Effects of 60-day bed rest with and without exercise on -ellular and humoral immunological parameters

Exercise at regular intervals is assumed to have a positive effect on immune functions. Conversely, after spaceflight and under simulated weightlessness （e.g., bed rest）, immune functions can be suppressed. We aimed to assess the effects of simulated weightlessness （Second Berlin BedRest Study; BBR2-2） on immunological parameters and to investigate the effect of exercise （resistive exercise with and without vibration） on these changes. Twenty-four physically and mentally healthy male volunteers （20-45 years） performed resistive vibration exercise （n= 7）, resistance exercise without vibration （n=8） or no exercise （n=9） within 60 days of bed rest. Blood samples were taken 2 days before bed rest, on days 19 and 60 of bed rest. Composition of immune cells was analyzed by flow cytometry. Cytokines and neuroendocrine parameters were analyzed by Luminex technology and ELISA/RIA in plasma. General changes over time were identified by paired t-test, and exercise-dependent effects by pairwise repeated measurements （analysis of variance （ANOVA））. With all subjects pooled, the number of granulocytes, natural killer T cells, hematopoietic stem cells and CD45RA and CD25 co-expressing T cells increased and the number of monocytes decreased significantly during the study; the concentration of eotaxin decreased significantly. Different impacts of exercise were seen for lymphocytes, B cells, especially the IgD＋ subpopulation of B cells and the concentrations of IP-IO, RANTES and DHEA-S. We conclude that prolonged bed rest significantly impacts immune cell populations and cytokine concentrations. Exercise was able to specifically influence different immunological parameters. In summary, our data fit the hypothesis of immunoprotection by exercise and may point toward even superior effects by resistive vibration exercise.

Prognostic Significance of Tumor-infiltrating CD8^＋ or CD3^＋ T Lymphocytes and Interleukin-2 Expression in Radically Resected Non-small Cell Lung Cancer

Background：Altered immunoresponse is associated with tumorigenesis and cancer progression.This study assessed the levels of tumor-infiltrating CD3^＋ or CD8^＋ T lymphocytes and interleukin-2 （IL-2） protein in radically resected non-small cell lung cancer （NSCLC） tissues to predict overall survival （OS） of the patients.Methods：Paraffin-embedded tissue specimens from 129 NSCLC patients were retrospectively collected for immunostaining of CD8^＋,CD3^＋,and IL-2 expression.Clinicopathological and survival data were collected and analyzed using the Chi-squared test,Kaplan-Meier curves,and the log-rank test or the Cox regression model.Results：The data showed a significant inverse association between CD8^＋ T lymphocyte levels and IL-2 expression （r =-0.927; P =0.000） and between the levels of CD8^＋ and CD3^＋ T lymphocytes （r =-0.722; P =0.000）,but a positive association between CD3^＋ T lymphocyte levels and IL-2 expression （r =0.781; P =0.000） in NSCLC tissues.Furthermore,the levels of CD3^＋ and CD8^＋ T lymphocytes and IL-2 expression were associated with tumor stage （P =0.023,0.006,and 0.031,respectively） and the level of CD8^＋ T lymphocytes was associated with the patient gender （P =0.024）.In addition,the levels of CD8^＋ T lymphocytes were associated with an unfavorable 5-year OS,whereas patients with high levels of CD3^＋ T lymphocytes in tumor lesions and IL-2-expressing tumors had significantly better 5-year OS rates than patients with low levels.Conclusions：The levels of CD8^＋ T cells in tumor lesions and IL-2 expression were both independent predictors of OS for these NSCLC patients.Thus,the detection of tumor-infiltrating CD3^＋ or CD8^＋ T lymphocytes and IL-2 expression could be useful to predict the prognosis of radically resected NSCLC patients.