Characterization of new monoclonal antibodies against porcine lymphocytes: molecular characterization of clone 7G3, an antibody reactive with the constant region of the T-cell receptor d-chains W.-R. Tang a , N. Shioya a , T. Eguchi c , T. Ebata a , J. Matsui a , H. Takenouchi a , D. Honma c , H. Yasue c , Y. Takagaki d , S. Enosawa b , M. Itagaki a , T. Taguchi a , N. Kiyokawa a , H. Amemiya b , J. Fujimoto a, * a Department of Developmental Biology, National Research Institute for Child Health and Development, 3-35-31 Taishido, Setagaya-ku, Tokyo 154-8567, Japan b Department of Innovative Surgery, National Research Institute for Child Health and Development, 3-35-31 Taishido, Setagaya-ku, Tokyo 154-8567, Japan c Genome Research Department, National Institute for Agrobiological Science, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan d Department of Molecular Medicine, Kitasato University School of Medicine, 1-15-1 Kitasato, Sagamihara Kanagawa 288-8555, Japan Received 14 November 2003; received in revised form 9 July 2004; accepted 26 August 2004 Abstract A battery of mouse monoclonal antibodies (mAbs) reactive with porcine peripheral blood (PB) leukocytes was generated. Among the mAbs, 6F10 was found to react probably with cluster of differentiation (CD)8 a-chain, while 7G3 and 3E12 were found to recognize gd T-cells, as revealed by two-color flow cytometric and immunoprecipitation studies. 7G3 was shown to react with the constant (C) region of the T-cell receptor (TCR) d-chain by the following facts: (1) 7G3 immunoprecipitated full- length TCR d-chain protein fused with glutathione S-transferase (GST) produced by Esherichia coli and (2) 7G3 reacted with TCR d-chain expressing Cos-7 cells transfected with either full-length or N-terminal deleted mutant cDNA, but did not react with Cos-7 cells transfected with C-terminal deleted mutant TCR d-chain cDNA. All three mAbs produced high-quality immunostaining results on frozen sections, revealing a distinct distribution of gd T-cells and CD8 + cells. This report precisely www.elsevier.com/locate/vetimm Veterinary Immunology and Immunopathology 103 (2005) 113–127 Abbreviations: CD, cluster of differentiation; PB, peripheral blood; C region, constant region; PE, phycoerythrin; GST, glutathione S- transferase; HRP, horseradish peroxidase * Corresponding author. Tel.: +81 3 3487 9669; fax: +81 3 3487 9669. E-mail address: jfujimoto@nch.go.jp (J. Fujimoto). 0165-2427/$ – see front matter # 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.vetimm.2004.08.018