Search Results (3)

The immune system is inexperienced before birth and tends to be tolerogenic, rather than immunogenic. After birth, the adaptive immune system develops while facing microbial challenges, but it can become impaired as old age progresses and persistent inflammation can lead to chronic morbidity, disability and frailty. To investigate the potential contributions of lymphocyte subsets to immunity from birth until old age, we enumerated circulating innate and conventional lymphocytes and measured serum cytokine levels in 10 cord blood samples and in peripheral blood from 10 healthy term neonates, 23 healthy school-age children, 25 young adults and 11 older subjects. Flow cytometric analysis revealed that B cell frequencies increase during childhood and gradually decrease into adulthood, whereas natural killer cell frequencies increase throughout life. T cell frequencies remained relatively constant throughout life, as did their expression of CD4 and CD8. However, all four innate T cell populations studied—invariant natural killer T cells, mucosa-associated invariant T cells and the Vδ1 and the Vδ2 subsets of γδ T cells—were extremely rare in cord blood and in peripheral blood of neonates, but they expanded after birth reaching highest levels in adulthood. Analysis of serum cytokine levels revealed that proinflammatory and T helper type 1 (Th1) cytokine levels increase in adulthood, whereas Th2 and Th17 cytokine levels remain relatively constant. These changes in lymphocyte numbers and cytokine levels across the lifetime are likely to affect immunocompetence, leaving newborn and elderly people susceptible to infection, cancer and immune-mediated disease. Full article

Background. We aimed to analyze the contents of the main CD4⁺ T-cell subsets in patients with atherosclerosis (AS) depending on age. Methods. Male patients with coronary and/or carotid AS, who are non-smokers, and who are receiving statins were divided into three age groups (I—<55 y.o. (n = 23), II—55–64 y.o. (n = 42), III—≥65 y.o. (n = 46)). Leukocyte phenotyping was performed by direct immunofluorescence and flow cytometry. For intracellular cytokine detection, blood mononuclear cells were pre-activated with phorbol 12-myristate 13-acetate and ionomycin in the presence of an intracellular vesicle transport blocker monensin. Results. The groups did not differ in traditional CVD risk factors and AS severity. The content of CD4⁺ T-cells was lower in group III and II than in group I. The content of CD4⁺CD25high Treg was lower in group III than in groups I and II. No differences in the quantities of the primed CD39⁺CD45RA⁻ and CD278high Treg, CD4⁺INFγ⁺ Th1, CD4⁺IL17⁺ Th17, and CD4⁺IL17⁺INFγ⁺ Th1/17 were observed. There were negative correlations between the values of CD4⁺ T-cells, CD4⁺CD45RA⁺ T-cells, CD4⁺CD25high Treg, CD4⁺CD25highCD45RA⁺ Treg, and age. Conclusion. In patients with AS, the age-related depletion of naive CD4⁺ T-cells also extends to the regulatory compartment. This phenomenon should be considered when studying the impact of the immune cells on the progression of AS. Full article

CD4+ T cells are sensitive to peripheral changes of cytokine levels and metabolic substrates such as glucose and lactate. This study aimed to analyze whether factors released after exercise alter parameters of human T cell metabolism, specifically glycolysis and oxidative phosphorylation. We used primary human CD4+ T cells activated in the presence of autologous serum, which was collected before (CO) and after a 30-min exercise intervention (EX). In the course of activation, cells and supernatants were analyzed for cell viability and diameter, real-time oxygen consumption by using PreSens Technology, mRNA expression of glycolytic enzymes and complexes of the electron transport chain by real-time PCR, glucose, and lactate levels in supernatants, and in vitro differentiation by flow cytometry. EX did not alter T cell phenotype, viability, or on-blast formation. Similarly, no difference between CO and EX were found for CD4+ T cell activation and cellular oxygen consumption. In contrast, higher levels of glucose were found after 48 h activation in EX conditions. T cells activated in autologous exercise serum expressed lower HK1 mRNA and higher IFN-γ receptor 1. We suggest that the exercise protocol used was not sufficient to destabilize the immune metabolism of T cells. Therefore, more intense and prolonged exercise should be used in future studies. Full article