Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 10 3 2015 10 17 498 504 EN Hassan BORJI Dept. of Pathobiology, School of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran Alireza HAGHPARAST Dept. of Pathobiology, School of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran Nooshinmehr SOLEIMANI Dept. of Pathobiology, School of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran Mohammad AZIZZADEH Dept. of Clinical Science, School of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran Mohammad Hossein NAZEMSHIRAZI Central Laboratories of Khorasan Razavi Veterinary Organization, Mashhad, Iran 2015 10 14 2015 10 14 Background: Recognition of helminth-derived pathogen associated molecular patterns (PAMPs) by pattern recognition receptors (PRRs), including toll like recep­tors (TLRs) is the first step towards initiating anti–helminth immune re­sponses. Methods: Using somatic antigens of Ostertagia occidentalis, an important abomasal parasite of ruminants, the expression of ovine TLR2 and TLR4 in peripheral blood mononuclear cells (PBMCs) was analyzed by real-time quatitative reverse-transcrip­tion polymerase chain reaction (qRT-PCR). Somatic antigens of O. occidentalis were prepared to stimulate ovine PBMCs in a time and dose dependent manner. Results: A high expression of TLR2 and TLR4 was observed in PBMCs cultured with somatic antigens of the parasites specially when PBMCs were cultured with 100 µg/ml of somatic antigens and incubated for 2h. Up-regulation of TLR2 expres­sion was more pronounced and evident in our study. Conclsusion: Somatic antigens of O. occidentalis have immunostimulatory and domi­nant role on peripheral immune cells. This study provide for the first time evidence of induction of TLRs in ovine PBMCs by somatic antigen of O. occidentalis https://ijpa.tums.ac.ir/index.php/ijpa/article/view/317 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/317/292