Background and Aim: Hydatidosis is a chronic zoonotic parasitic disease with global distribution, which affects the immune system. Inhibition of CD28 expression and elevation o inhibitory receptor like TIM3 induce T cells toward senescence differentiation, and causes immune responses to be adjusted negatively during the chronic infection. The purpose of the present study was to investigate expression of CD28 and TIM3 in CD8+ T cell population and IL-35 and IL-37 in serum of patients with hydatid cysts. Methods: The PBMCs of patients with hydatid cysts (before and after surgery) and healthy subjects (control) were separated. The expression of CD8, CD28, CD3, and TIM3 were examined with the flow cytometry method. The inflammatory cytokines were also examined with the ELISA method after the subjects’ blood serums were collected. Results: The results demonstrated a significant decreased in expression of TIM3 in the hydatidosis patients before surgery (P<0.05). CD8+CD28- cell population in the group of patients exhibited a significant decrease before surgery (P<0.05) in contrast to the control group. IL-35 in the two groups of patients, before and after surgery, exhibited a significant increase (P<0.05). Conclusion: The expression of T cells senescence markers decreased in patients with hydatid cysts and hydatidosis could partially inhibits the senescence T cells induction. Identification the senescence preventing mechanisms could reveal new therapeutic ways to prevent age-related diseases such as cancer.