Peripheral apolipoprotein E proteins and their binding to LRP1 antagonize Alzheimer's disease pathogenesis in the brain during peripheral chronic inflammation.

C-reactive protein (CRP) impacts apolipoprotein E4 (ApoE4) allele to increase Alzheimer's disease (AD) risk. However, it is unclear how the ApoE protein and its binding to LRP1 are involved. We found that ApoE2 carriers had the highest but ApoE4 carriers had the lowest concentrations of blood ApoE in both humans and mice; blood ApoE concentration was negatively associated with AD risk. Elevation of peripheral monomeric CRP (mCRP) reduced the expression of ApoE in ApoE2 mice, while it decreased ApoE-LRP1 binding in the brains of ApoE4 mice that was characterized by Proximity Ligation Assay. Both serum ApoE and brain ApoE-LRP1 binding were positively associated with the expression of pericytes that disappeared after mCRP treatment, and negatively associated with brain tauopathy and neuroinflammation in the presence of mCRP. In ApoE-/- mice, mCRP reduced the brain expression levels of synaptophysin and PSD95 and the positive relationship between ApoE-LRP1 binding and synaptophysin or PSD95 expression disappeared. Our study suggests that blood ApoE protects against AD pathogenesis by binding to LRP1 during peripheral chronic inflammation.

Monomeric C-reactive protein induces the cellular pathology of Alzheimer's disease.

Introduction: Human study shows that elevated C-reactive protein (CRP) in blood impacts apolipoprotein E (APOE) ε4, but not APOE ε3 or APOE ε2, genotype to increase the risk of Alzheimer's disease (AD). However, whether CRP is directly involved in cellular AD pathogenesis and in which type of neuronal cells of APOE ε4 carriers are unknown. Methods: We aimed to use different primary neuronal cells and investigate if CRP induces cellular AD pathology depending on APOE genotypes. Here the different primary neuronal cells from the different APOE genotype knock-in mice cortex were isolated and used. Results: Monomeric CRP (mCRP) increased amyloid beta production and, in parallel, induced tau phosphorylation in addition to their related proteins in the primary neurons in a pattern of APOE ε4 > APOE ε3 > APOE ε2 in a dose- and time-dependent manner. Consistently, mCRP induced the staining of other neurodegenerative biomarkers, including Fluoro-Jade B stain (FjB), TUNEL and Cleaved Caspase-3, in primary neurons in a similar pattern of APOE ε4 > APOE ε3 > APOE ε2. In contrast, pentameric CRP (pCRP) had a tendency to induce cellular AD pathology but did not reach statistical significance. On the other hand, it is intriguing that regardless of APOE genotype, mCRP did not influence the expressions of Iba-1 and CD68 in primary microglia or the expression of glial fibrillary acidic protein in primary astrocytes, and additionally mCRP did not affect the secretions of interleukin (IL)-1α, IL-1ß, and tumor necrosis factor α from these cells. Discussion: This is the first report to demonstrate that mCRP directly induces cellular AD pathogenesis in neurons in an APOE genotype-dependent pattern, suggesting that mCRP plays a role as a mediator involved in the APOE ε4-related pathway for AD during chronic inflammation. Highlights: Pentameric C-reactive protein (pCRP) can be dissociated irreversibly to form free subunits or monomeric CRP (mCRP) during and after the acute phase.mCRP increased amyloid beta production in the primary neurons in a pattern of apolipoprotein E (APOE) ε4 > APOE ε3 > APOE ε2 in a dose-dependent manner.mCRP induced the expression of phosphorylated tau in the primary neurons in a pattern of APOE ε4 > APOE ε3 > APOE ε2 in a dose- and time-dependent manner.mCRP plays an important mediator role in the APOE ε4-related pathway of Alzheimer's disease risk.

Monomeric C-reactive protein via endothelial CD31 for neurovascular inflammation in an ApoE genotype-dependent pattern: A risk factor for Alzheimer's disease?

In chronic peripheral inflammation, endothelia in brain capillary beds could play a role for the apolipoprotein E4 (ApoE4)-mediated risk for Alzheimer's disease (AD) risk. Using human brain tissues, here we demonstrate that the interactions of endothelial CD31 with monomeric C-reactive protein (mCRP) versus ApoE were linked with shortened neurovasculature for AD pathology and cognition. Using ApoE knock-in mice, we discovered that intraperitoneal injection of mCRP, via binding to CD31 on endothelial surface and increased CD31 phosphorylation (pCD31), leading to cerebrovascular damage and the extravasation of T lymphocytes into the ApoE4 brain. While mCRP was bound to endothelial CD31 in a dose- and time-dependent manner, knockdown of CD31 significantly decreased mCRP binding and altered the expressions of vascular-inflammatory factors including vWF, NF-κB and p-eNOS. RNAseq revealed endothelial pathways related to oxidative phosphorylation and AD pathogenesis were enhanced, but endothelial pathways involving in epigenetics and vasculogenesis were inhibited in ApoE4. This is the first report providing some evidence on the ApoE4-mCRP-CD31 pathway for the cross talk between peripheral inflammation and cerebrovasculature leading to AD risk.

Oral Amylin Treatment Reduces the Pathological Cascade of Alzheimer's Disease in a Mouse Model.

Intraperitoneal injection of amylin or its analog reduces Alzheimer's disease (AD) pathology in the brains. However, self-injecting amylin analogs is difficult for patients due to cognitive deficits. This work aims to study the effects of amylin on the brain could be achieved by oral delivery as some study reported that amylin receptor may be present in the gastrointestinal tract. A 6-week course of oral amylin treatment reduced components of AD pathology, including the levels of amyloid-ß, phosphorylated tau, and ionized calcium binding adaptor molecule 1. The treatment reduced active forms of cyclin-dependent kinase 5. Oral amylin treatment led to improvements in social deficit in AD mouse. Using immunofluorescence, we observed the amylin receptor complexed with the calcitonin receptor and receptor activity-modifying proteins in the enteric neurons. The study suggests the potential of the oral delivery of amylin analogs for the treatment of AD and other neurodegenerative diseases through enteric neurons.

Characterization of the effects of calcitonin gene-related peptide receptor antagonist for Alzheimer's disease.

Calcitonin gene-related peptide (cGRP) receptor antagonists effectively treat migraine through reducing neuroinflammation, vasoconstriction and possibly neruogenesis. Since neuroinflammation is also involved in the pathogenesis of Alzheimer's diseases (AD), we hypothesized and tested if a cGRP receptor antagonist, BIBN 4096 BS (BIBN), has effects on AD pathology. Using an AD mouse model, 5XFAD, with different ages, here we report that the BIBN treatment significantly increased the brain expression of PSD95, a postsynaptic protein, in both young and old AD mice. In parallel, BIBN improved learning and memory in the behavior test in the young, but not old, AD mice. The BIBN treatment reduced α-synuclein aggregation in both young and old AD mice. BIBN significantly decreased neuroinflammatory markers of ionized calcium binding adapter molecules-1 (Iba-1) and the p38 MAPK and NFκB signaling pathways in young, but not old, AD mice. The treatment also reduced the accumulation of amyloid-ß (Aß), and decreased tau phosphorylation through the pathway of CDK5/p25 in young mice only. Our study provides the evidence and suggests that the cGRP antagonists might be a therapeutic target to attenuate the pathological cascade and delay cognitive decline of AD in humans.

What we know and what we need to know about adenovirus 36-induced obesity.

BACKGROUND: Many internal and external factors are related to obesity. Pathogens that can induce obesity are the most interesting external factors. While the relationship between pathogenic human intestinal microbiota and obesity has been extensively studied, viruses have received relatively little attention. Among the human obesity-related viruses, adenovirus 36 (Ad36) is most commonly associated with obesity. METHODS: A literature search was conducted using the articles in the PubMed database published from April 1982 to April 2019. The following main keywords were used: ('adenovirus 36') and ('obesity') and ('cellular mechanism' or 'genetic factor' or 'immune response' or 'inflammation'). RESULTS: In this review, we have discussed the known facts and what requires to be understood regarding Ad36-induced obesity. In particular, we have summarized the cellular mechanism of Ad36-induced obesity, as well as the genetic and immunological factors affected by Ad36 infection. Ad36 infection increases adipogenesis in animals and humans. Ad36-induced inflammation contributes to angiogenesis in adipose tissues, thereby maintaining proper glycemic control and metabolic robustness. The E4orf1 protein derived from Ad36 is responsible for increasing glucose uptake due to the translocation of GLUT4 via the Ras-PI3K pathway, which is involved in 'distal' insulin signaling. CONCLUSIONS: We expect that this review will assist in guiding future investigations regarding Ad36-induced obesity. (1) Identification of the direct and indirect factors affecting Ad36-induced obesity and understanding their mechanism of action and (2) utilization of the Ad36-induced improvement in glycemic control for clinical applications, with efforts toward developing E4orf1-based drugs.

Effects of Amylin Against Amyloid-ß-Induced Tauopathy and Synapse Loss in Primary Neurons.

Recent studies demonstrate that peripheral amylin treatment reduces pathology in mouse models of Alzheimer's disease (AD). However, soluble and aggregated amylin are distinct species; while amylin is a physiological neuropeptide, amylin aggregation is a pathological factor for diabetes. We thus hypothesized that because of their similarity in secondary structures, amylin antagonizes amyloid-ß peptide (Aß)-induced AD pathology in neurons with a dose-dependent pattern. To test the hypothesis, we conducted both in vitro and in vivo experiments with different doses of amylin and with its analog, pramlintide. Here we report that a high concentration of either Aß or amylin alone induced tau phosphorylation (pTau) in primary neurons. Interestingly, with a low concentration, amylin had direct effects to reverse the Aß-induced pTau, as well as damaged neuronal synapses and neurite disorganization. However, when the concentration was high (10.24 µM), amylin lost the effects against the Aß-induced cellular AD pathology and, together with Aß, worsened tauopathy in neurons. In the 5XFAD AD mouse model, daily peripheral amylin treatment with a low dose (200 µg/kg) more effectively reduced amyloid burden, and increased synapse, but with a high dose (800 µg/kg), it more effectively reduced tauopathy. Correspondingly, amylin treatment improved learning and memory in these mice. It demonstrates that amylin has a dose-dependent U-shape effect against AD pathogenesis. Within a physiological range, amylin is a neuroprotective hormone against AD in neurons; but when both Aß and amylin concentrations are elevated, imbalance of Aß and amylin may contribute to brain AD pathogenesis.

Long-term survival outcome with tyrosine kinase inhibitors and surgical intervention in patients with metastatic or recurrent gastrointestinal stromal tumors: A 14-year, single-center experience.

The long-term effects of tyrosine kinase inhibitors (TKIs), including imatinib, and surgical intervention on advanced gastrointestinal stromal tumor (GIST) were evaluated. All 379 patients had metastatic or recurrent GIST and started 400 mg/d imatinib at the Asan Medical Center in periods 1 and 2 [2001-2007 (33.2%) and 2008-2014 (66.8%), respectively]. Men constituted 60.4%; median patient age and tumor size at the initiation of imatinib were 58.6 (14.6-85.5) years and 51 (0-324) mm, respectively, without differences between periods except for older age and less preimatinib surgery in period 2. Response and disease control rates with imatinib in measurable GIST were 63.1% and 94.3%, respectively, without differences between periods. More patients in period 2 underwent surgical resection for TKI-responsive diseases within the first 2 years (24.9%, P = 0.006). With a median follow-up of 6.1 years (2.5-16.0) in survivors, median progression-free survival (PFS) was 5.4 years [95% confidence interval (CI), 4.0-6.9]. Subsequent sunitinib (P = 0.066) and regorafenib (P = 0.003) were more commonly administered in period 2. Median overall survival (OS) was 8.8 years (95% CI, 7.8-9.7). PFS with imatinib (P = 0.002) and OS (P = 0.019) were significantly longer in period 2. Young age, smaller tumor size at the initiation of imatinib, KIT exon 11 mutation, surgical intervention, and period 2 were favorable factors for PFS and OS. Patients with advanced GIST showed better prognosis with the optimal use of imatinib, along with active surgical intervention and more common use of subsequent TKIs in period 2.

Nitazoxanide is active against Mycobacterium leprae.

Nitazoxanide (NTZ) is an anti-parasitic drug that also has activity against bacteria, including Mycobacterium tuberculosis. Our data using both radiorespirometry and live-dead staining in vitro demonstrate that NTZ similarly has bactericidal against M. leprae. Further, gavage of M. leprae-infected mice with NTZ at 25mg/kg provided anti-mycobacterial activity equivalent to rifampicin (RIF) at 10 mg/kg. This suggests that NTZ could be considered for leprosy treatment.

Amylin receptor ligands reduce the pathological cascade of Alzheimer's disease.

Amylin is an important gut-brain axis hormone. Since amylin and amyloid-ß peptide (Aß) share similar ß sheet secondary structure despite not having the same primary sequences, we hypothesized that the accumulation of Aß in the brains of subjects with Alzheimer's disease (AD) might compete with amylin for binding to the amylin receptor (AmR). If true, adding exogenous amylin type peptides would compete with Aß and reduce the AD pathological cascade, improving cognition. Here we report that a 10-week course of peripheral treatment with human amylin significantly reduced multiple different markers associated with AD pathology, including reducing levels of phospho-tau, insoluble tau, two inflammatory markers (Iba1 and CD68), as well as cerebral Aß. Amylin treatment also led to improvements in learning and memory in two AD mouse models. Mechanistic studies showed that an amylin receptor antagonist successfully antagonized some protective effects of amylin in vivo, suggesting that the protective effects of amylin require interaction with its cognate receptor. Comparison of signaling cascades emanating from AmR suggest that amylin electively suppresses activation of the CDK5 pathway by Aß. Treatment with amylin significantly reduced CDK5 signaling in a receptor dependent manner, dramatically decreasing the levels of p25, the active form of CDK5 with a corresponding reduction in tau phosphorylation. This is the first report documenting the ability of amylin treatment to reduce tauopathy and inflammation in animal models of AD. The data suggest that the clinical analog of amylin, pramlintide, might exhibit utility as a therapeutic agent for AD and other neurodegenerative diseases.

E4orf1 Enhances Glucose Uptake Independent of Proximal Insulin Signaling.

Impaired proximal insulin signaling is often present in diabetes. Hence, approaches to enhance glucose disposal independent of proximal insulin signaling are desirable. Evidence indicates that Adenovirus-derived E4orf1 protein may offer such an approach. This study determined if E4orf1 improves insulin sensitivity and downregulates proximal insulin signaling in vivo and enhances cellular glucose uptake independent of proximal insulin signaling in vitro. High fat fed mice were injected with a retrovirus plasmid expressing E4orf1, or a null vector. E4orf1 significantly improved insulin sensitivity in response to a glucose load. Yet, their proximal insulin signaling in fat depots was impaired, as indicated by reduced tyrosine phosphorylation of insulin receptor (IR), and significantly increased abundance of ectonucleotide pyrophosphatase/phosphodiesterase-1 (ENPP1). In 3T3-L1 pre-adipocytes E4orf1 expression impaired proximal insulin signaling. Whereas, treatment with rosiglitazone reduced ENPP1 abundance. Unaffected by IR-KD (insulin receptor knockdown) with siRNA, E4orf1 significantly up-regulated distal insulin signaling pathway and enhanced cellular glucose uptake. In vivo, E4orf1 impairs proximal insulin signaling in fat depots yet improves glycemic control. This is probably explained by the ability of E4orf1 to promote cellular glucose uptake independent of proximal insulin signaling. E4orf1 may provide a therapeutic template to enhance glucose disposal in the presence of impaired proximal insulin signaling.

An adenovirus-derived protein: A novel candidate for anti-diabetic drug development.

AIMS: Exposure to human adenovirus Ad36 is causatively and correlatively linked with better glycemic control in animals and humans, respectively. Although the anti-hyperglycemic property of Ad36 may offer some therapeutic potential, it is impractical to use an infectious agent for therapeutic benefit. Cell-based studies identified that Ad36 enhances cellular glucose disposal via its E4orf1 protein. Ability to improve glycemic control in vivo is a critical prerequisite for further investigating the therapeutic potential of E4orf1. Therefore, the aim of this study was to determine the ability of E4orf1 to improve glycemic control independent of insulin despite high fat diet. MATERIALS & METHODS: 8-9wk old male C57BL/6J mice fed a high-fat diet (60% kcal) were injected with a retrovirus plasmid expressing E4orf1, or a null vector (Control). Glycemic control was determined by glucose and insulin tolerance test. Islet cell size, amount of insulin and glucagon were determined in formalin-fixed pancreas. Rat insulinoma cell line (832/13) was infected with E4orf1 or control to determine changes in glucose stimulated insulin secretion. Protein from flash frozen adipose tissue depots, liver and muscle was used to determine molecular signaling by western blotting. RESULTS: In multiple experiments, retrovirus-mediated E4orf1 expression in C57BL/6J mice significantly and reproducibly improved glucose excursion following a glucose load despite a high fat diet (60% energy). Importantly, E4orf1 improved glucose clearance without increasing insulin sensitivity, production or secretion, underscoring its insulin-independent effect. E4orf1 modulated molecular signaling in mice tissue, which included greater protein abundance of adiponectin, p-AKT and Glucose transporter Glu4. CONCLUSIONS: This study provides the proof of concept for translational development of E4orf1 as a potential anti-diabetic agent. High fat intake and impaired insulin signaling are often associated with obesity, diabetes and insulin resistance. Hence, the ability of E4orf1 to improve glycemic control despite high fat diet and independent of insulin, is particularly attractive.

Human adenovirus Ad36 and its E4orf1 gene enhance cellular glucose uptake even in the presence of inflammatory cytokines.

BACKGROUND: Aging and obesity are associated with elevated pro-inflammatory cytokines such as monocyte chemoattractant protein (MCP)-1 and tumor necrosis factor (TNF)α, which are linked to insulin resistance. Anti-inflammatory agents have marginal effect in improving insulin resistance. Hence, agents are needed to improve glycemic control despite the inflammation. Ad36, a human adenovirus, increases TNFα and MCP1 mRNA in adipose tissue, yet improves glycemic control in mice. Ad36 via its E4orf1 gene, up-regulates AKT/glucose transporter (Glut)-4 signaling to enhance cellular glucose uptake. OBJECTIVE: Directly test a role of Ad36, or E4orf1 in enhancing cellular glucose uptake in presence of inflammatory cytokines. METHODS: Experiment 1: 3T3-L1 preadipocytes were treated with 0, 10 or 100 ng/mL lipopolysaccharides (LPS), and infected with 0 or 5 plaque forming units (PFU) of Ad36/cell. 3T3-L1 cells that stably and inducibly express E4orf1 or a null vector (pTRE-E4orf1 or pTRE-null cells), were similarly treated with LPS and then with doxycycline, to induce E4orf1. Experiment 2: 3T3L1 preadipocytes were treated with 25 nM MCP1 or 20 nM TNFα for 16 h, followed by infection with 0 or 5 PFU of Ad36/cell. Experiment 3: pTRE-E4orf1 or -null cells were similarly treated with MCP1 or TNFα followed by doxycycline to induce E4orf1. Cellular glucose uptake and cellular signaling were determined 72 h post-Ad36 infection or E4orf1-induction, in continued presence of MCP1 or TNFα. RESULTS: In 3T3-L1 preadipocytes, Ad36, but not E4orf1, increased MCP1 and TNFα mRNA, in presence of LPS stimulation. Ad36 or E4orf1 up-regulated AKT-phosphorylation and Glut4 and increased glucose uptake (P < 0.05) in the presence of MCP1 or TNFα. CONCLUSIONS: Unlike Ad36, E4orf1 does not appear to stimulate inflammatory response. Ad36 and E4orf1 both enhance cellular glucose uptake even in presence of inflammation. Further research is needed to harness this novel and beneficial property of E4orf1 to improve hyperglycemia despite chronic inflammation that is commonly present in aging and obesity.

Unbiased proteomic profiling strategy for discovery of bacterial effector proteins reveals that Salmonella protein PheA is a host cell cycle regulator.

Salmonella utilizes a type III secretion system to inject bacterial effector proteins into the host cell cytosol. Once in the cytosol, these effectors hijack various biochemical pathways to regulate virulence. Despite the importance of effector proteins, especially for understanding host-pathogen interactions, a potentially large number of effectors are yet to be identified. Here, we demonstrate that unbiased chemical proteomic profiling using off-the-shelf fluorescent probes leads to the discovery of a host cell cycle regulator encoded in the Salmonella genome. Our profiling combined with bioinformatic analysis implicates 29 Salmonella as potential effectors. We follow up on the top candidate, chorismate mutase-P/prehenate dehydratase, PheA, and present evidence that PheA is an effector that mimics E2F7 transcription factor of the host cell and promotes G1/S cell cycle arrest. This validates our strategy and opens opportunities for effector identification in the future.

Adenovirus 36 attenuates weight loss from exercise but improves glycemic control by increasing mitochondrial activity in the liver.

Human adenovirus type 36 (Ad36) as an obesity agent induces adiposity by increasing glucose uptake and promoting chronic inflammation in fat tissues; in contrast, exercise reduces total body fat and inflammation. Our objective was to determine the association between Ad36 and the effects of exercise on inflammation and glycemic control. In the human trials (n = 54), Korean children (aged 12-14 years) exercised for 60 min on three occasions each week for 2 months. We compared the body mass index (BMI) Z-scores before and after exercise. C57BL/6 mice were infected with Ad36 and Ad2 as a control, and these mice exercised for 12 weeks postinfection. After the exercise period, we determined the serum parameters and assessed the presence of inflammation and the mitochondrial function in the organs. Ad36-seropositive children who were subjected to a supervised exercise regimen had high BMI Z-scores whereas Ad36-seronegative children had lower scores. Similarly, Ad36-infected mice were resistant to weight loss and exhibited chronic inflammation of their adipose tissues despite frequent exercise. However, Ad36 combined with exercise reduced the levels of serum glucose, nonesterified fatty acids, total cholesterol, and insulin in virus-infected mice. Interestingly, virus infection increased the mitochondrial function in the liver, as demonstrated by the numbers of mitochondria, cytochrome c oxidase activity, and transcription of key mitochondrial genes. Therefore Ad36 counteracts the weight-loss effect of exercise and maintains the chronic inflammatory state, but glycemic control is improved by exercise synergistically because of increased mitochondrial activity in the liver.

Reduction of adenovirus 36-induced obesity and inflammation by mulberry extract.

Adenovirus 36 (Ad36) is known to be associated with human obesity and to trigger inflammation in murine models. However, to date no clinical drugs for treating virus-induced obesity have been developed. Therefore, in this study, the anti-obesity and anti-inflammation effects of mulberry extract on Ad36 were evaluated in mice. The mulberry extract-fed group showed a reduction in total body weight and in epidermal fat pads. A combination of various mulberry components (1-deoxynojirimycin, kuromanin chloride and resveratrol) and a mulberry extract prevented viral replication by 50% and 70%, respectively, compared with an untreated Ad36-infected group. Moreover, the extract decreased both concentrations of proinflammatory cytokines, such as MCP-1 and TNF-α, and the numbers of infiltrating immune cells and macrophages in epidermal fat pads. In conclusion, dietary mulberry extract might offer an avenue for the development of therapeutic approaches for treating or preventing virus-induced obesity and inflammation-related metabolic diseases.

Prophylactic and therapeutic vaccines for obesity.

Chronic diseases such as obesity and diabetes are major causes of death and disability throughout the world. Many causes are known to trigger these chronic diseases, and infectious agents such as viruses are also pathological factors. In particular, it is considered that adenovirus 36 infections may be associated with obesity. If this is the case, a vaccine against adenovirus 36 may be a form of prophylaxis to combat obesity. Other types of therapeutic vaccines to combat obesity are also being developed. Recently, hormones such as glucagon-like peptide-1, ghrelin, and peptide YY have been studied as treatments to prevent obesity. This review describes the ongoing development of therapeutic vaccines to treat obesity, and the possibility of using inactivated adenovirus 36 as a vaccine and an anti-obesity agent.

Immunogenicity and safety of H1N1 influenza hemagglutinin protein expressed in a baculovirus system.

Although most influenza vaccines are produced in eggs, new types of vaccines must be developed. In this study, the immunogenicity and safety of a baculovirus-expressed hemagglutinin (HA) of H1N1 influenza virus (Korea/01/2009; designated "HA-Bac-K") was compared with those of a commercially available baculovirus-expressed HA (designated "HA-Bac-C") and an Escherichia coli-expressed HA (designated "HA-E. Coli-K"). HA-Bac-K succeeded in inducing hemagglutination inhibition and neutralization antibodies in mouse and ferret models. The different immunogenicities observed may be attributable to the different expression systems and purification protocols used. Our work suggests that HA expressed in a baculovirus system is an effective and safe candidate influenza vaccine.

IK induced by coxsackievirus B3 infection transiently downregulates expression of MHC class II through increasing cAMP.

Major histocompatibility complex (MHC) class II expression is critical for the presentation of antigens in the immune response to viral infection. Consequently, some viruses regulate the MHC class II-mediated presentation of viral antigens as a mechanism of immune escape. In this study, we found that Coxsackievirus B3 (CVB3) infection transiently increased IK expression, which reduced the expression of MHC class II (I-A/I-E) on splenic B cells. Interestingly, CVB3-induced IK elevated cAMP, a downstream molecule of the G protein-coupled receptors, which inhibited MHC class II presentation on B cells. Transgenic mice expressing truncated IK showed lower expression of MHC class II on B cells than did wild-type mice after CVB3 infection. Taken together, these results imply that IK plays a role in downregulating MHC class II expression on B cells during CVB3 infection through the induction of cAMP.

Teaching and assessing endoscopic sinus surgery skills on a validated low-cost task trainer.

OBJECTIVES/HYPOTHESIS: To evaluate a previously validated low-cost sinus surgery task trainer as a means of acquiring basic endoscopic sinus surgery skills and as an objective structured assessment of technical skills (OSATS) to determine procedural competency. STUDY DESIGN: Prospective blinded study. METHODS: Medical students (N = 52) with no sinus surgery experience learned to perform nasal endoscopy and five specific sinus surgery tasks using the validated task trainer. Training included regimented expert instruction, peer instruction/observation, and experienced-based learning. Pre- and post-training video recordings of nasal endoscopy and five sinus surgery skills were obtained. Two blinded expert otolaryngologists compared pre- and post-training performance using a checklist and global rating scale. RESULTS: Medical student post-training performance was significantly better than pre-training performance for each checklist item and global rating scale as calculated by paired t test (P < .001). Interrater reliability and internal consistency were confirmed by Kendall's coefficient of concordance and Cronbach's α calculations, respectively. CONCLUSIONS: The sinus surgery task trainer provides an effective means of teaching and evaluating nasal endoscopy and basic sinus surgery skills for novice surgeons. With repeated practice, there was significant improvement in performance. An OSATS using the sinus surgery task trainer suggests that we can effectively measure endoscopic sinus surgery ability with the potential to reliably determine competency outside the operating room.