Skin T cell proliferative response to M protein and other cell wall and membrane proteins of group A streptococci in chronic plaque psoriasis

Group A Streptococcus induces CD1a-autoreactive T cells and promotes psoriatic inflammation

Group A Streptococcus (GAS) infection is associated with multiple clinical sequelae, including different subtypes of psoriasis. Such post-streptococcal disorders have been long known but are largely unexplained. CD1a is expressed at constitutively high levels by Langerhans cells and presents lipid antigens to T cells, but the potential relevance to GAS infection has not been studied. Here, we investigated whether GAS-responsive CD1a-restricted T cells contribute to the pathogenesis of psoriasis. Healthy individuals had high frequencies of circulating and cutaneous GAS-responsive CD4+ and CD8+ T cells with rapid effector functions, including the production of interleukin-22 (IL-22). Human skin and blood single-cell CITE-seq analyses of IL-22-producing T cells showed a type 17 signature with proliferative potential, whereas IFN-γ-producing T cells displayed cytotoxic T lymphocyte characteristics. Furthermore, individuals with psoriasis had significantly higher frequencies of circulating GAS-reactive T cells, enriched for markers of activation, cytolytic potential, and tissue association. In addition to responding to GAS, subsets of expanded GAS-reactive T cell clones/lines were found to be autoreactive, which included the recognition of the self-lipid antigen lysophosphatidylcholine. CD8+ T cell clones/lines produced cytolytic mediators and lysed infected CD1a-expressing cells. Furthermore, we established cutaneous models of GAS infection in a humanized CD1a transgenic mouse model and identified enhanced and prolonged local and systemic inflammation, with resolution through a psoriasis-like phenotype. Together, these findings link GAS infection to the CD1a pathway and show that GAS infection promotes the proliferation and activation of CD1a-autoreactive T cells, with relevance to post-streptococcal disease, including the pathogenesis and treatment of psoriasis.

Psoriasis: A Primer for General Physicians

Psoriasis is a multisystem, polygenic, inflammatory condition that typically causes changes in the skin. Although there is a significant genetic component, environmental factors like infections can have a significant impact on triggering the disease. A major part of the pathogenesis of psoriasis is played by the Interleukin (IL) IL23/IL17 axis along with the immune-related cells mainly macrophages and dendritic cells (DCs). Additionally, the role of various cytokines along with the toll-like receptors has also been pointed out in immunopathogenesis. These have been supported by the efficacy of biological therapies including TNF alpha inhibitors and inhibitors of IL17 and IL23. We have summarized the topical as well as systemic therapies for psoriasis including biologics. The article throws light on a few emerging therapeutic options like modulators of sphingosine 1-phosphate receptor 1 and Rho-associated kinase 2 inhibitors.

Intranasal streptococcal infection exacerbates psoriasis-like dermatitis via the induction of skin tissue-resident memory T cells

Recurrent streptococcal tonsillitis exacerbates psoriasis. Studies have indicated that T cells responding to streptococcal antigens in the skin are involved in the pathogenesis of the disease. However, a direct link between streptococcal tonsillitis and psoriasis has not been evidenced. In the present study, the impact of intranasal (i.n.) streptococcal infection on psoriasis was investigated using the imiquimod (IMQ) psoriasis mouse model. The results showed that repeated i.n. infection with group A Streptococcus (GAS) induced a robust and persistent Th17 response in the nasal-associated lymphoid tissue (NALT) and exacerbated IMQ-mediated psoriatic skin lesions. ELISpot and flow cytometry analyses revealed that GAS-reactive tissue-resident memory T cells (T_RM) were present in the skin of GAS-infected mice and produced IL-17/IL-23 axis cytokines in response to IMQ, compared to mice uninfected with GAS. In addition, i.n. infection with Streptococcus pneumoniae (Sp), a pathogen not associated with the development of psoriasis, also induced a persistent Th17 response in NALT but did not exacerbate IMQ-induced psoriatic inflammation nor elicited Sp-specific T cells in the skin. The results provide in vivo evidence that GAS-associated psoriasis is dependent on the skin GAS-specific T_RM cells induced by GAS nasopharyngeal infection and can be later activated by environmental triggers, leading to psoriatic inflammation. Reducing the reservoir of Th17 cells, which are source of skin T_RM cells, may constitute a promising treatment for psoriasis.

Mechanisms of skin autoimmunity: Cellular and soluble immune components of the skin

Autoimmune diseases are driven by either T cells or antibodies reacting specifically to 1 or more self-antigens. Although a number of self-antigens associated with skin diseases have been identified, the causative antigen(s) remains unknown in the great majority of skin diseases suspected to be autoimmune driven. Model diseases such as pemphigus, dermatitis herpetiformis, and more recently psoriasis have added greatly to our understanding of skin autoimmunity. Depending on the dominant T- or B-cell phenotype, skin autoimmune diseases usually follow 1 of 6 immune response patterns: lichenoid, eczematous, bullous, psoriatic, fibrogenic, or granulomatous. Usually, skin autoimmunity develops as a consequence of several events-an altered microbiome, inherited dysfunctional immunity, antigens activating innate immunity, epigenetic modifications, sex predisposition, and impact of antigens either as neoantigen or through molecular mimicry. This review summarizes currently known antigens of skin autoimmune diseases and discusses mechanisms of skin autoimmunity.

Animal models of psoriasis-highlights and drawbacks

Research into the pathophysiology of psoriasis remains challenging, because this disease does not occur naturally in laboratory animals. However, specific aspects of its complex immune-pathology can be illuminated through transgenic, knockout, xenotransplantation, immunological reconstitution, drug-induced, or spontaneous mutation models in rodents. Although some of these approaches have already been pursued for more than 5 decades and even more models have been described in recent times, they have surprisingly not yet been systematically validated. As a consequence, researchers regularly examine specific aspects that only partially reflect the complex overall picture of the human disease. Nonetheless, animal models are of great utility to investigate inflammatory mediators, the communication between cells of the innate and the adaptive immune systems, the role of resident cells as well as new therapies. Of note, various manipulations in experimental animals resulted in rather similar phenotypes. These were called "psoriasiform", "psoriasis-like" or even "psoriasis" usually on the basis of some similarities with the human disorder. Xenotransplantation of human skin onto immunocompromised animals can overcome this limitation only in part. In this review, we elucidate approaches for the generation of animal models of psoriasis and assess their strengths and limitations with a certain focus on more recently developed models.

The heartbreak of psoriasis: a review of cardiovascular risk in patients with psoriasis

Psoriasis is a common, chronic, autoimmune condition characterized by excessive growth and differentiation of keratinocytes that affects approximately 1% to 3% of the general population in the United States. Mounting evidence has led to an increasing awareness that psoriasis as a disease is more than "skin deep" and that it shares systemic manifestations with other chronic inflammatory diseases such as Crohn's and diabetes mellitus. Recent studies have not only shown an increased prevalence of cardiovascular risk factors in psoriasis but have also identified psoriasis as an independent risk factor for developing cardiovascular disease. This calls for an approach beyond managing traditional risk factors, which remain the standard guidelines at present.

Effect of tonsillectomy on psoriasis: a systematic review

BACKGROUND

Streptococcal infection is associated with psoriasis onset in some patients. Whether tonsillectomy decreases psoriasis symptoms requires a systematic review of the literature.

OBJECTIVE

We sought to determine whether tonsillectomy reduces psoriasis severity through a comprehensive search of over 50 years of literature.

METHODS

We searched MEDLINE, CINAHL, Cochrane, EMBASE, Web of Science, and OVID databases (from August 1, 1960, to September 12, 2013) and performed a manual search of selected references. We identified observational studies and clinical trials examining psoriasis after tonsillectomy.

RESULTS

We included data from 20 articles from the last 53 years with 545 patients with psoriasis who were evaluated for or underwent tonsillectomy. Of 410 reported cases of patients with psoriasis who underwent tonsillectomy, 290 experienced improvement in their psoriasis. Although some patients who underwent tonsillectomy experienced sustained improvement in psoriasis, others experienced psoriasis relapse after the procedure.

LIMITATIONS

Fifteen of 20 publications were case reports or series that lacked control groups. Publication bias favoring reporting improved cases needs to be considered.

CONCLUSION

Tonsillectomy may be a potential option for patients with recalcitrant psoriasis associated with episodes of tonsillitis. Studies with long-term follow-up are warranted to determine more clearly the extent and persistence of benefit of tonsillectomy in psoriasis.

Cardiovascular risk and psoriasis: beyond the traditional risk factors

Psoriasis is an autoimmune disease resulting in plaques of the skin. Similar to atherosclerosis, inflammation is integral to the initiation and propagation of plaque development. Mounting evidence has emerged demonstrating that psoriasis not only is associated with increased prevalence of cardiovascular risk factors, but also is an independent risk factor for the development of cardiovascular disease. Systemic therapies for moderate to severe psoriasis can increase the cardiovascular risk. Despite the evidence that psoriasis is an independent risk factor for cardiovascular disease, current guidelines only address managing traditional risk factors. An interdisciplinary approach is needed to find the necessary steps beyond classic risk reduction and detection of early cardiovascular disease in patients with psoriasis, as well as to develop a cardiovascular disease preventive regimen.

The association of sore throat and psoriasis might be explained by histologically distinctive tonsils and increased expression of skin-homing molecules by tonsil T cells

Recent studies have highlighted the involvement of the palatine tonsils in the pathogenesis of psoriasis, particularly among patients with recurrent throat infections. However, the underlying immunological mechanism is not well understood. In this study we confirm that psoriasis tonsils are infected more frequently by β-haemolytic Streptococci, in particular Group C Streptococcus, compared with recurrently infected tonsils from patients without skin disease. Moreover, we show that tonsils from psoriasis patients contained smaller lymphoid follicles that occupied a smaller tissue area, had a lower germinal centre to marginal zone area ratio and contained fewer tingible body macrophages per unit area compared with recurrently infected tonsils from individuals without skin disease. Psoriasis patients' tonsils had a higher frequency of skin-homing [cutaneous lymphocyte-associated antigen (CLA(+) )] CD4(+) and CD8(+) T cells, and this correlated significantly with their frequency of blood CLA(+) T cells. The psoriasis patients also had a higher frequency of tonsil T cells expressing the interleukin (IL)-23 receptor that was expressed preferentially by the CLA(+) T cell population. In contrast, recurrently infected tonsils of individuals without skin disease had a higher frequency of tonsil T cells expressing the activation marker CD69 and a number of chemokine receptors with unknown relevance to psoriasis. These findings suggest that immune responses in the palatine tonsils of psoriasis patients are dysregulated. The elevated expression of CLA and IL-23 receptor by tonsil T cells may promote the egression of effector T cells from tonsils to the epidermis, suggesting that there may be functional changes within the tonsils, which promote triggering or exacerbation of psoriasis.

New insights of T cells in the pathogenesis of psoriasis

Psoriasis is one of the most common immune-mediated chronic, inflammatory skin diseases characterized by hyperproliferative keratinocytes and infiltration of T cells, dendritic cells, macrophages and neutrophils. Although the pathogenesis of psoriasis is not fully understood, there is ample evidence suggesting that the dysregulation of immune cells in the skin, particularly T cells, plays a critical role in psoriasis development. In this review, we mainly focus on the pathogenic T cells and discuss how these T cells are activated and involved in the disease pathogenesis. Newly identified 'professional' IL-17-producing dermal γδ T cells and their potential role in psoriasis will also be included. Finally, we will briefly summarize the recent progress on the T cell and its related cytokine-targeted therapy for psoriasis treatment.

Intracellular inflammatory sensors for foreign invaders and substances of self-origin

In order to survive, all organisms must recognize and eliminate foreign invaders such as infectious pathogens, chemicals, ultraviolet rays, metabolites and damaged or transformed self-tissues, as well as allogenic organs in cases of transplantation. Recent research in innate immunity has elucidated that there are versatile inflammatory sensors on spatiotemporal 'sentry duty' that recognize substances derived from both 'nonself' and 'self', e.g., Toll-like receptors, retinoic acid-inducible gene-I-like receptors, nucleotide oligomerization domain-like receptors and c-type lectin receptors. Having acquired high-level functions through the development of multiple molecules, higher organisms have established both extracellular and intracellular sensors that can discriminate danger-associated molecular patterns from promiscuous, but biologically similar, molecular patterns. In addition, 'loss-of-function' or 'gain-of-function' mutations in these inflammatory sensors have been linked (at least in part) with the etiology and severity of autoimmune diseases, autoinflammatory diseases and immunocompromised diseases in humans. Further studies focusing on the role of these inflammatory sensors in the development of immune disorders would highlight new avenues for the development of novel diagnostic and therapeutic applications with regard to these diseases.

In vitro screening for putative psoriasis-specific antigens among wheat proteins and peptides

BACKGROUND

Patients with psoriasis who had raised IgG and/or IgA antigliadin antibodies showed clinical improvement in a trial with a gluten-free diet. The selection of patients for the diet treatment was based on the presence of specific antibodies, i.e. the result of humoral immunity.

OBJECTIVES

As psoriasis is now considered to be a T cell-mediated disease we decided to challenge peripheral blood mononuclear cells (PBMCs) in vitro from randomly selected patients with well-defined wheat proteins/peptides to explore the possibility of identifying a specific antigen with T cell activating properties in a subgroup of patients.

METHODS

PBMCs from 37 patients (20 female and 17 male; mean age 49years) and 37 healthy controls (12 female and 25 male; mean age 57years) were included. Not all patients participated in all experiments. The PBMCs were exposed in vitro with the following wheat proteins/peptides in various concentrations: total albumins, 0·28 α-amylase inhibitor and the synthetic peptides, p31-43, p57-68 and p62-75, based on coeliac-active sequences of α-gliadin. The proliferative response was measured as counts per minute after the cells had been pulsed with methyl-(3) H-thymidine.

RESULTS

Albumin, α-amylase inhibitor, p31-43 and p57-68 elicited a significant response in both patients and controls but showed no differences between the groups. The response induced by the α-amylase inhibitor was higher than that induced by the albumin fraction and the p31-43 and p57-68 peptides. At a concentration of 25μgmL(-1) , five of 36 patients with psoriasis responded positively to the p62-75 peptide and none of the 33 controls, using a stimulation index of 2·4 as the cut-off level (P<0·05). These five patients did not show clinical features that differed from the remaining patients. Among the responding patients the relative number of CD4+ cells increased in some but not all after in vitro challenge with the albumins, 0·28 α-amylase inhibitor, and p62-75. These antigens could also induce in vitro the expression of the homing antigen cutaneous lymphocyte antigen (CLA) in a few patients and controls.

CONCLUSIONS

The wheat protein antigens, especially the p62-75 peptide, might be of interest in a subgroup of patients with psoriasis.

Psoriasis--as an autoimmune disease caused by molecular mimicry

Psoriasis is strongly associated with streptococcal throat infection, and patients have increased occurrence of such infections. Psoriatic lesional T cells are oligoclonal, and T cells recognizing determinants common to streptococcal M-protein and keratin have been detected in patients' blood. We propose that CD8(+) T cells in psoriatic epidermis respond mainly to such determinants, whereas CD4(+) T cells in the dermis preferentially recognize determinants on the streptococcal peptidoglycan that might itself act as an adjuvant. The streptococcal association might reflect the concurrence of superantigen production promoting skin-homing of tonsil T cells, M-protein mimicking keratin determinants, and adjuvant effects of the peptidoglycan. Accordingly, improvement of psoriasis after tonsillectomy should be associated with fewer T cells that recognize keratin and streptococcal determinants.

HLA-Cw*0602 associates with a twofold higher prevalence of positive streptococcal throat swab at the onset of psoriasis: a case control study

Background

The influence of streptococcal infections in the pathogenesis of psoriasis is not yet understood. In vitro data suggest that streptococcal factors influence T-cell function in psoriasis in a HLA-dependent manner, but studies designed to measure the HLA-C/Streptococci interaction are lacking. In the present study, we hypothesized that there is a statistical interaction between the result of streptococcal throat cultures and the presence of the HLA-Cw*0602 allele in psoriasis patients.

Methods

We performed a case control study using the "Stockholm Psoriasis Cohort" consisting of patients consecutively recruited within 12 months of disease onset (Plaque psoriasis = 439, Guttate psoriasis = 143), matched to healthy controls (n = 454) randomly chosen from the Swedish Population Registry. All individuals underwent physical examination including throat swabs and DNA isolation for HLA-Cw*0602 genotyping.

The prevalence of positive streptococcal throat swabs and HLA-Cw*0602 was compared between patients and controls and expressed as odds ratios with 95% confidence intervals. Associations were evaluated separately for guttate and plaque psoriasis by Fisher's exact test.

Results

Regardless of disease phenotype, the prevalence of positive streptococcal throat swabs in HLA-Cw*0602 positive patients was twice the prevalence among HLA-Cw*0602 negative patients (OR = 5.8 C.I. = 3.57–9.67, p < 0.001), while no difference was observed among Cw*0602 positive versus negative controls.

The corresponding odds ratios for the guttate and plaque psoriasis phenotypes were 3.5 (CI = 1.5–8.7, p = 0.01) and 2.3 (CI = 1.0–5.1, p = 0.02) respectively.

Conclusion

These findings suggest that among HLA-Cw*0602 positive psoriasis patients, streptococci may contribute to the onset or exacerbation of the inflammatory process independent of the disease phenotype. However, studies on the functional interaction between HLA-C and streptococcal factors are needed.

Microbiological findings in subjects with asymptomatic oral lichen planus: a cross-sectional comparative study

BACKGROUND

The bacterial colonization of the oral mucosa was evaluated in patients with asymptomatic oral lichen planus (OLP) and compared to the microbiologic status in mucosally healthy subjects.

METHODS

Bacteria from patients with clinically and histopathologically diagnosed OLP from the Stomatology Service, Department of Oral Surgery and Stomatology, School of Dental Medicine, University of Bern, were collected with a non-invasive swab system. Samples were taken from OLP lesions on the gingiva and from non-affected sites on the contralateral side of the mouth. The control population did not have OLP and was recruited from the student clinic. All samples were processed with the checkerboard DNA-DNA hybridization method using well-defined bacterial species for the analysis.

RESULTS

Significantly higher bacterial counts of Bacteroides ureolyticus (P = 0.001), Dialister species (sp.) (P = 0.006), Staphylococcus haemolyticus (P = 0.007), and Streptococcus agalactiae (P = 0.006) were found in samples taken from OLP lesions compared to sites with no clinical evidence of OLP. Significantly higher bacterial counts were found for Capnocytophaga sputigena, Eikenella corrodens, Lactobacillus crispatus, Mobiluncus curtisii, Neisseria mucosa, Prevotella bivia, Prevotella intermedia, and S. agalactiae at sites with lesions in subjects with OLP compared to sites in control subjects (P <0.001).

CONCLUSIONS

Microbiologic differences were found between sites with OLP and sites in subjects without a diagnosis of OLP. Specifically, higher counts of staphylococci and S. agalactiae were found in OLP lesions.

Management of childhood psoriasis

Treating children with psoriasis represents one of the most rewarding yet constantly challenging endeavors in dermatology. These patients require time, energy, enthusiasm, empathy, and current, comprehensive knowledge of the unique clinical presentations in children and available therapies, including clinical action spectrum, mechanism of action, potential toxicity, and monitoring. Longitudinal trials examining the epidemiology and natural history of psoriasis, as well as the safety and efficacy of current and emerging treatments, are desperately needed in the pediatric population. Partner with the patient, family, and other multidisciplinary providers to form an educational and therapeutic alliance. Early in the course of disease, schedule frequent visits for reinforcement of the therapeutic plan, education, clinical and treatment monitoring, and support. As the disease and the patient's physical, psychosocial and emotional level of functioning evolve, so too will the requirement for follow-up and monitoring. Patient advocacy and education groups, such as the National Psoriasis Foundation (www.psoriasis.org; 800-723-9166) are excellent resources and can serve as an extension of your comprehensive care.

High prevalence of concomitant anogenital lichen sclerosus and extragenital psoriasis in adult women

OBJECTIVE

To analyze the prevalence of lichen sclerosus and psoriasis in gynecologic patients.

METHODS

The prevalence of lichen sclerosus and psoriasis individually, as well as the prevalence of both diseases in the same patient, was evaluated among 2,800 women attending a primary care gynecology practice for annual routine gynecologic examinations. The incidence of lichen sclerosus (new diagnosis of lichen sclerosus per year/population at risk) was calculated for the last 5 years.

RESULTS

Two hundred (7.1%) women had a biopsy-proven anogenital lichen sclerosus, and 57 women (2%) had an extragenital psoriasis vulgaris. Fifteen women had both diseases (0.5%). The prevalence of psoriasis in lichen sclerosus patients was 7.5% (15 of 200; 95% confidence interval 4.3-12.1%) compared with 1.6% (42 of 2,600) in the non-lichen sclerosus patient group. Lichen sclerosus was diagnosed in 13 of 15 psoriasis patients at an average of 19.5 years after the diagnosis of psoriasis at the age of 48 years (range 30-70 years). The incidence rates of lichen sclerosus for the last 5 years were 0.5% in 2002, 0.7% in 2003 and 2004, 1.9% in 2005, and 1.8% in 2006.

CONCLUSION

The prevalence of psoriasis in lichen sclerosus patients (7.5%) is higher than in the general population and among the non-lichen sclerosus patients in this practice (1.6%). This association may result from a similar immune dysregulation in these women.

LEVEL OF EVIDENCE

II.

Immunopathogenesis of psoriasis

Investigations into the cause and treatment of psoriasis remain at the forefront of basic and applied clinical research efforts around the world. The purpose for this review is to provide an up-to-date synopsis of recent progress in ten sections exploring the immunological and inflammatory basis for psoriasis. Given the breadth of this topic in investigative skin biology and frequent paradigm shifts, it should not be surprising that the bibliography contains more than 150 references; many of which have been published in the last 5 years. Whereas considerable progress has been made into the immunopathogenesis of psoriasis, many fundamentally important questions remain regarding the role of cells located in both epidermal and dermal compartments. Attempts to characterize various animal models of psoriasis, delineation of the mechanism of action for biological agents, and consideration of molecular links between skin inflammation and various extracutaneous comorbidities are likely to continue challenging investigators and clinicians for many years to come.

Peptidoglycan: a major aetiological factor for psoriasis?

Peptidoglycan (PG), a major cell-wall component of Gram-positive bacteria, has been detected within antigen-presenting cells in various inflammatory conditions, including psoriasis. The additional presence of T-helper 1 cells specific for streptococcal or staphylococcal PG in psoriasis skin lesions implicates PG as an important T-cell stimulator for the disease. PG is a major target for the innate immune system, and associations between genetic polymorphisms of recognition receptors for PG and various auto-inflammatory diseases have been identified. The location of these genes within four linkage sites for psoriasis raises the possibility that an altered innate recognition of PG might contribute to the enhanced T-cell response to the bacterial antigen. These observations suggest that PG is a major aetiological factor for psoriasis and emphasize the importance of PG in bacterial-infection-induced inflammatory disease.

Psoriasis--a possible candidate for vaccination

The clinical association of streptococcal infections and psoriasis is well established. The recent finding that the T cells in psoriasis skin respond to streptococcal peptidoglycan now suggests a pathway for an adaptive immune response to the streptococcal organism. These observations may allow for possible vaccines to be developed for psoriasis.

Peripheral blood mononuclear cells proliferation and Th1/Th2 cytokine production in response to streptococcal M protein in psoriatic patients

BACKGROUND

Psoriasis is a chronic skin disease that is probably a T cell-mediated autoimmune condition which is strongly associated with streptococcal throat infections. Although some groups have associated the involved response with different streptococcal antigens, M protein has been described as the major virulence factor of Streptococcus pyogenes. Thus, it is necessary to describe some features of the cellular responses to this streptococcal antigen.

METHODS

Proliferation and Th1/Th2 cytokine production of peripheral blood mononuclear cells (PBMC) in response to total soluble extracts from type M5 S. pyogenes with (TSE37Sp) and without (M(-)TSESp) M protein were analyzed in 10 psoriatic patients and 10 healthy controls.

RESULTS

PBMC from both patients and controls proliferated to both extracts. Responses to M(-)TSESp were significantly lower than those to TSE37Sp (P < 0.05). PBMC IL-2 and gammaIFN production after TSE37Sp stimulus was much higher than after M(-)TSESp antigenic stimulation in both groups (P < 0.05). Meanwhile, IL-4 production was quite low in both groups and in response to both extracts. We found a differential production of IL-10 between groups. PBMC from healthy controls responded to TSE37Sp with a much higher production of this cytokine as compared to the responses showed to M(-)TSESp while the cells from psoriatic patients responded without differences in the production of IL-10.

CONCLUSION

Results obtained suggest an important Th1 response to M protein in psoriatic patients which could be associated with the cellular responses involved in psoriasis, while healthy subjects respond in a probably non-Th2 IL-10 producing regulatory T cells fashion.

Antibodies against human muscle enolase recognize a 45-kDa bacterial cell wall outer membrane enolase-like protein

Enolase, is a glycolytic enzyme ubiquitous in higher organisms, where it forms tissue specific dimers of isoforms, also found in the cytoplasm of fermentative bacteria. The aim of this work was to identify enolase-like proteins in the cell wall of some Gram-negative bacteria using antibodies against human beta-enolase, an isoenzyme specific to skeletal and heart muscles. Cell wall outer membrane protein (OMP) preparations were obtained from 9 strains of Enterobacteriaceae and one of Pseudomonas aeruginosa. Specific enzymatic enolase activity was detected in the supernatant fractions of cytosolic and inner membrane material, but not in purified OMP preparations. Rabbit polyclonal antibodies specific against human beta-enolase were prepared and purified using immobilized human beta-enolase in affinity chromatography. In SDS-polyacrylamide gel electrophoresis and immunoblotting assay of purified OMP preparations, rabbit anti-enolase antibody interacted specifically with a few OMPs, of which a 45-kDa band also interacted with human sera of patients presenting Buerger disease and atherosclerosis. The most distinct interaction of human sera was observed with a 45-kDa OMP of Klebsiella pneumoniae. This protein was further isolated from K. pneumoniae cell mass in two ways, namely preparative SDS-polyacrylamide gel electrophoresis and specific affinity chromatography using immobilized affinity-purified rabbit antibody raised against human beta-enolase. The data obtained from tandem mass spectrometry tryptic peptide analysis and sequence comparison of human and bacterial enolases using protein databases, could reveal the similarity in the epitopes between membrane enolase-like protein from Klebsiella and human beta-enolase. The results show that the protein present in all studied strains has a common epitope on human beta-enolase. These data raise the question whether such a bacterial protein might be a marker for detecting and monitoring damage to skeletal and heart muscles.

Incidental detection of S. pyogenes-DNA in psoriatic skin by PCR

Psoriasis vulgaris is a T cell-mediated autoimmune skin disease. First disease onset and disease worsening are often triggered by tonsillar infection with Streptococcus pyogenes. Here we demonstrate the incidental detection of S. pyogenes DNA in samples of different biological origin from patients with chronic plaque-type psoriasis by PCR. These findings may support the model of molecular mimicry in psoriasis pathogenesis.

HLA DR B1*04, *07-restricted epitopes on Keratin 17 for autoreactive T cells in psoriasis

BACKGROUND

Psoriasis is a T cell-mediated inflammatory skin disease. Recent evidence suggests that activated CD4+ helper T lymphocytes of the Th1 phenotype play an important role in the pathogenesis of the disease. For psoriatic autoreactive T cells, Keratin 17 is a major target antigen and an epitope containing ALEEAN sequence has been described, but other psoriasis-related epitopes are still unknown.

OBJECTIVE

To identify the HLA DR B1*04, *07-restricted T cell epitopes on Keratin 17.

METHODS

HLA DRB1*04, *07-restricted T cell epitope regions on Keratin 17 were predicted based on related software and internet servers. Keratin 17 gene was amplified from psoriatic epidermis and the proteins of the predicted epitope regions were expressed, identified and purified. T cells from psoriatic patients reacted in cultivation with peptide-major histocompatibility complex (p-MHC) compound, then the level of cell proliferation and the concentration of interferon-gamma in culture supernatant were detected. After the psoriasis-related epitope regions were narrowed down, the epitopes on them were predicted further. These epitopes were then expressed and validated by T cell response in vitro.

RESULTS

Four epitopes--S1 (118-132), S2 (169-183), S4 (323-337) and S4 (348-362) can stimulate the proliferation and interferon-gamma production of psoriatic T cells more effectively than other epitopes (p<0.01) and react weakly with the T cells from healthy volunteers (p>0.05).

CONCLUSION

Epitopes S1 (118-132), S2 (169-183), S4 (323-337) and S4 (348-362) are immunodominant DR B1-restricted T cell epitopes for psoriasis. Among them, S1 (118-132) contains the ALEEAN sequence while the others with different amino acid sequence have not been reported before. Further studies based on these peptides would provide a more complete understanding of the immunological basis of psoriasis.

Psoriasis: future research needs and goals for the twenty-first century

Psoriasis research is entering a new era. Progress in delineating immunogenetics and pathomechanisms of disease brings with it a need to understand fully the clinical spectrum of disease and integrate phenotype with genomics and proteomics. Involvement of patient groups and an understanding of the psychosocial aspects of psoriasis, particularly its significant impairment of quality of life, are keys to progress. The biologic revolution in therapy of inflammatory disease has embraced psoriasis bringing with it an urgent need for evidence-base, consensus on outcome measures, and long-term real-life studies.A concerted effort between academia, industry, and patients will take forward the understanding of, and therapy for, psoriasis.

Recent insights into the immunopathogenesis of psoriasis provide new therapeutic opportunities

Chronic and excessive inflammation in skin and joints causes significant morbidity in psoriasis patients. As a prevalent T lymphocyte-mediated disorder, psoriasis, as well as the side effects associated with its treatment, affects patients globally. In this review, recent progress is discussed in the areas of genetics, the immunological synapse, the untangling of the cytokine web and signaling pathways, xenotransplantation models, and the growing use of selectively targeted therapies. Since psoriasis is currently incurable, new management strategies are proposed to replace previous serendipitous approaches. Such strategic transition from serendipity to the use of novel selective agents aimed at defined targets in psoriatic lesions is moving rapidly from research benches to the bedsides of patients with this chronic and debilitating disease.

Recent insights into the immunopathogenesis of psoriasis provide new therapeutic opportunities

Chronic and excessive inflammation in skin and joints causes significant morbidity in psoriasis patients. As a prevalent T lymphocyte-mediated disorder, psoriasis, as well as the side effects associated with its treatment, affects patients globally. In this review, recent progress is discussed in the areas of genetics, the immunological synapse, the untangling of the cytokine web and signaling pathways, xenotransplantation models, and the growing use of selectively targeted therapies. Since psoriasis is currently incurable, new management strategies are proposed to replace previous serendipitous approaches. Such strategic transition from serendipity to the use of novel selective agents aimed at defined targets in psoriatic lesions is moving rapidly from research benches to the bedsides of patients with this chronic and debilitating disease.

Selective response of dermal Th-1 cells to 20-50 kDa streptococcal cell-wall proteins in chronic plaque psoriasis

We have recently described a dermal Th-1 subset in skin lesions of psoriasis which recognizes cell-wall extract isolated from group A streptococci (GAS). As a first step in the identification of the streptococcal proteins involved, dermal T-cell lines (TCL) cultured from the lesional skin of 12 human leucocyte antigen (HLA)-typed psoriasis patients were stimulated with GAS cell-wall extract and 14 fractions (MWt approximately 20-100 kDa) separated from the cell-wall extract by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and electroelution, stained for intracellular interferon-gamma(IFN-gamma) expression and analysed by flow cytometry. All the TCL responded to GAS cell-wall extract to varying extents (3.5-27.6% IFN-gamma+). This response was consistently directed against 20-50 kDa cell-wall fractions and inhibited by anti-HLA-DR antibody. TCL with higher responses to GAS cell-wall extract recognized a larger number of fractions within this range than the lower responder TCL. No difference between the level and pattern of response to the fractions was observed for TCL from HLA-DR7+ (n = 6) and HLA-DR7- (n = 6) individuals. This preliminary study has shown a selective response to lower MWt proteins expressed on GAS cell wall by skin Th-1 cells in psoriasis. Further studies are required to identify the proteins involved.