Serum Antibody Levels Research Articles

Serum interleukin-34 levels in dermatomyositis: a potential biomarker for anti-MDA5-antibody-associated interstitial lung disease.

Interleukin (IL)-34 is a hematopoietic cytokine that promotes macrophage activation. Macrophage activation in interstitial lung disease (ILD) in patients with dermatomyositis (DM), especially in those with anti-melanoma differentiation-associated gene 5 (MDA5) antibody suggests the involvement of IL-34 in the disease. However, the association between IL-34 and DM is unknown. In this study, we aimed to determine serum IL-34 levels in DM patients and evaluate their association with DM-ILD. We measured serum IL-34 levels in 56 DM patients and 14 age- and sex- matched healthy controls by enzyme-linked immunosorbent assay, and examined their correlation with clinical parameters. In addition, pre- and post-treatment serum IL-34 levels were examined using serum samples from 7 anti-MDA5 antibody-positive DM patients. Serum IL-34 levels were significantly elevated in DM patients, especially in those with anti-MDA5 antibody, compared with healthy controls. In anti-MDA5-antibody-positive DM patients, serum IL-34 levels positively correlated with serum levels of ferritin and anti-MDA5 antibody, which are known biomarkers for rapidly progressive (RP)-ILD. Following combined immunosuppressive therapy, serum IL-34 levels decreased along with ferritin and anti-MDA5 antibody. These data suggest that IL-34 may be involved in the development of RP-ILD in anti-MDA5 antibody-positive DM. Serum IL-34 levels can serve as a potential biomarker for RP-ILD in this clinical entity.

Alterations of pathogen transmission patterns and attenuated immune stimulation might be the cause of increased adult respiratory infections cases in 2023, results from a multi-center study in mainland China

BackgroundSeveral respiratory infections outbreaks have been observed in mainland China after reduction of non-pharmaceutical interventions. Other countries have seen increases in respiratory infections outside typical seasons post-COVID-19, warranting investigation into underlying causes. MethodsWe established monitoring networks for suspected respiratory infection in 14 tertiary hospitals nationwide. PCR for SARS-CoV-2, influenza A and B were performed on 3708 respiratory specimens and deep sequencing were conducted to identify co-infections or newly emerging microbes in 2023. Viral evolutionary analysis was completed. We retrospectively detected serum antibody level for various respiratory pathogens from 4324 adults without respiratory infections over 7 years to observe its dynamic curves. FindingsSARS-CoV-2 and influenza A were the main pathogens during outbreaks in 2023, bacterial-virus and bacterial-bacterial co-infections were most detected, but community co-infections didn't significantly increase pneumonia incidence. Different SARS-CoV-2 and influenza variants were present in different outbreaks, and no novel pathogens were found. The epidemiological patterns of influenza A, COVID-19 and etc. were altered, exhibiting characteristics of being "staggered" compared to most global regions, and potentially led to "overlapping prevalence". Binding antibody testing showed regular fluctuation, without significant decrease against common respiratory pathogens in adults. Influenza A antibody stimulation was attenuated during the 2023 outbreak. Conclusions"Misaligned" alteration in seasonal respiratory disease patterns possibly caused combined epidemics, leading to cases spike in China, 2023. In adults, antibody levels didn't show significant decline, but reduced immune response to influenza during 2020–2023 emphasizes the need for consistent vaccination during pandemics.

RBD mutations at the residues K417, E484, N501 reduced immunoreactivity with antisera from vaccinated and COVID-19 recovered patients.

It is unclear whether induced spike protein-specific antibodies due to infections with SARS-CoV-2 or to the prototypic Wuhan isolate-based vaccination can immune-react with the emerging variants of SARS-CoV-2. The main objective of the study was to measure the immunoreactivity of induced antibodies postvaccination with Covishield™ (ChAdOx1 nCoV-19 coronavirus vaccines) or infections with SARS-CoV-2 by using selected peptides of the spike protein of wild type and variants of SARS-CoV-2. Thirty patients who had recovered from SARS-CoV-2 infections and 30 individuals vaccinated with both doses of Covishield™ were recruited for the study. Venous blood samples (5 mL) were collected at a single time point from patients within 3-4 weeks of recovery from SARS-CoV-2 infections or receiving both doses of Covishield™ vaccines. The serum levels of total immunoglobulin were measured in both study groups. A total of 12 peptides of 10 to 24 amino acids length spanning to the receptor-binding domain (RBD) of wild type of SARS-CoV-2 and their variants were synthesized. The serum levels of immune-reactive antibodies were measured using these peptides. The serum levels of total antibodies were found to be significantly (p<0.001) higher in the vaccinated individuals as compared to COVID-19 recovered patients. Our study reported that the mutations in the RBD at the residues K417, E484, and N501 have been associated with reduced immunoreactivity with anti-sera of vaccinated people and COVID-19 recovered patients. The amino acid substitutions at the RBD of SARS-CoV-2 have been associated with a higher potential to escape the humoral immune response.

Mould allergen Alt a 1 spiked with the micronutrient retinoic acid reduces Th2 response and ameliorates Alternaria allergy in BALB/c mice.

We investigated the biological function of the mould allergen Alt a 1 as a carrier of micronutrients, such as the vitamin A metabolite retinoic acid (RA) and the influence of RA binding on its allergenicity invitro and invivo. Alt a 1-RA complex formation was analyzed in silico and invitro. PBMCs from Alternaria-allergic donors were stimulated with Alt a 1 complexed with RA (holo-Alt a 1) or empty apo-Alt a 1 and analyzed for cytokine production and CD marker expression. Serum IgE-binding and crosslinking assays to apo- and holo-protein were correlated to B-cell epitope analysis. Female BALB/c mice already sensitized to Alt a 1 were intranasally treated with apo-Alt a 1, holo-Alt a 1 or RA alone before measuring anaphylactic response, serum antibody levels, splenic cytokines and CD marker expression. In silico docking calculations and invitro assays showed that the extent of RA binding depended on the higher quaternary state of Alt a 1. Holo-Alt a 1 loaded with RA reduced IL-13 released from PBMCs and CD3+CD4+CRTh2 cells. Complexing Alt a 1 to RA masked its IgE B-cell epitopes and reduced its IgE-binding capacity. In a therapeutic mouse model of Alternaria allergy nasal application of holo-Alt a 1, but not of apo-Alt a 1, significantly impeded the anaphylactic response, impaired splenic antigen-presenting cells and induced IL-10 production. Holo-Alt a 1 binding to RA was able to alleviate Th2 immunity invitro, modulate an ongoing Th2 response and prevent anaphylactic symptoms invivo, presenting a novel option for improving allergen-specific immunotherapy in Alternaria allergy.

Alzheimer's disease risk associated with changes in Epstein-Barr virus nuclear antigen 1-specific epitope targeting antibody levels

BackgroundAlzheimer's disease (AD) is a neurodegenerative disorder influenced by age, sex, genetic factors, immune alterations, and infections. Multiple lines of evidence suggest that changes in antibody response are linked to AD pathology. MethodsTo elucidate the mechanisms underlying AD development, we investigated antibodies that target autoimmune epitopes using high-resolution epitope microarrays. Our study compared two groups: individuals with AD (n = 19) and non-demented (ND) controls (n = 19). To validate the results, we measured antibody levels in plasma samples from AD patients (n = 96), mild cognitive impairment (MCI; n = 91), and ND controls (n = 97). To further explore the invlovement of EBV, we performed epitope masking immunofluorescence microscopy analysis and tests to induce lytic replication using the B95–8 cell line. ResultsIn this study, we analyzed high-resolution epitope-specific serum antibody levels in AD, revealing significant disparities in antibodies targeting multiple epitopes between the AD and control groups. Particularly noteworthy was the significant down-regulation of antibody (anti-DG#29) targeting an epitope of Epstein-Barr virus nuclear antigen 1 (EBNA1). This down-regulation increased AD risk in female patients (odds ratio up to 6.6), but not in male patients. Our investigation further revealed that the down-regulation of the antibody (anti-DG#29) is associated with EBV reactivation in AD, as indicated by the analysis of EBV VCA IgG or IgM levels. Additionally, our data demonstrated that the epitope region on EBNA1 for the antibody is hidden during the EBV lytic reactivation of B95–8 cells. ConclusionOur findings suggest a potential relationship of EBV in the development of AD in female. Moreover, we propose that antibodies targeting the epitope (DG#29) of EBNA1 could serve as valuable indicators of AD risk in female.

Clinical and prognostic associations of anti-Jo-1 antibody levels in patients with antisynthetase syndrome

ObjectiveTo investigate the association of serum anti-Jo-1 antibody levels with the disease activity and prognosis in anti-Jo-1-positive patients with antisynthetase syndrome (ASS).MethodsThis study included 115 anti-Jo-1-positive patients with ASS who were admitted to China-Japan Friendship Hospital between 2009 and 2019. Anti-Jo-1 antibody serum levels at initial admission and follow-up were determined by enzyme-linked immunosorbent assay (ELISA). Global and organ disease activity was assessed at baseline and follow-up according to the International Myositis Assessment and Clinical Studies guidelines.ResultsAmong enrolled patients, 70 (60.9%) patients initially presented with interstitial lung disease (ILD), and 46 (40%) patients presented with with muscle weakness at initial admission. At baseline, patients with ILD had lower levels of anti-Jo-1 antibodies than those without ILD (p = 0.012). Baseline anti-Jo-1 antibody levels were higher in patients with muscle weakness, skin involvement, and arthritis (all p < 0.05) compared to those without these manifestations. Baseline anti-Jo-1 antibody levels were positively correlated with skin visual analogue scale (VAS) scores (r = 0.25, p = 0.006), but not with disease activity in other organs. However, changes in anti-Jo-1 antibody levels were significantly positively correlated with the changes in PGA (β = 0.002, p = 0.001), muscle (β = 0.003, p < 0.0001), and pulmonary (β = 0.002, p = 0.013) VAS scores, but not with skin and joint VAS scores. Older age of onset (hazard ratio [HR] 1.069, 95% confidence interval [CI]:1.010–1.133, p = 0.022) and higher C-reactive protein (CRP) levels (HR 1.333, 95% CI: 1.035–1.717, p = 0.026) were risk factors for death.ConclusionAnti-Jo-1 titers appear to correlate more with disease activity changes over time rather than with organ involvement at baseline, which provides better clinical guidance for assessing the disease course using anti-Jo-1 levels.

#2553 Circulating anti-slit diaphragm NEPHRIN and KIRREL-2 antibodies associate with nephrotic syndrome

Abstract Background and Aims Pathogenesis of Idiopathic Nephrotic Syndrome (INS) is still largely unknown. Recently, circulating anti-NEPHRIN antibodies have been proposed as responsible of disarrangement of the slit diaphragm architecture upon glomerular deposition. However, previous experience referred to limited cases and controls with different ELISA assays for antibodies detection. We compared the performance of three different ELISA assays quantifying circulating anti-NEPHRIN antibodies and we developed ELISA assays to quantify circulating antibodies against two proteins homologous of NEPHRIN, the KIRREL.1 and KIRREL-2. Method We compared the performance of three different ELISA assays, two against the extracellular (aa 1-1055NEPHRIN-A and aa 23-1029 NEPHRIN-B) and one against the intracytoplasmic (aa 1160-1241 NEPHRIN-C) domain of NEPHRIN. We tested a large cohort of 166 patients (396 serum samples) with INS, 32 focal segmental glomerulosclerosis kidney transplant recipients, 143 healthy controls and 40 lupus nephritis and membranous nephropathy, respectively. Furthermore, to investigate sensitivity and specificity of circulating anti-NEPHRIN antibodies, we developed ELISA assays to quantify circulating antibodies against two proteins homologous of NEPHRIN, the KIRREL-1 and KIRREL-2. We tested NEPHRIN and KIRREL-2 gene expression among glomeruli in kidney biopsies from 4 FSGS patient and 4 controls. Results Serum levels of anti-NEPHRIN antibodies against the two extracellular domains were highly correlated, but differed significantly to the levels detected using the intracytoplasmic domain of NEPHRIN. Neither the circulating anti-NEPHRIN targeting the extracellular nor the intracellular domains of the protein could differentiate INS patients overall from healthy controls (Fig. 1A). However, after age stratification, we found that circulating anti-NEPHRIN antibodies against the extracellular domain were significatively higher in INS than in healthy controls &amp;gt;6 years old (Fig. 1B).Circulating anti-NEPHRIN antibodies against extracellular domain appeared more specific for INS than anti-NEPHRIN antibodies against cytoplasmic domain. Circulating anti-NEPHRIN antibodies did not correlate with disease activity nor FSGS recurrence after kidney transplant (Fig. 1C). Of note, circulating anti-KIRREL-2 antibodies could differentiate INS and healthy controls more effectively than anti-NEPHRIN antibodies (Fig. 1D). We than confirmed that KIRREL-2 is transcript in glomeruli (Fig. 1E) and, in line with circulating anti-KIRREL-2 antibodies, spatial transcriptomic analyses showed that KIRREL-2 is increased in FSGS than in controls. Conclusion In a large cohort of patients, we showed that circulating anti-NEPHRIN antibodies are positive in a subset of INS and FSGS recurrence. However, they are not associated with disease activity and the circulating levels appeared as age related. Circulating anti-KIRREL-2 antibodies are more strongly associated with INS. Therefore, based on our findings, several podocyte antigens may be supposed target for specific autoantibodies in INS.

Immune response and laboratory markers in the spectrum of severity of COVID-19

BACKGROUND: Serum antibodies to SARS-CoV-2, when measured early after disease onset, may add value to the diagnosis of COVID-19. AIM: To examine the levels of serum antibodies to SARS-CoV-2 and laboratory blood parameters in hospitalized patients with COVID-19 of varying severity. MATERIALS AND METHODS: In this retrospective cohort study, we examined laboratory markers of inflammation in patients with acute COVID-19 during the 1st week of hospitalization. The levels of serum antibodies to SARS-CoV-2 were studied using commercial test systems. RESULTS: In 47% of hospitalized patients with COVID-19, during the first week of hospital stay, IgM and IgG antibodies to SARS-CoV-2 were detected, both in the case of a positive and negative PCR test. An average positive cor- relation of detected IgM and IgG with antibodies to the receptor-binding site of the S-protein of the SARS-CoV-2 virus is shown. In total, IgM and IgG antibodies to SARS-CoV-2 were most often detected in patients with a favorable course of the disease. Laboratory parameters in patients with moderate and severe COVID-19 were characterized by asignificant increase in the level of serum C-reactive protein, an increase in the neutrophil-leukocyte ratio and fibrinogen level, in comparison with data from patients with a mild course of the disease. In mild cases of infection, a moderately negative correlation was revealed between the levels of antibodies to SARS-CoV-2 and NLR. CONCLUSIONS: Detection of antibodies to SARS-CoV-2 in the early stages of hospitalization may be a predictor of a favorable outcome of the disease and serve as an additional criterion for the diagnosis of COVID-19 along with PCR analysis.

Acupoint application for Hashimoto's thyroiditis with liver-qi stagnation: a randomized controlled trial

To observe the clinical efficacy and safety of acupoint application for Hashimoto's thyroiditis (HT) with liver-qi stagnation. One hundred and fifty patients of HT with liver-qi stagnation were randomly divided into an acupoint application group (75 cases, 11 cases were excluded, 5 cases dropped out) and a control group (75 cases, 12 cases excluded, 3 cases dropped out). Based on the health education combined with conventional western medicine treatment, the patients in the acupoint application group were treated with acupoint application, while the patients in the control group were treated with placebo acupoint application. Shenque (CV 8), bilateral Yongquan (KI 1), Yeshi, and ashi point were selected in both groups, with Yeshi treated once a week and the remaining acupoints treated every other day, for a total of 4 weeks. The serum levels of thyroglobulin antibody (TgAb), thyroid peroxidase antibody (TPOAb), free triiodothyronine (FT3), free thyroxine (FT4), and thyroid-stimulating hormone (TSH), as well as the thickness of thyroid left lobe, right lobe, and isthmus, TCM symptom score, hospital anxiety and depression scale (HADS) score, and MOS 36-item short form health survey (SF-36) score were compared between the two groups before and after treatment. Adverse reactions in both groups were observed. Compared with before treatment, in the acupoint application group, the serum levels of TgAb and TPOAb were reduced after treatment (P<0.05), and the scores of role physical (RP), body pain (BP), vitality (VT), role emotional (RE), and mental health (MH) in SF-36 were increased after treatment (P<0.01, P<0.001). The thickness of the thyroid isthmus after treatment was smaller than that before treatment (P<0.05), and the TCM symptom scores and HADS anxiety (HADS-A) scores after treatment were lower than those before treatment (P<0.001, P<0.01) in both groups. In the control group, the scores of physical function (PF), RP, BP, VT, and RE in SF-36 after treatment were higher than those before treatment (P<0.05, P<0.01, P<0.001). There was no statistically significant difference in serum FT3, FT4, and TSH levels within the groups (P>0.05). There was no statistically significant difference in the above indexes between the two groups (P>0.05). The incidence of adverse reactions in the acupoint application group and the control group was 20.0% (15/75) and 10.7% (8/75) respectively, with skin allergy being the main adverse reaction. Acupoint application could reduce the serum levels of TgAb and TPOAb in patients of HT with liver-qi stagnation, alleviate thyroid enlargement, improve TCM symptoms and anxiety, and improve quality of life, with safe and reliable clinical efficacy.

Clinical application of serum seven tumour-associated autoantibodies in patients with pulmonary nodules

BackgroundThe incidence of pulmonary nodules is increasing because of the promotion and popularisation of low-dose computed tomography (LDCT) screening for populations with suspected lung cancer. However, a high rate of false positives and concerns regarding the radiation-related cancer risk of repeated CT scanning remain major obstacles to its wide application. This study aimed to investigate the clinical value of seven tumour-associated autoantibodies (7-TAAbs) in the differentiation of malignant pulmonary tumours from benign ones and the early detection of lung cancer in routine clinical practice. MethodsWe included 377 patients who underwent both the 7-TAAbs panel test and LDCT screening, and were diagnosed with pulmonary nodules using LDCT. An enzyme-linked immunosorbent assay (ELISA) was used to measure the serum levels antibodies for P53, PGP9.5, SOX2, GAGE7, GBU4-5, CAGE, and MAGE-A1. The relationships between the positive rates of the 7-TAAbs and the patient sex, and age, and the number, size, and composition of pulmonary nodules were analysed. We then statistically evaluated the clinical application value. ResultsThe positive rates of the 7-TAAbs did not correlate with sex, age, number, size, or composition of pulmonary nodules. The serum antibody level of GBU4-5 in patients with pulmonary nodules tended to increase with age; the serum antibody level of SOX2 tended to increase with nodule size and was the highest among patients with mixed ground-glass opacity (mGGO) nodules. The antibody positive rate for CAGE in female patients with pulmonary nodules was significantly higher than that in male patients (P < 0.05). The positive rate of GBU4-5 antibody in patients aged 60 years and above was higher than that in younger patients (P < 0.05). The positive rate of GAGE7 antibody in patients with pulmonary nodules sized 8–20 mm was also significantly higher than that in patients with pulmonary nodules sized less than 8 mm (P < 0.01). Significant differences were observed in the GAGE7 antibody levels of patients with pulmonary nodules of different compositions (P < 0.01). The positive rate of the 7-TAAbs panel test in patients with lung cancer was significantly higher than in patients with pulmonary nodules (P < 0.01). Serum levels of P53, SOX2, GBU4-5, and MAGE-A1 antibodies were significantly higher in patients with lung cancer than in those with pulmonary nodules (P < 0.05). ConclusionThe low positive rates of serum 7-TAAbs in patients with lung cancer and pulmonary nodules may be related to different case selection, population differences, geographical differences, different degrees of progression, and detection methods. The combined detection of 7-TAAbs has some clinical value for screening and early detection of lung cancer.

Recombinant Human Proteoglycan Aggrecan-G1 Domain-induced Arthritis (GIA) Mouse Model.

The recombinant human proteoglycan aggrecan-G1 domain (rhG1)-induced arthritis (GIA) mouse model is a complex model of rheumatoid arthritis (RA). In GIA, autoimmune arthritis is induced by repeated intraperitoneal immunization of genetically susceptible BALB/c mice with the rhG1 antigen emulsified in the adjuvant dimethyldioctadecylammonium (DDA). This article describes the steps for producing and purifying the rhG1 antigen, the immunization protocol, methods for following the clinical picture of arthritis, and the evaluation of relevant laboratory parameters. In this model, the autoimmune arthritis develops stepwise, similar to RA: First is the preclinical stage (after the first immunization, days 0-20) with no sign of inflammation but detectable T and B cell activation; next, the stage of early arthritis (after the second immunization, days 21-41), where the first definitive signs of arthritis appear together with autoantibody production; and then the severe late-stage arthritis (after the third immunization, after day 42), which presents with massive inflammation of the limbs, leading to cartilage and bone destruction and finally ankylosis. The protocols described here provide sufficient information for investigators to use the GIA model to study different aspects of autoimmune arthritis. © 2024 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol: Induction of recombinant human proteoglycan aggrecan-G1 domain (rhG1)-induced arthritis (GIA) Support Protocol 1: Production of rhG1-Xa-mFc2a fusion protein with CHOK1 mammalian expression system Support Protocol 2: Purification of the rhG1-Xa-mFc2a fusion protein by affinity chromatography Support Protocol 3: Preparation of DDA adjuvant Support Protocol 4: Clinical assessment of arthritis Support Protocol 5: Measurement of serum antibody levels and cytokines Support Protocol 6: Measurement of rhG1-induced proliferation and cytokine production in spleen cell culture Support Protocol 7: Histological assessment of arthritic limbs Support Protocol 8: Evaluation of arthritis with micro-computed tomography.

JMJD6 Autoantibodies as a Potential Biomarker for Inflammation-Related Diseases.

Inflammation is closely associated with cerebrovascular diseases, cardiovascular diseases, diabetes, and cancers, and it is accompanied by the development of autoantibodies in the early stage of inflammation-related diseases. Hence, it is meaningful to discover novel antibody biomarkers targeting inflammation-related diseases. In this study, Jumonji C-domain-containing 6 (JMJD6) was identified by the serological identification of antigens through recombinant cDNA expression cloning. In particular, JMJD6 is an antigen recognized in serum IgG from patients with unstable angina pectoris (a cardiovascular disease). Then, the serum antibody levels were examined using an amplified luminescent proximity homogeneous assay-linked immunosorbent assay and a purified recombinant JMJD6 protein as an antigen. We observed elevated levels of serum anti-JMJD6 antibodies (s-JMJD6-Abs) in patients with inflammation-related diseases such as ischemic stroke, acute myocardial infarction (AMI), diabetes mellitus (DM), and cancers (including esophageal cancer, EC; gastric cancer; lung cancer; and mammary cancer), compared with the levels in healthy donors. The s-JMJD6-Ab levels were closely associated with some inflammation indicators, such as C-reactive protein and intima-media thickness (an atherosclerosis index). A better postoperative survival status of patients with EC was observed in the JMJD6-Ab-positive group than in the negative group. An immunohistochemical analysis showed that JMJD6 was highly expressed in the inflamed mucosa of esophageal tissues, esophageal carcinoma tissues, and atherosclerotic plaques. Hence, JMJD6 autoantibodies may reflect inflammation, thereby serving as a potential biomarker for diagnosing specific inflammation-related diseases, including stroke, AMI, DM, and cancers, and for prediction of the prognosis in patients with EC.

Establishment of a mouse allergy model for Culicoides (Diptera: Ceratopogonidae).

Culicoides is a genus of ubiquitous biting midges (Ceratopogonidae). Female midges have blood-sucking habit. They not only bite and harass humans and animals but also may be an important vector of disease transmission. Therefore, building an animal allergy model caused by Culicoides biting is very beneficial for studying its pathogenesis and exploring the therapeutic methods. Kunming mice were used in this study to build the model and sensitised by two-step injection of midge extracts. Scratching behaviour and histological examination were used to check the immediate and delayed responses. Immunoglobulin E (IgE) and Immunoglobulin G (IgG) were detected using indirect enzyme-linked immunosorbent assay (ELISA) assay. Splenic cell proliferation and cytokine production were determined using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) and ELISA assays. The response of cytokine gene expression to midge stimulation was analysed through quantitative real-time polymerase chain reaction (qPCR). Behavioural results revealed a significant increase in scratching frequency among the midge-sensitised animals (p < 0.05). Histological examination showed more inflammatory cytokine infiltration at the injection site of midge-sensitised mice comparing to the ones in the control group. The serum levels of IgE and IgG1 antibodies in the midge-sensitised group were significantly elevated (p < 0.05). After splenocytes were stimulated in vitro with midge extracts, the midge-sensitised group's splenocyte count significantly increased in comparison to the control group. The midge-sensitised group's qPCR data revealed a down-regulation of tumor necrosis factor alpha (TNF-α) expression and an increase in the expression of interleukin (IL)-4, IL-5, IL-10 and IL-13 but not in the control group (p < 0.05). In this study, an animal model of Culicoides-mouse sensitisation was successfully constructed using a two-step method. The mode of administration of the model was in good agreement with the natural immune pathway, and the immune response induced by the sensitisation of the model was similar to that produced by the bite of a midge.

Higher correlation between neutralizing antibodies and surrogate neutralizing or binding antibodies in COVID-19 patients than vaccine recipients.

This study determined the seropositive rates and levels of antibodies to severe acute respiratory syndrome coronavirus-2 in 50 patients and 108 vaccinees using microneutralization test (MNT), surrogate virus neutralization test (sVNT), chemiluminescent microparticle immunoassay (CMIA), and electrochemiluminescence immunoassay (ECLIA). MNT, as the reference method, employed living clade S and Delta viruses to measure neutralizing (NT) antibodies, while sVNT employed wild type strain and Delta receptor-binding domains (RBD) as the test antigens to measure sVNT antibodies. CMIA and ECLIA employed only one version of RBD to measure the binding antibodies. Our study performed S gene sequencing of the test virus to exclude undesired mutants that might lead to changes in antibody levels in MNT assay. We showed that spike protein amino acid sequences of our Delta virus contained 13 amino acid changes, with 3 related to the reduced neutralization. The MNT assay showed a significant reduction in seropositive rates and antibody levels in the patients' sera when the Delta variant replaced clade S as the test virus. In contrast, the seropositive rates determined by sVNT assay using wild type strain RBD and Delta RBD were non-significantly different, suggesting that sVNT assay could not identify the difference between the antigenicity of wild type RBD and Delta RBD. Furthermore, the correlation between the levels of NT and sVNT antibodies was moderate with the patients' sera but modest with the post-vaccination sera. The seropositive rates in the patients, as determined by CMIA or ECLIA, were not different from the MNT assay using clade S, but not Delta, as the test virus. In all analyses, the correlations between the antibody levels measured by MNT and the other 3 assays were modest to moderate, with the r-values of 0.3500-0.7882.

Evaluation of Immune Protection of a Bivalent Inactivated Vaccine against Aeromonas salmonicida and Vibrio vulnificus in Turbot

The Aeromonas salmonicida is responsible for causing furunculosis in various fish species. Furunculosis is a ubiquitous disease that affects the aquaculture industry and causes the mass mortality of turbot. Vibrio vulnificus is a pathogen that causes skin ulcers and hemorrhagic septicemia in fish, resulting in significant mortality in aquaculture. In this study, we have established a bivalent inactivated vaccine against A. salmonicida and V. vulnificus with Montanide™ ISA 763 AVG as an adjuvant. This bivalent inactivated vaccine was used to immunize turbot by intraperitoneal injection, and the relevant immune indexes were detected. The results demonstrate that the bivalent inactivated vaccine exhibited a relative percent survival (RPS) of 77% following A. salmonicida and V. vulnificus intraperitoneal challenge. The vaccinated group exhibited higher levels of acid phosphatase activity and lysozyme activity compared to the control group. ELISA results showed a significant increase in serum antibody levels in immunized turbot, which was positively correlated with immunity. In the kidney tissue, related immune genes (TLR5, CD4, MHCI and MHCII) were up-regulated significantly, showing that the vaccine can induce cellular and humoral immune responses in turbot. In conclusion, the bivalent inactivated vaccine against A. salmonicida and V. vulnificus was immunogenic, efficiently preventing turbot from infection, which has the potential to be applied in aquaculture.

Macrophage membrane-coated Eucommia ulmoides polysaccharides-loaded PLGA nanoparticles as an effective antigen-targeted delivery system

Polysaccharides derived from Eucommia ulmoides leaves have immune-regulating, hypoglycemic, anti-tumor, and other beneficial functions. As a drug delivery system, polylactic-glycolic acid copolymer (PLGA) offers advantages like immunogenicity enhancement, improved drug absorption, and increased drug bioavailability. Currently, macrophage membranes are successfully employed in biomimetic nanomaterials to enhance drug utilization and extend drug administration time in the body, exhibiting good immunogenicity and organ targeting. In this study, we developed biomimetic PsEUL PLGA nanoparticles (NPs) coated with macrophage membrane (MM-PPsEUL) and examined their immune activity in vitro and in vivo. In vitro, MM-PPsEUL increased the phagocytic efficiency of macrophages without affecting their activity. In vivo, MM-PPsEUL significantly elevated the immune organ index of mice and upregulated the level of ovalbumin-specific IgG antibodies in serum. Simultaneously, it increased the expressions of cytokines IFN-γ and IL-4, as well as the levels of TLR4, MyD88, TRAF6, and NF-κB p65 proteins in mice spleen. MM-PPsEUL also exhibited a targeting effect on inguinal lymph nodes and slowed down the release rate of antigens, thereby inducing a prolonged immune response. In summary, MM-PPsEUL provides sustained release capabilities and can induce both humoral and cellular immune responses. This makes MM-PPsEUL NPs a promising antigen-targeted delivery system.

Investigation of an Mpox Outbreak Affecting Many Vaccinated Persons in Chicago, Illinois-March 2023-June 2023.

After months of few mpox cases, an increase in cases was reported in Chicago during May 2023, predominantly among fully vaccinated (FV) patients. We investigated the outbreak scope, differences between vaccinated and unvaccinated patients, and hypotheses for monkeypox virus (MPXV) infection after vaccination. We interviewed patients and reviewed medical records to assess demographic, behavioral, and clinical characteristics; mpox vaccine status; and vaccine administration routes. We evaluated serum antibody levels after infection and compared patient viral genomes with MPXV sequences in available databases. We discussed potential vaccine compromise with partners who manufactured, handled, and administered the vaccine associated with breakthrough infections. During 18 March-27 June 2023, we identified 49 mpox cases; 57% of these mpox patients were FV. FV patients received both JYNNEOS doses subcutaneously (57%), intradermally (7%), or via heterologous administration (36%). FV patients had more median sex partners (3; interquartile range [IQR] = 1-4) versus not fully vaccinated patients (1; IQR = 1-2). Thirty-six of 37 sequenced specimens belonged to lineage B.1.20 of clade IIb MPXV, which did not demonstrate any amino acid changes relative to B.1, the predominant lineage from May 2022. Vaccinated patients demonstrated expected humoral antibody responses; none were hospitalized. No vaccine storage excursions were identified. Approximately 63% of people at risk for mpox in Chicago were FV during this period. Our investigation indicated that cases were likely due to frequent behaviors associated with mpox transmission, even with relatively high vaccine effectiveness and vaccine coverage. Cases after vaccination might occur in similar populations.

Francisella tularensis-specific antibody levels in sera from Swedish patients with suspected tularemia during a 13-year period.

For a majority of tularemia patients, serology is the basis for the diagnosis. The aim of this study was to perform an analysis of the samples analyzed at a Swedish reference laboratory for the presence of Francisella tularensis-specific antibody levels in sera from individuals with suspected tularemia. Annual and monthly variations of the total number of samples and proportions of positive samples were analyzed, as well as the influence of age and gender. We performed a retrospective analysis of the presence of F. tularensis-specific antibodies in serological samples from patients with suspected tularemia analyzed during the period 2010 - 2022 at the University Hospital of Umeå in Sweden, a national reference laboratory, by use of various statistical methods. In total, some 15,100 serum samples had been analyzed for the presence of IgG and IgM antibodies by ELISA during the 13-year period. Overall, there were higher number of samples with IgG positive or borderline titers, 2,522 and 921, respectively, than with IgM positive or borderline titers, 1,802 and 409, respectively. Repeated samples were obtained from some 1,930 individuals and approximately a third of the cases, which were initially seronegative, had seroconverted when resampled. Peak number of monthly samples were recorded in August and September, > 3,000. Annual numbers varied greatly and peak numbers were observed in 2015 and 2019, 1,832 and 2,250, respectively, whereas some other years the numbers were 700 - 800. There was also much variation in the annual and monthly percentages of positive samples and they varied between less than 10% to greater than 20%. The highest percentages of positive samples were recorded in September and October. IgG and IgM titers declined with age and these differences were highly significant for IgG titers, with decreasing average titers for each 20-year interval. Collectively, the data demonstrate the marked annual and seasonal variations in tularemia sampling occurring in Sweden. Also, the proportion of positive samples increased during months and years with peak number of samples. Another notable finding was that average antibody titers decreased with increased age.

Experimental trials of predicted CD4+ and CD8+ T-cell epitopes of respiratory syncytial virus.

Respiratory syncytial virus (RSV) is the most common cause of viral lower respiratory tract infections (LRTIs) in young children around the world and an important cause of LRTI in the elderly. The available treatments and FDA-approved vaccines for RSV only lessen the severity of the infection and are recommended for infants and elderly people. We focused on developing a broad-spectrum vaccine that activates the immune system to directly combat RSV. The objective of this study is to identify CD4+ and CD8+ T-cell epitopes using an immunoinformatics approach to develop RSV vaccines. The efficacy of these peptides was validated through in-vitro and in-vivo studies involving healthy and diseased animal models. For each major histocompatibility complex (MHC) class-I and II, we found three epitopes of RSV proteins including F, G, and SH with an antigenic score of >0.5 and a projected SVM score of <5. Experimental validation of these peptides on female BALB/c mice was conducted before and after infection with the RSV A2 line 19f. We found that the 3RVMHCI (CD8+) epitope of the F protein showed significant results of white blood cells (19.72 × 103 cells/μl), neutrophils (6.01 × 103 cells/μl), lymphocytes (12.98 × 103 cells/μl), IgG antibodies (36.9 µg/ml), IFN-γ (86.96 ng/L), and granzyme B (691.35 pg/ml) compared to control at the second booster dose of 10 µg. Similarly, 4RVMHCII (CD4+) of the F protein substantially induced white blood cells (27.08 × 103 cells/μl), neutrophils (6.58 × 103 cells/μl), lymphocytes (16.64 × 103 cells/μl), IgG antibodies (46.13 µg/ml), IFN-γ (96.45 ng/L), and granzyme B (675.09 pg/ml). In-vitro studies showed that 4RVMHCII produced a significant level of antibodies in sera on day 45 comparable to mice infected with the virus. 4RVMHCII also induced high IFN-γ and IL-2 secretions on the fourth day of the challenge compared to the preinfectional stage. In conclusion, epitopes of the F protein showed considerable immune response and are suitable for further validation.

Expression and clinical significance of pattern recognition receptor-associated genes in hand, foot and mouth disease

Objective: To explore which pattern recognition receptors (PRRs) play a key role in the development of hand, foot, and mouth disease (HFMD) by analyzing PRR-associated genes. Methods: We conducted a comparative analysis of PRR-associated gene expression in human peripheral blood mononuclear cells (PBMCs) infected with enterovirus 71 (EV-A71) which were derived from patients with HFMD of different severities and at different stages. A total of 30 PRR-associated genes were identified as significantly upregulated both over time and across different EV-A71 isolates. Subsequently, ELISA was employed to quantify the expression of the six most prominent genes among these 30 identified genes, specifically, BST2, IRF7, 1FI16, TRIM21, MX1, and DDX58. Results: Compared with those at the recovery stage, the expression levels of BST2 (P=0.027), IFI16 (P=0.016), MX1 (P=0.046) and DDX58 (P=0.008) in the acute stage of infection were significantly upregulated, while no significant difference in the expression levels of IRF7 (P=0.495) and TRIM21 (P=0.071) was found between different stages of the disease. The expression levels of BST2, IRF7, IFI16 and MX1 were significantly higher in children infected with single pathogen than those infected with mixed pathogens, and BST2, IRF7, IFI16 and MX1 expression levels were significantly lower in coxsackie B virus (COXB) positive patients than the negative patients. Expression levels of one or more of BST2, IRF7, IFI16, TRIM21, MX1 and DDX58 genes were correlated with PCT levels, various white blood cell counts, and serum antibody levels that reflect disease course of HFMD. Aspartate aminotransferase was correlated with BST2, MX1 and DDX58 expression levels. Conclusions: PRR-associated genes likely initiate the immune response in patients at the acute stage of HFMD.