Genetic variability has a profound effect on the development of cardiac hypertrophy in response to stress. Consequently, using a variety of inbred mouse strains with known genetic profiles may be powerful models for studying the response to cardiovascular stress. To explore this approach we looked at male C57BL/6J and 129/SvJ mice. Hemodynamic analyses of left ventricular pressures (LVPs) indicated significant differences in 129/SvJ and C57BL/6J mice that implied altered Ca2+ handling. Specifically, 129/SvJ mice demonstrated reduced rates of relaxation and insensitivity to dobutamine (Db). We hypothesized that altered expression of genes controlling the influx and efflux of Ca2+ from the sarcoplasmic reticulum (SR) was responsible and investigated the expression of several genes involved in maintaining the intracellular and sarcoluminal Ca2+ concentration using quantitative real-time PCR analyses (qRT-PCR). We observed significant differences in baseline gene expression as well as different responses in expression to isoproterenol (ISO) challenge. In untreated control animals, 129/SvJ mice expressed 1.68× more ryanodine receptor 2(Ryr2) mRNA than C57BL/6J mice but only 0.37× as much calsequestrin 2 (Casq2). After treatment with ISO, sarco(endo)plasmic reticulum Ca2+-ATPase(Serca2) expression was reduced nearly two-fold in 129/SvJ while expression in C57BL/6J was stable. Interestingly, β (1) adrenergic receptor(Adrb1) expression was lower in 129/SvJ compared to C57BL/6J at baseline and lower in both strains after treatment. Metabolically, the brain isoform of creatine kinase (Ckb) was up-regulated in response to ISO in C57BL/6J but not in 129/SvJ. These data suggest that the two strains of mice regulate Ca2+ homeostasis via different mechanisms and may be useful in developing personalized therapies in human patients.

Human alpha herpesviruses herpes simplex virus (HSV-1) and varicella zoster virus (VZV) establish latency in various cranial nerve ganglia and often reactivate in response to stress-associated immune system dysregulation. Reactivation of Epstein Barr virus (EBV), VZV, HSV-1, and cytomegalovirus (CMV) is typically asymptomatic during spaceflight, though live/infectious virus has been recovered and the shedding rate increases with mission duration. The risk of clinical disease, therefore, may increase for astronauts assigned to extended missions (>180 days). Here, we report, for the first time, a case of HSV-1 skin rash (dermatitis) occurring during long-duration spaceflight. The astronaut reported persistent dermatitis during flight, which was treated onboard with oral antihistamines and topical/oral steroids. No HSV-1 DNA was detected in 6-month pre-mission saliva samples, but on flight day 82, a saliva and rash swab both yielded 4.8 copies/ng DNA and 5.3 × 104 copies/ng DNA, respectively. Post-mission saliva samples continued to have a high infectious HSV-1 load (1.67 × 107 copies/ng DNA). HSV-1 from both rash and saliva samples had 99.9% genotype homology. Additional physiological monitoring, including stress biomarkers (cortisol, dehydroepiandrosterone (DHEA), and salivary amylase), immune markers (adaptive regulatory and inflammatory plasma cytokines), and biochemical profile markers, including vitamin/mineral status and bone metabolism, are also presented for this case. These data highlight an atypical presentation of HSV-1 during spaceflight and underscore the importance of viral screening during clinical evaluations of in-flight dermatitis to determine viral etiology and guide treatment.

BackgroundEvery bout of exercise mobilizes and redistributes large numbers of effector lymphocytes with a cytotoxic and tissue migration phenotype. The frequent redistribution of these cells is purported to increase immune surveillance and play a mechanistic role in reducing cancer risk and slowing tumor progression in physically active cancer survivors. Our aim was to provide the first detailed single cell transcriptomic analysis of exercise-mobilized lymphocytes and test their effectiveness as a donor lymphocyte infusion (DLI) in xenogeneic mice engrafted with human leukemia.MethodsPeripheral blood mononuclear cells (PBMCs) were collected from healthy volunteers at rest and at the end of an acute bout of cycling exercise. Flow cytometry and single-cell RNA sequencing was performed to identify phenotypic and transcriptomic differences between resting and exercise-mobilized cells using a targeted gene expression panel curated for human immunology. PBMCs were injected into the tail vein of xenogeneic NSG-IL-15 mice and subsequently challenged with a luciferase tagged chronic myelogenous leukemia cell line (K562). Tumor growth (bioluminescence) and xenogeneic graft-versus-host disease (GvHD) were monitored bi-weekly for 40-days.ResultsExercise preferentially mobilized NK-cell, CD8+ T-cell and monocyte subtypes with a differentiated and effector phenotype, without significantly mobilizing CD4+ regulatory T-cells. Mobilized effector lymphocytes, particularly effector-memory CD8+ T-cells and NK-cells, displayed differentially expressed genes and enriched gene sets associated with anti-tumor activity, including cytotoxicity, migration/chemotaxis, antigen binding, cytokine responsiveness and alloreactivity (e.g. graft-versus-host/leukemia). Mice receiving exercise-mobilized PBMCs had lower tumor burden and higher overall survival (4.14E+08 photons/s and 47%, respectively) at day 40 compared to mice receiving resting PBMCs (12.1E+08 photons/s and 22%, respectively) from the same donors (p<0.05). Human immune cell engraftment was similar for resting and exercise-mobilized DLI. However, when compared to non-tumor bearing mice, K562 increased the expansion of NK-cell and CD3+/CD4-/CD8- T-cells in mice receiving exercise-mobilized but not resting lymphocytes, 1-2 weeks after DLI. No differences in GvHD or GvHD-free survival was observed between groups either with or without K562 challenge.ConclusionExercise in humans mobilizes effector lymphocytes with an anti-tumor transcriptomic profile and their use as DLI extends survival and enhances the graft-versus-leukemia (GvL) effect without exacerbating GvHD in human leukemia bearing xenogeneic mice. Exercise may serve as an effective and economical adjuvant to increase the GvL effects of allogeneic cell therapies without intensifying GvHD.

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Background:We have previously shown that the anti-tumor activity of human lymphocytes is diminished in vitro after 12-hours preexposure to simulated microgravity (SMG). Here we used an immunocompromised mouse model to determine if this loss of function would extend in vivo, and to also test the efficacy of IL-2 and zoledronic acid (ZOL) therapy as a potential countermeasure against SMG-induced immune dysfunction. We adoptively transferred human lymphocytes that were exposed to either SMG or 1G-control into NSG-Tg (Hu-IL15) mice 1-week after they were injected with a luciferase-tagged human chronic myeloid leukemia (K562) cell line. Tumor growth was monitored 2x weekly with bioluminescence imaging (BLI) for up to 6-weeks. Results: Mice that received lymphocytes exposed to SMG showed greater tumor burden compared to those receiving lymphocytes exposed to 1G (week 6 BLI: 1.8e 10 ± 8.07e 9 versus 2.22e 8 ± 1.39e 8 photons/second; p < 0.0001). Peak BLI was also higher in the SMG group compared to 1Gcontrol (2.34e 10 ± 1.23e 10 versus 3.75e 8 ± 1.56e 8 photons/second; p = 0.0062). Exposure to SMG did not affect the ability of human lymphocytes to engraft or evoke xeno-graft-versus-host disease in the mice. Additionally, we injected the mice with IL-2 and zoledronic acid (ZOL) to expand and activate the anti-tumor activity of NK cells and γδ-T cells, respectively. This treatment was found to revive the loss of anti-leukemic function observed in vivo when lymphocytes were pre-exposed to SMG. Conclusions: Microgravity plays a contributory role in loss of tumor control in vivo. Immuno-stimulating agents like ZOL+IL-2 may offer an important countermeasure for immune dysregulation during prolonged spaceflight.