STUDY OF APOPTOSIS IN SPERMATOGENIC CELLS OF MICE INFECTED BY TOXOPLASMOSIS
Hala Said Salem1 and Zeinab Mahmoud Gebaly2
Departments of Parasitology1 and Histology2, Faculty of Medicine, Al- Azhar University for Girls
Infection with the obligate intracellular protozoan Toxoplasma gondii leads to lifelong persistence of the parasite in its mammalian hosts including humans. Apoptosis plays crucial roles in the interaction between the host and the parasite. Objective of the study: to investigate the influence of infections with Toxoplasma gondii on the state of apoptosis in spermatogenic cells of mice. Methods: Three groups were tested each 10 males, 7 weeks old albino mice. Group (I): control group not infected mice. Group (II): mice infected intraperitoneally by103 trophozoites T. gondii RH strain and Group (III): mice infected intraperitoneally by 104 trophozoites, RH strain. 10 days post infection the mice were sacrificed and the testes were dissected and blocked in paraffin. Hematoxylin and eosin (H&E) and Periodic acid schiff stain (PAS) were applied to study the histological changes. Immunohistochemistry stain for antiapoptotic Bcl-2 protein marker and apoptotic protein marker Fas were used to stain the testes sections of different groups. Results: H& E stain showed few changes in the seminiferous tubules of group (II) with some vacuolation of spermatocytes and no changes in Leydig cells. Group (III) showed variation in sizes of seminiferous tubules with disruption in their epithelial lining which appeared to be lined by single or few layers, leydig cells were also affected in this group and showed decrease in number and disruption. PAS stain showed significant positive result of infected group II & III in comparison to control group (P <0.05 and P= 0.00 respectively). The expression of Bcl-2 had no significant difference between normal control group and group (II) while minimum expression of Bcl-2 was noticed in group (III) with significant statistical difference (P< 0.001). Fas expression showed significant difference (P= 0.00) between group (III) and the control, while no significant difference was noticed between group (II) and control (P= 0.23). Conclusion: Toxoplasma gondii enhanced apoptosis of mice spermatogenic cells under the control of Fas apoptotic protein.