ILC3s control splenic cDC homeostasis via lymphotoxin signaling

The spleen contains a myriad of conventional dendritic cell (cDC) subsets that protect against systemic pathogen dissemination by bridging antigen detection to the induction of adaptive immunity. How cDC subsets differentiate in the splenic environment is poorly understood. Here, we report that LTα1β2-expressing Rorgt+ ILC3s, together with B cells, control the splenic cDC niche size and the terminal differentiation of Sirpα+CD4+Esam+ cDC2s, independently of the microbiota and of bone marrow pre-cDC output. Whereas the size of the splenic cDC niche depended on lymphotoxin signaling only during a restricted time frame, the homeostasis of Sirpα+CD4+Esam+ cDC2s required continuous lymphotoxin input. This latter property made Sirpα+CD4+Esam+ cDC2s uniquely susceptible to pharmacological interventions with LTβR agonists and antagonists and to ILC reconstitution strategies. Together, our findings demonstrate that LTα1β2-expressing Rorgt+ ILC3s drive splenic cDC differentiation and highlight the critical role of ILC3s as perpetual regulators of lymphoid tissue homeostasis.

Pathogenesis of Influenza A(H7N9) Virus in Aged Nonhuman Primates

The avian influenza A(H7N9) virus has caused high mortality rates in humans, especially in the elderly; however, little is known about the mechanistic basis for this. In the current study, we used nonhuman primates to evaluate the effect of aging on the pathogenicity of A(H7N9) virus. We observed that A(H7N9) virus infection of aged animals (defined as age 20-26 years) caused more severe symptoms than infection of young animals (defined as age 2-3 years). In aged animals, lung inflammation was weak and virus infection was sustained. Although cytokine and chemokine expression in the lungs of most aged animals was lower than that in the lungs of young animals, 1 aged animal showed severe symptoms and dysregulated proinflammatory cytokine and chemokine production. These results suggest that attenuated or dysregulated immune responses in aged animals are responsible for the severe symptoms observed among elderly patients infected with A(H7N9) virus.

Impact of radial compression protocols on the compression time and radial artery occlusion

Background

Trans-radial access (TRA) has been established as a safe and established approach for invasive coronary catheter procedures. However, protocols for post-procedural hemostasis varies depending on institutes and an evidence-based protocol is lacking.

Purpose

The objective of this study was to investigate the clinical implications of procedural hemostasis.

Methods

Consecutive patients who were referred to outpatient catheter examination before and after April 2018 were treated with an old and a new protocol, respectively. In both protocols, we used the same commercially available hemostasis band with injecting an air of 16 ml for hemostasis. In the old protocol, the amount and timing of deflation were fixed, whereas the air was removed as much as possible for every 30 minutes in the new protocol. Time to complete hemostasis, the rate of major bleeding, and the rate of radial artery occlusion (RAO) at 6 months after the catheter examination were compared between the protocols.

Results

Total of 1,843 (71±10 years old, 77% male) patients was included in the study. Between patients in the old and the new protocol group (n=1,000 and 843, respectively), there was no significant difference in age, gender, body size, or systolic blood pressure. The new group had significantly higher prevalence of diabetes (47% vs 39%, p=0.002), slightly larger sheath size (4.1±0.3 vs 4.0±0.2 Fr, p<0.001), and lower rate of dual antiplatelet therapy (DAPT: 24% vs. 35%, p<0.001). Time for complete hemostasis was about one-third with the new protocol compared with the old protocol (65±32 vs. 190±16 min, p<0.001) and there was no major bleeding in either group. The rate of radial artery occlusion was 0.7% and 9.8% in the old and the new group (p<0.001). Multivariate analysis showed that the significant predictor of prolonged hemostasis time were the old protocol (odds ratio: OR 80.5, p<0.001) and the prescription of DAPT (OR 2.9, p<0.001), while the factors associated with higher risk of radial occlusion were the old protocol (OR 13.9, p<0.001), the number of previous TRA (OR 1.1, p<0.001), and smaller body size (OR 0.127 per 1 m2 increase p=0.005).

Conclusions

Our new protocol for hemostasis after TRA was strongly associated with shorter hemostasis time and a lower rate of radial artery occlusion. This approach will decrease the post-procedural hospital time with even fewer complication rates.

Study outline

Funding Acknowledgement

Type of funding source: None

High Levels of miR-483-3p Are Present in Serum Exosomes Upon Infection of Mice With Highly Pathogenic Avian Influenza Virus

Exosomes, the extracellular vesicles that contain functional proteins and RNAs, regulate cell-cell communication. Recently, our group reported that levels of various microRNAs (miRNAs) in bronchoalveolar lavage fluid exosomes were highly increased in influenza virus-infected mice and that one of those miRNAs, miR-483-3p, was involved in the potentiation of the innate immune responses to influenza virus infection in mouse type II pneumocytes. Here, we evaluated exosomal miR-483-3p levels in the serum of influenza virus-infected mice and found that miR-483-3p levels were significantly increased during infection with a highly pathogenic avian H5N1 influenza virus. Moreover, miR-483-3p-enriched exosomes derived from type II pneumocytes potentiated the expression of proinflammatory cytokine genes in vascular endothelial cells. Our findings suggest that serum exosomal transfer of miR-483-3p might be involved in the inflammatory pathogenesis of H5N1 influenza virus infection.

Serological analysis of Ebola virus survivors and close contacts in Sierra Leone: A cross-sectional study

The 2013–2016 Ebola virus outbreak in West Africa was the largest and deadliest outbreak to date. Here we conducted a serological study to examine the antibody levels in survivors and the seroconversion in close contacts who took care of Ebola-infected individuals, but did not develop symptoms of Ebola virus disease. In March 2017, we collected blood samples from 481 individuals in Makeni, Sierra Leone: 214 survivors and 267 close contacts. Using commercial, quantitative ELISAs, we tested the plasma for IgG-specific antibodies against three major viral antigens: GP, the only viral glycoprotein expressed on the virus surface; NP, the most abundant viral protein; and VP40, a major structural protein of Zaire ebolavirus. We also determined neutralizing antibody titers. In the cohort of Ebola survivors, 97.7% of samples (209/214) had measurable antibody levels against GP, NP, and/or VP40. Of these positive samples, all but one had measurable neutralizing antibody titers against Ebola virus. For the close contacts, up to 12.7% (34/267) may have experienced a subclinical virus infection as indicated by detectable antibodies against GP. Further investigation is warranted to determine whether these close contacts truly experienced subclinical infections and whether these asymptomatic infections played a role in the dynamics of transmission.

As the causative agent of an often lethal hemorrhagic fever disease in humans and nonhuman primates, Zaire ebolavirus typically causes high fever, severe diarrhea, and vomiting which results in case fatality rates as high as 90%. The 2013–2016 outbreak in West Africa was the largest and most devastating Ebola outbreak to date resulting in over 28,600 identified human cases and 11,300 deaths. Though our knowledge of virus transmission is incomplete, we do know that transmission occurs through direct contact with virus-contaminated body fluids (blood, secretions, or other body fluids), materials such as bedding contaminated with these fluids, and through the handling and preparation of contaminated food. Asymptomatic Ebola virus infections that result in seroconversion in the absence of disease symptoms have been observed both in humans and experimentally in animal models. In the present serology study, we determined a majority of Ebola survivors in our cohort had measurable antibody levels against at least one viral antigen, as expected. In our cohort of close contacts, relatives and health care workers who took care of Ebola-infected individuals during the outbreak, we observed a rate of seroprevalence of 12.7% as indicated by detectable GP antibody levels. Given that Ebola virus is typically associated with a highly lethal disease in humans, it is of great interest to determine the host-virus interactions and transmission dynamics associated with asymptomatic cases.

Lung-Derived Exosomal miR-483-3p Regulates the Innate Immune Response to Influenza Virus Infection

Exosomes regulate cell-cell communication by transferring functional proteins and RNAs between cells. Here, to clarify the function of exosomes during influenza virus infection, we characterized lung-derived exosomal microRNAs (miRNAs). Among the detected miRNAs, miR-483-3p was present at high levels in bronchoalveolar lavage fluid (BALF) exosomes during infection of mice with various strains of influenza virus, and miR-483-3p transfection potentiated gene expression of type I interferon and proinflammatory cytokine upon viral infection of MLE-12 cells. RNF5, a regulator of the RIG-I signaling pathway, was identified as a target gene of miR-483-3p. Moreover, we found that CD81, another miR-483-3p target, functions as a negative regulator of RIG-I signaling in MLE-12 cells. Taken together, this study indicates that BALF exosomal miRNAs may mediate the antiviral and inflammatory response to influenza virus infection.

Periodontitis Is Associated with Chronic Obstructive Pulmonary Disease

Although they are known to share pathophysiological processes, the relationship between periodontitis and chronic obstructive pulmonary disease (COPD) is not fully understood. The aim of the present study was to test the hypothesis that periodontitis is associated with a greater risk of development of COPD, when smoking is taken into account. The analysis in a 5-y follow-up population-based cohort study was based on 900 community-dwelling Japanese adults (age: 68.8 ± 6.3 [mean ± SD], 46.0% male) without COPD aged 60 or older with at least 1 tooth. Participants were classified into 3 categories according to baseline periodontitis severity (no/mild, moderate, and severe). COPD was spirometrically determined by a fixed ratio of <0.7 for forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) and by FEV1/FVC below the lower limit of normal. Poisson regression was used to calculate the relative risk (RR) of developing COPD according to the severity of periodontitis. The population attributable fraction (PAF) was also calculated. During follow-up, 22 (2.4%) subjects developed COPD. Compared with no/mild periodontitis subjects, a significantly increased risk of COPD occurred among severe periodontitis subjects (RR = 3.55; 95% confidence interval [CI], 1.18 to 10.67), but no significant differences were observed between the no/mild and moderate categories (RR = 1.48; 95% CI, 0.56 to 3.90). After adjustment for potential confounders, including smoking intensity, the relationship between severe periodontitis and risk of COPD remained significant (RR = 3.51; 95% CI, 1.15 to 10.74). Likewise, there was a positive association of periodontitis severity with risk of COPD ( P for trend = 0.043). The PAF for COPD due to periodontitis was 22.6%. These data highlight the potential importance of periodontitis as a risk factor for COPD.

Intranasal immunization with phosphorylcholine suppresses allergic rhinitis in mice

OBJECTIVES/HYPOTHESIS

Intranasal immunization with phosphorylcholine (PC) is known to reduce immunoglobulin (Ig)E production. However, its effects on the occurrence of allergic rhinitis (AR) are unknown. This study was performed to evaluate the effects of PC-keyhole limpet hemocyanin (PC-KLH) and to examine the effects on the occurrence of AR in a murine model of AR.

STUDY DESIGN

In vivo study using an animal model.

METHODS

Forty-five female BALB/c mice were divided into three groups; those pretreated with intranasal administration of PC-KLH followed by intraperitoneal sensitization and nasal challenge with ovalbumin (OVA) (group A), those untreated with PC-KLH followed by sensitization and nasal challenge with OVA (group B), and those untreated with PC-KLH or OVA as controls (group C). Nasal symptoms, allergic inflammation in the nasal mucosa, OVA specific IgE production, and cytokine profile were compared among those three groups. Dendritic cells (DCs) were isolated from splenic cells and PC-KLH-stimulated interleukin (IL)-12p40 production was measured.

RESULTS

The mice pretreated with PC-KLH showed lower allergic nasal symptoms and inflammation compared to untreated mice. The levels of total IgE and OVA-specific IgE in serum, and IL-4 production by nasal and splenic CD4⁺ T cells were significantly reduced by PC-KLH pretreatment. Furthermore, IL-12p40 production by DCs was induced by PC-KLH in a dose-dependent manner.

CONCLUSIONS

Intranasal administration of PC-KLH suppressed allergic inflammation in nasal mucosa and antigen-specific IgE production by downregulating Th2-type immune response. Intranasal immunization with PC might be useful to prevent AR and upper airway bacterial infection.

LEVEL OF EVIDENCE

NA. Laryngoscope, 128:E234-E240, 2018.

Multi-platform 'Omics Analysis of Human Ebola Virus Disease Pathogenesis

The pathogenesis of human Ebola virus disease (EVD) is complex. EVD is characterized by high levels of virus replication and dissemination, dysregulated immune responses, extensive virus- and host-mediated tissue damage, and disordered coagulation. To clarify how host responses contribute to EVD pathophysiology, we performed multi-platform 'omics analysis of peripheral blood mononuclear cells and plasma from EVD patients. Our results indicate that EVD molecular signatures overlap with those of sepsis, imply that pancreatic enzymes contribute to tissue damage in fatal EVD, and suggest that Ebola virus infection may induce aberrant neutrophils whose activity could explain hallmarks of fatal EVD. Moreover, integrated biomarker prediction identified putative biomarkers from different data platforms that differentiated survivors and fatalities early after infection. This work reveals insight into EVD pathogenesis, suggests an effective approach for biomarker identification, and provides an important community resource for further analysis of human EVD severity.

A Highly Pathogenic Avian H7N9 Influenza Virus Isolated from A Human Is Lethal in Some Ferrets Infected via Respiratory Droplets

Low pathogenic H7N9 influenza viruses have recently evolved to become highly pathogenic, raising concerns of a pandemic, particularly if these viruses acquire efficient human-to-human transmissibility. We compared a low pathogenic H7N9 virus with a highly pathogenic isolate, and two of its variants that represent neuraminidase inhibitor-sensitive and -resistant subpopulations detected within the isolate. The highly pathogenic H7N9 viruses replicated efficiently in mice, ferrets, and/or nonhuman primates, and were more pathogenic in mice and ferrets than the low pathogenic H7N9 virus, with the exception of the neuraminidase inhibitor-resistant virus, which showed mild-to-moderate attenuation. All viruses transmitted among ferrets via respiratory droplets, and the neuraminidase-sensitive variant killed several of the infected and exposed animals. Neuraminidase inhibitors showed limited effectiveness against these viruses in vivo, but the viruses were susceptible to a polymerase inhibitor. These results suggest that the highly pathogenic H7N9 virus has pandemic potential and should be closely monitored.

Emergence of Oseltamivir-Resistant H7N9 Influenza Viruses in Immunosuppressed Cynomolgus Macaques

Antiviral compounds (eg, the neuraminidase inhibitor oseltamivir) are invaluable for the treatment of individuals infected with influenza A viruses of the H7N9 subtype (A[H7N9]), which have infected and killed hundreds of persons. However, oseltamivir treatment often leads to the emergence of resistant viruses in immunocompromised individuals. To better understand the emergence and properties of oseltamivir-resistant A(H7N9) viruses in immunosuppressed individuals, we infected immunosuppressed cynomolgus macaques with an A(H7N9) virus and treated them with oseltamivir. Disease severity and mortality were higher in immunosuppressed than in immunocompetent animals. Oseltamivir treatment at 2 different doses reduced A(H7N9) viral titers in infected animals, but even high-dose oseltamivir did not block viral replication sufficiently to suppress the emergence of resistant variants. Some resistant variants were not appreciably attenuated in cultured cells, but an oseltamivir-resistant A(H7N9) virus did not transmit among ferrets. These findings are useful for the control of A(H7N9) virus infections in clinical settings.

Development of compartment for studies on the growth of protein crystals in space

To clarify the growth mechanism of a protein crystal, it is essential to measure its growth rate with respect to the supersaturation. We developed a compartment (growth cell) for measuring the growth rate (<0.1 nm s(-1)) of the face of a protein crystal at a controlled supersaturation by interferometry over a period of half a year in space. The growth cell mainly consists of quartz glass, in which the growth solution and a seed crystal are enclosed by capillaries, the screw sample holder, and a helical insert. To avoid the destruction of the cell and the evaporation of the water from the solution inside the cell, we selected the materials for these components with care. The equipment was successfully used to examine the growth of a lysozyme crystal at a controlled supersaturation in space, where convection is negligible because of the microgravity environment, thereby advancing our understanding of the mechanism of protein crystal growth from solution. The technique used to develop the growth cell is useful not only for space experiments but also for kinetic studies of materials with very slow growth and dissolution rates (<10(-3) nm s(-1)).

Circulating avian influenza viruses closely related to the 1918 virus have pandemic potential

Wild birds harbor a large gene pool of influenza A viruses that have the potential to cause influenza pandemics. Foreseeing and understanding this potential is important for effective surveillance. Our phylogenetic and geographic analyses revealed the global prevalence of avian influenza virus genes whose proteins differ only a few amino acids from the 1918 pandemic influenza virus, suggesting that 1918-like pandemic viruses may emerge in the future. To assess this risk, we generated and characterized a virus composed of avian influenza viral segments with high homology to the 1918 virus. This virus exhibited pathogenicity in mice and ferrets higher than that in an authentic avian influenza virus. Further, acquisition of seven amino acid substitutions in the viral polymerases and the hemagglutinin surface glycoprotein conferred respiratory droplet transmission to the 1918-like avian virus in ferrets, demonstrating that contemporary avian influenza viruses with 1918 virus-like proteins may have pandemic potential.

An Ultrasensitive Mechanism Regulates Influenza Virus-Induced Inflammation

Influenza viruses present major challenges to public health, evident by the 2009 influenza pandemic. Highly pathogenic influenza virus infections generally coincide with early, high levels of inflammatory cytokines that some studies have suggested may be regulated in a strain-dependent manner. However, a comprehensive characterization of the complex dynamics of the inflammatory response induced by virulent influenza strains is lacking. Here, we applied gene co-expression and nonlinear regression analysis to time-course, microarray data developed from influenza-infected mouse lung to create mathematical models of the host inflammatory response. We found that the dynamics of inflammation-associated gene expression are regulated by an ultrasensitive-like mechanism in which low levels of virus induce minimal gene expression but expression is strongly induced once a threshold virus titer is exceeded. Cytokine assays confirmed that the production of several key inflammatory cytokines, such as interleukin 6 and monocyte chemotactic protein 1, exhibit ultrasensitive behavior. A systematic exploration of the pathways regulating the inflammatory-associated gene response suggests that the molecular origins of this ultrasensitive response mechanism lie within the branch of the Toll-like receptor pathway that regulates STAT1 phosphorylation. This study provides the first evidence of an ultrasensitive mechanism regulating influenza virus-induced inflammation in whole lungs and provides insight into how different virus strains can induce distinct temporal inflammation response profiles. The approach developed here should facilitate the construction of gene regulatory models of other infectious diseases.

Central Role of Core Binding Factor β2 in Mucosa-Associated Lymphoid Tissue Organogenesis in Mouse

Mucosa-associated lymphoid tissue (MALT) is a group of secondary and organized lymphoid tissue that develops at different mucosal surfaces. Peyer's patches (PPs), nasopharynx-associated lymphoid tissue (NALT), and tear duct-associated lymphoid tissue (TALT) are representative MALT in the small intestine, nasal cavity, and lacrimal sac, respectively. A recent study has shown that transcriptional regulators of core binding factor (Cbf) β2 and promotor-1-transcribed Runt-related transcription factor 1 (P1-Runx1) are required for the differentiation of CD3-CD4+CD45+ lymphoid tissue inducer (LTi) cells, which initiate and trigger the developmental program of PPs, but the involvement of this pathway in NALT and TALT development remains to be elucidated. Here we report that Cbfβ2 plays an essential role in NALT and TALT development by regulating LTi cell trafficking to the NALT and TALT anlagens. Cbfβ2 was expressed in LTi cells in all three types of MALT examined. Indeed, similar to the previous finding for PPs, we found that Cbfβ2-/- mice lacked NALT and TALT lymphoid structures. However, in contrast to PPs, NALT and TALT developed normally in the absence of P1-Runx1 or other Runx family members such as Runx2 and Runx3. LTi cells for NALT and TALT differentiated normally but did not accumulate in the respective lymphoid tissue anlagens in Cbfβ2-/- mice. These findings demonstrate that Cbfβ2 is a central regulator of the MALT developmental program, but the dependency of Runx proteins on the lymphoid tissue development would differ among PPs, NALT, and TALT.

Multi-spectral fluorescent reporter influenza viruses (Color-flu) as powerful tools for in vivo studies

Seasonal influenza A viruses cause annual epidemics of respiratory disease; highly pathogenic avian H5N1 and the recently emerged H7N9 viruses cause severe infections in humans, often with fatal outcomes. Although numerous studies have addressed the pathogenicity of influenza viruses, influenza pathogenesis remains incompletely understood. Here we generate influenza viruses expressing fluorescent proteins of different colours ('Color-flu' viruses) to facilitate the study of viral infection in in vivo models. On adaptation to mice, stable expression of the fluorescent proteins in infected animals allows their detection by different types of microscopy and by flow cytometry. We use this system to analyse the progression of viral spread in mouse lungs, for live imaging of virus-infected cells, and for differential gene expression studies in virus antigen-positive and virus antigen-negative live cells in the lungs of Color-flu-infected mice. Collectively, Color-flu viruses are powerful tools to analyse virus infections at the cellular level in vivo to better understand influenza pathogenesis.

Influenza virus-host interactome screen as a platform for antiviral drug development

Host factors required for viral replication are ideal drug targets because they are less likely than viral proteins to mutate under drug-mediated selective pressure. Although genome-wide screens have identified host proteins involved in influenza virus replication, limited mechanistic understanding of how these factors affect influenza has hindered potential drug development. We conducted a systematic analysis to identify and validate host factors that associate with influenza virus proteins and affect viral replication. After identifying over 1,000 host factors that coimmunoprecipitate with specific viral proteins, we generated a network of virus-host protein interactions based on the stage of the viral life cycle affected upon host factor downregulation. Using compounds that inhibit these host factors, we validated several proteins, notably Golgi-specific brefeldin A-resistant guanine nucleotide exchange factor 1 (GBF1) and JAK1, as potential antiviral drug targets. Thus, virus-host interactome screens are powerful strategies to identify targetable host factors and guide antiviral drug development.

[Information sources for causality assessment of health problems related to health foods and their usefulness]

Collecting adverse case reports suspected to be due to health foods and evaluation of the causality are important to secure safety, even if the causal relationship between health foods and reported health problem is uncertain. Case reports are mainly collected at three sites: public health centers, practical living information online network system(PIO-NET), and individual companies. The case reports from the three sources are not dealt with consistently. In this study, we investigated and characterized those case reports from the viewpoint of evaluating causality, using the causality association rating methods, namely, the dendritic and pointed methods, which we reported previously. Information in public health centers comprised 20 reports per year; approximately 40% were from health care providers and contained detailed medical data. PIO-NET information comprised 366 reports per year; 80% were self-reports from users, and few medical details were included. Company information covered 1,323 cases from 13 companies; more than 90% were from users and most of them were complaints. Case reports from public health centers and PIO-NET showed that the largerst number of victims were female aged >60, with allergy and gastrointestinal symptoms. When these case reports from the letter two sources were examined using the causality association rating systems, most were rated as "possible" and only a few were rated as "probable". As specific case reports from different information sources were examined in this study, we were able to identify several points that should be improved in our two rating methods. However, to ensure the safety of health foods, it will be necessary to collect a large number of high-quality case reports for evaluation by a suitable causality rating method, and to integrate those evaluated case reports into a single site.

Virulence-affecting amino acid changes in the PA protein of H7N9 influenza A viruses

Novel avian-origin influenza A(H7N9) viruses were first reported to infect humans in March 2013. To date, 143 human cases, including 45 deaths, have been recorded. By using sequence comparisons and phylogenetic and ancestral inference analyses, we identified several distinct amino acids in the A(H7N9) polymerase PA protein, some of which may be mammalian adapting. Mutant viruses possessing some of these amino acid changes, singly or in combination, were assessed for their polymerase activities and growth kinetics in mammalian and avian cells and for their virulence in mice. We identified several mutants that were slightly more virulent in mice than the wild-type A(H7N9) virus, A/Anhui/1/2013. These mutants also exhibited increased polymerase activity in human cells but not in avian cells. Our findings indicate that the PA protein of A(H7N9) viruses has several amino acid substitutions that are attenuating in mammals.

IMPORTANCE

Novel avian-origin influenza A(H7N9) viruses emerged in the spring of 2013. By using computational analyses of A(H7N9) viral sequences, we identified several amino acid changes in the polymerase PA protein, which we then assessed for their effects on viral replication in cultured cells and mice. We found that the PA proteins of A(H7N9) viruses possess several amino acid substitutions that cause attenuation in mammals.

Presence of keratin-specific antibody-forming cells in palatine tonsils of patients with pustulosis palmaris et plantaris (PPP) and its correlation with prognosis after tonsillectomy

CONCLUSION

Keratin-specific immune responses in tonsils may be associated with the pathogenesis of pustulosis palmaris et plantaris (PPP). Evaluation of keratin-specific immune responses in tonsils might be useful to predict the effectiveness of tonsillectomy for patients with PPP.

OBJECTIVES

The aim of the present study was to clarify the role of keratin-specific immune responses in the pathogenesis of PPP in tonsils. It has been reported that anti-keratin antibodies in serum were higher in patients with PPP and decreased after tonsillectomy, indicating that anti-keratin antibodies might be generated in tonsils.

METHODS

In order to demonstrate the presence of keratin-specific immune responses in tonsils, the numbers of keratin-specific antibody-forming cells (AFCs) in tonsillar and peripheral blood lymphocytes were examined by enzyme-linked immunospot assay. The prognosis of PPP was compared after tonsillectomy.

RESULTS

The numbers of keratin-specific IgM and IgG AFCs in tonsils and of IgG AFCs in peripheral blood were significantly increased in patients with PPP. The numbers of keratin-specific IgG AFCs in peripheral blood correlated positively with tonsil and serum IgG antibodies specific to keratin. Our data show that a good prognosis in patients with PPP depended on the numbers of keratin-specific IgG and IgM AFCs in peripheral blood and the levels of keratin-specific IgG antibodies in serum being significantly decreased 6 months after tonsillectomy.

A comprehensive map of the influenza A virus replication cycle

Background

Influenza is a common infectious disease caused by influenza viruses. Annual epidemics cause severe illnesses, deaths, and economic loss around the world. To better defend against influenza viral infection, it is essential to understand its mechanisms and associated host responses. Many studies have been conducted to elucidate these mechanisms, however, the overall picture remains incompletely understood. A systematic understanding of influenza viral infection in host cells is needed to facilitate the identification of influential host response mechanisms and potential drug targets.

Description

We constructed a comprehensive map of the influenza A virus (‘IAV’) life cycle (‘FluMap’) by undertaking a literature-based, manual curation approach. Based on information obtained from publicly available pathway databases, updated with literature-based information and input from expert virologists and immunologists, FluMap is currently composed of 960 factors (i.e., proteins, mRNAs etc.) and 456 reactions, and is annotated with ~500 papers and curation comments. In addition to detailing the type of molecular interactions, isolate/strain specific data are also available. The FluMap was built with the pathway editor CellDesigner in standard SBML (Systems Biology Markup Language) format and visualized as an SBGN (Systems Biology Graphical Notation) diagram. It is also available as a web service (online map) based on the iPathways+ system to enable community discussion by influenza researchers. We also demonstrate computational network analyses to identify targets using the FluMap.

Conclusion

The FluMap is a comprehensive pathway map that can serve as a graphically presented knowledge-base and as a platform to analyze functional interactions between IAV and host factors. Publicly available webtools will allow continuous updating to ensure the most reliable representation of the host-virus interaction network. The FluMap is available at http://www.influenza-x.org/flumap/.

Neural mechanisms mediating association of sympathetic activity and exploration in decision-making

The somatic marker hypothesis asserts that decision-making can be guided by feedback of bodily states to the brain. In line with this hypothesis, the present study tested whether sympathetic activity shows an association with a tonic dimension of decision-making, exploratory tendency represented by entropy in information theory, and further examined the neural mechanisms of the association. Twenty participants performed a stochastic reversal learning task that required decision-making in an unstable and uncertain situation. Regional cerebral blood flow was evaluated using (15)O-water positron emission tomography (PET), and cardiovascular indices and concentrations of catecholamine in peripheral blood were also measured, during the task. In reversal learning, increased epinephrine during the task positively correlated with larger entropy, indicating a greater tendency for exploration in decision-making. The increase of epinephrine also correlated with brain activity revealed by PET in the somatosensory cortices, anterior insula, dorsal anterior cingulate cortex, and the dorsal pons. This result is consistent with previously reported brain matrixes of representation of bodily states and interoception. In addition, activity of the anterior insula specifically correlated with entropy, suggesting possible mediation of this brain region between peripheral sympathetic arousal and exploration in decision-making. These findings shed a new light about a role of bodily states in decision-making and underlying neural mechanisms.

Corticosteroids plus long-acting β2-agonists prevent double-stranded RNA-induced upregulation of B7-H1 on airway epithelium

BACKGROUND

Airway viral infections provoke exacerbations of asthma and chronic obstructive pulmonary disease. B7-H1 is a costimulatory molecule that is implicated in an escape mechanism of viruses from host immune systems. This escape may be associated with the persistence of viral infection and lead to exacerbation of underlying diseases. We have shown that an analog of viral double-stranded RNA, polyinosinic-polycytidylic acid (poly IC), upregulated the expression of B7-H1 on airway epithelial cells, an effect which was corticosteroid-resistant. We investigated the effects of corticosteroids plus long-acting β(2)-agonists (LABAs; fluticasone/salmeterol or budesonide/formoterol) on the expression of B7-H1.

METHODS

BEAS-2B cells and primary airway epithelial cells were stimulated with poly IC or respiratory syncytial virus. The expression of B7-H1 was assessed by flow cytometry.

RESULTS

Poly IC upregulated the expression of B7-H1, which was suppressed by high-concentration corticosteroids but not by LABAs. The upregulation was suppressed by very low-concentration corticosteroids when used in combination with LABAs. Their combination also suppressed the virus-induced upregulation of B7-H1. Poly IC stimulation induced the nuclear translocation of nuclear factor ĸB (NF-ĸB). Inhibitors of NF-ĸB activation prevented the poly IC-induced upregulation of B7-H1. Low-concentration corticosteroids in combination with LABAs enhanced the de novo induction of IĸBα, the endogenous inhibitor of NF-ĸB activation.

CONCLUSIONS

Fluticasone/salmeterol or budesonide/formoterol attenuate the virus-associated upregulation of B7-H1 on airway epithelial cells via suppression of NF-ĸB activation.

Integrated network analysis reveals a novel role for the cell cycle in 2009 pandemic influenza virus-induced inflammation in macaque lungs

Background

Annually, influenza A viruses circulate the world causing wide-spread sickness, economic loss, and death. One way to better defend against influenza virus-induced disease may be to develop novel host-based therapies, targeted at mitigating viral pathogenesis through the management of virus-dysregulated host functions. However, mechanisms that govern aberrant host responses to influenza virus infection remain incompletely understood. We previously showed that the pandemic H1N1 virus influenza A/California/04/2009 (H1N1; CA04) has enhanced pathogenicity in the lungs of cynomolgus macaques relative to a seasonal influenza virus isolate (A/Kawasaki/UTK-4/2009 (H1N1; KUTK4)).

Results

Here, we used microarrays to identify host gene sequences that were highly differentially expressed (DE) in CA04-infected macaque lungs, and we employed a novel strategy – combining functional and pathway enrichment analyses, transcription factor binding site enrichment analysis and protein-protein interaction data – to create a CA04 differentially regulated host response network. This network describes enhanced viral RNA sensing, immune cell signaling and cell cycle arrest in CA04-infected lungs, and highlights a novel, putative role for the MYC-associated zinc finger (MAZ) transcription factor in regulating these processes.

Conclusions

Our findings suggest that the enhanced pathology is the result of a prolonged immune response, despite successful virus clearance. Most interesting, we identify a mechanism which normally suppresses immune cell signaling and inflammation is ineffective in the pH1N1 virus infection; a dyregulatory event also associated with arthritis. This dysregulation offers several opportunities for developing strain-independent, immunomodulatory therapies to protect against future pandemics.

A replication-incompetent virus possessing an uncleavable hemagglutinin as an influenza vaccine

Vaccination is one of the most effective measures to protect against influenza virus infection. Inactivated and live-attenuated influenza vaccines are available; however, their efficacy is suboptimal. To develop a safe and more immunogenic vaccine, we produced a novel replication-incompetent influenza virus that possesses uncleavable hemagglutinin (HA) and tested its vaccine potential. The uncleavable HA was engineered by substituting the arginine at the C-terminus of HA1 with threonine, which prevents cleavage of HA into its HA1 and HA2 subunits, preventing fusion between the host and viral membranes. Although this fusion-deficient HA influenza virus that possesses uncleavable HA (uncleavable HA virus) could undergo multiple cycles of replication in only wild-type HA-expressing cells, it could infect normal cells and express viral proteins in infected cells, but could not generate infectious virus from infected cells due to the uncleavable HA. When C57BL/6 mice were intranasally immunized with the uncleavable HA virus, influenza-specific IgG and IgA antibodies were detected in nasal wash and bronchoalveolar lavage samples and in serum. In addition, influenza-specific CD8(+) T cells accumulated in the lungs of these mice. Moreover, mice immunized with the uncleavable HA virus were protected against a challenge of lethal doses of influenza virus, unlike mice immunized with a formalin-inactivated virus. These findings demonstrate that this fusion-deficient virus, which possesses uncleavable HA, is a suitable influenza vaccine candidate.

The innate immune response to cytomegalovirus: the kick-start (170.1)

Like all herpesviruses, cytomegalovirus (CMV, a β-herpesvirus) persists for the lifetime of its host. Primary infection is sub-clinical in healthy individuals, but can cause serious disease when immunity is compromised or naïve. We have previously shown the initial type I Interferon (IFNαβ) produced by the splenic stroma within hours after mouse CMV (MCMV) infection is dependent on lymphotoxin (LT)-LTβR signaling. We now show it is splenic marginal zone (MZ) stromal cells that are initially infected by MCMV and produce this initial IFNαβ. This “first wave” of IFNαβ is critical to restrict MCMV production from the MZ stroma, inhibiting the earliest measurable viral burst by 100-1000 fold. NK cells are key controllers of MCMV in the first few days of infection, but their role in restricting this first burst of MCMV is unclear. Depleting NK cells revealed them to contribute to initial control of MCMV production from the MZ stroma. Additional studies revealed NK cells can mediate their earliest effector function(s) independently of both IFNαβ and Ly49H, a key NK activating receptor that binds the MCMV m157 protein. Strikingly, the levels of MCMV produced from MZ stroma at the earliest time measurable are the highest observed at any subsequent time point prior to immune control of MCMV. These results highlight the importance of both IFNαβ and NK cells in controlling initial MCMV replication and spread, establishing a baseline for MCMV production over the course of acute infection.

Implications of nasopharynx-associated lymphoid tissue (NALT) in the development of allergic responses in an allergic rhinitis mouse model

BACKGROUND

Nasopharynx-associated lymphoid tissue (NALT) serves as an important inductive site for mucosal immunity in the upper respiratory tract. Despite its importance in the mucosal immune system, little is known regarding the role of NALT in airway allergic immune responses. We aimed to elucidate the role of NALT in the induction of upper airway allergic responses in a mouse model.

METHODS

Inhibitor of DNA binding/differentiation 2 (Id2)(-/-) and Id2(+/-) mice was exposed to the ovalbumin (OVA)-induced allergic rhinitis model, because the former resulted in the NALT deficiency. The allergic parameters, such as allergic symptoms, serum OVA-specific immunoglobulin E (IgE) levels, eosinophil infiltration, and cytokine profiles in the nasal mucosa, were compared between Id2(-/-) and Id2(+/-) groups.

RESULTS

NALT-null, Id2(-/-) mice displayed significantly lower allergic responses compared with Id2(+/-) mice, as demonstrated by lower levels of allergic symptoms, serum OVA-specific IgE, eosinophilic infiltration, and local Th2 cytokine transcriptions. To determine which of two factors, that is, the absence of NALT or the alteration of immunocompetent cell populations caused by the Id2 deficiency, has a larger effect on the attenuated allergic immune responses in Id2(-/-) mice, lethally irradiated Id2(-/-) mice were engrafted with C57BL/6 wild-type bone marrow cells and showed still significantly lower allergic immune responses compared with equally treated Id2(+/-) mice. In addition, IgE class switch recombination-associated molecules, such as ε immunoglobulin heavy-chain germline gene transcript, ε mRNA, and activation-induced cytidine deaminase mRNA, were detected in NALT from OVA-sensitized wild-type mice.

CONCLUSION

These results show the critical role of NALT for the induction of allergic responses in the upper airway at least in part by means of class switching to IgE in situ.

Chronic stress modulates neural and cardiovascular responses during reversal learning

Animal studies have revealed that chronic stress shifts cognitive strategies from the flexible goal-directed action to the simple and rigid habit action. In addition, stress-induced atrophy in the prefrontal cortex and dorsomedial striatum which are involved in the goal-directed action and hypertrophy of the dorsolateral striatum which is critical for the habit action were parallel with the effects of chronic stress on behaviors. The present study tested whether these previous findings in animal studies are compatible in humans by analyzing effects of chronic stress on neural and cardiovascular responses, which are likely important for performing appropriate actions. Twenty healthy men exposed to low or high chronic job stress performed a stochastic reversal learning task, which required cognitive flexibility and the goal-directed action. Regional cerebral blood flow was evaluated during the task using (15)O-water positron emission tomography, and cardiovascular parameters such as blood pressure and heart rate were also measured. During the reversal learning task, whereas participants with low chronic job stress exhibited activity in the anterior caudate, as well as orbitofrontal cortex, ventrolateral prefrontal cortex, insula, and midbrain, which might be related to the goal-directed action, participants with high chronic job stress exhibited no activity in such brain regions. Furthermore, participants with high chronic job stress exhibited less reactivity in diastolic blood pressure, which might be mediated by anterior cingulate cortical activity. These findings, in line with previous studies, suggested that chronic job stress correlates with less activity in brain regions related to the goal-directed action, and insensitive physiological responses in humans.

Nitric oxide modulates TGF-beta-directive signals to suppress Foxp3+ regulatory T cell differentiation and potentiate Th1 development

TGF-β can induce Foxp3(+) inducible regulatory T cells (Treg) and also synergize with IL-6 and IL-4 to induce Th17 and Th9 cells. We now report that NO modulates TGF-β activity away from Treg but toward the Th1 lineage. NO potentiated Th1 differentiation in the presence of TGF-β in both IL-12-independent and -dependent fashions by augmenting IFN-γ-activated STAT-1 and T-bet. Differentiation into Treg, Th1, and Th17 lineages could be modulated by NO competing with other cofactors, such as IL-6 and retinoic acid. NO antagonized IL-6 to block TGF-β-directed Th17 differentiation, and together with IL-6, NO suppressed Treg development induced by TGF-β and retinoic acid. Furthermore, we show that physiologically produced NO from TNF and inducible NO synthase-producing dendritic cells can contribute to Th1 development predominating over Treg development through a synergistic activity induced when these cells cocluster with conventional dendritic cells presenting Ag to naive Th cells. This illustrates that NO is another cofactor allowing TGF-β to participate in development of multiple Th lineages and suggests a new mechanism by which NO, which is associated with protection against intracellular pathogens, might maintain effective Th1 immunity.

The airway antigen sampling system: respiratory M cells as an alternative gateway for inhaled antigens

In this study, we demonstrated a new airway Ag sampling site by analyzing tissue sections of the murine nasal passages. We revealed the presence of respiratory M cells, which had the ability to take up OVA and recombinant Salmonella typhimurium expressing GFP, in the turbinates covered with single-layer epithelium. These M cells were also capable of taking up respiratory pathogen group A Streptococcus after nasal challenge. Inhibitor of DNA binding/differentiation 2 (Id2)-deficient mice, which are deficient in lymphoid tissues, including nasopharynx-associated lymphoid tissue, had a similar frequency of M cell clusters in their nasal epithelia to that of their littermates, Id2(+/-) mice. The titers of Ag-specific Abs were as high in Id2(-/-) mice as in Id2(+/-) mice after nasal immunization with recombinant Salmonella-ToxC or group A Streptococcus, indicating that respiratory M cells were capable of sampling inhaled bacterial Ag to initiate an Ag-specific immune response. Taken together, these findings suggest that respiratory M cells act as a nasopharynx-associated lymphoid tissue-independent alternative gateway for Ag sampling and subsequent induction of Ag-specific immune responses in the upper respiratory tract.

Low Temperature Synthesis of Plasma Teos SiO2

In this study, we investigated the deposition temperature's affect on TEOS based Si02 properties and reaction mechanisms while changing the excitation frequency. We used a parallel-plate plasma reactor, and either 100 kHz or 13.56 MHz radio frequency to generate plasma. We found that 100 kHz plasma promotes SiO formation and improves the film properties at low deposition temperatures. We assume this to be due to the supplement of higher energy ions to the substrate surface in 100 kHz plasma. This in turn promotes the elimination reaction (condensation reaction) of OH that links to Si atoms as a terminator of surface SiO networks or precursor molecules.

HVEM-LIGHT interactions promote generation of memory Th2 cells that mediate lung inflammation (91.8)

Memory Th2 cells are important in the pathogenesis of allergic responses including asthma, orchestrating recruitment of eosinophils and other inflammatory cells. Members of the tumor necrosis factor (TNF) receptor superfamily have emerged as key contributors to T cell activity, and therefore we investigated whether the engagement of the herpesvirus entry mediator (HVEM) on T cells by the TNF family molecule LIGHT controls Th2 mediated lung inflammation. Using systems where either HVEM or LIGHT are only defective on responding antigen-specific T cells, we demonstrated that the presence of HVEM on T cells is indispensible for the generation and persistence of Th2 memory cells and for allergen-induced Th2 lung inflammation, despite having a limited effect on early Th2 effector responses. Using adoptive co-transfer experiments we demonstrate that HVEM-LIGHT interaction on CD4 T cells can support longevity of T cells and promote memory generation. We also observed reduced activity of protein kinase B (PKB/Akt) and NF-κB in HVEM-deficient effector CD4 T cells, correlating with their poor survival. Furthermore, expression of an active form of PKB in HVEM-deficient T cells rescued Th2 cell survival in vivo, and restored lung inflammation in recall responses. Collectively, our results demonstrate a critical role of HVEM signals in the pathogenesis of Th2 derived lung inflammation and suggest that blocking of HVEM-LIGHT interactions could be a novel therapeutic target for asthma

[A case of secondary pulmonary alveolar proteinosis associated with myelodysplastic syndrome, complicated with disseminated M. abscessus infection]

A 27-year-old man was admitted to our hospital complaining of a persistent high fever since August 2007. Chest radiography showed infiltration shadows in the right lower lung field. Chest CT revealed scattered small nodular shadows and patchy consolidations in the right lower lobe. He was diagnosed as secondary pulmonary alveolar proteinosis (sPAP) associated with myelodysplastic syndrome (MDS), confirmed by video-assisted thoracic surgery (VATS) and bone marrow aspiration. Sera were negative for anti-granulocyte-macrophage colony-stimulating factor (GM-CSF) autoantibody. He developed a subcutaneous abscess and meningitis caused by M. absessus after VATS. After a long-course of antibiotic therapy, an allogenic peripheral blood stem cell transplantation was performed. But he died of graft versus host disease and M. abscessus sepsis 87 days after transplantation.

T cell intrinsic heterodimeric complexes between HVEM and BTLA determine receptivity to the surrounding microenvironment

The inhibitory cosignaling pathway formed between the TNF receptor herpesvirus entry mediator (HVEM, TNFRSF14) and the Ig superfamily members, B and T lymphocyte attenuator (BTLA) and CD160, limits the activation of T cells. However, BTLA and CD160 can also serve as activating ligands for HVEM when presented in trans by adjacent cells, thus forming a bidirectional signaling pathway. BTLA and CD160 can directly activate the HVEM-dependent NF-kappaB RelA transcriptional complex raising the question of how NF-kappaB activation is repressed in naive T cells. In this study, we show BTLA interacts with HVEM in cis, forming a heterodimeric complex in naive T cells that inhibits HVEM-dependent NF-kappaB activation. The cis-interaction between HVEM and BTLA is the predominant form expressed on the surface of naive human and mouse T cells. The BTLA ectodomain acts as a competitive inhibitor blocking BTLA and CD160 from binding in trans to HVEM and initiating NF-kappaB activation. The TNF-related ligand, LIGHT (homologous to lymphotoxins, exhibits inducible expression, and competes with HSV glycoprotein D for HVEM, a receptor expressed by T lymphocytes, or TNFSF14) binds HVEM in the cis-complex, but NF-kappaB activation was attenuated, suggesting BTLA prevents oligomerization of HVEM in the cis-complex. Genetic deletion of BTLA or pharmacologic disruption of the HVEM-BTLA cis-complex in T cells promoted HVEM activation in trans. Interestingly, herpes simplex virus envelope glycoprotein D formed a cis-complex with HVEM, yet surprisingly, promoted the activation NF-kappaB RelA. We suggest that the HVEM-BTLA cis-complex competitively inhibits HVEM activation by ligands expressed in the surrounding microenvironment, thus helping maintain T cells in the naive state.

Id2-, RORgammat-, and LTbetaR-independent initiation of lymphoid organogenesis in ocular immunity

The eye is protected by the ocular immunosurveillance system. We show that tear duct–associated lymphoid tissue (TALT) is located in the mouse lacrimal sac and shares immunological characteristics with mucosa-associated lymphoid tissues (MALTs), including the presence of M cells and immunocompetent cells for antigen uptake and subsequent generation of mucosal immune responses against ocularly encountered antigens and bacteria such as Pseudomonas aeruginosa. Initiation of TALT genesis began postnatally; it occurred even in germ-free conditions and was independent of signaling through organogenesis regulators, including inhibitor of DNA binding/differentiation 2, retinoic acid–related orphan receptor γt, lymphotoxin (LT) α1β2–LTβR, and lymphoid chemokines (CCL19, CCL21, and CXCL13). Thus, TALT shares immunological features with MALT but has a distinct tissue genesis mechanism and plays a key role in ocular immunity.

LKB1 mutations in mucinous bronchioloalveolar carcinoma occurring in Peutz-Jeghers syndrome patients

11047

Background: Mutations in the gene encoding Liver Kinase B1, LKB1, are common in patients with Peutz-Jeghers syndrome (PJS), which is characterized by mucocutaneous pigmentation, intestinal polyps and a high incidence of cancers at variable sites (colorectal, gynecological, breast, pancreas, and lung). Although tumors occurring in PJS patients are known to contain mucin-rich conmponents, mucinous bronchioloalveolar carcinomas (mBACs) arising from the PJS background have only rarely been reported. Here we report two mBAC patients with PJS. We further explored the LKB1 gene in these two patients and, in addition, eight sporadic mBAC patients. Methods: Frozen tissue specimens were collected from ten mBAC patients who underwent surgery in our department from 2002 to 2008, and high molecular weight genomic DNA was extracted from them and stocked in the bio-bank. Written informed consent was obtained from each patient, and ethical approval was obtained from the IRB. The nucleotide sequence of LKB1 (EX01–09) was determined by genomic PCR-direct sequencing. Loss of heterozygosity (LOH) was analyzed by high resolution fluorescent microsatellite analysis (HRFMA) using two microsatellite markers that encompass the LKB1 locus, D19S886 and D19S565. Results: Among 11 tumors derived from the 10 patients, 9 distinct LKB1 mutations were found in 7 tumors (4 G:C to A:T transitions; 3 G:C to C:G transversions; 2 single nucleotide insetion/deletion). All of three tumors obtained from the two PJS patients harbored a same sequence alteration. Although LOH was not observed in these tumors, independent sequence alterations were found in two of the three tumors, which may suggest biallelic inactivation of LKB1 in tumors occurred in the PJS patients. Conclusions: The relatively high frequency of LKB1 mutation in mBAC patients may suggest its implication in lung carcinogenesis, at least in mBAC, and its potential as a therapeutic target.

[Table: see text]

No significant financial relationships to disclose.

Apparatus for material tests using an internal loading system in high-pressure gas at room temperature

A new type of apparatus for material tests using an internal loading system in high-pressure gas up to 100 MPa at room temperature without conventional material testing equipment was developed. The apparatus consists of a high-pressure control system and a pressure vessel, in which a piston is installed in the cylinder of the pressure vessel. The load caused by the pressure difference between spaces separated by the piston in the vessel cylinder is applied on the specimen connected to the piston in the vessel cylinder. The actual load on the specimen is directly measured by an external load cell and the displacement of the specimen is also measured by an external extensometer. As an example of the application of the apparatus, a tensile test on SUS316 stainless steel the Japanese Industrial Standard (JIS) G4303, which is comparable to the type 316 stainless steel ASTM A276, was conducted in 90 MPa hydrogen and argon. Hydrogen showed a marked effect on the tensile property of the material. The hydrogen gas embrittlement of the material was briefly discussed.

Regulatory role of lymphoid chemokine CCL19 and CCL21 in the control of allergic rhinitis

The lymphoid chemokines CCL19 and CCL21 are known to be crucial both for lymphoid cell trafficking and for the structural organization of lymphoid tissues such as nasopharynx-associated lymphoid tissue (NALT). However, their role in allergic responses remains unclear, and so our current study aims to shed light on the role of CCL19/CCL21 in the development of allergic rhinitis. After nasal challenge with OVA, OVA-sensitized plt (paucity of lymph node T cells) mice, which are deficient in CCL19/CCL21, showed more severe allergic symptoms than did identically treated wild-type mice. OVA-specific IgE production, eosinophil infiltration, and Th2 responses were enhanced in the upper airway of plt mice. Moreover, in plt mice, the number of CD4(+)CD25(+) regulatory T cells declined in the secondary lymphoid tissues, whereas the number of Th2-inducer-type CD8alpha(-)CD11b(+) myeloid dendritic cells (m-DCs) increased in cervical lymph nodes and NALT. Nasal administration of the plasmid-encoding DNA of CCL19 resulted in the reduction of m-DCs in the secondary lymphoid tissues and the suppression of allergic responses in plt mice. These results suggest that CCL19/CCL21 act as regulatory chemokines for the control of airway allergic disease and so may offer a new strategy for the control of allergic disease.

A novel M cell-specific carbohydrate-targeted mucosal vaccine effectively induces antigen-specific immune responses

Mucosally ingested and inhaled antigens are taken up by membranous or microfold cells (M cells) in the follicle-associated epithelium of Peyer's patches or nasopharynx-associated lymphoid tissue. We established a novel M cell–specific monoclonal antibody (mAb NKM 16–2-4) as a carrier for M cell–targeted mucosal vaccine. mAb NKM 16–2-4 also reacted with the recently discovered villous M cells, but not with epithelial cells or goblet cells. Oral administration of tetanus toxoid (TT)– or botulinum toxoid (BT)–conjugated NKM 16–2-4, together with the mucosal adjuvant cholera toxin, induced high-level, antigen-specific serum immunoglobulin (Ig) G and mucosal IgA responses. In addition, an oral vaccine formulation of BT-conjugated NKM 16–2-4 induced protective immunity against lethal challenge with botulinum toxin. An epitope analysis of NKM 16–2-4 revealed specificity to an α(1,2)-fucose–containing carbohydrate moiety, and reactivity was enhanced under sialic acid–lacking conditions. This suggests that NKM 16–2-4 distinguishes α(1,2)-fucosylated M cells from goblet cells containing abundant sialic acids neighboring the α(1,2) fucose moiety and from non-α(1,2)-fucosylated epithelial cells. The use of NKM 16–2-4 to target vaccine antigens to the M cell–specific carbohydrate moiety is a new strategy for developing highly effective mucosal vaccines.

Neuroregulator RET initiates Peyer's-patch tissue genesis

The tyrosine kinase receptor RET regulates the intestinal nervous system. A recent paper by Veiga-Fernandes et al. (2007) demonstrates that RET is also involved in the intestinal immune system through the initiation of Peyer's-patch tissue genesis.

Presence of Id2− and RORγt-independent lymphoid tissue organogenesis (81.2)

Id2 and RORγt have been shown to be the essential transcriptional regulators for the differentiation of CD3−CD4+CD45+ lymphoid tissue inducer cells (LTi). LTi migrate to the site of tissue genesis and provide the signal mediated by membrane-bound lymphotoxin (LT)α1β2, which results in the subsequent production of chemokines and adhesion molecules including CXCL13 and VCAM-1 by LTβR+ stromal cells. Organogenesis of lymphoid tissues such as Peyer’s patches are thus defective in Id2−/−, RORγt−/− and LTα−/− mice. Tear duct-associated lymphoid tissue (TALT) has been identified in human. However, the molecular and cellular requirements of TALT-genesis are totally unknown. Here we provide the first definitive evidence for the presence of Id2− and RORγt-independent tissue genesis program. We thus located the murine TALT in nasolacrimal duct and revealed that TALT-genesis did not require Id2, RORγt and LTα. TALT-genesis was initiated at postnatal days and developed in germ free and MyD88−/− mice. These results demonstrated that TALT has indeed developed using the unique pathway compared with other secondary lymphoid organs.

Different profiles of IL-10+IFN-gamma-IL-4-CD4+ T cells in the peripheral blood in atopic and non-atopic asthmatics

BACKGROUND

The impaired production of interleukin (IL) 10 from regulatory T cells has been proposed as a causal mechanism of asthma. Although IL-10-producing (IL-10+) T cells are detectable in the peripheral blood, their significance in the pathophysiology of asthma remains uncertain.

OBJECTIVES

This study aimed to investigate the profile of circulating IL-10+CD4+ T cells in atopic and non-atopic asthma.

METHODS

Atopic and non-atopic asthmatics were divided into a mild and severe group. Their peripheral blood mononuclear cells (PBMCs) were stimulated with anti-CD3 and anti-CD28 antibodies and then processed for triple cytokine flow cytometry directed to IL-10, interferon (IFN) gamma and IL-4.

RESULTS

IL-10+CD4+ cells were exclusively detected in the IFN-gamma-IL-4- population. In atopic asthma, the frequency of IL-10+IFN-gamma-IL-4-CD4+ cells in the severe group was significantly lower than that in the mild group. The frequency of IL-10+IFN-gamma-IL-4-CD4+ cells in the severe group was not significantly different from that in the mild group of those with non-atopic asthma. The frequency of IL-4+IFN-gamma-IL-10-CD4+ cells (Th2) was significantly higher in the group with mild atopic asthma than in that with mild non-atopic asthma. IFN-gamma+IL-4-IL-10-CD4+ cells (Th1) did not differ between groups, irrespective whether the subjects suffered from atopic or non-atopic asthma.

CONCLUSIONS

IL-10+CD4+ cells in PBMCs may be distinct from Th1 or Th2 and likely have the profile of regulatory T cells. The differential association of IL-10+IFN-gamma-IL-4-CD4+ cells with clinical severity between atopic and non-atopic asthma implies that its pathophysiological significance may differ among asthma phenotypes.

Intranasal immunization with phosphorylcholine induces antigen specific mucosal and systemic immune responses in mice

Phosphorylcholine (PC) is a structural component of a wide variety of pathogens including Streptococcus pneumoniae and Haemophilus influenzae, and anti-PC immune responses are known to protect mice against invasive bacterial diseases. The present study tested the capability of PC as an intranasal plurispecific vaccine against upper airway infections. BALB/c mice immunized with intranasal PC-keyhole limpet hemocyanin (KLH) plus cholera toxin (CT) as a mucosal adjuvant showed increased PC-specific IgM in serum, IgA in nasal wash and saliva, and numbers of PC-specific nasal and splenic antibody producing cells. Enhanced production of IL-4 and IFN-gamma by CD4+ T cells indicated the participation of Th2- and Th1-type cells. Salivary IgA antibodies produced by intranasal immunization with PC-KLH plus CT reacted to most strains of S. pneumoniae and H. influenzae. Further we demonstrated that the clearance of S. pneumoniae and H. influenzae from the nasal tract was significantly enhanced by nasal immunization with PC-KLH and CT. Thus, intranasal vaccination to induce PC-specific immune responses might help to prevent upper airway infections caused by S. pneumoniae and H. influenzae.

Cutting edge: Uniqueness of lymphoid chemokine requirement for the initiation and maturation of nasopharynx-associated lymphoid tissue organogenesis

CD3(-)CD4(+)CD45(+) inducer cells are required for the initiation of mucosa-associated organogenesis of both nasopharynx-associated lymphoid tissues (NALT) and Peyer's patches (PP) in the aerodigestive tract. CXCL13(-/-) mice and mice carrying the paucity of lymph node T cell (plt) mutation and lacking expression of CCL19 and CCL21 accumulate CD3(-)CD4(+)CD45(+) cells at the site of NALT but not of PP genesis. Although NALT was observed to develop in adult CXCL13(-/-) and plt/plt mice, the formation of germinal centers in CXCL13(-/-) mice was affected, and their population of B cells was much lower than in the NALT of CXCL13(+/-) mice. Similarly, fewer T cells were observed in the NALT of plt/plt mice than in control mice. These findings indicate that the initiation of NALT organogenesis is independent of CXCL13, CCL19, and CCL21. However, the expression of these lymphoid chemokines is essential for the maturation of NALT microarchitecture.