Lymphocyte-specific inducible expression of potassium channel beta subunits

Many studies have shown that voltage-gated potassium (Kv) channel activity is essential for T-lymphocyte proliferation. The IL-2-inducible neuroimmune gene, I2rf5 is the mouse homologue of the rat Kvβ2 subunit. In this study we show that in addition to constitutive expression in adult murine brain, expression of Kv channel subunits β1.1 and β2.1 is inducible in a cloned T-helper cell line stimulated with IL-2 and in normal murine splenocytes stimulated with Con A or LPS. This expression pattern appears to be lymphocyte specific, because stimulated fibroblasts and vascular smooth muscle cells do not express Kvβ channel subunit mRNA. These observations suggest that Kvβ subunit expression is tissue specific and inducible in stimulated lymphocytes. Because Kvβ subunits modulate K⁺ channel activity, the inducible and variable expression of these subunits in lymphocytes may represent an additional regulatory mechanism for lymphocyte proliferation.