Morphological study of autologous rosettes (A-RFC).

The morphology of autologous rosette forming cells (A-RFC) has been studied by light and electron microscopy. Autorosette forming cells were obtained from the spleen of adult thymectomized (ATx) or nude mice, and from neonatal thymus grafts during the regeneration phase. Among the autorosettes seen by light microscopy, 76% of them were formed by lymphoid cells which included a high proportion of large lymphocytes (48%). Electron microscopy study performed after isolation of A-RFC by micromanipulation demonstrated that 74% were formed by large lymphoid cells with an immature nucleus. The finding of such large-sized lymphoid cells with immature nuclei is in agreement with our previous results indicating that A-RFC might belong to an immature T cell class.