Langerhans cells protect from allergic contact dermatitis in mice by tolerizing CD8+ T cells and activating Foxp3+ regulatory T cells

Allergic contact dermatitis is the most frequent occupational disease in industrialized countries. It is caused by CD8(+) T cell-mediated contact hypersensitivity (CHS) reactions triggered at the site of contact by a variety of chemicals, also known as weak haptens, present in fragrances, dyes, metals, preservatives, and drugs. Despite the myriad of potentially allergenic substances that can penetrate the skin, sensitization is relatively rare and immune tolerance to the substance is often induced by as yet poorly understood mechanisms. Here we show, using the innocuous chemical 2,4-dinitrothiocyanobenzene (DNTB), that cutaneous immune tolerance in mice critically depends on epidermal Langerhans cells (LCs), which capture DNTB and migrate to lymph nodes for direct presentation to CD8(+) T cells. Depletion and adoptive transfer experiments revealed that LCs conferred protection from development of CHS by a mechanism involving both anergy and deletion of allergen-specific CD8(+) T cells and activation of a population of T cells identified as ICOS(+)CD4(+)Foxp3(+) Tregs. Our findings highlight the critical role of LCs in tolerance induction in mice to the prototype innocuous hapten DNTB and suggest that strategies targeting LCs might be valuable for prevention of cutaneous allergy.

Skin langerin+ dendritic cells transport intradermally injected anti-DEC-205 antibodies but are not essential for subsequent cytotoxic CD8+ T cell responses

Incorporation of Ags by dendritic cells (DCs) increases when Ags are targeted to endocytic receptors by mAbs. We have previously demonstrated in the mouse that mAbs against C-type lectins administered intradermally are taken up by epidermal Langerhans cells (LCs), dermal Langerin(neg) DCs, and dermal Langerin(+) DCs in situ. However, the relative contribution of these skin DC subsets to the induction of immune responses after Ag targeting has not been addressed in vivo. We show in this study that murine epidermal LCs and dermal DCs transport intradermally injected mAbs against the lectin receptor DEC-205/CD205 in vivo. Skin DCs targeted in situ with mAbs migrated through lymphatic vessels in steady state and inflammation. In the skin-draining lymph nodes, targeting mAbs were found in resident CD8a(+) DCs and in migrating skin DCs. More than 70% of targeted DCs expressed Langerin, including dermal Langerin(+) DCs and LCs. Numbers of targeted skin DCs in the nodes increased 2-3-fold when skin was topically inflamed by the TLR7 agonist imiquimod. Complete removal of the site where OVA-coupled anti-DEC-205 had been injected decreased endogenous cytotoxic responses against OVA peptide-loaded target cells by 40-50%. Surprisingly, selective ablation of all Langerin(+) skin DCs in Langerin-DTR knock-in mice did not affect such responses independently of the adjuvant chosen. Thus, in cutaneous immunization strategies where Ag is targeted to DCs, Langerin(+) skin DCs play a major role in transport of anti-DEC-205 mAb, although Langerin(neg) dermal DCs and CD8a(+) DCs are sufficient to subsequent CD8(+) T cell responses.

Measles immune suppression:lessons from the Macaque Model

Measles remains a significant childhood disease, and is associated with a transient immune suppression. Paradoxically, measles virus (MV) infection also induces robust MV-specific immune responses. Current hypotheses for the mechanism underlying measles immune suppression focus on functional impairment of lymphocytes or antigen-presenting cells, caused by infection with or exposure to MV. We have generated stable recombinant MVs that express enhanced green fluorescent protein, and remain virulent in non-human primates. By performing a comprehensive study of virological, immunological, hematological and histopathological observations made in animals euthanized at different time points after MV infection, we developed a model explaining measles immune suppression which fits with the "measles paradox". Here we show that MV preferentially infects CD45RA - memory T-lymphocytes and follicular B-lymphocytes, resulting in high infection levels in these populations. After the peak of viremia MV-infected lymphocytes were cleared within days, followed by immune activation and lymph node enlargement. During this period tuberculin-specific T-lymphocyte responses disappeared, whilst strong MV-specific T-lymphocyte responses emerged. Histopathological analysis of lymphoid tissues showed lymphocyte depletion in the B- and T-cell areas in the absence of apoptotic cells, paralleled by infiltration of T-lymphocytes into B-cell follicles and reappearance of proliferating cells. Our findings indicate an immune-mediated clearance of MV-infected CD45RA - memory T-lymphocytes and follicular B-lymphocytes, which causes temporary immunological amnesia. The rapid oligoclonal expansion of MV-specific lymphocytes and bystander cells masks this depletion, explaining the short duration of measles lymphopenia yet long duration of immune suppression. © 2012 de Vries et al.

Skin Dendritic Cell Targeting via Microneedle Arrays Laden with Antigen-Encapsulated Poly-D, L-lactide-co-Glycolide Nanoparticles Induces Efficient Antitumor and Antiviral Immune Responses

The efficacious delivery of antigens to antigen-presenting cells (APCs), in particular, to dendritic cells (DCs), and their subsequent activation remains a significant challenge in the development of effective vaccines. This study highlights the potential of dissolving microneedle (MN) arrays laden with nanoencapsulated antigen to increase vaccine immunogenicity by targeting antigen specifically to contiguous DC networks within the skin. Following in situ uptake, skin-resident DCs were able to deliver antigen-encapsulated poly-d,l-lactide-co-glycolide (PGLA) nanoparticles to cutaneous draining lymph nodes where they subsequently induced significant expansion of antigen-specific T cells. Moreover, we show that antigen-encapsulated nanoparticle vaccination via microneedles generated robust antigen-specific cellular immune responses in mice. This approach provided complete protection in vivo against both the development of antigen-expressing B16 melanoma tumors and a murine model of para-influenza, through the activation of antigen-specific cytotoxic CD8(+) T cells that resulted in efficient clearance of tumors and virus, respectively. In addition, we show promising findings that nanoencapsulation facilitates antigen retention into skin layers and provides antigen stability in microneedles. Therefore, the use of biodegradable polymeric nanoparticles for selective targeting of antigen to skin DC subsets through dissolvable MNs provides a promising technology for improved vaccination efficacy, compliance, and coverage.

The lipopolysaccharide outer core of Yersinia enterocolitica serotype O:3 is required for virulence and plays a role in outer membrane integrity

Lipopolysaccharide (LPS) of Yersinia enterocolitica O:3 has an inner core linked to both the O-antigen and to an outer core hexasaccharide that forms a branch. The biological role of the outer core was studied using polar and non-polar mutants of the outer core biosynthetic operon. Analysis of O-antigen- and outer core-deficient strains suggested a critical role for the outer core in outer membrane properties relevant in resistance to antimicrobial peptides and permeability to hydrophobic agents, and indirectly relevant in resistance to killing by normal serum. Wild-type bacteria but not outer core mutants killed intragastrically infected mice, and the intravenous lethal dose was approximately 10(4)-fold higher for outer core mutants. After intragastric infection, outer core mutants colonized Peyer's patches and invaded mesenteric lymph nodes, spleen and liver, and induced protective immunity against wild-type bacteria. In mice co-infected intragastrically with an outer core mutant-wild type mixture, both strains colonized Peyer's patches similarly during the first 2 days, but the mutant was much less efficient in colonizing deeper organs and was cleared faster from Peyer's patches. The results demonstrate that outer core is required for Y. enterocolitica O:3 full virulence, and strongly suggest that it provides resistance against defence mechanisms (most probably those involving bactericidal peptides).

Corneal Allograft Rejection:Risk Factors, Diagnosis, Prevention, and Treatment

Recent advances in corneal graft technology, including donor tissue retrieval, storage and surgical techniques, have greatly improved the clinical outcome of corneal grafts. Despite these advances, immune mediated corneal graft rejection remains the single most important cause of corneal graft failure. Several host factors have been identified as conferring a "high risk" status to the host. These include: more than two quadrant vascularisation, with associated lymphatics, which augment the afferent and efferent arc of the immune response; herpes simplex keratitis; uveitis; silicone oil keratopathy; previous failed (rejected) grafts; "hot eyes"; young recipient age; and multiple surgical procedures at the time of grafting. Large grafts, by virtue of being closer to the host limbus, with its complement of vessels and antigen-presenting Langerhans cells, also are more susceptible to rejection. The diagnosis of graft rejection is entirely clinical and in its early stages the clinical signs could be subtle. Graft rejection is largely mediated by the major histocompatibility antigens, minor antigens and perhaps blood group ABO antigens and some cornea-specific antigens. Just as rejection is mediated by active immune mediated events, the lack of rejection (tolerance) is also sustained by active immune regulatory mechanisms. The anterior chamber associated immune deviation (ACAID) and probably, conjunctiva associated lymphoid tissue (CALT) induced mucosal tolerance, besides others, play an important role. Although graft rejection can lead to graft failure, most rejections can be readily controlled if appropriate management is commenced at the proper time. Topical steroids are the mainstay of graft rejection management. In the high-risk situations however, systemic steroids, and other immunosuppressive drugs such as cyclosporin and tacrolimus (FK506) are of proven benefit, both for treatment and prevention of rejection.

Evidence for chronic morbillivirus infection in the Mediterranean striped dolphin (Stenella coeruleoalba)

In the summer of 1990 an epizootic infection caused by a morbillivirus (DMV) killed several thousand striped dolphins (Stenella coeruleoalba) in the Mediterranean Sea. In 1991 and 1992 the epizootic reached Italian and Greek waters. The infection by DMV in the acute period of the epizootic caused encephalitis, pneumonia and depletion of lymph nodes. After 1990, the systemic infection apparently disappeared from the Catalonian coast, giving way to cases of chronic infection of the CNS. Dolphins that died between 1991 and May 1994 were necropsied, and investigated for lesions due to DMV, and for the presence of morbillivirus antigen in tissues. Encephalitis occurred in 6 dolphins in which DMV antigen was demonstrated in the CNS and which were without lesions or antigen in other, non-nervous tissues. Inflammatory lesions, gliosis, and DMV antigen decreased in density and amount from cerebral grey matter, through the thalamic areas to the medulla oblongata. The cerebellum was usually spared. Lesions consisted of non-suppurative encephalitis, with diffuse gliosis and glial nodules and neuronophagia, and loss of neurons. Perivascular cuffing of lymphocytes and plasma cells was present in the cerebral cortex and the white matter beneath the cortex. Multinucleate syncytia were not detected in any of the dolphins. The haemagglutinin of DMV was detected mainly in neurons in the cerebral cortical areas. There was no clear relationship between the presence and amount of DMV antigen and the density or chronicity of lesions. Viral inclusions were seen in haematoxylin and eosin stained sections in 3/6 dolphins, principally in the nucleus and the cytoplasm of neurons. In the immunoperoxidase stained sections, dense granular deposits of chromogen, similar to viral inclusions, were evident in all 6 dolphins. The change in the distribution of lesions and of DMV antigen, from systemic to localized in the CNS, and the clustering of systemic DMV infections in the first four months of the epizootic, giving rise to sporadic occurrence of local CNS infection in the subsequent four years, as well as the chronic nature of the CNS lesions, which closely resembles subacute sclerosing panencephalitis, strongly support the existence of a chronic morbillivirus infection in the striped dolphin, as a delayed consequence of the 1990 epizootic.

Secreted Proteins from the Helminth Fasciola hepatica Inhibit the Initiation of Autoreactive T Cell Responses and Prevent Diabetes in the NOD Mouse

Infections with helminth parasites prevent/attenuate auto-inflammatory disease. Here we show that molecules secreted by a helminth parasite could prevent Type 1 Diabetes (T1D) in nonobese diabetic (NOD) mice. When delivered at 4 weeks of age (coincident with the initiation of autoimmunity), the excretory/secretory products of Fasciola hepatica (FhES) prevented the onset of T1D, with 84% of mice remaining normoglycaemic and insulitis-free at 30 weeks of age. Disease protection was associated with suppression of IFN-γ secretion from autoreactive T cells and a switch to the production of a regulatory isotype (from IgG2a to IgG1) of autoantibody. Following FhES injection, peritoneal macrophages converted to a regulatory M2 phenotype, characterised by increased expression levels of Ym1, Arg-1, TGFβ and PD-L1. Expression of these M2 genetic markers increased in the pancreatic lymph nodes and the pancreas of FhES-treated mice. In vitro, FhES-stimulated M2 macrophages induced the differentiation of Tregs from splenocytes isolated from naïve NOD mice. Collectively, our data shows that FhES contains immune-modulatory molecules that mediate protection from autoimmune diabetes via the induction and maintenance of a regulatory immune environment.

The mediastinal staging accuracy of 18F-Fluorodeoxyglycose Positron Emission Tomography/Computed Tomography in non-small cell lung cancer with variable time intervals to surgery.

BACKGROUND: PET/CT scanning can determine suitability for curative therapy and inform decision making when considering radical therapy in patients with non-small cell lung cancer (NSCLC). Metastases to central mediastinal lymph nodes (N2) may alter such management decisions. We report a 2 year retrospective series assessing N2 lymph node staging accuracy with PET/CT compared to pathological analysis at surgery.

METHODS: Patients with NSCLC attending our centre (excluding those who had induction chemotherapy) who had staging PET/CT scans and pathological nodal sampling between June 2006 and June 2008 were analysed. For each lymph node assessed pathologically, the corresponding PET/CT status was determined. 64 patients with 200 N2 lymph nodes were analysed.

RESULTS: Sensitivity of PET/CT scans for indentifying involved N2 lymph nodes was
39%, specificity 96% and overall accuracy 90%. For individual lymph node analysis, logistic regression demonstrated a significant linear association between PET/CT sensitivity and time from scanning to surgery (p=0.031) but not for specificity and accuracy. Those scanned <9 weeks before pathological sampling were significantly more sensitive (64% >9 weeks, 0% ≥ 9 weeks, p=0.013) and more accurate (94% <9 weeks, 81% ≥ 9 weeks, p=0.007). Differences in specificity were not seen (97% <9 weeks, 91% ≥ 9 weeks, p=0.228). No significant difference in specificity was found at any time point.

CONCLUSIONS: We recommend that if a PET/CT scan is older than 9 weeks, and management would be altered by the presence of N2 nodes, re-staging of the
mediastinum should be undertaken.

Breast cancer following augmentation mammoplasty - a review of its impact on prognosis and management

The incidence of breast cancer in women with implants is increasing and will continue to do so for the foreseeable future due to the marked increase in breast implant insertion in recent years. Undoubtedly many of these women will wish to know whether the presence of implants worsens the prognosis of their breast cancer. Furthermore, the clinical management of such patients may be difficult, as aesthetic results are likely to be a major concern for women who have already undergone cosmetic surgery to the breast. There is no consensus on surgical approach to this scenario. This article reviews the literature on the prognosis of breast cancer patients with a history of augmentation mammoplasty and examines the available data regarding their surgical treatment. (c) 2007 Published by Elsevier Ltd on behalf of British Association of Plastic, Reconstructive and Aesthetic Surgeons.

Local recurrence in patients with large and locally advanced breast cancer treated with primary chemotherapy

Background: Primary chemotherapy is being given in the treatment of large and locally advanced breast cancers, but a major concern is local relapse after therapy. This paper has examined patients treated with primary chemotherapy and surgery (either breast-conserving surgery or mastectomy) and has examined the role of factors which may indicate those patients who are subsequently more likely to experience local recurrence of,disease.

Methods: A consecutive series of 173 women, with data available for 166 of these, presenting with large and locally advanced breast cancer (T2 >4 cm, T3, T4, or N2) were treated with primary chemotherapy comprising cyclophosphamide, vincristine, doxorubicin, and prednisolone and then surgery (either conservation or mastectomy with axillary surgery) followed by radiotherapy were examined.

Results: The clinical response rate of these patients was 75% (21% complete and 54% partial), with a complete pathological response rate of 15%. A total of 10 patients (6%) experienced local disease relapse, and the median time to relapse was 14 months (ranging from 3 to 40). The median survival in this group was 27 months (ranging from 13 to 78). In patients having breast conservation surgery, local recurrence occurred in 2%, and in those undergoing mastectomy 7% experience local relapse of disease. Factors predicting patients most likely to experience local recurrence were poor clinical response and residual axillary nodal disease after chemotherapy.

Conclusions: Excellent local control of disease can be achieved in patients with large and locally advanced breast cancers using a combination of primary chemotherapy, surgery and radiotherapy. However, the presence of residual tumor in the axillary lymph nodes after chemotherapy is a predictor of local recurrence and patients with a better clinical response were also less likely to experience local disease recurrence. The size and degree of pathological response did not predict patients most likely to experience recurrence of disease. (C) 2003 Excerpta Medica, Inc. All rights reserved.

Lymphatic mapping and sentinel node biopsy in breast cancer

Background Sentinel lymph node biopsy is a recently developed, minimally invasive technique for staging the axilla in patients with breast cancer. It has been suggested that this technique will avoid the morbidity associated with more extensive axillary dissection. A wide range of different methods and materials has been employed for lymphatic mapping, but there has been little consensus on the most reliable and reproducible technique.

Methods This is a comprehensive review of all published literature on sentinel node biopsy in breast cancer, using the Medline and Embase databases and cross-referencing of major articles on the subject.

Results and conclusion Sentinel node biopsy is a valid technique in breast cancer management, providing valuable axillary staging information. The optimal technique of lymphatic mapping utilizes a combination of vital blue dye and radiolabelled colloid. However, there remain controversial issues which require to be resolved before sentinel node biopsy becomes a widely accepted part of breast cancer care.

Lamina propria: The functional center of the bladder?

The bladder mucosa consists of the urothelium, basement membrane, and lamina propria (LP). Although the urothelium has been given much attention, it may be regarded as one part of a signaling system involving another equally important component of the bladder mucosa, namely, the LP. The LP lies between the basement membrane of the mucosa and the detrusor muscle and is composed of an extracellular matrix containing several types of cells, including fibroblasts, adipocytes, interstitial cells, and afferent and efferent nerve endings. In addition, the LP contains a rich vascular network, lymphatic vessels, elastic fibers, and smooth muscle fascicles (muscularis mucosae). The roles of the LP and its components in bladder function have not been definitively established, though it has been suggested to be the capacitance layer of the bladder, determining bladder compliance and enabling adaptive changes to increasing volumes. However, the bladder LP may also serve as a communication center, with an important integrative role in signal transduction to the central nervous system (nociception, mechanosensation). The LP may also, by means of its different components, make it possible for the urothelium to transmit information to other components of the bladder wall, contributing to activation of the detrusor muscle. In addition, the LP may serve as a source for production of factors influencing the growth of both the overlying urothelium and the underlying detrusor muscle.

IL-33 attenuates the development of experimental autoimmune uveitis

Interleukin (IL)-33 is associated with several important immune-mediated disorders. However, its role in uveitis, an important eye inflammatory disease, is unknown. Here we investigated the function of IL-33 in the development of experimental autoimmune uveitis (EAU). IL-33 and IL-33 receptor (ST2) were expressed in murine retinal pigment epithelial (RPE) cells in culture, and IL-33 increased the expression of Il33 and Mcp1 mRNA in RPE cells. In situ, IL-33 was highly expressed in the inner nuclear cells of the retina of naïve mice, and its expression was elevated in EAU mice. ST2-deficient mice developed exacerbated EAU compared with WT mice, and administration of IL-33 to WT mice significantly reduced EAU severity. The attenuated EAU in IL-33-treated mice was accompanied by decreased frequency of IFN-γ(+) and IL-17(+) CD4(+) T cells and reduced IFN-γ and IL-17 production but with increased frequency of IL-5(+) and IL-4(+) CD4 T cells and IL-5 production in the draining lymph node and spleen. Macrophages from the IL-33-treated mice show a significantly higher polarization towards an alternatively-activated macrophage (M2) phenotype. Our results therefore demonstrate that the endogenous IL-33/ST2 pathway plays an important role in EAU, and suggest that IL-33 represents a potential option for treatment of uveitis.

A methodological review of the Short Form Health Survey 36 (SF-36) and its derivatives among breast cancer survivors

Purpose: A systematic review of the validity, reliability and sensitivity of the Short Form (SF) health survey measures among breast cancer survivors.
Methods: We searched a number of databases for peer-reviewed papers. The methodological quality of the papers was assessed using the COnsenus-based Standards for the selection of health Measurement INstruments (COSMIN).
Results: The review identified seven papers that assessed the psychometric properties of the SF-36 (n = 5), partial SF-36 (n = 1) and SF-12 (n = 1) among breast cancer survivors. Internal consistency scores for the SF measures ranged from acceptable to good across a range of language and ethnic sub-groups. The SF-36 demonstrated good convergent validity with respective subscales of the Functional Assessment of Cancer Treatment—General scale and two lymphedema-specific measures. Divergent validity between the SF-36 and Lymph-ICF was modest. The SF-36 demonstrated good factor structure in the total breast cancer survivor study samples. However, the factor structure appeared to differ between specific language and ethnic sub-groups. The SF-36 discriminated between survivors who reported or did not report symptoms on the Breast Cancer Prevention Trial Symptom Checklist and SF-36 physical sub-scales, but not mental sub-scales, discriminated between survivors with or without lymphedema. Methodological quality scores varied between and within papers.
Conclusion: Short Form measures appear to provide a reliable and valid indication of general health status among breast cancer survivors though the limited data suggests that particular caution is required when interpreting scores provided by non-English language groups. Further research is required to test the sensitivity or responsiveness of the measure.