MORPHOLOGICAL-CHANGES OF THYMUS IN RETROVIRUS-INDUCED MURINE ACQUIRED-IMMUNODEFICIENCY-SYNDROME (MAIDS)

The possible contribution of the thymus in the setting of-acquired imm unodeficiencies is still questioned. Here we report some new findings regarding a potential involvement of the thymus in mice infected with RadLV-Rs, a viral mixture inducing murine acquired immunodeficiency sy ndrome (MAIDS). Thymi were sequentially removed, weighted and morpholo gically analyzed at different time intervals post-infection. Infection with RadLV-Rs led to a decrease in thymus weight mostly apparent fron t the fourth week. The first changes were seen at the third week as pe rivascular clusters of B-cells at the cortico-medullary junction. The ensuing process of atrophy mainly involved the cortex, while a mixed p opulation of large T- and B-cells filled the medulla. These observatio ns are discussed with regard to the pathological changes occuring in o ther lymphoid and non-lymphoid organs, in the context of the lymphopro liferation and immunodeficiency characterizing the disease, and by com parison with other models of retrovirus-induced immunodeficiencies.