Expression of CD80 and HLA-DR molecules on blood monocytes in patients with pulmonary tuberculosis

Abstract

We examined expression pattern of CD80 and HLA-DR pro-inflammatory molecules on the monocytes in patients with pulmonary tuberculosis (TB), depending on the clinical form of the disease and susceptibility of the pathogen to anti-tuberculosis drugs. The study involved forty-five patients with newly diagnosed pulmonary TB (25 men and 20 women aged 18 to 55 years, average age — 44.0±12.4 years). The control group included 15 healthy donors with similar socio-demographic characteristics as in TB patients. Venous blood was used as biomaterial for assays. Studies of the monocyte immunophenotype were carried out by flow cytometry of whole blood cells using Cytoflex flow cytometer (Beckman Coulter, USA) with specific monoclonal antibodies (eBioscience, USA). We determined the content of cells expressing surface markers of monocytes, i.e., CD14, CD45, CD80, and HLA-DR. The results of this study were evaluated using SPSS Statistics 17.0 standard software package and Microsoft Excel. In the course of the study, we have suggested a working hypothesis that the monocytes in TB patients, still being in circulation, can express activation markers during their migration to inflammation focus, especially CD80 and HLA-DR molecules. Analysis of the total CD14+ monocyte number showed its decrease in all forms and variants of clinical course of pulmonary tuberculosis compared with the control group. Assessment of pro-inflammatory markers expressed on CD14 positive monocytes, i.e., HLA-DR activation marker and CD80 co-stimulatory molecule, showed that the number of monocytes with HLA-DR expression in all TB patients was higher than in healthy donors. HLA- DR expression on CD14+ monocytes in the group of patients with infiltrative TB proved to be 15% higher than in patients with disseminated TB. The expression of CD80 on CD14+ monocytes in TB patients showed no differences between the groups and varied within the normal range. Hence, an imbalance within monocyte population in patients with pulmonary tuberculosis, regardless of its clinical form and drug sensitivity of the pathogen is developed, due to decrease in total number of CD14+ cells, along with increased relative number of monocytes expressing HLA-DR activation marker (pro-inflammatory phenotype). Meanwhile, expression of the CD80 co-stimulatory molecule on monocytes was within normal values.

Keywords

• monocytes
• pulmonary tuberculosis
• innate immunity
• immune response
• cd80
• hla-dr