what does "immunologically competent cells " mean with reference to the interstitial spaces of testis

Immune cells are regular components of the male reproductive tract of mammals, including humans. Whereas interactions between the testis and the immune system have been a source of considerable curiosity and remained obscure for many years, there is now compelling evidence that testicular immune cells play a key role in testicular function. Located in the interstitial compartment of the normal, unaffected testis they are implicated in the mechanisms that make the testis an immunologically privileged site where germ cells are protected from autoimmune attack and foreign tissue grafts may survive for extended periods. With regard to normal development and function of the testis, both pro- and anti-inflammatory cytokines are involved in the complex interactions between testicular somatic cells and resident as well as circulating immune cells. The same cytokines experience considerable upregulation during the induction and amplification of cellular immune responses, illustrating that the testicular environment does not preclude inflammatory reactions and subsequent disturbance of spermatogenesis and steroidogenesis. Notably, active immunization with testicular tissue or adoptive transfer of specific T lymphocytes causes autoimmune orchitis in experimental animals. In men, infection and inflammation of the reproductive tract including the testes are widely accepted as important aetiological factors of infertility. Whereas symptomatic orchitis due to bacterial or viral infections is considered to be rare, a high prevalence of asymptomatic testicular inflammatory reactions is observed among infertile males.