ABSTRACT
Background: Mycobacterium tuberculosis (Mtb) adapts many strategies to persist and replicate inside human tissue. One such strategy is the manipulation of CD4+ TH cells for subset interconversion to regulatory subsets. The aim of the present study is to get an insight of dynamic changes of CD4+ TH cells to regulatory subsets, CD4+ CD25+ forkhead box P3 (Foxp3)+ T-cells and CD4+ CD25+ Foxp3+ programmed death molecule-1 (Foxp3+) T-cells, in peripheral blood in Mtb-infected individuals and healthy contacts in a high-burden setting from Assam, Northeast India. Materials and Methods: A case–control study was conducted in newly diagnosed active pulmonary tuberculosis (APTBs) patients and 2 sets of controls: (i) individuals infected with latent tuberculosis infection (LTBI) and (ii) healthy close tuberculosis healthy contacts (HCs). The frequencies of different subsets of CD4+ cells with regulatory markers were measured in peripheral blood in 3 groups of study participants. Results and Observations: Frequencies of CD4+ CD25+ Foxp3+ T-cells (1.84 ± 1.40 vs. 4.32 ± 1.82 vs. 11.30 ± 3.66), CD4+ CD25+ Foxp3+ PD1+ T-cells (0.37 ± 1.28 vs. 2.99 ± 3.69 vs. 14.54 ± 5.10) and ligand (PD-L1)-positive CD4+ TH cells (0.80 ± 0.45 vs. 2.28 ± 0.95 vs. 7.13 ± 2.02) were significantly increased from HCs to LTBIs to APTB patients, respectively (P < 0.0001). No significant changes in frequencies of total CD4+ cells were observed between APTBs (29.51 ± 11.93), LTBIs (29.23 ± 8.16) and HCs (28.16 ± 9.73) whereas the mean ratios of CD4+ to CD4+ CD25+ FoxP3+ were significantly decreased from 34.34 ± 47.56 in HCs to 7.96 ± 5.8 in LTBIs to 3.12 ± 2.58 in APTBs (P < 0.0001). Significant decrease in mean ratios of CD4+ CD25+ FoxP3+ to CD4+ CD25+ FoxP3+ PD1+ were also observed from 4.97 ± 1.09 in HCs to 1.44 ± 0.49 in LTBIs to 0.78 ± 0.72 in APTBs. Conclusion: CD4+ TH cells change dynamically to regulatory subsets depending on the status of infection and a shift of response towards excessive regulatory T-cells, and PD-1/PD-L1 production may help in the development of active infection in latently infected individuals. These immunological parameters may be used, as potential biomarkers to see the changing dynamics of Mtb infection.
ABSTRACT
Objectives: In this study, systematic pharmacognostic study and preliminary phytochemical screening of the bark of Cascabela thevetia L. were carried out. Methods: The selected plant part was collected, processed and stored in an airtight container. From the bark different pharmacognostic studies like macroscopic and microscopic evaluation, physicochemical parameters, fluorescence analysis were done. Powdered bark was successively extracted by petroleum ether, chloroform, ethyl acetate, and methanol using a Soxhlet apparatus and finally macerated with the hydro-alcoholic solvent system (30:70). The preliminary phytochemical analysis and thin layer chromatography of the extracts were done to find the nature and number of the different phytoconstituents present. Results: Transverse microscopy reveals the presence of crystal oxalate, cork cell, starch granules, vascular bundle, phloem fiber, parenchyma cells, and collenchyma cells. Powder microscopy also showed the presence of cork cell, fiber and calcium oxalate crystal. Results obtained in different physicochemical analysis like total ash, acid insoluble ash, water soluble ash, alcohol-soluble extractive, water-soluble extractive, and moisture content were 8.67%, 0.83%, 5.33%, 4.53%, 12.27%, and 7.83% respectively. Phytochemical analysis showed the presence of alkaloid, flavonoid, triterpenoid, phytosterol, tannin, saponin, anthraquinone, carbohydrate and fatty acid in the different extracts. TLC (Thin Layer Chromatography) study revealed 4 spots in petroleum ether, chloroform, ethyl acetate, and methanol extracts and 3 spots in the Hydro-alcoholic extract with different solvent systems. Conclusion: The results obtained from the study will provide a reliable basis for identification, purity, and quality of the plant.