Background: Hydatid cyst develops in many organs, mostly in liver and lungs. Immune responses against hydatidosis comprises of various mechanisms of innate and adaptive immunity. In recent years the importance of innate immune responses and in particular, pattern recognition receptors (PRRs) has been recognized as an essential mechanisms for development of an effective immune response. PRRs are the main sensors of pathogen and danger signals in innate immunity. Toll like receptors (TLRs) are the most studied and best characterized PPRs which are responsible for sensing pathogen associated molecular patterns (PAMPs). The role of TLRs in the molecular mechanisms underlying the pathogenesis and immunity in helminths infection has not clearly been defined. Therefore in the present study, we aimed at dissecting the role of hydatid cyst derived antigens on TLRs expression in immune cells of young lambs. Methods: In this study we focused on the expression levels of two important ovine TLRs transcripts, namely TLR2 and TLR4 in a culture of ovine lymphocytes exposed to different concentrations of Excretory-Secretory(ES) antigens of hydatid cysts in a time and dose dependent manner. Blood samples were taken from healthy young lambs and after isolation of peripheral blood mononuclear cells (PBMC), the cells were cultured with different concentrations(50μg/ml &100μg/ml) of ES antigens (antigens were extracted and concentrated according to the standard protocols) in different time points. Then, total RNA was isolated from the cell pellets and cDNA was synthesized using Oligo dT primers. Afterwards, the primer pairs for TLR2, TLR4 as target genes and GAPDH as housekeeping and calibrator gene were optimized in a gradient RT-PCR experiment. Subsequently, qPCR analysis was set up to quantify and compare the relative expression levels of TLR2 and TLR4 transcripts in PBMC of antigen treated versus control (untreated) samples.Result: Statistical analysis showed an up-regulation of TLR2 and TLR4, in treated compared to untreated control group. Conclusion: the results presented in this study, can shed more lights to the insight mechanisms behind the molecular immuopathogenesis of hydatidosis which might eventually pave the way for designing novel and more effective therapeutic as well as preventive strategies.

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