Combined Effect of TLR2 Ligands on ROS Production by Mouse Peritoneal Macrophages.

TLR2-mediated ROS production by mouse peritoneal macrophages was studied by luminoldependent chemiluminescence under conditions of cell stimulation with zymosan (TLR2/6 ligand) and peptidoglycan (TLR2/1 ligand). ROS production by macrophages stimulated with zymosan and peptidoglycan simultaneously depended on the ratio of ligand concentrations. Three effects were revealed: additivity of the stimulating effects of the ligands used, competitive ligand binding, and effect of macrophage priming with peptidoglycan during cell stimulation with zymosan. The mechanisms of these effects are discussed.

Pulmonary Tuberculosis: Decreased Activation of T lymphocyte Subsets in vitro.

Protection against M. tuberculosis depends on T cells of the CD4(+) or CD8(+) phenotype. The definition of cellular response and target molecules are important to understand pathological immune mechanisms in tuberculosis. In this report we have analyzed the expression of activation markers (CD25, CD71, HLA DR) on CD4(+), CD8(+) subsets in patients with pulmonary tuberculosis by dual color flow cytometry. We investigated 19 patients with newly diagnosed severe active untreated pulmonary tuberculosis. Previously it was shown, that in the above form of pulmonary tuberculosis amidst CD4(+) and CD8(+) T cells there were a significant decrease in quantity of CD45RA(+) lymphocytes and increase in CD25(+), HLA DR(+) activated cells. To estimate the functional significance of these differences, peripheral blood mononuclear cells were stimulated with polyclonal mitogen phytoheamaglutin in vitro. Since the decreased mitogen response could reflect a difference in the ability of T cell subsets to proliferate, the phenotype of the T cells after stimulation with PHA was determined. Although the patients with PT demonstrated a decreased number of all the T cell subsets (CD25(+), CD71(+), HLA DR(+) after 72 h of PHA-stimulation compared to control, the most pronounced decrease was in CD8(+) cells. Differential analysis of the activation markers in dependence on the flow cytometry gates for PHA-stimulated lymphocytes revealed some defect in the expression of activation markers at the level of small blasts that arrested CD4(+), CD8(+) cells on the early activation stages. Taken together these results suggest that investigated clinical form of pulmonary tuberculosis seems to be directly associated with a defect in reactivity of T lymphocyte subsets at the early activation steps.

[Phenotype of peripheral blood lymphocytes of healthy donors and patients with corneal allotransplantation under conditions of hyperbaric oxygenation]. / Fenotip limfotsitov perifericheskoi krovi zdorovykh donorov i bol'nykh s rogovichnym allotransplantatom v usloviiakh giperbaricheskoi oksigenatsii.

The purpose of this study was to elucidate the possible immunomodulating effect of hyperbaric oxygenation (HBO) on the immune status of patients with various ophthalmopathies and developing the graft-versus-host reaction after perforating keratoplasty. Surface phenotype of the peripheral blood lymphocytes was studied by two-color flow cytofluorometry in donors and patients with the rejection syndrome after transplantation of the cornea before and after a course of oxygen therapy. HBO exerted no immunodepressive effect, as judged from changes in the subpopulation composition (CD3+, CD4+, CD8+, CD16+, and CD56+) and expression of activation markers (CD25 and HLA-DR), in both patients and donors. The most probable explanation is that HBO effect on the immune system is indirect. On the other hand, from a clinical viewpoint the effect of HBO is undoubtedly positive, and hence, HBO exposure may be recommended for clinical application in transplantations of the cornea.

[Increased apoptosis of immunocompetent cells as a possible mechanism in the development of immunodeficiency in patients with acutely progressive tuberculosis]. / Povyshennyi apoptoz immunokompetentnykh kletok kak odin iz vozmozhnykh mekhanizmov v razvitii immunodefitsita u bol'nykh ostroptogressiruiushchim tuberkulezom.

The formation of immunodeficiency whose likely mechanism is apoptosis of some immunocompetent cells was studied in 35 patients with caseous pneumonia. The leading clinical sign of apoptosis in acutely progressive tuberculosis is significant lymphopenia (4-10%). Immunological studies indicated a substantial reduction in the count of T lymphocytes and their regulatory subpopulations of different phenotypes. In vitro mitogenic induction causes a decline of activated CD3+, CD4+, and CD8+ cells on the average by 10-40%, a decrease in the proliferative and synthetic functions, as compared with those in patients with infiltrative tuberculosis of the lung and healthy donors. Cytochemical findings in the same patients show that half the lymphocytes in the blood samples from patients with caseous pneumonia has profound intracellular metabolic disturbances. These cells are unavailable and undergo apoptosis, which determines immunodeficiency in patients with acutely progressive tuberculosis.

[A comparative study of the expression of activation markers on T-lymphocyte subpopulations in different forms of bronchial asthma]. / Sravnitel'noe izuchenie ékspressii markerov aktivatsii na subpopuliatsiiakh T-limfotsitov pri razlichnykh formakh bronkhial'noi astmy.

In this study we investigated a phenotype of intact and PHA-stimulated T-lymphocytes from peripheral blood of patients with allergic and nonallergic asthma. Expression of the activation markers (CD25, CD71, HLA-DR) on subsets of T-lymphocytes (CD4+ and CD8+) was determined using double-colour flow cytometry. It was found that nonallergic patients had increased percentages of CD4+CD25+, CD8+CD25+, CD4+HLA-DR+, CD8+HLA-DR+ cells. Allergic patients had a significant increase of CD4+CD25+ cells only. To examine functional significance of these changes mononuclear cells were cultivated with PHA in vitro. Thus, our findings improve our knowledge about asthma pathogenesis and create the grounds for pathogenetically validated immunocorrection.