Interleukin 2 receptor expression and interleukin 2 production in exponentially growing T cells: major differences betweenin vivoandin vitroproliferating T lymphocytes

摘要

AbstractIn the present study we have assessed the growth requirements forin vivoproliferating mature T cells. For that purpose we have selected experimental approaches which allow the study of exponential growthin vivoof a major fraction of T cells, and make it possible to obtain large numbers of T cells in cycle. Two types of growing T cell populations were used: peripheral T lymphocytes, proliferating exponentially after transfer into syngeneic athymic nude mice, and activated T cells in lymph nodes of normal mice draining the site of oxazolone administration. The results obtained show that mature T cell growthin vivois not accompanied by expression of high‐affinity interleukin 2 (IL2) receptor in the majority of activated cells, is not abrogated byin vivoadministration of anti‐IL2 receptor antibodies or enhanced by thein vivoinjection of recombinant IL2, and thatin vivogrowing T cells do not produce detectable amounts of IL2, as evaluated functionally by limiting dilution assays or the presence of IL2 mRNA, detected by Northern blots orin situhybridization. The presented data thus indicate that the rules known to apply to T cell activation and proliferationin vitrodiffer from those used byin vivogrowing T lymphocytes, at least in the two systems stud