Heat shock protein 60 inhibits Th1-mediated hepatitis model via innate regulation of Th1/Th2 transcription factors and cytokines

6-Formylindolo[3,2-b]carbazole, a potent ligand for the aryl hydrocarbon receptor, attenuates concanavalin-induced hepatitis by limiting T-cell activation and infiltration of proinflammatory CD11b+ Kupffer cells

FICZ (6-formylindolo[3,2-b]carbazole) is a potent aryl hydrocarbon receptor agonist that has a poorly understood function in the regulation of inflammation. In this study, we investigated the effect of aryl hydrocarbon receptor activation by FICZ in a murine model of autoimmune hepatitis induced by concanavalin A. High-throughput sequencing techniques such as single-cell RNA sequencing and assay for transposase accessible chromatin sequencing were used to explore the mechanisms through which FICZ induces its effects. FICZ treatment attenuated concanavalin A-induced hepatitis, evidenced by decreased T-cell infiltration, decreased circulating alanine transaminase levels, and suppression of proinflammatory cytokines. Concanavalin A revealed an increase in natural killer T cells, T cells, and mature B cells upon concanavalin A injection while FICZ treatment reversed the presence of these subsets. Surprisingly, concanavalin A depleted a subset of CD55+ B cells, while FICZ partially protected this subset. The immune cells showed significant dysregulation in the gene expression profiles, including diverse expression of migratory markers such as CCL4, CCL5, and CXCL2 and critical regulatory markers such as Junb. Assay for transposase accessible chromatin sequencing showed more accessible chromatin in the CD3e promoter in the concanavalin A-only group as compared to the naive and concanavalin A-exposed, FICZ-treated group. While there was overall more accessible chromatin of the Adgre1 (F4/80) promoter in the FICZ-treated group, we observed less open chromatin in the Itgam (CD11b) promoter in Kupffer cells, supporting the ability of FICZ to reduce the infiltration of proinflammatory cytokine producing CD11b+ Kupffer cells. Taken together, these data demonstrate that aryl hydrocarbon receptor activation by FICZ suppresses liver injury through the limitation of CD3+ T-cell activation and CD11b+ Kupffer cell infiltration.

Intermittent mild cold acclimation ameliorates intestinal inflammation and immune dysfunction in acute cold-stressed broilers by regulating the TLR4/MyD88/NF-κB pathway

To investigate the potential protective effect of prior cold stimulation on broiler intestine induced by acute cold stress (ACS). A total of 384 one-day-old broilers were divided into control (CON), ACS, cold stimulation Ⅰ (CS3+ACS), and cold stimulation Ⅱ (CS9+ACS) groups. Broilers in CON and ACS groups were reared normally, and birds in CS3+ACS and CS9+ACS groups were reared at 3℃ and 9℃ below CON group for 5 h, respectively, on alternate days from d 15 to 35. Broilers in ACS, CS3+ACS, and CS9+ACS groups were subjected to 10℃ for 24 h on d 43. Eventually, small intestine tissues were collected for histopathological observation and indexes detection. The results showed that intestinal tissues in all ACS-broilers exhibited inflammatory cell infiltrates, microvilli disruption, reduced villus length in jejunum and increased crypt depth in jejunum and ileum. Whereas these phenomena were relatively light in CS3+ACS group. Compared to CON group, mRNA expression of the TLR4/MyD88/NF-κB pathway-related genes (TLR4, MyD88, NF-κBp65, COX-2, iNOS, PTGEs, TNF-α), Th1/Th17-derived cytokines (IL-1β, IL-2, IL-8, IL-12, IFN-γ, IL-17), and HSPs (HSP40, HSP60, HSP70, HSP90) was upregulated (P < 0.05), and that of Th2-deviated cytokines (IL-4, IL-6, IL-10, IL-13) and IκBα was downregulated (P < 0.05) in small intestine in almost all ACS-broilers. Compared to ACS group, mRNA expression of most of the TLR4/MyD88/NF-κB pathway-related genes, Th1/Th17-derived cytokines, and HSPs was downregulated and that of Th2-derived cytokines was upregulated in CS3+ACS group (P < 0.05). Protein expression levels of TLR4, MyD88, p-p65/p65, p-IκBα/IκBα, IKK, TNF-α, IL-1β, IL-10, and HSPs were similar to their mRNA expression. The concentration of sIgA and activities of CAT, SOD, and GSH-px were decreased and MDA and H2O2 were increased in ACS and CS9+ACS groups compared to CON group (P < 0.05). Therefore, cold stress caused oxidative stress and inflammation, leading to gut immune dysfunction; while mild cold stimulation at 3℃ below normal rearing temperature alleviated cold stress-induced intestinal injure and dysfunction by modulating the TLR4/MyD88/NF-κB pathway in broilers.

Differential Protein Expression of Taenia crassiceps ORF Strain in the Murine Cysticercosis Model Using Resistant (C57BL/6) Mice

A cysticercosis model of Taenia crassiceps ORF strain in susceptible BALB/c mice revealed a Th2 response after 4 weeks, allowing for the growth of the parasite, whereas resistant C57BL/6 mice developed a sustained Th1 response, limiting parasitic growth. However, little is known about how cysticerci respond to an immunological environment in resistant mice. Here, we show that the Th1 response, during infection in resistant C57BL/6 mice, lasted up to 8 weeks and kept parasitemia low. Proteomics analysis of parasites during this Th1 environment showed an average of 128 expressed proteins; we chose 15 proteins whose differential expression varied between 70 and 100%. A total of 11 proteins were identified that formed a group whose expression increased at 4 weeks and decreased at 8 weeks, and another group with proteins whose expression was high at 2 weeks and decreased at 8 weeks. These identified proteins participate in tissue repair, immunoregulation and parasite establishment. This suggests that T. crassiceps cysticerci in mice resistant under the Th1 environment express proteins that control damage and help to establish a parasite in the host. These proteins could be targets for drugs or vaccine development.

Immune and Genomic Analysis of Boxer Dog Breed and Its Relationship with Leishmania infantum Infection

Simple Summary

Leishmaniosis is a zoonotic disease, endemic in 88 countries, including those from the Mediterranean region. Several authors indicate differences in susceptibility and resistance to leishmaniosis in different canine breeds, with boxer being one of the breeds with a higher prevalence of the disease. This study analyzes the serum profiles of cytokines related to the immune response, together with the screening of genomic variants fixed in boxer breed samples, to understand their differential susceptibility to L. infantum infection. The results of this study indicate new pathways related to L. infantum infection and immune response in boxers, involving genes related to interleukin and toll-like receptors, as well as to the immune system and the regulation of expression. Future studies are required to elucidate the role of specific genes in the L. infantum infection mechanism in this canine breed.

Abstract

Leishmaniosis, one of the most important zoonoses in Europe, is caused by Leishmania infantum, an intracellular protozoan parasite. This disease is endemic in the Mediterranean area, where the main reservoir is the dog. Several studies indicate a possible susceptibility to L. infantum infection with clinical signs in some canine breeds. One of them is the boxer breed, which shows a high prevalence of disease. In this study, immunological and genomic characterization of serum samples from boxer dogs living in the Mediterranean area were evaluated to analyze the immune response and the possible genetic explanation for this susceptibility. Serum levels of cytokines IFN-γ, IL-2, IL-6, IL-8, and IL-18 were determined by ELISA commercial tests, while the genotyping study was performed using the CanineHD DNA Analysis BeadChip. The results show relevant differences in the serum levels of cytokines compared to published data on other canine breeds, as well as sequence changes that could explain the high susceptibility of the boxer breed to the disease. Concretely, polymorphic variants in the CIITA, HSF2BP, LTBP1, MITF, NOXA1, PKIB, RAB38, RASEF, TLE1, and TLR4 genes were found, which could explain the susceptibility of this breed to L. infantum infection.

Heat Shock Protein 60 Restricts Release of Mitochondrial dsRNA to Suppress Hepatic Inflammation and Ameliorate Non-Alcoholic Fatty Liver Disease in Mice

Non-alcoholic fatty liver disease (NAFLD), the most common cause of chronic liver disease, consists of fat deposited (steatosis) in the liver due to causes besides excessive alcohol use. The folding activity of heat shock protein 60 (HSP60) has been shown to protect mitochondria from proteotoxicity under various types of stress. In this study, we investigated whether HSP60 could ameliorate experimental high-fat diet (HFD)-induced obesity and hepatitis and explored the potential mechanism in mice. The results uncovered that HSP60 gain not only alleviated HFD-induced body weight gain, fat accumulation, and hepatocellular steatosis, but also glucose tolerance and insulin resistance according to intraperitoneal glucose tolerance testing and insulin tolerance testing in HSP60 transgenic (HSP60Tg) compared to wild-type (WT) mice by HFD. Furthermore, overexpression of HSP60 in the HFD group resulted in inhibited release of mitochondrial dsRNA (mt-dsRNA) compared to WT mice. In addition, overexpression of HSP60 also inhibited the activation of toll-like receptor 3 (TLR3), melanoma differentiation-associated gene 5 (MDA5), and phosphorylated-interferon regulatory factor 3 (p-IRF3), as well as inflammatory biomarkers such as mRNA of il-1β and il-6 expression in the liver in response to HFD. The in vitro study also confirmed that the addition of HSP-60 mimics in HepG2 cells led to upregulated expression level of HSP60 and restricted release of mt-dsRNA, as well as downregulated expression levels of TLR3, MDA5, and pIRF3. This study provides novel insight into a hepatoprotective effect, whereby HSP60 inhibits the release of dsRNA to repress the TLR3/MDA5/pIRF3 pathway in the context of NAFLD or hepatic inflammation. Therefore, HSP60 may serve as a possible therapeutic target for improving NAFLD.

The HSP Immune Network in Cancer

Heat shock proteins are molecular chaperones which support tumor development by regulating various cellular processes including unfolded protein response, mitochondrial bioenergetics, apoptosis, autophagy, necroptosis, lipid metabolism, angiogenesis, cancer cell stemness, epithelial-mesenchymal transition and tumor immunity. Apart from their intracellular activities, HSPs have also distinct extracellular functions. However, the role that HSP chaperones play in the regulation of immune responses inside and outside the cell is not yet clear. Herein, we explore the intracellular and extracellular immunologic functions of HSPs in cancer. A broader understanding of how HSPs modulate immune responses may provide critical insights for the development of effective immunotherapies.

Heat shock proteins with an emphasis on HSP 60

Heat shock phenomenon is a process by which cells express a set of proteins called heat shock proteins (HSPs) against heat stress. HSPs include several families depending upon the molecular weight of the respective protein. Among the different HSPs, The HSP60 is one of the main components representing the framework of chaperone system. HSP60 plays a myriad number of roles like chaperoning, thermotolerance, apoptosis, cancer, immunology and embryonic development. In this review we discussed briefly the general knowledge and focussed on HSP60 in terms of structure, regulation and function in various physiological and pathological conditions.

Cross-Linking Cellular Prion Protein Induces Neuronal Type 2-Like Hypersensitivity

Background

Previous reports identified proteins associated with ‘apoptosis’ following cross-linking PrP^C with motif-specific anti-PrP antibodies in vivo and in vitro. The molecular mechanisms underlying this IgG-mediated neurotoxicity and the role of the activated proteins in the apoptotic pathways leading to neuronal death has not been properly defined. Previous reports implicated a number of proteins, including apolipoprotein E, cytoplasmic phospholipase A2, prostaglandin and calpain with anti-PrP antibody-mediated ‘apoptosis’, however, these proteins are also known to play an important role in allergy. In this study, we investigated whether cross-linking PrP^C with anti-PrP antibodies stimulates a neuronal allergenic response.

Methods

Initially, we predicted the allergenicity of the epitope sequences associated with ‘neurotoxic’ anti-PrP antibodies using allergenicity prediction servers. We then investigated whether anti-PrP antibody treatment of mouse primary neurons (MPN), neuroblastoma cells (N2a) and microglia (N11) cell lines lead to a neuronal allergenic response.

Results

In-Silico studies showed that both tail- and globular-epitopes were allergenic. Specifically, binding regions that contain epitopes for previously reported ‘neurotoxic’ antibodies such as ICSM18 (146-159), ICSM35 (91-110), POM 1 (138-147) and POM 3 (95-100) lead to activation of allergenic related proteins. Following direct application of anti-PrP^C antibodies on N2a cells, we identified 4 neuronal allergenic-related proteins when compared with untreated cells. Furthermore, we identified 8 neuronal allergenic-related proteins following treatment of N11 cells with anti-PrP^C antibodies prior to co-culture with N2a cells when compared with untreated cells. Antibody treatment of MPN or MPN co-cultured with antibody-treated N11 led to identifying 10 and 7 allergenic-related proteins when compared with untreated cells. However, comparison with 3F4 antibody treatment revealed 5 and 4 allergenic-related proteins respectively. Of importance, we showed that the allergenic effects triggered by the anti-PrP antibodies were more potent when antibody-treated microglia were co-cultured with the neuroblastoma cell line. Finally, co-culture of N2a or MPN with N11-treated with anti-PrP antibodies resulted in significant accumulation of NO and IL6 but not TNF-α in the cell culture media supernatant.

Conclusions

This study showed for the first time that anti-PrP antibody binding to PrP^C triggers a neuronal hypersensitivity response and highlights the important role of microglia in triggering an IgG-mediated neuronal hypersensitivity response. Moreover, this study provides an important impetus for including allergenic assessment of therapeutic antibodies for neurodegenerative disorders to derive safe and targeted biotherapeutics.

High concentrations of environmental ammonia induced changes in large-scale loach (Paramisgurnus dabryanus) immunity

High concentrations of environmental ammonia can cause reduced immunity and death in fish, causing enormous economic losses. Air-breathing fish usually have a high ammonia tolerance and are very suitable for high-density fish farming. However, research on the effects of environmental ammonia on air-breathing fish immunity is lacking. Therefore, this study investigated the effects of environmental ammonia on the immunity of large-scale loach (Paramisgurnus dabryanus) by exposing fish to 30 mmol/L NH4Cl solution and subsequently analyzing the changes in serum and liver immune indicators, including total protein, albumin, globulin, immunoglobulin (Ig) M, lysozyme, complement component (C) 3 and C4, heat shock protein (HSP) 70, HSP90, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-12. Results revealed that ammonia exposure significantly affected the total protein, albumin, globulin, IgM, complement C3 and C4, HSP70, HSP90, and inflammatory cytokine contents in the body, indicating that ammonia exposure induced a significant immune response and lowered bodily immunity. However, most of the immune indicators significantly decreased in the later stages of the experiment, suggesting a weakened immune response, which may be due to the species-specific ammonia detoxification ability of large-scale loach that reduces ammonia toxicity in the body.

Oral Tolerance Induced by Heat Shock Protein 65-Producing Lactococcus lactis Mitigates Inflammation in Leishmania braziliensis Infection

Cutaneous leishmaniasis caused by L. braziliensis induces a pronounced Th1 inflammatory response characterized by IFN-γ production. Even in the absence of parasites, lesions result from a severe inflammatory response in which inflammatory cytokines play an important role. Different approaches have been used to evaluate the therapeutic potential of orally administrated heat shock proteins (Hsp). These proteins are evolutionarily preserved from bacteria to humans, highly expressed under inflammatory conditions and described as immunodominant antigens. Tolerance induced by the oral administration of Hsp65 is capable of suppressing inflammation and inducing differentiation in regulatory cells, and has been successfully demonstrated in several experimental models of autoimmune and inflammatory diseases. We initially administered recombinant Lactococcus lactis (L. lactis) prior to infection as a proof of concept, in order to verify its immunomodulatory potential in the inflammatory response arising from L. braziliensis. Using this experimental approach, we demonstrated that the oral administration of a recombinant L. lactis strain, which produces and secretes Hsp65 from Mycobacterium leprae directly into the gut, mitigated the effects of inflammation caused by L. braziliensis infection in association or not with PAM 3CSK4 (N-α-Palmitoyl-S-[2,3-bis(palmitoyloxy)-(2RS)-propyl]-L-cysteine, a TLR2 agonist). This was evidenced by the production of anti-inflammatory cytokines and the expansion of regulatory T cells in the draining lymph nodes of BALB/c mice. Our in vitro experimental results suggest that IL-10, TLR-2 and LAP are important immunomodulators in L. braziliensis infection. In addition, recombinant L. lactis administered 4 weeks after infection was observed to decrease lesion size, as well as the number of parasites, and produced a higher IL-10 production and decrease IFN-γ secretion. Together, these results indicate that Hsp65-producing L. lactis can be considered as an alternative candidate for treatment in both autoimmune diseases, as well as in chronic infections that cause inflammatory disease.

GATA-3 as a Potential Therapeutic Target for Insulin Resistance and Type 2 Diabetes Mellitus

Impaired adipogenesis plays an important role in the development of obesity-associated insulin resistance and type 2 diabetes as it leads to ectopic fat deposition. The anti-adipogenic transcription factor GATA-3 was identified as one of the potential molecular targets responsible for the impairment of adipogenesis. The expression of GATA-3 is higher in insulinresistant obese individuals compared to BMI-matched insulin-sensitive counterparts. Adipose tissue inflammation is a crucial mediator of this process. Hyperglycemia mediates the activation of the immune system, partially through upregulation of GATA- 3, causing exacerbation of the inflammatory state associated with obesity. This review discusses the evidence supporting the inhibition of GATA-3 as a useful therapeutic strategy in obesity-associated insulin resistance and type 2 diabetes, through up-regulation adipogenesis and amelioration of the immune response.

Mycobacterial Hsp65 antigen delivered by invasive Lactococcus lactis reduces intestinal inflammation and fibrosis in TNBS-induced chronic colitis model

Intestinal fibrosis associated with Crohn’s disease (CD), which a common and serious complication of inflammatory bowel diseases. In this context, heat shock proteins (HSPs) might serve as an alternative treatment because these antigens play important roles in the regulation of effector T cells. We thus evaluated the anti-inflammatory and antifibrotic capacities of an invasive and Hsp65-producing strain—Lactococcus lactis NCDO2118 FnBPA+ (pXYCYT:Hsp65)—in chronic intestinal inflammation to assess its potential as an alternative therapeutic strategy against fibrotic CD. Experimental colitis was induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS) in BALB/c mice, and the mice were treated orally with L. lactis NCDO2118 FnBPA+ (pXYCYT:Hsp65) via intragastric gavage. The oral administration of this strain significantly attenuated the severity of inflammation and intestinal fibrosis in mice (p < 0.05). These results are mainly justified by reductions in the levels of the pro-fibrotic cytokines IL-13 and TGF-β and increases in the concentration of the regulatory cytokine IL-10. The L. lactis NCDO2118 FnBPA+ (pXYCYT:Hsp65) strain contributed to reductions in the severity of inflammatory damage in chronic experimental CD, and these findings confirm the effectiveness of this new antifibrotic strategy based on the delivery of therapeutic proteins to inside cells of the host intestinal mucosa.

Heat shock protein 60 and cardiovascular diseases: An intricate love-hate story

Cardiovascular diseases (CVDs) are the result of complex pathophysiological processes in the tissues comprising the heart and blood vessels. Inflammation is the main culprit for the development of cardiovascular dysfunction, and it may be traced to cellular stress events including apoptosis, oxidative and shear stress, and cellular and humoral immune responses, all of which impair the system's structure and function. An intracellular chaperone, heat shock protein 60 (HSP60) is an intriguing example of a protein that may both be an ally and a foe for cardiovascular homeostasis; on one hand providing protection against cellular injury, and on the other triggering damaging responses through innate and adaptive immunity. In this review we will discuss the functions of HSP60 and its effects on cells and the immune system regulation, only to later address its implications in the development and progression of CVD. Lastly, we summarize the outcome of various studies targeting HSP60 as a potential therapeutic strategy for cardiovascular and other diseases.

Invasive Lactococcus lactis producing mycobacterial Hsp65 ameliorates intestinal inflammation in acute TNBS-induced colitis in mice by increasing the levels of the cytokine IL-10 and secretory IgA

AIMS

To investigate the anti-inflammatory activity of an invasive and Hp65-producing strain Lactococcus lactis NCDO2118 FnBPA+ (pXYCYT:Hsp65) in acute 2,4,6-trinitrobenzene sulphonic acid (TNBS)-induced colitis in mice as an innovative therapeutic strategy against Crohn's disease (CD).

METHODS AND RESULTS

The pXYCYT:Hsp65 plasmid was transformed into the L. lactis NCDO2118 FnBPA+ strain, resulting in the L. lactis NCDO2118 FnBPA+ (pXYCYT:Hsp65) strain. Then, the functionality of the strain was evaluated in vitro for Hsp65 production by Western blotting and for invasion into Caco-2 cells. The results demonstrated that the strain was able to produce Hsp65 and efficiently invade eukaryotic cells. Subsequently, in vivo, the anti-inflammatory capacity of the recombinant strain was evaluated in colitis induced with TNBS in BALB/c mice. Oral administration of the recombinant strain was able to attenuated the severity of colitis by mainly reducing IL-12 and IL-17 levels and increasing IL-10 and secretory immunoglobulin A levels.

CONCLUSIONS

The L. lactis NCDO2118 FnBPA+ (pXYCYT:Hsp65) strain contributed to a reduction in inflammatory damage in experimental CD.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study, which used L. lactis for the production and delivery of Hsp65, has scientific relevance because it shows the efficacy of this new strategy based on therapeutic protein delivery into mammalian enterocytes.

Innate Immune Sensing by Cells of the Adaptive Immune System

Sensing of microbes or of danger signals has mainly been attributed to myeloid innate immune cells. However, T and B cells also express functional pattern recognition receptors (PRRs). In these cells, PRRs mediate signaling cascades that result in different functions depending on the cell's activation and/or differentiation status, on the environment, and on the ligand/agonist. Some of these functions are beneficial for the host; however, some are detrimental and are exploited by pathogens to establish persistent infections. In this review, we summarize the available literature on innate immune sensing by cells of the adaptive immune system and discuss possible implications for chronic infections.

Ammonia exposure induced abnormal expression of cytokines and heat shock proteins via glucose metabolism disorders in chicken neutrophils

Ammonia (NH₃) is a highly irritant, alkaline gas. Atmospheric emission of NH₃ was recognized as an environmental challenge. As a global issue, the NH₃ emission survey with spatially detailed information demonstrated that the sources of atmospheric NH₃ include agriculture (livestock wastes, fertilizers) and some industrial activities. As an environmental pollution, excessive NH₃ exposure can induce many bird dysfunction. Neutrophils respond to multiple invading pathogens through different mechanisms. In order to investigate the effect of NH₃ exposure on broilers' neutrophil, 1-day-old broilers were treated with/without NH₃ for 28 days. We extracted neutrophils from peripheral blood of chicken with/without NH₃ exposure and subsequently stimulated with PMA. Changes of cytokines and inflammatory bodies, heat shock proteins (HSPs), and glucose metabolism of neutrophil were examined in both cases. We not only explored that the index associated with inflammation changed due to NH₃ exposure but also observed the status of neutrophils which was treated with PMA stimulation. After NH₃ exposure, IL-1β and IL-6 were significantly increased on broilers neutrophil. Inflammatory-related factors (NLRP3, ASC, and caspase-1) were significantly elevated. The mRNA expression of HSP70 and HSP90 was increased significantly. All glucose metabolism indicators were reduced. In summary, we concluded that NH₃ enhanced inflammation and disrupted glucose metabolism, and increased the expression of HSPs and inflammatory factors. In addition, the sensitivity of neutrophils to exogenous stimuli was diminished. This information can not only be used to evaluate the damage of NH₃-spiked neutrophils to chickens, but also provide clues for human health pathophysiology caused by excess NH₃, providing valuable information for NH₃ risk management.

Heat Shock Protein 60 in Obesity: Effect of Bariatric Surgery and its Relation to Inflammation and Cardiovascular Risk

OBJECTIVE

Heat shock protein 60 (Hsp60) is an adipokine, and its serum concentrations are higher in patients with obesity compared to lean patients. This study aimed to analyze the effect of bariatric surgery on circulating concentrations of Hsp60 in morbid obesity and their correlation with inflammation and metabolic and cardiovascular risk.

METHODS

Fifty-three females with morbid obesity undergoing bariatric surgery were enrolled. Serum parameters and anthropometric measures were obtained at baseline and 3 to 12 months post surgery.

RESULTS

During the 12-month observation period, Hsp60 decreased significantly from 31.6 ± 4.7 ng/mL at baseline to 22.3 ± 3.0 ng/mL (3 months), 26.5 ± 5.5 (6 months), and 21.1 ± 3.3 ng/mL (12 months). Preoperatively, Hsp60 concentrations correlated positively with total cholesterol, low-density lipoprotein cholesterol, and apolipoprotein B (ApoB) and negatively with adiponectin. At the end of the observation period, serum Hsp60 positively correlated with triglycerides, ApoB, HbA_1c , and C-reactive protein (CRP). Patients in the highest quartile of serum Hsp60 were characterized by significantly elevated CRP and interleukin 6 independently of BMI, glycemia, and insulinemia. At baseline and 12 months after surgery, Hsp60 positively correlated with the ApoB/ApoA1 ratio and the cholesterol/high-density lipoprotein cholesterol ratio.

CONCLUSIONS

Hsp60 concentrations are elevated in morbid obesity and decreased after surgery-induced weight loss. Their correlation with inflammatory markers and cardiovascular risk might link obesity and cardiovascular disease.

Heat shock proteins and kidney disease: perspectives of HSP therapy

Heat shock proteins (HSPs) mediate a diverse range of cellular functions, prominently including folding and regulatory processes of cellular repair. A major property of these remarkable proteins, dependent on intracellular or extracellular location, is their capacity for immunoregulation that optimizes immune activity while avoiding hyperactivated inflammation. In this review, recent investigations are described, which examine roles of HSPs in protection of kidney tissue from various traumatic influences and demonstrate their potential for clinical management of nephritic disease. The HSP70 class is particularly attractive in this respect due to its multiple protective effects. The review also summarizes current understanding of HSP bioactivity in the pathophysiology of various kidney diseases, including acute kidney injury, diabetic nephropathy, chronic glomerulonephritis, and lupus nephritis-along with other promising strategies for their remediation, such as DNA vaccination.

Biotechnology approaches to produce potent, self-adjuvanting antigen-adjuvant fusion protein subunit vaccines

Traditional vaccination approaches (e.g. live attenuated or killed microorganisms) are among the most effective means to prevent the spread of infectious diseases. These approaches, nevertheless, have failed to yield successful vaccines against many important pathogens. To overcome this problem, methods have been developed to identify microbial components, against which protective immune responses can be elicited. Subunit antigens identified by these approaches enable the production of defined vaccines, with improved safety profiles. However, they are generally poorly immunogenic, necessitating their administration with potent immunostimulatory adjuvants. Since few safe and effective adjuvants are currently used in vaccines approved for human use, with those available displaying poor potency, or an inability to stimulate the types of immune responses required for vaccines against specific diseases (e.g. cytotoxic lymphocytes (CTLs) to treat cancers), the development of new vaccines will be aided by the availability of characterized platforms of new adjuvants, improving our capacity to rationally select adjuvants for different applications. One such approach, involves the addition of microbial components (pathogen-associated molecular patterns; PAMPs), that can stimulate strong immune responses, into subunit vaccine formulations. The conjugation of PAMPs to subunit antigens provides a means to greatly increase vaccine potency, by targeting immunostimulation and antigen to the same antigen presenting cell. Thus, methods that enable the efficient, and inexpensive production of antigen-adjuvant fusions represent an exciting mean to improve immunity towards subunit antigens. Herein we review four protein-based adjuvants (flagellin, bacterial lipoproteins, the extra domain A of fibronectin (EDA), and heat shock proteins (Hsps)), which can be genetically fused to antigens to enable recombinant production of antigen-adjuvant fusion proteins, with a focus on their mechanisms of action, structural or sequence requirements for activity, sequence modifications to enhance their activity or simplify production, adverse effects, and examples of vaccines in preclinical or human clinical trials.

Arsenic Trioxide Exposure Induces Heat Shock Protein Responses in Cock Livers

Arsenic is a trace element widely found in nature, and there are several forms of arsenic, including the most toxic form of trivalent arsenic. Arsenic trioxide (As2O3) is widespread in nature and tends to accumulate in animals and humans, thus causing great harm. Although the important role of heat shock proteins (HSPs) has been demonstrated in many types of mammals exposed to As2O3, the function of these proteins in poultry, especially in cocks, remains unclear. In this study, we used experimental animals (male chickens), which were fed a diet including 0, 7.5, 15, and 30 mg kg(-1) As2O3, respectively, in the control, low, middle, and high groups. The livers were collected after the cocks were treated with arsenic for 30, 60, and 90 days. We detected HSP27, HSP60, HSP70, and HSP90 levels in the livers of the cocks by real-time PCR and HSP60 and HSP70 levels by Western blot. The results showed that the messenger RNA and protein expression of HSPs exposed to As2O3 had obviously increased. These results demonstrated that arsenic toxicity affected the expression of HSP levels in cock livers.

Intrathecal heat shock protein 60 mediates neurodegeneration and demyelination in the CNS through a TLR4- and MyD88-dependent pathway

Background

Toll-like receptors (TLR) constitute a highly conserved class of receptors through which the innate immune system responds to both pathogen- and host-derived factors. Although TLRs are involved in a wide range of central nervous system (CNS) disorders including neurodegenerative diseases, the molecular events leading from CNS injury to activation of these innate immune receptors remain elusive. The stress protein heat shock protein 60 (HSP60) released from injured cells is considered an endogenous danger signal of the immune system. In this context, the main objective of the present study was to investigate the impact of extracellular HSP60 on the brain in vivo.

Results

We show here that HSP60 injected intrathecally causes neuronal and oligodendrocyte injury in the CNS in vivo through TLR4-dependent signaling. Intrathecal HSP60 results in neuronal cell death, axonal injury, loss of oligodendrocytes, and demyelination in the cerebral cortex of wild-type mice. In contrast both mice lacking TLR4 and the TLR adaptor molecule MyD88 are protected against deleterious effects induced by HSP60. In contrast to the exogenous TLR4 ligand, lipopolysaccharide, intrathecal HSP60 does not induce such a considerable inflammatory response in the brain. In the CNS, endogenous HSP60 is predominantly expressed in neurons and released during brain injury, since the cerebrospinal fluid (CSF) from animals of a mouse stroke model contains elevated levels of this stress protein compared to the CSF of sham-operated mice.

Conclusions

Our data show a direct toxic effect of HSP60 towards neurons and oligodendrocytes in the CNS. The fact that these harmful effects involve TLR4 and MyD88 confirms a molecular pathway mediated by the release of endogenous TLR ligands from injured CNS cells common to many forms of brain diseases that bi-directionally links CNS injury and activation of the innate immune system to neurodegeneration and demyelination in vivo.

Electronic supplementary material

The online version of this article (doi:10.1186/s13024-015-0003-1) contains supplementary material, which is available to authorized users.

IL-10 is significantly involved in HSP70-regulation of experimental subretinal fibrosis

Subretinal fibrosis is directly related to severe visual loss, especially if occurs in the macula, and is frequently observed in advanced age-related macular degeneration and other refractory eye disorders such as diabetic retinopathy and uveitis. In this study, we analyzed the immunosuppressive mechanism of subretinal fibrosis using the novel animal model recently demonstrated. Both TLR2 and TLR4 deficient mice showed significant enlargement of subretinal fibrotic area as compared with wild-type mice. A single intraocular administration of heat shock protein 70 (HSP70), which is an endogenous ligand for TLR2 and TLR4, inhibited subretinal fibrosis in wild-type mice but not in TLR2 and TLR4-deficient mice. Additionally, HSP70 induced IL-10 production in eyes from wild-type mice but was impaired in both TLR2- and TLR4-deficient mice, indicating that HSP70-TLR2/TLR4 axis plays an immunomodulatory role in subretinal fibrosis. Thus, these results suggest that HSP70-TLR2/TLR4 axis is a new therapeutic target for subretinal fibrosis due to prognostic CNV.

Cellular stress response and innate immune signaling: integrating pathways in host defense and inflammation

Extensive research in the past decade has identified innate immune recognition receptors and intracellular signaling pathways that culminate in inflammatory responses. Besides its role in cytoprotection, the importance of cell stress in inflammation and host defense against pathogens is emerging. Recent studies have shown that proteins in cellular stress responses, including the heat shock response, ER stress response, and DNA damage response, interact with and regulate signaling intermediates involved in the activation of innate and adaptive immune responses. The effect of such regulation by cell stress proteins may dictate the inflammatory profile of the immune response during infection and disease. In this review, we describe the regulation of innate immune cell activation by cell stress pathways, present detailed descriptions of the types of stress response proteins and their crosstalk with immune signaling intermediates that are essential in host defense, and illustrate the relevance of these interactions in diseases characteristic of aberrant immune responses, such as chronic inflammatory diseases, autoimmune disorders, and cancer. Understanding the crosstalk between cellular stress proteins and immune signaling may have translational implications for designing more effective regimens to treat immune disorders.

Signaling via TLR2 and TLR4 Directly Down-Regulates T Cell Effector Functions: The Regulatory Face of Danger Signals

Toll-like receptors (TLRs) are widely expressed and play an essential role in the activation of innate immune cells. However, certain TLRs are also expressed on T cells, and TLR ligands can directly modulate T cell functions. Here, we discuss findings indicating that T cells directly respond to Heat Shock Protein (HSP) 60, a self molecule, or to the HSP60-derived peptide, p277, via a TLR2-dependent mechanism. HSP60 has been considered to be a “danger signal” for the immune system because of its ability to induce pro-inflammatory phenotypes in innate immune cells – in this case via TLR4 activation; nevertheless, TLR2 engagement by HSP60 on T cells can lead to resolution of inflammation by up-regulating the suppression function of regulatory T cells and shifting the resulting cytokine secretion balance toward a Th2 phenotype. Moreover, T cell TLR4 engagement by LPS leads to up-regulation of suppressor of cytokine signaling 3 expression and consequently down-regulates T cell chemotaxis. Thus, TLR2 and TLR4 activation can contribute to both induction and termination of effector immune responses by controlling the activities of both innate and adaptive immune cells.

Heat shock protein profiles on the protein and gene expression levels in olive flounder kidney infected with Streptococcus parauberis

Heat shock proteins (HSPs) have been observed in cells exposed to a variety of stresses, including infectious pathogens. This study used a label-free, quantitative proteomic approach and transcriptional gene expression analysis to investigate infection-related HSP proteins and their encoding genes in whole kidneys from olive flounder (Paralichthys olivaceus). During Streptococcus parauberis infection in the flounder, the genes encoding Hsp10, Hsp40A4, Hsp40B6, Hsp40B11, Hsp60, Hsp70, glucose regulated protein 78 (Grp78), Hsp90α, Hsp90β and Grp94 were induced, and the protein levels of Hsp60, Hsp70, Hsp90α, Hsp90β and Grp94 were differentially regulated over time. Subsequent results also revealed that Hsp60, Hsp70, Hsp90α, Hsp90β and Grp94 appear to be the dominant and critical HSPs in olive flounder during bacterial infection. This is the first estimation of the differential involvement of HSPs in the immune response of olive flounder exposed to bacterial infection.

HSP70 enhances immunosuppressive function of CD4(+)CD25(+)FoxP3(+) T regulatory cells and cytotoxicity in CD4(+)CD25(-) T cells

Human CD4⁺CD25⁺FoxP3⁺ T regulatory cells (Tregs) control effector T cells and play a central role in peripheral tolerance and immune homeostasis. Heat shock protein 70 (HSP70) is a major immunomodulatory molecule, but its effect on the functions of Tregs is not well understood. To investigate target-dependent and –independent Treg functions, we studied cytokine expression, regulation of proliferation and cytotoxicity after exposure of Tregs to HSP70. HSP70-treated Tregs significantly inhibited proliferation of CD4⁺CD25⁻ target cells and downregulated the secretion of the proinflammatory cytokines IFN-γ and TNF-α. By contrast, HSP70 increased the secretion of Treg suppressor cytokines IL-10 and TGF-β. Treatment with HSP70 enhanced the cytotoxic properties of Tregs only to a minor extent (4-fold), but led to stronger responses in CD4⁺CD25⁻ cells (42-fold). HSP70-induced modulation of T-cell responses was further enhanced by combined treatment with HSP70 plus IL-2. Treatment of Tregs with HSP70 led to phosphorylation of PI3K/AKT and the MAPKs JNK and p38, but not that of ERK1/2. Exposure of Tregs to specific inhibitors of PI3K/AKT and the MAPKs JNK and p38 reduced the immunosuppressive function of HSP70-treated Tregs as indicated by the modified secretion of specific target cell (IFN-γ, TNF-α) and suppressor cytokines (IL-10, TGF-β). Taken together, the data show that HSP70 enhances the suppressive capacity of Tregs to neutralize target immune cells. Thus HSP70-enhanced suppression of Tregs may prevent exaggerated immune responses and may play a major role in maintaining immune homeostasis.

Hsp65-producing Lactococcus lactis prevents experimental autoimmune encephalomyelitis in mice by inducing CD4+LAP+ regulatory T cells

Heat shock proteins (Hsps) participate in the cellular response to stress and they are hiperexpressed in inflammatory conditions. They are also known to play a major role in immune modulation, controlling, for instance, autoimmune responses. In this study, we showed that oral administration of a recombinant Lactococcus lactis strain that produces and releases LPS-free Hsp65 prevented the development of experimental autoimmune encephalomyelitis (EAE) in C57BL/6 mice. This was confirmed by the reduced inflammatory cell infiltrate and absence of injury signs in the spinal cord. The effect was associated with reduced IL-17 and increased IL-10 production in mesenteric lymph node and spleen cell cultures. Hsp65-producing-L. lactis-fed mice had a remarkable increase in the number of natural and inducible CD4+Foxp3+ regulatory T (Treg) cells and CD4+LAP+ (Latency-associated peptide) Tregs - which express the membrane-bound TGF-β - in spleen, inguinal and mesenteric lymph nodes as well as in spinal cord. Moreover, many Tregs co-expressed Foxp3 and LAP. In vivo depletion of LAP+ cells abrogated the effect of Hsp65-producing L. lactis in EAE prevention and worsened disease in medium-fed mice. Thus, Hsp65-L.lactis seems to boost this critical regulatory circuit involved in controlling EAE development in mice.

Recombinant Wolbachia heat shock protein 60 (HSP60) mediated immune responses in patients with lymphatic filariasis

Wolbachia, an endosymbiont present in filarial nematodes, have been implicated in a variety of roles, including the worm development and survival. Elucidation of the role of Wolbachia in filarial nematode biology and pathogenesis has become the focus of many studies and its contribution to parasite survival or immune response is still unclear. Recombinant Wolbachia HSP60 decreases T cell activation and lymphoproliferation in filarial infected people compared to endemic controls as observed by the assessment of T cell activation markers and cytokine responses in the peripheral blood mononuclear cells. Reduced T cell activation may be linked to T regulatory cell activity since it is associated with increased expression of CTLA4 and CD25 on CD4(+) T cells in filarial infected group upon stimulation with recombinant Wolbachia HSP60. In addition, elevated interleukin-10 and TGF-β cytokines corroborate the reduced CD4(+) T cell activation and interferon-γ observed upon recombinant Wolbachia HSP60 stimulation in filarial patients. Hence, these findings indicate that Wolbachia HSP60 may also contribute to the immune modulation seen in filarial patients.

Molecular cloning, characterization and expression patterns of HSP60 in the grass carp (Ctenopharyngodon idella)

HSP60 is a highly immunogenic molecule, which is able to activate a large number of T cell types and is implicated in a variety of autoimmune diseases. The grass carp (Ctenopharyngodon idella), a freshwater fish species of the family Cyprinidae, accounts for the third biggest value (USD 4.8 billion) at single species level of major cultured fish species in the world. Here, we isolated and characterized the HSP60 cDNA from grass carp (designated as CiHSP60). Its cDNA was 2434 bp in length and encoded a putative protein of 575 amino acids. BLAST analysis revealed that the CiHSP60 gene shared a high similarity with other known HSP60 sequences. CiHSP60 contained all three classical HSP60 family signatures. The mRNA of CiHSP60 was constitutively expressed in all tested tissues of untreated grass carp, including brain, muscle, trunk kidney, liver, head kidney, skin, spleen, heart, gill, intestine, and fin, with the highest expression level in the blood. CiHSP60 transcript was present in unfertilized eggs, which suggests that CiHSP60 transcription is maternally inherited. Fluorescent real-time quantitative RT-PCR was used to examine the expression of the CiHSP60 gene in grass carp after the challenge with the bacterium Aeromonas hydrophila. A clear time-dependent expression pattern of CiHSP60 was found after the bacterial challenge, and the mRNA expression reached a maximum level at three days post challenge, and returned to control levels after seven days. The upregulated mRNA expression of CiHSP60 in grass carp after bacterial challenge indicates that the HSP60 gene is inducible and involved in immune responses. These results suggest that CiHSP60 plays an important role in A. hydrophila-related diseases and in early embryonic development stages in grass carp.

A Mycobacterium leprae Hsp65 mutant as a candidate for mitigating lupus aggravation in mice

Hsp60 is an abundant and highly conserved family of intracellular molecules. Increased levels of this family of proteins have been observed in the extracellular compartment in chronic inflammation. Administration of M. leprae Hsp65 [WT] in [NZBxNZW]F₁ mice accelerates the Systemic Lupus Erythematosus [SLE] progression whereas the point mutated K⁴⁰⁹A Hsp65 protein delays the disease. Here, the biological effects of M. leprae Hsp65 Leader pep and K⁴⁰⁹A pep synthetic peptides, which cover residues 352–371, are presented. Peptides had immunomodulatory effects similar to that observed with their respective proteins on survival and the combined administration of K⁴⁰⁹A+Leader pep or K⁴⁰⁹A pep+WT showed that the mutant forms were able to inhibit the deleterious effect of WT on mortality, indicating the neutralizing potential of the mutant molecules in SLE progression. Molecular modeling showed that replacing Lysine by Alanine affects the electrostatic potential of the 352–371 region. The number of interactions observed for WT is much higher than for Hsp65 K⁴⁰⁹A and mouse Hsp60. The immunomodulatory effects of the point-mutated protein and peptide occurred regardless of the catalytic activity. These findings may be related to the lack of effect on survival when F₁ mice were inoculated with Hsp60 or K⁴⁰⁹A pep. Our findings indicate the use of point-mutated Hsp65 molecules, such as the K⁴⁰⁹A protein and its corresponding peptide, that may minimize or delay the onset of SLE, representing a new approach to the treatment of autoimmune diseases.

Serum heat shock protein 60 can predict remission of flare-up in juvenile idiopathic arthritis

Heat shock protein (Hsp) 60 has been implicated in the pathogenesis of various inflammatory and autoimmune diseases. This study aimed to investigate synovial fluid and serum concentrations of Hsp60 and anti-Hsp60 and their relationship with juvenile idiopathic arthritis (JIA). Forty-eight patients with JIA, including 22 oligo-articular, 19 poly-articular, and 7 systemic diseases, and 33 normal controls were enrolled in this study. Synovial fluid and serum Hsp60 and anti-Hsp60 concentrations were measured via ELISA. Serum concentrations of Hsp60 of active and inactive oligo- and poly-articular JIA were significantly higher than those of normal controls. Serum concentration of anti-Hsp60 in active oligo-articular JIA was higher than that of normal controls (49.25 vs. 35.76 ng/mL, p = 0.059). Similarly, serum concentration of anti-Hsp60 in active poly-articular JIA was significantly higher than that of inactive samples (65.05 vs. 26.54 ng/mL, p = 0.008). In addition, serum concentration of Hsp60 correlated with the time required for remission from flare-ups in patients with JIA. Serum concentration of Hsp60 correlated well with time required for remission from flare-ups in patients with JIA, representing a potential disease marker to monitor disease activity.

The HSP60 immune system network

Heat shock proteins (HSPs) were initially discovered as participants in the cellular response to stress. It is now clear, however, that self and microbial HSPs also play an important role in the control of the immune response. Here, we focus on HSP60 and its interactions with both the innate and adaptive immune system in mammals. We also consider that circulating HSP60 and the quantities and specificities of serum antibodies to HSP60 provide a biomarker to monitor the immune status of the individual. Thus, the dual role of HSP60 as an immune modulator and a biomarker, provides an opportunity to modulate immunity for therapeutic purposes, and to monitor the immune response in health and disease.

All-trans retinoic acid ameliorates trinitrobenzene sulfonic acid-induced colitis by shifting Th1 to Th2 profile

Inflammatory bowel disease is characterized with uncontrolled immune response in inflamed mucosa, with dominance of Th1 cells. Recently, all-trans retinoic acid has been shown that can lead T-cell response by suppressing Th17 development via retinoic acid receptor (RAR), but it is still unknown whether all-trans retinoic acid can modulate Th1 response of inflammatory bowel disease. In the experiment, we investigated the effect of all-trans retinoic acid on trinitrobenzene sulfonic acid (TNBS)-induced murine colitis, and the possible mechanism. Mice were intraperitoneally treated daily with all-trans retinoic acid (the agonist of RAR-alpha) or LE135 (the antagonist of RAR-alpha) or medium, and sacrificed 6 days later. Colon was collected for histological analysis and myeloperoxidase (MPO) activity measurement. Lamina propria mononuclear cells (LPMCs) were isolated, cultured, and assayed for the expressions of T-bet and GATA-3 by the use of Western blot and for cytokine levels by the use of ELISA. All-trans retinoic acid treatment inhibited inflammatory responses as shown by lower histological inflammatory scores and MPO activity, compared with LE135 and medium groups. Furthermore, in LPMCs culture supernatants, the levels of Th1 cytokines (INF-gamma, IL-12, and TNF-alpha) were decreased while those of Th2 cytokines (IL-4 and IL-10) were increased significantly in all-trans retinoic acid-treated mice. In addition, T-bet expression in LPMCs was inhibited and GATA-3 expression was up-regulated in all-trans retinoic acidtreated mice. On the contrary, LE135 showed the reverse effects in colon inflammation and cytokine profile. By shifting Th1 to Th2 profile in inflamed mucosa, all-trans retinoic acid down-regulates inflammatory response and ameliorates acute TNBS-induced colitis, which suggests the ligand of RAR-alpha-based pharmaceutical strategies for managing inflammatory bowel disease.

Protein expression changes in human monocytic THP-1 cells treated with lipoteichoic acid from Lactobacillus plantarum and Staphylococcus aureus

Lipoteichoic acid (LTA) from Staphylococcus aureus (aLTA) and from Lactobacillus plantarum LTA (pLTA) are both recognized by Toll-like receptor 2 (TLR2), but cause different stimulatory effects on the innate immune and inflammatory responses, and their underlying cellular mechanisms are unknown. In this study, comparative proteome analysis was performed using two-dimensional gel electrophoresis and mass spectrometry on protein extracts from human monocyte THP-1 cells stimulated with either aLTA or pLTA. Differentially expressed proteins might be involved in innate immunity and inflammation. Cells treated with aLTA and with pLTA showed different protein expression profiles. Of 60 identified proteins, 10 were present only in treated cells (8 in aLTA-treated only, and 2 in pLTA-treated only), 1 protein (IMPDH2) was suppressed by pLTA, and 49 were up- or down-regulated more than three-fold by aLTA- or pLTA- stimulation. Several proteins involved in immunity or inflammation, antioxidation, or RNA processing were significantly changed in expression by aLTA- or pLTA-stimulation, including cyclophilin A, HLA-B27, D-dopachrome tautomerase, Mn- SOD, hnRNP-C, PSF and KSRP. These data demonstrated that aLTA and pLTA had different effects on the protein profile of THP-1 cells. Comparison of the proteome alterations will provide candidate biomarkers for further investigation of the immunomodulatory effects of aLTA and pLTA, and the involvement of aLTA in the pathogenesis of Staphylococcus aureus sepsis.

Possible Association between Th1 Immune Polarization and Epithelial Permeability with Toll-Like Receptors 2 Dysfunction in the Pathogenesis of the Recurrent Aphthous Ulceration

Recurrent Aphthous Ulceration (RAU) is a chronic oral inflammatory disease that affects approximately 25% of the general population. The etiology of the disease is unknown; however, factors that favor the onset of RAU have been correlated with a Th1 immune polarization, while factors that reduce RAU episodes have been associated with down regulation of immune reaction or stimulation of the peripheral tolerance. In this context, the integrity of the epithelial barrier is also fundamental for the prevention of the disease and conditions that augment its permeability or produce disruption are considered potential triggers. The key factor responsible for increased susceptibility is unclear, though a deficiency of Toll-like receptor (TLR) activity seems to be a good candidate. TLRs are a group of membrane proteins that recognize conserved molecules derived from bacterial, virus, fungal, or host tissues. Particularly, the TLR2 is involved in both immune regulation and control of epithelial barrier integrity. Thus, based on literature review, we showed evidences that correlate the TLR2 dysfunction and the diverse predisposing factors with the elements considered critical for disease pathogenesis: the Th1 immune reaction and the increased epithelial permeability.

Caught with their PAMPs down? The extracellular signalling actions of molecular chaperones are not due to microbial contaminants

In recent years, it has been hypothesised that a new signalling system may exist in vertebrates in which secreted molecular chaperones form a dynamic continuum between the cellular stress response and corresponding homeostatic physiological mechanisms. This hypothesis seems to be supported by the finding that many molecular chaperones are released from cells and act as extracellular signals for a range of cells. However, this nascent field of biological research seems to suffer from an excessive criticism that the biological activities of molecular chaperones are due to undefined components of the microbial expression hosts used to generate recombinant versions of these proteins. In this article, a number of the proponents of the cell signalling actions of molecular chaperones take this criticism head-on. They show that sufficient evidence exists to support fully the hypothesis that molecular chaperones have cell-cell signalling actions that are likely to be part of the homeostatic mechanism of the vertebrate.

The heat shock protein profile in children with chronic kidney disease

OBJECTIVES

Chronic kidney disease (CKD) due to inflammation, lipid disorders, and endothelial dysfunction predisposes to accelerated atherosclerosis. Elevated levels of heat shock proteins (HSPs) and antibodies against them have been described in adults with atherosclerotic lesions and cardiovascular events. However, there are no investigations of these variables in children with CKD treated conservatively or on peritoneal dialysis. Therefore, we decided to evaluate the profile of HSPs and their potential role as markers of atherosclerosis in these groups of patients.

METHODS

The study group consisted of 37 children with CKD treated conservatively and 19 children and young adults on automated peritoneal dialysis (APD). The control group comprised 15 age-matched subjects with normal kidney function. HSP-60, HSP-70, HSP-90alpha, anti-HSP-60, anti-HSP-70, sE-selectin, and interleukin (IL)-4 serum concentrations were assessed by ELISA; high-sensitivity C-reactive protein (hs-CRP) serum levels were assessed by nephelometry. Serum lipid profiles (total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol, triglycerides) were also estimated.

RESULTS

HSP-90alpha, anti-HSP-60, and sE-selectin concentrations in the CKD and APD patients were higher than in the controls and were lower in the predialysis subjects than in the children on dialysis. Median values of anti-HSP-70 were higher in the CKD patients than in the control group. Levels of IL-4 were increased in all patients versus controls. Median values of HSP-60 were decreased in the CKD and APD children versus controls. HSP-70 and hs-CRP concentrations were comparable in all groups.

CONCLUSIONS

The altered HSP and anti-HSP concentrations may imply that the response to stress conditions in the course of CKD is disturbed in children; APD does not aggravate that dysfunction in a significant way. Relationships between HSPs, lipid profile, and markers of inflammation suggest a possible role of the selected HSPs as markers of atherosclerosis in children with CKD.

Alveolar macrophages in allergic asthma: an expression signature characterized by heat shock protein pathways

The implication of alveolar macrophages (AM) in asthma, a T_h2 disease, has not been well characterized. Thus, the goal of this study is to better characterize AM phenotype of allergic asthmatic compared with normal subjects using genomic expression analyses. Microarray analyses were performed with AM isolated from bronchoalveolar lavage. Robust multiarray analysis (RMA) normalization and Smyth's moderated t test were used to select differentially expressed genes. Fifty differentially expressed genes were identified. Nineteen have been classified in categories linked to stress or immune responses and among them; nine are part of the heat shock protein (HSP) family. Difference of expression for three (HSPD1, PRNP, SERPINH1) of the five selected genes were validated using real-time reverse transcription–polymerase chain reaction. Enzyme-linked immunosorbent assay was used to measure the protein level of heat shock protein 60 (HSP60), the protein encoded by HSPD1, and showed difference in AM protein level between allergic asthmatic and control subjects. In summary, this study suggests that HSP gene family, particularly HSP60, is involved in AM functions in a context of allergic asthma. These results also support the involvement of AM immune functions in the development of an allergic asthmatic response.

TLR triggering on tolerogenic dendritic cells results in TLR2 up-regulation and a reduced proinflammatory immune program

Tolerogenic dendritic cells (TDC) offer a promising therapeutic potential to ameliorate autoimmune diseases. Reported to inhibit adaptive immune responses, little is known about their innate immunity receptor repertoire. In this study, we compared three types of human TDC (IL-10-DC, dexamethasone (DX)-DC, and 1,25(OH)(2)D(3)-DC) by their TLR expression and response to a set of TLR ligands. TDC are endowed with the same TLR set as standard monocyte-derived dendritic cells but respond differentially to the TLR stimuli Pam3CSK4, polyinosinic-polycytidylic acid, LPS, and flagellin. TDC expressed low or no IL-12-related cytokines and remarkably elevated IL-10 levels. Interestingly, only TDC up-regulated the expression of TLR2 upon stimulation. This boosted the tolerogenic potential of these cells, because IL-10 production was up-regulated in TLR2-stimulated, LPS-primed DX-DC, whereas IL-12 and TNF-alpha secretion remained low. When comparing the TDC subsets, DX-DC and 1,25(OH)(2)D(3)-DC up-regulated TLR2 irrespective of the TLR triggered, whereas in IL-10-DC this effect was only mediated by LPS. Likewise, DX-DC and 1,25(OH)(2)D(3)-DC exhibited impaired ability to mature, reduced allostimulatory properties, and hampered capacity to induce Th1 differentiation. Therefore, both DX-DC and 1,25(OH)(2)D(3)-DC display the strongest tolerogenic and anti-inflammatory features and might be most suitable tools for the treatment of autoimmune diseases.

Heat shock protein 60, via MyD88 innate signaling, protects B cells from apoptosis, spontaneous and induced

We recently reported that heat shock protein 60 (HSP60) via TLR4 signaling activates B cells and induces them to proliferate and secrete IL-10. We now report that HSP60 inhibits mouse B cell apoptosis, spontaneous or induced by dexamethasone or anti-IgM activation. Unlike HSP60 enhancement of B cell proliferation and IL-10 secretion, TLR4 signaling was not required for the inhibition of apoptosis by HSP60; nevertheless, MyD88 was essential. Inhibition of apoptosis by HSP60 was associated with up-regulation of the antiapoptotic molecules Bcl-2, Bcl-x(L), and survivin, maintenance of the mitochondrial transmembrane potential, and inhibition of caspase-3 activation. Moreover, B cells incubated with HSP60 manifested prolonged survival following transfer into recipient mice. These results extend the varied role of HSP60 in the innate regulation of the adaptive immune response.

Identification of GATA3 binding sites in Jurkat cells

Determining binding sites of transcription factors is important for understanding the transcriptional control of target genes. Although a transcription factor GATA3 plays a pivotal role in Th2 lymphocyte development, its physiological role is not clearly defined because the target genes remain largely unknown. In this study, we modified chromatin immunoprecipitation (ChIP), and isolated 121 GATA3 binding sites and 83 different annotated target genes. Re-ChIP analysis using anti-GATA3 and anti-RNA polymerase II mAbs and chromosome conformation capture assay demonstrate that GATA3-bound fragments interact with basal transcriptional units of target genes. GATA3 regulation of target genes under the control of binding fragments was confirmed by reporter assay and quantification of target gene mRNA expression in the presence of GATA inhibitor or short interfering RNA against GATA3. These data demonstrate that GATA3 binds to regulatory elements and controls target gene expression through physical interaction with core promoter regions.

Advances in Type 1 diabetes therapeutics: immunomodulation and beta-cell salvage

Refinements in our understanding of the pathogenic mechanisms of Type 1 diabetes from studies of animal models and clinical observation have led to new clinical trials to prevent disease progression and restore the loss of beta-cells that defines the disease. Antigen-specific agents have shown initial promise and non-antigen-specific agents now have improved safety compared with older agents. In addition, preclinical studies with other agents have shown efficacy. Ultimately, a combination of immunologic and cellular therapies may be needed to restore metabolic control. Agents that augment recovery of dysfunctional beta-cells, and other compounds that may be able to induce beta-cell replication, are logical additions once immune tolerance is achieved.