Cytokine mRNA expression in the spleen, thymus, tonsil, popliteal and mesenteric lymph nodes of neonatal, 1-month-old and adult pigs was compared. The mRNA expression of interleukin (IL)-1β, 6, 10, 12p35, 12p40, 18, interferon (IFN)-γ and tumor necrosis factor (TNF)-α in the lymphatic organs was investigated by semi-quantitative RT-PCR. Stronger IL-1β mRNA expression was observed in the 1-day-old and 1-month-old piglets than in the adult pigs. The expression of IL-6 mRNA in the 1-day-old and 1-month-old tonsil tended to be stronger than in the adult pigs. The expression of IL-1β and IL-6 mRNA may reflect an inflammatory reaction against the exo- and endogenous foreign bodies occurring in the lymphatic organs, especially in the tonsil, of neonatal piglets. The expression of IL-10 mRNA in the 1-day-old spleen, popliteal and mesenteric lymph nodes were stronger than in the adult pigs, while the expression of IFN-γ mRNA in the 1-day-old lymph nodes were weaker than in the adult pigs. The results suggest that the expression of mRNAs for cytokines related with the cellular immunity in the neonatal piglets tended to be weaker than in the adult pigs. Oligo-nucleotide probes were newly designed for the detection of porcine IL-18 mRNA in tissue sections by in situ hybridization, and IL-18 mRNAs were successfully detected in the paraffin-embedded sections. (Toxico-pathology Section, Department of Safety Research TEL +81-29-838-7818)
Reference:
Mikami et al. (2002) Vet. Immunol. Immunopathol. 90:205-209.
