lewis-x-antigen and Latent-Tuberculosis

Protective host responses in those exposed to or infected with tuberculosis (TB) is thought to require a delicate balance between pro-inflammatory and regulatory immune responses. Myeloid-derived suppressor cells (MDSCs), regulatory cells that dampen T-cell function, have been described in cancer and other infectious diseases but there are limited data on their role in TB.. Peripheral blood was obtained from patients with active pulmonary TB and participants with presumed latent TB infection (LTBI) from Cape Town, South Africa. MDSC frequency was ascertained by flow cytometry. Purified MDSCs were used to assess (i) their suppressive effect on T-cell proliferation using a Ki67 flow cytometric assay and (ii) their effect on mycobacterial containment by co-culturing with H37. Collectively, these data suggest that circulating MDSCs are induced during active TB disease and can functionally suppress T-cell proliferation and subvert mycobacterial containment. These data may inform the design of vaccines and immunotherapeutic interventions against TB but further studies are required to understand the mechanisms underpinning the effects of MDSCs.

Topics: Adult; Cell Proliferation; Coculture Techniques; Female; Granulocytes; HLA-DR Antigens; Humans; Hydrolases; Latent Tuberculosis; Lewis X Antigen; Macrophages; Male; Microbial Viability; Middle Aged; Mycobacterium tuberculosis; Myeloid-Derived Suppressor Cells; Preliminary Data; Sialic Acid Binding Ig-like Lectin 3; South Africa; T-Lymphocytes; Tuberculosis, Pulmonary