Hepatic extracellular ATP/adenosine dynamics in zebrafish models of alcoholic and metabolic steatotic liver disease.

Steatotic liver disease (SLD) is a burgeoning health problem predominantly associated with excessive alcohol consumption, which causes alcohol-related liver disease (ALD), and high caloric intake, which results in metabolic dysfunction-associated SLD (MASLD). The pathogenesis of ALD and MASLD, which can progress from steatohepatitis to more severe conditions such as liver fibrosis, cirrhosis, and hepatocellular carcinoma, is complicated by several factors. Recently, extracellular ATP and adenosine (Ado), as damage-associated molecular patterns, were reported to promote inflammation and liver fibrosis, contributing to SLD pathogenesis. Here, we explored the in vivo dynamics of hepatic extracellular ATP and Ado during the progression of steatohepatitis using a genetically encoded GPCR-activation-based sensor (GRAB) in zebrafish models. We established hepatocyte-specific GRABATP and GRABAdo in zebrafish and investigated the changes in in vivo hepatic extracellular ATP and Ado levels under ALD or MASLD conditions. Disease-specific changes in hepatocyte extracellular ATP and Ado levels were observed, clearly indicating a correlation between hepatocyte extracellular ATP/Ado dynamics and disease progression. Furthermore, clodronate, a vesicular nucleotide transporter inhibitor, alleviated the MASLD phenotype by reducing the hepatic extracellular ATP and Ado content. These findings provide deep insights into extracellular ATP/Ado dynamics in disease progression, suggesting therapeutic potential for ALD and MASLD.

Behavioral and neurotransmitter changes on antiepileptic drugs treatment in the zebrafish pentylenetetrazol-induced seizure model.

Epilepsy, a recurrent neurological disorder involving abnormal neurotransmitter kinetics in the brain, has emerged as a global health concern. The mechanism of epileptic seizures is thought to involve a relative imbalance between excitatory and inhibitory neurotransmitters. Despite the recent advances in clinical and basic research on the pathogenesis of epilepsy, the complex relationship between the neurotransmitter changes and behavior with and without antiepileptic drugs (AEDs) during seizures remains unclear. To investigate the effects of AEDs such as levetiracetam (LEV), carbamazepine (CBZ), and fenfluramine (FFR) on key neurotransmitters in the pentylenetetrazol (PTZ)-induced seizures in adult zebrafish, we examined the changes in glutamic acid, gamma-aminobutyric acid (GABA), serotonin (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), choline, acetylcholine, norepinephrine, dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), and adenosine. In this study, we observed that 5-HT and DA levels in the brain increased immediately after PTZ-induced seizures. Behavioral tests clearly showed that all of these AEDs suppressed the PTZ-induced seizures. Upon treatment of PTZ-induced seizures with these AEDs, CBZ decreased the glutamic acid and FFR increased the GABA levels; however, no neurotransmitter changes were observed in the brain after LEV administration. Thus, we demonstrated a series of neurotransmitter changes linked to behavioral changes during PTZ-induced epileptic seizures when LEV, CBZ, or FFR were administered. These findings will lead to a more detailed understanding of the pathogenesis of epilepsy associated with behavioral and neurotransmitter changes under AED treatment.

A pH imbalance is linked to autophagic dysregulation of inner ear hair cells in Atp6v1ba-deficient zebrafish.

V-ATPase is an ATP hydrolysis-driven proton pump involved in the acidification of intracellular organelles and systemic acid-base homeostasis through H+ secretion in the renal collecting ducts. V-ATPase dysfunction is associated with hereditary distal renal tubular acidosis (dRTA). ATP6V1B1 encodes the B1 subunit of V-ATPase that is integral to ATP hydrolysis and subsequent H+ transport. Patients with pathogenic ATP6V1B1 mutations often exhibit an early onset of sensorineural hearing loss. However, the mechanisms underlying this association remain unclear. We employed morpholino oligonucleotide-mediated knockdown and CRISPR/Cas9 gene editing to generate Atp6v1ba-deficient (atp6v1ba-/-) zebrafish as an ortholog model for ATP6V1B1. The atp6v1ba-/- zebrafish exhibited systemic acidosis and significantly smaller otoliths compared to wild-type siblings. Moreover, deficiency in Atp6v1ba led to degeneration of inner ear hair cells, with ultrastructural changes indicative of autophagy. Our findings indicate a critical role of ATP6V1B1 in regulating lysosomal pH and autophagy in hair cells, and the results provide insights into the pathophysiology of sensorineural hearing loss in dRTA. Furthermore, this study demonstrates that the atp6v1ba-/- zebrafish model is a valuable tool for further investigation into disease mechanisms and potential therapies for acidosis-related hearing impairment.

Zebrafish as a Useful Model System for Human Liver Disease.

Liver diseases represent a significant global health challenge, thereby necessitating extensive research to understand their intricate complexities and to develop effective treatments. In this context, zebrafish (Danio rerio) have emerged as a valuable model organism for studying various aspects of liver disease. The zebrafish liver has striking similarities to the human liver in terms of structure, function, and regenerative capacity. Researchers have successfully induced liver damage in zebrafish using chemical toxins, genetic manipulation, and other methods, thereby allowing the study of disease mechanisms and the progression of liver disease. Zebrafish embryos or larvae, with their transparency and rapid development, provide a unique opportunity for high-throughput drug screening and the identification of potential therapeutics. This review highlights how research on zebrafish has provided valuable insights into the pathological mechanisms of human liver disease.

Involvement of clusterin expression in the refractory response of pancreatic cancer cells to a MEK inhibitor.

Constitutive activation of the mitogen-activated protein kinase (MAPK) signaling pathway is essential for tumorigenesis of pancreatic ductal adenocarcinoma (PDAC). To date, however, almost all clinical trials of inhibitor targeting this pathway have failed to improve the outcome of patients with PDAC. We found that implanted MIA Paca2, a human PDAC cell line sensitive to a MAPK inhibitor, PD0325901, became refractory within a week after treatment. By comparing the expression profiles of MIA Paca2 before and after acquisition of the refractoriness to PD0325901, we identified clusterin (CLU) as a candidate gene involved. CLU was shown to be induced immediately after treatment with PD0325901 or expressed primarily in more than half of PDAC cell lines, enhancing cell viability by escaping from apoptosis. A combination of PD0325901 and CLU downregulation was found to synergistically or additively reduce the proliferation of PDAC cells. In surgically resected PDAC tissues, overexpression of CLU in cancer cells was observed immunohistochemically in approximately half of the cases studied. Collectively, our findings highlight the mechanisms responsible for the rapid refractory response to MEK inhibitor in PDAC cells, suggesting a novel therapeutic strategy that could be applicable to patients with PDAC using inhibitor targeting the MAPK signaling pathway and CLU.

Enhanced phosphorylation of c-Jun by cisplatin treatment as a potential predictive biomarker for cisplatin response in combination with patient-derived tumor organoids.

Despite recent advances in sequencing technology and large-scale drug screenings employing hundreds of cell lines, the predictive accuracy of mutation-based biomarkers is still insufficient as a guide for cancer therapy. Therefore, novel types of diagnostic methods using alternative biomarkers would be highly desirable. We have hypothesized that sensitivity-specific changes in the phosphorylation of signaling molecules could be useful in this respect. Here, with the aim of developing a method for predicting the response of cancers to cisplatin using a combination of specific biomarker(s) and patient-derived tumor organoids (PDOs), we found that cisplatin-sensitive cell lines or PDOs showed enhanced phosphorylation of c-Jun (p-c-Jun) within 24 h after cisplatin treatment. We also compared the responses of 6 PDOs to cisplatin with the therapeutic effect of neoadjuvant chemotherapy (docetaxel/cisplatin/5-fluorouracil) in 6 matched patients. Mechanistically, the c-Jun induction was partly related to TNF signaling induced by cisplatin. Our data suggest that enhanced phosphorylation of c-Jun in response to cisplatin treatment could be a predictive biomarker for the efficacy of cisplatin in selected cancer patients.

Tyrosine pre-transfer RNA fragments are linked to p53-dependent neuronal cell death via PKM2.

Fragments of transfer RNA (tRNA), derived either from pre-tRNA or mature tRNA, have been discovered to play an essential role in the pathogenesis of various disorders such as neurodegenerative disease. CLP1 is an RNA kinase involved in tRNA biogenesis, and mutations in its encoding gene are responsible for pontocerebellar hypoplasia type-10. Mutation of the CLP1 gene results in the accumulation of tRNA fragments of several different kinds. These tRNA fragments are expected to be associated with the disease pathogenesis. However, it is still unclear which of the tRNA fragments arising from the CLP1 gene mutation has the greatest impact on the onset of neuronal disease. We found that 5' tRNA fragments derived from tyrosine pre-tRNA (5' Tyr-tRF) caused p53-dependent neuronal cell death predominantly more than other types of tRNA fragment. We also showed that 5' Tyr-tRF bound directly to pyruvate kinase M2 (PKM2). Injection of zebrafish embryos with PKM2 mRNA ameliorated the neuronal defects induced in zebrafish embryos by 5' Tyr-tRF. Our findings partially uncovered a mechanistic link between 5' Tyr-tRF and neuronal cell death that is regulated by PKM2.

AIF-regulated oxidative phosphorylation supports lung cancer development.

Cancer is a major and still increasing cause of death in humans. Most cancer cells have a fundamentally different metabolic profile from that of normal tissue. This shift away from mitochondrial ATP synthesis via oxidative phosphorylation towards a high rate of glycolysis, termed Warburg effect, has long been recognized as a paradigmatic hallmark of cancer, supporting the increased biosynthetic demands of tumor cells. Here we show that deletion of apoptosis-inducing factor (AIF) in a KrasG12D-driven mouse lung cancer model resulted in a marked survival advantage, with delayed tumor onset and decreased malignant progression. Mechanistically, Aif deletion leads to oxidative phosphorylation (OXPHOS) deficiency and a switch in cellular metabolism towards glycolysis in non-transformed pneumocytes and at early stages of tumor development. Paradoxically, although Aif-deficient cells exhibited a metabolic Warburg profile, this bioenergetic change resulted in a growth disadvantage of KrasG12D-driven as well as Kras wild-type lung cancer cells. Cell-autonomous re-expression of both wild-type and mutant AIF (displaying an intact mitochondrial, but abrogated apoptotic function) in Aif-knockout KrasG12D mice restored OXPHOS and reduced animal survival to the same level as AIF wild-type mice. In patients with non-small cell lung cancer, high AIF expression was associated with poor prognosis. These data show that AIF-regulated mitochondrial respiration and OXPHOS drive the progression of lung cancer.

Tricarboxylic acid cycle activity suppresses acetylation of mitochondrial proteins during early embryonic development in Caenorhabditis elegans.

The tricarboxylic acid (TCA) cycle (or citric acid cycle) is responsible for the complete oxidation of acetyl-CoA and formation of intermediates required for ATP production and other anabolic pathways, such as amino acid synthesis. Here, we uncovered an additional mechanism that may help explain the essential role of the TCA cycle in the early embryogenesis of Caenorhabditis elegans. We found that knockdown of citrate synthase (cts-1), the initial and rate-limiting enzyme of the TCA cycle, results in early embryonic arrest, but that this phenotype is not because of ATP and amino acid depletions. As a possible alternative mechanism explaining this developmental deficiency, we observed that cts-1 RNAi embryos had elevated levels of intracellular acetyl-CoA, the starting metabolite of the TCA cycle. Of note, we further discovered that these embryos exhibit hyperacetylation of mitochondrial proteins. We found that supplementation with acetylase-inhibiting polyamines, including spermidine and putrescine, counteracted the protein hyperacetylation and developmental arrest in the cts-1 RNAi embryos. Contrary to the hypothesis that spermidine acts as an acetyl sink for elevated acetyl-CoA, the levels of three forms of acetylspermidine, N1-acetylspermidine, N8-acetylspermidine, and N1,N8-diacetylspermidine, were not significantly increased in embryos treated with exogenous spermidine. Instead, we demonstrated that the mitochondrial deacetylase sirtuin 4 (encoded by the sir-2.2 gene) is required for spermidine's suppression of protein hyperacetylation and developmental arrest in the cts-1 RNAi embryos. Taken together, these results suggest the possibility that during early embryogenesis, acetyl-CoA consumption by the TCA cycle in C. elegans prevents protein hyperacetylation and thereby protects mitochondrial function.

The Tumor Suppressor Hace1 Is a Critical Regulator of TNFR1-Mediated Cell Fate.

The HECT domain E3 ligase HACE1 has been identified as a tumor suppressor in multiple cancers. Here, we report that HACE1 is a central gatekeeper of TNFR1-induced cell fate. Genetic inactivation of HACE1 inhibits TNF-stimulated NF-κB activation and TNFR1-NF-κB-dependent pathogen clearance in vivo. Moreover, TNF-induced apoptosis was impaired in hace1 mutant cells and knockout mice in vivo. Mechanistically, HACE1 is essential for the ubiquitylation of the adaptor protein TRAF2 and formation of the apoptotic caspase-8 effector complex. Intriguingly, loss of HACE1 does not impair TNFR1-mediated necroptotic cell fate via RIP1 and RIP3 kinases. Loss of HACE1 predisposes animals to colonic inflammation and carcinogenesis in vivo, which is markedly alleviated by genetic inactivation of RIP3 kinase and TNFR1. Thus, HACE1 controls TNF-elicited cell fate decisions and exerts tumor suppressor and anti-inflammatory activities via a TNFR1-RIP3 kinase-necroptosis pathway.

CLP1 links tRNA metabolism to progressive motor-neuron loss.

CLP1 was the first mammalian RNA kinase to be identified. However, determining its in vivo function has been elusive. Here we generated kinase-dead Clp1 (Clp1(K/K)) mice that show a progressive loss of spinal motor neurons associated with axonal degeneration in the peripheral nerves and denervation of neuromuscular junctions, resulting in impaired motor function, muscle weakness, paralysis and fatal respiratory failure. Transgenic rescue experiments show that CLP1 functions in motor neurons. Mechanistically, loss of CLP1 activity results in accumulation of a novel set of small RNA fragments, derived from aberrant processing of tyrosine pre-transfer RNA. These tRNA fragments sensitize cells to oxidative-stress-induced p53 (also known as TRP53) activation and p53-dependent cell death. Genetic inactivation of p53 rescues Clp1(K/K) mice from the motor neuron loss, muscle denervation and respiratory failure. Our experiments uncover a mechanistic link between tRNA processing, formation of a new RNA species and progressive loss of lower motor neurons regulated by p53.

SOCS, Inflammation, and Autoimmunity.

Cytokines play essential roles in innate and adaptive immunity. However, excess cytokines or dysregulation of cytokine signaling will cause a variety of diseases, including allergies, autoimmune diseases, inflammation, and cancer. Most cytokines utilize the so-called Janus kinase-signal transducers and activators of transcription pathway. This pathway is negatively regulated by various mechanisms including suppressors of cytokine signaling (SOCS) proteins. SOCS proteins bind to JAK or cytokine receptors, thereby suppressing further signaling events. Especially, suppressor of cytokine signaling-1 (SOCS1) and SOCS3 are strong inhibitors of JAKs, because these two contain kinase inhibitory region at the N-terminus. Studies using conditional knockout mice have shown that SOCS proteins are key physiological as well as pathological regulators of immune homeostasis. Recent studies have also demonstrated that SOCS1 and SOCS3 are important regulators of helper T cell differentiation and functions. This review focuses on the roles of SOCS1 and SOCS3 in T cell mediated inflammatory diseases.

RANKL/RANK-beyond bones.

Receptor-activator of NF-κB ligand (TNFSF11, also known as RANKL, OPGL, TRANCE, and ODF) and its tumor necrosis factor (TNF)-family receptor RANK are essential regulators of bone remodeling, lymph node formation, establishment of the thymic microenvironment, mammary gland development during pregnancy, and bone metastasis in cancer. We have recently also reported that the RANKL/RANK system controls the incidence and onset of sex hormone, progestin-driven breast cancer. RANKL and RANK are also expressed in the central nervous systems where they play an essential role in body temperature regulation. RANKL activates brain regions involved in thermoregulation and induces fever via the COX2-PGE(2)/EP3R pathway. Moreover, female mice with a RANK gene deleted in neurons and astrocytes exhibit increased basal body temperature, suggesting that the RANKL/RANK system also controls physiological thermoregulation in females under the control of sex hormones. This review will summarize the recently emerging role of the RANKL/RANK signaling axis in mammary gland development, cancer metastasis, hormone-derived breast cancer development, and thermal regulation. Furthermore, we will highlight the striking therapeutic potential of this pathway and provide a molecular rationale for consideration of targeting RANKL/RANK in diseases such as breast cancer.

Physiology and pathophysiology of the RANKL/RANK system.

The TNF family molecule RANKL and its receptor RANK are key regulators of bone remodeling, lymph node formation, and mammary gland development during pregnancy. RANKL and RANK are also expressed in the central nervous systems (CNS). However, the functional relevance of RANKL/RANK in the brain was entirely unknown. Recently, our group reported that the RANKL/RANK signaling pathway has an essential role in the central regulation of body temperature via the prostaglandin axis. This review discusses novel aspects of the RANKL/RANK system as key regulators of fever and female basal body temperature in the CNS.

Central control of fever and female body temperature by RANKL/RANK.

Receptor-activator of NF-kappaB ligand (TNFSF11, also known as RANKL, OPGL, TRANCE and ODF) and its tumour necrosis factor (TNF)-family receptor RANK are essential regulators of bone remodelling, lymph node organogenesis and formation of a lactating mammary gland. RANKL and RANK are also expressed in the central nervous system. However, the functional relevance of RANKL/RANK in the brain was entirely unknown. Here we report that RANKL and RANK have an essential role in the brain. In both mice and rats, central RANKL injections trigger severe fever. Using tissue-specific Nestin-Cre and GFAP-Cre rank(floxed) deleter mice, the function of RANK in the fever response was genetically mapped to astrocytes. Importantly, Nestin-Cre and GFAP-Cre rank(floxed) deleter mice are resistant to lipopolysaccharide-induced fever as well as fever in response to the key inflammatory cytokines IL-1beta and TNFalpha. Mechanistically, RANKL activates brain regions involved in thermoregulation and induces fever via the COX2-PGE(2)/EP3R pathway. Moreover, female Nestin-Cre and GFAP-Cre rank(floxed) mice exhibit increased basal body temperatures, suggesting that RANKL and RANK control thermoregulation during normal female physiology. We also show that two children with RANK mutations exhibit impaired fever during pneumonia. These data identify an entirely novel and unexpected function for the key osteoclast differentiation factors RANKL/RANK in female thermoregulation and the central fever response in inflammation.

Suppressor of cytokine signaling 1 protects mice against concanavalin A-induced hepatitis by inhibiting apoptosis.

UNLABELLED: Acute liver failure is associated with significant mortality. However, the underlying pathophysiological mechanism is not yet fully understood. Suppressor of cytokine signaling-1 (SOCS1), which is a negative-feedback molecule for cytokine signaling, has been shown to be rapidly induced during liver injury. Here, using liver-specific SOCS1-conditional-knockout mice, we demonstrated that SOCS1 deletion in hepatocytes enhanced concanavalin A (ConA)-induced hepatitis, which has been shown to be dependent on activated T and natural killer T (NKT) cells. Although serum cytokine level and NKT cell activation were similar in wild-type (WT) and SOCS1-deficient mice after ConA treatment, proapoptotic signals, including signal transducers and activators of transcription 1 (STAT1) and Jun-terminal kinase (JNK) activation, were enhanced in SOCS1-deficient livers compared with those in WT livers. SOCS1-deficient hepatocytes had higher expression of Fas antigen and were more sensitive to anti-Fas antibody-induced apoptosis than were WT hepatocytes. Furthermore, SOCS1-deficient hepatocytes were more sensitive to tumor necrosis factor (TNF)-alpha-induced JNK activation and apoptosis. These data indicate that SOCS1 is important to the prevention of hepatocyte apoptosis induced by Fas and TNF-alpha. In contrast, SOCS1 overexpression in the liver by adenoviral gene transfer prevented ConA-induced liver injury. CONCLUSION: These findings indicate that SOCS1 plays important negative roles in fulminant hepatitis and that forced expression of SOCS1 is therapeutic in preventing hepatitis.

IFNgamma-dependent, spontaneous development of colorectal carcinomas in SOCS1-deficient mice.

Approximately 20% of human cancers are estimated to develop from chronic inflammation. Recently, the NF-kappaB pathway was shown to play an essential role in promoting inflammation-associated cancer, but the role of the JAK/STAT pathway, another important signaling pathway of proinflammatory cytokines, remains to be investigated. Suppressor of cytokine signaling-1 (SOCS1) acts as an important physiological regulator of cytokine responses, and silencing of the SOCS1 gene by DNA methylation has been found in several human cancers. Here, we demonstrated that SOCS1-deficient mice (SOCS1-/- Tg mice), in which SOCS1 expression was restored in T and B cells on a SOCS1-/- background, spontaneously developed colorectal carcinomas carrying nuclear beta-catenin accumulation and p53 mutations at 6 months of age. However, interferon (IFN)gamma-/- SOCS1-/- mice and SOCS1-/- Tg mice treated with anti-IFNgamma antibody did not develop such tumors. STAT3 and NF-kappaB activation was evident in SOCS1-/- Tg mice, but these were not sufficient for tumor development because these are also activated in IFNgamma-/- SOCS1-/- mice. However, colons of SOCS1-/- Tg mice, but not IFNgamma-/- SOCS1-/- mice, showed hyperactivation of STAT1, which resulted in the induction of carcinogenesis-related enzymes, cyclooxygenase-2 and inducible nitric oxide synthase. These data strongly suggest that SOCS1 is a unique antioncogene which prevents chronic inflammation-mediated carcinogenesis by regulation of the IFNgamma/STAT1 pathways.

The role of suppressor of cytokine signaling 1 as a negative regulator for aberrant expansion of CD8alpha+ dendritic cell subset.

The suppressor of cytokine signaling (SOCS) 1 is a negative regulator in multiple cytokine-related aspects to maintain immunological homeostasis. Here, we studied a role of SOCS1 on dendritic cell (DC) maturation in the mice lacking either TCRalpha chain or CD28 in SOCS1-deficient background, and found that the SOCS1 could restore acute phase of inflammatory response in SOCS1-deficient mice. The CD11c+ CD8- DC population in freshly isolated splenic DCs from normal mice highly expressed SOCS1. However, in SOCS1-deficient environment, the proportion of CD8alpha+ DCs (CD8 DCs) noticeably increased without affecting the cell number of conventional and plasmacytoid DC populations. This population revealed the CD11cdull CD8alpha+ CD11b- CD45RA- B220- phenotype, which is a minor population in normal mice. Localization of the abnormal CD8 DCs in splenic microenvironments was mainly restricted to deep within red pulp. The CD8 DCs secrete a large amount of IFN-gamma, IL-12 and B lymphocyte stimulator/B cell activation factor of the tumor necrosis factor family in response to LPS and CpG stimulation. This is responsible for the development of DC-mediated systemic autoimmunity in the old age of SOCS1-deficient mice. Moreover, the CD8 DC subsets expressed more indoleamine 2,3-dioxygenase and IL-10, and hence inhibit the allogeneic proliferative T cell response and antigen-induced Th1 responses. Therefore, SOCS1 expression during DC maturation plays a role in surveillance in controlling the aberrant expansion of abnormal DC subset to maintain homeostasis of immune system.

Induction of hyper Th1 cell-type immune responses by dendritic cells lacking the suppressor of cytokine signaling-1 gene.

Suppressor of cytokine signaling (SOCS1/JAB) has been shown to play an important role in regulating dendritic cell (DC) function and suppressing inflammatory diseases and systemic autoimmunity. However, role of SOCS1 in DCs for the initiation of Th cell response has not been clarified. Here we demonstrate that SOCS1-deficient DCs induce stronger Th1-type responses both in vitro and in vivo. SOCS1-deficient DCs induced higher IFN-gamma production from naive T cells than wild-type (WT) DCs in vitro. Lymph node T cells also produced a higher amount of IFN-gamma when SOCS1-deficient bone marrow-derived DCs (BMDCs) were transferred in vivo. Moreover, SOCS1(-/-) BMDCs raised more effective anti-tumor immunity than WT BMDCs. Microarray analysis revealed that IFN-inducible genes were highly expressed in SOCS1-deficient DCs without IFN stimulation, suggesting hyper STAT1 activation in SOCS1(-/-) DCs. These phenotypes of SOCS1-deficient DCs were similar to those of CD8alpha(+) DCs, and in the WT spleen, SOCS1 is expressed at higher levels in the Th2-inducing CD4(+) DC subset, relative to the Th1-inducing CD8alpha(+) DC subset. We propose that reduction of the SOCS1 gene expression in DCs leads to CD8alpha(+) DC-like phenotype which promotes Th1-type hyperresponses.