Description of CD8⁺ Regulatory T Lymphocytes and Their Specific Intervention in Graft-versus-Host and Infectious Diseases, Autoimmunity, and Cancer

Figure 2

Participation of CD8⁺ Treg lymphocytes in infectious diseases. In an infection with human immunodeficiency virus (HIV), CD8⁺ T lymphocyte has a phenotype CD28⁻CD127^loCD39⁺ inhibiting lymphocyte proliferation, which is probably related to the immunodeficiency shown during the disease. In a parasitic infection as leishmaniasis, the persistence of the parasite partly depends on the existence of CD8⁺ Treg lymphocytes expressing CTLA-4 and producing IL-10, which results in the prevalence of the disease. During immunosuppression situations, there is an increase in the population of IL-10-producing CD8⁺FoxP3⁺ Treg lymphocytes that inhibit CD4⁺ T cell proliferation, promoting infection by Epstein-Barr virus. The low protection of bacillus Calmette-Guérin vaccine is attributed factors as CD8⁺CD25⁺CD39⁺ Treg lymphocytes that inhibit the proliferation of CD4⁺ T lymphocytes producing Th1 cytokines as IFN-γ, necessary to activate other cell lines against mycobacteria.