polyomavirus bk-specific cd4+ t cells response to vp1 stimulation in kidney transplant recipients

Reactivation of polyomavirus bk (bkpyv) is related to reduction of t cells response in kidney transplant recipients (ktrs). here, we examined the differentiation of cd4+ t cells subsets in response to bkpyv ktrs, using the bkpyv vp1 (viral capsid protein 1) as a stimulator.we categorized our samples into three distinct groups: 1. reactive bkpyv (bkpyv+), 2. non-reactive (bkpyv-) ktrs and 3. healthy controls. bkpyv- ktrs and healthy controls stimulated with vp1 and bkpyv+ unstimulated with vp1. the human cd4+ t cells was stimulation with vp1-ag. the proportion of cd4+ t lymphocytes and their various subsets, including naive t cells, central memory t cells (tcm), and effector memory t cells (tem) was measured using flowcytometry.bkpyv- ktrs vp1+ indicated significantly lower tcm cd4+ t cells in contrast with both bkpyv+ ktrs vp1-, and healthy controls vp1+. this indicates that vp1 stimulation may reduce tcm cell levels in these patients. the percentage of tem in the bkpyv- ktrs vp1+ group was significantly less prevalent than the bkpyv+ ktrs vp1- group. the percentage of tem cells in bkpyv+ ktrs vp1- was significantly lower than the healthy controls vp1+. stimulation with vp1 protein significantly increased the frequency of cytotoxic cd4+ t cells in bkpyv- ktrs vp1+ compared to bkpyv+ ktrs vp1-.the present research has shown that the vp1 stimulation of cd4+ t cells can induce cytotoxic cd4+ t cells responses that may help overcome bkpyv infection in ktrs. however, vp1 stimulation may also differentially affect tcm and tem cd4+ t cells subsets.