Different phenotypes of CD8+ T cells associated with bacterial load in active tuberculosis.
Tuberculosis is an infectious disease that affects millions of people worldwide with an annual mortality rate of 1.3 million. The mechanisms contributing to the loss of balance of immune responses and progression to active tuberculosis disease are unknown. Although CD4+ and CD8+ T cells and the cytokines they produce are crucial for protection against tuberculosis they have different roles in tuberculosis immunology. The function of CD4+ T cells has been extensively studied; however, less is known about the phenotype and function of CD8+ T cells. This study evaluated the specific expression of IFN-γ, IL-17, IL-10, and TGF-β and ex vivo expression of perforin and granzyme-B by CD8+ T cells from active tuberculosis individuals compared with latent infected individuals and non-latent infected individuals. Tuberculosis responses were correlated with the baciloscopy score. We observed that the presence of IL-10 and TGF-β expression and down-expression of granzyme-B in CD8+ T cells correlated with increased sputum bacillary load in active tuberculosis individuals. These findings provide new insights into the role of CD8+ T cells in Mycobacterium tuberculosis disease.
Department of Microbiology, Immunology, Parasitology and Pathology, Tropical Pathology and Public Health Institute, Federal University of Goiás, Goiânia, Goiás, Brazil.
Bruna Daniella de Souza
BDS
Silva
Department of Microbiology, Immunology, Parasitology and Pathology, Tropical Pathology and Public Health Institute, Federal University of Goiás, Goiânia, Goiás, Brazil.
Monalisa Martins
MM
Trentini
Department of Microbiology, Immunology, Parasitology and Pathology, Tropical Pathology and Public Health Institute, Federal University of Goiás, Goiânia, Goiás, Brazil.
Adeliane Castro
AC
da Costa
Department of Microbiology, Immunology, Parasitology and Pathology, Tropical Pathology and Public Health Institute, Federal University of Goiás, Goiânia, Goiás, Brazil.
Andre
A
Kipnis
Department of Microbiology, Immunology, Parasitology and Pathology, Tropical Pathology and Public Health Institute, Federal University of Goiás, Goiânia, Goiás, Brazil. Electronic address: apkipnis@gmail.com.
Ana Paula
AP
Junqueira-Kipnis
D000328:Adult; D000368:Aged; D058491:Bacterial Load; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D010641:Phenotype; D012307:Risk Factors; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism; D014376:Tuberculosis / Q000276:immunology* / Q000382:microbiology*; D014397:Tuberculosis, Pulmonary / Q000276:immunology / Q000382:microbiology; D055815:Young Adult
D016207:Cytokines
Baciloscopy; CD8+ T cells; Human tuberculosis