In vitro characterization of an acetylcholine receptor–transferrin fusion protein for the treatment of myasthenia gravis

SHG2210, a fusion protein containing the N-terminus of human nicotinic acetylcholine receptor α (AchR-α; aa1-210) and human transferrin (TF), was characterized as a potential therapeutic for myasthenia gravis (MG) caused predominately by α subunit autoantibodies. SHG2210 was shown to be able to bind to α subunit autoantibodies and the TF receptor (TFR). SHG2210 and SHG2210–anti-AchR antibody complex are internalized through TFR-mediated endocytosis. The SHG2210 and SHG2210–anti-AchR antibody complex is present in Lamp1-positive lysosomal compartments after internalization; however, neither SHG2210 nor SHG2210–antibody complex is present in Rab11-positive recycling endosomes. SHG2210 bound to α subunit of AChR autoantibodies may be cleared by the lysosome, resulting in short cellular half-life relative to SHG2210. SHG2210 is shown to have a protective effect on antigenic modulation of the AChR induced by serum from select patients with MG, suggesting that a fusion protein approach may be an effective therapeutic for treating MG.     

Injection of inactive Bordetella pertussis and complete Freund’s adjuvant with Torpedo californica AChR increases the occurrence of experimental autoimmune myasthenia gravis in C57BL/6 mice

An animal model of myasthenia gravis (MG), termed experimental autoimmune MG (EAMG), is an important tool for investigations of disease mechanisms and/or methods of treatment for this disease. EAMG can be induced in C57BL/6 (B6, H-2^b) mice by 2–3 times injections at 4 weeks intervals with Torpedo californica (t) acetylcholine receptor (AChR) in complete Freund’s adjuvant (CFA). However, the protocol especially with a two-injection schedule occasionally produces a poor incidence of EAMG. We have investigated the efficacy of the additional adjuvant, inactive organisms of Bordetella pertussis (iBP), on the induction with a two-injection schedule. In a group immunized with tAChR in CFA?+?iBP, 76% of mice developed EAMG (average grade in exercise test, 1.02). Whereas, 46% of mice were found EAMG-positive (average grade, 0.73) in a group injected with tAChR/CFA alone. Thus, the combined use of CFA and iBP significantly increased both the occurrence and severity of clinical MG in the immunized mice. This was accompanied by higher antibody (Ab) and T-cell responses to tAChR. The effect on disease occurrence of the iBP use in a three-injection protocol was also described.     

Anti-neutrophil cytoplasmic antibodies target sequential functional proteinase 3 epitopes in the sera of patients with Wegener’s granulomatosis

Many patients with Wegener’s granulomatosis (WG) have anti-neutrophil cytoplasmic antibodies (c-ANCA). Aside from being a diagnostic marker, these autoantibodies may play roles in disease pathogenesis. Proteinase 3 (PR3) is the primary target of c-ANCA in WG patient sera. Of 60 c-ANCA-positive patients, 10 patients were selected for detailed humoral epitope analysis, contingent upon serum availability, using samples with positive levels of anti-PR3 by enzyme-linked immunosorbent assay (ELISA). Sequential epitope specificities of anti-PR3 antibodies detected by screening the maximally overlapping solid-phase octapeptides of PR3 showed seven major common antigenic targets bound by WG patient sera. These include novel and previously identified sequential PR3 epitopes bound by c-ANCA. B cell epitope prediction algorithms identified all or part of the seven defined epitopes. Several epitopes share sequence and structural proximity with functional sites, including the catalytic triad and proposed binding sites of other potential proteins [PR3 complementary peptide and soluble endothelial protein C receptor (sEPCR)]. Epitope 4 (VVLGAHNVRTQ) had the highest binding prevalence (90%) and epitope 2 (AQPHSRPYMAS) has the highest average reactivity of the antigenic regions. Epitope 4 includes the interaction site between sEPCR and PR3 which may serve as an important interaction to down-regulate inflammation. Epitopes 3, 5 and 7 are in direct proximity to amino acids that form the catalytic triad of the protein. c-ANCA targets both unique and previously known sequential PR3 peptides. This information may prove useful in understanding anti-PR3-mediated disease pathogenesis in systemic vasculitides.     

Anti-poly(G)·poly(C) antibodies in the serum of patients with systemic lupus erythematosus

Antibodies reacting with the double-stranded synthetic polyribonucleotide complex poly(G)·poly(C) have been demonstrated with various titers in the sera of patients with systemic lupus erythematosus (SLE). Despite a few exceptions, high poly(G)·poly(C) binding activity appears to be associated with clinically active disease. In contrast, there was no anti-poly(G)·poly(C) activity in the sera of normal subjects, or of patients with scleroderma, rheumatoid arthritis, and most of the sera from patients with mixed connective tissue disease. The poly(G)·poly(C) reactive antibodies were found to belong to the IgG class. They appeared to be different from those directed against poly(A)·poly(U) and poly(I)·poly(C). Competition experiments showed that in the majority of cases the most efficient inhibitor after poly(G)·poly(C) was total RNA from mammalian cells. Besides this cross-reactivity, the most striking feature of anti-poly(G)·poly(C) antibodies was their wide heterogeneity, each serum possessing its own specificity.     

Elevated immunoglobulin G antibodies to the proline-rich amino-terminal region of Epstein-Barr virus nuclear antigen-2 in sera from patients with systemic connective tissue diseases and from a subgroup of Sjögren's syndrome patients with pulmonary involvements

Associations of Epstein-Barr virus (EBV) and autoimmune diseases have been hypothesized. We have analysed IgG antibodies to EBV nuclear antigen (EBNA)-2 in sera from Japanese patients with autoimmune systemic connective tissue diseases (CTD), exemplified by systemic lupus erythematosus (SLE), primary Sjogren's syndrome (SS), rheumatoid arthritis (RA), systemic sclerosis (SSc) and secondary SS (classical CTDs complicated with SS). An enzyme-linked immunosorbent assay (ELISA) which uses glutathione-S-transferase polypeptides fused to EBV nuclear antigen (EBNA)-2 and EBNA-1 was developed. Ratios of IgG antibody reactivity to whole IgG concentrations of sera were calculated to normalize EBNA-2 and EBNA-1 antibody levels to the hypergammaglobulinaemia that occurs in CTD. The ELISA optical density OD(450) readings of IgG antibodies to both the amino-terminal aa 1-116 of EBNA-2 and carboxyl-terminal aa 451-641 of EBNA-1 were elevated significantly in patients with SLE, primary SS, RA, SSc and secondary SS when compared to EBNA-1. The OD readings were divided by serum IgG concentrations to normalize for the hypergammaglobulinaemia. The specific levels of IgG antibodies to the amino-terminal region of EBNA-2 were elevated in patients with SLE, primary SS or RA, as well as those with secondary SS complicated with SLE or RA. The EBNA-2 amino-terminal region contains a polyproline tract and a proline-rich sequence and has considerable amino acid sequence homology with many cellular proline-rich proteins. High ratios of EBNA-2 aa 1-116 to EBNA-1 aa 451-641 IgG antibody levels which probably suggest reactivation of EBV latent infection were associated significantly with pulmonary involvement in SS patients. These results are consistent with the hypothesis that the sequence similarity between the amino-terminal region of EBNA-2 and proline-rich cellular proteins is associated with pathogenesis in a subpopulation of CTD patients, possibly by the molecular mimicry-epitope shift mechanism.     

Surgical approaches for stage Ⅰ and Ⅱ thymoma-associated myasthenia gravis:feasibility of complete video-assisted thoracoscopic surgery (VATS) thymectomy in comparison with trans-sternal resection

Complete resection could be achieved in virtually all myasthenic patients with Masaoka stage Ⅰ and Ⅱ thymoma using the trans-sternal technique.Whether this is appropriate for minimally invasive approach is not yet clear.We evaluated the feasibility of complete video-assisted thoracoscopic surgery (VATS) thymectomy for the treatment of Masaoka stage Ⅰ and Ⅱ thymoma-associated myasthenia gravis,compared to conventional trans-sternal thymectomy.We summarized 33 patients with Masaoka stage Ⅰ and Ⅱ thymoma-associated myasthenia gravis between April 2006 and September 2011.Of these,15 patients underwent right-sided complete VATS (the VATS group) by using adjuvant pneuomomediastinum,comparing with 18 patients using the trans-sternal approach (the T3b group).No intraoperative death was found and no VATS case required conversion to median sternotomy.Significant differences between the two groups regarding duration of surgery and volume of intraoperative blood loss (P=0.001 and P < 0.001,respectively) were observed.Postoperative morbidities were 26.7% and 33.3% for the VATS and T3b groups,respectively.All 33 patients were followed up for 12 to 61 months in the study.The cumulative probabilities of reaching complete stable remission and effective rate were 26.7% (4/15) and 93.3% (14/15) in the VATS group,which had a significantly higher complete stable remission and effective rate than those in the T3b group (P=0.026 and P=0.000,respectively).We conclude that VATS thymectomy utilizing adjuvant pneuomomediastinum for the treatment of stage Ⅰ and Ⅱ thymoma-associated myasthenia gravis is technically feasible but deserves further investigation in a large series with long-term follow-up.     

Expression of BAFF (BLyS) in T cells infiltrating labial salivary glands from patients with Sjögren's syndrome

Primary Sj?gren's syndrome (pSS) is an autoimmune disorder characterized by lymphocytic infiltration of the salivary glands. Most of the infiltrating cells are T cells, but other features of the disease include polyclonal B-cell activation, systemic production of autoantibodies, and increased risk of developing B-cell non-Hodgkin's lymphoma. Recently, a new tumour necrosis factor, the B-cell activating factor (BAFF; also known as BLyS), has been implicated in the polyclonal activation of B cells. Using immunohistochemistry, this study evaluated BAFF expression in labial salivary gland biopsies from 14 patients with pSS, 14 normal controls, and two patients with sarcoidosis. Labial salivary gland samples from seven patients with pSS, seven controls, and one patient with sarcoidosis were double-stained using indirect immunofluorescence. RT-PCR analysis was also performed on lip biopsy samples from two patients and two controls. In all 14 pSS specimens, infiltrating inflammatory cells strongly expressed BAFF protein, as did some ductal epithelial cells, but acinar cells were negative. Some B cells were present in the vicinity of the BAFF-positive cells. In the 14 normal labial salivary glands, some ductal cells were moderately positive, but acinar cells were negative. In the labial salivary glands from the two patients with sarcoidosis, infiltrating lymphocytes were not stained. BAFF mRNA expression was confirmed by RT-PCR in salivary glands from pSS patients. Double immunofluorescence revealed T cells and macrophages to be the main cell types expressing BAFF in salivary glands from pSS patients. In conclusion, BAFF may be expressed by T cells at the site of autoimmune damage and could play a role in the pathogenesis of pSS, particularly by triggering the activation of self-antigen-driven autoimmune B cells.     

Expression of ADAMs (“a disintegrin and metalloprotease”) in the human lung

In view of the associations of “a disintegrin and metalloprotease” (ADAM) with respiratory diseases, we assessed the expression of various ADAMs in human lung tissue. Lung tissue was obtained from nine individuals who underwent surgery for lung cancer or underwent lung transplantation for emphysema. Also, 16HBE 14o- (human bronchial epithelial) and A549 (alveolar type II epithelium-like) cell lines were used. Immunohistochemistry was performed with antibodies recognizing different ADAM domains. The ADAMs were typically distributed over the bronchial epithelium. ADAM8 and ADAM10 were expressed diffusely in all layers of the epithelium. ADAM9, ADAM17, and ADAM19 were predominantly expressed in the apical part of the epithelium, and ADAM33 was predominantly and strongly expressed in basal epithelial cells. In smooth muscle, ADAM19 and ADAM17 were strongly expressed, as was ADAM33, though this expression was weaker. ADAM33 was strongly expressed in vascular endothelium. All ADAMs were generally expressed in inflammatory cells. The typical distribution of ADAMs in the lung, especially in the epithelium, is interesting and suggests a localized function. As most ADAMs are involved in release of (pro-) inflammatory mediators and growth factors, they may play an important role in the first line of defense and in initiation of repair events in the airways.     

Evaluating the conformation of recombinant domain I of β(2)-glycoprotein I and its interaction with human monoclonal antibodies

Pathogenic antiphospholipid antibodies (aPL) cause the antiphospholipid syndrome (APS) by interacting with domain I (DI) of beta-2-glycoprotein I (β(2)GPI). The aPL/β(2)GPI complex then exerts pathogenic effects on target cells. We previously described periplasmic bacterial expression of native and mutated variants of DI, and reported the presence of immunodominant epitopes at positions 8-9 (D8/D9) and position 39 (R39). Mutations at these positions strongly influenced the ability of recombinant DI to bind patient-derived IgG aPL and to inhibit pathogenic effects of these aPL in a mouse model of APS. We now describe an improved cytoplasmic bacterial expression system allowing higher yield of DI. We demonstrate that the nuclear magnetic resonance (NMR) spectra of a (15)N,(13)C-isotope-labelled sample of the recombinant DI protein exhibit properties consistent with the structure of DI in crystal structure of intact β(2)GPI. Mutations at D8/D9 and R39 had limited impact on the NMR spectrum of DI indicating maintenance of the overall fold of the DI domain. We investigated interactions between five variants of DI and ten monoclonal human IgG antibodies, all derived from the IgG aPL antibody IS4 by sequence manipulation and in vitro expression. Arginine residues at positions 100 and 100g in IS4V(H) CDR3 play a particularly important role in binding to DI, but this is unlikely to be due to electrostatic interactions with negatively charged amino acids on DI. Both the strength of binding to DI and the ability to discriminate different DI variants varies between the different IgG antibodies tested. There was no simple relationship between these binding properties and antibody pathogenicity.     

Expression of aquaporin-5 in and fluid secretion from immortalized human salivary gland ductal cells by treatment with 5-aza-2'-deoxycytidine: a possibility for improvement of xerostomia in patients with Sjögren's syndrome

The aim of the present study was to investigate the possibility that ductal cells, which preferentially survive and/or proliferate in Sj?gren's syndrome (SS) salivary glands of patients with SS, could acquire the functional expression of membrane water channel aquaporin-5 (AQP5). Thus, in this study, we demonstrate that an immortalized normal human salivary gland ductal cell (NS-SV-DC) line, lacking the expression of AQP5, acquires AQP5 gene expression in response to treatment with 5-aza-2'-deoxycytidine (5-Aza-CdR), a DNA demethylating agent. Confocal microscopic analysis revealed the localization of AQP5 expression mainly at the apical and lateral sides of the plasma membrane. The expressed AQP5 protein was functionally active because AQP5 expression resulted in a significant increase in the osmotically directed net fluid rate across monolayers of NS-SV-DC cells. By the analysis of bisulfite sequencing of CpG islands in the AQP5 promoter, hypermethylation within the consensus Sp1-binding sites was commonly observed in parental cell clones, whereas demethylation at the CGs, one in the second consensus Sp1 element and the other outside of the third consensus Sp1 element in the AQP5 promoter, was detected in NS-SV-DC cells after treatment with 5-Aza-CdR. By analyzing the luciferase activity of transfected AQP5 promoter vectors, it became evident that demethylation at the CGs cooperatively functions between these two sites to induce AQP5 expression. Our data, therefore, suggest that treatment of ductal cells with 5-Aza-CdR could result in the expression of the AQP5 gene, thereby leading to increased fluid secretion from ductal cells in SS salivary glands.     

Plateau–patella angle: An option for the evaluation of patellar height in patients with patellar instability

Background

Patellar instability is a debilitating disease. An important factor related to recurrent dislocation is patellar height. A new method of patellar height measurement, the plateau–patella angle (PPA), was proposed in 2011. However, to date, there is no study evaluating the use of this method in patients with patellar instability. The aim of this study was to evaluate the PPA in patients with recurrent patellar dislocation.

Expression of angiotensinogen and receptors for angiotensin and prorenin in the monkey and human substantia nigra: an intracellular renin–angiotensin system in the nigra

We have previously obtained in rodents a considerable amount of data suggesting a major role for the brain renin–angiotensin system (RAS) in dopaminergic neuron degeneration and potentially in Parkinson’s disease. However, the presence of a local RAS has not been demonstrated in the monkey or the human substantia nigra compacta (SNc). The present study demonstrates the presence of major RAS components in dopaminergic neurons, astrocytes and microglia in both the monkey and the human SNc. Angiotensin type 1 and 2 and renin–prorenin receptors were located at the surface of dopaminergic neurons and glial cells, as expected for a tissular RAS. However, angiotensinogen and receptors for angiotensin and renin–prorenin were also observed at the cytoplasm and nuclear level, which suggests the presence of an intracrine or intracellular RAS in monkey and human SNc. Although astrocytes and microglia were labeled for angiotensin and prorenin receptors in the normal SNc, most glial cells appeared less immunoreactive than the dopaminergic neurons. However, our previous studies in rodent models of PD and studies in other animal models of brain diseases suggest that the RAS activity is significantly upregulated in glial cells in pathological conditions. The present results together with our previous findings in rodents suggest a major role for the nigral RAS in the normal functioning of the dopaminergic neurons, and in the progression of the dopaminergic degeneration.     

Evolution of drug-resistant mutations in HBV genomes in patients with treatment failure during the past seven years (2010–2016)

The objective of this study was to analyze the prevalence of drug-resistant HBV mutants in patients with treatment failure during the past seven years (2010–2016). 4055 HBV-infected patients who underwent HBV polymerase gene mutation test from 2010 to 2016 were enrolled. The nucleos(t)ide analogues (NAs) resistance mutation positions, including rtL180, rtA181, rtT184, rtS202, rtM204, rtI233, rtN236, rtI169, rtV173, and rtM250 were analyzed. Genotypic resistance mutations were detected in 30.8% (1248/4055) of the patients with treatment failure. Rates of drug-resistant mutations associated with LAM, ADV, ETV, and multidrug were 27.23% (1104/4055), 9.67% (392/4055), 3.69% (150/4055), and 0.79% (32/4055). Among the primary NA-resistant mutations, rtM204I (13.44%, 545/4055) occurred more frequently, followed by rtM204V, rtN236T, rtA181T, and rtA181V. For single-base mutations, rtL180M and rtA181V increased gradually during the past seven years, while rtM204I/V and rtN236T decreased after 2015. The development of drug-resistant mutations positively correlated with the consumption of ETV (r = 0.964, P = 0.002), and weakly correlated with that of LAM (r = 0.679, P = 0.109) and ADV (r = 0.429, P = 0.354). Moreover, single-base mutation rtA181V and multi-base mutations (rtL180M + M204I and rtL180M + M204V + M204I) were more common in HBV genotype C than those in genotype B (1.94% vs. 0.66%, 1.84% vs. 0.16%, 1.02% vs. 0.16%, respectively). NA-related mutations in HBV RT region increased in the past seven years, especially for LAM. Frequencies of rtL180M and rtA181T/V increased gradually in the past seven years, to which we should pay more attention.     

Long-term trends in the epidemiology of human leptospirosis (Slovak Republic, 1954–2006)

The purpose of this study was the observation of eventual shifts in some basic epidemiological features of human leptospirosis in Slovakia over a long period of time. Epidemiological traits of human leptospirosis were evaluated in three decades: 1954-1963 (822 cases), 1976-1985 (477 cases) and 1997-2006 (310 cases). The evaluation encompassed the aetiologic structure of cases, the incidence rate of diseases, men-to-women ratio of patients, as well as the professional and seasonal distribution of patients. The most affected feature was the incidence rate, which decreased by more than 70% over time. Another considerable change was the proportion of different major serological types of leptospirosis. The initially prevailing Sejroe infections fell to 4th place in the percentage rank, while Grippotyphosa disease, which was ranked 2nd place at the beginning of the observations, became dominating. Icterohaemorrhagiae disease climbed from 4th place to 2nd place. Third place was reserved by the Pomona?+?Tarassovi infections during the whole study period. A distinct tendency of age- and gender-specific incidence rate compared to the proportion of leptospirosis by age and gender was noticed; only minor alterations of the values of both parameters were registered over time. The overall value of the men-to-women ratio (MWR) of diseased persons was virtually within the same range in all three time periods but varied according to different age groups. The MWRs relative to the causal Leptospira serovars were stable over time but markedly differed among distinct serovars. Incidence rates related to age and aetiology showed different trends for the major serological types of leptospirosis. Changes were observed in the professional distribution of leptospirosis: there was an important proportional decrease of cases among farmers and field workers, an increase among house-wives?+?pensioners, but only some slight changes in abattoir workers/butchers, pupils?+?students and workers. The seasonal distribution of patients did not show any remarkable changes; the maximum percentage of cases occurred during the period extending from July to November during the whole period of observation. The epidemiological features of human leptospirosis underwent important shifts in the Slovak Republic over a 50-year period of time. They were very closely related to economical, social and political changes, which are discussed in this paper. The results may be useful for specialists in other European countries.     

Evaluation of a standardised real-time PCR based DNA-detection method (Realstar®) in whole blood for the diagnosis of primary human cytomegalovirus (CMV) infections in immunocompetent patients

Cytomegalovirus (CMV) DNA detection in blood could, as a supplementary test to serology, improve the accuracy and speed of diagnosis of an acute CMV infection. In this study we evaluated the performance of a commercially available and standardised CMV PCR assay in whole blood for the diagnosis of a primary infection in immunocompetent adults. Moreover, the kinetics of viral DNA was evaluated in order to provide a time frame in which viral DNA could be detected during an acute primary infection. Whole blood samples were collected from 66 patients with an acute CMV infection, 65 patients with an acute Epstein-Barr virus infection, 27 patients with various other acute infections (parvovirus B19, HIV, Toxoplasma gondii), 20 patients with past CMV infections (>1 year) and 20 apparently healthy persons. For CMV DNA detection and quantification a commercially available real-time PCR was applied (RealStar®, altona Diagnostics). The clinical sensitivity of CMV PCR in whole blood for the diagnosis of a recent primary CMV infection was 93.9 % and the diagnostic specificity 99.2 %. In the majority of the patients CMV DNA was not detectable anymore approximately within 4 weeks after the first blood sample was taken. From these data we concluded that, together with a suggestive serological profile, a positive CMV PCR result in whole blood can be regarded as a diagnostic confirmation of a recent CMV infection on a single blood sample in an immunocompetent patient. However, a negative CMV PCR result does not exclude a recent CMV infection.     

Is the human papillomavirus test in combination with the Papanicolaou test useful for management of patients with diagnoses of atypical squamous cells of undetermined significance/low-grade squamous intraepithelial lesions?

OBJECTIVE: To determine whether human papillomavirus (HPV) testing is useful in the evaluation of patients diagnosed with atypical squamous cells of undetermined significance (ASCUS)/low-grade squamous intraepithelial lesion (LSIL) and whether the HPV test is appropriate as an alternative screening method. DESIGN: The results of Papanicolaou (Pap) tests and subsequent hybrid capture tube (HCT) II tests for high-risk-type HPV were analyzed for 457 patients. Among these tests, 208 histologic diagnoses were made and correlated with the results of Pap and HPV tests. The sensitivity and specificity of the Pap test, HPV test, and the combined method of Pap and HPV tests to detect cervical intraepithelial neoplasia (CIN) 2/3 and all CIN were also measured. RESULTS: Sixty (63.8%) of 94 women with LSIL and 31 (26.3%) of 118 women with ASCUS tested positive for high-risk HPV. The sensitivity values for Pap tests in detecting all cases of CIN and CIN 2/3 were 91.4% and 92.9%, respectively. The sensitivity values of HCT II tests using the high-risk probe for detecting all cases of CIN and CIN 2/3 were 62.6% and 88.1%, respectively. Biopsies confirmed that 10 (22.7%) of 44 LSIL patients with high-risk HPV had CIN 2/3, but only 1 (4.5%) of 22 LSIL patients without high-risk HPV had CIN 2/3. CONCLUSION: Testing for high-risk HPV with the HCT II test is useful in the detection of CIN 2/3 in LSIL groups and in the selection of patients for colposcopy in ASCUS groups, but it is not suitable for cervical cancer screening tests.