Adrenergic regulation of the vasculature impairs leukocyte interstitial migration and suppresses immune responses.

The sympathetic nervous system (SNS) controls various physiological functions via the neurotransmitter noradrenaline. Activation of the SNS in response to psychological or physical stress is frequently associated with weakened immunity. Here, we investigated how adrenoceptor signaling influences leukocyte behavior. Intravital two-photon imaging after injection of noradrenaline revealed transient inhibition of CD8+ and CD4+ T cell locomotion in tissues. Expression of ß-adrenergic receptor in hematopoietic cells was not required for NA-mediated inhibition of motility. Rather, chemogenetic activation of the SNS or treatment with adrenergic receptor agonists induced vasoconstriction and decreased local blood flow, resulting in abrupt hypoxia that triggered rapid calcium signaling in leukocytes and halted cell motility. Oxygen supplementation reversed these effects. Treatment with adrenergic receptor agonists impaired T cell responses induced in response to viral and parasitic infections, as well as anti-tumor responses. Thus, stimulation of the SNS impairs leukocyte mobility, providing a mechanistic understanding of the link between adrenergic receptors and compromised immunity.

The IgG3 subclass of ß1-adrenergic receptor autoantibodies is an endogenous biaser of ß1AR signaling.

Dysregulation of immune responses has been linked to the generation of immunoglobulin G (IgG) autoantibodies that target human ß1ARs and contribute to deleterious cardiac outcomes. Given the benefits of ß-blockers observed in patients harboring the IgG3 subclass of autoantibodies, we investigated the role of these autoantibodies in human ß1AR function. Serum and purified IgG3(+) autoantibodies from patients with onset of cardiomyopathy were tested using human embryonic kidney (HEK) 293 cells expressing human ß1ARs. Unexpectedly, pretreatment of cells with IgG3(+) serum or purified IgG3(+) autoantibodies impaired dobutamine-mediated adenylate cyclase (AC) activity and cyclic adenosine monophosphate (cAMP) generation while enhancing biased ß-arrestin recruitment and Extracellular Regulated Kinase (ERK) activation. In contrast, the ß-blocker metoprolol increased AC activity and cAMP in the presence of IgG3(+) serum or IgG3(+) autoantibodies. Because IgG3(+) autoantibodies are specific to human ß1ARs, non-failing human hearts were used as an endogenous system to determine their ability to bias ß1AR signaling. Consistently, metoprolol increased AC activity, reflecting the ability of the IgG3(+) autoantibodies to bias ß-blocker toward G-protein coupling. Importantly, IgG3(+) autoantibodies are specific toward ß1AR as they did not alter ß2AR signaling. Thus, IgG3(+) autoantibody biases ß-blocker toward G-protein coupling while impairing agonist-mediated G-protein activation but promoting G-protein-independent ERK activation. This phenomenon may underlie the beneficial outcomes observed in patients harboring IgG3(+) ß1AR autoantibodies.

Sympathetic nervous tone limits the development of myeloid-derived suppressor cells.

Sympathetic nerves that innervate lymphoid organs regulate immune development and function by releasing norepinephrine that is sensed by immune cells via their expression of adrenergic receptors. Here, we demonstrate that ablation of sympathetic nervous system (SNS) signaling suppresses tumor immunity, and we dissect the mechanism of such immune suppression. We report that disruption of the SNS in mice removes a critical α-adrenergic signal required for maturation of myeloid cells in normal and tumor-bearing mice. In tumor-bearing mice, disruption of the α-adrenergic signal leads to the accumulation of immature myeloid-derived suppressor cells (MDSCs) that suppress tumor immunity and promote tumor growth. Furthermore, we show that these SNS-responsive MDSCs drive expansion of regulatory T cells via secretion of the alarmin heterodimer S100A8/A9, thereby compounding their immunosuppressive activity. Our results describe a regulatory framework in which sympathetic tone controls the development of innate and adaptive immune cells and influences their activity in health and disease.

Altered Structural Brain Networks Related to Adrenergic/Muscarinic Receptor Autoantibodies in Chronic Fatigue Syndrome.

BACKGROUND AND PURPOSE: Recent studies suggest that the autoantibodies against adrenergic/muscarinic receptors might be one of the causes and potential markers of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). The purpose of this study was to investigate the structural network changes related to autoantibody titers against adrenergic/muscarinic receptors in ME/CFS by performing a single-subject gray matter similarity-based structural network analysis. METHODS: We prospectively examined 89 consecutive right-handed ME/CFS patients who underwent both brain MRI including 3D T1-wighted images and a blood analysis of autoantibodies titers against ß1 adrenergic receptor (ß1 AdR-Ab), ß2 AdR-Ab, M3 acetylcholine receptor (M3 AchR-Ab), and M4 AchR-Ab. Single-subject gray matter similarity-based structural networks were extracted from segmented gray matter images for each patient. We calculated local network properties (betweenness centrality, clustering coefficient, and characteristic path length) and global network properties (normalized path length λ, normalized clustering coefficient γ, and small-world network value δ). We investigated the correlations between the autoantibody titers and regional gray matter/white matter volumes, the local network properties, and the global network properties. RESULTS: Betweenness centrality showed a significant positive correlation with ß1-AdR-Ab in the right dorsolateral prefrontal cortex. The characteristic path length showed a significant negative correlation with ß2-AdR-Ab in the right precentral gyrus. There were no significant correlations between the antibody titers and the regional gray matter/white matter volumes, and the global network properties. CONCLUSIONS: Our findings suggest that ß1 AdR-Ab and ß2 AdR-Ab are potential markers of ME/CFS.

Apical splenic nerve electrical stimulation discloses an anti-inflammatory pathway relying on adrenergic and nicotinic receptors in myeloid cells.

The autonomic nervous system innervates all lymphoid tissues including the spleen therefore providing a link between the central nervous system and the immune system. The only known mechanism of neural inhibition of inflammation in the spleen relies on the production of norepinephrine by splenic catecholaminergic fibers which binds to ß2-adrenergic receptors (ß 2-ARs) of CD4+ T cells. These CD4+ T cells trigger the release of acetylcholine that inhibits the secretion of inflammatory cytokines by macrophages through α7 nicotinic acetylcholine receptor (α7nAchRs) signaling. While the vagal anti-inflammatory pathway has been extensively studied in rodents, it remains to be determined whether it coexists with other neural pathways. Here, we have found that three nerve branches project to the spleen in mice. While two of these nerves are associated with an artery and contain catecholaminergic fibers, the third is located at the apex of the spleen and contain both catecholaminergic and cholinergic fibers. We found that electrical stimulation of the apical nerve, but not the arterial nerves, inhibited inflammation independently of lymphocytes. In striking contrast to the anti-inflammatory pathway mechanism described so far, we also found that the inhibition of inflammation by apical nerve electrical stimulation relied on signaling by both ß 2-ARs and α7nAchRs in myeloid cells, with these two signaling pathways acting in parallel. Most importantly, apical splenic nerve electrical stimulation mitigated clinical symptoms in a mouse model of rheumatoid arthritis further providing the proof-of-concept that such an approach could be beneficial in patients with Immune-mediated inflammatory diseases.

No evidence for humoral autoimmunity against cardiomyocytes, adrenergic or muscarinic receptors in patients with Tako-Tsubo cardiomyopathy.

BACKGROUND: An association between Tako-Tsubo cardiomyopathy (TTC) and underlying malignancies has been observed, suggesting that TTC might be the consequence of paraneoplastic phenomena. This study investigates the presence of autoantibodies against cardiomyocytes as well as adrenergic (ß1, ß2) and muscarinic (M2) receptors in patients with TTC. METHODS AND RESULTS: Serum from 20 TTC patients and 20 controls with ischemic heart disease was obtained. Indirect immunofluorescence testing for intracellular autoantibodies against cardiomyocytes showed a homogenous distribution, as in both groups 9 of 20 sera displayed a characteristic binding pattern of antibodies including vascular walls and intracellular structures. Flow cytometry analysis revealed no difference between TTC and controls in the binding of autoantibodies to the surface antigens of cardiomyocyte HL-1 cells (p = 0.569, t-test). Flow cytometry analysis of nontransfected wild type cells (p = 0.633, t-test), M2 receptor-transfected cells (p = 0.687, t-test), ß1 receptor-transfected cells (p = 0.444, t-test) and ß2 receptor-transfected cells (p = 0.632, t-test) showed similar results for control and TTC sera. Likewise, the binding pattern of TTC patients with a history of neoplasia compared to those without or to controls did not differ significantly (p > 0.05, u-test). CONCLUSION: Findings suggest that the presumed paraneoplastic etiology of TTC cannot be attributed to the formation of these antibodies.

Increased circulating ß2-adrenergic receptor autoantibodies are associated with smoking-related emphysema.

Smoking is a dominant risk factor for chronic obstructive pulmonary disease (COPD) and emphysema, but not every smoker develops emphysema. Immune responses in smokers vary. Some autoantibodies have been shown to contribute to the development of emphysema in smokers. ß2-adrenergic receptors (ß2-ARs) are important targets in COPD therapy. ß2-adrenergic receptor autoantibodies (ß2-AAbs), which may directly affect ß2-ARs, were shown to be increased in rats with passive-smoking-induced emphysema in our current preliminary studies. Using cigarette-smoke exposure (CS-exposure) and active-immune (via injections of ß2-AR second extracellular loop peptides) rat models, we found that CS-exposed rats showed higher serum ß2-AAb levels than control rats before alveolar airspaces became enlarged. Active-immune rats showed increased serum ß2-AAb levels, and exhibited alveolar airspace destruction. CS-exposed-active-immune treated rats showed more extensive alveolar airspace destruction than rats undergoing CS-exposure alone. In our current clinical studies, we showed that plasma ß2-AAb levels were positively correlated with the RV/TLC (residual volume/total lung capacity) ratio (r = 0.455, p < 0.001) and RV%pred (residual volume/residual volume predicted percentage, r = 0.454, p < 0.001) in 50 smokers; smokers with higher plasma ß2-AAb levels exhibited worse alveolar airspace destruction. We suggest that increased circulating ß2-AAbs are associated with smoking-related emphysema.

[Autoimmunity and Prognosis of Patients With Morphologically Documented Myocarditis].

AIM: to assess clinical and prognostic value of circulating cardiospecific autoantibodies (AAB) and CD4+ T-regulatory cells in patients with myocarditis. MATERIAL AND METHODS: We included into this study 47 patients with lymphocytic myocarditis verified by analysis of histological and immunohistochemical data. Comparison group consisted of 30 practically healthy persons. Content of marker cardiotropic AAT were measured with the help of standardized immune enzyme test-systems. Number of circulating CD4+CD25+ and CD4+CD25+FoxP3+ T-lymphocytes were evaluated by flow cytometry. RESULTS: Among factors determining prognosis of patients with lymphocytic myocarditis factors of key significance were the presence of clinically overt heart failure at the disease debut, and degree of reduction of left ventricular ejection fraction. Distinctive feature of active myocarditis was elevation of titer of AABs to sarcomeric, cytoskeleton, and cytoplasmic proteins of cardiomyocytes, as well as elevated level of AABs to various epitopes of adenine nucleotide translocator. Elevated level of AAB to 1-adrenoreceptors was an independent predictor of unfavorable outcome in patients with lymphocytic myocarditis. Increased population of circulating CD4+CD25+ T-regulatory cells was as sociated with elevated concentration of of natriuretic peptide. CONCLUSION: Abnormalities in the system of autoimmunity play key role not only in pathogenesis but also in prognosis of inflammatory myocardial diseases. Changes of profile of circulating cardiospecific AABs and T-regulatory cells can bear a protective function.

Importance of adrenergic pathways in women's cancers.

The importance of adrenergic pathways in cancer has long been suspected, but now there is mounting epidemiological, preclinical, and clinical evidence of its importance in gynecologic cancers. To date, most of these effects are mediated primarily through the beta 2 adrenergic receptor activation of the tumor cell cyclic AMP-protein kinase A signaling pathway. This review will discuss the current knowledge about the neuroendocrine stress response in gynecologic tumor biology.

Differential TNF production by monocyte subsets under physical stress: blunted mobilization of proinflammatory monocytes in prehypertensive individuals.

Elevated blood pressure (BP) and infiltration of the vasculature by monocytes contribute to vascular pathology; but, monocyte migratory characteristics based on differing inflammatory potential under adrenergic activation remains unclear. We compared nonclassical (CD14(+)CD16(++); HLA-DR(+)), intermediate (CD14(++)CD16(+); HLA-DR(++)), and classical (CD14(++)CD16(-); HLA-DR(+/-)) monocyte trafficking and their LPS-stimulated TNF production in response to a physical stressor (20-min treadmill exercise at 65-70% VO(2peak)) in participants with high prehypertension (PHT), mild PHT or normal BP (NBP). To determine adrenergic receptor (AR) sensitivity, pre-exercise cells were also treated with isoproterenol (Iso). When cells were stimulated with LPS, the CD16 molecules were downregulated, and monocyte subsets were differentiated based on HLA-DR expression. Monocyte subpopulations (as % of total monocytes) and intracellular TNF production were evaluated by flow cytometry. TNF production in all subsets decreased post-exercise and with ex-vivo incubation with Iso, irrespective of BP (p<0.001), with nonclassical and intermediate monocytes being a major source of TNF production. Overall, % nonclassical monocytes increased, % intermediate did not change, whereas % classical decreased post-exercise (p<0.001). However, % increase in nonclassical monocytes under exercise-induced adrenergic activation was blunted in high PHT individuals (p<0.05), but not in individuals with mild PHT and NBP. These findings extend our previous reports by showing that the mobilization of proinflammatory monocytes under physical stress is attenuated with even mild BP elevation. This may be indicative of monocytic AR desensitization and/or greater adhesion of "proinflammatory" monocytes to the vascular endothelium in hypertension with potential clinical implications of vascular pathology.

Neuroendocrine-immune interactions and responses to exercise.

This article reviews the interaction between the neuroendocrine and immune systems in response to exercise stress, considering gender differences. The body's response to exercise stress is a system-wide effort coordinated by the integration between the immune and the neuroendocrine systems. Although considered distinct systems, increasing evidence supports the close communication between them. Like any stressor, the body's response to exercise triggers a systematic series of neuroendocrine and immune events directed at bringing the system back to a state of homeostasis. Physical exercise presents a unique physiological stress where the neuroendocrine and immune systems contribute to accommodating the increase in physiological demands. These systems of the body also adapt to chronic overload, or exercise training. Such adaptations alleviate the magnitude of subsequent stress or minimize the exercise challenge to within homeostatic limits. This adaptive capacity of collaborating systems resembles the acquired, or adaptive, branch of the immune system, characterized by the memory capacity of the cells involved. Specific to the adaptive immune response, once a specific antigen is encountered, memory cells, or lymphocytes, mount a response that reduces the magnitude of the immune response to subsequent encounters of the same stress. In each case, the endocrine response to physical exercise and the adaptive branch of the immune system share the ability to adapt to a stressful encounter. Moreover, each of these systemic responses to stress is influenced by gender. In both the neuroendocrine responses to exercise and the adaptive (B lymphocyte) immune response, gender differences have been attributed to the 'protective' effects of estrogens. Thus, this review will create a paradigm to explain the neuroendocrine communication with leukocytes during exercise by reviewing (i) endocrine and immune interactions; (ii) endocrine and immune systems response to physiological stress; and (iii) gender differences (and the role of estrogen) in both endocrine response to physiological stress and adaptive immune response.

Immunoexpression of adrenergic receptors in detrusor from patients with prune belly syndrome: a digital quantification.

INTRODUCTION: Prune belly syndrome (PBS) presents with large-capacity bladders, high compliance and post-void residual volumes. Operative and conservative treatments are controversial. When histologically compared to normal bladder, bladder outlet obstruction results in an up- or down-regulation of adrenoceptors. Our goal was to study the immunoexpression of adrenoceptors in detrusor from patients with PBS. MATERIALS AND METHODS: Bladder domes from PBS patients (n=14) were studied (PBG). For normal controls, bladder specimens were obtained at adult surgery (n=13) (CG1) and at child autopsy (n=5) (CG2). Staining was performed using antibodies to alpha1a, alpha1b, alpha1d and beta3 adrenoceptors. Five to 10 images were captured on an optic microscope with a digital camera and analysed with Photoshop. The immunocyhistochemical index with arbitrary units was calculated and compared. RESULTS: Mean age was 1.28, 64 and 1.41 years for PBG, CG1 and CG2, respectively. The immunohistochemical index with arbitrary units of alpha1a receptors was 0.06 in PBG, 0.16 in CG1 and 0.14 in CG2 (p=0.008); of alpha1b 0.06, 0.06 and 0.07 (p=0.781); and of alpha1d 0.04, 0.04 and 0.05 (p=0.618). Regarding beta3 the respective values were 0.07, 0.14 and 0.10 (p=0.378). CONCLUSION: Our results show a decrease in alpha1a-adrenoceptor immunostaining intensity in detrusor from children with PBS. Further in vitro studies are needed to determine whether these observations are physiologically significant.

Clinical implications of anti-cardiac immunity in dilated cardiomyopathy.

Criteria of organ-specific autoimmunity are fulfilled in a subset of patients with myocarditis/dilated cardiomyopathy (DCM). In particular, circulating heart-reactive autoantibodies are found in such patients and symptom-free relatives. These autoantibodies are directed against multiple antigens, some of which are expressed in the heart (organ-specific), others in heart and some skeletal muscle fibres (partially heart-specific) or in heart and skeletal muscle (muscle-specific). Distinct autoantibodies have different frequency in disease and normal controls. Different techniques detect one or more antibodies, thus they cannot be used interchangeably for screening. It is unknown whether the same patients produce more antibodies or different patient groups develop autoimmunity to distinct antigens. IgG antibodies, shown to be cardiac- and disease-specific for myocarditis/DCM, can be used as autoimmune markers for relatives at risk as well as for identifying patients in whom immunosuppression may be beneficial. Some autoantibodies may also have a functional role, but further work is needed.

In vitro adrenergic modulation of cellular immune functions in experimental autoimmune encephalomyelitis.

OBJECTIVE: To analyze the effects in vitro of alpha- and beta-adrenoceptor agonists on splenocyte proliferation and on proinflammatory cytokine production in splenocytes and peritoneal macrophages (MF) in different stages of EAE. METHODS: Splenocytes and peritoneal macrophages were harvested in the acute phase of EAE and in remission, and from controls. The beta-agonist terbutaline, the alpha(1)-agonist methoxamine, and the alpha(2)-agonist UK-14304 were added with ConA or lipopolysaccharide (LPS). TNF-alpha and IFN-gamma contents in supernatant and splenocyte proliferation were determined. RESULTS: Terbutaline and UK-14304 significantly suppressed TNF-alpha production by MF. However, EAE acute phase rats were resistant to the suppressive effect of UK-14304. Terbutaline significantly suppressed IFN-gamma and TNF-alpha production by splenocytes. EAE acute phase and remission animals showed reduced terbutaline-induced inhibition of IFN-gamma production. CONCLUSIONS: Disturbed sympathetic-immune communication in EAE is characterized by alterations in adrenergic sensitivity via both alpha- and beta-adrenergic pathways.

Dilated cardiomyopathy defines serum autoantibodies against G-protein-coupled cardiovascular receptors.

In order further to identify the prevalence of anti-receptor autoantibodies in the sera of patients with dilated cardiomyopathy (DCM), we attempted to detect autoantibodies against a series of G-protein-coupled cardiovascular receptors in a well-defined population of DCM patients from Japan. Peptides corresponding to the sequences of the second extracellular loops of the human beta 1 and beta 2 adrenoceptors, alpha 1 adrenoceptors, M2 muscarinic acetylcholine receptors and angiotensin II-1 (AT1) receptors were used as antigens in an enzyme immunoassay to screen the sera from patients with DCM (n = 28). Nine sera from patients with DCM (32%) and 2 sera from healthy subjects (9%) recognized the beta 1 adrenoceptor peptide. Ten sera from patients (36%) and 3 sera from healthy subjects (13%) recognized the M2 receptor peptide. Thirty-six per cent of the patients with autoantibody against the beta 1 adrenoceptor peptide. Ten sera from patients (36%) and 3 sera from healthy subjects (13%) recognized the M2 receptor peptide. Thirty-six per cent of the patients with autoantibody against the beta 1 adrenoceptor had autoantibody against the M2 receptor. However, no significantly high frequencies of autoantibodies against the beta 2 adrenoceptor, alpha 1 adrenoceptor and AT1 receptor were found in DCM patients. Our results demonstrate that a subgroup of patients with DCM have a specific spectrum of autoantibodies which are specifically directed against the second extracellular loops of the beta 1 adrenoceptors and M2 muscarinic receptors rather than other cardiovascular receptors.

[Effect of the stimulation of lymphocyte adrenoreceptors on antitumor immunity in vitro]. / Vliianie stimuliatsii adrenoretseptorov limfotsitov na protivoopukholevyi immunitet in vitro.

It was found that the stimulating effect of alpha-adrenomimetic mesatone in the test of lymphocyte adhesion inhibition in patients with rectum cancer in vitro was eliminated by beta-adrenergic blocker phentolamine and the inhibitory effect of beta-adrenergic antagonist propranolol. It was shown in vitro that lymphocyte chemoreceptor sensitivity to the stimulating effect of mesatone decreased and sensitivity to the inhibitory effect of isadrine increased in patients with advanced stages of rectum cancer.

Atopy, autonomic function and beta-adrenergic receptor autoantibodies.

Atopic individuals (with asthma, allergic rhinitis or atopic eczema) have impaired sensitivity to beta-adrenergic agents. After the finding of antibodies to the beta-adrenergic receptor in the serum of a subject with allergic rhinitis, coded sera from atopic and control subjects were assayed for immunoglobulins that inhibited the specific binding of 125I-labelled hydroxybenzylpindolol to beta-receptors in mammalian lung membranes. Antibodies were present in nine of 60 subjects: 3/19 normal control subjects, 1/9 pre-allergic, 4/17 asthma, 0/8 allergic rhinitis, and 1/7 cystic fibrosis patients. Antibodies of the IgG class in these sera were also demonstrated by indirect precipitation of solubilized lung beta-receptors. The autonomic sensitivity of the nine antibody-positive subjects (Ab+) was compared with that of antibody-negative subjects (Ab-). The Ab+ subjects required 15.0 +/- 1.9 ng isoprenaline (isoproterenol) kg-1 min-1 i.v. to increase pulse pressure by at least 22 mmHg (Ab-, 7.7 +/- 0.4; n = 20; P less than 0.001), and 12.4 +/- 1.8 ng isoprenaline kg-1 min-1 i.v. to increase plasma cyclic AMP concentrations by 50% (Ab-, 8.08 +/- 0.62; n = 13; P less than 0.02). Ab+ subjects required 2.06 +/- 0.3% phenylephrine to dilate their pupils (Ab-, 2.55 +/- 0.08; n = 57; P less than 0.05) and 0.61 +/- 0.08% carbachol to constrict their pupils (Ab-, 0.78 +/- 0.03%; n = 57; P less than 0.05). A role for autoantibodies as beta-receptor antagonists was further supported by showing that human lung cells (VA-13 line) cultured in the presence of globulins from Ab+ subjects had a markedly impaired cyclic AMP response to isoprenaline. These results suggest that autoantibodies to beta-receptors play a pathogenetic role in asthma and related disorders. They have important implications for the concept of autoimmunity.

Autonomic abnormalities and autoantibodies to beta-adrenergic receptors.

We identified autoantibodies to beta 2-adrenergic receptors in the plasma of three apparently normal subjects, four patients with allergic asthma, one subject who was "preallergic" (at risk of allergy), and one patient with cystic fibrosis. Although these antibodies appeared to be heterogeneous, they shared the ability to affect binding of [125]protein A to calf-lung membranes, to inhibit beta-adrenergic ligand binding to calf-lung bet-adrenergic receptors, and to precipitate solubilized calf-lung beta-adrenergic receptors in an indirect immunoprecipitation assay. The presence of autoantibodies to beta-adrenergic receptors in these subjects correlates with abnormal autonomic responsiveness characterized by alpha-adrenergic and cholinergic hypersensitivity and beta-adrenergic hyposensitivity. These findings suggest that autoantibodies to beta-adrenergic receptors may play a part in the development of ment of autonomic abnormalities.