Tailored CD4+ lymphocytes expressing human CHAT protein as a novel vasodilator in attenuating RV pressure in PAH animal model

Abstract

ChAT-expressing T cells represent ∼0.01 % of total circulating T lymphocytes in adult wild-type mice. However, we previously reported that systemic infusion of ChAT+ve Jurkat T cells into adult mice elicits vasodilation and instantaneous decline in the mean systolic blood pressure, suggesting potential as a biologic therapeutic to attenuate pathologic increases in pulmonary arterial pressures. We now report that ChAT gene-expressing Jurkat cells dose-dependently decrease right ventricular systolic pressures (RVSP) in hypoxic mice and that transgenic mice with ChAT KO restricted to endothelial cells (KO END/ChAT-/-) exhibit significantly elevated pulmonary arterial pressure and peripheral systemic resistance (compared to WT mice). To rigorously characterize the role of CD4 ChAT+ T cells in regulating pulmonary arterial hypertension (PAH) hemodynamics and molecular signatures, we infused CD4+ ChAT+ve cells (0.5 to 2.0 million cells/animal) into adult PAH mice and noted significant reductions in RVSP within 2-3 min post injection (∼ 50 % reduction). The tailored tail vein injection effect was sustained until the animal was euthanized (30-40 min). Mice KO END/ChAT-/-showed a significant and severe hypoxia-induced PAH phenotype compared to WT adult mice. Tail vein injection of biologically active CD4 ChAT+ve cells into either KO END/ChAT-/-mice with hypoxia-induced PAH or into adult rats with hypoxia/Sugen-induced PAH resulted in significant attenuation of RVP elevations. RNA seq data analysis of human pulmonary endothelial cells (HPAECs) incubated with CD4 ChAT+ve T cells showed significant differential regulation of pathways involved in systemic and pulmonary pressure regulation, NO synthesis/regulation, antioxidant expression, and vasodilation. In conclusion, CD4 ChAT+ve T cells have a unique, vasodilating innate immunity mechanism to augment nitric oxide release and potentially mitigate molecular and genetic pathways involved in PAH pathogenesis.