Polyomavirus BK-Specific CD4+ T Cells Response to VP1 Stimulation  in Kidney Transplant Recipients

Nasrin Noshadi; Ramin Yaghobi; Afsoon Afshari; Mohsen Forouzanfar; Saeede Soleimanian

doi:10.18502/ijaai.v23i3.15637

Nasrin Noshadi Department of Biology, Marvdasht Branch, Islamic Azad University, Marvdasht, Iran
Ramin Yaghobi Shiraz Transplant Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
Afsoon Afshari Shiraz Nephro-Urology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
Mohsen Forouzanfar Department of Biology, Marvdasht Branch, Islamic Azad University, Marvdasht, Iran
Saeede Soleimanian Allergy Research Center, Shiraz University of Medical Sciences, Shiraz, Iran

DOI: https://doi.org/10.18502/ijaai.v23i3.15637

Keywords: CD4 T cell; Kidney transplant; Polyomavirus BK; VP1 protein

Abstract

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.