Stress, Heat Shock Proteins, and Autoimmunity: How Immune Responses to Heat Shock Proteins Are to Be Used for the Control of Chronic Inflammatory Diseases

Di (2-ethylhexyl) phthalate and polystyrene microplastics co-exposure caused oxidative stress to activate NF-κB/NLRP3 pathway aggravated pyroptosis and inflammation in mouse kidney

Polystyrene microplastic (PS-MPs) contamination has become a worldwide hotspot of concern, and its entry into organisms can cause oxidative stress resulting in multi-organ damage. The plasticizer di (2-ethylhexyl) phthalate (DEHP) is a common endocrine disruptor, these two environmental toxins often occur together, but their combined toxicity to the kidney and its mechanism of toxicity are unknown. Therefore, in this study, we established PS-MPS and/or DEHP-exposed mouse models. The results showed that alone exposure to both PS-MPs and DEHP caused inflammatory cell infiltration, cell membrane rupture, and content spillage in kidney tissues. There were also down-regulation of antioxidant enzyme levels, increased ROS content, activated of the NF-κB pathway, stimulated the levels of heat shock proteins (HSPs), pyroptosis, and inflammatory associated factors. Notably, the co-exposure group showed greater toxicity to kidney tissues, the cellular assay further validated these results. The introduction of the antioxidant n-acetylcysteine (NAC) and the NLRP3 inhibitor (MCC950) could mitigate the changes in the above measures. In summary, co-exposure of PS-MPs and DEHP induced oxidative stress that activated the NF-κB/NLRP3 pathway and aggravated kidney pyroptosis and inflammation, as well as that HSPs are also involved in this pathologic injury process. This study not only enriched the nephrotoxicity of plasticizers and microplastics, but also provided new insights into the toxicity mechanisms of multicomponent co-pollution in environmental.

Etiopathogenesis of Psoriasis: Integration of Proposed Theories

Psoriasis is a chronic inflammatory disease characterized by squamous and erythematous plaques on the skin and the involvement of the immune system. Global prevalence for psoriasis has been reported around 1-3% with a higher incidence in adults and similar proportions between men and women. The risk factors associated with psoriasis are both extrinsic and intrinsic, out of which a polygenic predisposition is a highlight out of the latter. Psoriasis etiology is not yet fully described, but several hypothesis have been proposed: 1) the autoimmunity hypothesis is based on the over-expression of antimicrobial peptides such as LL-37, the proteins ADAMTSL5, K17, and hsp27, or lipids synthesized by the PLA2G4D enzyme, all of which may serve as autoantigens to promote the differentiation of autoreactive lymphocytes T and unleash a chronic inflammatory response; 2) dysbiosis of skin microbiota hypothesis in psoriasis has gained relevance due to the observations of a loss of diversity and the participation of pathogenic bacteria such as Streptococcus spp. or Staphylococcus spp. the fungi Malassezia spp. or Candida spp. and the virus HPV, HCV, or HIV in psoriatic plaques; 3) the oxidative stress hypothesis, the most recent one, describes that the cell injury and the release of proinflammatory mediators and antimicrobial peptides that leads to activate of the Th1/Th17 axis observed in psoriasis is caused by a higher release of reactive oxygen species and the imbalance between oxidant and antioxidant mechanisms. This review aims to describe the mechanisms involved in the three hypotheses on the etiopathogeneses of psoriasis.

Bisphenol A exposure exacerbates tracheal inflammatory injury in selenium-deficient chickens by regulating the miR-155/TRAF3/ROS pathway

Bisphenol A (BPA) is an endocrine disruptor. Excessive BPA intake can damage the structure and function of the respiratory tract. Dietary selenium (Se) deficiency may also cause immune tissue damage. To investigate the potential mechanism of BPA on tracheal damage in selenium-deficient chickens and the role of microRNAs (miRNAs) in this process, we established in vitro and in vivo Se deficiency and BPA exposure models and screened out miR-155 for follow-up experiments. We further predicted and confirmed the targeting relationship between miR-155 and TRAF3 using TargetScan and dual luciferase assays and found that miR-155 was highly expressed and caused inflammatory damage. Further studies showed that BPA exposure increased airway oxidative stress, activated the NF-κB pathway, and caused inflammation and immune damage in selenium-deficient chickens, but down-regulating miR-155 and NAC treatment could reverse this phenomenon. This suggested that these pathways are regulated by the miR-155/TRAF3/ROS axis. In conclusion, BPA exposure aggravates airway inflammation in selenium-deficient chickens by regulating miR-155/TRAF3/ROS. This study revealed the mechanism of BPA exposure combined with Se deficiency in tracheal inflammatory injury in chickens and enriched the theoretical basis of BPA injury in poultry.

Hsp65-producing Lactococcus lactis inhibits experimental autoimmune encephalomyelitis by preventing cell migration into spinal cord

Multiple sclerosis is an autoimmune disease that affects the central nervous system. Because of its complexity and the difficulty to treat, searching for immunoregulatory responses that reduce the clinical signs of disease by non-aggressive mechanisms and without adverse effects is a scientific challenge. Herein we propose a protocol of oral tolerance induction that prevented and controlled MOG-induced experimental autoimmune encephalomyelitis (EAE) in C57BL/6 mice. The genetically modified strain HSP65-producing Lactococcus lactis was orally administered for 5 consecutive days either before or during disease development in mice. Both protocols of feeding HSP65 resulted in significant reduction in the clinical score of EAE. Frequencies of LAP+CD4+Foxp3- regulatory T cells were higher in spleens and inguinal lymph nodes of fed mice. In addition, intravital microscopy showed that adherence of leukocytes to venules in the spinal cord was reduced in orally treated mice. Oral treatment with HSP65-producing L.lactis prevented leukocytes to leave the secondary lymphoid organs, therefore they could not reach the central nervous system. Despite the inhibition of pathological immune response that drive EAE development, activated T cells were at normal frequencies suggesting that oral tolerance did not induce general immunosuppression, but it led to specific control of pathogenic T cells. Our results indicate a novel therapeutic strategy to prevent and control autoimmune diseases such as multiple sclerosis.

Role of Innate Immunity and Oxidative Stress in the Development of Type 1 Diabetes Mellitus. Peroxiredoxin 6 as a New Anti-Diabetic Agent

The review discusses information on the development of type 1 diabetes mellitus (T1D) as a systemic autoimmune and inflammatory disease. Focus of the review is on the role of innate immune system, including activation of some signaling cascades, cytokine response, and activity of the Toll-like receptors in the development of T1D. Dysfunction of innate immunity is the cause of the attack of pancreatic beta cells by the host T-lymphocytes, which leads to the death of pancreatic beta cells that produce insulin. Lack of insulin causes hyperglycemia and the need for lifelong injections of insulin in patients with T1D, which, nevertheless, does not exclude damage to many organs and tissues, given particular vulnerability of the blood vessels under conditions of hyperglycemia. The review discusses the role of oxidative stress as a factor that plays a major role in damage of vascular system and pancreatic tissue during the development of T1D. Considering high sensitivity of pancreatic beta cells to the action of reactive oxygen species (ROS), the possibility of using antioxidants for reducing the level of pathological consequences in the course of T1D development is discussed. New information on anti-diabetic activity of the exogenous antioxidant enzyme peroxiredoxin 6, which is capable of penetrating cells, activating insulin production in beta cells, reducing ROS levels, as well as decreasing activation of some signaling cascades, production of pro-inflammatory cytokines, and expression of Toll-like receptors in beta cells and in immune cells during T1D development is discussed.

Long-Term Overconsumption of Fat and Sugar Causes a Partially Reversible Pre-inflammatory Bowel Disease State

Nutrition appears to be an important environmental factor involved in the onset of inflammatory bowel diseases (IBD) through yet poorly understood biological mechanisms. Most studies focused on fat content in high caloric diets, while refined sugars represent up to 40% of caloric intake within industrialized countries and contribute to the growing epidemics of inflammatory diseases. Herein we aim to better understand the impact of a high-fat-high-sucrose diet on intestinal homeostasis in healthy conditions and the subsequent colitis risk. We investigated the early events and the potential reversibility of high caloric diet-induced damage in mice before experimental colitis. C57BL/6 mice were fed with a high-fat or high-fat high-sucrose or control diet before experimental colitis. In healthy mice, a high-fat high-sucrose diet induces a pre-IBD state characterized by gut microbiota dysbiosis with a total depletion of bacteria belonging to Barnesiella that is associated with subclinical endoscopic lesions. An overall down-regulation of the colonic transcriptome converged with broadly decreased immune cell populations in the mesenteric lymph nodes leading to the inability to respond to tissue injury. Such in-vivo effects on microbiome and transcriptome were partially restored when returning to normal chow. Long-term consumption of diet enriched in sucrose and fat predisposes mice to colitis. This enhanced risk is preceded by gut microbiota dysbiosis and transcriptional reprogramming of colonic genes related to IBD. Importantly, diet-induced transcriptome and microbiome disturbances are partially reversible after switching back to normal chow with persistent sequelae that may contribute to IBD predisposition in the general population.

The nephroprotective properties of taurine-amikacin treatment in rats are mediated through HSP25 and TLR-4 regulation

Amikacin (AMK) is one of the most effective aminoglycoside antibiotics. However, nephrotoxicity is a major deleterious and dose-limiting side effect associated with its clinical use especially in high dose AMK-treated patients. The present study assessed the ability of taurine (TAU) to alleviate or prevent AMK-induced nephrotoxicity if co-administrated with AMK focusing on inflammation, apoptosis, and fibrosis. Male Sprague Dawley rats were assigned to six equal groups. Group 1: rats received saline (normal control), group 2: normal rats received 50 mg kg^-1 TAU intraperitoneally (i.p.). Groups 3 and 4: received AMK (25 or 50 mg kg^-1; i.p.). Groups 5 and 6: received TAU (50 mg kg^-1; i.p.) concurrently with AMK (25 or 50 mg kg^-1; i.p.) for 3 weeks. AMK-induced nephrotoxicity is evidenced by elevated levels of serum creatinine (CRE), blood urea nitrogen (BUN), and uric acid (UA). Histopathological investigations provoked damaging changes in the renal tissues. Heat shock proteins (HSP)25 and Toll-like receptor-4 (TLR-4) elevated levels were involved in the induction of inflammatory reactions and focal fibrosis. The improved activation of TLR-4 may stimulate monocytes to upgrade Interleukin (IL)-18 production rather than IL-10. TAU proved therapeutic effectiveness against AMK-induced renal toxicity through downregulation of HSP25, TLR-4, caspase-3, and IL-18 with up-regulation of IL-10 levels.

The Role of Heat Shock Proteins in Type 1 Diabetes

Type 1 diabetes (T1D) is a T-cell mediated autoimmune disease characterized by recognition of pancreatic β-cell proteins as self-antigens, called autoantigens (AAgs), followed by loss of pancreatic β-cells. (Pre-)proinsulin ([P]PI), glutamic acid decarboxylase (GAD), tyrosine phosphatase IA-2, and the zinc transporter ZnT8 are key molecules in T1D pathogenesis and are recognized by autoantibodies detected in routine clinical laboratory assays. However, generation of new autoantigens (neoantigens) from β-cells has also been reported, against which the autoreactive T cells show activity. Heat shock proteins (HSPs) were originally described as “cellular stress responders” for their role as chaperones that regulate the conformation and function of a large number of cellular proteins to protect the body from stress. HSPs participate in key cellular functions under both physiological and stressful conditions, including suppression of protein aggregation, assisting folding and stability of nascent and damaged proteins, translocation of proteins into cellular compartments and targeting irreversibly damaged proteins for degradation. Low HSP expression impacts many pathological conditions associated with diabetes and could play a role in diabetic complications. HSPs have beneficial effects in preventing insulin resistance and hyperglycemia in type 2 diabetes (T2D). HSPs are, however, additionally involved in antigen presentation, presenting immunogenic peptides to class I and class II major histocompatibility molecules; thus, an opportunity exists for HSPs to be employed as modulators of immunologic responses in T1D and other autoimmune disorders. In this review, we discuss the multifaceted roles of HSPs in the pathogenesis of T1D and in autoantigen-specific immune protection against T1D development.

Extracellular Chaperones as Novel Biomarkers of Overall Cancer Progression and Efficacy of Anticancer Therapy

Exosomal heat shock proteins (Hsps) are involved in intercellular communication both in physiological and pathological conditions. They play a role in key processes of carcinogenesis including immune system regulation, cell differentiation, vascular homeostasis and metastasis formation. Thus, exosomal Hsps are emerging biomarkers of malignancies and possible therapeutic targets. Adolescents and young adults (AYAs) are patients aged 15–39 years. This age group, placed between pediatric and adult oncology, pose a particular challenge for cancer management. New biomarkers of cancer growth and progression as well as prognostic factors are desperately needed in AYAs. In this review, we attempted to summarize the current knowledge on the role of exosomal Hsps in selected solid tumors characteristic for the AYA population and/or associated with poor prognosis in this age group. These included malignant melanoma, brain tumors, and breast, colorectal, thyroid, hepatocellular, lung and gynecological tract carcinomas. The studies on exosomal Hsps in these tumors are limited; however; some have provided promising results. Although further research is needed, there is potential for future clinical applications of exosomal Hsps in AYA cancers, both as novel biomarkers of disease presence, progression or relapse, or as therapeutic targets or tools for drug delivery.

Participation of Hsp70 and Hsp90α Heat Shock Proteins in Stress Response in the Course of Type 1 Diabetes Mellitus

The role of two heat shock proteins, Hsp70 and Hsp90α, on stress response in mice with severe diabetes mellitus induced by a high dose of alloxan (500 mg/kg body weight), as well as in RIN-m5F β cells cultured in the presence of cytokines (IL-1 and TNF-α) was studied. Our results showed that severe type 1 diabetes mellitus (T1D) caused a higher expression of Hsp90α, but not Hsp70. Moreover, injections of the peroxiredoxin 6 antioxidant enzyme (PRDX6) did not affect the expression of these chaperones. Conversely, pro-inflammatory cytokines added to β-cells caused a significant increase in the expression of Hsp90α and, substantially, Hsp70. Moreover, cells cultivated in the presence of PRDX6 were more susceptible to the cytokine effect. Thus, in the course of severe alloxan-induced T1D, no protective role of the heat shock proteins, was revealed, and their expression level was not increased by PRDX6. At the same time the protective potential of these proteins was shown in vitro with the use of RIN-m5F β cells. Thus, the system of heat shock proteins was unable to prevent the devastating effects of severe T1D accompanied by high animal mortality.

Regulatory/inflammatory cellular response discrimination in operational tolerance

BACKGROUND

Antigen-specific cellular response is essential in immune tolerance. We tested whether antigen-specific cellular response is differentially modulated in operational tolerance (OT) in renal transplantation with respect to critical antigenic challenges in allotransplantation-donor antigens, pathogenic antigens and self-antigens.

METHODS

We analysed the profile of immunoregulatory (REG) and pro-inflammatory (INFLAMMA) cytokines for the antigen-specific response directed to these three antigen groups, by Luminex.

RESULTS

We showed that, in contrast to chronic rejection and healthy individuals, OT gives rise to an immunoregulatory deviation in the cellular response to donor human leucocyte antigen DR isotype peptides, while preserving the pro-inflammatory response to pathogenic peptides. Cellular autoreactivity to the N6 heat shock protein 60 (Hsp60) peptide also showed a REG profile in OT, increasing IL4, IL-5, IL-10 and IL-13.

CONCLUSIONS

The REG shift of donor indirect alloreactivity in OT, with inhibition of interleukin (IL)-1B, IL-8, IL-12, IL-17, granulocyte colony-stimulating factor, Interferon-γ and monocyte chemoattractant protein-1, indicates that this may be an important mechanism in OT. In addition, the differential REG profile of cellular response to the Hsp60 peptide in OT suggests that REG autoimmunity may also play a role in human transplantation tolerance. Despite cross-reactivity of antigen-specific T cell responses, a systemic functional antigen-specific discrimination takes place in OT.

Biomarkers in Stress Related Diseases/Disorders: Diagnostic, Prognostic, and Therapeutic Values

Various internal and external factors negatively affect the homeostatic equilibrium of organisms at the molecular to the whole-body level, inducing the so-called state of stress. Stress affects an organism's welfare status and induces energy-consuming mechanisms to combat the subsequent ill effects; thus, the individual may be immunocompromised, making them vulnerable to pathogens. The information presented here has been extensively reviewed, compiled, and analyzed from authenticated published resources available on Medline, PubMed, PubMed Central, Science Direct, and other scientific databases. Stress levels can be monitored by the quantitative and qualitative measurement of biomarkers. Potential markers of stress include thermal stress markers, such as heat shock proteins (HSPs), innate immune markers, such as Acute Phase Proteins (APPs), oxidative stress markers, and chemical secretions in the saliva and urine. In addition, stress biomarkers also play critical roles in the prognosis of stress-related diseases and disorders, and therapy guidance. Moreover, different components have been identified as potent mediators of cardiovascular, central nervous system, hepatic, and nephrological disorders, which can also be employed to evaluate these conditions precisely, but with stringent validation and specificity. Considerable scientific advances have been made in the detection, quantitation, and application of these biomarkers. The present review describes the current progress of identifying biomarkers, their prognostic, and therapeutic values.

Biomarkers in Stress Related Diseases/Disorders: Diagnostic, Prognostic, and Therapeutic Values

Various internal and external factors negatively affect the homeostatic equilibrium of organisms at the molecular to the whole-body level, inducing the so-called state of stress. Stress affects an organism's welfare status and induces energy-consuming mechanisms to combat the subsequent ill effects; thus, the individual may be immunocompromised, making them vulnerable to pathogens. The information presented here has been extensively reviewed, compiled, and analyzed from authenticated published resources available on Medline, PubMed, PubMed Central, Science Direct, and other scientific databases. Stress levels can be monitored by the quantitative and qualitative measurement of biomarkers. Potential markers of stress include thermal stress markers, such as heat shock proteins (HSPs), innate immune markers, such as Acute Phase Proteins (APPs), oxidative stress markers, and chemical secretions in the saliva and urine. In addition, stress biomarkers also play critical roles in the prognosis of stress-related diseases and disorders, and therapy guidance. Moreover, different components have been identified as potent mediators of cardiovascular, central nervous system, hepatic, and nephrological disorders, which can also be employed to evaluate these conditions precisely, but with stringent validation and specificity. Considerable scientific advances have been made in the detection, quantitation, and application of these biomarkers. The present review describes the current progress of identifying biomarkers, their prognostic, and therapeutic values.

Roles of Extracellular HSPs as Biomarkers in Immune Surveillance and Immune Evasion

Extracellular heat shock proteins (ex-HSPs) have been found in exosomes, oncosomes, membrane surfaces, as well as free HSP in cancer and various pathological conditions, also known as alarmins. Such ex-HSPs include HSP90 (α, β, Gp96, Trap1), HSP70, and large and small HSPs. Production of HSPs is coordinately induced by heat shock factor 1 (HSF1) and hypoxia-inducible factor 1 (HIF-1), while matrix metalloproteinase 3 (MMP-3) and heterochromatin protein 1 are novel inducers of HSPs. Oncosomes released by tumor cells are a major aspect of the resistance-associated secretory phenotype (RASP) by which immune evasion can be established. The concepts of RASP are: (i) releases of ex-HSP and HSP-rich oncosomes are essential in RASP, by which molecular co-transfer of HSPs with oncogenic factors to recipient cells can promote cancer progression and resistance against stresses such as hypoxia, radiation, drugs, and immune systems; (ii) RASP of tumor cells can eject anticancer drugs, targeted therapeutics, and immune checkpoint inhibitors with oncosomes; (iii) cytotoxic lipids can be also released from tumor cells as RASP. ex-HSP and membrane-surface HSP (mHSP) play immunostimulatory roles recognized by CD91+ scavenger receptor expressed by endothelial cells-1 (SREC-1)+ Toll-like receptors (TLRs)+ antigen-presenting cells, leading to antigen cross-presentation and T cell cross-priming, as well as by CD94+ natural killer cells, leading to tumor cytolysis. On the other hand, ex-HSP/CD91 signaling in cancer cells promotes cancer progression. HSPs in body fluids are potential biomarkers detectable by liquid biopsies in cancers and tissue-damaged diseases. HSP-based vaccines, inhibitors, and RNAi therapeutics are also reviewed.

Sympathetic Nerve Hyperactivity in the Spleen: Causal for Nonpathogenic-Driven Chronic Immune-Mediated Inflammatory Diseases (IMIDs)?

Immune-Mediated Inflammatory Diseases (IMIDs) is a descriptive term coined for an eclectic group of diseases or conditions that share common inflammatory pathways, and for which there is no definitive etiology. IMIDs affect the elderly most severely, with many older individuals having two or more IMIDs. These diseases include, but are not limited to, type-1 diabetes, obesity, hypertension, chronic pulmonary disease, coronary heart disease, inflammatory bowel disease, and autoimmunity, such as rheumatoid arthritis (RA), Sjőgren's syndrome, systemic lupus erythematosus, psoriasis, psoriatic arthritis, and multiple sclerosis. These diseases are ostensibly unrelated mechanistically, but increase in frequency with age and share chronic systemic inflammation, implicating major roles for the spleen. Chronic systemic and regional inflammation underlies the disease manifestations of IMIDs. Regional inflammation and immune dysfunction promotes targeted end organ tissue damage, whereas systemic inflammation increases morbidity and mortality by affecting multiple organ systems. Chronic inflammation and skewed dysregulated cell-mediated immune responses drive many of these age-related medical disorders. IMIDs are commonly autoimmune-mediated or suspected to be autoimmune diseases. Another shared feature is dysregulation of the autonomic nervous system and hypothalamic pituitary adrenal (HPA) axis. Here, we focus on dysautonomia. In many IMIDs, dysautonomia manifests as an imbalance in activity/reactivity of the sympathetic and parasympathetic divisions of the autonomic nervous system (ANS). These major autonomic pathways are essential for allostasis of the immune system, and regulating inflammatory processes and innate and adaptive immunity. Pathology in ANS is a hallmark and causal feature of all IMIDs. Chronic systemic inflammation comorbid with stress pathway dysregulation implicate neural-immune cross-talk in the etiology and pathophysiology of IMIDs. Using a rodent model of inflammatory arthritis as an IMID model, we report disease-specific maladaptive changes in β₂-adrenergic receptor (AR) signaling from protein kinase A (PKA) to mitogen activated protein kinase (MAPK) pathways in the spleen. Beta₂-AR signal "shutdown" in the spleen and switching from PKA to G-coupled protein receptor kinase (GRK) pathways in lymph node cells drives inflammation and disease advancement. Based on these findings and the existing literature in other IMIDs, we present and discuss relevant literature that support the hypothesis that unresolvable immune stimulation from chronic inflammation leads to a maladaptive disease-inducing and perpetuating sympathetic response in an attempt to maintain allostasis. Since the role of sympathetic dysfunction in IMIDs is best studied in RA and rodent models of RA, this IMID is the primary one used to evaluate data relevant to our hypothesis. Here, we review the relevant literature and discuss sympathetic dysfunction as a significant contributor to the pathophysiology of IMIDs, and then discuss a novel target for treatment. Based on our findings in inflammatory arthritis and our understanding of common inflammatory process that are used by the immune system across all IMIDs, novel strategies to restore SNS homeostasis are expected to provide safe, cost-effective approaches to treat IMIDs, lower comorbidities, and increase longevity.

Selenium Deficiency Augments the Levels of Inflammatory Factors and Heat Shock Proteins via the Redox Regulatory Pathway in the Skeletal Muscles of Mice

Dietary selenium (Se) deficiency is known to cause myodynia syndrome and Se influences immune responses by changing the expression of inflammatory cytokines and heat shock proteins (Hsps), but the details are not completely elucidated. In the present study, 72 1-day-old mice were divided into two groups; the first group was fed a Se-sufficient diet, while the second group was fed a Se-deficient diet. Skeletal muscles and blood samples were taken from all mice after 42 days of treatment. The activities of glutathione peroxidase (GPX) and glutathione (GSH), mRNA and protein expression levels of inflammatory cytokines (including TNF-α, inducible NO synthase, cyclooxygenase-2, and prostaglandin E synthases), protein expression levels of NF-κB, and the mRNA expression levels of Hsps in the skeletal muscles of mice were examined. The results showed that GPX and GSH activities were decreased, while the mRNA and protein expression levels of inflammatory cytokines and the mRNA levels of Hsps were increased by Se deficiency in mouse skeletal muscles. In the present study, the protective role of Se in oxidative stress, inflammatory cytokines, and Hsps in the skeletal muscles of mice was summarized.

Elevated circulating heat shock protein 70 and its antibody concentrations in chronic spontaneous urticaria

Heat shock proteins (Hsp) play a complex role in cytoprotection, inflammation, and function of the immune system. They may be involved in pathogenesis of various diseases. Our aim was to determine circulating Hsp70 and anti-Hsp70 antibodies concentrations in patients with chronic spontaneous urticaria (CSU). Concentrations of Hsp70 in plasma and anti-Hsp70 antibodies in serum as well as serum C-reactive protein (CRP) were measured in CSU patients and in the controls. Plasma Hsp70 concentrations were significantly higher in CSU (all) and mild CSU patients as compared with the controls. Moderate–severe CSU patients tended to show higher Hsp70 concentration as compared with the controls, but not with mild activity of the disease. There were no significant differences in Hsp70 concentration between moderate–severe and mild CSU patients. Serum anti-Hsp70 antibodies concentrations were significantly higher in CSU (all) and mild CSU in comparison to the controls. Association was observed between anti-Hsp70 antibodies and increased CRP concentration; however, no correlation between anti-Hsp70 and Hsp70 concentrations was seen in the patients. It seems that up-regulation of Hsp70 in CSU may induce marked increase in anti-Hsp70 antibodies production, which are accompanied by parallel changes in CRP concentration. We suggest that Hsp may be released in CSU in response to stressful stimuli, such as inflammation.

No Evidence of Pathological Autoimmunity following Mycobacterium Leprae Heat-Shock Protein 65-Dna Vaccination in Mice

Heat-shock proteins (HSPs) are currently one of the most promising targets for the development of immunotherapy against tumours and autoimmune disorders. This protein family has the capacity to activate or modulate the function of different immune system cells. They induce the activation of monocytes, macrophages and dendritic cells, and contribute to cross-priming, an important mechanism of presentation of exogenous antigen in the context of MHC class I molecules. These various immunological properties of HSP have encouraged their use in several clinical trials. Nevertheless, an important issue regarding these proteins is whether the high homology among HSPs across different species may trigger the breakdown of immune tolerance and induce autoimmune diseases. We have developed a DNA vaccine codifying the Mycobacterium leprae Hsp65 (DNAhsp65), which showed to be highly immunogenic and protective against experimental tuberculosis. Here, we address the question of whether DNAhsp65 immunization could induce pathological autoimmunity in mice. Our results show that DNAhsp65 vaccination induced antibodies that can recognize the human Hsp60 but did not induce harmful effects in 16 different organs analysed by histopathology up to 210 days after vaccination. We also showed that anti-DNA antibodies were not elicited after DNA vaccination. The results are important for the development of both HSP and DNA-based immunomodulatory agents.

Evaluation of the relationship between salivary concentration of anti-heat shock protein immunoglobulin and clinical manifestations of Behçet's disease

OBJECTIVE

This study investigated the relationship between the concentration of anti-heat shock protein (HSP) 60 antibody in resting saliva and the severity of Behçet's disease (BD).

METHOD

Sixty-five patients diagnosed with BD at Tokyo Medical and Dental University Hospital were enrolled in this study. Based on clinical severity scores, patients were categorized as having mild, moderate, or severe BD. Periodontal status was evaluated with the Community Periodontal Index (CPI), and anti-HSP60 antibody concentrations in resting saliva were measured with an enzyme-linked immunosorbent assay.

RESULTS

The mean antibody concentration in patients in the moderate group was significantly higher than concentrations in the mild and severe groups. No significant difference was found between the mild and severe groups. Gingival inflammation, identified with the CPI, was associated with a higher antibody concentration. The antibody concentration in patients who had stomatitis for more than 2 weeks was significantly higher than in those with stomatitis for less than 2 weeks. The antibody concentration in patients who had taken colchicine was significantly lower than that in subjects who had not.

CONCLUSION

These results suggest that the concentration of anti-HSP60 antibody in resting saliva may be effective as a non-invasive indicator for the diagnosis (screening) and prognostication of BD.

pVAXhsp65 Vaccination Primes for High IL-10 Production and Decreases Experimental Encephalomyelitis Severity

Experimental autoimmune encephalomyelitis (EAE) is a demyelinating pathology of the central nervous system (CNS) used as a model to study multiple sclerosis immunopathology. EAE has also been extensively employed to evaluate potentially therapeutic schemes. Considering the presence of an immune response directed to heat shock proteins (hsps) in autoimmune diseases and the immunoregulatory potential of these molecules, we evaluated the effect of a previous immunization with a genetic vaccine containing the mycobacterial hsp65 gene on EAE development. C57BL/6 mice were immunized with 4 pVAXhsp65 doses and 14 days later were submitted to EAE induction by immunization with myelin oligodendrocyte glycoprotein (MOG_35–55) emulsified in Complete Freund's Adjuvant. Vaccinated mice presented significant lower clinical scores and lost less body weight. MOG_35–55 immunization also determined less inflammation in lumbar spinal cord but did not change CD4+CD25+Foxp3+ T cells frequency in spleen and CNS. Infiltrating cells from the CNS stimulated with rhsp65 produced significantly higher levels of IL-10. These results suggest that the ability of pVAXhsp65 vaccination to control EAE development is associated with IL-10 induction.

Hsp65-Producing Lactococcus lactis Prevents Inflammatory Intestinal Disease in Mice by IL-10- and TLR2-Dependent Pathways

Heat shock proteins (Hsps) are highly expressed at all sites of inflammation. As they are ubiquitous and immunodominant antigens, these molecules represent good candidates for the therapeutic use of oral tolerance in autoimmune and chronic inflammatory diseases. Evidences from human and animal studies indicate that inflammatory bowel disease (IBD) results from uncontrolled inflammatory responses to intestinal microbiota. Hsps are immunodominant proteins expressed by several immune cells and by commensal bacteria. Using an IBD mouse model, we showed that oral pretreatment with genetically modified Lactococcus lactis that produces and releases Mycobacterium Hsp65, completely prevented DSS-induced colitis in C57BL/6 mice. Protection was associated with reduced pro-inflammatory cytokines, such as IFN-γ, IL-6, and TNF-α; increased IL-10 production in colonic tissue; and expansion of CD4⁺Foxp3⁺ and CD4⁺LAP⁺ regulatory T cells in spleen and mesenteric lymph nodes. This effect was dependent on IL-10 and toll-like receptor 2. Thus, this approach may open alternative options for long-term management of IBD.

The western-type diet induces anti-HMGB1 autoimmunity in Apoe(-/-) mice

BACKGROUND AND AIMS

Anti-HMGB1 autoimmunity plays a role in systemic lupus erythematosus (SLE). Because SLE increases atherosclerosis, we asked whether the same autoimmunity might play a role in atherogenesis.

METHODS

We looked for the induction of HMGB1-specific B and T cell responses by a western-type diet (WTD) in the Apoe(-/-) mouse model of atherosclerosis. We also determined whether modifying the responses modulates atherosclerosis.

RESULTS

In the plasma of male Apoe(-/-) mice fed WTD, the level of anti-HMGB1 antibodies (Abs) was detected at ∼50 μg/ml, which was ∼6 times higher than that in either Apoe(-/-) mice fed a normal chow or Apoe(+/+) mice fed WTD (p ≤ 0.0005). The Abs were directed largely toward a novel, dominant epitope of HMGB1 named HMW4; accordingly, compared with chow-fed mice, WTD-fed Apoe(-/-) mice had more activated HMW4-reactive B and T cells (p = 0.005 and p = 0.01, respectively). Compared with mock-immunized mice, Apoe(-/-) mice immunized with HMW4 along with an immunogenic adjuvant showed proportional increases in anti-HMW4 IgG and IgM Abs, HMW4-reactive B-1 and B-2 cells, and HMW4-reactive Treg and Teff cells, which was associated with ∼30% increase in aortic arch lesions (p ≤ 0.01) by two methods. In contrast, Apoe(-/-) mice immunized with HMW4 using a tolerogenic adjuvant showed preferential increases in anti-HMW4 IgM (over IgG) Abs, HMW4-reactive B-1 (over B-2) cells, and HMW4-specific Treg (over Teff) cells, which was associated with ∼40% decrease in aortic arch lesions (p ≤ 0.03).

CONCLUSIONS

Anti-HMGB1 autoimmunity may potentially play a role in atherogenesis.

The Microbiota Determines Susceptibility to Experimental Autoimmune Uveoretinitis

The microbiota is a crucial modulator of the immune system. Here, we evaluated how its absence or reduction modifies the inflammatory response in the murine model of experimental autoimmune uveoretinitis (EAU). We induced EAU in germ-free (GF) or conventionally housed (CV) mice and in CV mice treated with a combination of broad-spectrum antibiotics either from the day of EAU induction or from one week prior to induction of disease. The severity of the inflammation was assessed by fundus biomicroscopy or by histology, including immunohistology. The immunophenotyping of T cells in local and distant lymph nodes was performed by flow cytometry. We found that GF mice and mice where the microbiota was reduced one week before EAU induction were protected from severe autoimmune inflammation. GF mice had lower numbers of infiltrating macrophages and significantly less T cell infiltration in the retina than CV mice with EAU. GF mice also had reduced numbers of IFN-γ and IL-17-producing T cells and increased numbers of regulatory T cells in the eye-draining lymph nodes. These data suggest that the presence of microbiota during autoantigen recognition regulates the inflammatory response by influencing the adaptive immune response.

Inflammatory mechanisms linking periodontal diseases to cardiovascular diseases

AIMS

In this article, inflammatory mechanisms that link periodontal diseases to cardiovascular diseases are reviewed.

METHODS

This article is a literature review.

RESULTS

Studies in the literature implicate a number of possible mechanisms that could be responsible for increased inflammatory responses in atheromatous lesions due to periodontal infections. These include increased systemic levels of inflammatory mediators stimulated by bacteria and their products at sites distant from the oral cavity, elevated thrombotic and hemostatic markers that promote a prothrombotic state and inflammation, cross-reactive systemic antibodies that promote inflammation and interact with the atheroma, promotion of dyslipidemia with consequent increases in pro-inflammatory lipid classes and subclasses, and common genetic susceptibility factors present in both disease leading to increased inflammatory responses.

CONCLUSIONS

Such mechanisms may be thought to act in concert to increase systemic inflammation in periodontal disease and to promote or exacerbate atherogenesis. However, proof that the increase in systemic inflammation attributable to periodontitis impacts inflammatory responses during atheroma development, thrombotic events or myocardial infarction or stroke is lacking.

Unfolding the Role of Large Heat Shock Proteins: New Insights and Therapeutic Implications

Heat shock proteins (HSPs) of eukaryotes are evolutionarily conserved molecules present in all the major intracellular organelles. They mainly function as molecular chaperones and participate in maintenance of protein homeostasis in physiological state and under stressful conditions. Despite their relative abundance, the large HSPs, i.e., Hsp110 and glucose-regulated protein 170 (Grp170), have received less attention compared to other conventional HSPs. These proteins are distantly related to the Hsp70 and belong to Hsp70 superfamily. Increased sizes of Hsp110 and Grp170, due to the presence of a loop structure, result in their exceptional capability in binding to polypeptide substrates or non-protein ligands, such as pathogen-associated molecules. These interactions that occur in the extracellular environment during tissue injury or microbial infection may lead to amplification of an immune response engaging both innate and adaptive immune components. Here, we review the current advances in understanding these large HSPs as molecular chaperones in proteostasis control and immune modulation as well as their therapeutic implications in treatment of cancer and neurodegeneration. Given their unique immunoregulatory activities, we also discuss the emerging evidence of their potential involvement in inflammatory and immune-related diseases.

HSP90 Inhibitor Geldanamycin as a Radiation Response Modificator in Human Blood Cells

Heat shock protein 90 (Hsp90) is a highly conserved molecular chaperone, involved in the folding, assembly, stabilization and activation of numerous proteins with unrelated amino acid sequences and functions. Geldanamycin (GA), a natural benzoquinone, can inhibit the chaperone activity of Hsp90. It has been shown that GA can produce superoxide anions and increase the intracellular oxidative stress, which, in addition to the direct inhibition of Hsp90, might also contribute to the modifying effects of the inhibitor on the early response in human mononuclear cells exposed to ionizing radiation. The present study shows that GA antagonizes the radiation-induced suppression on MnSOD and catalase, key enzymes of the radical scavenging systems. By significantly up-regulating catalase levels over the entire range of doses from 0.5 to 4 Gy, the inhibitor of Hsp90 exerted adaptive protection and modified the early radiation response of the human blood cells.

Selenoproteins and heat shock proteins play important roles in immunosuppression in the bursa of Fabricius of chickens with selenium deficiency

Selenium (Se) is necessary for the immune system in chicken and mediates its physiological functions through selenoproteins. Heat shock proteins (Hsps) are indispensable for maintaining normal cell function and for directing the immune response. The aim of the present study was to investigate the effects of Se deficiency on the messenger ribonucleic acid (mRNA) expression levels of selenoproteins and Hsps as well as immune functions in the chicken bursa of Fabricius. Two groups of chickens, namely the control and Se-deficient (L group) groups, were reared for 55 days. The chickens were offered a basal diet, which contained 0.15 mg Se/kg in the diet fed to the control group and 0.033 mg Se/kg in the diet fed to the L group. We performed real-time quantitative polymerase chain reaction to detect the mRNA expression levels of selenoproteins and Hsps on days 15, 25, 35, 45 and 55. Western blotting was used to determine the protein expression levels of Hsps on days 35, 45 and 55, and immune functions were assessed through an enzyme-linked immunosorbent assay on days 15, 35, and 55. The data showed that the mRNA expression levels of selenoproteins, such as Txnrd1, Txnrd2, Txnrd3, Dio1, Dio2, Dio3, GPx1, GPx2, GPx3 GPx4, Sepp1, Selo, Sel-15, Sepx1, Sels, Seli, Selu, Selh, and SPS2, were significantly lower (P < 0.05) in the L group compared with the control group. Additionally, the mRNA and protein expression levels of Hsps (Hsp27, Hsp40, Hsp60, Hsp70, and Hsp90) were also significantly higher (P < 0.05) in the L group. The expression levels of IL-2, IL-6, IL-8, IL-10, IL-17, IL-1β, IFN-α, IFN-β, and IFN-γ were significantly lower (P < 0.05) and TNF-α was significantly higher (P < 0.05) in the L group compared with the control group. Our results show that immunosuppression was accompanied by a downregulation of mRNA expression levels of selenoproteins and an upregulation of the Hsp mRNA expression levels. Thus, Se deficiency causes defects in the chicken bursa of Fabricius, and selenoproteins and Hsps play important roles in immunosuppression in the bursa of Fabricius of chickens with Se deficiency.

Neonatal Death and Heart Failure in Mouse with Transgenic HSP60 Expression

Mitochondrial heat shock proteins, such as HSP60, are chaperones responsible for the folding, transport, and quality control of mitochondrial matrix proteins and are essential for maintaining life. Both prosurvival and proapoptotic roles have been proposed for HSP60, and HSP60 is reportedly involved in the initiation of autoimmune, metabolic, and cardiovascular diseases. The role of HSP60 in pathogenesis of these diseases remains unclear, partly because of the lack of mouse models expressing HSP60. In this study we generated HSP60 conditional transgenic mice suitable for investigating in vivo outcomes by expressing HSP60 at the targeted organ in disease models. Ubiquitous HSP60 induction in the embryonic stage caused neonatal death in mice at postnatal day 1. A high incidence of atrial septal defects was observed in HSP60-expressing mice, with increased apoptosis and myocyte degeneration that possibly contributed to massive hemorrhage and sponge-like cardiac muscles. Our results showed that neonatal heart failure through HSP60 induction likely involves developmental defects and excessive apoptosis. The conditional HSP60 mouse model is useful for studying crucial biological questions concerning HSP60.

Significance of serum antibodies against HSP 60 and HSP 70 for the diagnostic of infectious diseases

Heat shock proteins (HSP) represent important antigenic targets for the immune response, playing an important role in the pathology and infectious diseases control. The purpose of this work was to investigate the levels of HSP60 and HSP70 specific antibodies in the bloodstream of patients with different bacterial infections and cancer, in order to evaluate their potential role as diagnosis markers of different infectious diseases. Detection of specific anti-HSP 60 and HSP 70 serum levels was performed by ELISA. Statistical analysis of data by multivariate logistic regression was performed using GraphPadPrism software and statistical tests based on chi-square and Student t-test. High levels of anti-HSP60 were found in patients with localized infections, while the levels of anti- HSP70 were higher in the group with generalized infections. The serum levels of both anti-HSP 60 and anti-HSP70 were significantly increased in patients with Gram-negative bacterial infections, as compared with patients harbouring infections produced by Gram-positive and fungal strains, demonstrating their potential use as additional diagnosis and prognosis markers in infections with this etiology.

Genomic profiles and predictors of early allograft dysfunction after human liver transplantation

Early hepatic allograft dysfunction (EAD) manifests posttransplantation with high serum transaminases, persistent cholestasis, and coagulopathy. The biological mechanisms are poorly understood. This study investigates the molecular mechanisms involved in EAD and defines a gene expression signature revealing different biological pathways in subjects with EAD from those without EAD, a potential first step in developing a molecular classifier as a potential clinical diagnostic. Global gene expression profiles of 30 liver transplant recipients of deceased donor grafts with EAD and 26 recipients without graft dysfunction were investigated using microarrays of liver biopsies performed at the end of cold storage and after graft reperfusion prior to closure. Results reveal a shift in inflammatory and metabolic responses between the two time points and differences between EAD and non-EAD. We identified relevant pathways (PPARα and NF-κB) and targets (such as CXCL1, IL1, TRAF6, TIPARP, and TNFRSF1B) associated with the phenotype of EAD. Preliminary proof of concept gene expression classifiers that distinguish EAD from non-EAD patients, with Area Under the Curve (AUC) >0.80 were also identified. This data may have mechanistic and diagnostic implications for EAD.

Could mycobacterial Hsp70-containing fusion protein lead the way to an affordable therapeutic cancer vaccine?

Cancer vaccine development efforts have recently gained momentum, but most vaccines showing clinical impact in human trials tend to be based on technology approaches that are very costly and difficult to produce at scale. With the projected doubling of the incidence of cancer and its related cost of care in the U.S. over the next two decades, the widespread clinical use of such vaccines will prove difficult to justify. Heat shock protein-based vaccines have shown the potential to elicit clinically meaningful immunologic responses in cancer, but the predominant development approach - heat shock protein-peptide complexes derived from a patient's own tumor - face similar challenges of cost and scalability. New innovative modalities for deploying heat shock proteins in cancer vaccines may open the door to vaccines that can generate potent cytotoxic responses against multiple tumor targets and can be made in a cost-effective and scalable manner.

The implication of periodontitis in vascular endothelial dysfunction

BACKGROUND

Periodontitis is the most common oral infection seen in humans worldwide. It is characterized by gradual destruction of tooth supporting tissues, eventually leading to loss of tooth. The periodontal biofilm associated with periodontitis comprises of gram-positive and gram-negative bacteria, instrumental for the initiation and progression of periodontitis. Evidence-based literature has identified the nature of periodontal infection as a possible causative condition in the inducement of 'low-grade systemic inflammation and infection'. The periodontal pathogens exert systemic effects via the haematogenous route.

AIM

The present review provides an insight into the pathophysiology of the endothelial dysfunction with reference to periodontal infection and highlights the association between periodontitis and endothelial dysfunction. Various studies addressing the implication of periodontitis on endothelial dysfunction will be described, with a focus of periodontal treatment on improvement of endothelial function.

MATERIALS AND METHODS

Studies examining the effects of periodontitis on vascular endothelial function were segregated. Studies conducted on both animal and human models were identified using MEDLINE database search with key search terms such as 'Periodontitis', 'vascular endothelium', 'endothelial dysfunction', 'periodontal bacteria' and 'periodontal therapy'. Systematic reviews and meta-analysis were also screened. Only studies published in English language were considered. The review has been prepared by screening MEDLINE database from 1989 to 2012.

RESULTS AND CONCLUSIONS

Chronic periodontitis results in altered vascular response, increased expression of pro-inflammatory cytokines and adhesion molecules inducing vascular endothelial dysfunction. Periodontal therapy may ameliorate the perturbed vascular endothelial function.

Heat shock proteins and cardiovascular disease

Atherosclerosis is the leading global cause of mortality, morbidity, and disability. Heat shock proteins (HSPs) are a highly conserved family of proteins with diverse functions expressed by all cells exposed to environmental stress. Studies have reported that several HSPs may be potential risk markers of atherosclerosis and related cardiovascular diseases, or may be directly involved in the atherogenic process itself. HSPs are expressed by cells in atherosclerotic plaque and anti-HSP has been reported to be increased in patients with vascular disease. Autoimmune responses may be generated against antigens present within the atherosclerotic plaque, including HSP and may lead to a cycle of ongoing vascular injury. It has been suggested that by inducing a state of tolerance to these antigens, the atherogenic process may be limited and thus provide a potential therapeutic approach. It has been suggested that anti-HSPs are independent predictors of risk of vascular disease. In this review, we summarize the current understanding of HSP in cardiovascular disease and highlight their potential role as diagnostic agents and therapeutic targets.

Expression and regulation of toll-like receptors (TLRs) in human intervertebral disc cells

PURPOSE

Although inflammatory processes play an essential role in painful intervertebral disc (IVD) degeneration, the underlying regulatory mechanisms are not well understood. This study was designed to investigate the expression, regulation and importance of specific toll-like receptors (TLRs)--which have been shown to play an essential role e.g. in osteoarthritis--during degenerative disc disease.

METHODS

The expression of TLRs in human IVDs was measured in isolated cells as well as in normal or degenerated IVD tissue. The role of IL-1β or TNF-α in regulating TLRs (expression/activation) as well as in regulating activity of down-stream pathways (NF-κB) and expression of inflammation-related genes (IL-6, IL-8, HSP60, HSP70, HMGB1) was analyzed.

RESULTS

Expression of TLR1/2/3/4/5/6/9/10 was detected in isolated human IVD cells, with TLR1/2/4/6 being dependent on the degree of IVD degeneration. Stimulation with IL-1β or TNF-α moderately increased TLR1/TLR4 mRNA expression (TNF-α only), and strongly increased TLR2 mRNA expression (IL-1β/TNF-α), with the latter being confirmed on the protein level. Stimulation with IL-1β, TNF-α or Pam3CSK4 (a TLR2-ligand) stimulated IL-6 and IL-8, which was inhibited by a TLR2 neutralizing antibody for Pam3CSK4; IL-1β and TNF-α caused NF-κB activation. HSP60, HSP70 and HMGB1 did not increase IL-6 or IL-8 and were not regulated by IL-1β/TNF-α.

CONCLUSION

We provide evidence that several TLRs are expressed in human IVD cells, with TLR2 possibly playing the most crucial role. As TLRs mediate catabolic and inflammatory processes, increased levels of TLRs may lead to aggravated disc degeneration, chronic inflammation and pain development. Especially with the identification of more endogenous TLR ligands, targeting these receptors may hold therapeutic promise.

T cell recognition of naturally presented epitopes of self-heat shock protein 70

Self-reactive T cells have shown to have a potential role as regulators of the immune system preventing or even suppressing autoimmunity. One of the most abundant proteins that can be eluted from human HLA molecules is heat shock protein 70 (HSP70). The aims of the current study are to identify HSP70 epitopes based on published HLA elution studies and to investigate whether T cells from healthy individuals may respond to such self-epitopes. A literature search and subsequent in silico binding prediction based on theoretical MHC binding motifs resulted in the identification of seven HSP70 epitopes. PBMCs of healthy controls proliferated after incubation with two of the seven peptides (H167 and H290). Furthermore H161, H290, and H443 induced CD69 expression or production of cytokines IFNγ or TNFα in healthy controls. The identification of these naturally presented epitopes and the response they elicit in the normal immune system make them potential candidates to study during inflammatory conditions as well as in autoimmune diseases.

Immunomodulation in human and experimental arthritis: including vitamin D, helminths and heat-shock proteins

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that is mainly directed to the joints, affecting the synovial membrane, the cartilage and also the bone. This disease affects 1% to 2% of the world population and is associated with significant morbidity and increased mortality. RA experimental models have allowed a great deal of information to be translated to the corresponding human disease. This review summarizes some of the most relevant findings targeting immunomodulation in arthritis. Some general guidelines to choose an adequate experimental model and also our experience with arthritis are supplied.

Mycobacterium leprae Hsp65 administration reduces the lifespan of aged high antibody producer mice

BACKGROUND

Aging process may result in immune modifications that lead to disruption of innate and acquired immunity mechanisms that may induce chronic-degenerative events. The heat shock proteins (Hsp), phylogeneticaly conserved among organisms, present as main function the ability of folding and refolding proteins, but they also are associated with chronic-degenerative disorders. Here were evaluated the role of M. leprae native Hsp65 (WT) and its point-mutated (K409A) on survival and anti-DNA and anti-Hsp65 antibody production of aged genetically selected mice for high (HIII) and low (LIII) antibody production; data from 120- and 270-days old mice (named "adult" or "aged", respectively) were compared.

RESULTS

WT Hsp65 administration induces reduction in the mean survival time of adult and aged female HIII mice, this effect being stronger in aged individuals. Surprisingly, the native protein administration increased the survival of aged female LIII when compared to K409A and control groups. No survival differences were observed in aged male mice after Hsp65 proteins inoculation. We observed increase in IgG1 anti-Hsp65 in WT and K409A aged HIII female mice groups and no marked changes in the anti-DNA (adult and aged HIII) and anti-Hsp65 IgG1 or IgG2a isotypes production in adult HIII female and aged male mice. LIII male mice presented increased anti-DNA and anti-Hsp65 IgG2a isotype production after WT or K409A injection, and LIII female groups showed no alterations.

CONCLUSIONS

The results revealed that the WT Hsp65 interferes with survival of aged HIII female mice without involvement of a remarkable IgG1 and IgG2a anti-DNA and anti-Hsp65 antibodies production. The deleterious effects of Hsp65 on survival time in aged HIII female mice could be linked to a gender-effect and are in agreement with those previously reported in lupus-prone mice.

Function and Potentials of M. tuberculosis Epitopes

Study of the function of epitopes of Mycobacterium tuberculosis antigens contributed significantly toward better understanding of the immunopathogenesis and to efforts for improving infection and disease control. Characterization of genetically permissively presented immunodominant epitopes has implications for the evolution of the host–parasite relationship, development of immunodiagnostic tests, and subunit prophylactic vaccines. Knowledge of the determinants of cross-sensitization, relevant to other pathogenic or environmental mycobacteria and to host constituents has advanced. Epitope-defined IFNγ assay kits became established for the specific detection of infection with tubercle bacilli both in humans and cattle. The CD4 T-cell epitope repertoire was found to be more narrow in patients with active disease than in latently infected subjects. However, differential diagnosis of active TB could not be made reliably merely on the basis of epitope recognition. The mechanisms by which HLA polymorphism can influence the development of multibacillary tuberculosis (TB) need further analysis of epitopes, recognized by Th2 helper cells for B-cell responses. Future vaccine development would benefit from better definition of protective epitopes and from improved construction and formulation of subunits with enhanced immunogenicity. Epitope-defined serology, due to its operational advantages is suitable for active case finding in selected high disease incidence populations, aiming for an early detection of infectious cases and hence for reducing the transmission of infection. The existing knowledge of HLA class I binding epitopes could be the basis for the construction of T-cell receptor-like ligands for immunotherapeutic application. Continued analysis of the functions of mycobacterial epitopes, recognized by T cells and antibodies, remains a fertile avenue in TB research.

Downmodulation of peripheral MOG-specific immunity by pVAXhsp65 treatment during EAE does not reach the CNS

Most of the therapeutic strategies to control multiple sclerosis are directed to immune modulation and inflammation control. As heat shock proteins are able to induce immunoregulatory T cells, we investigated the therapeutic effect of a genetic vaccine containing the mycobacterial hsp65 gene on experimental autoimmune encephalomyelitis (EAE). Although pVAXhsp65 was immunogenic for mice with EAE and downmodulated specific cytokine induction by MOG, therapy was not able to decrease clinical severity nor to modify immunologic parameters in the CNS. These results indicate that hsp65, administered as a DNA vaccine, was not therapeutic for EAE.

Innate and Adaptive Responses to Heat Shock Proteins in Behcet's Disease

Behcet's disease (BD) is a systemic, chronic inflammatory disorder with both innate and adaptive immune responses. Heat shock proteins (HSP) are highly conserved molecules in different species with scavenger activity and involved in correct folding of newly synthesized proteins. T and B cell responses against HSPs are observed in BD patients in both αβ and γδ T-cell populations. 60-kD HSP (HSP60) is also shown to be recognized by pattern recognition receptors such as toll-like receptors (TLR) and is suggested to be an endogenous "danger" signal to the immune system with rapid inflammatory cytokine releases and enhancement of adaptive Th1-type responses. Elucidating the exact role of HSPs in BD pathogenesis might pave the way to less toxic therapeutic approaches to BD, such as antibacterial therapies and immunomodulation.

Up-regulation of inducible heat shock protein-70 expression in multiple sclerosis patients

Inducible heat shock protein (HSP)70 (HSP70-1A and HSP70-1B proteins) is a chaperone responsible for assisting proper protein folding. Following stress conditions, HSP70 is highly up-regulated to mediate cytoprotective functions. In addition, HSP70 is able to trigger innate and adaptive immune responses that promote the immune recognition of antigens and to act as a cytokine when it is released. The data in the literature are controversial with regard to expression studies in peripheral blood mononuclear cells (PBMCs). In the present study, we aimed to examine if alterations of HSP70-1A/B expression are involved in the autoimmune pathogenesis of multiple sclerosis (MS). We determined both mRNA and protein expression in PBMCs of MS patients and healthy donors (HDs). We found a baseline increased expression of the HSPA1A gene in PBMCs from MS patients compared with HDs. Gene expression findings were associated with an increased protein expression of HSP70-1A/B in T lymphocytes (CD4+ and CD8+) and monocytes from MS patients under basal conditions that may reflect the immunological activation occurring in MS patients. We also provided evidence that heat shock (HS) stimulus induced HSP70-1A/B protein expression in HDs and MS patients, and that HS-induced HSP70-1A/B protein expression in monocytes correlated with the number of T2 lesions at baseline in MS patients. However, after lipopolysaccharide inflammatory stimulus, monocytes from MS patients failed to induce HSP70-1A/B protein expression. Our data hint at altered immune responses in MS and may indicate either a state of chronic stress or increased vulnerability to physiological immune responses in MS patients.

BCG and BCG/DNAhsp65 vaccinations promote protective effects without deleterious consequences for experimental autoimmune encephalomyelitis

A prime-boost strategy conserving BCG is considered the most promising vaccine to control tuberculosis. A boost with a DNA vaccine containing the mycobacterial gene of a heat shock protein (pVAXhsp65) after BCG priming protected mice against experimental tuberculosis. However, anti-hsp65 immunity could worsen an autoimmune disease due to molecular mimicry. In this investigation, we evaluated the effect of a previous BCG or BCG/pVAXhsp65 immunization on experimental autoimmune encephalomyelitis (EAE) development. Female Lewis rats were immunized with BCG or BCG followed by pVAXhsp65 boosters. The animals underwent EAE induction and were daily evaluated for weight loss and clinical score. They were euthanized during recovery phase to assess immune response and inflammatory infiltration at the central nervous system. Previous immunization did not aggravate or accelerate clinical score or weight loss. In addition, this procedure clearly decreased inflammation in the brain. BCG immunization modulated the host immune response by triggering a significant reduction in IL-10 and IFN-γ levels induced by myelin basic protein. These data indicated that vaccination protocols with BCG or BCG followed by boosters with pVAXhsp65 did not trigger a deleterious effect on EAE evolution.