Time-of-day effects on response of natural killer cells to acute stress in men and women.

Delahanty, Douglas L.; Wang, Taiping; Maravich, Craig; Forlenza, Michael J.; Baum, Andrew

doi:10.1037//0278-6133.19.1.39

Cited by 7 publications

(1 citation statement)

References 23 publications

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“…Circadian rhythms influence immune cell trafficking between blood, tissue, and lymphatic vessels [ 12 ]. Natural killer cell activity increases during the morning and tapers off as the day continues [ 13 ]. B-cell and T-cell functions also vary with circadian rhythms wherein the time of day can significantly impact the effectiveness of immune responses [ 14 , 15 ].…”

Section: Introductionmentioning

confidence: 99%

Rapid increase in immune surveillance and expression of NKT and γδT cell activation markers after consuming a nutraceutical supplement containing Aloe vera gel, extracts of Poria cocos and rosemary. A randomized placebo-controlled cross-over trial

Yu,

McGarry,

Cruickshank

et al. 2023

PLoS ONE

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Goal To evaluate the acute impact of a nutraceutical blend on immune surveillance. Study design A randomized, double-blind, placebo-controlled, cross-over trial was conducted in 11 healthy subjects. Blood samples were taken immediately before and at 1, 2, and 3 hours after consuming placebo or 500 mg of UP360, which is a blend of botanicals from Aloe vera, Poria cocos, and rosemary (APR extract). Immunophenotyping and flow cytometry quantified numbers of monocytes, NK cells, NKT cells, CD8+ cytotoxic T cells, γδT cells, and total T cells, and expression of CD25 and CD69 activation markers. Plasma was tested for cytokines, chemokines, growth factors, and enzymatic activity of superoxide dismutase and catalase. Results Compared to the placebo, consumption of APR extract triggered rapid increases in chemokine levels starting at 1 hour, including IP-10 (P<0.05) and MCP-1 (P<0.1), which peaked at 2 hours (P<0.01) and 3 hours (P<0.05), respectively. The stem cell-mobilizing growth factor G-CSF increased at 2 hours (P<0.05). Increased immune surveillance involved a transient effect for monocytes at 1 hour, followed by NKT cells, CD8+ cytotoxic T cells, and γδT cells at 2–3 hours. Increased immune cell alertness was seen at 1 hour by increased CD25 expression on monocytes (P<0.01), NKT cells (P<0.01), and T cells (P<0.05). NKT cells showed upregulation of CD69 at 2 hours (P<0.01). Increased enzymatic activity was seen at 2 hours for the antioxidant enzymes superoxide dismutase (P<0.05) and catalase (P<0.01). Conclusion Consumption of APR extract triggered acute changes to chemokine levels. In addition, immune alertness was increased via the expression of activation markers on multiple types of innate immune cells, followed by increased immune surveillance and antioxidant protection. This suggests a beneficial enhancement of natural immune surveillance, likely via a combination of gut-mediated cytokine release and vagus nerve communication, in combination with cellular protection from oxidative stress.

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Section: Introductionmentioning

confidence: 99%

Rapid increase in immune surveillance and expression of NKT and γδT cell activation markers after consuming a nutraceutical supplement containing Aloe vera gel, extracts of Poria cocos and rosemary. A randomized placebo-controlled cross-over trial

Yu,

McGarry,

Cruickshank

et al. 2023

PLoS ONE

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Psychological Stress and the Human Immune System: A Meta-Analytic Study of 30 Years of Inquiry.

Segerstrom

Miller

2004

Psychological Bulletin

2,658

1,845

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The present report meta-analyzes more than 300 empirical articles describing a relationship between psychological stress and parameters of the immune system in human participants. Acute stressors (lasting minutes) were associated with potentially adaptive upregulation of some parameters of natural immunity and downregulation of some functions of specific immunity. Brief naturalistic stressors (such as exams) tended to suppress cellular immunity while preserving humoral immunity. Chronic stressors were associated with suppression of both cellular and humoral measures. Effects of event sequences varied according to the kind of event (trauma vs. loss). Subjective reports of stress generally did not associate with immune change. In some cases, physical vulnerability as a function of age or disease also increased vulnerability to immune change during stressors.Since the dawn of time, organisms have been subject to evolutionary pressure from the environment. The ability to respond to environmental threats or stressors such as predation or natural disaster enhanced survival and therefore reproductive capacity, and physiological responses that supported such responses could be selected for. In mammals, these responses include changes that increase the delivery of oxygen and glucose to the heart and the large skeletal muscles. The result is physiological support for adaptive behaviors such as "fight or flight." Immune responses to stressful situations may be part of these adaptive responses because, in addition to the risk inherent in the situation (e.g., a predator), fighting and fleeing carries the risk of injury and subsequent entry of infectious agents into the bloodstream or skin. Any wound in the skin is likely to contain pathogens that could multiply and cause infection (Williams & Leaper, 1998). Stress-induced changes in the immune system that could accelerate wound repair and help prevent infections from taking hold would therefore be adaptive and selected along with other physiological changes that increased evolutionary fitness.Modern humans rarely encounter many of the stimuli that commonly evoked fight-or-flight responses for their ancestors, such as predation or inclement weather without protection. However, human physiological response continues to reflect the demands of earlier environments. Threats that do not require a physical response (e.g., academic exams) may therefore have physical consequences, including changes in the immune system. Indeed, over the past 30 years, more than 300 studies have been done on stress and immunity in humans, and together they have shown that psychological challenges are capable of modifying various features of the immune response. In this article we attempt to consolidate empirical knowledge about psychological stress and the human immune system through meta-analysis. Both the construct of stress and the human immune system are complex, and both could consume bookCorrespondence concerning this article should be addressed to Suzanne C. Segerstrom, Department of Ps...

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Psychoneuroimmunology and trauma.

Dougall

Baum

2004

Trauma and Health: Physical Health Consequences of Exposure to Extreme Stress.

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In this chapter we review research suggesting that stress-related changes in immune system function mediate many associations between traumatic stressors and infectious illness, cancer, HIV disease progression, and other aspects of physical health. It is widely accepted that reliable changes in immune activity are seen in the wake of exposure to stressors, but the extent to which observed stress-related changes affect susceptibility to disease or infection is not yet resolved. Brief discussion of relationships between stressors and immune system regulation and consideration of potential health effects of these relationships will include direct effects of stress on the immune system and indirect effects mediated through stress-related changes in other physiological, psychological, and behavioral pathways that also affect immunity (e.g., neuroendocrines, psychosocial variables, and health behaviors). Stress-related immune components of illness or related events are considered as well. We identify major gaps in the literature and examine future directions for research and practice.

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Time-of-day effects on response of natural killer cells to acute stress in men and women.

Cited by 7 publications

References 23 publications

Rapid increase in immune surveillance and expression of NKT and γδT cell activation markers after consuming a nutraceutical supplement containing Aloe vera gel, extracts of Poria cocos and rosemary. A randomized placebo-controlled cross-over trial

Rapid increase in immune surveillance and expression of NKT and γδT cell activation markers after consuming a nutraceutical supplement containing Aloe vera gel, extracts of Poria cocos and rosemary. A randomized placebo-controlled cross-over trial

Psychological Stress and the Human Immune System: A Meta-Analytic Study of 30 Years of Inquiry.

Psychoneuroimmunology and trauma.

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