Heather Quiriarte

Plasma Cytokine Concentrations Indicate That In Vivo Hormonal Regulation of Immunity Is Altered During Long-Duration Spaceflight

Aspects of immune system dysregulation associated with long-duration spaceflight have yet to be fully characterized and may represent a clinical risk to crewmembers during deep space missions. Plasma cytokine concentration may serve as an indicator of in vivo physiological changes or immune system mobilization. The plasma concentrations of 22 cytokines were monitored in 28 astronauts during long-duration spaceflight onboard the International Space Station. Blood samples were collected 3 times before flight, 3-5 times during flight (depending on mission duration), at landing, and 30 days after landing. Analysis was performed by bead array immunoassay. With few exceptions, minimal detectable mean plasma concentrations were observed at baseline (launch minus 180) for innate inflammatory cytokines or adaptive regulatory cytokines; however, interleukin (IL)-1ra and several chemokines and growth factors were constitutively present. An increase in the plasma concentration, tumor necrosis factor-α (TNFα), IL-8, IL-1ra, thrombopoietin (Tpo), vascular endothelial growth factor (VEGF), C-C motif chemokine ligand 2 (CCL2), chemokine ligand 4/macrophage inhibitory protein 1b (CCL4), and C-X-C motif chemokine 5/epithelial neutrophil-activating protein 78 (CXCL5) was observed associated with spaceflight. No significant alterations were observed during or following spaceflight for the inflammatory or adaptive/T-regulatory cytokines: IL-1α, IL-1β, IL-2, interferon-gamma (IFN-γ), IL-17, IL-4, IL-5, IL-10, G-CSF, GM-CSF, FGF basic, CCL3, or CCL5. This pattern of cytokine dysregulation suggests multiple physiological adaptations persist during flight, including inflammation, leukocyte recruitment, angiogenesis, and thrombocyte regulation.

Monocyte phenotype and cytokine production profiles are dysregulated by short-duration spaceflight.

INTRODUCTION Immune system dysregulation has been demonstrated to occur during and immediately following spaceflight. As the initial bias and magnitude for an immune response is heavily influenced by monocyte/macrophage secreted cytokines, this study investigated monocyte phenotype and cytokine production patterns following short-duration spaceflight. METHODS Secreted cytokine profiles were examined by cytometric bead array analysis of culture supernatants following whole blood culture activation with LPS or PMA+ionomycin. Nine short-duration Space Shuttle crewmembers participated in this study. RESULTS Peripheral monocyte percentages were unaltered postflight. Constitutive monocyte expression of both CD62L and HLA-DR was reduced following spaceflight in a mission-specific fashion. Loss of either molecule indicates a functional disability of monocytes, either by inhibition of adhesion and tissue migration (CD62L) or by impaired antigen presentation (HLA-DR). Following LPS stimulation of monocytes, postflight expression of IL-6, TNFalpha, and IL-10 were significantly reduced (by 43%, 44%, and 41%, respectively) and expression of IL-1b was elevated (65%). IL-8 production was either elevated or reduced in a mission-specific fashion. Following PMA+ionomycin stimulation of all leukocyte populations, only expression of IL-6 was significantly reduced postflight. DISCUSSION These data indicate that changes in monocyte constitutive phenotype and inflammatory cytokine production occur following short-duration spaceflight, which may impact overall crewmember immunocompetence. Also, monocyte/macrophage function may be highly sensitive to mission specific parameters.

Alterations in adaptive immunity persist during long-duration spaceflight

Background:It is currently unknown whether immune system alterations persist during long-duration spaceflight. In this study various adaptive immune parameters were assessed in astronauts at three intervals during 6-month spaceflight on board the International Space Station (ISS).AIMS:To assess phenotypic and functional immune system alterations in astronauts participating in 6-month orbital spaceflight.Methods:Blood was collected before, during, and after flight from 23 astronauts participating in 6-month ISS expeditions. In-flight samples were returned to Earth within 48 h of collection for immediate analysis. Assays included peripheral leukocyte distribution, T-cell function, virus-specific immunity, and mitogen-stimulated cytokine production profiles.Results:Redistribution of leukocyte subsets occurred during flight, including an elevated white blood cell (WBC) count and alterations in CD8+ T-cell maturation. A reduction in general T-cell function (both CD4+ and CD8+) persisted for the duration of the 6-month spaceflights, with differential responses between mitogens suggesting an activation threshold shift. The percentage of CD4+ T cells capable of producing IL-2 was depressed after landing. Significant reductions in mitogen-stimulated production of IFNγ, IL-10, IL-5, TNFα, and IL-6 persisted during spaceflight. Following lipopolysaccharide (LPS) stimulation, production of IL-10 was reduced, whereas IL-8 production was increased during flight.Conclusions:The data indicated that immune alterations persist during long-duration spaceflight. This phenomenon, in the absence of appropriate countermeasures, has the potential to increase specific clinical risks for crewmembers during exploration-class deep space missions.

A case of persistent skin rash and rhinitis with immune system dysregulation onboard the International Space Station

There is now ample evidence to confirm that dysregulation of various immune system parameters, including leukocyte distribution, functional capacity of various cellular populations, and cytokine production profiles, is associated with spaceflight. This phenomenon was recently found to persist for the duration of a 6-month deployment to the International Space Station (ISS). In astronauts, the reactivation of latent herpesviruses has been correlated with immune system alterations. There is a common perception that astronauts do not experience illness during flight. This may be due to the (appropriately) restricted nature of an astronaut’s confidential medical information, or related to successful preflight quarantine and living in a quasi-isolation chamber. Nevertheless, astronauts do indeed experience varying degrees of illness. For this case report, we track symptomology, medication use, and research immunology findings for an ISS astronaut during a typical 6-month flight onboard ISS. This particular crewmember experienced a chronic rash, which occurred early and never fully resolved during the course of the mission. We overlay observed symptoms with major mission events, to highlight a potential relationship between clinical outcomes and mission stress. Parallel data from a biomedical research investigation are presented in this article’s Online Repository at www.jaci-inpractice.org. This ISS mission consisted of 191 flight days from launch to landing. Occurring during this ISS deployment were the dockings of 3 Space Shuttle missions, 2 Soyuz vehicles, 2 Russian “Progress” cargo vehicles, and 1 European Space Agency “ATV” cargo vehicle. The crewmember participated in 5 EVAs (extravehicular activities—spacewalks). There were also 12 additional EVAs or spacewalks that occurred during Shuttle docked operations. These additional EVAs were performed by Shuttle crewmembers, but required support and guidance by ISS crewmembers. The crewmember also supported other significant on-orbit operations such as relocation of modules and hardware installation. All major mission events, including vehicle docking and/or undocking, and EVAs are represented in Figure 1. Crewmember on-orbit blood, saliva, and urine sample collections are also indicated, as are crewmember circadian rhythm shifts. Generally, these rhythm shifts are purposeful and preplanned by ground control to support mission operations. Other relevant medical data such as symptomatic incidents or periods of relevant medication usage are also represented. Using this information, clinical findings and research data may be interpreted in the context of the mission schedule and on-orbit events. The case study crewmember experienced no unusual symptoms, other than those associated with normal adaptation to microgravity, before flight day 17. The crewmember then developed a rash, possibly dermatitis, on flight day 17. This corresponded to the first period of notable stress in the mission, coinciding with a Shuttle docking and an extremely high workload (Figure 1). The rash presented red, bumpy, and very itchy areas on the back and neck (Figure 2). Coinciding with the rash development was the appearance of eye and upper respiratory rhinitis symptoms, primarily sneezing and itchy, watery eyes. It is noteworthy that the crewmember does not experience terrestrial allergies of any kind and had never previously required any antihistamine medication. The occurrence of symptoms and rash severity over the general mission timeline is presented in Figure 1. Rash severity was tracked on a relative 1-10 scale between the crewmember and flight surgeon, with guidance having been provided to the crewmember to grade based on discomfort and operational impact. The crewmember treated the rash with hydrocortisone cream as needed at the crewmembers’ discretion. The use of this medication was not recorded daily, but per the crewmember, it was used heavily for the duration of the mission. The crewmember was also prescribed fluconazole on mission day 22, on the possibility that the rash could have fungal component. The antifungal had no beneficial effect on the rash. Near to the Shuttle undocking on flight day 27, there was general improvement in the rash severity, and the rhinitis symptoms were treated with, and responded to, an oral antihistamine. A worsening of rash symptoms occurred around mission day 33, immediately after an EVA, and coinciding with a period of notable on-orbit operations. Terbinafine cream was prescribed for use as needed on flight day 34. The severity of the rash generally diminished to 1-2þ by mission day 48, after 2 more EVAs. On flight day 69, the most challenging EVA (per the crewmember description) occurred. On mission day 71, a crewmate received some distressing personal news regarding a death in the family. This event was a psychological stressor for the entire crew. On mission day 73, the rash flared to its worst point in the 6-month mission, described by the crewmember as 10þ. We retrospectively anticipate, based on rash locations, appearance, and discomfort and/or itch, that this level of severity would correspond to approximately 30-37 on the Scoring Atopic Dermatitis scale. At this point, the hydrocortisone cream was exhausted. Triamcinolone acetonide cream was used and was found to be ineffective. A methylprednisolone steroid dosepack was prescribed, and the rash improved during the initial period of the 6-day treatment, with return of symptoms on the fifth day of the tapering. A 30 mg prednisone dose was initiated with a much

A Miniaturized Analyzer Capable of White-Blood- Cell and Differential Analyses During Spaceflight

Spaceflight has adverse effects on the human body that pose health risks to astronauts spending extended time in space missions. For clinical monitoring of astronauts and for in-flight biomedical research, laboratory instruments must be available in the spaceflight environment. Currently, no instrument has been shown to be capable of generating a white blood cell (WBC) count and differential during spaceflight to our knowledge, although this is a medical requirement of the National Aeronautics and Space Administration (NASA). We evaluated a compact hematology analyzer for compatibility with a zero-gravity environment. We performed analyses in reduced-gravity during parabolic flight. Herein, we describe our engineering evaluation and report the reduced-gravity validation data we collected. The hematology analyzer we tested met the basic requirements for use in spaceflight and should be capable of accurately measuring WBC parameters aboard the International Space Station. * ISS : International Space Station; WBC : white blood cell; NASA : National Aeronautics and Space Administration; CCD : charge-coupled device; EDTA : ethylenediaminetetraacetic acid; CBC : complete blood cell; CLIA : Clinical Laboratory Improvement Amendments; IR&D : Internal Research and Development

Evaluation of techniques for performing cellular isolation and preservation during microgravity conditions

Genomic and epigenomic studies require the precise transfer of microliter volumes among different types of tubes in order to purify DNA, RNA, or protein from biological samples and subsequently perform analyses of DNA methylation, RNA expression, and chromatin modifications on a genome-wide scale. Epigenomic and transcriptional analyses of human blood cells, for example, require separation of purified cell types to avoid confounding contributions of altered cellular proportions, and long-term preservation of these cells requires their isolation and transfer into appropriate freezing media. There are currently no protocols for these cellular isolation procedures on the International Space Station (ISS). Currently human blood samples are either frozen as mixed cell populations (within the CPT collection tubes) with poor yield of viable cells required for cell-type isolations, or returned under ambient conditions, which requires timing with Soyuz missions. Here we evaluate the feasibility of translating terrestrial cell purification techniques to the ISS. Our evaluations were performed in microgravity conditions during parabolic atmospheric flight. The pipetting of open liquids in microgravity was evaluated using analog-blood fluids and several types of pipette hardware. The best-performing pipettors were used to evaluate the pipetting steps required for peripheral blood mononuclear cell (PBMC) isolation following terrestrial density-gradient centrifugation. Evaluation of actual blood products was performed for both the overlay of diluted blood, and the transfer of isolated PBMCs. We also validated magnetic purification of cells. We found that positive-displacement pipettors avoided air bubbles, and the tips allowed the strong surface tension of water, glycerol, and blood to maintain a patent meniscus and withstand robust pipetting in microgravity. These procedures will greatly increase the breadth of research that can be performed on board the ISS, and allow improvised experimentation by astronauts on extraterrestrial missions.