The dose-dependent effects of cytokines (IL-2, IL-7, and IL-15), which have a common g-chain, on mRNA expression of U2afll4 and GFi1 genes involved in regulation of alternative splicing of the Ptprc gene, have been investigated in vitro using T-lymphocyte cultures with different degrees of differentiation. IL-2, IL-7, and IL-15 caused a similar unidirectional inhibitory effect of various severity on restimulated CD45RO+ T-cells exposed to an antigen-independent activation; they caused a dose-dependent decrease of the U2af1l4 gene expression, and an increase of Gfi1 gene expression. This may suggest formation of active forms of the CD45 receptor, and also limitation of the formation of low-molecular short splice variants of the CD45RO receptor. Under conditions of antigen-independent stimulation of naive CD45RA+-cells rIL-7 and IL-15 exhibited opposite effects on U2af1l4 and Gfi1 gene expression. The increase of IL-7 concentrations in the incubation medium of naive cells was accompanied by a decrease in expression of both genes. IL-15 IL-7 exhibited opposite effects. Cytokines possessing a common g-chain (IL-2, IL-7, and IL-15) prevented antigen-independent differentiation of naive T-cells, by preventing the formation of polyclonal "surrogate" cells. In general, the study of the molecular mechanisms of genetic control determining homeostatic processes of T-cells in response to exposure to antigenic or non-antigenic treatments may be important for construction of a general model of self-maintenance and differentiation of immune cells.
Na restimulirovannye CD45RO+ T-kletki, podvergnutye antigen-nezavisimoĭ aktivatsii, éti tsitokiny v tselom okazyvali odnonapravlennoe deĭstvie. Dozozavisimoe podavlenie ékspressii gena U2af1l4 i uvelichenie ékspressii Gfi1 mozhet svidetel'stvovat' ob obrazovanii aktivnykh form retseptora CD45 i ogranichenii formirovaniia nizkomolekuliarnykh korotkikh splaĭs-variantov retseptora CD45RO. V usloviiakh antigen-nezavisimoĭ stimuliatsii naivnykh CD45RA+-kletok, deĭstvie rIL-7 i IL-15 na ékspressiiu genov U2af1l4 i Gfi1 nosit raznonapravlennyĭ kharakter. Uvelichenie kontsentratsii IL-7 v srede inkubatsii naivnykh kletok soprovozhdaetsia snizheniem ékspressii oboikh genov. Éffekty IL-15 protivopolozhny deĭstviiu IL-7. Tsitokiny, imeiushchie obshchuiu g-tsep' (IL-2, IL-7 i IL-15), predotvrashchaiut antigen-nezavisimuiu differentsirovku naivnykh T-kletok, prepiatstvuia obrazovaniiu poliklonal'nykh “surrogatnykh” kletok. V tselom, issledovanie mekhanizmov molekuliarno-geneticheskogo kontrolia, obespechivaiushchikh protsessy gomeostaza T-kletok v otvet na vozdeĭstvie antigennoĭ i ne antigennoĭ prirody, mozhet imet' vazhnoe znachenie pri postroenii obshcheĭ modeli differentsirovki i samopodderzhaniia immunokompetentnykh kletok.
Keywords: T-cells; activation; alternative splicing; cytokines; gene expression.