Role of CD8 Regulatory T Cells versus Tc1 and Tc17 Cells in the Development of Human Graft-versus-Host Disease

Abstract EN

CD8+ T cells that secrete proinflammatory cytokines play a central role in exacerbation of inflammation; however, a new subpopulation of CD8 regulatory T cells has recently been characterized.

This study analyzes the prominent role of these different subpopulations in the development of graft-versus-host disease (GVHD).

Samples from 8 healthy donors mobilized with Filgrastim® (G-CSF) and 18 patients who underwent allogeneic hematopoietic stem cell transplantation (HSCT) were evaluated by flow cytometry.

Mobilization induced an increase in Tc1 ( p < 0.01 ), Th1 ( p < 0.001 ), Tc17 ( p < 0.05 ), and CD8+IL-10+ cells ( p < 0.05 ), showing that G-CSF induces both pro- and anti-inflammatory profiles.

Donor-patient correlation revealed a trend ( p = 0.06 ) toward the development of GVHD in patients who receive a high percentage of Tc1 cells.

Patients with acute GVHD (aGVHD), either active or controlled, and patients without GVHD were evaluated; patients with active aGVHD had a higher percentage of Tc1 ( p < 0.01 ) and Tc17 ( p < 0.05 ) cells, as opposed to patients without GVHD in whom a higher percentage of CD8 Treg cells ( p < 0.01 ) was found.

These findings indicate that the increase in Tc1 and Tc17 cells is associated with GVHD development, while regulatory CD8 T cells might have a protective role in this disease.

These tests can be used to monitor and control GVHD.