Identification of Melanoma-reactive CD4+ T-Cell Subsets From Human Melanoma Draining Lymph Nodes

Abstract

Our laboratory has previously demonstrated that melanoma draining lymph node (MDLN) samples from stage III patients contained both CD4+ and CD8+ T cells that can be readily expanded to mediate tumor cell apoptosis in vitro and improve survival in mice bearing human melanoma xenografts. In this study, we investigated whether MDLN T cells contain melanoma-reactive CD4+ T cell compartment and what they are. In order to test this, we performed multi-parametric (11-color and 6-color) FACS analyses to monitor phenotypic and functional property of CD4+ T cells in response to melanoma cell antigen re-exposure. Our results have demonstrated that the antigen re-exposure could result in a generation of CD4+CCR7+CD62L+CD27− T cell subsets with various effector cell-like properties. Within the CD4+CCR7+CD62L+CD27− T cell compartment, in response to antigen re-exposure, some of the cells expressed significantly up-regulated CD40L and/or CXCR5, and some of them expressed significantly up-regulated IL-2 and/or TNF-α. This may suggest the existence of melanoma reactive CD4+ “effector-precursor” cells within the expanded MDLN cells and their differentiation into various effector lineages in response to antigen re-stimulation. Recent clinical trials have demonstrated that effective adoptive cellular immunotherapy (ACI) maybe enhanced by antigen specific CD4+ T cells. Therefore, results of this study may significantly benefit innovative design of ACI that can potentially mediate enhanced and durable clinical responses.

Impact of checkpoint blockade on cancer vaccine–activated CD8+ T cell responses

“…As part of the T cell characterization in this report, CD8B and CXCR5 were shown to mark a subset of memory CD4 T cells, which specialize in supporting antibody-mediated immune responses ( Chevalier, et al, 2011 ). Furthermore, a multi-parametric FACS analysis of melanoma-reactive CD4 T cells from stage III malignant melanoma patients revealed elevated CXCR5 expression in a subset of CD4 T cells with enhanced responsiveness to melanoma cell antigen reexposure ( Zhang et al, 2016 ). In addition to its role as a receptor for T cell priming and B cell activation ( Elgueta, et al, 2009 ), functional expression of CD40 was shown in a recent study by Levin et al (2018 ) to increase IFN-γ secretion and improve the functional properties of human CD8 cells, CD4 cells, and a subset of TILs in melanoma.…”

BG34-200 Immunotherapy of Advanced Melanoma

“…The TdLN-derived T-cell culture and expansion was conducted based on our published protocols [ 18 , 19 , 20 ]. Briefly, one million B16F10 cells were subcutaneously injected into the flanks of donor WT C57BL/6J mice on day 0.…”