23 research outputs found

    Harnessing the immunomodulatory effects of exercise to enhance the efficacy of monoclonal antibody therapies against B-cell haematological cancers: a narrative review

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    Therapeutic monoclonal antibodies (mAbs) are standard care for many B-cell haematological cancers. The modes of action for these mAbs include: induction of cancer cell lysis by activating Fcγ-receptors on innate immune cells; opsonising target cells for antibody-dependent cellular cytotoxicity or phagocytosis, and/or triggering the classical complement pathway; the simultaneous binding of cancer cells with T-cells to create an immune synapse and activate perforin-mediated T-cell cytotoxicity against cancer cells; blockade of immune checkpoints to facilitate T-cell cytotoxicity against immunogenic cancer cell clones; and direct delivery of cytotoxic agents via internalisation of mAbs by target cells. While treatment regimens comprising mAb therapy can lead to durable anti-cancer responses, disease relapse is common due to failure of mAb therapy to eradicate minimal residual disease. Factors that limit mAb efficacy include: suboptimal effector cell frequencies, overt immune exhaustion and/or immune anergy, and survival of diffusely spread tumour cells in different stromal niches. In this review, we discuss how immunomodulatory changes arising from exposure to structured bouts of acute exercise might improve mAb treatment efficacy by augmenting (i) antibody-dependent cellular cytotoxicity, (ii) antibody-dependent cellular phagocytosis, (iii) complement-dependent cytotoxicity, (iv) T-cell cytotoxicity, and (v) direct delivery of cytotoxic agents

    The effects of sleep deprivation, acute hypoxia, and exercise on cognitive performance: A multi-experiment combined stressors study

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    Introduction: Both sleep deprivation and hypoxia have been shown to impair executive function. Conversely, moderate intensity exercise is known to improve executive function. In a multi-experiment study, we tested the hypotheses that moderate intensity exercise would ameliorate any decline in executive function after i) three consecutive nights of partial sleep deprivation (PSD) (Experiment 1) and ii) the isolated and combined effects of a single night of total sleep deprivation (TSD) and acute hypoxia (Experiment 2). Methods: Using a rigorous randomised controlled crossover design, 12 healthy participants volunteered in each experiment (24 total, 5 females). In both experiments seven executive function tasks (2-choice reaction time, logical relations, manikin, mathematical processing, 1-back, 2-back, 3-back) were completed at rest and during 20 min semi-recumbent, moderate intensity cycling. Tasks were completed in the following conditions: before and after three consecutive nights of PSD and habitual sleep (Experiment 1) and in normoxia and acute hypoxia (FIO2 = 0.12) following one night of habitual sleep and one night of TSD (Experiment 2). Results: Although the effects of three nights of PSD on executive functions were inconsistent, one night of TSD (regardless of hypoxic status) reduced executive functions. Significantly, regardless of sleep or hypoxic status, executive functions are improved during an acute bout of moderate intensity exercise. Conclusion: These novel data indicate that moderate intensity exercise improves executive function performance after both PSD and TSD, regardless of hypoxic status. The key determinants and/or mechanism(s) responsible for this improvement still need to be elucidated. Future work should seek to identify these mechanisms and translate these significant findings into occupational and skilled performance settings

    Causer, Adam J.

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    Uncertainties in breakup markers along the Iberia-Newfoundland margins illustrated by new seismic data

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    Plate tectonic modellers often rely on the identification of “break-up” markers to reconstruct the early stages of continental separation. Along the Iberian-Newfoundland margin, so-called break-up markers include interpretations of old magnetic anomalies from the M series, as well as the “J anomaly”. These have been used as the basis for plate tectonic reconstructions are based on the concept that these anomalies pinpoint the location of first oceanic lithosphere. However, uncertainties in the location and interpretation of break-up markers, as well as the difficulty in dating them precisely, has led to plate models that differ in both the timing and relative palaeo-positions of Iberia and Newfoundland during separation. We use newly available seismic data from the Southern Newfoundland Basin (SNB) to assess the suitability of commonly used break-up markers along the Newfoundland margin for plate kinematic reconstructions. Our data show that basement associated with the younger M-series magnetic anomalies is comprised of exhumed mantle and magmatic additions and most likely represents transitional domains and not true oceanic lithosphere. Because rifting propagated northward, we argue that M-series anomaly identifications further north, although in a region not imaged by our seismic, are also unlikely to be diagnostic of true oceanic crust beneath the SNB. Similarly, our data also allow us to show that the high amplitude of the J Anomaly is associated with a zone of exhumed mantle punctuated by significant volcanic additions and at times characterized by interbedded volcanics and sediments. Magmatic activity in the SNB at a time coinciding with M4 (128 Ma) and the presence of SDR packages onlapping onto a basement fault suggest that, at this time, plate divergence was still being accommodated by tectonic faulting. We illustrate the differences in the relative positions of Iberia and Newfoundland across published plate reconstructions and discuss how these are a direct consequence of the uncertainties introduced into the modelling procedure by the use of extended continental margin data (dubious magnetic anomaly identifications, break-up unconformity interpretations). We conclude that a different approach is needed for constraining plate kinematics of the Iberian plate pre-M0 times.</p

    Heat acclimation improves sweat gland function and lowers sweat sodium concentration in an adult with cystic fibrosis

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    We present novel data concerning the time-course of adaptations and potential benefits of heat acclimation for people with cystic fibrosis (pwCF), who are at greater risk of exertional heat illness. A 25-year-old male (genotype: delta-F508 and RH117, forced expiratory volume in 1-second: 77% predicted and baseline sweat [Na+]: 70 mmol·L − 1), who had previously experienced muscle cramping during exercise in ambient heat, underwent 10-sessions of heat acclimation (90-min at 40°C and in 40% relative humidity). Adaptations included; lower resting core temperature (-0.40°C) and heart rate (-6 beats·min−1), plasma volume expansion (+6.0%) and, importantly, increased sweat loss (+370 mL) and sweat gland activity (+12 glands·cm2) with decreased sweat [Na+] (-18 mmol·L − 1). Adaptations were maintained for at least 7-days, with no evidence of cramping during follow-up exercise-heat stress testing. These data suggest pwCF may benefit from heat acclimation to induce sudomotor function improvements, particularly reductions in sweat [Na+], however, further research is required

    A single bout of vigorous intensity exercise enhances the efficacy of rituximab against autologous human chronic lymphocytic leukaemia B-cells ex vivo

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    Chronic lymphocytic leukaemia (CLL) is characterised by the clonal proliferation and accumulation of mature B-cells and is often treated with rituximab, an anti-CD20 monoclonal antibody immunotherapy. Rituximab often fails to induce stringent disease eradication, due in part to failure of antibody-dependent cellular cytotoxicity which relies on natural killer (NK)-cells binding to rituximab-bound CD20 on B-cells. CLL cells are diffusely spread across lymphoid and other bodily tissues, and ADCC resistance in survival niches may be due to several factors including low NK-cell frequency and a suppressive stromal environment that promotes CLL cell survival. It is well established that exercise bouts induce a transient relocation of NK-cells and B-cells into peripheral blood, which could be harnessed to enhance the efficacy of rituximab in CLL by relocating both target and effector cells together with rituximab in blood. In this pilot study, n = 20 patients with treatment-naïve CLL completed a bout of cycling 15 % above their anaerobic threshold for ∼ 30-minutes, with blood samples collected pre-, immediately post-, and 1-hour post-exercise. Flow cytometry revealed that exercise evoked a 254 % increase in effector (CD3−CD56+CD16+) NK-cells in blood, respectively, and a 67 % increase in CD5+CD19+CD20+ CLL cells in blood (all p &lt; 0.005). NK-cells were isolated from blood samples pre-, and immediately post-exercise and incubated with primary isolated CLL cells with or without the presence of rituximab to determine specific lysis using a calcein-release assay. Rituximab-mediated cell lysis increased by 129 % following exercise (p &lt; 0.001). Direct NK-cell lysis of CLL cells – independent of rituximab – was unchanged following exercise (p = 0.25). We conclude that exercise improved the efficacy of rituximab-mediated antibody-dependent cellular cytotoxicity against autologous CLL cells ex vivo and propose that exercise should be explored as a means of enhancing clinical responses in patients receiving anti-CD20 immunotherapy

    A single bout of exercise enhances the efficacy of rituximab against autologous chronic lymphocytic leukaemia B cells <i>ex vivo</i> by transiently increasing natural killer cell frequency in blood, and simultaneously mobilises CD5 +CD19 +CD20 + B cells into blood

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    Chronic Lymphocytic Leukaemia (CLL) is characterised by the proliferation and accumulation of clonal B cells (B-CLL cells) and is often treated with anti-CD20 monoclonal antibody immunotherapies, including rituximab. One of the mechanism-of-action of rituximab is antibody-dependent cellular cytotoxicity (ADCC) which occurs when natural killer (NK) cells detect rituximab bound to CD20 + target cells. Rituximab often fails to induce stringent disease eradication, due in part to the diffuse distribution of clonal cells across multiple lymphoid and non-lymphoid tissues where NK cell frequency can be low. It is well established that an individual bout of aerobic exercise induces a transient relocation of lymphocytes - including NK cells and B cells - into peripheral blood. We hypothesised that this exercise-induced lymphocytosis could be harnessed to enhance the efficacy of rituximab in CLL by relocating both target and effector cells together with rituximab into blood.In this pilot study n = 20 treatment naïve patients with CLL (mean ± SD: age = 62 ± 10 years; height = 174.0 ± 7.5 cm; body mass = 83.3 ± 16.8 kg; body fat = 31.7 ± 9.8 %; blood leukocytes = 30.70 ± 22.21 ×10 9/L; anaerobic threshold = 14.1 ± 2.9 mL.kg -1.min -1) participated. Participants cycled at a moderate intensity (15% above their anaerobic threshold) for ~30-minutes, with blood samples collected pre-, post-, and 1-hour post-exercise.Given the importance of CD16 + NK cells in evoking ADCC, we enumerated NK cell subsets in blood samples collected pre, post-, and 1-hour post-exercise by flow cytometry. As expected, exercise induced a preferential increase of CD56 +CD16 + (+255%, p &lt; 0.001) and mature, cytotoxic CD56 +CD57 +CD16 + NK cells (+322%, p &lt; 0.001) pre- to post-exercise. Next, using immunomagnetic negative separation, NK cells and primary B-CLL cells were isolated from blood pre- and post-exercise and incubated together with heat inactivated foetal calf serum, with or without the presence of rituximab to determine specific lysis using a calcein-release assay. Rituximab mediated cell lysis increased by +129% following exercise ( p &lt; 0.001), with no change in antibody independent NK cell lysis of B-CLL cells - independent of rituximab - following exercise ( p = 0.25). Blocking CD16 on NK cells - vital for ADCC - blunted the effects of exercise on B-CLL cell lysis ( p = 0.84). In a subset of patients ( n = 9) we also explored the effects of autologous time-point matched plasma (instead of heat inactivated foetal calf serum) on rituximab mediated ADCC, which evoked a +92% increase in lysis pre- to post-exercise ( p = 0.038). Collectively, our results suggest that augmented efficacy of rituximab mediated ADCC was driven by an increase in CD16 + NK cells.We posited that the enhancement to rituximab mediated ADCC would have greater, clinically relevant implications if there was also a concomitant exercise-induced mobilisation of B-CLL cells expressing CD20 into blood from different body tissues. Flow cytometry revealed a +63% increase in CD5 +CD19 +CD20 + B-CLL cells ( p = 0.002) in blood after exercise. Further analyses revealed that CD5 +CD19 +CD20 + B-CLL cells with a phenotype consistent with recent egress from lymphoid tissue (CD5 brightCXCR4 dim; 70%, p = 0.004) and B-CLL cells with a propensity to migrate to peripheral tissues (CD5 dimCXCR4 bright; 67%, p = 0.002) were mobilised, with no change to overall CD20 surface antigen density ( p = 1.0) - determined by median fluorescence intensity. Furthermore, exercise evoked a +69% ( p = 0.022) increase in CD5 +CD19 +CD20 + B-CLL cells expressing CD49d, which is considered one of the strongest predictors of CLL prognosis. Taken together, these data demonstrate that exercise increased the frequency of CD20 + B-CLL cells with lymphoid origins and prognostic relevance into the blood, therefore rendering them susceptible to rituximab mediated ADCC.Our results show that individual bouts of moderate intensity aerobic exercise temporarily increased the number of cytotoxic CD16 + NK cells, and CD20 + B-CLL cells in blood. Additionally, our ex vivo investigations demonstrated enhanced rituximab mediated ADCC following exercise. Thus, exercise could be explored as a means of improving clinical responses in patients receiving rituximab, and/or other anti-CD20 monoclonal antibodies such as, Obinutuzumab
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