Short communication Identification of key immune mediators regulating T helper 1 responses in swine Harry D. Dawson a,1 , Atabak R. Royaee b,1,2 , Sandra Nishi b,3 , Daniel Kuhar 2 , William M. Schnitzlein c , Federico Zuckermann c , Joseph Urban Jr. a , Joan K. Lunney b,* a Nutrient Requirements and Functions Laboratory, Beltsville Human Nutrition Research Center, USDA, Bldg. 307C, Room 213, BARC-East, Beltsville, MD 20705, USA b Animal Parasitic Disease Laboratory, Animal and Natural Resources Institute, Agricultural Research Service, USDA, Bldg. 1040, Rm. 104, BARC-East, Beltsville, MD 20705, USA c Department of Veterinary Pathobiology, University of Illinois, Urbana, IL 61802, USA Received 31 December 2003; received in revised form 1 March 2004; accepted 10 March 2004 Abstract This publication describes the cloning of full or partial length sequences for pig TBX21 (T-bet), MYD88, ICSBP1, CD8A (CD8a), CD8B (CD8b), and CD28 cDNAs. Real-time PCR assays have been developed for the relative quantitation of these products as well as previously characterized transcripts that encode exon A-containing CD45, HLX1, IRF1, STAT1 and RPL32. When used for examining temporal immune gene expression in the liver of Toxoplasma gondii infected pigs, the positive regulators of Th1 responses, IRF1, MYD88, and STAT1, were found to be expressed prior to the simultaneous upregulation of interferon gamma (IFNG), HLX1 and TBX21 gene expression. In contrast, in the mesenteric lymph node (MLN), only expression of IRF1 and IFNG was significantly upregulated. Based on their demonstrated utility in establishing an immune response pathway, these PCR assays should be valuable additions to our swine immune toolkit. # 2004 Published by Elsevier B.V. Keywords: Swine; Cytokine gene regulation; T helper 1 immunity; Protozoan parasite Understanding the regulated synthesis of genes and proteins controlling adaptive immune responses is essential for improving methods to prevent infectious diseases, decrease associated pathology, and design new therapeutics and vaccines. Our previous exam- ination of this process via real-time PCR assays demonstrated that infection of swine with the intra- cellular parasite Toxoplasma gondii elicited a Th1- associated response dominated by interferon-gamma (IFNG) gene expression whereas the extracellular parasite, Ascaris suum, induced a Th2-type response characterized by enhanced IL4 and IL13 gene expres- sion (Dawson et al., submitted). At that time, quanti- tation of transcripts encoding components of upstream Veterinary Immunology and Immunopathology 100 (2004) 105–111 * Corresponding author. Tel.: þ1-301-504-9368; fax: þ1-301-504-5306. E-mail address: jlunney@anri.barc.usda.gov (J.K. Lunney). 1 The first two authors contributed equally to this work. 2 Present address: Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA 02115, USA. 3 Present address: Departamento de Medicina Veterina ´ria Pre- ventiva e Sau ´de Animal, Faculdade de Medicina Veterina ´ria e Zootecnia, Universidade de Sa ˜o Paulo, Sa ˜o Paulo, Brazil. 0165-2427/$ – see front matter # 2004 Published by Elsevier B.V. doi:10.1016/j.vetimm.2004.03.006