Acute stress reduces intraparenchymal lung natural killer cells via beta-adrenergic stimulation

Abstract

SummaryThere are lines of evidence that natural killer (NK) cells are sensitive to physical and psychological stress. Alterations in the immune system including NK cells are known to differ among tissues and organs. The effect of stress on the lung immune system, however, has not been well documented in spite of the fact that the lungs always confront viral or bacterial attacks as well as tumour cell metastasis. In this study, we intended to investigate the effect of restraint stress on lung lymphocytes including NK cells. C57BL/6 mice were exposed to 2 h restraint stress. The concentration of plasma epinephrine significantly rose immediately after the release from restraint as compared to home-cage control mice. Flow cytometric analysis revealed that the numbers of most lymphocyte subsets including NK cells were decreased in the lungs and blood but not in the spleen, immediately after restraint stress. Immunohistochemical examination revealed that the number of NK cells was decreased in the intraparenchymal region of the lungs, while the number of alveolar macrophages did not change. The decrease in the number of NK cells in the lungs and blood was reversed by the administration of propranolol, a nonselective beta adrenergic antagonist. Taken together, our findings suggest that acute stress reduces the number of intraparenchymal lung NK cells via activation of beta adrenergic receptors.

Acute stress augments innate immunity in the liver and increases hyaluronan levels in the tissues and blood of mice

“…We used a conventional method to administer restraint stress to mice (4,6,8,19,38). That is, mice were exposed to acute stress for 6 h using a 50-mL centrifuge tube having a sufficient number of holes for ventilation to prevent an acute rise in body temperature.…”

“…Not only physical stress (21,22,28,30,32) but also psychological and psychosocial stress (3,4,8,14,19,38) increases the concentrations of catecholamines (i.e., adrenalin, noradrenalin, and dopamine) in the peripheral blood, resulting in a change in the number of lymphocytes (4,6,8,12,19,20,22,23). As for the clinical importance of stress, acute stress activates inflammation and improves wound healing, vaccination effectiveness and resistance to infection (7,9,10,38), while chronic stress is immunosuppressive (25) and impairs wound healing (11,29).…”

Acute Stress induces the modification of the lymphocyte proteins of mouse liver

“…If we could identify the proteins appeared in the stressed lymphocytes and could examine the genes of these proteins, we may get some insights into the relationship between the changes of proteins, the difference of the some subsets, and the decrease of the number occurred in the stressed liver lymphocytes, leading us to deeper understanding of the stress. There have been many reports that indicated the decrease of the number of lymphocytes and the changes of some subsets of lymphocyte in various organs under the influence of some kinds of stresses (4,12,13,20,23). According to the results shown in the reports cited above, the stress has induced the decrease of the number of the lymphocytes and the changes of the parcentage of some subsets of lymphocyte in peripheral blood, some portions of lung, and liver.…”

“…We used conventional method to administer restraint stress to mice (3,4,12,13,24). above using the suspension medium without NCS (see "DISCUSSION").…”

“…Not only physical stress (15,16,20,22,23) but also psychological and psychosocial stress (2,3,6,(11)(12)(13)24) increase the concentrations of adrenalin, noradrenalin, and dopamine in peripheral blood plasma, resulting in the change of lymphocyte numbers in peripheral blood (3,4,6,10,13,14,16,17). As for clinical importance, acute stress activates immune system and improves wound healing, vaccination, or resistance to infection (5,7,8,24), while chronic stress is immunosuppressive (19) and impairs wound healing (9,21).…”