NLRP3 inflammasome-mediated choroid plexus hypersecretion contributes to hydrocephalus after intraventricular hemorrhage via phosphorylated NKCC1 channels.

BACKGROUND: Hydrocephalus is a severe complication of intracerebral hemorrhage with ventricular extension (ICH-IVH) and causes cerebrospinal fluid (CSF) accumulation. The choroid plexus epithelium plays an important role in CSF secretion and constitutes the blood-CSF barrier within the brain-immune system interface. Although the NLRP3 inflammasome, as a key component of the innate immune system, promotes neuroinflammation, its role in the pathogenesis of hydrocephalus after hemorrhage has not been investigated. Therefore, this study aimed to investigate the potential mechanism of NLRP3 in hydrocephalus to discover a potential marker for targeted therapy. METHODS: A rat model of hydrocephalus after ICH-IVH was developed through autologous blood infusion in wild-type and Nlrp3-/- rats. By studying the features and processes of the model, we investigated the relationship between the NLRP3 inflammasome and CSF hypersecretion in the choroid plexus. RESULTS: The ICH-IVH model rats showed ventricular dilation accompanied by CSF hypersecretion for 3 days. Based on the choroid plexus RNA-seq and proteomics results, we found that an inflammatory response was activated. The NLRP3 inflammasome was investigated, and the expression levels of NLRP3 inflammasome components reached a peak at 3 days after ICH-IVH. Inhibition of NLRP3 by an MCC950 inflammasome inhibitor or Nlrp3 knockout decreased CSF secretion and ventricular dilation and attenuated neurological deficits after ICH-IVH. The mechanism underlying the neuroprotective effects of NLRP3 inhibition involved decreased phosphorylation of NKCC1, which is a major protein that regulates CSF secretion by altering Na+- and K+-coupled water transport, via MCC950 or Nlrp3 knockout. In combination with the in vitro experiments, this experiment confirmed the involvement of the NLRP3/p-NKCC1 pathway and Na+ and K+ flux. CONCLUSIONS: This study demonstrates that NKCC1 phosphorylation in the choroid plexus epithelium promotes NLRP3 inflammasome-mediated CSF hypersecretion and that NLRP3 plays an important role in the pathogenesis of hydrocephalus after hemorrhage. These findings provide a new therapeutic strategy for treating hydrocephalus.

Inhibiting Microglia-Derived NLRP3 Alleviates Subependymal Edema and Cognitive Dysfunction in Posthemorrhagic Hydrocephalus after Intracerebral Hemorrhage via AMPK/Beclin-1 Pathway.

For posthemorrhagic hydrocephalus (PHH) patients, whether occur subependymal edema indicates poor outcomes, partially manifested as cognitive impairment. In the brain, NLRP3 inflammasome mainly derived from microglia/macrophages is involved in proinflammatory and neurodeficits after hemorrhage, and autophagy is vital for neuronal homeostasis and functions. Accumulating evidence suggest that NLRP3 inflammasome and autophagy played an essential role after intracerebral hemorrhage (ICH). We aimed to dissect the mechanisms underlying subependymal edema formation and cognitive dysfunction. Here, based on the hydrocephalus secondary to ICH break into ventricular (ICH-IVH) in rats, this study investigated whether microglia/macrophage-derived NLRP3 induced subependymal edema formation and neuron apoptosis in subventricular zones (SVZ). In the acute phase of ICH-IVH, both the expression of NLRP3 inflammasome of microglia/macrophages and the autophagy of neurons were upregulated. The activated NLRP3 in microglia/macrophages promoted the release of IL-1beta to extracellular, which contributed to excessive autophagy, leading to neurons apoptosis both in vivo and in vitro through the AMPK/Beclin-1 pathway combined with transcriptomics. Administration of MCC950 (NLRP3 inflammasome specific inhibitor) after ICH-IVH significantly reduced edema formation and improved cognitive dysfunction. Thus, inhibiting NLRP3 activation in SVZ may be a promising therapeutic strategy for PHH patients that warrants further investigation.

Efficacy and safety of a nanoparticle therapeutic vaccine in patients with chronic hepatitis B: A randomized clinical trial.

BACKGROUND AND AIM: HBV DNA can be reduced using antiviral drugs in patients with chronic hepatitis B (CHB); however, the rate of HBeAg seroconversion remains low. A clinical trial was conducted to assess the efficacy and safety of a de novo designed liposome-based nanoparticle lipopeptide vaccine, εPA-44, for CHB. APPROACH AND RESULTS: A two-stage phase 2 trial, which included a 76-week, randomized, double-blind, placebo-controlled trial (stage 1) and a 68-week open-label extension (stage 2), was conducted in 15 centers across China (Clinicaltrials.gov No. NCT00869778). In stage 1, 360 human leukocyte antigen A2 (HLA-A2)-positive and HBeAg-positive patients were randomly and equally distributed to receive six subcutaneous injections of 600 µg or 900 µg εPA-44 or placebo at week 0, 4, 8, 12, 20, and 28. In stage 2, 183 patients received extended 900 µg εPA-44, and 26 patients were observed for relapse without further treatment. The primary endpoint was the percentage of patients with HBeAg seroconversion at week 76. At week 76, patients receiving 900 µg εPA-44 achieved significantly higher HBeAg seroconversion rate (38.8%) versus placebo (20.2%) (95% CI, 6.9-29.6%; p = 0.002). With a combined endpoint of HBeAg seroconversion, alanine aminotransferase normalization and HBV DNA < 2,000 IU/mL, both 900 µg (18.1%) and 600 µg (14.3%), resulted in significantly higher rate versus placebo (5.0%) (p = 0.002 and p = 0.02, respectively) at week 76. In stage 2, none (0 of 20) of 900 µg εPA-44-treated patients experienced serologic relapse. The safety profile of εPA-44 was comparable to that of placebo. CONCLUSIONS: Among HLA-A2-positive patients with progressive CHB, a finite duration of 900 µg εPA-44 monotherapy resulted in significantly higher HBeAg seroconversion rate than placebo and sustained off-treatment effect. A phase 3 trial is ongoing (ChiCTR2100043708).

Inhibition of plasma kallikrein mitigates experimental hypertension-enhanced cerebral hematoma expansion.

RATIONALE: Hematoma expansion (HE) aggravates brain injury after intracerebral hemorrhage (ICH) and hypertension is a key contributor to HE. Plasma kallikrein (PK) is involved in hemorrhagic transformation in ischemic stroke mice. This study was conducted to explore the role of PK in HE in hypertensive ICH. METHODS: Hypertension was achieved by continuous infusion of angiotensin II (Ang II) with an osmotic pump in C57BL/6 mice. ICH was achieved by stereotactic intrastriatal injection of blood. PK-specific antibody and platelet glycoprotein VI (GPVI) agonists were administered to intervene in hematoma expansion. The hematoma volume was indicated by the erythrocyte components hemoglobin and carbonic anhydrase-1 in the ipsilateral brain hemisphere. RESULTS: Ang II-induced hypertensive mice showed enhanced hematoma expansion and worsened neurologic deficits after ICH modeling. Moreover, intrastriatal injection of blood from Ang II-treated mice into normal mice increased the area of secondary hemorrhage more than blood from untreated mice. Mechanistically, elevated PK was found in Ang II-infused mice whereas, inhibition of PK and administration of the GPVI agonist convulxin decreased hematoma expansion and improved neurologic deficits after ICH. CONCLUSIONS: These findings suggest that PK inhibition and GPVI agonist treatment might serve as potential methods to intervene in HE after ICH.

MitoQ attenuates brain damage by polarizing microglia towards the M2 phenotype through inhibition of the NLRP3 inflammasome after ICH.

Microglial phenotype plays an important role in secondary injury after intracerebral haemorrhage (ICH), with M1 microglia promoting inflammatory injury and M2 microglia inhibiting neuroinflammation and promoting haematoma absorption. However, there is no effective intervention for regulating the phenotypic transformation of microglia after ICH. This study aimed to elucidate the protective effect of MitoQ, a selective mitochondrial ROS antioxidant, against microglial M1 state polarization and secondary brain injury. The in vivo data showed that MitoQ attenuated neurological deficits and decreased inflammation, oedema and haematoma volume after ICH. In addition, MitoQ decreased the expression of M1 markers and increased the expression of M2 markers both in vivo and in vitro after ICH. Mechanistically, MitoQ blocked overproduction of mitochondrial ROS and activation of the NLRP3 inflammasome in FeCl2-treated microglia. Moreover, NLRP3 siRNA shifted FeCl2-treated microglia from the M1 to the M2 cells, revealing that MitoQ-induce polarization states may be mediated by the mitochondrial ROS/NLRP-3 pathway. In summary, MitoQ alleviates secondary brain injury and accelerates haematoma resolution by shifting microglia towards the M2 phenotype after ICH.

Inhibition of Mitochondrial ROS by MitoQ Alleviates White Matter Injury and Improves Outcomes after Intracerebral Haemorrhage in Mice.

White matter injury (WMI) is an important cause of high disability after intracerebral haemorrhage (ICH). It is widely accepted that reactive oxygen species (ROS) contributes to WMI, but there is still no evidence-based treatment. Here, mitoquinone (MitoQ), a newly developed selective mitochondrial ROS scavenger, was used to test its neuroprotective potential. The data showed that MitoQ attenuated motor function deficits and motor-evoked potential (MEP) latency prolongation. Further research found that MitoQ blunted the loss of oligodendrocytes and oligodendrocyte precursor cells, therefore reduced demyelination and axon swelling after ICH. In the in vitro experiments, MitoQ, but not the nonselective antioxidant, almost completely attenuated the iron-induced membrane potential decrease and cell death. Mechanistically, MitoQ blocked the ATP deletion and mitochondrial ROS overproduction. The present study demonstrates that the selective mitochondrial ROS scavenger MitoQ may improve the efficacy of antioxidant treatment of ICH by white matter injury alleviation.

Nicotinamide riboside rescues angiotensin II-induced cerebral small vessel disease in mice.

AIMS: Hypertension is a leading cause of cerebral small vessel disease (CSVD). Currently, treatments for CSVD are limited. Nicotinamide riboside (NR) can protect against vascular injury and cognitive impairment in neurodegenerative diseases. In this study, the protective effects of NR against angiotensin - (Ang -)-induced CSVD were evaluated. METHODS: To explore the effects of NR in CSVD, C57BL/6 mice were infused with Ang -, and NR was added to the food of the mice for 28 days. Then, short-term memory, blood-brain barrier (BBB) integrity, and endothelial function were detected. Arteriole injury and glial activation were also evaluated. RESULTS: Our data showed that mice infused with Ang - exhibited decreased short-term memory function and BBB leakage due to decreased claudin-5 expression and increased caveolae-mediated endocytosis after 28 days. Furthermore, Ang - decreased the expression of α-smooth muscle actin (α-SMA) and increased the expression of proliferating cell nuclear antigen (PCNA) in arterioles and decreased the expression of neurofilament 200 (NF200) and myelin basic protein (MBP) in the white matter. These CSVD-related damages induced by Ang - were inhibited by NR administration. Moreover, NR administration significantly reduced glial activation around the vessels. CONCLUSION: Our results indicated that NR administration alleviated Ang --induced CSVD by protecting BBB integrity, vascular remodeling, neuroinflammation, and white matter injury (WMI)-associated cognitive impairment.

Lithium treatment mitigates white matter injury after intracerebral hemorrhage through brain-derived neurotrophic factor signaling in mice.

Intracerebral hemorrhage (ICH), a subtype of stroke with high morbidity and mortality, occurs mainly in the basal ganglia and causes white matter injury (WMI), resulting in severe motor dysfunction and poor prognosis in patients. The preservation of the white matter around the hematoma is crucial for motor function recovery, but there is currently no effective treatment for WMI following ICH. Lithium has been widely used for the treatment of bipolar disorder for decades. Although the protective effects of lithium on neurodegenerative diseases and cerebral trauma have been studied in recent years, whether it can be used to alleviate WMI after ICH remains to be researched. The results of this study revealed that ICH caused significant functional and pathological abnormalities in mice. After LiCl was administered to mice with ICH, behavioural performance and electrophysiological functions were improved and ICH-induced white matter pathological injury, including myelin sheath and axonal degeneration, was ameliorated. Furthermore, LiCl treatment decreased the death of mature oligodendrocytes (OLGs) in ICH mice, which may have been attributed to the enhanced expression of brain-derived neurotrophic factor (BDNF) regulated by the LiCl-induced inhibition of glycogen synthase kinase-3ß (GSK-3ß). The decreased death of OLGs was closely associated with decreased destruction of the myelin sheath and alleviated degradation of the axons. In summary, this study suggests that the protective effect of lithium on WMI after ICH might be related to an increased level of BDNF and that LiCl treatment may be a potential therapeutic method to palliate WMI after ICH.

HBx Protein Contributes to Liver Carcinogenesis by H3K4me3 Modification Through Stabilizing WD Repeat Domain 5 Protein.

BACKGROUND AND AIMS: Cancer is typically considered as a genetic and epigenetic disease. Although numerous studies have indicated that an aberrant structure, function, or expression level of epigenetic enzymes contribute to many tumor types, precisely how the epigenetic mechanisms are involved in the hepatitis B virus (HBV)-induced hepatocellular carcinoma (HCC) remains unknown. APPROACH AND RESULTS: In this study, we found that the WD repeat domain 5 protein (WDR5)-a core subunit of histone H3 lysine 4 methyltransferase complexes, which catalyze the generation of histone H3 lysine 4 trimethylation (H3K4me3) modification-is highly expressed in HBV-related HCC and promotes HCC development. WDR5 plays a critical role in HBV-driven cell proliferation and tumor growth in mice, and the WDR5-0103 small-molecule inhibitor of WDR5 activity compromises HBV- and hepatitis B x protein (HBx)-driven tumor proliferation. The aberrantly high WDR5 protein level was found to involve HBx through its stabilization of the WDR5 protein by inhibiting the interaction between the damage-specific DNA-binding protein 1/cullin-4 and WDR5, causing decreased ubiquitination of the WDR5 protein. HBx was found to colocalize with WDR5 on chromatin genome wide and promotes genome-wide H3K4me3 modification by means of WDR5. Furthermore, the recruitment of HBx to promoters of target genes relied on its interaction with WDR5 through its α-helix domain. WDR5 was also found to promote HBV transcription through H3K4 modification of covalently closed circular DNA minichromosome, and WDR5-0103 was able to inhibit HBV transcription. Finally, the in vitro and in vivo data further proved that HBx exerted its tumor-promoting function in a WDR5-dependent manner. CONCLUSIONS: Our data reveals that WDR5 is a key epigenetic determinant of HBV-induced tumorigenesis and that the HBx-WDR5-H3K4me3 axis may be a potential therapeutic target in HBV-induced liver pathogenesis.

Quantitative Iron Neuroimaging Can Be Used to Assess the Effects of Minocycline in an Intracerebral Hemorrhage Minipig Model.

Iron-mediated toxicity is a key factor causing brain injury after intracerebral hemorrhage (ICH). This study was performed to investigate the noninvasive neuroimaging method for quantifying brain iron content using a minipig ICH model and assess the effects of minocycline treatment on ICH-induced iron overload and brain injury. The minipig ICH model was established by injecting 2 ml of autologous blood into the right basal ganglia, which were then subjected to the treatments of minocycline and vehicle. Furthermore, the quantitative susceptibility mapping (QSM) was used to quantify iron content, and diffusion tensor imaging (DTI) was performed to evaluate white matter tract. Additionally, we also performed immunohistochemistry, Western blot, iron assay, Perl's staining, brain water content, and neurological score to evaluate the iron overload and brain injury. Interestingly, we found that the ICH-induced iron overload could be accurately quantified by the QSM. Moreover, the minocycline was quite beneficial for protecting brain injury by reducing the lesion volume and brain edema, preventing brain iron accumulation, downsizing ventricle enlargement, and alleviating white matter injury and neurological deficits. In summary, we suggest that the QSM be an accurate and noninvasive method for quantifying brain iron level, and the minocycline may be a promising therapeutic agent for patients with ICH.

Modified behavioural tests to detect white matter injury- induced motor deficits after intracerebral haemorrhage in mice.

Motor function deficit induced by white matter injury (WMI) is one of the most severe complications of intracerebral haemorrhage (ICH). The degree of WMI is closely related to the prognosis of patients after ICH. However, the current behavioural assessment of motor function used in the ICH mouse model is mainly based on that for ischaemic stroke and lacks the behavioural methods that accurately respond to WMI. Here, a series of easy-to-implement behavioural tests were performed to detect motor deficits in mice after ICH. The results showed that the grip strength test and the modified pole test not only can better distinguish the degree of motor dysfunction between different volumes of blood ICH models than the Basso Mouse Scale and the beam walking test but can also accurately reflect the severity of WMI characterized by demyelination, axonal swelling and the latency of motor-evoked potential delay induced by ICH. In addition, after ICH, the results of grip tests and modified pole tests, rather than the Basso Mouse Scale and the beam walking test, were worse than those observed after intraventricular haemorrhage (IVH), which was used as a model of brain haemorrhage in non-white matter areas. These results indicate that the grip strength test and the modified pole test have advantages in detecting the degree of motor deficit induced by white matter injury after ICH in mice.

TRPA1 Activation-Induced Myelin Degradation Plays a Key Role in Motor Dysfunction After Intracerebral Hemorrhage.

Intracerebral hemorrhage (ICH) is a devastating disease that is characterized by high morbidity and high mortality. ICH has an annual incidence of 10-30/100,000 people and accounts for approximately 10%-30% of all types of stroke. ICH mostly occurs at the basal ganglia, which is rich in nerve fibers; thus, hemiplegia is quite common in ICH patients with partial sensory disturbance and ectopic blindness. In the clinic, those symptoms are considered to originate from the white matter injury in the area, but the exact mechanisms are unknown, and currently, no effective drug treatments are available to improve the prognosis. Clarifying the mechanisms will contribute to the development of new treatment methods for patients. The transient receptor potential ankyrin 1 (TRPA1) channel is a non-selective cation channel that plays a role in inflammatory pain sensation and nociception and may be a potential regulator in emotion, cognition and social behavior. Here, we report that TRPA1 is involved in myelin damage and oxidative stress injury in a mouse ICH model. Intervention with the TRPA1 channel may be a new method to improve the motor function of patients in the early stage of ICH.

G protein-coupled estrogen receptor 1 negatively regulates the proliferation of mouse-derived neural stem/progenitor cells via extracellular signal-regulated kinase pathway.

G protein-coupled estrogen receptor 1 (GPER1, also known as GPR30) has been reported to play a wide range of function in the central nervous system (CNS). However, whether GPER1 is expressed by neural stem/progenitor cells (NSPCs) and its role has not been established. Here, we found the expression of GPER1 in mouse-derived NSPCs via western blot and immunofluorescent staining. Moreover, we revealed that specific activation of GPER1 by the agonist G1 decreased the proliferation of NSPCs in a dose-dependent manner. The neurosphere formation assay and Ki67 staining further demonstrated that activation of GPER1 inhibited the proliferation of NSPCs. Additionally, the inhibitory effect of G1 on the proliferation of NSPCs could be blocked by the specific GPER1 antagonist G15. Intriguingly, ERK pathway was involved in the negative effect of GPER1 on the proliferation of NSPCs, because the phosphorylation level of ERK in NSPCs was remarkably decreased during G1 treatment. However, the antagonist G15 reversed the down-regulated level of p-ERK. Knock-down GPER1 also reversed the inhibitory effect of G1 on NSPCs proliferation. Together, our results provide the first evidence that GPER1 is expressed by NSPCs and its activation negatively modulates the proliferation of NSPCs, highlighting the importance of GPER1 in regulating NSPC behaviors.

MicroRNA-146a promotes IgE class switch in B cells via upregulating 14-3-3σ expression.

B cells play a critical role in immune responses both in physiological and pathological conditions, and microRNAs have been shown to play important roles in regulating B cell proliferation and function. MiR-146a has been shown to modulate T cell immunity, but its function in regulating B cell response remains partially understood. Our previous studies indicated that germinal center (GC) B cells are significantly expanded in miR-146a-overexpressing (TG) mice. In this study, we further characterized the roles of miR-146a in regulating humoral immune responses to specific antigens. We found that the production of IgE antibody were significantly elevated in TG mice, while the antibody affinity maturation of IgM and IgG were similar between TG mice and the normal controls. We further found higher IgE antibody levels in TG B cell culture supernatant than that in normal controls. A global protein expression comparison of B cells from TG mice and the normal controls through TMT proteomic assay showed that 14-3-3σ, a key factor of immunoglobulin class switch DNA recombination (CSR) in B cells, was highly up-regulated in B cells with overexpression of miR-146a, while Smad4, the target of miR-146a, was decreased. Using an asthma model induced by OVA immunization, we further confirmed the increased level of OVA specific IgE antibodies in TG mice. These results demonstrate that miR-146a enhances class switch and secretion of IgE in B cells by upregulating 14-3-3σ expression, and suggest that miR-146a may be a potential target for asthma therapy.

Rab40b upregulation correlates with the prognosis of gastric cancer by promoting migration, invasion, and metastasis.

Gastric cancer (GC) is the fourth most common cancer worldwide and is associated with a low 5-year survival rate of <24 % due to the tendency of early invasion and metastasis. Rab GTPases, which are master regulators of intracellular trafficking, have been shown to a play new role in the control of multiple tumor-related processes, including cell migration, invasion, proliferation, communication, and drug resistance. Here, we analyzed the mRNA expression levels of 63 Rab GTPases in samples from GC patients. Our data demonstrated that the expression level of Rab40b was significantly correlated with GC invasion classification (P < 0.01), lymph node metastasis (P < 0.01), and pathological stage (P < 0.01). High Rab40b mRNA expression was also correlated with shorter overall survival in patients with GC (P < 0.05). Moreover, knockdown of Rab40b protein reduced the migration and invasion of GC cells, while overexpression of Rab40b significantly promoted GC cell metastasis in nude mice. Our results also showed that Rab40b is a target gene of miR-204 and further demonstrated that Rab40b is negatively correlated with miR-204 in GC tissues. These findings indicate that Rab40b might be a novel prognostic marker and a candidate biological therapeutic target for GC.

Preparation of polypeptides comprising multiple TAA peptides.

Polypeptides consisting of multiple tumor-associated antigen epitopes (multiepitope peptides) are commonly used as therapeutic peptide cancer vaccines in experimental studies and clinical trials. These methods include polypeptides composed of multiple major histocompatibility complex (MHC) class I-restricted cytotoxic T cell (CTL) epitopes and those containing multiple CTL epitopes and one T helper (Th) epitope. This chapter describes a complete set of methods for preparing multiepitope peptides and branched multiple antigen peptides (MAPs), including sequence design, peptide synthesis, purification, preservation, and the preparation of polypeptide solutions.

Hepatitis B virus induces IL-23 production in antigen presenting cells and causes liver damage via the IL-23/IL-17 axis.

IL-23 regulates myriad processes in the innate and adaptive immune systems, and is a critical mediator of the proinflammatory effects exerted by Th17 cells in many diseases. In this study, we investigated whether and how hepatitis B virus (HBV) causes liver damage directly through the IL-23 signaling pathway. In biopsied liver tissues from HBV-infected patients, expression of both IL-23 and IL-23R was remarkably elevated. In vivo observations also indicated that the main sources of IL-23 were myeloid dendritic cells (mDCs) and macrophages. Analysis of in vitro differentiated immature DCs and macrophages isolated from healthy donors revealed that the HBV surface antigen (HBsAg) efficiently induces IL-23 secretion in a mannose receptor (MR)-dependent manner. Culture with an endosomal acidification inhibitor and the dynamin inhibitor showed that, upon binding to the MR, the HBsAg is taken up by mDCs and macrophages through an endocytosis mechanism. In contrast, although the HBV core antigen (HBcAg) can also stimulate IL-23 secretion from mDCs, the process was MR- and endocytosis-independent. In addition, IL-23 was shown to be indispensible for HBsAg-stimulated differentiation of naïve CD4(+) T cells into Th17 cells, which were determined to be the primary source of IL-17 in HBV-infected livers. The cognate receptor, IL-17R, was found to exist on the hepatic stellate cells and mDCs, both of which might represent the potential target cells of IL-17 in hepatitis B disease. These data provide novel insights into a yet unrecognized mechanism of HBV-induced hepatitis, by which increases in IL-23 expression, through an MR/endocytosis-dependent or -independent manner, produce liver damage through the IL-23/IL-17 axis.

Cross-immunizing potential of tumor MAGE-A epitopes recognized by HLA-A*02:01-restricted cytotoxic T lymphocytes.

Almost all melanoma cells express at least one member of the MAGE-A antigen family, making the cytotoxic T cells (CTLs) epitopes with cross-immunizing potential in this family attractive candidates for the broad spectrum of anti-melanoma immunotherapy. In this study, four highly homologous peptides (P264: FLWGPRALA, P264I9: FLWGPRALI, P264V9: FLWGPRALV, and P264H8: FLWGPRAHA) from the MAGE-A antigens were selected by homologous alignment. All four peptides showed high binding affinity and stability to HLA-A*02:01 molecules, and could prime CTL immune responses in human PBMCs and in HLA-A*02:01/K(b) transgenic mice. CTLs elicited by the four epitope peptides could cross-lyse tumor cells expressing the mutual target antigens, except MAGE-A11 which was not tested. However, CTLs induced by P264V9 and P264I9 showed the strongest target cell lysis capabilities, suggesting both peptides may represent the common CTL epitopes shared by the eight MAGE-A antigens, which could induce more potent and broad-spectrum antitumor responses in immunotherapy.

Identification of interacting proteins of retinoid-related orphan nuclear receptor gamma in HepG2 cells.

The retinoid-related orphan nuclear receptor gamma (ROR γ) plays critical roles in regulation of development, immunity and metabolism. As transcription factor usually forms a protein complex to function, thus capturing and dissecting of the ROR γ protein complex will be helpful for exploring the mechanisms underlying those functions. After construction of the recombinant tandem affinity purification (TAP) plasmid, pMSCVpuro ROR γ-CTAP(SG), the nuclear localization of ROR γ-CTAP(SG) fusion protein was verified. Following isolation of ROR γ protein complex by TAP strategy, seven candidate interacting proteins were identified. Finally, the heat shock protein 90 (HSP90) and receptor-interacting protein 140 (RIP140) were confirmed to interplay with ROR γ by co-immunoprecipitation. Interference of HSP90 or/and RIP140 genes resulted in dramatically decreased expression of CYP2C8 gene, the ROR γ target gene. Data from this study demonstrate that HSP90 and RIP140 proteins interact with ROR γ protein in a complex format and function as co-activators in the ROR γ-mediated regulatory processes of HepG2 cells.

A novel splice variant of folate receptor 4 predominantly expressed in regulatory T cells.

BACKGROUND: Regulatory T cells (Tregs) are required for proper maintenance of immunological self-tolerance and immune homeostasis. Folate receptor 4 (FR4) is expressed at high levels in transforming growth factor-beta (TGF-ß)-induced Tregs and natural Tregs. Moreover, antibody-mediated targeting of FR4 is sufficient to mediate Treg depletion. RESULTS: In this study, we describe a novel FR4 transcript variant, FR4D3, in which exon 3 is deleted. The mRNA of FR4D3 encodes a FR4 variant truncated by 189 bp. FR4D3 was found to be predominantly expressed in CD4(+)CD25(+) Treg cells. Overexpression of FR4D3 in CD4(+)CD25(+) Treg cells in vitro stimulated proliferation, which may modulate the ability of these cells to bind and incorporate folic acid. CONCLUSIONS: Our results suggested that high levels of FR4D3 may be critical to support the substantial proliferative capacity of Treg cells.