T cell Expression of CD153 in Latent Tuberculosis Infection and Type 2 Diabetes Mellitus

Abstract

The increasing prevalence of latent tuberculosis among individuals with type 2 diabetes mellitus has increased the public health importance of TB and non-communicable diseases, yet the immune correlates of protection or susceptibility to TB infection are still poorly understood. Previous studies show that T2DM increases the risk of development of latent TB infection or progression from latent TB to active TB because T2DM down regulates the production of chemokine and cytokines that are important in immune response to Mycobacterium tuberculosis antigen. A recent study suggests that CD153 is one of the biomarkers of protection against TB infection. We hypothesized that individuals with LTBI only have higher expression of CD153 on T cells compared to individuals with both LTBI and T2DM. Understanding the immune correlates of protection would help in better diagnosis, development of new therapeutics, vaccines, and better management of TB and T2DM. Main objective: To determine and compare the frequency of CD153 expressing T cells in individuals with both latent tuberculosis infection and type 2 diabetes mellitus and those with LTBI only. Method: This was a cross-sectional study were we used archived Peripheral Blood Mononuclear Cells. Cells were thawed in a water bath at 37OC and washed by centrifuging in R20 and R10 at room temperature. The PBMCs were stained with optimized antibodies these include; anti-human CD3, anti-human CD4, anti-human CD8, anti-human CD153, anti-human PD1 and zombie aqua. We used flowjo software 10.8.1 for the analysis and GraphPad prism 9.3.1 (471) software for statistical analysis. Results: Notably, CD153+CD8+ T cells showed a significant difference of P value (0.0164). There was no significant difference in frequencies of CD153+CD4+ T cells, PD1+CD4+ T cells and PD1+CD8+ T cells in LTBI only versus LTBI and T2DM. The P values were; 0.1315, 0.4433 and 0.8919 respectively. The correlation test between the frequencies of CD153 and HBA1C percentages showed no correlation (in CD4+ T cells; r = -0.01912, CD8+ T cells; r = 0.01126) and no significant difference in both CD4+ T cells and CD8+ T cells. CD4+ T cells (P value = 0.9506) and CD8+ T cells (P value = 0.9709) in individuals with both LTBI and T2DM. Conclusions: CD153 is not down regulated in a co-infection of LTBI and T2DM. CD153 and PD1 are expressed higher in the co-infection of latent tuberculosis and type 2 diabetes mellitus as compared to latent tuberculosis only. Recommendations: a delve into understanding why CD153 is expressed higher in CD8+ T cells of the co-infected with latent tuberculosis and type 2 diabetes mellitus as compared to latent tuberculosis only.