Mast cells are upregulated in hidradenitis suppurativa tissue, associated with epithelialized tunnels and normalized by spleen tyrosine kinase antagonism.

Mast cells have traditionally been associated with allergic inflammatory responses; however, they play important roles in cutaneous innate immunity and wound healing. The Hidradenitis Suppurativa tissue transcriptome is associated with alterations in innate immunity and wound healing-associated pathways; however, the role of mast cells in the disease is unexplored. We demonstrate that mast cell-associated gene expression (using whole tissue RNAseq) is upregulated, and in-silico cellular deconvolution identifies activated mast cells upregulated and resting mast cells downregulated in lesional tissue. Tryptase/Chymase positive mast cells (identified using IHC) localize adjacent to epithelialized tunnels, fibrotic regions of the dermis and at perivascular sites associated with Neutrophil Extracellular Trap formation and TNF-alpha production. Treatment with Spleen Tyrosine Kinase antagonist (Fostamatinib) reduces the expression of mast cell-associated gene transcripts, associated biochemical pathways and the number of tryptase/chymase positive mast cells in lesional hidradenitis suppurativa tissue. This data indicates that although mast cells are not the most abundant cell type in Hidradenitis Suppurativa tissue, the dysregulation of mast cells is paralleled with B cell/plasma cell inflammation, inflammatory epithelialized tunnels and epithelial budding. This provides an explanation as to the mixed inflammatory activation signature seen in HS, the correlation with dysregulated wound healing and potential pathways involved in the development of epithelialized tunnels.

Plasma ropivacaine concentrations during bilateral transversus abdominis plane infusions.

BACKGROUND: The transversus abdominis plane (TAP) block is a regional anaesthetic technique that blocks abdominal wall somatic afferent nerves. We conducted a prospective observational study to evaluate the venous plasma concentrations of ropivacaine during a continuous TAP infusion. METHODS: Twenty patients who were planned to undergo intra-abdominal cavity surgery requiring a mid-line laparotomy incision were enrolled. Patients were excluded if they had a history of chronic pain, opioid tolerance, renal or hepatic impairment, or contraindication to study medications. Subjects received a standardized general anaesthetic, and at the completion of surgery, ultrasound-guided subcostal or posterior TAP blocks and catheters. A TAP infusion of 2 mg ml(-1) ropivacaine was administered for 72 h after operation. Data collection during the 72 h included morphine requirements, pain scores, and plasma ropivacaine levels. RESULTS: TAP blocks and catheters were successfully inserted in all recruited subjects. The fourth subject experienced neurological symptoms attributed to local anaesthetic toxicity, but did not have high plasma ropivacaine concentrations. However, the protocol was amended for the subsequent 16 subjects, to a weight-based dosing regimen. The range of total plasma ropivacaine concentrations was 0.98-3.41 mg litre(-1) for posterior infusions and 0.96-3.48 mg litre(-1) for subcostal infusions. Four subjects had total ropivacaine levels >3.4 mg litre(-1). The range of unbound plasma ropivacaine concentrations was 0.022-0.135 mg litre(-1) for posterior infusions and 0.031-0.120 mg litre(-1) for subcostal infusions. CONCLUSION: Given the potential for high plasma concentrations from a bilateral TAP infusion technique, attention should be paid to individualized dosing strategies.

Effect of sex on wasted left ventricular effort following maximal exercise.

Wasted left ventricular effort (∆Ew) refers to work required of the left ventricle to eject blood that does not result in increased stroke volume and is related to left ventricular hypertrophy. Literature shows that men and women have differing ventricular and vascular responses to and following exercise. Our purpose was to determine how ∆Ew changes post-exercise in men and women and examine potential mechanisms. We hypothesized a reduction in ∆Ew that would be greater in men and that central pulse wave velocity and wave intensity (WIA) would be related to ∆Ew. Blood pressures, central pulse wave velocity (cPWV), and WIA were obtained at rest, 15 and 30 min after maximal exercise. Both sexes reduced ∆Ew post-maximal exercise (p>0.05 for interaction), but women had higher ∆Ew at each time point (p<0.05). The first peak of WIA increased 15 min post-exercise only in women (p<0.05). cPWV was attenuated (p<0.05) in women at 15 min and men at 30 min (p<0.05) post-exercise with a significant time by sex interaction (p<0.05). WIA (1st peak) was correlated (p<0.05) to ∆Ew in both sexes before and 15 min post-exercise, but cPWV was only associated with ∆Ew in men at 30 min post-exercise. We conclude that both sexes decrease ∆Ew after maximal exercise, but vascular and ventricular changes associated with the attenuation of ∆Ew are not uniform between sexes.

Ultraviolet A1 phototherapy: a British Photodermatology Group workshop report.

Whole-body ultraviolet (UV)A1 (340-400 nm) phototherapy was first introduced 30 years ago, but is currently available in the UK in only three dermatology departments. A workshop to discuss UVA1 was held by the British Photodermatology Group in May 2009, the aim of which was to provide an overview of UVA1 phototherapy and its role in practice, and to identify areas in which further studies are required. The conclusions were that UVA1 phototherapy is an effective treatment in several inflammatory skin diseases, including localized scleroderma and atopic eczema (AE); however, deficiencies and limitations exist in the published evidence base. For most diseases, such as AE, other treatments also exist, which are generally more effective than UVA1. However, for some diseases, particularly morphoea, the evidence of efficacy is stronger for UVA1 than for other treatments. Acute adverse effects of UVA1 are minimal. The risk of long-term adverse effects, particularly skin cancer, is unknown. Medium to high doses of UVA1 are needed for efficacy in most situations, but the equipment to deliver such doses is large, expensive and difficult to install. UVA1 is currently underprovided, and the recommendation of the workshop is that more tertiary centres should have access to UVA1 phototherapy in the UK.

Reduction in trunk fat predicts cardiovascular exercise training-related reductions in C-reactive protein.

C-reactive protein (CRP) is an independent risk factor for cardiovascular disease. We sought to determine (1) if 10 months of cardiovascular exercise training (Cardio) reduces CRP in a group of older adults, (2) if such a reduction is related to improvements in trunk fat, fitness, and/or psychosocial variables, and (3) if the effect of Cardio on CRP differs between men and women. Community-dwelling residents (n=127; 60-83 yrs) were randomized to a Flex group (n=61) where they participated in 2-75 min supervised sessions per wk during which they performed non-cardiovascular flexibility and balance exercises or a Cardio group (n=66) where they participated in three supervised sessions per wk during which they performed cardiovascular exercises for approximately 45-60 min at 60-70% maximal oxygen uptake. The main outcome measures were serum CRP, cardiovascular fitness, total and central adiposity, and self-reported psychosocial function. Cardio experienced a reduction in CRP (-0.5mg/L), as well as improvements in fitness (+7%) and total (-1.5%) and central (i.e., trunk) (-2.5%) adiposity. These relationships were not modified by sex. Regression analyses indicated that only the reduction in trunk fat was significantly related to the reduction in CRP. Ten months of cardiovascular exercise training reduced CRP in previously sedentary older adults and this effect was partially mediated by a reduction in trunk fat.

Satellite radiation measurements and clear air turbulence probability.

Radiance gradients determined from data gathered by the infrared spectrometers aboard the Nimbus III and Nimbus IV satellites were related to the probabilities of clear air turbulence, as inferred from regular pilot reports. Such radiance gradients represent rather large-scale vertical wind shear. Clear air turbulence is least likely in regions where the radiance gradient is small. The results of this exploratory study show that satellite data can be used to design flight paths so that the probability of encountering clear air turbulence is extremely small.

Cardiovascular exercise intervention improves the primary antibody response to keyhole limpet hemocyanin (KLH) in previously sedentary older adults.

Based upon a prior cross-sectional study, we hypothesized that an aerobic exercise intervention in sedentary older adults would improve a primary T cell-dependent immune response. Participants were a subset of older subjects from a large, ongoing exercise intervention study who were randomly assigned to either an aerobic exercise (Cardio, n=30, 68.9+0.8 years) or flexibility/balance (Flex, n=20, 69.9+1.2 years) intervention. The intervention consisted of either three aerobic sessions for 30-60 min at 55-70% VO(2 max) or two 60 min flexibility/balance sessions weekly for 10 months. Eight months into the intervention, samples were collected before intramuscular administration of KLH (125 microg), followed by sampling at 2, 3, and 6 weeks post-KLH. Serum anti-KLH IgM, IgG1, and IgG2 was measured by ELISA. Physiological and psychosocial measures were also assessed pre- and post-intervention. While there was no difference in the anti-KLH IgG2 response between groups, Cardio displayed significantly (p<0.05) higher anti-KLH IgG1 (at weeks 2, 3, and 6 post) and IgM responses when compared to Flex. Despite cardiovascular intervention-induced improvement in physical fitness (approximately 11% vs. 1% change in VO(2 peak) in Cardio vs. Flex, respectively), we found no relationship between improved fitness and enhanced anti-KLH antibody responses. Optimism, perceived stress, and affect were all associated with enhanced immune response. We have shown for the first time that cardiovascular training in previously sedentary elderly results in significantly higher primary IgG1 and IgM antibody responses, while having no effect on IgG2 production.

Exercise training-induced modification of the gut microbiota persists after microbiota colonization and attenuates the response to chemically-induced colitis in gnotobiotic mice.

Exercise reduces the risk of inflammatory disease by modulating a variety of tissue and cell types, including those within the gastrointestinal tract. Recent data indicates that exercise can also alter the gut microbiota, but little is known as to whether these changes affect host function. Here, we use a germ-free (GF) animal model to test whether exercise-induced modifications in the gut microbiota can directly affect host responses to microbiota colonization and chemically-induced colitis. Donor mice (n = 19) received access to a running wheel (n = 10) or remained without access (n = 9) for a period of six weeks. After euthanasia, cecal contents were pooled by activity treatment and transplanted into two separate cohorts of GF mice. Two experiments were then conducted. First, mice were euthanized five weeks after the microbiota transplant and tissues were collected for analysis. A second cohort of GF mice were colonized by donor microbiotas for four weeks before dextran-sodium-sulfate was administered to induce acute colitis, after which mice were euthanized for tissue analysis. We observed that microbial transplants from donor (exercised or control) mice led to differences in microbiota ß-diversity, metabolite profiles, colon inflammation, and body mass in recipient mice five weeks after colonization. We also demonstrate that colonization of mice with a gut microbiota from exercise-trained mice led to an attenuated response to chemical colitis, evidenced by reduced colon shortening, attenuated mucus depletion and augmented expression of cytokines involved in tissue regeneration. Exercise-induced modifications in the gut microbiota can mediate host-microbial interactions with potentially beneficial outcomes for the host.

The acute effects of streptozotocin-induced diabetes on rat liver glycerolipid biosynthesis.

Streptozotocin-induced diabetes produced a significant rise in rat serum and liver triacylglycerol content and hepatic triacylglycerol biosynthesis measured in vivo. Microsomes, isolated from the livers of streptozotocin-exposed animals (2-72h), exhibited an increased capacity to incorporate sn-[1,3-(14)C]glycerol 3-phosphate into neutral lipid (diacylglycerol and triacylglycerol) in the presence of ATP, CoA and palmitate. The streptozotocin-induced elevation of microsomal neutral lipid production was accompanied by a corresponding rise in the activity of microsomal phosphatidate phosphohydrolase (4-fold after 72 h of streptozotocin exposure). Diabetic-dependent increases in acylglycerol formation, phosphatidate phosphohydrolase activity and serum triacylglycerol and fatty acid levels were reversed by administering insulin (10 units protamine zinc/kg) at 16-h intervals (three separate doses( beginning 24 h after streptozotocin exposure. However, the diabetic-related rise in hepatic triacylglycerol content was only partially corrected by insulin administration. Streptozotocin-relate increases in liver triacylglycerol biosynthesis and phosphatidate phosphohydrolase activity we associated with alterations in plasma factors, since homogenates of hepatocyte monolayers exposed (18h) to plasma isolated from diabetic (72 h exposure to streptozotocin) animals exhibit an increased capacity to incorporate sn-[1,3-(14)C]glycerol 3-phosphate into triacylglycerol compared to homogenates of cells exposed to plasma from control (non-fasted) animals. The importance of these plasma factors in altering hepatic acylglycerol formation was also supported by the observation that hepatocyte monolayers exposed to a mixture of plasma isolated from normal (non-fasted) animals and plasma components elevated in diabetes (glucagon, glucose, oleate and ketones) showed increases in triacylglycerol formation which were similar to those produced by exposure to diabetic plasma. Additional studies demonstrated that fatty acids (oleate) appeared to be the agent primarily responsible for the diabetic plasma-induced rise in monolayer triacylglycerol biosynthesis and phosphatidate phosphohydrolase activity.

Photogenotoxicity of hypericin in HaCaT keratinocytes: implications for St. John's Wort supplements and high dose UVA-1 therapy.

Extract of St. John's Wort (Hypericum perforatum) is commonly used as natural remedy for treatment of mild to moderate depression. However, it contains a powerful photoactive component, hypericin, which can cause a severe photodermatitis when eaten by grazing animals (hypericism). In humans, there is evidence that supplementation with St. John's Wort can reduce the minimal erythemal dose (MED) in patients undergoing high dose UVA-1 phototherapy. This is a recent development in phototherapy where the most erythemogenic parts of the UVA spectrum are filtered out, allowing delivery of higher doses of the longer wavelengths of UVA. Although current published evidence suggests that the plasma levels of hypericin are unlikely to cause clinical phototoxicity, it has been established that photoactive compounds can cause DNA damage at sub-toxic and sub-erythemal doses, the effects of which might not be apparent for many years after the event. The present study used HaCaT keratinocytes to investigate the photoclastogenic ability of hypericin on irradiation with UVA. The results show that although the combination of hypericin and UVA light increased the genotoxic burden, when all factors are taken into account, the risk of significant photogenotoxic damage incurred by the combination of Hypericum extracts and UVA phototherapy may be low in the majority of individuals.

The phototoxicity of vemurafenib: An investigation of clinical monochromator phototesting and in vitro phototoxicity testing.

BACKGROUND: Vemurafenib is a targeted therapy approved for the treatment of patients with metastatic melanoma harbouring the BRAF V600E mutation. Photosensitivity has been reported in over 50% of patients and has been demonstrated to involve at least the broadband UVA spectrum in most patients. Erythrocyte protoporphyrin levels have also been reported as elevated in some patients. OBJECTIVES: We report the results of monochromator phototesting in one patient recorded before and while taking vemurafenib. Analysis of porphyrin levels was also conducted. RESULTS: After one month of vemurafenib therapy the patient demonstrated markedly increased light sensitivity in the UVA spectrum between 335 ± 27 nm, 365 ± 27 nm and 400 ± 27 nm. However responses in the UVB (305 ± 5 nm) and blue light (430 ± 27 nm) regions were normal. There was no abnormal immediate erythemal response. Pre-vemurafenib baseline phototesting was normal, as was repeat testing two months later when the patient was taking high doses of systemic steroid. No abnormal porphyrins were detected and the antinuclear antibody test was normal. In parallel studies, HaCaT keratinocytes incubated with vemurafenib were killed by UVA but not by visible (blue) light and did not show evidence of detectable intracellular porphyrin in the presence of the drug. CONCLUSION: These data confirm vemurafenib induced UVA photosensitivity with a probable phototoxic mechanism not mediated via enhanced porphyrin.

Beta-carotene enhances hydrogen peroxide-induced DNA damage in human hepatocellular HepG2 cells.

In this study, the alkaline version of the comet assay has been used to determine the effect of beta-carotene supplementation (10 microM) on peroxide-initiated free radical-mediated DNA damage in human HepG2 hepatoma cells. In supplemented cells, beta-carotene failed to afford any protection against hydrogen peroxide-induced DNA strand breaks. Indeed, levels of strand breaks in supplemented cells were significantly higher than in cells exposed to hydrogen peroxide alone, especially after a long incubation period. In contrast, beta-carotene afforded significant levels of protection against DNA strand breaks when cells were treated with tert-butyl hydroperoxide. In this case, the level of protection increased as supplementation continued.

Macrophage hypo-responsiveness to interferon-gamma in aged mice is associated with impaired signaling through Jak-STAT.

Since macrophages (Mphis) are a first line of defense against pathogens, and are involved in both innate and adaptive immunity, understanding the impact of aging on Mphi function is important. In the past studies, we and others have shown that aging decreases Mphi responsiveness to classical activating signals (e.g. IFN-gamma and lipopolysaccharide, LPS). In this study, we examined the impact of aging on Mphi signaling through the IFN-gamma receptor pathway. Mphis from male Balb/c mice aged 2 (young) and 18-24 (old) months were purified and then stimulated with IFN-gamma. Western blotting revealed a significant reduction ( approximately 50%) in IFN-gamma-stimulated tyrosine phosphorylation of signal transducer and activator of transcription-1 (STAT-1) alpha and beta in Mphis from aged, when compared with young mice. This reduction in phospho-STAT-1 was associated with a significant constitutive reduction ( approximately 80%) in total STAT-1alpha protein and a complete inhibition of STAT-1 gene expression in response to IFN-gamma in old compared to young mice. These data may, in part, explain why classical Mphi responses like reactive nitrogen and oxygen species generation, tumor killing and microbicidal activity are lower in Mphis from aged subjects. We conclude that peritoneal Mphis from aged mice have an intrinsic defect in Jak-STAT signaling which prevents them from fully responding to IFN-gamma.

Effects of 6 months of moderate aerobic exercise training on immune function in the elderly.

The purpose of this study was to determine the effects of 6 months of moderate aerobic exercise on age-dysregulated measures of T lymphocyte and natural killer (NK) cell number and function. Previously sedentary elderly (age = 65 +/- 0.8 years) subjects were randomly assigned to supervised 3 time/week exercise intervention group (EXC, n = 14) or flexibility/toning control group (FT-CON, n = 15). Fasting resting blood samples were drawn prior to and after the 6 month intervention. The EXC group exhibited a significant (P < 0.05) 20% increase in VO2 max, whereas the FT-CON group had a smaller non-significant (P = 0.07) increase (9%). Immune results revealed that, in general, changes in immune function in response to 6 months of exercise training at an average intensity of 52% heart rate reserve (HRR) were similar when compared to FT-CON who exercised at approximately 21% HRR. There were no intervention-induced changes in total white blood cell, neutrophil, lymphocyte, monocyte, eosinophil, or basophil blood counts. Furthermore, the percentage and number of CD3+, CD4+ and CD8+ T cells in the blood remained unchanged. There was a tendency for the percentage and number of CD4+ and CD8+ näive cells (CD45RA+) to increase and for CD4+ memory cells (CD45RO+) to decrease post-intervention, especially in FT-CON. Both groups exhibited a small intervention-induced increase in the T-cell proliferative response to mitogenic stimulation: the percentage change of which was higher in the EXC group at several doses of Con A. Unstimulated NK cell cytolysis versus K562 cells tended to increase (P < 0.1) in the EXC group with little change in FT-CON. We conclude that 6 months of supervised exercise training can lead to nominal increases in some measures of immune function, while not affecting others, in previously sedentary elderly.

Limitations of the single-cell gel electrophoresis assay to monitor apoptosis in U937 and HepG2 cells exposed to 7beta-hydroxycholesterol.

The single-cell gel electrophoresis (comet) assay is a method which allows the detection of DNA strand breaks in individual cells. It has been suggested that the single cell gel electrophoresis assay, as an index of DNA fragmentation during cell death, may be applied to monitor apoptosis. The aim of the present study was to determine if the pattern of DNA fragmentation determined by the single cell gel electrophoresis assay can be used to discriminate between the mode of cell death in two cell lines (U937, a human monocytic blood cell line and HepG2, a human hepatocarcinoma cell line) which were treated with 30 microM 7beta-hydroxycholesterol (7betaOHC) over a 48 hr period. The single cell gel electrophoresis assay was compared with more established methods for the determination of apoptosis such as morphological examination, flow cytometry and DNA laddering. The percentage of maximally damaged nuclei as measured by the single cell gel electrophoresis assay was found to be similar at 48 hr in both U937 and HepG2 cells when treated with 7betaOHC. However, morphological examination, flow cytometry and DNA laddering techniques showed that 7betaOHC induced apoptosis in U937 cells but not in HepG2 cells. Thus, although the alkaline single cell gel electrophoresis assay detected DNA strand breaks occurring during cell death, these breaks were observed only when the process was fairly well advanced and a major part of the cells had lost membrane permeability. Therefore the present report demonstrates that the single cell gel electrophoresis assay, used in isolation, cannot accurately be used to distinguish between the mode of cell death induced by 7betaOHC in U937 cells (apoptosis), or HepG2 cells (cell lysis).

Effects of maximal exercise on natural killer (NK) cell cytotoxicity and responsiveness to interferon-alpha in the young and old.

We investigated the effects of a graded maximal exercise treadmill test on natural killer (NK) cell number, activity, and responsiveness to interferon-alpha (IFN-alpha) in young (22+/-0.7 yrs) and elderly (65+/-0.8 yrs) sedentary subjects. NK cell cytotoxicity (NKCC) was determined using Ficoll purified peripheral blood mononuclear cells (PBMCs) by a 51Cr release assay against NK-sensitive (K562) and NK-insensitive (Daudi) target cells at various effector:target (E:T) ratios before and immediately after exercise. PBMCs were incubated with rhu IFN-alpha (125 and 250u/10(6) PBMCs) or without for 2 hrs before addition to the 51Cr release assay. There were no differences in unstimulated NKCC against K562 or Daudi targets between the old and the young despite significantly (p=.01) higher percentages of CD56+ NK cells (21.1+/-2.3% in old vs 12.5+/-2.5% in young, pre-exercise). IFN-alpha increased NKCC versus both targets, and NK cells from old subjects were hyporesponsive to IFN-alpha stimulation; this was especially evident at low E:T ratios versus Daudi cells. Maximal exercise significantly increased (50-200%) unstimulated NKCC versus K562 and Daudi targets similarly in both young and old and increased the percentage of CD56+ cells in the PBMC fraction to 33.3+/-3.7% and 23.3+/-3.6% in old and young, respectively. We found a significant correlation between %CD56+ and basal NKCC versus K562s and Daudi cells in the young (i.e., r=.55; p=.02 vs K562s), but not the old (i.e., r=.20; p=.29 vs K562s) subjects. This indicates that, in the young, part of the exercise-induced increase in NKCC is due to an increase in NK cell number. Maximal exercise did not affect unstimulated per cell killing of K562s, but tended to increase per cell killing of Daudis. These results indicate that CD56+ cells from old subjects have an intrinsic defect in their ability to perform cytolysis and respond to IFN-alpha. Furthermore, a single bout of maximal exercise increases NKCC and CD56+ cell number similarly in both young and old subjects regardless of the target cell used.

Exercise suppresses macrophage antigen presentation.

This study determined the effects of exercise on the ability of macrophages (Mphi) to present antigen to T cells. Pathogen-free male Balb/c mice (8 +/- 2 wk of age) were randomly assigned to either home cage control, moderate exercise (Mod; 18 m/min, 5% grade, 0.5 h/day), exhaustive exercise (Exh, 18-30 m/min, 3 h/day), or treadmill control groups. The mice underwent treatments for 4 days during peritoneal thioglycolate inflammation. Peritoneal Mphi were harvested, purified, and incubated with chicken ovalbumin (C-OVA; 0-10 mg/ml) for 18 h. Mphi were then cocultured with C-OVA-specific T cells for 48 h, and the supernatants were analyzed via ELISA for interleukin-2 as an indication of Mphi antigen presentation (AP). Exh exhibited suppressed ( approximately 25-34%) Mphi AP across a wide range of C-OVA doses when measured immediately, 3, and 24 h postexercise. In contrast, Mod had reduced Mphi AP only at 3 h postexercise. Mphi AP was also lower in the treadmill control (4-27%) compared with the home cage control group, but was significantly higher than Exh. The reduction in Mphi AP was not due to exercise-induced differences in Mphi number, percentage, or expression of intercellular adhesion molecule-1, B7-2, or major histocompatability complex II, molecules important in AP. In conclusion, our data lend evidence that may help explain the increased incidence of infection observed after prolonged exhaustive exercise or overtraining.

Intracellular mechanisms responsible for exercise-induced suppression of macrophage antigen presentation.

In a previous study, we demonstrated that exhaustive exercise suppressed peritoneal macrophage antigen presentation (AP). In this study, we explored the intracellular mechanism(s) responsible for this suppression. Pathogen-free male BALB/c mice (8 +/- 2 wk) were randomly assigned to either home cage control (HCC) or exhaustive exercise stress (Exh, 18-30 m/min for 3 h/day) treatment groups. The mice underwent treatments for a period of 4 days during induced peritoneal thioglycollate inflammation. Elicited macrophages were harvested, purified, and incubated with chicken ovalbumin (C-Ova, 2. 5 and 10 mg/ml) for 18 h. After macrophages were washed, they were cocultured with C-Ova-specific T cells for 48 h at which time the supernates were harvested and analyzed via ELISA for interleukin (IL)-2 as an indication of macrophage AP. There was no significant (P > 0.05) difference in macrophage AP between cells fixed with paraformaldehyde vs. those that remained unfixed, suggesting that Exh did not affect production of soluble factors influencing macrophage AP (i.e., IL-1, IL-4, PGE(2)). The ability of macrophages to generate C-Ova immunogenic peptides was analyzed using FITC-labeled C-Ova, which shows fluorescence only when degraded intracellularly. There was a significant ( approximately 20%, P < 0. 05) suppression in fluorescence in the Exh compared with HCC, indicating a possible defect in the ability of macrophages from Exh to degrade C-Ova into immunogenic peptides. Macrophages were also incubated with C-Ova immunogenic peptide in a manner identical to that for native C-Ova. We found a similar suppression ( approximately 22-38%, P < 0.05) in macrophage AP using a C-Ova peptide when compared with native C-Ova in the Exh group, indicating reduced major histocompatibility complex (MHC) II loading and/or C-Ova-MHC II complex cell surface expression. In conclusion, these data indicate an intracellular defect in the macrophage antigen processing pathway induced by Exh.

Exercise increases inflammatory macrophage antitumor cytotoxicity.

This study determined the effects of exercise on the ability of inflammatory macrophages to inhibit tumor cell growth in vitro (macrophage cytotoxicity). Thioglycollate injection (1 ml ip) was used as an inflammatory challenge and to partially activate macrophages for cytotoxicity. Inbred male C3H/HeN mice (n = 180) exercised moderately (MOD, 18 m/min, 30 min/day, 5% grade) or to exhaustion (EXH, 18-35 m/min, 2-4 h, 5% grade) on a motor-driven treadmill for 3 consecutive days after injection. Control (CON) mice were kept in stimulated treadmill lanes directly over the runners. Mice were killed immediately or 3 or 8 h postexercise. Macrophages from both MOD and EXH exercise groups manifested significantly (P < 0.05) enhanced (approximately 50%) cytotoxicity compared with those from CON group at all time points postexercise. This potentially beneficial exercise effect was not related to macrophage production of interleukin-1 beta, reactive nitrogen or oxygen intermediates, or number of macrophages in the assay but may have been manifested, in part, by tumor necrosis factor-alpha. Plasma corticosterone was significantly elevated immediately postexercise in MOD and EXH compared with CON mice; however, no evidence existed for an immuno-suppressive effect of corticosterone on macrophage cytotoxicity, perhaps because of insensitivity of inflammatory macrophages to glucocorticoid suppression seen in vitro. These data only partially support the "inverted U hypothesis," which states that moderate exercise may enhance, whereas very heavy exercise or a lack of exercise may attenuate, the immune response. Further study is needed to determine the physiological significance of these findings and the effects of exercise on macrophage subsets sensitive to glucocorticoid suppression (i.e., fully activated macrophages).

Effects of exercise on macrophage activation for antitumor cytotoxicity.

Recent evidence suggests that exercise affects macrophage functions and that amount of exercise may be important. We determined effects of moderate (MOD) and exhaustive treadmill running (EXH) on 1) ability of macrophages to become activated for antitumor cytotoxicity after injection of heat-inactivated Propionibacterium acnes in vivo, 2) macrophage responsiveness to activating agents lipopolysaccharide and interferon-gamma, and 3) role of glucocorticoids and various macrophage metabolic products in modulating cytotoxicity in exercised animals. Male C3H/HeN mice were randomly assigned to MOD (18 m/min, 5% grade, 30 min/day) or EXH (18-35 m/min, 5%, 2-4 h) on a motor-driven treadmill. Control animals were kept in simulated treadmill lanes located directly over the runners. In general, both MOD and EXH increased cytotoxicity (42 and 22%, respectively, across all experiments; P < 0.05). Enhanced cytotoxicity was not due to altered macrophage adherence, tumor necrosis factor-alpha, interleukin-1 beta, or reactive oxygen species. Reactive nitrogen species were responsible for enhanced toxicity in EXH only. Macrophage cytotoxicity was further increased by lipopolysaccharide and interferon-gamma to a similar maximal level that was the same in all groups. Plasma corticosterone was elevated two- and fourfold in MOD and EXH, respectively, but there was no correlation between plasma corticosterone and macrophage cytotoxicity when compared across all groups even though cells were sensitive to steroid-mediated suppression in vitro. However, consistent with a corticosterone effect, EXH reduced the number of peritoneal macrophages elicited during P. acnes inflammation and abolished the typical exercise-induced increase in cytotoxicity of activated macrophages.(ABSTRACT TRUNCATED AT 250 WORDS)