High Serum IgG4 Levels Research Articles

The immune responses elicited by six recombinant antigens of Mycoplasma hyopneumoniae in mice

Mycoplasma hyopneumoniae (M. hyopneumoniae) is the causative agent of swine enzootic pneumonia, resulting in substantial economic losses in global pig farming. Although vaccination is the primary strategy for controlling M. hyopneumoniae infection, current vaccines fall short in preventing transmission of this pathogen or protecting the body from secondary infection. This study aimed to assess the immunogenicity of six recombinant antigens (P97R1, P46, GAPDH, PdhA, DnaK, and EF-Tu) of M. hyopneumoniae through intramuscular immunization in mice. The results showed that the six antigens elicited high levels of serum IgG. Among them, P97R1, P46, PdhA, and DnaK stimulated robust antigen-specific IgA mucosal immune responses. CCK-8 assays revealed that both P97R1 and DnaK significantly increased the proliferation of mononuclear cells from spleen and lung, and DnaK also promoted the proliferation of blood mononuclear cells. Additionally, PdhA induced Th17-type immune response with a high level of IL-17 level in serum. Flow cytometry analysis indicated that P97R1 and PdhA increased the ratio of CD8+/CD4+ T lymphocyte, favoring cytotoxic T lymphocyte (CTL) immune responses. Notably, P97R1 immunization significantly decreased the percentages of CD4+ T cells while increased the percentages of CD8+ T cells. The present findings demonstrate that the candidate antigens P97R1, PdhA, and DnaK of M. hyopneumoniae induce specific humoral and mucosal immunity; P97R1 and DnaK also stimulated intense cellular immunity, and PdhA induced CTL and Th17-type immune responses. In conclusion, P97R1, PdhA, and DnaK emerge as potential candidate antigens for the future development of a more effective subunit vaccine against M. hyopneumoniae.

IgG4 Sclerosing Cholangitis: Entity Rarely Described in Children

IgG4-related sclerosing cholangitis (IgG4-SC) is known in the adult patients as a steroid-responsive biliary disease, frequently associated with autoimmune pancreatitis; The diagnosis of IgG4-SC may be difficult to differentiate from primary sclerosing cholangitis (PSC) or cholangiocarcinoma; This entity is been described in the absence of pancreatic implication. It is defined by high level of serum IgG4 in contrast to primary sclerosing cholangitis. It’is morphologically characterized by dense lymphoplasmacellular infiltration, particularly IgG4+ plasma cells and CD4+ T cells and extensive fibrosis in bile duct. In patients with IgG4-related sclerosing cholangitis, response to steroid therapy is high; in patients with PSC corticosteroid therapy is unsuccessful. An Early recognition of IgG4-SC can save patients from potential harmful and unnecessary surgical interventions. In the literature, cholangiocarcinoma in patients with IgG4- related sclerosing cholangitis was not described, whereas cholangiocarcinoma develops in up to 10-30% of patients with PSC. We present the case of a 3 years old child with features of sclerosing IgG4 cholangitis with asymptomatic elevation in liver enzymes, bile duct strictures on imaging, characteristic pathology findings, elevated serum IgG4, without signs of pancreatic involvement, and excellent response to corticosteroids. Pediatric gastroenterologists and hepatologists, as well as pediatric hepatopathologists, need to be aware of IgG4-SC as a disease entity.

Only repeatedly elevated IgG4 levels in primary sclerosing cholangitis may distinguish a particular patient phenotype

BackgroundPrimary sclerosing cholangitis (PSC) is a chronic liver disease leading to inflammation with scaring and strictures of bile ducts, which can lead to liver cirrhosis. A subtype of PSC characterized by high serum IgG4 (sIgG4) levels has been reported to be associated with poor outcomes, but the exact role and the longitudinal development of sIgG4 levels in PSC progression remains to be clarified. The aim of this study was to investigate if subsequent analysis of sIgG4 levels allows the identification of the PSC phenotype with high sIgG4.MethodssIgG4 values were repeatedly analysed in a well-characterized European PSC cohort of 110 individuals. Biochemical parameters, clinical endpoints, death and liver transplantation were compared between PSC subgroups.Results12.7% (n = 14) of PSC patients showed increased sIgG4 levels (PSC-IgG4). The values normalized in 57.1% (n = 8; PSC-IgG4norm) during follow-up measurements, whereas the values remained permanently elevated in 42.9% (n = 6; PSC-IgG4const). Serum values of AP and γGT were significantly higher in PSC-IgG4const compared to PSC-IgG4norm at final blood sampling. Furthermore, mean age at PSC diagnosis was markedly lower in PSC-IgG4const compared to PSC-IgG4norm.ConclusionsThis is the first study analyzing longitudinal development of sIgG4 in PSC. Our data indicate that only sequential determination of sIgG4 levels allow to accurately distinguish between the PSC phenotype with high sIgG4 and PSC with low sIgG4.Graphical abstract

Crohn’s patients and healthy infants share immunodominant B cell response to commensal flagellin peptide epitopes

Inflammatory bowel disease (IBD) is a chronic manifestation of dysregulated immune response to the gut microbiota in genetically predisposed hosts. Nearly half of patients with Crohn's disease (CD) develop selective serum immunoglobulin (Ig)G response to flagellin proteins expressed by bacteria in the Lachnospiraceae family. This study aimed to identify the binding epitopes of these IgG antibodies and assess their relevance in CD and in homeostasis. Sera from an adult CD cohort, a treatment-naïve pediatric CD cohort, and 3 independent non-IBD infant cohorts were analyzed using novel techniques including a flagellin peptide microarray and a flagellin peptide cytometric bead array. A dominant B cell peptide epitope in patients with CD was identified, located in the highly conserved "hinge region" between the D0 and D1 domains at the amino-terminus of Lachnospiraceae flagellins. Elevated serum IgG reactivity to the hinge peptide was strongly associated with incidence of CD and the development of disease complications in children with CD up to 5 years in advance. Notably, high levels of serum IgG to the hinge epitope were also found in most infants from 3 different geographic regions (Uganda, Sweden, and the United States) at 1 year of age, which decrements rapidly afterward. These findings identified a distinct subset of patients with CD, united by a shared reactivity to a dominant commensal bacterial flagellin epitope, that may represent failure of a homeostatic response to the gut microbiota beginning in infancy.

The impact of vaccine type and booster dose on the magnitude and breadth of SARS-CoV-2-specific systemic and mucosal antibodies among COVID-19 vaccine recipients

The COVID-19 pandemic has had a major impact on global health and economy, which was significantly mitigated by the availability of COVID-19 vaccines. The levels of systemic and mucosal antibodies against SARS-CoV-2 correlated with protection. However, there is limited data on how vaccine type and booster doses affect mucosal antibody response, and how the breadth of mucosal and systemic antibodies compares. In this cross-sectional study, we compared the magnitude and breadth of mucosal and systemic antibodies in 108 individuals who received either the BNT162b2 (Pfizer) or CoronaVac (SinoVac) vaccine. We found that BNT162b2 (vs CoronaVac) or booster doses (vs two doses) were significantly associated with higher serum IgG levels, but were not significantly associated with salivary IgA levels, regardless of prior infection status. Among non-infected individuals, serum IgG, serum IgA and salivary IgG levels were significantly higher against the ancestral strain than the Omicron BA.2 sublineage, but salivary IgA levels did not differ between the strains. Salivary IgA had the weakest correlation with serum IgG (r = 0.34) compared with salivary IgG (r = 0.63) and serum IgA (r = 0.60). Our findings suggest that intramuscular COVID-19 vaccines elicit a distinct mucosal IgA response that differs from the systemic IgG response. As mucosal IgA independently correlates with protection, vaccine trials should include mucosal IgA as an outcome measure.

Surface Display of Duck Hepatitis A Virus Type 1 VP1 Protein on Bacillus subtilis Spores Elicits Specific Systemic and Mucosal Immune Responses on Mice.

Duck viral hepatitis, primarily caused by duck hepatitis A virus type 1 (DHAV-1), poses a significant threat to the global duck industry. Bacillus subtilis is commonly utilized as a safe probiotic in the development of mucosal vaccines. In this study, a recombinant strain of B. subtilis, designated as B. subtilis RV, was constructed to display the DHAV-1 capsid protein VP1 on its spore surface using the outer coat protein B as an anchoring agent. The immunogenicity of this recombinant strain was evaluated in a mouse model through mixed feeding immunization. The results indicated that B. subtilis RV could elicit specific systemic and mucosal immune responses in mice, as evidenced by the high levels of serum IgG, intestinal secretory IgA, and potent virus-neutralizing antibodies produced. Furthermore, the recombinant strain significantly upregulated the expression levels of IL-2, IL-6, IL-10, TNF-α, and IFN-γ in the intestinal mucosa. Thus, the recombinant strain maintained the balance of the Th1/Th2 immune response and demonstrated an excellent mucosal immune adjuvant function. In summary, this study suggests that B. subtilis RV can be a novel alternative for effectively controlling DHAV-1 infection as a vaccine-based feed additive.

Identification of relapse predictors of IgG<sub>4</sub>-related sclerosing cholangitis

Introduction. Relapses occur in 30–50% of patients IgG4-related sclerosing cholangitis. Relapses may act an independent risk factor for malignancy development and the need in maintenance therapy for relapse prevention is still uncertain. Thus, studying relapse predictors and developing reliable preventive approaches is an important area of research for this condition.Aim. To determine relapse predictors of IgG4-related sclerosing cholangitis.Materials and methods. A single- center dynamic bidirectional observational study was conducted in patients aged 18 years and older with verified IgG4-related sclerosing cholangitis (n = 32). We searched for possible factors influencing the relapse of IgG4- related sclerosing cholangitis. The development of a prognostic model for the relapse probability was carried out using logistic regression. ROC analysis was used to assess the diagnostic performance of quantitative variables in predicting of relapse.Results. The median follow-up period was 33 (16–60) months. The majority of patients with IgG4-related sclerosing cholan- gitis were male (71.9%), median age was 59 ± 13 years. In most patients, delayed diagnosis (median 10.5 [4.8; 22.5] months) was associated with overdiagnosis of primary sclerosing cholangitis (41.2%) or bile duct malignancy (43.8%). Surgical interventions were performed in 50% of patients. Median serum IgG4 level was 2.70 g/L [1.92; 6.48], and 21.9% of patients had normal serum IgG4 level. Disease relapse developed in 34.4% (n = 11) of patients. Serum IgG4 level before glucocorticosteroid therapy ≥ 2.24 g/L and a delay in diagnosis by ≥ 17 months were associated with the relapse (p = 0.040 and p = 0.049 respectively). Multi-organ involvement, and extrahepatic localization of biliary strictures in the patients with the history of surgical interventions increased the risk of relapse 85 (p = 0.001) and 12 (p = 0.047) fold, respectively. The presence of biliary strictures below the confluence reduced the risk of relapse 7.5 fold (p = 0.032).Conclusions. Possible predictors of IgG4-related sclerosing cholangitis relapse may include multi- organ involvement, intrahepatic and proximal extrahepatic strictures, prior surgical interventions in patients with extrahepatic strictures, high serum IgG4 level, and delayed diagnosis.

Common Characteristics of Sinonasal Inflammation Associated with IgG4-Related Disease and Other Chronic Inflammatory Diseases: A Retrospective Observational Study

Plain Language SummaryImmunoglobulin G4-related disease (IgG4-RD) is a systemic inflammatory disease characterized by elevated serum IgG4 levels and tissue IgG4-positive cells. A part of IgG4-RD patients has sinonasal lesions. Because other inflammatory diseases also have features common to IgG4-RD, accurate knowledge of IgG4-RD is required. However, very little is known about IgG4-related rhinosinusitis. This study retrospectively analyzed clinicopathological features of IgG4-related rhinosinusitis and compared IgG4-related rhinosinusitis with other inflammatory diseases. Seven patients with sinonasal lesions and high serum IgG4 levels were retrospectively reviewed. Six of 7 patients were diagnosed with IgG4-RD, while one was diagnosed with granulomatosis with polyangiitis (GPA). In the 6 patients with IgG4-RD, intranasal findings showed nasal polyps in 3 patients (50%) and computed tomography showed ethmoid sinus involvement in 5 patients (83%), which shared common features with eosinophilic sinusitis (ECRS). However, no patients showed histopathological eosinophil infiltration. Although the patient with GPA revealed tissue infiltration of IgG4-positive cells in the nasal biopsy, the patient also had saddle nose and positivity of myeloperoxidase-antineutrophil cytoplasmic antibody (ANCA), which indicated GPA. We diagnosed the patient with GPA, which is a known mimicker of IgG4-RD. In this study, the patients with IgG4-related rhinosinusitis had clinical and pathological characteristics similar to those of ECRS and GPA. IgG4-related rhinosinusitis should be diagnosed based on not only tissue infiltration of IgG4-positive cells but also systemic findings including nasal findings and serum ANCA levels. IgG4-RD should be ruled out in patients with eosinophilia without histopathological eosinophil infiltration.

Essential role of local antibody distribution in mediating bone-resorbing effects

The link between antibodies and bone mass is debated. Activated IgG, which interacts directly with Fc gamma receptors, stimulates osteoclastogenesis in vitro, and local injection in immune-activated mice leads to bone loss. Multiple myeloma patients with high serum IgG levels have induced osteoclast activation and display bone loss. In addition, bone loss has been linked to serum autoantibodies in autoimmune diseases, including anti-citrullinated protein antibodies (ACPA) in individuals with rheumatoid arthritis (RA). Whether serum IgG or autoantibodies regulate bone mass under healthy conditions is poorly studied. In elderly men, neither serum levels of polyclonal IgG nor autoantibody were associated with areal bone mineral density in the MrOS Sweden study. Repetitive systemic injections of high-dose polyclonal IgG complexes in mice did not exert any discernible impact on bone mineral density. However, repetitive local intra-articular injection of the same IgG complexes led to a localized reduction of trabecular bone density. These results indicate antibodies may only impact bone density when close to the bone, such as within the synovial joint.

Diagnostic challenges of the idiopathic plasmacytic lymphadenopathy (IPL) subtype of idiopathic multicentric Castleman disease (iMCD): Factors to differentiate from IgG4-related disease

Aims and methodsIdiopathic multicentric Castleman disease (iMCD) is currently considered to be classified into three clinical subtypes, including idiopathic plasmacytic lymphadenopathy (IPL), thrombocytopaenia, anasarca, fever, reticulin fibrosis/renal dysfunction, organomegaly (TAFRO)...

An overlapping case of IgG4-related disease and systemic lupus erythematosus treated with belimumab: a case-based review.

IgG4-related disease (IgG4-RD) is a systemic condition in which IgG4+ plasma cell infiltration and fibrosis cause organ swelling and lead to diverse clinical manifestations. Although IgG4-RD typically responds to glucocorticoids (GCs), relapse during tapering occurs and an early GC-sparing approach might therefore be beneficial. Systemic lupus erythematosus (SLE) is a chronic inflammatory disease with multiple symptoms that is also treated with GCs as a first-line therapy. Recently, belimumab, a recombinant human IgG-1λ monoclonal antibody that inhibits B-cell activating factor, was approved, but reports of use for IgG4-RD are scarce. Here, we present a rare case of IgG4-RD complicated with SLE which was successfully treated with belimumab. A 67-year-old man was diagnosed with IgG4-RD based on a high serum IgG4 level and histopathological findings. Furthermore, he had pericardial effusion on echocardiography, and laboratory tests revealed thrombocytopenia, autoimmune hemolysis, positive anti-nuclear antibodies, positive anti-DNA antibodies, and hypocomplementemia. These data led to an SLE diagnosis. Treatment was started with prednisolone at 40mg/day, plus hydroxychloroquine, which initially improved both the SLE and IgG4-RD symptoms. During the GC tapering, belimumab was added and clinical symptoms resolved completely. Our case and the literature review summarize reported rare overlapping cases of IgG4-RD and SLE and suggest that belimumab is a promising candidate for the treatment of IgG4-RD.

Effect of a Multi-Strain Probiotic on Growth Performance, Lipid Panel, Antioxidant Profile, and Immune Response in Andaman Local Piglets at Weaning

This study aimed to investigate the role of a multi-strain probiotic compound containing Bacillus mesentericus, Bacillus coagulans, Enterococcus faecalis, and Clostridium butyricum as an in-feed zinc oxide (ZnO) alternative in growth performance, diarrhea incidence, antioxidant profile, lipid panel, stress, and immunity in piglets at weaning. Seventy-two piglets weaned at 27 ± 1 day were divided randomly into three groups with four replicates of six piglets each: (i) a negative control group (WC) fed only a basal diet, (ii) a probiotic group (WB) fed a basal diet with the current probiotic formulation, and (iii) a positive control (PC) group fed a basal diet with 2500 mg/kg ZnO. The experiment was conducted for 28 days. Probiotic supplementation showed a positive effect on growth performance and reduced the diarrhea rate. The mean body weight of the piglets in the WB and PC groups was significantly higher than that of piglets in the WC group (14.88 ± 0.12, 14.97 ± 0.13 vs. 13.80 ± 0.06 kg; p ≤ 0.001). The addition of probiotic to the diet improved the lipid panel; the WB group showed a significantly higher level of high-density lipoprotein cholesterol (mg/dL) (32.67 ± 0.85 in WB vs. 12.48 ± 0.76 in WC; p ≤ 0.001) and lower levels of total cholesterol (mg/dL) (59.78 ± 1.97 in WB vs. 119.11 ± 2.12 in WC; p ≤ 0.001) and low-density lipoprotein cholesterol (mg/dL) (17.90 ± 1.12 in WB vs. 69.10 ± 3.37 in WC; p ≤ 0.001) compared with the negative control group. Moreover, probiotic supplementation enhanced the antioxidant defense system and provided protection from oxidative damage by increasing the concentrations of serum catalase, glutathione-S-transferase, and superoxide dismutase and by decreasing the concentrations of serum malonyldialdehyde and total nitric oxide. Heat shock proteins and other stress markers, such as serum cortisol, were reduced in the probiotic-fed group. The probiotic group also displayed higher levels of serum IgG and IgM at all time points and higher IgA on day 28 compared with the negative control group. Altogether, these results indicate that feeding with the currently used multi-strain probiotic formulation minimizes weaning stress, thereby improving the growth performance, antioxidant profile, lipid panel, and systemic and mucosal immunity. Therefore, multi-strain probiotic compounds may be used to replace ZnO in weaned piglets.

A case of IgG4-related hypophysitis maintained remission of diabetes insipidus for over 3 months after completion of steroid treatment.

IgG4-related disease is a multiorgan disorder in which nodules and hypertrophic lesions are observed simultaneously, or separately, in areas including the pancreas, liver, lungs, salivary glands, thyroid glands, and pituitary glands. IgG4-related hypophysis is one of several IgG4-related diseases and is characterized by pituitary gland and pituitary stalk thickening, various degrees of hypopituitarism, and increased serum IgG4 levels. Steroid therapy is effective for patients with IgG4-related hypophysis, but the reported effectiveness of steroid therapy for restoring pituitary function differs between studies. Following an episode of autoimmune pancreatitis 10 years prior, enlargement of the pituitary gland and stalk along with panhypopituitarism and polyuria developed in a 73-year-old male. A high serum IgG4 level and biopsy of the submandibular gland showing infiltration of IgG4-positive plasma cells led to a clinical diagnosis of IgG4-related hypophysitis. Prednisolone treatment reduced the swelling of the pituitary gland and stalk and improved anterior pituitary function. Although arginine vasopressin secretion remained insufficient, polyuria was relieved and kept in remission even after prednisolone treatment was completed. This is the first reported case in which prednisolone was able to maintain both normal anterior pituitary function and remission of polyuria caused by IgG4-related hypophysitis. IgG4-related hypophysitis has previously been associated with a relapse of symptoms during treatment. However, the patient reported in this case study remained in remission for over 3 months after completion of steroid treatment and should be monitored closely for changes in pituitary function. Steroid therapy is the first-line therapy for pituitary dysfunction and pituitary stalk swelling in IgG4-related hypophysitis. In this case, although posterior pituitary function remained insufficient, polyuria was relieved and kept in remission for over 3 months even after prednisolone treatment was completed. IgG4-related hypophysitis has been associated with the relapse of symptoms during steroid tapering, and changes in pituitary function and symptoms should be monitored closely. When we encounter cases of adrenal insufficiency and polyuria during observation of autoimmune pancreatitis or other IgG4-related disease, we should consider the possibility of IgG4-related hypophysitis in mind.

Clinical significance of the detection of serum IgG4 and IgG4/IgG ratio in patients with thyroid-associated ophthalmopathy.

To evaluate the clinical significance of detecting serum IgG4 and the IgG4/IgG ratio in patients with thyroid-associated ophthalmopathy (TAO) and to explore whether high serum IgG4 levels and the IgG4/IgG ratio are associated with the severity and activity of TAO, we retrospectively assessed the records of 78 TAO patients and 32 controls collected in our hospital from July 2020 to July 2022. The TAO patients were divided into TAO inactive and TAO active phase groups according to the clinical activity score (CAS), and we evaluated the association between the serum IgG4 levels, the IgG4/IgG ratio, and the clinical data of the participants. The levels of IgG4 significantly increased in the TAO active group compared to those in the inactive and control groups (P < 0.05). Additionally, the number of patients with increased IgG4 levels (≥135 mg/dL) in the TAO active group was markedly higher than that in the inactive and control groups (P < 0.05). The IgG4/IgG ratio was also significantly enhanced in the TAO active group compared to the inactive and control groups (P < 0.05). CAS was identified as an independent factor influencing IgG4 levels in patients with TAO. The levels of serum IgG4, as well as the IgG4/IgG ratio, were significantly increased in some patients with active TAO, and they were related to the CAS, suggesting that the pathogenesis of TAO may be heterogeneous.

Unraveling the transcriptome-based network of tfh cells in primary sjogren syndrome: insights from a systems biology approach.

Primary Sjogren Syndrome (pSS) is an autoimmune disease characterized by immune cell infiltration. While the presence of follicular T helper (Tfh) cells in the glandular microenvironment has been observed, their biological functions and clinical significance remain poorly understood. We enrolled a total of 106 patients with pSS and 46 patients without pSS for this study. Clinical data and labial salivary gland (LSG) biopsies were collected from all participants. Histological staining was performed to assess the distribution of Tfh cells and B cells. Transcriptome analysis using RNA-sequencing (RNA-seq) was conducted on 56 patients with pSS and 26 patients without pSS to uncover the underlying molecular mechanisms of Tfh cells. To categorize patients, we employed the single-sample gene set enrichment analysis (ssGSEA) algorithm, dividing them into low- and high-Tfh groups. We then utilized gene set enrichment analysis (GSEA), weighted gene co-expression network analysis (WGCNA), and deconvolution tools to explore functional and immune infiltration differences between the low- and high-Tfh groups. Patients with pSS had a higher positive rate of the antinuclear antibody (ANA), anti-Ro52, anti-SSA, anti-SSB and hypergammaglobulinaemia and higher levels of serum IgG compared to the non-pSS. Histopathologic analyses revealed the presence of Tfh cells (CD4+CXCR5+ICOS+) in germinal centers (GC) within the labial glands of pSS patients. GSEA, WGCNA, and correlation analysis indicated that the high-Tfh group was associated with an immune response related to virus-mediated IFN response and metabolic processes, primarily characterized by hypoxia, elevated glycolysis, and oxidative phosphorylation levels. In pSS, most immune cell types exhibited significantly higher infiltration levels in the high-Tfh group compared to the low-Tfh group. Additionally, patients in the Tfh-high group demonstrated a higher positive rate of the ANA, rheumatoid factor (RF), and hypergammaglobulinaemia, as well as higher serum IgG levels. Our study suggests that Tfh cells may play a crucial role in the pathogenesis of pSS and could serve as potential therapeutic targets in pSS patients.

Two Cases of Acquired High-Density Lipoprotein Deficiency with Immunoglobulin G4-Related Lecithin-Cholesterol Acyltransferase Autoantibody.

Lecithin-cholesterol acyltransferase (LCAT) plays a significant role in the progression from premature to mature high-density lipoprotein (HDL) in circulation. Consequently, primary or secondary LCAT deletion or reduction naturally results in low serum HDL cholesterol levels. Recently, rare cases of acquired HDL deficiency with LCAT autoantibodies have been reported, mainly from Japan, where LCAT autoantibodies of immunoglobulin G (IgG) caused the HDL deficiency. Here to our knowledge, we report for the first time two cases of acquired HDL deficiency caused by IgG4 linked LCAT autoantibodies with or without a high serum IgG4 level. Furthermore, these cases can extend to a new concept of "IgG4 autoimmune disease" from the viewpoint of verifying the serum autoantibody and/or renal histopathology.

Adjuvanted quaternized chitosan composite aluminum nanoparticles-based vaccine formulation promotes immune responses in chickens.

Aluminum adjuvant is a typical adjuvant that can promote humoral immune response, but it lacks the ability to effectively induce cellular immune response. The water-soluble N-2-Hydroxypropyl trimethyl ammonium chloride chitosan nanoparticles (N-2-HACC NPs) can enhance humoral and cellular immune responses of vaccines. To enable aluminum adjuvant to induce cellular immunity, the composite nano adjuvant N-2-HACC-Al NPs were synthesized by the N-2-HACC and aluminum sulfate (Al2(SO4)3). The particle size and zeta potential of the N-2-HACC-Al NPs were 300.70±24.90nm and 32.28±0.52mV, respectively. The N-2-HACC-Al NPs have good thermal stability and biodegradability and lower cytotoxicity. In addition, to investigate the immunogenicity of the composite nano adjuvant, the combined inactivated vaccine against Newcastle disease (ND) and H9N2 avian influenza (AI) was prepared with the N-2-HACC-Al NPs as a vaccine adjuvant. The immune effect of the vaccine (N-2-HACC-Al/NDV-AIV) was evaluated by chicken in vivo immunization. The vaccine induced higher levels of serum IgG, IL-4, and IFN-γ than those of the commercial combined inactivated vaccine against ND and H9N2 AI. The levels of IFN-γ were more than twice those of the commercial vaccine at 7days post the immunization. The N-2-HACC-Al NPs could be used as an efficient nano adjuvant to enhance the effectiveness of vaccine and have immense application potential.

Chronic mucocutaneous candidiasis and immune dysregulation due to STAT1 Gain of Function

BackgroundGermline gain-of-function (GOF) mutations in the Signal Transducer and Activator of Transcription 1 (STAT1) gene have been associated with autosomal dominant chronic mucocutaneous candidiasis (CMCC), autoimmune and inflammatory manifestations. Although most patients with STAT1 GOF have CMCC, the disease has a broad phenotypic spectrum.Case Description: A 13-year-old male born to non-consanguineous parents with a past medical history of chronic mucocutaneous candidiasis, autoimmune hypothyroidism, and recurrent viral respiratory tract infections presented for immune evaluation. His medical history was also significant for chronic fatigue refractory to thyroid replacement therapy, chronic paronychia, oral thrush, pneumonia requiring hospitalization, recurrent chalazia status post excision, and prolonged tonsillitis. Laboratory results showed high total serum IgG levels with elevated IgG1 and IgG3 subclasses, elevated B cell counts with atypical lymphocytes, and chronic EBV-viremia. He had no clinical or laboratory evidence of active lymphoproliferative disease. He had normal lymphocyte proliferation to mitogens with impaired response to antigens. He had an adequate humoral response to protein and polysaccharide antigens. Targeted genetic testing for inborn errors of immunity showed a heterozygous variant in the STAT1 gene (c.1169T>C, p.MET390Thr), which had been previously reported in patients with STAT1 GOF. The patient was treated with oral fluconazole with interval improvement in CMCC and subsequently maintained on prophylactic fluconazole and TMP/SMX. He had an unremarkable family history, which suggests a de novo mutation in STAT1. ConclusionThe presence of CMCC and autoimmunity should raise concern for STAT1 GOF. Genetic testing for inborn errors of immunity can be a valuable tool in the diagnosis of patients with CMCC and can help guide therapy. Unfortunately, hematopoietic stem cell transplant has been associated with a high mortality rate in patients with STAT1 GOF. JAK inhibition therapy was recommended for this patient. However, there is currently no consensus regarding JAK inhibitor selection, dosing, treatment duration or biomarkers in STAT1 GOF.

Design of a chimeric protein composed of FimH, FyuA and CNF-1 virulence factors from uropathogenic Escherichia coli and evaluation its biological activity and immunogenicity in vitro and in vivo.

Urinary tract infections (UTIs) caused by Uropathogenic Escherichia coli (UPEC) are among the most prevalent bacterial infections in humans. Antibiotic resistance among UPEC isolates is increasing, and designing an effective vaccine can prevent or reduce these infections. FimH adhesin, iron scavenger receptor FyuA, and cytotoxic necrotizing factor -1 (CNF-1) are among the most important virulence factors of UPEC strains. Thus, a novel multi-epitope protein composed of FimH, FyuA, and CNF-1 was designed to evaluate its biological activity and immunogenicity in vitro and in vivo, respectively. The final vaccine design had seven domains, including the N-terminal domain of FimH, four domains of FyuA, and two domains of CNF-1, as determined by immunoinformatics analysis. The results of tertiary structure prediction showed that the chimeric protein had a C-score of -0.25 and Z-score of -1.94. Molecular docking indicated that thirty six ligand residues of the chimeric protein interacted with 53 receptor residues of TLR-4 by hydrogen bonds and hydrophobic interactions. Analysis of protein expression by SDS-PAGE showed an approximately 44kDa band with different concentrations of IPTG which were confirmed by Western blot. According to ELISA results, the level of IL-8 produced by stimulated Ht29cells with the chimeric protein was significantly higher than the stimulated Ht29cells with CNF-1 alone and un-stimulated Ht29cells. Rabbits subcutaneously immunized with the chimeric protein admixed with Freund adjuvant induced higher level of serum IgG on day 14 after the first vaccination than control rabbits. Furthermore, the booster dose of the chimeric protein significantly enhanced the IgG levels as compared to day 14 and also controls. As, the chimeric protein has suitable B-cell epitopes and MHC-I and MHC-II binding epitopes to stimulate humoral and cellular immunity, it could be a promising vaccine candidate against UTIs caused by UPEC. Evaluating the multi-epitope protein in inducing humoral and cellular immune responses, as well as protection, is ongoing in the mice models.

An adult female case of autoimmune pancreatitis with gastric outlet obstruction complicated by annular pancreas.

A 65-year-old woman presented with epigastric pain persisting for more than 3months. She was diagnosed with autoimmune pancreatitis (AIP), based on high serum IgG4 levels (981mg/dL) and diffuse pancreatic enlargement with a capsule-like rim on computed tomography (CT). Additionally, the main pancreatic duct was indistinct on magnetic resonance cholangiopancreatography. CT, esophagogastroduodenoscopy, and upper gastrointestinal radiography revealed stenosis with gastric outlet obstruction (GOO) in the second part of the duodenum. Prednisolone administration was initiated as treatment; on day 3 of treatment, the patient's symptoms improved. After 2weeks, CT and endoscopic ultrasonography of the duodenal bulbs revealed improvement of the enlarged pancreas. The second part of the duodenum ran into the pancreatic head, and no malignant lesions were observed. Based on the above findings, we suspect that she developed AIP in the annular pancreas (AnnP), where duodenal stenosis worsened with diffuse pancreatic enlargement, resulting in GOO. She is currently under careful observation with tapering of prednisolone-without surgical treatment for AnnP. The pathogenesis of GOO caused by AIP without malignancy is rare. One case of GOO caused by AIP, wherein AIP developed in the AnnP (similar to the present case), has been reported, highlighting the novelty of our report.