CCR2 regulates the immune response by modulating the interconversion and function of effector and regulatory T cells

E Bakos, CA Thaiss, MP Kramer, S Cohen… - The Journal of …, 2017 - journals.aai.org
E Bakos, CA Thaiss, MP Kramer, S Cohen, L Radomir, I Orr, N Kaushansky, A Ben-Nun…
The Journal of Immunology, 2017journals.aai.org
Chemokines and chemokine receptors establish a complex network modulating immune cell
migration and localization. These molecules were also suggested to mediate the
differentiation of leukocytes; however, their intrinsic, direct regulation of lymphocyte fate
remained unclear. CCR2 is the main chemokine receptor inducing macrophage and
monocyte recruitment to sites of inflammation, and it is also expressed on T cells. To assess
whether CCR2 directly regulates T cell responses, we followed the fates of CCR2−/− T cells …
Abstract
Chemokines and chemokine receptors establish a complex network modulating immune cell migration and localization. These molecules were also suggested to mediate the differentiation of leukocytes; however, their intrinsic, direct regulation of lymphocyte fate remained unclear. CCR2 is the main chemokine receptor inducing macrophage and monocyte recruitment to sites of inflammation, and it is also expressed on T cells. To assess whether CCR2 directly regulates T cell responses, we followed the fates of CCR2−/− T cells in T cell–specific inflammatory models. Our in vitro and in vivo results show that CCR2 intrinsically mediates the expression of inflammatory T cell cytokines, and its absence on T cells results in attenuated colitis progression. Moreover, CCR2 deficiency in T cells promoted a program inducing the accumulation of Foxp3+ regulatory T cells, while decreasing the levels of Th17 cells in vivo, indicating that CCR2 regulates the immune response by modulating the effector/regulatory T ratio.
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