Poster Presentation The Australasian Society for Immunology 2017 Annual Scientific Meeting

Changes in peripheral T-cell subsets during Tuberculosis-Diabetes Co-morbidity (#284)

Mosa Selamolela 1 , Happy Tshivhula 1 , Léanie Kleynhans-Cornelissen 1 , Carine Kunsevi-Kilola 1 , Gerhard Walzl 1 , Katharina Ronacher 1 2
  1. DST/NRF Centre of Excellence in Biomedical Tuberculosis Research and SA MRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosh University, Cape Town, Western Cape, South Africa
  2. Mater Research Institute- The University of Queensland, Translational Research Institute, Woolloongabba, Brisbane, Queensland, Australia

The prevalence of type 2 diabetes (DM2) continues to increase rapidly particularly in developing countries where tuberculosis (TB) is endemic.DM2 patients are three times more likely to develop active TB and generally respond poorly to TB treatment. Studies have demonstrated that TB-DM co-morbidity is characterized by elevated systemic cytokine concentrations, where coincident DM altered the cellular subset distribution of T cells in active TB patients and latently infected individuals. We investigated, for the first time, the T cells subsets in healthy controls and TB patients with and without DM in a South African population.

Peripheral blood mononuclear cells (PBMCs) from age and gender matched TB-DM (n=21), TB (n=18), DM patients (n=13) and healthy controls (HCs; n=8) were collected prior to commencement of treatment (baseline, BL), at month two (M2) and month 6 (end of treatment; M6). PBMCs were stained with antibodies (CD3, CD4, CD38, CD197, CD45RA and CD45RO) to characterize CD4+ and CD8+ Tnaïve, TCM, TEM and TEMRA T cells phenotypically by flow cytometric analysis.

The frequency of the total CD4+ TCM cells was higher in the DM and HC group compared to the TB and TB-DM groups at BL. In TB-DM patients, the total CD4+ TCM cells increased and the CD4+ Tnaïve cells decreased during TB treatment. The frequency of CD8+ Tnaive cells was lower at M6 compared to BL in TB-DM. Furthermore, the frequency of activated CD4+ Tnaïve cells was higher at M2 compared to BL in TB patients. In both TB and TB-DM groups, the activated CD8+ Tnaive cells increased and TEMRA cells decreased during TB treatment.

The relative percentages of peripheral cell populations are altered in TB patients compared to DM and HCs and gradually normalize during TB treatment. We demonstrated that this process is delayed in TB‐DM, due to prolonged mycobacterial persistence.