Human lymphocytes mobilized with exercise have an anti-tumor transcriptomic profile and exert enhanced graft-versus-leukemia effects in xenogeneic mice

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

Antiviral treatment with valacyclovir reduces virus shedding in saliva of Antarctic expeditioners

IntroductionReactivation of herpes viruses, such as Epstein–Barr virus (EBV), herpes simplex virus 1 (HSV1), and varicella zoster virus (VZV), increases in astronauts during spaceflight, compared with their preflight and postflight levels. Reactivations can increase the risk of associated clinical conditions, such as herpes zoster, chronic neuropathic pain, vision loss, stroke, cognitive impairment, and cold sores. Furthermore, continued viral shedding for longer periods after space travel may increase the risk of viral transmission to uninfected crew contacts, including, but not limited to, the immunocompromised and newborn infants. Thus, it is essential to develop spaceflight countermeasures to prevent herpes viral reactivations to ensure the health of crewmembers and their contacts. One such countermeasure is the prophylactic administration of an antiviral drug (valacyclovir) against the alpha herpesviruses (VZV and HSV1). To determine the effectiveness of this countermeasure, we studied the shedding of EBV, VZV, and HSV1 in Antarctic expeditioners, who have similar salivary viral shedding patterns during winter-over to astronauts during long spaceflights.MethodsThe efficacy of this antiviral drug as a countermeasure was determined using three major parameters in the saliva of expeditioners during winter-over with and without administration of this drug: (i) viral load and frequency, (ii) physiological stress biomarkers [i.e., levels of cortisol, dehydroepiandrosterone (DHEA), and amylase), and (iii) immune markers (i.e., inflammatory cytokines)]. Thirty-two volunteers from two Antarctic stations (McMurdo and South Pole) participated in this study. Participants were randomly assigned to either the treatment group (valacyclovir HCl: 1 g/day) or placebo group (oyster calcium: 500mg/day). ResultsViral shedding of EBV reduced significantly (> 24-fold) in the treatment group compared with the placebo group. HSV1 was also reduced by more than fivefold, but this was not statistically significant. No VZV shedding was observed in any of the participants. In the placebo group 50% of the saliva samples had measurable viral DNA (EBV, HSV1, or both), compared with 19% of the treatment group. There was no significant change in the ratio of cortisol to DHEA or levels of alpha-amylase, indicating that physiological stress was similar between the groups. No difference was detected in levels of salivary cytokines, except IL-10, which was found in significantly lower levels in the treatment group. DiscussionThese data indicate that valacyclovir is a safe and successful intervention to reduce EBV and HSV1 shedding in individuals subjected to extreme environments and stressors

The Effect Of Human Peripheral Blood Mononuclear Cells Mobilized By Acute Exercise On Graft-Versus-Host Disease And Graft-Versus-Leukemia In A Humanized Mouse Model

Hematopoietic cell transplantation and adoptive transfer immunotherapy are critical therapeutic options for patients with hematological malignancies. The lymphocyte composition of the donor graft is known to influence the potentially fatal graft-versus-host disease (GvHD) and the potentially curative graft-versus-tumor (GvT) effects. Increased numbers of NK-cells and γδ T-cells relative to naïve subsets of CD4+ and CD8+ αβ T-cells have been shown to evoke strong GvT effects with minimal GvHD. As single exercise bouts are known to produce these desirable shifts in lymphocyte subset composition, we hypothesized that human immune cells collected from a single bout of exercise will improve engraftment, GvHD, and GvT outcomes when compared to immune cells from rest when xenotransplanted to immunodeficient mice. This dissertation was divided into two specific hypotheses: 1) determine the effect of PBMCs collected during exercise on engraftment and GvHD in a humanized mouse model; and 2) determine the impact of PBMCs collected during exercise on GvT in a humanized mouse model. To test these hypotheses, 12 healthy adults completed a 30-minute bout of exercise that was 15% about their calculated ventilatory threshold. Blood was collected at rest and immediately prior to exercise cessation. Lymphocyte subtypes were determined by flow cytometry prior to transplant. 1 x 107 Human PBMCs and/or 1 x 106 human K562-luc2 leukemia cells were injected intravenously into 8-12 week old NOD.Cg-Prkdcscid Il2rgtm1Wjl Tg(IL15)1Sz/SzJ (NSG-Tg(Hu-IL15) or NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG). Engraftment of human immune cells was tracked weekly, while morbidity scoring and bioluminescence imaging was conducted twice per week for up to 40 days. In support of the hypotheses, tumor-bearing NSGIL-15 mice injected with PBMCs from exercise maintained increased percentages of NK cells and decreased percentages of CD4+ T cells for up to two weeks post-inoculation. Additionally, these mice displayed overall better survival, delayed severe morbidity (GvHD), and an overall reduction in tumor growth compared to mice injected with PBMCs collected from rest. However, improvements in engraftment, morbidity, and survival were not replicated in mouse models of mild or severe GvHD indicating that tumor activation of exercise immune cells was essential for improved outcomes compared to immune cells taken from rest. We conclude that exercising donors prior to transplants can improve disease outcomes for hematopoietic cell transplantations in cancer immunotherapies

Dermatitis during Spaceflight Associated with HSV-1 Reactivation

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

Immune system dysregulation preceding a case of laboratory-confirmed zoster/dermatitis on board the International Space Station

A case report detailing, for the first time, a case of laboratory-confirmed zoster in an astronaut on board the International Space Station is presented. The findings of reduced T-cell function, cytokine imbalance, and increased stress hormones which preceded the event are detailed. Relevance for deep space countermeasures is discussed