Immunophenotyping Analysis of Peripheral T and B Lymphocytes in Patients with Chronic Pulmonary Tuberculosis

Abstract

Cellular immune response plays a critical role in the containment of persistent Mycobacterium tuberculosis infection. However, the immunological mechanisms that lead to the control are not complete identified. The goal of this study was to evaluate CD3+ (T) and CD19+ (B) lymphocytes profiles, and, CD4+ (helper T lymphocytes), CD8+ (cytotoxic T lymphocytes) and CD3+CD4+CD25+ (regulatory T lymphocytes or Tregs) subsets in patients with chronic pulmonary tuberculosis (CTB). Peripheral blood mononuclear cells (PBMC) from patients and healthy donors were isolated by Histopaque-1077 gradient centrifugation. PBMC were stained with a combination of mAbs as follow: to analyze T and B cells, double labeling was performed using anti-CD3PerCP and anti-CD19FITC. To evaluate T cells subpopulations, a triple labeling were made using: anti-CD4FITC/anti-CD8PE/anti-CD3PerCP or anti-CD3PerCP/anti-CD4FITC/anti-CD25PE. For isotype controls, cells were stained with Simultest 2aFITC/ 1PE. Cells were acquired and analyzed with a fluorescence activated cell sorter FACScalibur using the CellQuest software. Differences between patients and healthy were analyzed by a non-parametric method of U-Mann Whitney using SPSS version 10.00 for windows, and significance differences were considered with a P < 0.05. Percentages of CD3+ cells were similar in CTB and healthy donors (P = 0.6). In contrast, percentage of B lymphocytes was significant lower in CTB than in healthy subjects (P = 0.03). A significant predominance (P = 0.0006) of CD4+ T cells over CD8+ T cells was observed on both groups. No significant changes on CD4+ (P = 0.2) or CD8+ (P = 0.5) T cells between CTB patients and healthy controls were observed. However, percentage of Tregs lymphocytes was significant higher in CTB than in healthy donors (P = 0.009). According with these results we suggest that low percentage of CD19+ cells and high percentage of Tregs lymphocytes (CD3+CD4+CD25+) can be a mark of patients with chronic TB.