A Sporothrix spp. enolase derived multi-epitope vaccine confers protective response in BALB/c mice challenged with Sporothrix brasiliensis.

Sporotrichosis is a cosmopolitan mycosis caused by pathogenic species of Sporothrix genus, that in Brazil is often acquired by zoonotic transmission involved infected cats with S. brasiliensis. Previous studies showed that the Sporothrix spp. recombinant enolase (rSsEno), a multifunctional protein with immunogenic properties, could be a promising target for vaccination against sporotrichosis in cats. Nevertheless, the considerable sequence identity (62%) of SsEno with its feline counterpart is a great concern. Here, we report the identification in silico, chemical synthesis and biological validation of six peptides of SsEno with low sequence identity to its cat orthologue. All synthesized peptides exhibit B-cell epitopes on the molecular surface of SsEno and proved to be highly reactive with the serum of infected mice with S. brasiliensis and sera of cats with sporotrichosis. Interestingly, our study revealed that anti-peptide sera did not react with the recombinant enolase from Felis catus (cats, rFcEno), thus, may not trigger autoimmune response in these felines if used as a vaccine antigen. The immunization with peptide mixture (PeptMix) formulated with Freund adjuvant (FA), induced high levels of antigen-specific IgG, IgG1 and IgG2b antibodies that conferred protection upon passive transference in infected BALB/c mice with S. brasiliensis. We also observed, that the FA+PeptMix formulation induced a Th1/Th2/Th17 cytokine profile ex vivo, associated with protecting effect against the experimental sporotrichosis. Our results suggest that the six SsEno-derived peptides here evaluated, could be used as safe antigens for the development of vaccine strategies against feline sporotrichosis, whether prophylactic or therapeutic.

Functional Characterization and Comparison of Plasmodium falciparum Proteins as Targets of Transmission-blocking Antibodies.

Plasmodium falciparum malaria continues to evade control efforts, utilizing highly specialized sexual-stages to transmit infection between the human host and mosquito vector. In a vaccination model, antibodies directed to sexual-stage antigens, when ingested in the mosquito blood meal, can inhibit parasite growth in the midgut and consequently arrest transmission. Despite multiple datasets for the Plasmodium sexual-stage transcriptome and proteome, there have been no rational screens to identify candidate antigens for transmission-blocking vaccine (TBV) development. This study characterizes 12 proteins from across the P. falciparum sexual-stages as possible TBV targets. Recombinant proteins are heterologously expressed as full-length ectodomains in a mammalian HEK293 cell system. The proteins recapitulate native parasite epitopes as assessed by indirect fluorescence assay and a proportion exhibits immunoreactivity when tested against sera from individuals living in malaria-endemic Burkina Faso and Mali. Purified IgG generated to the mosquito-stage parasite antigen enolase demonstrates moderate inhibition of parasite development in the mosquito midgut by the ex vivo standard membrane feeding assay. The findings support the use of rational screens and comparative functional assessments in identifying proteins of the P. falciparum transmission pathway and establishing a robust pre-clinical TBV pipeline.

Serum IgG2 antibody multi-composition in systemic lupus erythematosus and in lupus nephritis (Part 2): prospective study.

OBJECTIVES: Circulating anti-ENO1 and anti-H2A IgG2 have been identified as specific signatures of LN in a cross-over approach. We sought to show whether the same antibodies identify selected population of patients with LN with potentially different clinical outcomes. METHODS: Here we report the prospective analysis over 36 months of circulating IgG2 levels in patients with newly diagnosed LN (n=91) and SLE (n=31) and in other patients with SLE recruited within 2 years from diagnosis (n=99). Anti-podocyte (ENO1), anti-nucleosome (DNA, histone 2 A, histone 3) and anti-circulating proteins (C1q, AnnexinA1-ANXA1) IgG2 antibodies were determined by home-made techniques. RESULTS: LN patients were the main focus of the study. Anti-ENO1, anti-H2A and anti-ANXA1 IgG2 decreased in parallel to proteinuria and normalized within 12 months in the majority of patients while anti-dsDNA IgG2 remained high over the 36 months. Anti-ENO1 and anti-H2A had the highest association with proteinuria (Heat Map) and identified the highest number of patients with high proteinuria (68% and 71% respectively) and/or with reduced estimated glomerula filtration rate (eGFR) (58% for both antibodies) compared with 23% and 17% of anti-dsDNA (agreement analysis). Anti-ENO1 positive LN patients had higher proteinuria than negative patients at T0 and presented the maximal decrement within 12 months. CONCLUSIONS: Anti-ENO1, anti-H2A and anti-ANXA1 antibodies were associated with high proteinuria in LN patients and Anti-ENO1 also presented the maximal reduction within 12 months that paralleled the decrease of proteinuria. Anti-dsDNA were not associated with renal outcome parameters. New IgG2 antibody signatures should be utilized as tracers of personalized therapies in LN. TRIAL REGISTRATION: The Zeus study was registered at https://clinicaltrials.gov (study number: NCT02403115).

Serum IgG2 antibody multicomposition in systemic lupus erythematosus and lupus nephritis (Part 1): cross-sectional analysis.

OBJECTIVES: Serum anti-dsDNA and anti-nucleosome IgGs have been proposed as signatures for SLE and LN in limited numbers of patients. We sought to show higher sensitivity and specificity of the same antibodies with the IgG2 isotype and included IgG2 antibodies vs specific intracellular antigens in the analysis. METHODS: A total of 1052 SLE patients with (n = 479) and without (n = 573) LN, recruited at different times from the beginning of symptoms, were included in the study. Patients with primary APS (PAPS, n = 24), RA (RA, n = 24) and UCTD (UCTD, n = 96) were analysed for comparison. Anti-nucleosome (dsDNA, Histone2A, Histone3), anti-intracellular antigens (ENO1), anti-annexin A1 and anti-C1q IgG2 were determined by non-commercial techniques. RESULTS: The presence in the serum of the IgG2 panel was highly discriminatory for SLE/LN vs healthy subjects. Serum levels of anti-dsDNA and anti-C1q IgG2 were more sensitive than those of IgGs (Farr radioimmunoassay/commercial assays) in identifying SLE patients at low-medium increments. Of more importance, serum positivity for anti-ENO1 and anti-H2A IgG2 discriminated between LN and SLE (ROC T0-12 months), and high levels at T0-1 month were detected in 63% and 67%, respectively, of LN, vs 3% and 3%, respectively, of SLE patients; serum positivity for each of these was correlated with high SLEDAI values. Minor differences existed between LN/SLE and the other rheumatologic conditions. CONCLUSION: Nephritogenic IgG2 antibodies represent a specific signature of SLE/LN, with a few overlaps with other rheumatologic conditions. High levels of anti-ENO1 and anti-H2A IgG2 correlated with SLE activity indexes and were discriminatory between SLE patients limited to the renal complication and other SLE patients. TRIAL REGISTRATION: The Zeus study was registered at https://clinicaltrials.gov, NCT02403115.

Occurrence of major anti-retinal autoantibodies associated with paraneoplastic autoimmune retinopathy.

Autoantibodies (AAbs) against retinal antigens can be found in patients with cancer and unexplained vision loss unrelated to the cancer metastasis. Cancer-associated retinopathy (CAR) is a rare paraneoplastic visual syndrome mediated by AAbs. Our goal was to determine whether CAR patients with different malignancies have a specific AAb or repertoire of AAbs that could serve as biomarkers for retinal disease. We found AAbs against 12 confirmed retinal antigens, with α-enolase being the most frequently recognized. The significant finding of the study was a high incidence of anti-aldolase AAbs in colon-CAR, anti-CAII in prostate-CAR, and anti-arrestin in skin melanoma patients thus these AAbs could serve as biomarkers in the context of clinical presentation and could support the diagnosis of CAR. However, a lack of AAb restriction to any one antigenic protein or to one retinal cellular location makes screening for a CAR biomarker challenging.

Peptides of neuron specific enolase as potential ASD biomarkers: From discovery to epitope mapping.

Autism spectrum disorder (ASD) is an important health issue and affects 1 in 59 children in the US. Prior studies determined that maternal autoantibody related (MAR) autism is thought to be associated with ~23% of ASD cases. We previously identified seven MAR-specific autoantigens including CRMP1, CRMP2, GDA, LDHA, LDHB, STIP1, and YBX1. We subsequently described the epitope peptide sequences recognized by maternal autoantibodies for each of the seven ASD-specific autoantigens. The aim of the current study was to expand upon our previous work and identify additional antigens recognized by the ASD-specific maternal autoantibodies, as well as to map the unique ASD-specific epitopes using microarray technology. Fetal Rhesus macaque brain tissues were separated by molecular weight and a fraction containing bands between 37 and 45 kDa was analyzed using 2-D gel electrophoresis, followed by peptide mass mapping using MALDI-TOF MS and TOF/TOF tandem MS/MS. Using this methodology, Neuron specific enolase (NSE) was identified as a target autoantigen and selected for epitope mapping. The full NSE sequence was translated into 15-mer peptides with an overlap of 14 amino acids onto microarray slides and probed with maternal plasma from mothers with an ASD child and from mothers with a Typically Developing child (TD) (ASD = 27 and TD = 21). The resulting data were analyzed by T-test. We found 16 ASD-specific NSE-peptide sequences for which four sequences were statistically significant (p < 0.05) using both the t-test and SAM t-test: DVAASEFYRDGKYDL (p = 0.047; SAM score 1.49), IEDPFDQDDWAAWSK (p = 0.049; SAM score 1.49), ERLAKYNQLMRIEEE (p = 0.045; SAM score 1.57), and RLAKYNQLMRIEEEL (p = 0.017; SAM score 1.82). We further identified 5 sequences that were recognized by both ASD and TD antibodies suggesting a large immunodominant epitope (DYPVVSIEDPFDQDDWAAW). While maternal autoantibodies against the NSE protein are present both in mothers with ASD and mothers of TD children, there are several ASD-specific epitopes that can potentially be used as MAR ASD biomarkers. Further, studies including analysis of NSE as a target protein in combination with the previously identified MAR ASD autoantigens are currently underway.

Non-paraneoplastic autoimmune retinopathy that developed in fellow eye 10 years after onset in first eye: a case report.

BACKGROUND: Evidence-based criteria for the treatment of autoimmune retinopathy (AIR) have not been established. The pathology and clinical features of each antibody causing AIR, and its long-term course are still undetermined. We report our findings in a case of non-paraneoplastic AIR (npAIR) that developed in the fellow eye 10 years after the onset in the first eye. CASE PRESENTATION: Our patient had photophobia in both eyes and a rapidly progressing visual field defect in his right eye at the initial examination. He was diagnosed with non-paraneoplastic AIR based on the clinical findings and immunoblot analyses for anti-retinal antibodies, and he was treated with steroids. Ten years later, a visual field defect developed in the fellow eye, and a diagnosis of npAIR was made. Immunoblot analyses were positive for anti-α-enolase antibodies. He was treated with steroids, immunosuppressants, and plasma exchange. However, the response to the treatment was poor and both eyes eventually became blind. CONCLUSIONS: As best we know, this is the first case report of npAIR that developed in the fellow eye over 10 years after the development in the first eye. Long-term follow-up and a search for tumor lesions are necessary in cases of npAIR. Further understanding of the long-term course of AIR can contribute to an understanding of the pathology and treatment of npAIR.

Photoelectrochemical immunoassay platform based on MoS2 nanosheets integrated with gold nanostars for neuron-specific enolase assay.

MoS2 nanosheets were prepared by exfoliating MoS2 bulk crystals with ultrasonication in N-methylpyrrolidone and were integrated with gold nanostars (AuNS) to fabricate an AuNS/MoS2 nanocomposite. All nanomaterials were characterized by transmission electron microscope, scanning electron microscope, ultraviolet-visible spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. AuNS/MoS2 nanocomposites were coated onto a glassy carbon electrode (GCE) surface to construct a nanointerface for immobilizing neuron-specific enolase antibody (anti-NSE) thus forming a photoelectrochemical immunoassay system. AuNS can significantly promote the photoelectric conversion of MoS2 nanosheets improving the performance for a photoelectrochemical assay. Being illuminated with white light LED and controlling the potential at 0.05 V (vs. SCE), the photocurrent generated from anti-NSE(BSA)/AuNS/MoS2/GCE using 0.15 mol L-1 ascorbic acid as electron donor can be recorded with amperometry and used as an output signal for NSE quantitative assay. Under optimized experimental conditions, the photocurrent variation for the affinity-binding NSE is proportional to the logarithm of NSE concentration in the range 5.0 pg mL-1   to 1.5 ng mL-1 with a detection limit of 3.5 pg mL-1 (S/N = 3). The practicability of the PEC immunoassay system was evaluated by determining NSE in clinical serum samples. The recoveries ranged from 93.0 to 103% for the determination of NSE in serum samples with a standard addition method. The PEC immunoassay system possesses good accuracy for determining NSE in real samples. Graphical abstract.

Structural Insights into the Interactions of Candidal Enolase with Human Vitronectin, Fibronectin and Plasminogen.

Significant amounts of enolase-a cytosolic enzyme involved in the glycolysis pathway-are exposed on the cell surface of Candida yeast. It has been hypothesized that this exposed enolase form contributes to infection-related phenomena such as fungal adhesion to human tissues, and the activation of fibrinolysis and extracellular matrix degradation. The aim of the present study was to characterize, in structural terms, the protein-protein interactions underlying these moonlighting functions of enolase. The tight binding of human vitronectin, fibronectin and plasminogen by purified C. albicans and C. tropicalis enolases was quantitatively analyzed by surface plasmon resonance measurements, and the dissociation constants of the formed complexes were determined to be in the 10-7-10-8 M range. In contrast, the binding of human proteins by the S.cerevisiae enzyme was much weaker. The chemical cross-linking method was used to map the sites on enolase molecules that come into direct contact with human proteins. An internal motif 235DKAGYKGKVGIAMDVASSEFYKDGK259 in C. albicans enolase was suggested to contribute to the binding of all three human proteins tested. Models for these interactions were developed and revealed the sites on the enolase molecule that bind human proteins, extensively overlap for these ligands, and are well-separated from the catalytic activity center.

High levels of antibodies to citrullinated α-enolase peptide-1 (CEP-1) identify erosions and interstitial lung disease (ILD) in a Chinese rheumatoid arthritis cohort.

We evaluated the clinical performance of anti-CEP-1 in a Chinese rheumatoid arthritis (RA) cohort. A total of 264 subjects were tested, including 101 RA patients, 38 juvenile idiopathic arthritis (JIA) patients, 46 disease control (DC) and 79 healthy controls (HC). The presence of anti-CEP-1 in patients with RA, JIA, DCs and HC were 61.4%, 13.2%, 15.2% and 5.1%, respectively. Anti-CCP2 demonstrated the highest positive likelihood ratio of 10.11 in the diagnosis of RA, followed by RF (8.88) and anti-CEP-1 (5.82). Anti-CEP-1 positive RA patients displayed significantly higher DAS28 compared to anti-CEP-1 negative RA patients (p = .045). Significant associations were identified between anti-CEP-1 and joint erosions at anti-CEP-1 value of >124.78 U/ml (p = .0026) and between anti-CEP-1 and ILD at anti-CEP-1 value of >185.91 U/ml (p = .0222). Our findings indicate that anti-CEP-1 may not be able to replace anti-CCP2 for routine diagnosis for RA, but they may be helpful for subtyping of the disease.

Anti-α-enolase antibody combined with ß2 microglobulin evaluated the incidence of nephritis in systemic lupus erythematosus patients.

OBJECTIVE: Anti-α-enolase antibody (Ab) combined with ß2 microglobulin (ß2-MG) were investigated to predict the incidence of nephritis in systemic lupus erythematosus (SLE) patients. METHODS: Levels of serum anti-α-enolase Ab and urinary ß2-MG were detected in 115 SLE patients, 29 SLE patients with nephritis and 70 healthy controls by ELISA and immunoturbidimetry, respectively. Furthermore, the correlation between anti-α-enolase Ab combined with ß2-MG and the incidence of nephritis in SLE patients was evaluated by correlation analysis. RESULTS: The optical density value of serum anti-α-enolase Ab in SLE patients with nephritis (0.84) was greatly increased compared with SLE patients (0.76) or healthy controls (0.54). Moreover, the levels of urinary ß2-MG in SLE patients with nephritis (6.75 mg/L) were increased compared with SLE patients (3.45 mg/L) or healthy controls (1.48 mg/L). There was a positive correlation between the level of anti-α-enolase Ab and ß2-MG ( r = 0.754). Furthermore, anti-α-enolase Ab combined with ß2-MG for evaluating the incidence of nephritis in SLE patients had the best assessment of the effectiveness (area under the receiver operating characteristic curve (AUC): 92.7%) compared with only anti-α-enolase Ab (AUC: 80.9%) or ß2-MG (AUC: 84.5%). CONCLUSION: These data suggested that anti-α-enolase Ab may be a potential indicator for the prediction of nephritis in SLE patients.

A novel electrochemical strategy based on porous 3D graphene-starch architecture and silver deposition for ultrasensitive detection of neuron-specific enolase.

This work was aimed at designing a novel and ultrasensitive electrochemical immunoassay strategy to detect neuron-specific enolase (NSE) with a triple signal amplification strategy. A greatly enhanced sensitive detection of NSE was achieved by using porous three-dimensional graphene-starch architecture (3D-GNS) modified on the immunosensor's surface to construct a unique 3D immunoelectrode, which would greatly accelerate electron transfer and capture more protein molecules. 3D-GNS was prepared with starch as a crosslinking agent and stabilizer, which is biocompatible and environmentally friendly. Aggregation-free gold nanoparticle (AuNP) incorporated ordered mesoporous carbon-silica (OMCSi-Au) with good catalytic activity was synthesized as the tracing tag for labeling signal antibody (Ab2). After a sandwich-type immunoreaction, the OMCSi-Au labeled Ab2 was trapped on the surface of the immunosensor, and the high concentration of AuNPs with high dispersion greatly catalyzed the deposition of silver nanoparticles. The deposited silver nanoparticles (AgNPs) could be tested directly with anodic stripping voltammetric analysis (ASV) in potassium chloride solution to monitor the immunoreactions, which greatly enhanced the sensitivity of protein markers with a detection limit of 0.008 pg mL-1, and a linear range of 0.02 pg mL-1 to 35 ng mL-1 for neuron-specific enolase antigen. This proposed immunosensor displayed acceptable accuracy, good stability, and high sensitivity. Good results were also obtained in agreement with the enzyme-linked immunosorbent assay method, which provides greatly promising potential in clinical applications.

Simultaneous detection of carcinoembryonic antigen and neuron-specific enolase in human serum based on time-resolved chemiluminescence immunoassay.

In the clinical diagnosis of tumor, the immunological detection of single tumor markers may lead to errors and missed inspection. Therefore, it is necessary to establish an accurate and effective method for the simultaneous detection of multiple tumor markers. Thus, we developed a time-resolved chemiluminescence immunoassay (TRCLIA) to simultaneously detect carcinoembryonic antigen (CEA) and neuron-specific enolase (NSE) in human serum. Horseradish peroxidase (HRP) and alkaline phosphatase (ALP) were used as the detection probes to label the monoclonal antibodies of CEA and NSE by strain-promoted azide-alkyne cycloaddition (SPAAC), respectively. Based on a sandwich immunoassay, the targets in the samples were captured by antibodies immobilized on the surface of carboxylate-modified polystyrene microspheres (CPSMS) and sandwiched by other antibodies labeled with HRP and ALP. Since HRP and ALP had different dynamic characteristics, the CEA and NSE signals were recorded at 0.5 s and 20 min, respectively, and cross-interference could be avoided effectively. The whole signal detection processes could be completed in 20 min. The linear ranges of CEA and NSE were 0.1-64 ng mL-1 and 0.05-64 ng mL-1 and the limits of detection were 0.085 ng mL-1 and 0.044 ng mL-1 (S/N = 2), respectively. Also, 45 human serum samples obtained from patients having lung disease were tested by TRCLIA and commercial chemiluminescence enzyme-linked immunoassay (CLEIA) kits with good correlation. The correlation coefficients of CEA and NSE were 0.985 and 0.970, respectively. The results demonstrated a novel, effective, reliable and convenient TRCLIA method for the clinical diagnosis of CEA and NSE. The TRCLIA method has the potential to be an effective clinical tool for the early screening of lung cancer and can be applied in clinical diagnosis.

α-enolase is an antigenic target in primary Sjögren's syndrome.

OBJECTIVES: Although anti-cyclic citrullinated peptides antibodies are specific markers for rheumatoid arthritis (RA), they might be present in other diseases. Our aim was to assess the native or citrullinated antigens recognised by patients with primary Sjögren's syndrome (pSS) and to evaluate their association with clinical and serological features. METHODS: In an initial screening, we assessed the serum reactivity of 12 patients with pSS against native or in vitro citrullinated antigens of HEp-2 cells by immunoblotting. We identified a 47kDa band, which was preferentially recognised and corresponded to α-enolase. Thus, levels of IgA and IgG anti-native and citrullinated α-enolase antibodies were measured in 50 pSS patients, 20 RA patients and 20 healthy subjects (HS) by ELISA. RESULTS: We identified α-enolase as a predominant antigen recognised in pSS. These patients had higher levels of anti-citrullinated α-enolase IgG antibodies compared with RA or HS (p=0.003 and p<0.0001, respectively). Furthermore, there was an increase of IgG anti-citrullinated α-enolase vs IgG anti-non-citrullinated α-enolase antibodies in pSS patients (p=0.001), by contrast no difference was found in RA. The presence of IgA and IgG anti-non-citrullinated and anti-citrullinated α-enolase antibodies were not associated with any clinical manifestation whatsoever, including non-erosive arthritis among pSS, but an association of IgA anti-citrullinated α-enolase with anti-Ro/SSA antibodies was found. CONCLUSIONS: We characterised α-enolase as a dominant antigen in lysates of HEp- 2 cells in pSS. Nevertheless, their precise role in pSS remains to be elucidated.

Comparison of clinical characteristics in patients with Vogt-Koyanagi-Harada disease with and without anti-retinal antibodies.

PURPOSE: To compare the clinical characteristics of Vogt-Koyanagi-Harada (VKH) disease patients with and without anti-retinal antibodies (ARAs) that are frequently detected in autoimmune retinopathy. METHODS: Using immunoblot analyses, serum autoantibodies for recoverin, carbonic anhydrase II, and α-enolase were examined in 20 treatment-naïve patients with VKH disease. Clinical factors before and after systemic corticosteroid therapy, including best-corrected visual acuity (BCVA) and macular outer retinal morphology, were statistically compared between patients with VKH disease with and without ARAs. RESULTS: Serum ARAs were detected in 50.0% of patients with VKH disease. There were no significant differences in clinical factors between the two groups, including final BCVA, frequency of uveitis recurrence, and recovery of the macular ellipsoid zone after systemic corticosteroid therapy. CONCLUSIONS: Our results suggest that the detected ARAs did not influence visual outcomes, the chronicity of uveitis, or outer retinal morphology in patients with VKH disease.

Detection of serum anti-retinal antibodies in the Chinese patients with presumed autoimmune retinopathy.

PURPOSE: To explore the presence of serum anti-retinal antibodies (ARAs) in the Chinese patients with presumed autoimmune retinopathy (AIR). METHODS: Twenty-three Chinese patients with presumed AIR, disease controls including 40 RP patients, 22 bilateral uveitis patients, 18 acute zonal outer occult retinopathy (AZOOR) patients, and 30 healthy donors were included. Serum samples of all the subjects were obtained and analyzed for the presence of four ARAs including recoverin, α-enolase, carbonic anhydraseII (CAII), and collapsin response-mediated protein (CRMP)-5 by Western bolt assay. RESULTS: ARAs were present in the serum of either presumed AIR patients, disease control, or healthy donors. One or more ARAs were present in the 78.2% of presumed AIR while they were indicated in the 35.0% of RP patients (p < 0.01) and 33.3% of healthy donors (p < 0.01). The prevalence of ARAs in the bilateral uveitis and AZOOR was 63.3% and 100% respectively. Positive rate of α-enolase antibody present in the presumed AIR, disease control, and healthy donors was 73.9%, 47.5%, and 33.3% respectively. Positive rate of CAII antibody present above groups was 52.1%, 50%, and 33.3% respectively. Recoverin antibody seemed to be specifically present in the serum of patients with cancer-associated retinopathy. CONCLUSION: Presence of serum ARAs including recoverin, α-enolase, CAII, or CRMP-5 in the Chinese patients with presumed AIR occurred significantly more often than RP patients and healthy donors. Seropositivity of ARAs had diagnostic value for the presumed AIR but mere presence was not sufficient for the diagnosis due to identification of them in the healthy controls and other retinal diseases.

Immunome and immune complex-forming components of Brugia malayi identified by microfilaremic human sera.

Adult Brugia malayi proteins with high potential as epidemiological markers, diagnostic and therapeutic targets, and/or vaccine candidates were revealed by using microfilaremic human sera and an immunoproteomic approach. They were HSP70, cytoplasmic intermediate filament protein, independent phosphoglycerate mutase, and enolase. Brugia malayi microfilaria-specific proteins that formed circulating immune complexes (ICs) were investigated. The IC-forming proteins were orthologues of hypothetical protein Bm1_12480, Pao retrotransposon peptidase family protein, uncoordinated protein 44, NAD-binding domain containing protein of the UDP-glucose/GDP-mannose dehydrogenase family which contained ankyrin repeat region, ZU5 domain with C-terminal death domain, C2 domain containing protein, and FLJ90013 protein of the eukaryotic membrane protein family. Antibodies to these proteins were not free in the microfilaremic sera, raising the possible role of the IC-forming proteins in an immune evasion mechanism of the circulating microfilariae to avoid antibody-mediated-host immunity. Moreover, detection of these ICs should be able to replace the inconvenient night blood sampling for microfilaria in an evaluation of efficacy of anti-microfilarial agents.

Memory T cells specific to citrullinated α-enolase are enriched in the rheumatic joint.

ACPA-positive rheumatoid arthritis (RA) is associated with distinct HLA-DR alleles and immune responses to many citrullinated self-antigens. Herein we investigated the T cell epitope confined within α-enolase326-340 in the context of HLA-DRB1*04:01 and assessed the corresponding CD4+ T cells in both the circulation and in the rheumatic joint. Comparative crystallographic analyses were performed for the native and citrullinated α-enolase326-340 peptides in complex with HLA-DRB1*04:01. HLA-tetramers assembled with either the native or citrullinated peptide were used for ex vivo and in vitro assessment of α-enolase-specific T cells in peripheral blood, synovial fluid and synovial tissue by flow cytometry. The native and modified peptides take a completely conserved structural conformation within the peptide-binding cleft of HLA-DRB1*04:01. The citrulline residue-327 was located N-terminally, protruding towards TCRs. The frequencies of T cells recognizing native eno326-340 were similar in synovial fluid and peripheral blood, while in contrast, the frequency of T cells recognizing cit-eno326-340 was significantly elevated in synovial fluid compared to peripheral blood (3.6-fold, p = 0.0150). Additionally, citrulline-specific T cells with a memory phenotype were also significantly increased (1.6-fold, p = 0.0052) in synovial fluid compared to peripheral blood. The native T cell epitope confined within α-enolase326-340 does not appear to lead to complete negative selection of cognate CD4+ T cells. In RA patient samples, only T cells recognizing the citrullinated version of α-enolase326-340 were found at elevated frequencies implicating that neo-antigen formation is critical for breach of tolerance.

Anti-citrullinated alpha enolase antibodies, interstitial lung disease and bone erosion in rheumatoid arthritis.

Objectives: RA is an articular chronic inflammatory disease that in a subgroup of patients can also present with extra-articular manifestations (EAMs). Despite intense investigation on this topic, reliable biomarkers for EAMs are lacking. In recent years several ACPAs, including those targeting anti-citrullinated alpha enolase peptide-1 (anti-CEP-1), have been identified in patients with RA. Data about the ability of anti-CEP-1 to predict the development of erosive disease are confliciting and no evidence concerning their possible association with EAMs in RA is currently available. The aim of this study was to investigate the prevalence and significance of anti-CEP-1 with regard to the association with erosive disease and EAMs in a large cohort of patients with RA. Methods: Anti-CCP and anti-CEP-1 antibodies have been assessed on serum samples of RA patients, healthy donors and patients with SpA using commercially available ELISA kits. Results: Anti-CEP-1 antibodies are detectable in over 40% of RA patients and are associated with erosive RA and with RA-associated interstitial lung disease (ILD). Conclusion: Anti-CEP-1 antibodies may represent a useful biomarker for RA-associated ILD and erosive disease to be employed in clinical practice.

Serum level of anti-α-enolase antibody in untreated systemic lupus erythematosus patients correlates with 24-hour urine protein and D-dimer.

Objective The objective of this report is to evaluate the prevalence and clinico-serological correlations of anti-α-enolase antibody (Ab) in patients with systemic lupus erythematosus (SLE). Methods Thirty-two untreated patients with SLE and 20 age- and sex-matched healthy controls were evaluated by rheumatologic examinations. The serum levels of anti-α-enolase Ab were measured by an enzyme-linked immunosorbent assay (ELISA). Clinical, biochemical and serological markers of disease activity were measured by standard laboratory procedure. Results The serum levels of anti-α-enolase Ab in SLE patients were higher significantly than those in healthy controls. Moreover, patients with lupus nephritis displayed significantly higher levels of serum anti-α-enolase Ab than those without renal involvement. The serum anti-α-enolase Ab levels were positively correlated with serum whole IgG and 24-hour urine protein and negatively correlated with serum D-dimer level. Conclusion These data suggest that anti-α-enolase Ab associates with active renal disease in SLE and might reflect a state of active autoimmunity and fibrinolysis inhibition.