Molecular cloning and expression profile analysis of interleukin-10 and interleukin-18 cDNA of Indian water buffalo (Bubalus bubalis) Avinash Premraj a , E. Sreekumar a , Binita Nautiyal b , T.J. Rasool c, * a Animal Biotechnology Laboratory, Rajiv Gandhi Center for Biotechnology (RGCB), Jagathy, Thycaud PO, Trivandrum 695014, Kerala, India b Department of Animal Science, M.J.P. Rohilkhand University, Bareilly, Uttar Pradesh 243006, India c Indian Veterinary Research Institute (IVRI), Kumaon Campus, Mukteswar, Nainital District, Uttaranchal 263138, India Received 17 February 2005; received in revised form 13 May 2005; accepted 26 May 2005 Abstract The cDNAs encoding the interleukin-10 and interleukin-18 of Indian water buffalo (Bubalus bubalis) were cloned and sequenced. A 537 bp IL-10 cDNA fragment and a 623 bp IL-18 cDNA fragment were amplified by reverse transcriptase polymerase chain reaction (RT-PCR) from concanavalin A stimulated splenocytes. Sequence analysis of these cytokines revealed high level conservation at nucleic acid and protein level. Both these cytokines also showed strict conservation in the predicted secondary structure and critical amino acid residues compared to the ruminant homologues. Basal level expression of both IL-10 and IL-18 was observed in liver, lung and spleen. The expression level of IL-10 was not affected by mitogenic stimulation, whereas IL-18 was up regulated upon stimulation. The availability of these cytokine molecules will aid in the study of their role in the immunology and pathogenesis of infections in water buffalo. # 2005 Elsevier B.V. All rights reserved. Keywords: Buffalo; Cytokine; IL-10; IL-18 1. Introduction Availability of species-specific molecular tools is highly desirable for developing proper health care strategies for livestock species, especially for large animals of developing countries. The Water Buffalo (Bubalus bubalis) is an important dairy animal of South and South East Asia. They contribute 56% of the total milk production of India (FAOSTAT, 2003). In spite of their hardier nature and adaptation to tropical conditions, buffaloes are susceptible to many of the common diseases that affect cattle. Investiga- tions on the immune mechanism of buffaloes at the molecular level have been very limited, and there are no agents specifically available for the diagnosis and prevention of diseases in buffalo. There are reports www.elsevier.com/locate/vetimm Veterinary Immunology and Immunopathology 107 (2005) 337–347 * Corresponding author. Tel.: +91 5942 286346; fax: +91 5942 288347. E-mail address: tjrasool@gmail.com (T.J. Rasool). 0165-2427/$ – see front matter # 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.vetimm.2005.05.007