Changes in the expression of potassium channels during mouse T cell development.
In this report we have combined the whole-cell electrophysiological recording technique with flow microfluorometry to isolate phenotypically defined thymocytes and T lymphocytes. Results obtained showed that J11d-/Lyt-2-/L3T4- cells express none or very few delayed rectifier K+ channels, whereas most other Lyt-2-/L3T4- cells, as well as typical cortical thymocytes (Lyt-2+/L3T4+), do express K+ channels. Mature (Lyt-2+/L3T4- or Lyt-2-/L3T4+) thymocytes, which are heterogeneous for J11d expression, were also found to be heterogeneous for K+ channel expression. Consistent with this finding was the observation that the cortisone-resistant subpopulation of thymocytes, which express low levels of J11d, were enriched for cells expressing low levels of K+ channels. Mature phenotype peripheral T lymphocytes expressed very low levels of K+ channels, but upon activation with Con A were found to express high levels of K+ channels. The results suggest that K+ channel expression in T cells is developmentally regulated. Increased expression of the channel is induced in response to mitogenic signals throughout the T cell lineage. Expression of the channel, therefore, serves as a useful marker in defining steps in the T cell differentiation pathway.
D000818:Animals; D002454:Cell Differentiation; D003208:Concanavalin A / Q000494:pharmacology; D004553:Electric Conductivity; D005260:Female; D007399:Interphase; D007473:Ion Channels / Q000378:metabolism*; D007518:Isoantibodies / Q000032:analysis; D008213:Lymphocyte Activation / Q000187:drug effects; D051379:Mice; D008810:Mice, Inbred C57BL; D011188:Potassium / Q000378:metabolism*; D013601:T-Lymphocytes / Q000166:cytology*
D007473:Ion Channels; D007518:Isoantibodies; C029805:Lyt antibodies; D003208:Concanavalin A; D011188:Potassium