Effect of ethanol exposure on innate immune response in sepsis

Alcohol use disorder, reported by 1 in 8 critically ill patients, is a risk factor for death in sepsis patients. Sepsis, the leading cause of death, kills over 270,000 patients in the United States alone and remains without targeted therapy. Immune response in sepsis transitions from an early hyperinflammation to persistent inflammation and immunosuppression and multiple organ dysfunction during late sepsis. Innate immunity is the first line of defense against pathogen invasion. Ethanol exposure is known to impair innate and adaptive immune response and bacterial clearance in sepsis patients. Specifically, ethanol exposure is known to modulate every aspect of innate immune response with and without sepsis. Multiple molecular mechanisms are implicated in causing dysregulated immune response in ethanol exposure with sepsis, but targeted treatments have remained elusive. In this article, we outline the effects of ethanol exposure on various innate immune cell types in general and during sepsis.

Markers of Neuroinflammation in the Serum of Prepubertal Children with Fetal Alcohol Spectrum Disorders

BACKGROUND

Fetal Alcohol Spectrum Disorders (FASD) are the manifestation of the damage caused by alcohol consumption during pregnancy. Children with Fetal Alcohol Syndrome (FAS), the extreme FASD manifestation, show both facial dysmorphology and mental retardation. Alcohol consumed during gestational age prejudices brain development by reducing, among others, the synthesis and release of neurotrophic factors and neuroinflammatory markers. Alcohol drinking also induces oxidative stress.

HYPOTHESIS/OBJECTIVE

The present study aimed to investigate the potential association between neurotrophins, neuroinflammation, and oxidative stress in 12 prepubertal male and female FASD children diagnosed as FAS or partial FAS (pFAS).

METHODS

Accordingly, we analyzed, in the serum, the level of BDNF and NGF and the oxidative stress, as Free Oxygen Radicals Test (FORT) and Free Oxygen Radicals Defense (FORD). Moreover, serum levels of inflammatory mediators (IL-1α, IL-2, IL-6, IL-10, IL-12, MCP-1, TGF-β, and TNF-α) involved in neuroinflammatory and oxidative processes have been investigated.

RESULTS

We demonstrated low serum levels of NGF and BDNF in pre-pubertal FASD children with respect to healthy controls. These changes were associated with higher serum presence of TNF- α and IL-1α. Quite interestingly, an elevation in the FORD was also found despite normal FORT levels. Moreover, we found a potentiation of IL-1α, IL-2, IL-10, and IL-1α1 in the analyzed female compared to male children.

CONCLUSION

The present investigation shows an imbalance in the peripheral neuroimmune pathways that could be used in children as early biomarkers of the deficits observed in FASD.

Alcohol use disorder and circulating cytokines: A systematic review and meta-analysis

There has been emerging interest in the role of the immune system in the pathophysiology of alcohol use disorder (AUD) given alcohol consumption stimulates immune cells to secrete peripheral pro- and anti-inflammatory cytokines. We conducted a systematic review and meta-analysis to determine whether an abnormal inflammatory cytokine profile exists in AUD patients compared to controls and whether cytokine levels were correlated with behavioural and psychiatric variables. Using the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-analyses) guidelines, a comprehensive search of electronic databases (MEDLINE, EMBASE, Web of Science Core Collection and the Cochrane Library) was conducted, for AUD-related terms in combination with cytokine-related terms. Patients had to meet established criteria for AUD and be compared with healthy controls. A critical appraisal was completed using the Newcastle-Ottawa Scale. Twenty-four papers met the inclusionary criteria with 46 serum or plasma cytokines measured without immune stimulation whereby 17 studies had sufficient data for inclusion in the meta-analysis. Collectively, AUD patients had greater cytokine concentrations than control patients g = 0.85 [ 95% CI 0.42, 1.29]. Differences in cytokine concentrations between AUD patients and controls varied within-study by stage of illness (R₍₂₎² = 19.56%). The greatest differences were reported when AUD patients were engaging in active drinking g = 0.96 [0.49, 1.43] or were in alcohol withdrawal g = 1.25 [0.71, 1.80]. Baseline findings were moderated within and between studies by cytokine identity R₍₂₎² = 51.10%; R₍₃₎² = 44.89%. Cytokine concentrations were not significantly correlated with self-reported craving for alcohol, but were with alcohol consumption r = 0.22 [-0.05, 0.46]. The relationship between cytokine concentration and consumption was moderated by cytokine identity (R₍₂₎² = 100.00%; R₍₃₎² = 100.00%), and sample age (R₍₂₎² = 0.00%; R₍₃₎² = 95.76%). There is sufficient evidence to support the presence of an abnormal circulating cytokine profile in AUD which may vary with respect to the different stages of AUD illness.

Recent Insights Into the Role of Immune Cells in Alcoholic Liver Disease

Accumulating clinical and experimental evidences have demonstrated that both innate and adaptive immunity are involved in the pathogenesis of alcoholic liver disease (ALD), in which the role of immunity is to fuel the inflammation and to drive the progression of ALD. Various immune cells are implicated in the pathogenesis of ALD. The activation of innate immune cells induced by alcohol and adaptive immune response triggered by oxidative modification of hepatic constituents facilitate the persistent hepatic inflammation. Meanwhile, the suppressed antigen-presenting capability of various innate immune cells and impaired function of T cells may consequently lead to an increased risk of infection in the patients with advanced ALD. In this review, we summarized the significant recent findings of immune cells participating in ALD. The pathways and molecules involved in the regulation of specific immune cells, and novel mediators protecting the liver from alcoholic injury via affecting these cells are particularly highlighted. This review aims to update the knowledge about immunity in the pathogenesis of ALD, which may facilitate to enhancement of currently available interventions for ALD treatment.

Mast Cells and Arachidonic Acid Cascade in Inflammation

Prostaglandin D2 PGD2 is a major cyclooxygenase metabolite of arachidonic acid produced by mast cells and it is released following allergen challenge in diseases, such as allergic diseases. PGD2 may act as a neuromodulator and as an allergic and inflammatory mediator. In allergic diseases, activated mast cell synthesizes prostaglandin D2 (first cyclo-oxygenate mediator) which has bronchoconstrictive and vasodilating effects and attracts several leukocytes. It has been found that activated mast cells, challenged with physiological and non- physiological secretagogues, release elevated histamine and tryptase and chymase, leukotrienes B4, C4 and D4, 5-hydroxyeicosatetraenoic acid, PGD2, Platelet Activating Factor (PAF), heparin, and high-molecular-weight neutrophil chemotactic factor and cytokines/chemokines. PGD2 exerts its biological activity through the DP and CRTH2 receptors and their cDNA cloning which were characterized 15 years ago. In this report, we revisited the biological effects of arachidonic acid compounds released by activated mast cells in allergic and inflammatory states.

Alteration in the concentrations of Interleukin-7 (IL-7), Interleukin-10 (IL-10) and Granulocyte Colony Stimulating Factor (G-CSF) in alcohol-dependent individuals without liver disease, during detoxification therapy

BACKGROUND

The course of Interleukin-7 (IL-7), Interleukin-10 (IL-10) and Granulocyte Colony Stimulating Factor (G-CSF) was investigated in alcohol-dependent individuals without liver disease in order to ascertain the use of these cytokines as markers for the follow-up testing and the outcome of the detoxification treatment.

METHODS

Forty-eight alcohol-dependent individuals were admitted for alcohol detoxification. Blood was obtained upon admission, two weeks later and after the completion of the detoxification period (4-5 weeks). Serum IL-7, IL-10 and G-CSF were measured with a commercially available sandwich enzyme immunoassay.

RESULTS

IL-7 concentration was steadily high from admission up to two weeks later and then showed a fall, yet still remaining significantly higher than in the control group at the end of the detoxification treatment. IL-10 concentration was significantly low on admission, presenting a linear increase during therapy and remained insignificantly low at the end. G-CSF was significantly elevated on admission and presented a linear fall ending up in almost normal values at the end of the detoxification therapy.

CONCLUSIONS

The alterations in the concentration of IL-7, IL-10 and G-CSF and their trend to normalization during the detoxification therapy are indicative of the generalized immune system disorder, caused by alcohol abuse. Further studies will help in further elucidating the pathophysiology of the immune system function in alcohol abuse, while immunological parameters might serve as biological markers and diagnostic tools for the assessment of the course and the outcome of the detoxification therapy.

Chronic ethanol exposure selectively inhibits the influenza-specific CD8 T cell response during influenza a virus infection

BACKGROUND

It is well established that chronic ethanol (EtOH) consumption is associated with increased incidence and disease severity of respiratory infections. Our recent work demonstrates this increase in disease severity to influenza A virus (IAV) infections is due, in part, to a failure to mount a robust IAV-specific CD8 T cell response along with a specific impairment in the ability of these T cells to produce interferon γ (IFNγ). However, the full extent of the lesion in the effector CD8 T cell compartment during chronic EtOH consumption remains unknown.

METHODS

Utilizing the Meadows-Cook murine model of chronic alcohol consumption, mice received EtOH in their drinking water for 8 or 12 weeks. Mice were challenged intranasally with IAV, and the activation and effector functions of IAV-specific CD8 T cells were determined in both the lung-draining lymph nodes (dLN) and lungs.

RESULTS

Our results confirm the defect in IFNγ production; however, the ability of IAV-specific T cells to produce tumor necrosis factor α (TNFα) and interleukin-2 (IL-2) in EtOH-consuming mice remains unaltered. In contrast, EtOH consumption significantly reduces the ability of CD8 T cells to degranulate and kill IAV-specific targets. Finally, our findings suggest the lesion begins during the initial activation of CD8 T cells, as we observe early defects in proliferation in the dLN of IAV-infected, EtOH-consuming mice.

CONCLUSIONS

These findings highlight the previously unrecognized depth of the lesion in the IAV-specific CD8 T cell response during chronic EtOH consumption. Given the important role CD8 T cell immunity plays in control of IAV, these findings may aid in the development of vaccination and/or therapeutic strategies to reverse these defects in the CD8 T cell response and reduce serious disease outcomes associated with IAV infections in alcoholics.

Peripheral blood dendritic cells in alcoholic and autoimmune liver disorders

Little is known about effects of alcohol consumption on dendritic cell (DC) function and resultant immune response. However, quantitative and qualitative disturbances of DCs are speculated to be involved in alcohol-related as well as in other liver pathology. The present study aimed to evaluate changes in circulating DC subsets in alcoholic liver disease (N = 43), autoimmune hepatitis (N = 26) and primary biliary cirrhosis (N = 20). DCs isolated from the peripheral blood of recruited participants were stained with monoclonal antibodies against blood dendritic cell antigens (BDCAs) and estimated using the flow cytometry. Myeloid DCs were defined as BDCA-1(+)/CD19(-) cells, and lymphoid DCs as BDCA-2(+)/CD123(+) cells. Total numbers of circulating DCs in subjects with some liver diseases were markedly lower than in the healthy participants (p = 0.03). There was a significantly lower percentage of circulating BDCA-2(+)/CD123(+) (p = 0.02), and a tendency for the percentage of circulating BDCA-1(+)/CD19(-) cells to decrease in patients with liver diseases compared to the controls (p = 0.09). These results may suggest that decreased numbers of DCs may be responsible for reduced adaptive immune responses and increased susceptibility to infections and cancer development observed in patients exposed to alcohol. Moreover, numerical abnormalities of DCs may contribute to the breakdown of self-tolerance, a feature of autoimmune diseases.

Implications of ER stress, the unfolded protein response, and pro- and anti-apoptotic protein fingerprints in human monocyte-derived dendritic cells treated with alcohol

BACKGROUND

Dendritic cells (DCs) are responsible for the activation of T cells and B cells. There is accumulating evidence that psychoactive substances such as alcohol can affect immune responses. We hypothesize that this occurs by modulating changes in proteins triggering a process known as unfolded protein response (UPR). This process protects cells from the toxic effects of misfolded proteins responsible for causing endoplasmic reticulum (ER) stress. Although much is known about ER stress, little is understood about the consequences of ethanol use on DC's protein expression.

METHODS

In this study, we investigated alterations in the proteins of human monocyte-derived dendritic cells (MDDC) treated with 0.1% of alcohol by two-dimensional (2D) gel electrophoresis followed by liquid chromatography-tandem mass spectrometry, protein identification, and confirmation at the gene expression level by qRT-PCR.

RESULTS

Proteomes of related samples demonstrated 32 differentially expressed proteins that had a 2-fold or greater change in expression (18 spots were up-regulated and 14 were down-regulated), compared to the control cultures (untreated cells). Alcohol significantly changed the expression of several components of the UPR stress-induced pathways that include chaperones, ER stress, antioxidant enzymes, proteases, alcohol dehydrogenase, cytoskeletal and apoptosis-regulating proteins. qRT-PCR analyses highlighted the enhanced expression of UPR and antioxidant genes that increased (18 hours) with alcohol treatment.

CONCLUSION

Results of these analyses provide insights into alcohol mechanisms of regulating DC and suggest that alcohol induced specifically the UPR in DC. We speculate that activation of a UPR by alcohol may protect the DC from oxidant injury but may lead to the development of alcohol-related diseases.

Short-term administration of ethanol in mice deviates antigen presentation activity towards B cells

Alcohol has a variety of short- and long-term effects on cell-mediated and humoral immune response. Herein, we have characterized the impact of high-dose EtOH administration on phenotypic and functional features of murine APC subsets, including dendritic cell (DC), macrophages and B cells. Impaired cytokine synthesis and Leishmania-phagocytosis was observed in peritoneal macrophages following EtOH administration. Moreover, EtOH exposure led to decreased levels of splenic myeloid DC and increased percentage of macrophages with no changes in splenic lymphoid DC and B cells. Adverse effects of short-term EtOH administration also resulted in impaired OVA-endocytosis by DC and macrophages. In contrast, EtOH consumption upregulates OVA-internalization by B cells. These changes on APC hierarchy may play a role shifting the fate of the immune response after EtOH ingestion. In addition to an overall downregulation of Toll-like receptor-TLR-4 expression by splenic APC, a downregulation of TLR-2 expression in macrophages was observed. Moreover, EtOH exposure altered the expression of co-signalling molecules on splenic APC, downregulating CD40 on macrophages and upregulating CD80 on B cells, with no impact on DC subsets. The net result of changes in TLR-mediated and co-stimulatory signals may determine the altered immunological status induced by acute consumption of alcohol. A direct impact of high-dose EtOH administration in the activation status of splenic CD4(+) T cells was observed. Together, our results demonstrated that short-term high-dose EtOH administration has differential impact on APC populations, downregulating splenic macrophages and DC activity but up-regulating B lymphocyte function as APC, and ultimately yielding a micro-environment that led to increased activation of CD4(+) T cells.

Impact of IL-32 on Histamine Release by Human Derived Umbilical Cord Blood Mast Cells

IL-32 is onae of the last important cytokines discovered, produced mainly by T cells, natural killer cells, and epithelial cells. Probably many other different cells are a source of IL-32, which has been found to be a powerful pro-inflammatory mediator. Here we studied the effect of IL-32 on histamine release by human-derived cord-blood mast cells. In these studies we found that IL-32 significantly stimulates the release of histamine only at high concentrations (100 ng/ml) while at 10 or 50 ng/ml it had no effect. These results were found for the first time and demonstrate that IL-32 may play an important role in allergic and inflammatory diseases.