Immune activation and regulatory T cells in Mycobacterium tuberculosis infected lymph nodes

• Published in: BMC immunology 2018-11, Vol.19 (1), p.33-33, Article 33
• Main Authors: Sahmoudi, Karima, Abbassi, Hassan, Bouklata, Nada, El Alami, Mohamed Nouredine, Sadak, Abderrahmane, Burant, Christopher, Henry Boom, W, El Aouad, Rajae, Canaday, David H, Seghrouchni, Fouad
• Format: Article
• Language: English
• Subjects: activation; Antigens; Biopsy; CD38 antigen; CD4 antigen; Cell activation; Cell differentiation; conventional T cell; Cytokines; Histocompatibility antigen HLA; HIV; Human immunodeficiency virus; Immunological memory; Immunoregulation; Infections; Interleukin 2; Leukocytes (mononuclear); Lymph node; Lymph nodes; Lymphadenitis; Lymphatic system; Lymphocytes; Lymphocytes T; Memory cells; Mycobacterium tuberculosis; Peptides; Peripheral blood mononuclear cells; Phenotypes; Software; Statistical analysis; Treg cells; Tuberculosis; Tumor necrosis factor-α; γ-Interferon
• ISSN: 1471-2172; 1471-2172
• DOI: 10.1186/s12865-018-0266-8

Lymph node tuberculosis (LNTB) is the most frequent extrapulmonary form of tuberculosis (TB). Studies of human tuberculosis at sites of disease are limited. LNTB provides a unique opportunity to compare local in situ and peripheral blood immune response in active Mycobacterium tuberculosis (Mtb) disease. The present study analysed T regulatory cells (Treg) frequency and activation along with CD4+ T cell function in lymph nodes from LNTB patients. Lymph node mononuclear cells (LNMC) were compared to autologous peripheral blood mononuclear cells (PBMC). LNMC were enriched for CD4+ T cells with a late differentiated effector memory phenotype. No differences were noted in the frequency and mutifunctional profile of memory CD4+ T cells specific for Mtb. The proportion of activated CD4+ and Tregs in LNMC was increased compared to PBMC. The correlation between Tregs and activated CD4+ T cells was stronger in LNMC than PBMC. Tregs in LNMC showed a strong positive correlation with Th1 cytokine production (IL2, IFNγ and TNFα) as well as MIP-1α after Mtb antigen stimulation. A subset of Tregs in LNMC co-expressed HLA-DR and CD38, markers of activation. Further research will determine the functional relationship between Treg and activated CD4+ T cells at lymph node sites of Mtb infection.