Chronic graft-versus-host disease. Part I: Epidemiology, pathogenesis, and clinical manifestations

Chronic graft-versus-host disease is a major complication of allogeneic hematopoietic cell transplantation and a leading cause of long-term morbidity, nonrelapse mortality, and impaired health-related quality of life. The skin is commonly affected and presents heterogeneously, making the role of dermatologists critical in both diagnosis and treatment. In addition, new clinical classification and grading schemes inform treatment algorithms, which now include 3 U.S. Food and Drug Administration-approved therapies, and evolving transplant techniques are changing disease epidemiology. Part I reviews the epidemiology, pathogenesis, clinical manifestations, and diagnosis of chronic graft-versus-host disease. Part II discusses disease grading and therapeutic management.

Chronic graft-versus-host disease. Part II: Disease activity grading and therapeutic management

Chronic graft-versus-host disease (cGVHD) is a major complication of allogeneic hematopoietic cell transplantation and a leading cause of long-term morbidity, nonrelapse mortality, and impaired health-related quality of life. The skin is commonly affected and presents heterogeneously, making the role of dermatologists critical in both diagnosis and treatment. In addition, new clinical classification and grading schemes inform treatment algorithms, which now include 3 Federal Drug Administration-approved therapies, and evolving transplant techniques are changing disease epidemiology. Part I reviews the epidemiology, pathogenesis, clinical manifestations, and diagnosis of cGVHD. Part II discusses disease grading and therapeutic management.

Metabolic syndrome prevalence and impact on outcomes in patients with chronic graft-versus-host disease

Patients with chronic graft-versus-host disease (cGVHD) are at heightened risk for components of metabolic syndrome (MetS), yet the prevalence and impact of MetS in the cGVHD patient population remain unknown. Adult patients (n = 229) with cGVHD enrolled in the cross-sectional NIH cGVHD Natural History Study (NCT00092235) were evaluated for MetS at enrollment and for variables associated with MetS. A majority (54.1%, 124/229) of the cohort met the diagnostic criteria for MetS. Patients with higher body mass index and lower performance status scores were more likely to have MetS (P < 0.0001; P = 0.026; respectively). Higher circulating erythrocyte sedimentation rate, C-reactive protein, and creatinine concentrations, along with lower estimated glomerular filtration rate, were associated with MetS (P < 0.001; P < 0.004; P = 0.02; P = 0.002; respectively). Patients with MetS compared to patients without MetS had no statistical differences in survival or NRM (5-year OS: 64% [95% CI: 54.8-71.8%] vs. 75.1% [95% CI: 65.6-82.3%]; respectively; overall P = 0.20; 5-year NRM: 21.7% [95% CI: 13.6-30.9%] vs. 10.1% [95% CI: 4.4-18.7%]; respectively; overall P = 0.12). Additionally, there was no difference in cGVHD severity between the two groups. Given the high prevalence of MetS in this cohort, clinicians should screen for its presence before it develops into comorbidities that complicate the course of cGVHD treatment.

Predictors and significance of kidney dysfunction in patients with chronic graft-versus-host disease

Kidney complications have been studied in allogeneic hematopoietic stem cell transplant patients but not specifically among chronic graft-versus-host disease (cGVHD) patients. Participants (n = 365) enrolled in the cross-sectional cGVHD natural history study (NCT00092235) were assessed for kidney dysfunction and overall survival. Kidney dysfunction was analyzed for associations in univariate and multivariable analyses. Kidney dysfunction (eGFR < 60) was found in 64 patients, and 29 patients had moderate-severe kidney dysfunction (eGFR < 45). Patients with kidney dysfunction were more likely treated with cyclosporine at evaluation or to have received it for GVHD prophylaxis, or prior treatment of GVHD. Patients with kidney dysfunction were less severely affected by cGVHD of skin, mouth, and joints/fascia. In multivariable modeling, history of cyclosporine use (OR = 2.19, 95% CI 1.13-4.25), angiotensin receptor blocker use (OR = 5.57, 95% CI 1.49-20.84), proteinuria (OR = 2.39, 95% CI 1.19-4.79), lower CRP (OR = 0.95, 95% CI 0.91-0.99), lower C3 (OR = 0.98, 95% CI 0.97-0.99), and lower hemoglobin (OR = 0.70, 95% CI 0.58-0.84) were jointly associated with kidney dysfunction. Overall survival was lower in those with moderate-severe kidney dysfunction (p = 0.015), demonstrating the importance of addressing kidney dysfunction in this population. The association of kidney dysfunction with less severe cGVHD suggests an etiology unrelated to cGVHD but potentially a consequence of drug-related toxicities.

World Workshop on Oral Medicine VII: Oral adverse effects to biologic agents in patients with inflammatory disorders. A scoping review

BACKGROUND

Biologic agents are rapidly emerging as an effective therapy to treat autoimmune and other chronic diseases. The use of these agents is poorly characterized, resulting in a lack of guidance for dental practitioners. Case reports of oral adverse events have begun to emerge. However, their scope and frequency have not been summarized and analysed to date. The objective of this review was to characterize the literature on oral adverse effects associated with biological therapy when used for autoimmune and inflammatory disorders.

METHODS

This review was developed in accordance with scoping review recommendations. Search strategies were developed and employed for six databases. Studies were selected using a systematic search process but with broad inclusion of study types given the paucity of information available. Reports of oral adverse events were analysed descriptively according to agent, mechanism of action, underlying disease, and oral adverse effect observed.

RESULTS

Our search returned 2080 articles and 51 met our inclusion criteria, of which most were case reports. The most frequent adverse effects included angioedema, oral lichenoid lesions, osteonecrosis of the jaw, and oral infections. There were also cases of oral malignancies associated with use of biologic agents. Less common effects such as pigmentation were also described.

CONCLUSIONS

Oral adverse events have been reported in patients on biologic therapy, albeit in small numbers to date. This limits the generalizability of these results, which should not be used to generate a clinical guideline as they are based primarily on case reports. However, this study presents the first review characterizing the adverse effects observed. Large multi-center studies will be necessary to further define the oral and dental complications caused by biologic agents.

Pernio and early SARS-CoV-2 variants: natural history of a prospective cohort and the role of interferon

Cases of new-onset pernio and recurrences in our cohort align tightly with trends in mean 7-day COVID-19 positivity in Wisconsin and mean temperature in Madison, Wisconsin by month.

Multicenter analysis of neutrophil extracellular trap dysregulation in adult and pediatric COVID-19

Dysregulation in neutrophil extracellular trap (NET) formation and degradation may play a role in the pathogenesis and severity of COVID-19; however, its role in the pediatric manifestations of this disease, including multisystem inflammatory syndrome in children (MIS-C) and chilblain-like lesions (CLLs), otherwise known as “COVID toes,” remains unclear. Studying multinational cohorts, we found that, in CLLs, NETs were significantly increased in serum and skin. There was geographic variability in the prevalence of increased NETs in MIS-C, in association with disease severity. MIS-C and CLL serum samples displayed decreased NET degradation ability, in association with C1q and G-actin or anti-NET antibodies, respectively, but not with genetic variants of DNases. In adult COVID-19, persistent elevations in NETs after disease diagnosis were detected but did not occur in asymptomatic infection. COVID-19–affected adults displayed significant prevalence of impaired NET degradation, in association with anti-DNase1L3, G-actin, and specific disease manifestations, but not with genetic variants of DNases. NETs were detected in many organs of adult patients who died from COVID-19 complications. Infection with the Omicron variant was associated with decreased NET levels when compared with other SARS-CoV-2 strains. These data support a role for NETs in the pathogenesis and severity of COVID-19 in pediatric and adult patients.

Pathogenic Tissue-Resident Memory T Cells in Exocrine Gland Chronic Graft-Versus-Host Disease

Salivary glands are frequently affected in chronic graft-versus-host disease (cGVHD), an autoimmune-like disease that occurs after allogeneic hematopoietic stem cell transplant resulting in tissue sclerosis and gland dysfunction. Alloreactive T cells have been identified as disease drivers, yet the function/pathogenicity of tissue-resident memory cells (Trm) in target organs remain unclear. In this study, we examined glandular Trm populations and tissue-specific signals that regulate Trm differentiation and functionality. scRNAseq analysis of human labial minor salivary glands (MSG) revealed enrichment of immune cell clusters in MSG of oral cGVHD patients. Focusing on T CD8 cells, we identified 4 clusters, one of them unique to affected patients which had low expression of CD69, but expressed other markers of Trm, including CD103, BLIMP1 and PD1. Additionally, this cluster was enriched for genes associated with cytotoxicity (IFNG, PRF1 and GZMB) and exhaustion (TIM3, LAG3 and TIGIT). Interestingly, this population showed high expression of CXCR6 and ligand-receptor analysis predicted CXCL16 an important signaling ligand that targets T CD8 cells. Further analysis implicates macrophages as the main source of CXCL16, suggesting their role in local accumulation of CXCR6+ Trm in the gland. Flow cytometry confirmed increased number of CD69+CD103±CD8+ Trm cells in cGVHD patients. Lymphocytic infiltration in MSG using IHC, spatially related the elevated frequency of CD8+IFNg+ T cells within interacinar stroma and damaged acini. The importance of Trm in site-specific cGVHD still needs further investigation. Based on current data, site-specific Trm cells may represent a druggable target in the therapy of refractory local cGVHD.

Supported by NIDCR (1ZIADE000747-05)

A mesenchymal to epithelial switch in Fgf10 expression specifies an evolutionary-conserved population of ionocytes in salivary glands

Fibroblast growth factor 10 (FGF10) is well established as a mesenchyme-derived growth factor and a critical regulator of fetal organ development in mice and humans. Using a single-cell RNA sequencing (RNA-seq) atlas of salivary gland (SG) and a tamoxifen inducible Fgf10^CreERT2:R26-tdTomato mouse, we show that FGF10^pos cells are exclusively mesenchymal until postnatal day 5 (P5) but, after P7, there is a switch in expression and only epithelial FGF10^pos cells are observed after P15. Further RNA-seq analysis of sorted mesenchymal and epithelial FGF10^pos cells shows that the epithelial FGF10^pos population express the hallmarks of ancient ionocyte signature Forkhead box i1 and 2 (Foxi1, Foxi2), Achaete-scute homolog 3 (Ascl3), and the cystic fibrosis transmembrane conductance regulator (Cftr). We propose that epithelial FGF10^pos cells are specialized SG ionocytes located in ducts and important for the ionic modification of saliva. In addition, they maintain FGF10-dependent gland homeostasis via communication with FGFR2b^pos ductal and myoepithelial cells.

Mauduit et al. identified unique FGF10-expressing ionocytes in salivary glands. FGF10 expression shifts from fibroblasts to epithelial ionocytes during postnatal development. Ionocytes play a dual role in salivary gland homeostasis; they maintain specific ion composition in saliva and act as niche cells, providing growth factor support for other epithelial cells.

Multicenter analysis of neutrophil extracellular trap dysregulation in adult and pediatric COVID-19

Dysregulation in neutrophil extracellular trap (NET) formation and degradation may play a role in the pathogenesis and severity of COVID-19; however, its role in the pediatric manifestations of this disease including MIS-C and chilblain-like lesions (CLL), otherwise known as "COVID toes", remains unclear. Studying multinational cohorts, we found that, in CLL, NETs were significantly increased in serum and skin. There was geographic variability in the prevalence of increased NETs in MIS-C, in association with disease severity. MIS-C and CLL serum samples displayed decreased NET degradation ability, in association with C1q and G-actin or anti-NET antibodies, respectively, but not with genetic variants of DNases. In adult COVID-19, persistent elevations in NETs post-disease diagnosis were detected but did not occur in asymptomatic infection. COVID-19-affected adults displayed significant prevalence of impaired NET degradation, in association with anti-DNase1L3, G-actin, and specific disease manifestations, but not with genetic variants of DNases. NETs were detected in many organs of adult patients who died from COVID-19 complications. Infection with the Omicron variant was associated with decreased levels of NETs when compared to other SARS-CoV-2 strains. These data support a role for NETs in the pathogenesis and severity of COVID-19 in pediatric and adult patients.

Summary

NET formation and degradation are dysregulated in pediatric and symptomatic adult patients with various complications of COVID-19, in association with disease severity. NET degradation impairments are multifactorial and associated with natural inhibitors of DNase 1, G-actin and anti-DNase1L3 and anti-NET antibodies. Infection with the Omicron variant is associated with decreased levels of NETs when compared to other SARS-CoV-2 strains.

Atto 465 Derivative Is a Nuclear Stain with Unique Excitation and Emission Spectra Useful for Multiplex Immunofluorescence Histochemistry

Multiplex immunofluorescence (mIF) is an effective technique for the maximal visualization of multiple target proteins in situ. This powerful tool is mainly limited by the spectral overlap of the currently available synthetic fluorescent dyes. The fluorescence excitation wavelengths ranging between 405 and 488 nm are rarely used in mIF imaging and serve as a logical additional slot for a fluorescent probe. In the present study, we demonstrate that the addition of 2,3,4,5,6-pentafluoroaniline to Atto 465 NHS ester, creating Atto 465-pentafluoroaniline (Atto 465-p), generates a bright nuclear stain in the violet-blue region of the visible spectrum. This allows the 405 nm excitation and emission, classically used for nuclear counterstains, to be used for the detection of another target protein. This increases the flexibility of the mIF panel and, with appropriate staining and microscopy, enables the quantitative analysis of at least six targets in one tissue section. (J Histochem Cytochem XX: XXX-XXX, XXXX).

Salivary ZG16B expression loss follows exocrine gland dysfunction related to oral chronic graft-versus-host disease

Chronic graft-versus-host disease (cGVHD) targets include the oral mucosa and salivary glands after allogeneic hematopoietic stem cell transplant (HSCT). Without incisional biopsy, no diagnostic test exists to confirm oral cGVHD. Consequently, therapy is often withheld until severe manifestations develop. This proteomic study examined saliva and human salivary gland for a biomarker profile at first onset of oral cGVHD prior to initiation of topical steroid therapy. Whole saliva collected at onset of biopsy-proven oral GVHD was assessed using liquid chromatography–coupled tandem mass spectrometry with identification of 569 proteins, of which 77 significantly changed in abundance. ZG16B, a secretory lectin protein, was reduced 2-fold in oral cGVHD saliva (p <0.05), and significantly decreased in salivary gland secretory cells affected by cGVHD. Single-cell RNA-seq analysis of healthy MSG localized ZG16B expression to two discrete acinar cell populations. Reduced ZG16B expression may indicate specific cGVHD activity and possibly general salivary gland dysfunction.

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Salivary glands are targets of chronic graft-versus-host disease (cGVHD)

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Saliva and salivary glands at onset of oral cGVHD have reduced ZG16B protein

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ZG16b gene expression localizes to two types of salivary gland excretory cells

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ZG16B expression loss may indicate cGVHD activity or general salivary gland damage

From Your Nose to Your Toes: A Review of Severe Acute Respiratory Syndrome Coronavirus 2 Pandemic‒Associated Pernio

Despite thousands of reported patients with pandemic-associated pernio, low rates of seroconversion and PCR positivity have defied causative linkage to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Pernio in uninfected children is associated with monogenic disorders of excessive IFN-1 immunity, whereas severe COVID-19 pneumonia can result from insufficient IFN-1. Moreover, SARS-CoV-2 spike protein and robust IFN-1 response are seen in the skin of patients with pandemic-associated pernio, suggesting an excessive innate immune skin response to SARS-CoV-2. Understanding the pathophysiology of this phenomenon may elucidate the host mechanisms that drive a resilient immune response to SARS-CoV-2 and could produce relevant therapeutic targets.

Subsequent Cancers in Patients Affected with Moderate or Severe Chronic Graft-versus-Host Disease

Subsequent cancer (SC) is a significant cause of morbidity and mortality in long-term survivors after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Chronic graft-versus-host disease (cGVHD) and treatment-related immunosuppression have been recognized as risk factors for SC. This study sought to investigate the incidence and risk factors for SC in patients with established cGVHD, assessed separately for onset of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC)-categorized into nonmelanoma skin cancer (NMSC)-and all cancers other than NMSC. Two hundred and four patients were enrolled in the prospective cross-sectional cGVHD Natural History Study and underwent comprehensive clinical evaluation. Patients were followed-up with an annual survey. The cumulative incidences of NMSC and cancers other than NMSC with competing risks were estimated separately, and transplantation- and cGVHD-related factors were assessed for association with outcomes using Gray's test and multivariable Cox models. The time period for all analyses began at 2 years postevaluation to restrict analyses to patients presumed to not have had SC present at evaluation. Nineteen patients were diagnosed with NMSC and 19 were diagnosed with cancers other than NMSC, with 10-year cumulative incidences of 15.5% (95% confidence interval, 9.0% to 27.6%) and 13.8% (95% CI, 8.2% to 20.8%), respectively. Age at transplantation (hazard ratio [HR], 1.94; 95% CI, 1.23 to 3.06) and higher C-reactive protein level at evaluation (HR, 9.49; 95% CI, 1.26 to 71.58) were jointly associated with NMSC, and gastrointestinal cGVHD at evaluation (HR, 0.26; 95% CI, 0.09 to 0.78) was associated with reduced risk of NMSC. T cell depletion at transplantation (HR, 3.09; 95% CI, 1.17 to 8.20), lymphoma as an indication for transplantation (HR, 3.96; 95% CI, 1.56 to 10.05), and oral cGVHD severity at evaluation (HR, 4.36; 95% CI, 1.52 to 12.46) were jointly associated with cancers other than NMSC. This study estimates the incidence of SC in a population of allo-HSCT recipients with severe cGVHD and identifies correlations with the subsequent development of SC. These factors seem to differ between NMSC and cancers other than NMSC. Further longitudinal investigations accounting for dynamic and cumulative processes are needed to improve our understanding and management of SC.

HPV32-related Heck's disease in a chronic graft-versus-host disease patient with long-term successful KTP laser treatment: A rare case report

We recently identified and treated a rare case of oral focal epithelial hyperplasia (FEH) in an adult patient with chronic graft-vs-host disease. This is the first report linking KTP laser therapy to successful long-term treatment HPV32 FEH.

National Institutes of Health Consensus Development Project on Criteria for Clinical Trials in Chronic Graft-versus-Host Disease: I. The 2020 Etiology and Prevention Working Group Report

Preventing chronic graft-versus-host disease (GVHD) remains challenging because the unique cellular and molecular pathways that incite chronic GVHD are poorly understood. One major point of intervention for potential prevention of chronic GVHD occurs at the time of transplantation when acute donor anti-recipient immune responses first set the events in motion that result in chronic GVHD. After transplantation, additional insults causing tissue injury can incite aberrant immune responses and loss of tolerance, further contributing to chronic GVHD. Points of intervention are actively being identified so that chronic GVHD initiation pathways can be targeted without affecting immune function. The major objective in the field is to continue basic studies and to translate what is learned about etiopathology to develop targeted prevention strategies that decrease the risk of morbid chronic GVHD without increasing the risks of cancer relapse or infection. Development of strategies to predict the risk of developing debilitating or deadly chronic GVHD is a high research priority. This working group recommends further interrogation into the mechanisms underpinning chronic GVHD development, and we highlight considerations for future trial design in prevention trials.

Oral Complications of Chronic Graft-Versus-Host Disease

The increasing clinical indications for hematopoietic stem cell transplantation (HSCT) and improved clinical care throughout and following HSCT have led to not only long-term survival but also to an increasing incidence and prevalence of graft-versus-host disease (GVHD). Chronic GVHD (cGVHD) affects almost 50% of adult patients post-HSCT, with increasing incidence in pediatric patients as well. Oral cGVHD specifically has a reported prevalence ranging from 45% to 83% in patients who develop cGVHD and is more extensive in adult patients than in children. Oral cGVHD affects patients through clinically significant oral symptoms that may lead to significantly decreased caloric intake, oral infections, and increased health service utilization, and may thus affect overall health and survival. The most commonly used therapy for mucosal involvement of oral cGVHD is topical high-dose and ultra-high potency corticosteroids, and calcineurin inhibitors. This review of oral complications of cGVHD presents the clinical significance of oral cGVHD to HSCT survivors, our current understanding of the pathobiology of oral cGVHD and gaps in this evidence, and the global targeted interdisciplinary clinical research efforts, including the National Institutes of Health Consensus Development Project on Criteria for Clinical Trials in Chronic Graft-versus-Host Disease. Current challenges regarding the management of oral cGVHD and strategies to advance our scientific understanding of this clinically significant chronic oral disease are presented.

World Workshop of Oral Medicine VII: A systematic review of immunobiologic therapy for oral manifestations of pemphigoid and pemphigus

OBJECTIVE

To assess the evidence for treatment of oral involvement of pemphigus and pemphigoid with biologics.

STUDY DESIGN

This systematic review used a comprehensive search strategy to identify literature describing oral involvement of pemphigus or pemphigoid treated with a biologic agent. The primary outcome measures were efficacy and safety of biologic therapy.

RESULTS

Inclusion criteria were met by 154 studies including over 1200 patients. Treatment of pemphigus with a total of 11 unique biologic agents and 3 unique combinations of agents is reported. Five randomized controlled trials (RCT) were included in the final analysis that investigated infliximab, IVIg, rituximab, and autologous platelet-rich plasma therapy for pemphigus vulgaris. Three non-RCT studies reported on successful rituximab or IVIg therapy for mucous membrane pemphigoid. Studies demonstrated considerable heterogeneity in agent, methods, and quality.

CONCLUSIONS

Evidence clearly describing oral tissue response to biologic therapy is sparse. Two RCTs support use of rituximab, one supports use of IVIg, and one pilot study suggests intralesional injection of autologous platelet-rich plasma aids healing of oral PV lesions. As oral lesions of pemphigus and pemphigoid can be refractory to systemic therapy, drug trials including biologic therapies should document details regarding response of the oral lesions to therapy.

Epithelial Cell Lineage and Signaling in Murine Salivary Glands

Maintaining salivary gland function is critical for oral health. Loss of saliva is a common side effect of therapeutic irradiation for head and neck cancer or autoimmune diseases such as Sjögren's syndrome. There is no curative treatment, and current strategies proposed for functional regeneration include gene therapy to reengineer surviving salivary gland tissue, cell-based transplant therapy, use of bioengineered glands, and development of drugs/biologics to stimulate in vivo regeneration or increase secretion. Understanding the genetic and cellular mechanisms required for development and homeostasis of adult glands is essential to the success of these proposed treatments. Recent advances in genetic lineage tracing provide insight into epithelial lineage relationships during murine salivary gland development. During early fetal gland development, epithelial cells expressing keratin 14 (K14) Sox2, Sox9, Sox10, and Trp63 give rise to all adult epithelium, but as development proceeds, lineage restriction occurs, resulting in separate lineages of myoepithelial, ductal, and acinar cells in postnatal glands. Several niche signals have been identified that regulate epithelial development and lineage restriction. Fibroblast growth factor signaling is essential for gland development, and other important factors that influence epithelial patterning and maturation include the Wnt, Hedgehog, retinoic acid, and Hippo signaling pathways. In addition, other cell types in the local microenvironment, such as endothelial and neuronal cells, can influence epithelial development. Emerging evidence also suggests that specific epithelial cells will respond to different types of salivary gland damage, depending on the cause and severity of damage and the resulting damaged microenvironment. Understanding how regeneration occurs and which cell types are affected, as well as which signaling factors drive cell lineage decisions, provides specific targets to manipulate cell fate and improve regeneration. Taken together, these recent advances in understanding cell lineages and the signaling factors that drive cell fate changes provide a guide to develop novel regenerative treatments.

World Workshop on Oral Medicine VII: Immunobiologics for salivary gland disease in Sjögren's syndrome: A systematic review

OBJECTIVE

This systematic review evaluated the efficacy of immunobiologics for the management of oral disease in Sjögren's syndrome (SS).

MATERIALS AND METHODS

MEDLINE^® , Embase, Scopus, and the Cochrane Library were searched for evidence on the use of immunobiologics for management of glandular disease in SS. Primary outcomes were xerostomia and salivary gland dysfunction, assessed via visual analogue scales, disease-specific scales for SS, measurement of salivary flow, ultrasound data, and quality of life measures.

RESULTS

Seventeen studies (11 randomized controlled trials and 6 observational studies) met inclusion criteria. Rituximab showed efficacy in improving salivary gland function but not xerostomia. Abatacept showed promise in improving both xerostomia and salivary flow. Belimumab exhibited long-term improvement of salivary flow and subjective measures. The novel agent CFZ533 improved both disease activity and patient-reported indexes.

CONCLUSIONS

There is strong evidence pointing to the efficacy of rituximab in the management of oral disease in SS. Future controlled trials may elucidate the efficacy of belimumab and abatacept. The new drug CFZ533 is a promising alternative for the management of SS and its salivary gland involvement. In considering these agents, the promise of efficacy must be balanced against the harmful effects associated with biologic agents.

Impact of the 2014 NIH chronic graft-versus-host disease scoring criteria modifications assessed in a large cohort of severely affected patients

In 2005, the National Institutes of Health (NIH) chronic graft-versus-host disease (cGVHD) consensus project provided diagnosis and staging criteria, based mostly on clinical experience and expert opinion. These criteria were revised in 2014, aiming to provide enhanced specificity and clarity. However, the impact of 2014 changes to the original NIH cGVHD severity scoring criteria has not been reported. In this study, 284 patients, prospectively enrolled on the National Cancer Institute's cross-sectional cGVHD natural history study, were scored using the 2005 NIH cGVHD criteria and then rescored according to the 2014 modifications. In comparing the two criteria, 2014 cGVHD global severity scoring resulted in a tendency toward being categorized as milder scores (75 vs. 72% of severe score per 2014, p = 0.0009), with a statistically significant shift in NIH liver and lung scores toward milder categories (p < 0.0001). 2005 and 2014 NIH global severity scores showed a significant association with reduced grip strength (p < 0.0001), reduced joint range of motion (p = 0.0003), and the subspecialist evaluation score (p < 0.0001). Poor survival prediction of the severe NIH lung score is also retained in the new criteria (p = 0.0012). These findings support the use of 2014 cGVHD scoring criteria in continuous efforts to develop better classification systems.

Influenza A Virus Negative Strand RNA Is Translated for CD8+ T Cell Immunosurveillance

Probing the limits of CD8⁺ T cell immunosurveillance, we inserted the SIINFEKL peptide into influenza A virus (IAV)-negative strand gene segments. Although IAV genomic RNA is considered noncoding, there is a conserved, relatively long open reading frame present in segment 8, encoding a potential protein termed NEG8. The biosynthesis of NEG8 from IAV has yet to be demonstrated. Although we failed to detect NEG8 protein expression in IAV-infected mouse cells, cell surface K^b-SIINFEKL complexes are generated when SIINFEKL is genetically appended to the predicted C terminus of NEG8, as shown by activation of OT-I T cells in vitro and in vivo. Moreover, recombinant IAV encoding of SIINFEKL embedded in the negative strand of the neuraminidase-stalk coding sequence also activates OT-I T cells in mice. Together, our findings demonstrate both the translation of sequences on the negative strand of a single-stranded RNA virus and its relevance in antiviral immunosurveillance.

Human Th17 activity profile in oral chronic Graft-versus-Host Disease

Immunotherapy using allogeneic hematopoietic stem cell transplantation (alloHSCT) is highly effective; however, its use is limited by the incidence of chronic graft-versus-host disease (cGVHD). The oral cavity, which is affected by cGVHD, is a highly accessible mucosal site with its own local biofluid – saliva – but little is known about the pathogenic progression of cGVHD in oral tissues. This study examined the relationship between salivary gland gene expression, salivary proteins and the immune cell network within oral tissues at onset of oral cGVHD.

Patients enrolled in NIH cGVHD trials (NCT00331968, NCT00520130, NCT01851382) were evaluated after cGVHD onset. Whole saliva from individual oral cGVHD patients (n=58) and healthy controls (n=10) was analyzed for a 13-plex panel of immune-related analytes and revealed elevated expression of tissue remodeling factors and IFN- and IL-17-induced chemokines that correlated with clinical scoring of cGVHD severity in a multivariate analysis. Microarray of patient MSG indicated canonical pathway expression including innate immune pathways, and IFN, IL-17 and IL-22-induced processes. Confocal microscopy confirmed the presence of immune cells in oral tissues. Extending our laboratory’s prior observations of Th1 effectors in BM, Th17 cells (CD4+/CD161+/IL-17+) and Type I IFN-induced factors were identified in the majority of available BM and MSG of cGVHD patients, but not in unaffected post-transplant controls.

Current analyses in cGVHD patient samples implicate activation of IFN pathways and presence of Th17 cells in oral tissues in the pathogenesis of oral cGVHD, though the specific sequence and role of these cells in salivary gland pathogenesis during cGVHD remain to be determined.

Upregulation of IFN-Inducible and Damage-Response Pathways in Chronic Graft-versus-Host Disease

Although chronic graft-versus-host disease (CGVHD) is the primary nonrelapse complication of allogeneic transplantation, understanding of its pathogenesis is limited. To identify the main operant pathways across the spectrum of CGVHD, we analyzed gene expression in circulating monocytes, chosen as in situ systemic reporter cells. Microarrays identified two interrelated pathways: 1) IFN-inducible genes, and 2) innate receptors for cellular damage. Corroborating these with multiplex RNA quantitation, we found that multiple IFN-inducible genes (affecting lymphocyte trafficking, differentiation, and Ag presentation) were concurrently upregulated in CGVHD monocytes compared with normal subjects and non-CGVHD control patients. IFN-inducible chemokines were elevated in both lichenoid and sclerotic CGHVD plasma and were linked to CXCR3+ lymphocyte trafficking. Furthermore, the levels of the IFN-inducible genes CXCL10 and TNFSF13B (BAFF) were correlated at both the gene and the plasma levels, implicating IFN induction as a factor in elevated BAFF levels in CGVHD. In the second pathway, damage-/pathogen-associated molecular pattern receptor genes capable of inducing type I IFN were upregulated. Type I IFN-inducible MxA was expressed in proportion to CGVHD activity in skin, mucosa, and glands, and expression of TLR7 and DDX58 receptor genes correlated with upregulation of type I IFN-inducible genes in monocytes. Finally, in serial analyses after transplant, IFN-inducible and damage-response genes were upregulated in monocytes at CGVHD onset and declined upon therapy and resolution in both lichenoid and sclerotic CGVHD patients. This interlocking analysis of IFN-inducible genes, plasma analytes, and tissue immunohistochemistry strongly supports a unifying hypothesis of induction of IFN by innate response to cellular damage as a mechanism for initiation and persistence of CGVHD.

Characterization and Risk Factor Analysis of Osteoporosis in a Large Cohort of Patients with Chronic Graft-versus-Host Disease

The National Institutes of Health Chronic Graft-versus-Host Disease (cGVHD) Consensus Project Ancillary and Supportive Care Guidelines recommend annual assessment of bone mineral density (BMD) to monitor bone health. The study of osteoporosis in patients with cGVHD has been limited to small numbers of patients, and the guidelines are based on experience with other chronic diseases and expert opinion. We hypothesized that the prevalence of osteoporosis is high in a cohort of 258 patients with moderate to severe cGVHD because of prolonged exposure to risk factors for osteoporosis after allogeneic hematopoietic stem cell transplantation. We defined osteoporosis using BMD criteria (T-score ≤-2.5) at 3 anatomic sites-the femoral neck (FN), lumbar spine (LS), and total hip (TH)-and characterized risk factors through univariate and multivariate analyses. We found that low body weight (FN, P < .0001; LS, P = .0002; TH, P < .0001), malnutrition (FN, P = .0002; LS, P = .03; TH, P = .0076), higher platelet count (FN, P = .0065; TH, P = .0025), higher average National Institutes of Health organ score (FN, P = .038), higher prednisone dose (LS, P = .032), lower complement component 3 (LS, P = .0073), and physical inactivity (FN, P = .01) were associated with osteoporosis in at least 1 site. T-scores were significantly lower in the FN compared with the LS or TH (P < .0001 for both). The prevalence of osteoporosis and osteopenia was high (17% and 60%, respectively), supporting current recommendations for frequent monitoring of BMD. The association of higher platelet count in patients with cGVHD and osteoporosis has not been reported previously and represents a new area of interest in the study of osteoporosis after allogeneic hematopoietic stem cell transplantation.

Oral disease profiles in chronic graft versus host disease

At least half of patients with chronic graft-versus-host-disease (cGVHD), the leading cause of morbidity and non-relapse mortality after allogeneic stem cell transplantation, have oral manifestations: mucosal lesions, salivary dysfunction, and limited mouth-opening. cGVHD may manifest in a single organ or affect multiple organ systems, including the mouth, eyes, and the skin. The interrelationship of the 3 oral manifestations of cGVHD with each other and with the specific manifestations of extraoral cGVHD has not been studied. In this analysis, we explored, in a large group of patients with cGVHD, the potential associations between: (1) oral mucosal disease and erythematous skin disease, (2) salivary gland dysfunction and lacrimal gland dysfunction, and (3) limited mouth-opening and sclerotic skin cGVHD. Study participants, enrolled in a cGVHD Natural History Protocol (NCT00331968, n = 212), underwent an oral examination evaluating: (1) mucosal cGVHD [NIH Oral Mucosal Score (OMS)], (2) salivary dysfunction (saliva flow and xerostomia), and (3) maximum mouth-opening measurement. Parameters for dysfunction (OMS > 2, saliva flow ≤ 1 mL/5 min, mouth-opening ≤ 35 mm) were analyzed for association with skin cGVHD involvement (erythema and sclerosis, skin symptoms), lacrimal dysfunction (Schirmer's tear test, xerophthalmia), Lee cGVHD Symptom Scores, and NIH organ scores. Oral mucosal disease (31% prevalence) was associated with skin erythema (P < 0.001); salivary dysfunction (11% prevalence) was associated with lacrimal dysfunction (P = 0.010) and xerostomia with xerophthalmia (r = 0.32, P = 0.001); and limited mouth-opening (17% prevalence) was associated with skin sclerosis (P = 0.008) and skin symptoms (P = 0.001). There was no association found among these 3 oral cGVHD manifestations. This analysis supports the understanding of oral cGVHD as 3 distinct diseases: mucosal lesions, salivary gland dysfunction, and mouth sclerosis. Clear classification of oral cGVHD as 3 separate manifestations will improve clinical diagnosis, observational research data collection, and the definitions of outcome measures in clinical trials.

Clinical significance of autoantibodies in a large cohort of patients with chronic graft-versus-host disease defined by NIH criteria

There is an unmet need for identifying new clinical biomarkers in chronic Graft-versus-Host-disease (cGVHD) suitable for diagnosis and disease monitoring. Circulating autoantibodies represent an ongoing immune response and suggest a pathogenic role for B cells in cGVHD. Autoantibodies could be useful markers of cGVHD disease activity, severity, or organ specificity; however, their clinical utility is not established. The focus of this study was to determine the incidence and associations of a broad array of clinical autoantibodies with cGVHD manifestations in a large patient cohort characterized by NIH criteria. A panel of 21 circulating antibodies commonly used in clinical medicine was tested in 280 cGVHD patients (70% severe) enrolled in a cross-sectional prospective natural history study. Median cGVHD duration was two years. Patients with circulating autoantibodies (62%) had significantly higher levels of IgM (P < 0.0001), IgG (P < 0.0001), and IgA (P = 0.001), elevated uric acid (P = 0.008) and total protein (P = 0.0004), and higher numbers of CD3+ (P = 0.002), CD4+ (P = 0.001), CD8+ (P = 0.023) T cells, and CD19+ B cells (P < 0.0001). Multiple antibodies were detected in 35% of patients. Prior rituximab therapy (n = 66) was associated with reduced presence of autoantibodies (48 vs. 66% P = 0.01). Only oral cGVHD was significantly associated with presence of autoantibodies in this study (P = 0.028). No significant associations were found between cGVHD activity and severity, and presence of autoantibodies. Circulating autoantibodies are common in patients with advanced cGVHD. Their presence is associated with better quantitative immunologic reconstitution but does not have utility as a clinical biomarker of cGVHD.

Oral manifestations of systemic autoimmune and inflammatory diseases: diagnosis and clinical management

CONTEXT

Systemic autoimmune and inflammatory diseases often manifest oral lesions in their earliest stages, and early diagnosis, which may be spurred by a dental examination, is key for improved outcomes. After systemic diagnosis, oral lesions benefit from specialized care by dentists in collaboration with the medical team. This review aims to educate dental clinicians about the most relevant systemic autoimmune and inflammatory conditions with accompanying oral lesions, their implications for health, and management strategies supported by the biomedical literature and clinical experience. Ulcerative conditions including Behcet and Crohn diseases are discussed, along with rheumatic conditions including Sjögren syndrome, lupus erythematosus, and rheumatoid arthritis.

EVIDENCE ACQUISITION

Evidence was accumulated through PubMed searches using pertinent keywords for each subsection. References were reviewed and original publications examined to verify the accuracy of the information. We focused on evidence included in current reviews and randomized trials. Recommendations were supported by multiple studies and consensus expert opinion.

EVIDENCE SYNTHESIS

Disease phenotypes described and clinical recommendations were synthesized from best-quality evidence available for each disease. Efforts were made to describe evidence selection within each disease section.

CONCLUSIONS

Dentists play an important role in the early detection and multidisciplinary medical management of complex autoimmune diseases. It is important to recognize prevalent medical and dental issues and special needs of patients with autoimmune conditions. The management of many inflammatory conditions is similar, and often begins with the use of topical steroids, analgesics, and antimicrobial treatments, in addition to careful attention to oral hygiene and appropriate fluoride usage. In this brief review, we aim to discuss the presentation/prevalence, diagnosis, and treatment of oral manifestations encountered in autoimmune, autoinflammatory and systemic chronic inflammatory diseases. Systemic autoimmune conditions are estimated to affect 5% to 8% of Americans.(1) Oral manifestations are encountered with high frequency, and are often the first clinical signs or symptoms of the general disease. Optimal management of complex autoimmune diseases requires a multidisciplinary medical team including dentists to care for lesions of the oral cavity. The dental practitioner may be asked to play a primary role in the diagnosis of such conditions and to participate with other health professionals working together to achieve effective clinical management. To aid in this process, we discuss in this article the current general knowledge of systemic autoimmune conditions that present with prevalent oral manifestations. The focus is on the diagnosis and management of the oral component of each disease. Importantly, whereas the etiology and pathogenesis and systemic clinical presentation may vary, presentation in the oral cavity is often similar and many conditions involve oral ulcerations. For this reason, we discuss the differential diagnosis and management of the most common oral ulcerations in a general section and subsequently address individual conditions that present with oral ulcerations. Similarly, treatment of various autoimmune/inflammatory oral conditions is often common and involves modulation or suppression of the immune response locally and/or systemically and will be therefore addressed in a common section as well as individually for each disease when unique treatment regimens are recommended. We present here our general treatment recommendations based on clinical experience and literature review; however, it is critical that good clinical judgment and specifics of an individual case should determine the appropriate dental/oral medicine intervention for a specific patient.

National Institutes of Health chronic graft-versus-host disease staging in severely affected patients: organ and global scoring correlate with established indicators of disease severity and prognosis

Between 2004 and 2010, 189 adult patients were enrolled on the National Cancer Institute's cross-sectional chronic graft-versus-host disease (cGVHD) natural history study. Patients were evaluated by multiple disease scales and outcome measures, including the 2005 National Institutes of Health (NIH) Consensus Project cGVHD severity scores. The purpose of this study was to assess the validity of the NIH scoring variables as determinants of disease severity in severely affected patients in efforts to standardize clinician evaluation and staging of cGVHD. Out of 189 patients enrolled, 125 met the criteria for severe cGVHD on the NIH global score, 62 of whom had moderate disease, with a median of 4 (range, 1-8) involved organs. Clinician-assigned average NIH organ score and the corresponding organ scores assigned by subspecialists were highly correlated (r = 0.64). NIH global severity scores showed significant associations with nearly all functional and quality of life outcome measures, including the Lee Symptom Scale, Short Form-36 Physical Component Scale, 2-minute walk, grip strength, range of motion, and Human Activity Profile. Joint/fascia, skin, and lung involvement affected function and quality of life most significantly and showed the greatest correlation with outcome measures. The final Cox model with factors jointly predictive for survival included the time from cGVHD diagnosis (>49 versus ≤49 months, hazard ratio [HR] = 0.23; P = .0011), absolute eosinophil count at the time of NIH evaluation (0-0.5 versus >0.5 cells/μL, HR = 3.95; P = .0006), and NIH lung score (3 versus 0-2, HR = 11.02; P < .0001). These results demonstrate that NIH organs and global severity scores are reliable measures of cGVHD disease burden. The strong association with subspecialist evaluation suggests that NIH organ and global severity scores are appropriate for clinical and research assessments, and may serve as a surrogate for more complex subspecialist examinations. In this population of severely affected patients, NIH lung score is the strongest predictor of poor overall survival, both alone and after adjustment for other important factors.

Oral chronic graft-versus-host disease: current pathogenesis, therapy, and research

Optimal management of complex autoimmune diseases requires a multidisciplinary medical team including dentists to care for lesions of the oral cavity. In this review, we discuss the presentation, prevalence, diagnosis, and treatment of oral manifestations in chronic graft-versus-host disease (cGVHD), which is a major late complication in patients treated by allogeneic hematopoietic stem cell transplantation. We assess current general knowledge of systemic and oral cGVHD and present general treatment recommendations based on literature review and our clinical experience. Additionally, we review areas where the understanding of oral cGVHD could be improved by further research and address tools with which to accomplish the long-term goal of providing better health and quality of life to patients with cGVHD.

Quantitative salivary proteomic differences in oral chronic graft-versus-host disease

Purpose

Chronic graft-versus-host disease (cGVHD) is a severe immunological complication that occurs after allogeneic hematopoietic stem cell transplantation (HSCT). Although oral cGVHD occurs in >25 % of cGVHD patients and leads to decreased quality of life, its etiology is poorly understood. The present retrospective cross-sectional analysis of oral cGVHD patients sought to (1) test the feasibility of liquid chromatography tandem mass spectrometry (LC-MS/MS) to identify protein biomarkers of oral cGVHD and (2) to gain a clearer understanding of salivary proteins impacted by oral cGVHD.

Methods

Using unstimulated whole saliva, we compared pooled saliva from five patients with a diagnosis of moderate or severe oral cGVHD, with a gender-and age- matched pool of five cGVHD patients with no oral mucosal findings. LC-MS/MS was used to identify salivary proteins, followed by Ingenuity Pathway Analysis (IPA). Selected mass spectrometric findings, including lactotransferrin, lactoperoxidase, and albumin, were confirmed by targeted label-free quantification.

Results

LC-MS/MS led to confident identification of 180 proteins. Of these proteins, 102 changed in abundance at least 2 fold, including 12 proteins identified only in the No oral cGVHD group. Downregulation of ~0.4 fold was confirmed for both lactotransferrin and lactoperoxidase in Oral cGVHD saliva using targeted label-free quantification. IPA analysis implicated pathways involved in cellular metabolism and immunoregulation.

Conclusions

Reduction of salivary lactoperoxidase, lactotransferrin, and several cysteine proteinase inhibitor family proteins suggests impaired oral antimicrobial host immunity in cGVHD patients. This shotgun proteomic analysis of oral cGVHD saliva using targeted label-free quantification of select proteins supports the use of mass spectrometry for future validation in a large patient population as noninvasive tests for screening, early detection, and monitoring of cGVHD.

Electronic supplementary material

The online version of this article (doi:10.1007/s10875-012-9738-4) contains supplementary material, which is available to authorized users.

Stress and the anti-influenza immune response: repeated social defeat augments clonal expansion of CD8(+)T cells during primary influenza A viral infection

Social disruption stress (SDR) prior to primary influenza A virus (IAV) infection augments memory to IAV re-challenge in a T cell-specific manner. However, the effect of SDR on the primary anti-viral immune response has not been elucidated. In this study, SDR-infected (INF) mice terminated viral gene expression earlier and mounted an enhanced pulmonary IAV-specific CD8(+)T cell response versus controls. Additionally, SDR-INF mice had a more pro-inflammatory lung profile prior to and during infection and an attenuated corticosterone response. These data demonstrate neuroendocrine modification of the lung microenvironment and increased antigen-specific T cell activation, clonal expansion and viral control in stress-exposed mice.

Chemokines control naive CD8+ T cell selection of optimal lymph node antigen presenting cells

CCR5-binding chemokines produced in the draining lymph node after vaccinia virus infection guide naive CD8⁺ T cells toward DCs and away from the macrophage-rich zone, thereby facilitating optimal CD8⁺ T cell activation and cytokine production.

Naive antiviral CD8⁺ T cells are activated in the draining LN (DLN) by dendritic cells (DCs) presenting viral antigens. However, many viruses infect LN macrophages, which participate in initiation of innate immunity and B cell activation. To better understand how and why T cells select infected DCs rather than macrophages, we performed intravital microscopy and ex vivo analyses after infecting mice with vaccinia virus (VV), a large DNA virus that infects both LN macrophages and DCs. Although CD8⁺ T cells interact with both infected macrophages and DCs in the LN peripheral interfollicular region (PIR), DCs generate more frequent and stable interactions with T cells. VV infection induces rapid release of CCR5-binding chemokines in the LN, and administration of chemokine-neutralizing antibodies diminishes T cell activation by increasing T cell localization to macrophages in the macrophage-rich region (MRR) at the expense of PIR DCs. Similarly, DC ablation increases both T cell localization to the MRR and the duration of T cell–macrophage contacts, resulting in suboptimal T cell activation. Thus, virus-induced chemokines in DLNs enable antiviral CD8⁺ T cells to distinguish DCs from macrophages to optimize T cell priming.

Sex differences in the response to influenza virus infection: modulation by stress

Influenza virus infection is a significant public health problem; however factors affecting the incidence and severity of disease have not been fully elucidated. The present study sought to examine the role of sex and stress in mediating susceptibility to an influenza viral infection in mice. Male and female mice underwent repeated cycles of restraint (RST) stress, followed by an influenza A/PR8 virus infection. Following these manipulations, levels of circulating corticosterone, lung proinflammatory cytokine gene expression and sickness behavior were examined. The data indicate sex differences in several aspects of the response to the A/PR8 virus infection. The kinetics of lung interleukin-1β mRNA expression were faster in infected males compared to females, while circulating corticosterone levels were elevated in infected females, but not in males. Anorexia and reduced saccharin consumption began earlier and symptoms were more pronounced in infected males than in females. In addition, RST modulated the response to the A/PR8 virus infection. Proinflammatory cytokine gene expression in response to infection was enhanced and sickness behavior was modulated by RST in both males and females. These data suggest that males mount more vigorous immune and behavioral responses to influenza viral infection compared to females, and stress exacerbates the response in both males and females. In conclusion, complex interactions between biological and behavioral factors are involved in mediating individual differences in health and disease. Additional studies may help uncover some of the factors contributing to the individual differences in susceptibility to influenza infection.

Immunogenic dendritic cells primed by social defeat enhance adaptive immunity to influenza A virus

Dendritic cells (DCs) sample their surrounding microenvironment and consequently send immunogenic or regulatory signals to T cells during DC/T cell interactions, shaping the primary adaptive immune response to infection. The microenvironment resulting from repeated social defeat increases DC co-stimulatory molecule expression and primes DCs for enhanced cytokine responses in vitro. In this study, we show that social disruption stress (SDR) results in the generation of immunogenic DCs, capable of conferring enhanced adaptive immunity to influenza A/PR/8/34 infection. Mice infected with influenza A/PR/8/34 virus 24 h after the adoptive transfer of DCs from SDR mice had significantly increased numbers of D(b)NP(366-74)CD8(+) T cells, increased IFN-γ and IFN-α mRNA, and decreased influenza M1 mRNA expression in the lung during the peak primary response (9 days post-infection), compared to mice that received DCs from naïve mice. These data demonstrate that repeated social defeat is a significant environmental influence on immunogenic DC activation and function.

Influenza virus-specific immunological memory is enhanced by repeated social defeat

Immunological memory (MEM) development is affected by stress-induced neuroendocrine mediators. Current knowledge about how a behavioral interaction, such as social defeat, alters the development of adaptive immunity, and MEM is incomplete. In this study, the experience of social disruption stress (SDR) prior to a primary influenza viral infection enhanced the frequency and function of the T cell memory pool. Socially stressed mice had a significantly enlarged population of CD8(+) T cells specific for the immunodominant NP366-74 epitope of A/PR/8/34 virus in lung and spleen tissues at 6-12 wk after primary infection (resting memory). Moreover, during resting memory, SDR-MEM mice responded with an enhanced footpad delayed-type hypersensitivity response, and more IFN-gamma-producing CD4(+) T cells were detected after ex vivo stimulation. When mice were rechallenged with A/PR/8/34 virus, SDR-MEM mice terminated viral gene expression significantly earlier than MEM mice and generated a greater D(b)NP(366-74)CD8(+) T cell response in the lung parenchyma and airways. This enhancement was specific to the T cell response. SDR-MEM mice had significantly attenuated anti-influenza IgG titers during resting memory. Similar experiments in which mice were primed with X-31 influenza and challenged with A/PR/8/34 virus elicited similar enhancements in the splenic and lung airway D(b)NP(366-74)CD8(+) T cell populations in SDR-MEM mice. This study demonstrates that the experience of repeated social defeat prior to a primary viral infection significantly enhances virus-specific memory via augmentation of memory T cell populations and suggests that social stressors should be carefully considered in the design and analysis of future studies on antiviral immunity.

Repeated social defeat activates dendritic cells and enhances Toll-like receptor dependent cytokine secretion

Stress hormones significantly impact dendritic cell (DC) activation and function, typically in a suppressive fashion. However, a social stressor termed social disruption (SDR) has been shown to induce an increase in inflammatory responses and a state of glucocorticoid resistance in splenic CD11b+ monocytes. These experiments were designed to determine the effects of SDR on DC activation, Toll-like receptor-induced cytokine secretion, and glucocorticoid sensitivity. Compared to cells obtained from control animals, splenic DCs from SDR mice displayed increased levels of MHC I, CD80, and CD44, indicative of an activated phenotype. In addition, DCs from SDR mice produced comparatively higher TNF-alpha, IL-6, and IL-10 in response to in vitro stimulation with LPS and CpG DNA. Increased amounts of TNF-alpha and IL-6 were also evident in SDR DC cultures stimulated with poly(I:C). Furthermore, as shown previously in CD11b+ monocytes, the CD11c+ DCs obtained from SDR mice were glucocorticoid resistant. Taken together, the data suggest that social stress, in the absence of any immune challenge, activates DCs, increases DC cytokine secretion in response to Toll-specific stimuli and renders DCs glucocorticoid resistant.

Oil-in-water microemulsions stabilized by charged diblock copolymers

We present here oil-in-water microemulsions stabilized by charged diblock copolymers alone, along with their structural characterization by small-angle neutron scattering measurements. They consist of swollen spherical micelles containing small amounts of oil in their core, which is surrounded by a corona of stretched polyelectrolyte chains. Structural changes, including core size variations, are evidenced when using a cosurfactant, or upon addition of salt, through a contraction of the charged corona. Attempts to relate the micellar structure to the individual copolymer characteristics are also presented, and show that the size of the hydrophobic block mainly determines that of the micelles.

Spherical polyelectrolyte block copolymer micelles: structural change in presence of monovalent salt

Spherical polyelectrolyte block copolymer micelles were investigated as a function of added NaCl salt concentration using Small-Angle Neutron Scattering (SANS) and Light Scattering (LS). The micelles are formed by the self-association of charged-neutral copolymers made of a long deuterated polyelectrolyte moiety (NaPSS(d))251 and a short hydrophobic moiety (PEP)52. In presence of salt, the core shape and the aggregation number of the micelles are not affected. The hydrodynamic radius of the micelle is found to be identical to the radius of the whole micelle deduced from neutron scattering and thus the hydrodynamic radius is a valid measure of the corona thickness. At the lowest salt concentrations investigated the thickness of the corona, R(s), remains essentially constant and a contraction is observed above an added-salt concentration c(s) of 2 x 10(-2) M where this crossover concentration corresponds to the average ionic strength of the free counterions in the corona. The contraction takes place while maintaining a rod-like behavior of the chains at short scale and obeys to: R(s) approximately c(s)(-0.18). The exponent 0.18 suggests an electrostatic persistence length proportional to the Debye screening length.

Thickness and density profiles of polyelectrolyte brushes: dependence on grafting density and salt concentration

We have performed neutron reflectivity measurements on a monolayer of charged diblock copolymers in a Langmuir trough, and determined precise density profiles of the polyelectrolyte brush at different densities. We obtain profiles in good agreement with existing self-consistent field computations, both for the osmotic and the salted brush regime. We show that the osmotic brush's thickness increases with density.

Capillary electrophoresis of associative diblock copolymers

Water soluble diblock copolymers composed of a long poly(styrene sulfonate) chain (between 200 and 400 monomers) and a short poly(ethylene propylene) or poly(tert.-butylstyrene) hydrophobic end (20-50 monomers) are highly associative and form micelles in aqueous solution. The micelles are composed of a small hydrophobic core and a polyelectrolyte corona, the dimensions of which can be estimated by neutron and light scattering. These physical techniques are, however, not amenable to discriminate easily between the free copolymer and the copolymer micelle. Capillary electrophoresis was implemented in this work as a new and effective tool to investigate the behaviour of such associative copolymer systems. Since the rate of exchange between the micellised and free states is very slow in comparison with the time scale of the electrophoretic process, the electropherograms of the diblock copolymers obtained in plain aqueous borate buffers exhibit two peaks assigned to the two states mentioned above. The identification of the two peaks was first made on the basis of the retention orders of the two peaks equally obtained in similar conditions by size-exclusion chromatography. The copolymer micelles appeared to have a smaller electrophoretic mobility than the free copolymers. This peak assignment is also consistent with the observed ratio of the time-corrected peak areas and peak dispersions. The effects of the copolymer concentration, electric field, temperature and hydroorganic composition of the medium was also studied. Such systems do not exhibit a defined concentration threshold equivalent to a classical critical micelle concentration. Adding methanol to the electrolyte resulted in the progressive loss of baseline return between the two peaks, which might be attributed to a slight increase in the rate of exchange between the two states. Finally, adding a neutral surfactant to the electrolyte at a concentration in excess of its critical micelle concentration resulted in a decrease in the electrophoretic mobility of the peak attributed to the free copoplymer, while the electrophoretic mobility of the copolymer micelle remained unperturbed.

Improved orthopaedic bone cement formulations based on rubber toughening

Poly(methylmethacrylate) (PMMA) bone cements have been used for the fixation of hip and knee implants since the early 1960s. Aseptic loosening, related to fracture of the PMMA, continues to be the primary mode of failure for these prostheses. Failed prostheses must be replaced causing additional expense and patient trauma. Furthermore, the average lifetime of the revised prosthesis is significantly lower than that of a primary prosthesis. Recent work by Moseley and co-workers led to the development of a promising new rubber toughened cement. It is comprised of a matrix of the traditional PMMA with dispersed rubber particles to modify mechanical properties and, in particular, improve fracture toughness. The fracture toughness of the experimental material was 167% greater than the toughness of a nontoughened control; however, the elastic modulus and compressive strength were reduced. The reductions in properties should not pose a clinical problem based on results of the implant model reported by Moseley. More serious concerns were mixing and delivery problems and high residual monomer concentrations. The formulation and chemical/mechanical characterization of new toughened acrylic formulations that have residual monomer levels equivalent to Simplex and better mixing properties are reported.