Overview of spaceflight immunology studies

Taylor, Gerald R.

doi:10.1002/jlb.54.3.179

Cited by 86 publications

(35 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The effects of spaceflight on the immune system are not caused simply by physical and psychological stress but may also be directly affected by microgravity (Martinelli et al, 2009). Previous studies have shown that microgravity and SMG can affect both the proliferation and viability of lymphocytes, which suggests that their effects occur at the cellular level (Meehan et al, 1992;Taylor, 1993;Cooper and Pellis, 1998;Sastry et al, 2001;Martinelli et al, 2009).…”

Section: Discussionmentioning

confidence: 99%

Effects of Simulated Microgravity on Primary Human NK Cells

Mei²,

Huyan³

et al. 2013

Astrobiology

View full text Add to dashboard Cite

The deleterious effects of microgravity on lymphocytes have been demonstrated in previous studies. However, research on the effects of microgravity on human natural killer (NK) cells remains exceedingly limited. In this study, we demonstrated that NK cell cytotoxicity was significantly decreased under simulated microgravity (SMG) conditions ( p < 0.05). Several processes, including apoptosis, receptor expression, and cytokine secretion, were investigated in human NK cells under SMG. We observed decreased cytotoxicity, concurrent with increased apoptosis and necrosis, in NK cells after exposure to SMG ( p < 0.05). Additionally, interferon (IFN)-c and perforin expression decreased significantly, and the expression of granzyme-B was only slightly reduced. Meanwhile, SMG selectively inhibited the expression of certain surface receptors on NK cells. Specifically, the expression of NKG2A and NKG2D were significantly downregulated under SMG, but the expression of NKp30 and NKp44 was not affected. We also found that interleukin (IL)-15 alone or in combination with IL-12 could counteract the inhibition of NK cell cytotoxicity under SMG. Our findings indicate that human NK cells were sensitive to SMG, as reflected by their decreased cytotoxicity. Factors such as increased early apoptosis and late apoptosis/necrosis and the decreased expression of INF-c, cytolytic proteins, and cell surface receptors may be responsible for the loss of cytotoxicity in human NK cells under SMG. A combination of IL-12 and IL-15 may be useful as a therapeutic strategy for overcoming the effects of microgravity on human NK cells during long space missions.

show abstract

Section: Discussionmentioning

confidence: 99%

Effects of Simulated Microgravity on Primary Human NK Cells

Mei²,

Huyan³

et al. 2013

Astrobiology

View full text Add to dashboard Cite

show abstract

“…Additionally, confinement of the crew during flight can and has resulted in the transfer of microorganisms between crew members (13,26,27). All of these factors are known to affect many physiological parameters of the astronauts, including the immune system (12,17,20,31,32,41). Their effects include decreased functions of cells of the innate immune system, including neutrophils (14, 36), monocytes (15), and NK cells (17,21).…”

mentioning

confidence: 99%

Effect of Spaceflight on Ability of Monocytes To Respond to Endotoxins of Gram-Negative Bacteria

Kaur

Simons

Kapadia

et al. 2008

Clin Vaccine Immunol

View full text Add to dashboard Cite

Astronauts live and work in relatively crowded, confined environments on the Space Shuttle and the International Space Station. They experience a unique set of stressors that contribute to a diminishment of many immune responses. This study investigated the ability of the shuttle crew members' monocytes to respond to gram-negative endotoxin that they could encounter during infections. Blood specimens were collected from 20 crew members and 15 control subjects 10 days before launch, 3 to 4 h after landing, and 15 days after landing and from crew members during their annual medical examination at 6 to 12 months after landing. When challenged with gram-negative endotoxin, the crew member's monocytes collected at all three time points produced lower levels of interleukin-6 (IL-6) and IL-1␤ and higher levels of IL-1ra and IL-8 compared to those of control subjects. Cytokines were assessed by measuring the number of cells positive for intracellular cytokines. These values returned to normal 6 to 12 months after landing, except for IL-1ra, which was still higher (five-to sixfold) than in controls. This phenomenon was accompanied by an increased expression of Toll-like receptor 4 and decreased expression of CD14 on the crew members' monocytes at all time points. There were also increased levels of the lipopolysaccharide binding protein in the plasma of the crew members 3 to 4 h and 15 days after landing. This study shows that spaceflight-associated factors (in-flight and preflight) modulate the response of monocytes to gram-negative endotoxins.During spaceflight, astronauts are affected by many unusual factors, such as microgravity, radiation, physical and mental stresses, and isolation. Not only is spaceflight associated with in-flight factors influencing the astronauts, but even before launch, in preparation for the mission, the astronauts experience changes in circadian rhythms, rigorous training, and stresses of anticipation factors. Additionally, confinement of the crew during flight can and has resulted in the transfer of microorganisms between crew members (13,26,27). All of these factors are known to affect many physiological parameters of the astronauts, including the immune system (12,17,20,31,32,41). Their effects include decreased functions of cells of the innate immune system, including neutrophils (14, 36), monocytes (15), and NK cells (17,21). The innate immune system initiates the host defense against invading microbes by specific recognition mechanisms. The family of Toll-like receptors (TLRs) on monocytes have been shown to be involved in innate immune recognition in response to microbial antigens (1, 6, 38), such as lipopolysaccharide (LPS), or endotoxin, a major virulence factor of gram-negative bacteria (29). Tapping et al. (39) have shown that TLR4 is the predominant signaling receptor for LPS in human blood. In blood, LPS binds to LPS binding protein (LBP), which facilitates the transfer of LPS to CD14 molecules in the CD14-TLR4-MD2 complex on the cell membrane of monocytes (11). CD14 plays a ke...

show abstract

“…A number of examples exist of test panels that are in use or have been recommended by government agencies and private-sector scientists involved in immunologic field assessment (Beisel and Talbot, 1985;Taylor, 1993 . The outcomes of this workshop included recommendations for a panel of tests for assessment of immune deficiency as well as factors that must be considered in the design of field studies.…”

Section: Assessment Techniquesmentioning

confidence: 99%

“…However, assays of whole-blood cytokine production (De Rijk et al, 1996 may provide a more sensitive method than was available previously to measure immune changes associated with exercise and stress. The choice of techniques will depend on the investigator's resources and the availability and accessibility of tissue, blood, or biological fluid to be assayed.A number of examples exist of test panels that are in use or have been recommended by government agencies and private-sector scientists involved in immunologic field assessment (Beisel and Talbot, 1985;Taylor, 1993 . The outcomes of this workshop included recommendations for a panel of tests for assessment of immune deficiency as well as factors that must be considered in the design of field studies.…”

mentioning

confidence: 99%

Military Strategies for Sustainment of Nutrition and Immune Function in the Field

Poos¹,

Costello²,

Carlson-Newberry³

1999

View full text Add to dashboard Cite

The serpent has been a symbol of long life, healing, and knowledge among almost all cultures and religions since the beginning of recorded history. The image adopted as a logotype by the Institute of Medicine is based on a relief carving from ancient Greece, now held by the Staatliche Museen in Berlin.Cover: Resting monocyte/macrophage being activated to produce proinflammatory cytokines which form complexes with receptor binding proteins. Adapted from COMMITTEE ON MILITARY NUTRITION RESEARCHROBERT O. NESHEIM (Chair, through June 30, 1998) (FNB), Institute of Medicine, National Academy of Sciences. Other workshops or symposia have included such topics as food components to enhance performance; nutritional needs in hot, cold, and high-altitude environments; body composition and physical performance; nutrition and physical performance; cognitive testing methodology; and fluid replacement and heat stress. These workshops form part of the response that the CMNR provides to the Commander, U. HISTORY OF THE COMMITTEEThe CMNR was established in October 1982 following a request by the Assistant Surgeon General of the Army that the Board on Military Supplies of the National Academy of Sciences set up a special committee. The purpose of this committee was to advise the U.S. Department of Defense on the need for and conduct of nutrition research and related issues. The CMNR was transferred to the FNB in 1983. The CMNR's current tasks are• to identify nutritional factors that may critically influence the physical and mental performance of military personnel under all environmental extremes,• to identify deficiencies in the existing database, • to recommend research that would remedy these deficiencies as well as approaches for studying the relationship of diet to physical and mental performance, and• to review and advise on standards for military feeding systems.Within this context, the CMNR was asked to focus on nutrient requirements for performance during operational missions rather than requirements for military personnel in garrison (the latter were judged to be not significantly different from those of the civilian population).Although the membership of the committee has changed periodically, the disciplines represented consistently have included human nutrition, nutritional biochemistry, performance physiology, food science, and psychology. For issues that require broader expertise than exists within the committee, the CMNR has convened workshops or utilized consultants. The workshops provide additional state-of-the-art scientific information and informed opinion for the consideration of the committee. COMMITTEE TASKS AND PROCEDURESThe request for this review of nutrition and immune function and its application to military operations originated with Army scientists from USARIEM and USAMRMC. In December 1995, a committee subgroup of the CMNR participated in a series of conference calls with USARIEM, USAMRMC, and other CMNR members to identify the key areas that should be reviewed and to solicit suggestions for names...

show abstract

Overview of spaceflight immunology studies

Cited by 86 publications

References 0 publications

Effects of Simulated Microgravity on Primary Human NK Cells

Effects of Simulated Microgravity on Primary Human NK Cells

Effect of Spaceflight on Ability of Monocytes To Respond to Endotoxins of Gram-Negative Bacteria

Military Strategies for Sustainment of Nutrition and Immune Function in the Field

Contact Info

Product

Resources

About