IgA Antibody Levels Research Articles

Cardiac remodeling in rheumatoid arthritis: assessing the influence of anti-CCP and rheumatoid factor

Abstract Background Anti-cyclic citrullinated peptide (anti-CCP) antibodies and rheumatoid factor (RF), markers of Rheumatoid Arthritis (RA) activity, are associated with adverse cardiovascular outcomes, suggesting a potential link between RA and cardiac remodeling. Purpose Our study aimed to explore the correlation between antibody levels (anti-CCP and RF) and left ventricular (LV) remodeling in RA patients without known heart disease. Additionally, it sought to identify other disease-related factors that correlate with LV remodeling. Methods A cross-sectional study of 124 RA patients aged ≥ 18 years, classified per the 2010 ACR/EULAR criteria, collected blood samples for CRP, and antibody levels (RF ≥ 20 IU/ml and anti-CCP ≥ 5 IU/ml via ELISA). Transthoracic echocardiography (TTE) was conducted using a linear method in a long-axis parasternal 2D window. Sixty-two patients exhibited LV remodeling and were matched with 62 patients without it. Echocardiographic variables included were those to calculate the relative wall thickness (RWT, cut-off value 0.42) and left ventricular mass index (LVMI, cut-off values of 43-95 g/m2 in women and 49-115 g/m2 in men) along with left ventricular end diastolic (LVIDd), and systolic volumes (LVIDs), and left ventricular ejection fraction (LVEF). Statistical analyses employed the Chi-square test, Student's t-test, or Mann-Whitney U test as applicable, with correlations assessed using Spearman's rho, an analysis was conducted on the area under the curve (AUC) and a significance level of p ≤ 0.05. Results The most common type of LV alteration in our study was concentric remodeling (74.2%). A statistically significant difference was observed in the levels of Anti-CCP titers 193.85 IU/ml (p < .001), RF IgM 200.00 IU/ml (p < .001) and IgA 185.5 IU/ml (p < .001) in patients with LV remodeling. Anti-CCP and RF IgA antibody levels exhibited a moderate correlation with the presence of LV remodeling, with rho 0.387 (p < .001) and rho 0.344 (p < .001), respectively. The RWT showed a moderate correlation with anti-CCP titers with rho 0.298 (p .001). AUC analysis anti-CCP titers demonstrated better diagnostic performance for the existence of cardiac remodeling (0.722, 95% CI 0.628-0.816, p < .001), RF IgA (0.696, 95% CI 0.602-790, p < .001) and IgM (0.650, 95% CI 0.563-755, p .002). Conclusion In summary, among RA patients without heart failure (HF), LV remodeling and elevated RWT correlate with antibody levels independently of traditional cardiovascular risk factors. Patients with altered LV geometry exhibit higher antibody titers, highlighting the need for RA-related biomarkers that correlate with changes in LV structure and function Recognizing association between autoimmunity and HF development holds significant implications for both prevention and treatment strategies in RA patients.

Partial Protection of Goats against Haemonchus contortus Achieved with ADP-Ribosylation Factor 1 Encapsulated in PLGA Nanoparticles.

Haemonchus contortus (H. contortus), a nematode with global prevalence, poses a major threat to the gastrointestinal health of sheep and goats. In an effort to combat this parasite, a nanovaccine was created using a recombinant ADP-ribosylation factor 1 (ARF1) antigen encapsulated within poly lactic-co-glycolic acid (PLGA). This study aimed to assess the effectiveness of this nanovaccine in providing protection against H. contortus infection. Fifteen goats were randomly divided into three groups. The experimental group received two doses of the PLGA encapsulated rHcARF1 (rHcARF1-PLGA) nanovaccine on days 0 and 14. Fourteen days after the second immunization, both the experimental and positive control groups were challenged with 8000 infective larvae (L3) of H. contortus, while the negative control group remained unvaccinated and unchallenged. At the end of the experiment on the 63rd day, all animals were humanly euthanized. The results showed that the experimental group had significantly higher levels of sera IgG, IgA, and IgE antibodies, as well as increased concentrations of cytokines, such as IL-4, IL-9, IL-17, and TGF-β, compared to the negative control group after immunization. Following the L3 challenge, the experimental group exhibited a 47.5% reduction in mean eggs per gram of feces (EPG) and a 55.7% reduction in worm burden as compared to the positive control group. These findings indicate that the nanovaccine expressing rHcARF1 offers significant protective efficacy against H. contortus infection in goats. The results also suggest the need for more precise optimization of the antigen dose or a reassessment of the vaccination regimen. Additionally, the small sample size limits the statistical rigor and the broader applicability of the findings.

Study of the Effects of Alfalfa Bioactive Substances and Polysaccharides on the Lactation Performance and Immune Function of Dairy Cows

Background: The aim of this study was to investigate the effects of alfalfa polysaccharides on the lactation performance and immune function of dairy cows. Methods: A total of 84 healthy Holstein cows were selected and randomly divided into 7 groups, including the control Group A0, the alfalfa polysaccharide groups (AP1, AP2, AP3) and the alfalfa extract groups (AE1, AE2, AE3). Each group had three replicates and each replicate had four cows. The daily rations of the dairy cows in the AP group and the AE group were supplemented with alfalfa polysaccharide powder and alfalfa extract at concentrations of 1, 2 and 3 kg/t, those in the A0 group served as a control. Result: (1) the milk production of dairy cows in the AE groups was extremely significantly greater (p less than 0.01) than that in A0 group and AP groups. The milk protein content of cows in the AP2 and AE2 groups was significantly greater (P less than 0.05) than that in the A0 group (2) The interleukin-2 (IL-2) levels in the serum of cows in the AP2, AP3, AE2 and AE3 groups were greater than those in the A0 and AP1 groups and the IgM antibody levels in the AP group and the AE group were extremely significantly greater than those in the A0 and AP1 groups (P less than 0.01). The IgA antibody level in the serum of dairy cows in the AP2, AP3, AE2 and AE3 groups was significantly (P less than 0.01) greater than that in the A0, AP1 and AE1 groups. In summary, the alfalfa extract improved both the lactation performance and immunity of dairy cows, indicating comprehensive effects. Alfalfa polysaccharides at a concentration of 2 kg/t improved the immunity of dairy cows.

Local Inflammatory and Systemic Antibody Responses Initiated by a First Intradermal Administration of Autogenous Salmonella-Killed Vaccines and Their Components in Pullets

Vaccination strategies are used to manage Salmonella in chickens. Salmonella-killed vaccines are considered safer since they are inactivated. However, little is known regarding the cellular immune activities at the site of vaccine administration of Salmonella-killed vaccines. The growing feather (GF) cutaneous test has been shown to be an effective bioassay to monitor local tissue/cellular responses. We assessed local and systemic antibody responses initiated by intradermal injection of Salmonella-killed vaccines into GF-pulps of 14–15-week-old pullets. Treatments consisted of two autogenous Salmonella-killed vaccines (SV1 and SV2), S. Enteritidis (SE) lipopolysaccharide (SE-LPS), and the water-oil-water (WOW) emulsion vehicle. GF-pulps were collected before (0 h) and at 6, 24, 48, and 72 h post-GF-pulp injection for leukocyte population analysis, while heparinized blood samples were collected before (0 d) and at 3, 5, 7, 10, 14, 21, and 28 d after GF-pulp injections to assess plasma levels (a.u.) of SE-specific IgM, avian IgY (IgG), and IgA antibodies using an ELISA. Injection of GF-pulps with SV1, SV2, or SE-LPS, all in a WOW vehicle, initiated inflammatory responses characterized by the recruitment of heterophils, monocytes/macrophages, and a few lymphocytes. The WOW vehicle emulsion alone recruited more lymphocytes than vaccines or SE-LPS. The SV1 and SV2 vaccines stimulated Salmonella-specific IgM and IgA early, while IgG levels were greatly elevated later during the primary response. Overall, SV1 and SV2 stimulated a heterophil and macrophage-dominated local inflammatory- and SE-specific humoral response with an isotype switch from IgM to IgG, characteristic of a T-dependent primary antibody response. This study provides comprehensive information on innate and adaptive immune responses to autogenous Salmonella-killed vaccines and their components that will find application in the management of Salmonella in poultry.

Associations between clinical data, vaccination status, antibody responses, and post-COVID-19 symptoms in Thais infected with SARS-CoV-2 Delta and Omicron variants: a 1-year follow-up study

BackgroundSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), led to a global pandemic from 2020. In Thailand, five waves of outbreaks were recorded, with the fourth and fifth waves driven by the Delta and Omicron variants, resulting in over 20,000 new confirmed cases daily at their peaks.MethodsThis cross-sectional study investigated the associations between clinical symptoms, vaccination status, antibody responses, and post-COVID-19 sequelae in COVID-19 patients. Plasma samples and clinical data were collected from participants admitted to hospitals in Thailand between July 2021 and August 2022, with follow-ups conducted for one year. The study included 110 participants infected with either the Delta (n = 46) or Omicron (n = 64) variants. Virus genotypes were confirmed by RT-PCR of nasal swab RNA and partial nucleotide sequencing of the S gene. IgG and IgA antibody levels against the receptor-binding domain (RBD) of SARS-CoV-2 Delta and Omicron variants were measured in plasma samples using ELISA.ResultsPneumonia was found to be associated with Delta variant infections, while sore throat, congestion or runny nose, and headache were linked to Omicron infections. Vaccination with fewer than two doses and diabetes mellitus were significantly associated with higher disease severity. Specific IgG and IgA antibodies against the RBD of the Delta variant generally rose by day 14 and were maintained for up to two months, whereas the pattern of antibody response to the Omicron variant was less clear. Antibody risings were found to be positively associated with pneumonia, certain underlying conditions (obesity, hypertension, dyslipidemia, and diabetes mellitus), and age ≥ 60 years. Delta variant infections were associated with forgetfulness, hair loss, and headache during the 1-year post-infection period. Females were more likely to experience hair loss, forgetfulness, and joint pain, while older age was associated with joint pain.ConclusionsThis study enhances our understanding of SARS-CoV-2 infections in Thais, particularly concerning the Delta and Omicron variants. The findings can inform public health planning and response strategies for future outbreaks of SARS-CoV-2 or other emerging viral diseases.

Genetic characteristics associated with the virulence of porcine epidemic diarrhea virus (PEDV) with a naturally occurring truncated ORF3 gene

Porcine epidemic diarrhea virus (PEDV) has emerged in American countries, and it has reemerged in Asia and Europe, causing significant economic losses to the pig industry worldwide. In the present study, the 17GXCZ-1ORF3d strain, which has a naturally large deletion at the 172–554 bp position of the ORF3 gene, together with the 17GXCZ-1ORF3c strain, was serially propagated in Vero cells for up to 120 passages. The adaptability of the two strains gradually increased through serial passages in vitro. Genetic variation analysis of the variants of the two strains from different generations revealed that the naturally truncated ORF3 gene in the 17GXCZ-1ORF3d variants was stably inherited. Furthermore, the survival, viral shedding and histopathological lesions following inoculation of piglets demonstrated that the virulence of 17GXCZ-1ORF3d-P120 was significantly attenuated. These results indicate that the naturally truncated ORF3 gene may accelerate the attenuation of virulence and is involved in PEDV virulence together with mutations in other structural genes. Importantly, immunization of sows with G2b 17GXCZ-1ORF3d-P120 increased PEDV-specific IgG and IgA antibody levels in piglets and conferred partial passive protection against heterologous G2a PEDV strains. Our findings suggest that an attenuated strain with a truncated ORF3 gene may be a promising candidate for protection against PEDV.

Serum IgA antibody level against porcine epidemic diarrhea virus is a potential pre-evaluation indicator of immunization effects in sows during parturition under field conditions

BackgroundPorcine Epidemic Diarrhea (PED) is a highly contagious disease caused by Porcine Epidemic Diarrhea Virus (PEDV), resulting in a mortality rate of suckling piglets as high as 100%. Vaccination is the primary strategy for controlling PEDV infection, however, there is currently a lack of reliable methods for assessing the efficacy of vaccination. This study aimed to analyze serum and colostrum samples from 75 parturient sows with a specific vaccination strategy to measure levels of IgG, IgA, and neutralizing antibodies (nAbs) against PEDV, and to investigate the correlation between serum and colostrum antibody levels, as well as to identify potential biomarkers that can be used to evaluate immunization effects under field conditions.ResultsThe findings of correlation analysis between antibody levels of IgA, IgG, and nAbs in serum or colostrum samples revealed that IgG demonstrated the most robust correlation with nAbs exhibiting a correlation coefficient of 0.64 in serum samples. Conversely, IgA exhibited the highest correlation with nAbs, with a correlation coefficient of 0.47 in colostrum samples. Additionally, the correlation analysis of antibody levels between serum and colostrum samples indicated that serum IgA displayed the strongest correlation with colostrum IgA, with a coefficient of 0.63, indicating that serum IgA may serve as a viable alternative indicator for evaluating IgA levels in colostrum samples. To further evaluate the suitability of serum IgA as a substitute marker for colostrum IgA, levels of IgA antibodies in serum samples from sows were examined both pre- and post-parturition. The findings indicated that serum IgA levels were initially low prior to the initial immunization, experienced a notable rise 21 days after immunization, and maintained a significant elevation compared to pre-immunization levels from 21 days pre-parturition to 14 days postpartum, spanning a total of 35 days.ConclusionsSerum anti-PEDV IgA antibody levels may serve as a valuable predictor for immunization effects, allowing for the assessment of colostrum IgA antibody levels up to 21 days in advance. This insight could enable veterinarians to timely adjust or optimize immunization strategies prior to parturition, thereby ensuring adequate passive immunity is conferred to piglets through colostral transfer postpartum.

Low Salivary IgA Levels Against PAc (361-386) as a Risk Factor for Root Caries in Older Adults.

This study aimed to assess the intricate relationship between salivary IgA antibody levels to PAc (361-386) (PPA), mutans streptococci colonization, and root caries development in older adults. This study included 307 participants aged 76 years residing in Niigata city, Japan. Clinical oral examinations were performed at baseline in 2004 and 1 year later, during which the total number of untreated and treated root caries was assessed using the root decayed, filled tooth (DFT) index. The stimulated saliva samples were collected using the spitting method during the baseline survey. Salivary IgA antibody levels to amino acid residues 361-386 of Streptococcus mutans PAc were quantified using an enzyme-linked immunosorbent assay. Statistical analyses, including the χ2 test, Mann-Whitney U test, and logistic regressions, were performed to examine the association of increased root DFT with the independent variables. Among the 307 participants (53.1% men), the mean root DFT at baseline was 3.77 ± 3.66, and 36.5% of the study sample exhibited increased root DFT after 1 year with a mean increment of 0.36 ± 0.48. Participants with increase in root DFT after 1 year had significantly higher rates of low PPA levels (≤ 25th percentile) than those without increased root DFT (p = 0.020). Low PPA levels (≤ 25th percentile) were significantly more likely to have an increased risk of root caries development compared with PPA levels > 25th percentile (adjusted OR: 1.88, 95% CI: 1.09-3.25). Low PPA levels and root caries incidence correlated significantly, suggesting that low levels of salivary IgA antibody to PAc (361-386) may serve as a risk factor for increased root caries in older adults.

Quantity and Quality of Naturally Acquired Antibody Immunity to the Pneumococcal Proteome Throughout Life.

Young children and older adults are susceptible for invasive pneumococcal disease (IPD) caused by Streptococcus pneumoniae. Pneumococcal protein-specific antibodies play a protective role against IPD; however, not much is known about the pace of acquisition, maturation, and maintenance of these antibodies throughout life. Immunoglobulin G (IgG) and IgA levels, avidity, and/or specificity to the pneumococcal proteome in serum and saliva from healthy young children, adults, and older adults, with known carriage status, were measured by enzyme-linked immunosorbent assay (ELISA) and 2-dimensional western blotting against ΔcpsTIGR4. Eleven-month-old children, the youngest age group tested, had the lowest pneumococcal proteome-specific IgG and IgA levels and avidity in serum and saliva, followed by 24-month-old children and were further elevated in adult groups. Among adult groups, the parents had the highest serum and saliva IgG and IgA antibody levels. In children, antibody levels and avidity correlated with daycare attendance and presence of siblings, posing as proxy for exposure and immunization. Immunodominance patterns slightly varied throughout life. Humoral immunity against the pneumococcal proteome is acquired through multiple episodes of pneumococcal exposure. Low-level and low-avidity antiproteome antibody profiles in young children may contribute to their IPD susceptibility, while in overall antiproteome antibody-proficient older adults other factors likely play a role.

Clinical efficacy of ganciclovir combined with transfer factor oral solution for pediatric infectious mononucleosis

This study investigates the clinical efficacy of ganciclovir combined with transfer factor oral solution in the treatment of patients with infectious mononucleosis (IM) to provide a reference for clinical application. A total of 150 children with IM who received treatment in our hospital from 2020 to 2022 were randomly selected as the research subjects. They were randomly divided into a control group receiving intravenous administration of ganciclovir (n = 75) and an observation group receiving transfer factor oral liquid in combination with intravenous administration of ganciclovir (n=75). The results showed that after treatment, the serum levels of CK-MB, CK, CRP, IL-6, and TNF-α were significantly reduced in both groups. The observation group showed lower levels than the control group. Additionally, peripheral blood CD4+ T cells, CD4+/CD8+ ratio, and Tfr expression were higher in the observation group compared to the control group, while the level of CD8+ T cells was lower than that of the control group. Furthermore, there were no significant changes in the levels of IgA, IgM, and IgG antibodies in the two groups before and after treatment. In conclusion, the combination therapy of transfer factor oral solution and ganciclovir demonstrates favorable clinical efficacy and safety in the treatment of children with IM, as it effectively reduces inflammatory reactions, regulates cellular immune function, promotes Tfr differentiation, and shortens recovery time.

A novel bacterium-like particles platform displaying antigens by new anchoring proteins induces efficacious immune responses.

Bacterium-like particles (BLP) are the peptidoglycan skeleton particles of lactic acid bacteria, which have high safety, mucosal delivery efficiency, and adjuvant effect. It has been widely used in recent years in the development of vaccines. Existing anchoring proteins for BLP surfaces are few in number, so screening and characterization of new anchoring proteins are necessary. In this research, we created the OACD (C-terminal domain of Escherichia coli outer membrane protein A) to serve as an anchoring protein on the surface of BLP produced by the immunomodulatory bacteria Levilactobacillus brevis 23017. We used red fluorescent protein (RFP) to demonstrate the novel surface display system's effectiveness, stability, and ability to be adapted to a wide range of lactic acid bacteria. Furthermore, this study employed this surface display method to develop a novel vaccine (called COB17) by using the multi-epitope antigen of Clostridium perfringens as the model antigen. The vaccine can induce more than 50% protection rate against C. perfringens type A challenge in mice immunized with a single dose and has been tested through three routes. The vaccine yields protection rates of 75% for subcutaneous, 50% for intranasal, and 75% for oral immunization. Additionally, it elicits a strong mucosal immune response, markedly increasing levels of specific IgG, high-affinity IgG, specific IgA, and SIgA antibodies. Additionally, we used protein anchors (PA) and OACD simultaneous to show several antigens on the BLP surface. The discovery of novel BLP anchoring proteins may expand the possibilities for creating mucosal immunity subunit vaccines. Additionally, it may work in concert with PA to provide concepts for the creation of multivalent or multiple vaccines that may be used in clinical practice to treat complex illnesses.

Persistence of COVID-19 Human Milk Antibodies After Maternal COVID-19 Vaccination: Systematic Review and Meta-Regression Analysis.

The World Health Organization (WHO) declared COVID-19 a pandemic. The Centers for Disease Control and Prevention (CDC), WHO, and American College of Obstetricians and Gynecologists (ACOG) recommend vaccination of pregnant and lactating women, aiming to protect both mothers and their infants through transplacental and human milk antibody transmission. This study aims to assess the quantity of antibodies in human milk and determine the effect of time, vaccine type, and dose on antibody level. Single-arm prospective observational studies reportingthe COVID-19-specific antibody level in human milk after COVID-19 vaccination during pregnancy or lactation were included. PubMed, Scopus, Cochrane, EBSCO, and Web of Science were searched from December 2019 to November22, 2022. Data were extracted in a uniform Google sheet.A total of 2657 studies were identified. After the removal of duplicates and screening, 24 studies were included in the systematic review and meta-regression. Human milk COVID-19-specific antibody levels increased with subsequent vaccine doses, as reflected by a positive relationship for the second (coefficient=0.91, P-value 0.043 for IgA and coefficient=1.77, P-value 0.009 for IgG) and third (coefficient=1.23, P-value 0.0029 for IgA and coefficient=3.73, P-value 0.0068 for IgG)doses. The antibody level exhibited a weak positive relationship with the follow-up time (coefficient=0.13, P-value 0.0029 for IgA and coefficient=0.18, P-value 0.016 for IgG). Only one of the 38 infants showed detectable COVID-19 IgM and IgA antibody levels in their blood. There wasan increase in the neutralizing activity of COVID-19 antibodies in human milk following the COVID-19 vaccination. From the analysis of published data, we found high positive levels of antibodies in human milk that increased with subsequent doses. Additionally, the human milk antibodies exhibit a positive neutralizing effect. Only one infant had detectable COVID-19 IgM+IgA antibodies in the blood. Further research is needed to discuss infant protection through a mother'svaccination.

Cryptosporidiosis Detection Using Immunoglobulin a Serum with Enzyme-Linked Immunosorbent Assay Method

Background: Cryptosporidiosis is still one of the most common intestinal protozoan infections found in developing countries, affecting children and adults. Cryptosporidium sp. infection activates the immune response by secreting high levels of specific Cryptosporidium IgA antibodies during the infection process. IgA can be examined by ELISA to establish a diagnosis of cryptosporidiosis. Methods: The purpose of this study was to determine the results of Cryptosporidiosis detection with serum IgA ELISA. This study was a quantitative descriptive study with 39 samples collected from children to adults using consecutive sampling technique. Data obtained from the study results were processed by univariate analysis and presented in tabular form to see the frequency distribution. Result: The results of the study involving 39 respondents revealed that the most prevalent age groups were 6-11 years old and 36-45 years old, with the majority being female. Among the 39 samples examined using the ELISA method, the Optical Density ranged from 0.059 to 1.393. One sample (2.56%) tested positive for IgA Cryptosporidium sp., specifically from age 55 years (16.6%) and male participants (20%). Conclusion: The study concluded that the Optical Density value of the positive ELISA examination was 1.393 with one sample found positive for Cryptosporidiosis from a 55 years old male. Keywords: [Cryptosporidium sp., IgA, ELISA]

Impact of RYGB surgery on plasma immunoglobulins: association between blood pressure and glucose levels six months after surgery.

We aimed to study levels of natural antibodies in plasma, and their associations to clinical and fecal biomarkers, before and 6 months after Roux-en-Y gastric bypass (RYGB) surgery. Thirty individuals with obesity [16 type 2 diabetic, 14 non-diabetic (ND)] had RYGB surgery. Total plasma IgA, IgG and IgM antibody levels and specific antibodies to oxidized low-density lipoprotein (oxLDL), malondialdehyde-acetaldehyde adducts, Porphyromonas gingivalis gingipain A hemagglutinin domain (Rgp44), and phosphocholine were measured using chemiluminescence immunoassay. Associations between plasma and fecal antibodies as well as clinical markers were analyzed. RYGB surgery reduced blood pressure, and the glycemic state was improved. A higher level of diastolic blood pressure was associated with lower plasma antibodies to oxLDL after surgery. Also, lower level of glucose markers associated with lower level of plasma antibodies to bacterial virulence factors. Antibodies to oxLDL decreased after surgery, and positive association between active serum lipopolysaccharide and specific oxLDL antibodies was detected. Total IgG levels decreased after surgery, but only in ND individuals. Reduced level of total plasma IgG, improved state of hypertension and hyperglycemia and their associations with decreased levels of specific antibodies in plasma, suggest an improved state of systemic inflammation after RYGB surgery.

Assessment of the reliability of serological monitoring results based on biobank materials

Aim. To evaluate the safety of immunoglobulins (Ig) of different classes (IgA, IgM, IgG, IgE) under conditions of long-term low-temperature storage of blood serum samples.Material and methods. The work used samples of blood serum from the collection of the Department of Epidemiology, examined by enzyme immunoassay for antibodies of classes IgA, IgM, IgG, IgE twice as follows: immediately upon receipt in the laboratory and after storage at a temperature of -70о C for 8 years.Results. After the storage of seropositive sera, the level of IgA antibodies did not change significantly (p=0,7). For the remaining classes of immunoglobulins (IgM, IgG, IgE), a small (not >15%) but significant decrease (p<0,05), most pronounced for IgE, was observed. It was shown that the higher the antibody level in the samples during the first study, the more it decreased after long-term storage (correlation at p<0,05). This did not lead to false negative results, which is due to the greater accuracy in measuring small values.Conclusion. Long-term low-temperature storage of serum samples in biobank conditions ensures the safety of antibodies of different classes and is the basis for the reliability of future studies.

Antibody response to enterotoxigenic Bacteroides fragilis of Filipino colorectal cancer patients.

Several species of the gut microbiota have been implicated in colorectal cancer (CRC) development. The anaerobic bacterium enterotoxigenic Bacteroides fragilis (ETBF), has been identified to produce fragilysin, a toxin known to cleave E-cadherin, thereby leading to carcinogenesis. To determine the antibody response of CRC patients against ETBF to ascertain whether significant difference exists or whether antibody response is related to tumor grade and tumor stage. Informed consent was obtained from histologically confirmed CRC casesand their age- and sex-matched clinically healthy controls. Plasma samples from the participants were subjected to in-house enzyme-linked immunosorbent assay (ELISA) to determine their antibody levels. Using ETBF total protein as coating antigen, 38/39 (97%) CRC cases and 36/39 (92%) controls showed anti-ETBF IgG above cut-off, while all (100%) CRC cases and 36/39 (92%) controls had anti-ETBF IgA levels above cut-off. With culture broth as coating antigen, all (100%) CRC cases and 37/39 (95%) controls had anti-ETBF IgG levels above cut-off. For anti-ETBF IgA, all (100%) cases and controls had levels above cut-off. Statistical analysis reveals no significant difference (P > 0.05) on the number of CRC cases and controls with IgG and IgA antibody levels above cut-off value. Also, there's no significant difference (P > 0.05) in the mean anti-ETBF antibody levels of cases who were at different tumor grade (well differentiated and moderately and poorly differentiated) and tumor stage (early and advanced). These results suggest that Filipino CRC cases and their clinically healthy matched controls exhibit antibody responses against ETBF.

Effect of Chitosan (Chi)-C Terminal 30 Amino Acids of Clostridium Perfringens Enterotoxin (CPE30)-pVP1 Nanoparticles on Rats with Viral Myocarditis

Coxsackie B3 virus (CVB3) is the most common pathogen of viral myocarditis (VMC), and it is necessary to study an efficient vaccine to prevent the VMC. In this research, chitosan (chi)-C-terminal 30 amino acid (CPE30) was prepared by chemical coupling, and then chi-CPE30-pcDNA3.1-VP1 plasmid (pVP) complex particles were formed by co-aggregation method. The biological characteristics of the chi-CPE30-pVP1 complex particles were analyzed. It was immunized into SD rats intranasally at different time points as a vaccine together with other by-products (such as chi-pVP1, chi-CPE30-pcDNA3.1, and chi-pcDNA3.1). 100 μg of plasmid was inoculated each time, with 4 times in total, and the specific antibody level and cellular immune response of all rats were detected. It was revealed that based on the coupling effect of ethylcarbodiimide hydrochloride and N-hydroxysuccinimide (EDC/NHS) chemical coupling reagent, nearly 70% of CPE30 was coupled to chi, and the efficiency of chi-CPE30 to wrap DNA was close to 100%. After a certain concentration of pVP1 solution was added, the chi-CPE30-pVP1 composite particles were obtained, and the surface of the chi-CPE30-pVP1 composite was scanned as spherical particles. When used as a vaccine, the composite particles can induce high serum immunoglobulin G (IgG) and mucosal IgA antibody levels in rats. Meantime, the specific lymphocyte proliferation test confirmed that chi-CPE30-pVP1 effectively induced the proliferative response of CVB specific lymphocytes in the spleen and mesenteric lymph nodes (MLN). After the rats were infected with 3LD50CVB3, it was found that the weight of rats changed slightly under the action of chi-CPE30-pVP1 vaccine (P < 0.05). The creatine kinase and creatine kinase-myoglobin binding (CK-MB) levels of rats in this group were lower than those of chi-pVP1 rats and control group (P < 0.05). Applying the prepared chi-CPE30-pVP1 vaccine to immunize rats in this research could provide a new immune method for the molecular design of new vaccines and the prevention and treatment of CVB3 infection.

Intranasal G5-BGG/pDNA Vaccine Elicits Protective Systemic and Mucosal Immunity against SARS-CoV-2 by Transfecting Mucosal Dendritic Cells.

Infectious disease pandemics, including the coronavirus disease 2019 pandemic, have heightened the demand for vaccines. Although parenteral vaccines induce robust systemic immunity, their effectiveness in respiratory mucosae is limited. Considering the crucial role of nasal-associated lymphoid tissue (NALT) in mucosal immune responses, in this study, the intranasal complex composed of G5-BGG and antigen-expressing plasmid DNA (pSP), named G5-BGG/pSP complex, is developed to activate NALT and to promote both systemic and mucosal immune defense. G5-BGG/pSP could traverse mucosal barriers and deliver DNA to the target cells because of its superior nasal retention and permeability characteristics. The intranasal G5-BGG/pSP complex elicits robust antigen-specific immune responses, such as the notable production of IgG antibody against several virusvariants. More importantly, it induces elevated levels of antigen-specific IgA antibody and a significant expansion of the lung-resident T lymphocyte population. Notably, the intranasal G5-BGG/pSP complex results in antigen expression and maturation of dendritic cells in nasal mucosae. These findings exhibit the potential of G5-BGG, a novel cationic material, as an effective gene carrier for intranasal vaccines to obtain robust systemic and mucosal immunity.

The Role of Chlamydia pneumoniae in the Aetiology of Autoimmune Diseases.

Introduction The most prevalent chronic human autoimmune disorder worldwide is rheumatoid arthritis. Synovial samples from acute-phase patients are polymerase chain reaction-positive for Chlamydia pneumoniae (C. pneumoniae)DNA and express chlamydial hsp60. Furthermore, anti-cyclic citrullinated peptide (anti-CCP) antibodies promote apoptosis of mature human Saos-2 osteoblasts via cell surface binding to citrullinated heat shock protein 60 (HSP60). Hence, we hypothesised that C. pneumoniae infection is associated with anti-CCP antibodies. Methods C. pneumoniae IgA and anti-CCP antibody levels were determined in 26 healthy subjects in this cross-sectional study. Serum C. pneumoniae IgA antibody levels were assessed using an enzyme-linked immunosorbent assay. Serum anti-CCP antibody levels were assessed using fluoroenzymeimmunoassay. Results There was a highly significant positive correlation between the two sets of antibodies (rs = 0.621; P = 0.0007). Linear regression analysis showed that this correlation was not the result of age or sex. Discussion A biologically plausible mechanism is put forward for these results, involving HSP60 acting as an endogenous ligand for toll-like receptor 4 (TLR4) and the interaction of TLR4 with lipopolysaccharides, which occur in the outer membrane of the C. pneumoniae elementary body. Pronounced pro-inflammatory mediator secretion then takes place. The release of Ca2+ ions may then activate local peptidylarginine deiminases, leading to the formation of CCPs and thus the reported finding. Confirmation of these results may have potential clinical implications in terms of diagnosis, including pre-symptomatic diagnosis, and treatment.

Suitability of Polymyxin B as a Mucosal Adjuvant for Intranasal Influenza and COVID-19 Vaccines.

Polymyxin B (PMB) is an antibiotic that exhibits mucosal adjuvanticity for ovalbumin (OVA), which enhances the immune response in the mucosal compartments of mice. Frequent breakthrough infections of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants indicate that the IgA antibody levels elicited by the mRNA vaccines in the mucosal tissues were insufficient for the prophylaxis of this infection. It remains unknown whether PMB exhibits mucosal adjuvanticity for antigens other than OVA. This study investigated the adjuvanticity of PMB for the virus proteins, hemagglutinin (HA) of influenza A virus, and the S1 subunit and S protein of SARS-CoV-2. BALB/c mice immunized either intranasally or subcutaneously with these antigens alone or in combination with PMB were examined, and the antigen-specific antibodies were quantified. PMB substantially increased the production of antigen-specific IgA antibodies in mucosal secretions and IgG antibodies in plasma, indicating its adjuvanticity for both HA and S proteins. This study also revealed that the PMB-virus antigen complex diameter is crucial for the induction of mucosal immunity. No detrimental effects were observed on the nasal mucosa or olfactory bulb. These findings highlight the potential of PMB as a safe candidate for intranasal vaccination to induce mucosal IgA antibodies for prophylaxis against mucosally transmitted infections.