Submitted to: Journal of Federation of American Societies for Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: November 3, 2004
Publication Date: March 7, 2005
Citation: Dawson, H.D., Jones, E.A., Beshah, E., Solano Aguilar, G., Urban Jr, J.F. 2005. Increased Th2-associated immunity in ascuris-infected swine treated with retinoic acid. [abstract]. Federation of American Societies for Experimental Biology Journal. 19:A1466. Technical Abstract: Pigs were infected with Ascaris suum and treated with all-trans retinoic acid (ATRA) on d '1, d+1, d+3 of infection. Control or infected pigs were given corn oil or 100 or 1,000 µg/kg ATRA in corn oil by oral gavage. Pigs were sacrificed at 7 and 14 days after infection. The expression of surface antigen on isolated BAL cells at 14 days was determined by flow cytometry. At day 7, there was a dramatic induction of eosinophils (SWC3-/SWC9+) in the BAL cells of pigs infected with A. suum. This increase was significantly augmented by both levels of ATRA. At day 14, here was a significant dose dependent decrease in the proportion of worms found in the proximal vs. distal small intestine in the pigs given ATRA, indicating an enhanced expulsion from the predilection site in the jejunum. A real time PCR array was used to assess localized gene expression. At day 7, uninfected pigs given the low dose of ATRA had increased hepatic mRNA expression of IL4, IL13, and the negative regulators of Th1 cytokine signaling, SOCS1, SOCS3, PIAS1 and PIAS4. Only SOCS3 expression remained higher at 14 days. Infected pigs had higher expression levels of FCER1A, IgE, SOCS3, IL4, IL13 and TPSB1 at 7 days. Infected pigs that received the lowest dose of ATRA had significantly higher levels of IL4, IL13 and TPSB1 than infected pigs; however, FCER1A, IgE and SOCS3 expression were not increased by ATRA. Interestingly, these pigs had higher expression of the Th1-associated markers, IFNG, IL12B and TBX21. This data indicate that ATRA augments a Th2-associated response in swine that enhances parasite expulsion from the intestine.