T-lymphocyte subsets in the contralateral testis after unilateral blunt testicular trauma in pre-pubertal mice

Although spermatozoa express antigens, they normally do not produce an immunological response because of the blood-testis barrier and the predominance of CD8⁺ T-lymphocytes in the rete testis. Unilateral blunt testicular trauma (UBTT) has been reported to decrease fertility. The present study was designed to evaluate the sub-populations of T-lymphocytes in mice with testicular trauma. Twenty male mice aged 20 days were randomized into control and test groups. At about 70 days of age the contralateral testis was harvested, cell suspensions were prepared, and immunofluorescence staining was performed for detection of CD4⁺ and CD8⁺ T-lymphocytes by flow-cytometry. The ratio of CD8⁺ and CD4⁺ lymphocytes was significantly higher (P < 0.001) in the control mice compared to the UBTT group (1.3 ± 0.3 vs 0.5 ± 0.01). The results suggest that UBTT alters the CD8⁺/CD4⁺ ratio in the contralateral testis, which may have an important bearing on the pathogenesis of infertility in cases of testicular injury. Accepted: 13 October 1998