p35, IL-12-p40, TNF-a lpha), intermediate (TNF-beta, IFN-gamma) and late (IL-1 alpha, 6) for LPS. Cytokine mRNA response induced by HEWL was early (IL-alpha, IFN-gamma), in termediate (IL-10, IL-12-p40, TNF-beta), late (IL-1 alpha, IL-12-p35) and v ery late (IL-1 alpha, 6, 10, IL-12-p40, TNF-alpha). In Bacillus Calmette-Gu erin (BCG) sensitized pigs, stimulation of LNs with PPD induced message for IL-1 alpha, 10, TNF-alpha and IFN-gamma which peaked at 24 h. Cytokine mRN As varied by stimulus and differed for antibody and cell-mediated immune re sponse. (C) 2000 Elsevier Science B.V. All rights reserved.