Human testis in organotypic culture: application for basic or clinical research.

Background: Over recent decades, recurring efforts have been devoted to developing testicular cell or tissue cultures for basic and clinical research. However, there remains much confusion, particularly concerning the fate of human germ cells in culture.

Objective: To reassess the status of human testicular cell types as well as the ability of germ cells to divide and differentiate in organotypic culture.

Methods: Human testicular fragments were maintained for 2 weeks in culture. The viability and functionality of testicular cells were assessed using light and electronic microscopy, apoptotic cell labelling, 5-bromo-2'-deoxyuridine (BrdU) incorporation, immunohistochemistry and quantitative PCR against specific cell markers.

Results: A gradual loss of meiotic and post-meiotic germ cells occurred throughout the culture period, irrespective of the presence of gonadotrophins. However, all germ cell types remained traceable for up to 16 days, some still dividing and differentiating at a rate compatible with the in vivo situation. Good maintenance of the general architecture of the explants associated with clearly quantifiable levels of several somatic cell markers was observed.

Conclusion: Although this culture model is clearly unsuitable for preparing germ cells for therapeutic purposes, it does represent a most valuable tool for testing the effects of biological and chemical agents on testicular tissue.