Specific Antibody Levels Research Articles

A subunit vaccine based on P97R1, P46, P42, and P65 from Mycoplasma hyopneumoniae can induce significant immune response in piglets

Mycoplasma pneumonia (MPS), caused by Mycoplasma hyopneumoniae (Mhp), is a chronic, airborne respiratory disease that poses a significant threat to the global swine industry. The P97 and P46 proteins are major antigens of Mhp, with the R1 region of P97 possessing full adhesive capability. Studies have shown that the main antigenic regions of Mhp P42 and P65 proteins exhibit strong immunogenicity. In this study, we first linked the genes encoding P97R1 and P46 proteins to form the P97R1P65 gene and subsequently constructed three shuttle plasmids: pFBD-P97R1P46, pFBD-P97R1P46-p65, and pFBD-P65-P42. These proteins were expressed using the Bac to Bac system and formulated into subunit vaccines for mouse immunization. Mouse experiments indicated that the P97R1P46 + P65-P42 protein combination elicited higher levels of specific antibodies, IL-2, IL-4, and CD8+ T cells compared to other subunit vaccine groups, a finding further validated in subsequent mouse challenge protection experiments. Therefore, we utilized the MultiBac expression system to co-express P97R1P46, P65, and P42 proteins in the pFastMultibacDual vector for immunization experiments in piglets. The piglet immunization experiments demonstrated that the Mhp subunit vaccine prepared in this study could induce specific antibodies against Mhp, with the combination of P97R1P46, P65, and P42 proteins inducing the highest level of humoral immunity. This study provides valuable insights for the development of Mhp subunit vaccines.

Oral Bacillus subtilis spores-based vaccine for mass vaccination against porcine reproductive and respiratory syndrome.

Porcine reproductive and respiratory syndrome (PRRS) poses a significant challenge in the global swine industry, leading to substantial economic losses and reproductive and respiratory complications. The causative agent, PRRS virus (PRRSV), with its high mutation rate, complicates the development of universally effective vaccines. Furthermore, current PRRS vaccines are limited by high costs and complex administration methods. Therefore, in this study, we aimed to develop an innovative Bacillus subtilis spore-based oral vaccine targeting PRRS. Their oral administration was evaluated in mice and pigs, and blood, saliva, feces, and bronchoalveolar lavage fluid samples were collected for further analyses. Our vaccine induced IgG and IgA immune responses in both models, with swine demonstrating considerable increase in specific antibody and cytokine levels. These results indicate a high potential for more effective and economically viable control of PRRS in commercial pig farming. The ease of administration and cost-effectiveness of the vaccine also offer a feasible option for widespread application. Our results suggest a new direction in veterinary vaccine development, underscoring the potential of B. subtilis spores in creating effective vaccines for large-scale, real-world applications in animal health management.

The association of Helicobacter pylori with adverse pregnancy outcomes in three European birth cohorts.

Helicobacter pylori is a prevalent infection that may complicate pregnancy, but evidence remains limited, controversial and may not apply to all pregnant women. This study aims to evaluate whether Helicobacter pylori is a risk factor for adverse pregnancy outcomes and to identify vulnerable subpopulations. Multiplex serology was utilized to measure blood levels of immunoglobulin G against eight Helicobacter pylori antigens in 1372 pregnant women from three European birth cohorts: BiB (United Kingdom), Rhea (Greece) and INMA (Spain). Outcomes of interest included gestational diabetes mellitus, gestational hypertension, preeclampsia, preterm birth and small for gestational age neonates, as well as prenatal anxiety and depression. Adjusted logistic regression models were used to evaluate the association between Helicobacter pylori seropositivity (overall and by antigen) and antigen specific antibody levels with the outcomes. We examined effect modification of the associations by ethnicity. Helicobacter pylori seropositivity was detected in 18.8% (258/1372) of pregnant women. Preeclampsia was the least common outcome (26/830). Helicobacter pylori seropositivity was associated with the development of two or more adverse pregnancy outcomes (gestational hypertension, gestational diabetes, preterm birth, small gestational age and preeclampsia) [OR:1.32 (95% CI: 1.06-1.65), p-value: 0.01], especially in women with high antibody levels to OMP antigen [OR: 2.12 (95% CI: 1.62-2.76), p-value: 0.001]. Women with high antibody levels to Helicobacter pylori antigens GroEL and NapA were more likely to develop preeclampsia [OR: 2.34 (95% CI: 1.10-8.82), p-value: 0.03; OR: 4.09 (95% CI: 1.4-11.93), p-value 0.01)]. Helicobacter pylori seropositivity increased the odds of developing any hypertensive disorder during pregnancy among women of western ethnicity (948/1372) [OR:3.35 (95% CI: 1.29-8.74), p-value 0.03]. Our study suggests that Helicobacter pylori seropositivity is a risk factor for multiple adverse pregnancy outcomes and particularly in women of western origin for hypertensive disorders during pregnancy. Moreover, pathogen specific characteristics reflected in the antibody responses against OMP, GroEL and NapA seem to determine disease associations.

Immunological quality of colostrum and specific antibodies against enteropathogens in the colostrum and transition milk of crossbred Gir × Holstein cows.

Colostrum management is crucial for enhancing the immune response against enteropathogens and the survival of dairy calves during the first few weeks of life. However, few physiological studies have investigated the dynamics of general and specific immunoglobulin G (IgG) content in cow milk during early lactation stages, particularly in that of crossbred Gir × Holstein dairy cows, the most predominant dairy cattle population in tropical countries, such as Brazil. Therefore, this study evaluated the effects of parity and milking order on the volume and quality of colostrum, transition milk, and mature milk in crossbred Gir × Holstein cows using three traditional on-farm tests. The dynamics of IgG in the mammary secretions and the specific antibody levels against enteropathogens were also determined using sandwich enzyme-linked immunosorbent assay (ELISA) during the early stages of lactation. Fifty healthy Gir × Holstein cows were divided into two groups based on parity number, i.e., primiparous (n = 18) and multiparous (n = 33). They were monitored from the first to the 43rd milking. The colostrum volume and quality were evaluated using a colostrometer, Brix refractometer, and Colostro Balls after the first milking, in addition to the colostral IgG levels measured using sandwich ELISA as a reference standard. On-farm tests showed that the colostrum samples obtained from Gir × Holstein cows exhibited an optimal colostrum quality based on the literature criteria, regardless of parity number; however, the IgG mass was higher in the colostrum of multiparous (201 ± 67.03g) cows than in that of primiparous (144 ± 32.40g) cows. The volume and composition of transition and whole milk were also assessed at the second to ninth, 11th, 13th, 15th, 29th, and 43rd milkings. Multiparous cows produced higher volumes of transition milk than primiparous cows. In addition, multiparous cows exhibited a higher total solids percentage in their postpartum mammary secretions than primiparous cows. A higher percentage of inhibition of specific antibodies against Escherichia coli K99 was observed in the blood serum of multiparous cows than in that of primiparous cows. The volume and composition of mammary secretions changed over time; milk production increased, whereas total solids, total IgG, and specific antibody levels against most enteropathogens decreased, regardless of parity. Additionally, an association between parity and time was observed with respect to milk yield, the Brix score (%), and specific antibody levels against the Clostridium perfringens alpha toxin in mammary sections and against coronavirus and rotavirus in blood samples. This association indicated higher values in multiparous cattle than in primiparous cattle at specific time points. In conclusion, this study reveals postpartum time-dependent changes in the physiological and immunological components in the mammary secretions and blood of crossbred Gir × Holstein cows from the first to the 43rd milking. These results will contribute to the development of future research in Gir × Holstein-specific neonatology, which is genetically adapted to tropical and subtropical countries.

Effect of the MONTANIDE™ IMS 1312 adjuvant on the innate and adaptive immune responses of Nile tilapia (Oreochromis niloticus) against Streptococcusagalactiae through immersion vaccination

Streptococcus agalactiae is a common pathogenic bacterium caused of streptococcosis, which has a negative impact on Nile tilapia aquaculture. Numerous vaccines have been developed recently to combat this disease, which are key components of global health efforts to prevent disease outbreaks. MONTANIDE™ IMS 1312 is a micro-emulsion recommended for immersion of fish. However, the data on the effectiveness of those immersion vaccines containing this aqueous adjuvant in fish are limited. The objective of this research was to explore the potential of MONTANIDE™ IMS 1312, an adjuvant for immersion vaccination, administered with an S. agalactiae inactivated whole-cell vaccine (SAIV) in Nile tilapia. Fish were separated into three groups: 1) fish were vaccinated by immersion vaccination with PBS (CTRL), 2) fish were vaccinated by immersion vaccination with SAIV vaccine alone (SAIV), and 3) fish were vaccinated by immersion vaccination with SAIV containing MONTANIDE™ IMS 1312. We found that the activity of several innate immunity parameters was increased significantly (P < 0.05) following the immunization. As expected, the levels of specific IgM antibody were significantly increased post-vaccination, and the highest IgM antibody levels were found in the fish vaccinated with SAIV containing MONTANIDE™ IMS 1312. Analysis of the transcriptional expression of major pro-inflammatory cytokines, as well as the presence of IgM+ B cells, revealed significant increases, suggesting that Nile tilapia were able to initiate cellular immune responses following vaccination. Taken together, our results indicate that using MONTANIDE™ IMS 1312 in combination with a SAIV can induce strong protection post S. agalactiae infection. Importantly, administration of an adjuvanted immersion vaccine is safe, no side effects were observed, and it does not negatively impact fish growth. In conclusion, MONTANIDE™ IMS 1312 has the potential to be used as adjuvants for immersion vaccines against streptococcosis in Nile tilapia.

Diagnostic Accuracy of Saliva-based Testing as a Vibrio Cholerae Surveillance Tool among naturally-infected patients.

Saliva, as a diagnostic medium, offers a promising alternative to blood by virtue of its non-invasive collection, which enhances patient compliance, especially in paediatric and geriatric populations. In this study, we assessed the utility of saliva as a non-invasive medium for measuring V. cholerae-specific serum antibodies in naturally infected individuals. We tested paired serum and saliva samples obtained from a total of 63 cholera patients enrolled in a cohort study. Vibriocidal antibodies assay (IgM/IgG) as markers for accurate determination was used to determine cholera specific antibody levels. Using receiver operating characteristics (ROC) curve, we found that the best cut-off that maximizes (sensitivity + specificity) is 10 titres. At this saliva titre, the sensitivity is 76.9% (95%CI: 60.9%, 87.7%) and specificity is 80.0% (95%CI: 56.6%, 92.5%). Using Spearman's correlation coefficient, we also found evidence of a positive correlation between Vibrio Cholerae saliva and serum antibodies (rho=0.66, p<0.001). In conclusion, saliva-based diagnostic cholera tests has high diagnostic accuracy, and would be advantageous, cheaper, and quicker for early diagnosis of severe cholera outcomes.

Preliminary evaluation of the protective effect of rEi-SAG19 on Eimeria intestinalis infection in rabbits

Eimeria intestinalis is one of the most pathogenic coccidia species in rabbits. Anticoccidial treaments are the main measures to control rabbit coccidiosis now, but there are drug resistance and residues concerns. Therefore, vaccine has been used as an alternative strategy. The surface antigens (SAGs) of apicomplexan protozoa play a role in adhesion and invasion of host intestinal cells, and are considered to be potential candidate antigens for vaccines. In this study, transcriptional analysis of 5 Ei-SAGs genes at four developmental stages was conducted, then the Ei-SAG19 gene were screened out for prokaryotic expression and the reactogenicity of recombinant SAG19 (rEi-SAG19) was investigated by immunoblotting. To assessment the protective effects of rEi-SAG19, rabbits (n = 40) were randomly divided into four groups (Blank control, PBS-infected, Trx-His-S-Quil-A-infected and rEi-SAG19 immunized groups), the rEi-SAG19 immunized group was subcutaneously immunized with 100 μg rEi-SAG19 in the neck with an interval of two weeks, and challenged with 5×104 homologous oocysts two weeks after the second immunization. Two weeks after the challenge, all rabbits were sacrificed. After that, the level of serum specific IgG antibody was detected weekly and the level of cytokines in serum before the challenge were determined. At the end of the experiment, the weight gain, oocyst reduction rate, lesion score and anticoccidial index (ACI) were calculated. The results showed that rEi-SAG19 has a good reactogenicity. The relative weight gain rate, oocyst reduction rate and ACI of the rabbits in rEi-SAG19 immunized group were 80.51%, 72.6%, and 165.1, respectively, which has a moderate protective effect. The level of serum specific IgG antibody and IL-4 rised significantly (P < 0.05), but the levels of IL-2, IFN-γ and IL-10 had no significant difference (P > 0.05). Our results indicated that rEi-SAG19 could provides moderate protective effect against E. intestinalis infection in rabbits (ACI = 165.1). Therefore, rEi-SAG19 could be used as a vaccine candidate antigen for E. intestinalis.

Intranasal immunization with poly I:C and CpG ODN adjuvants enhances the protective efficacy against Helicobacter pylori infection in mice

Helicobacter pylori (H. pylori) infection is a serious public health issue, and development of vaccines is a desirable preventive strategy for H. pylori. Toll-like receptor (TLR) ligands have shown potential as vaccine adjuvants that induce immune responses, but polyinosinic-polycytidylic acid (poly I:C), a nucleic acid-based TLR9 ligand, is less well studied in H. pylori vaccine research. Here, we evaluated the effects of poly I:C and CpG oligodeoxynucleotide (CpG ODN), a nucleic acid TLR3 ligand, as adjuvants in combination with the H. pylori recombinant proteins LpoB and UreA to protect against H. pylori infection. For analysis of specific immune responses, the levels of specific antibodies and splenic cytokines were measured in the immunized mice. Compared with CpG ODN, poly I:C could induce mucosal sIgA antibody responses and reduce H. pylori colonization. Additionally, the combination of poly I:C and CpG ODN caused greater immunoprotection and significantly reduced gastritis, exerting synergistic effects. Analysis of splenic cytokines revealed that poly I:C mainly triggered a mixed Th1/Th2/Th17 immune response, whereas the combination of CpG ODN and poly I:C induced a Th1/Th17 immune response. Our findings indicated that increased levels of mucosal sIgA antibodies and a robust splenic Th1/Th17 immune response were associated with reduced H. pylori colonization in vaccinated mice. This study identified a potential TLR ligand adjuvant for developing more effective H. pylori vaccines.

A new multi-epitope DNA vaccine against Helicobacter Pylori infection in a BALB/c mouse model

BackgroundHelicobacter Pylori (H. Pylori) is a pathogen that may invade the human stomach. This bacterial strain is now causing widespread concern and considerable health issues worldwide. In contrast to antibiotic treatment, which may lead to drug resistance, vaccination therapy is emerging as a possible immunotherapy option for H. Pylori. DNA vaccines are a potential option to traditional vaccines among vaccine research methods. Furthermore, the multiepitope DNA vaccination may induce a broader immune response to suppress H. Pylori infection. MethodsFour target antigenic proteins (outer membrane beta-barrel, outer membrane beta, HofA, and hcp beta-lactamase-like protein) were used to identify epitopes. The best B and T cell epitopes were selected to induce humoral and cellular immune responses and were connected using the HEYGAEALERAG and GGGS linkers. The peptide's physicochemical characteristics, secondary and tertiary structures, antigenicity, and allergenicity were evaluated utilizing several bioinformatics tools. The multiepitope peptide was successfully inserted into the pcDNA3.1 expression vector. The immunological responses of both the vaccinated and control groups were evaluated by measuring cytokines and antibodies. ResultsBased on the data, the multiepitope peptide consists of 278 amino acid residues and has an average molecular weight (MW) of 28643.61 Da. The peptide residues were mainly situated within the preferred and permitted areas of the Ramachandran plot, accounting for 92.86% of the total. The VaxiJen server has calculated that the multiepitope peptide has an antigenicity score of 1.0067. BALB/c mice vaccinated with the DNA vaccine produced significantly higher levels of specific IgG antibodies (p<0.05). The vaccinated mice exhibited a TH1-type cellular immune response characterized by the generation of IFN-γ and a longer length of life compared to the control animals (p<0.05). In addition, the vaccination group exhibited a substantial increase in the expression level of IFN-γ and IL-1β genes compared to the control group (p<0.05). ConclusionsThe results demonstrated that the multiepitope DNA vaccine elicited significant humoral and cellular responses, and increased survival time in BALB/c mice, indicating that selecting potential epitopes may be a viable technique for developing multiepitope-based vaccines. This can help to introduce effective vaccines.

Comparison of urine and serum IgG detection ELISA for tegumentary leishmaniasis diagnosis and prognosis

Laboratorial diagnosis of tegumentary leishmaniasis (TL) is hampered by variable sensitivity and/or specificity of the tests, which are still hampered by blood́ invasive collection. In this context, in the present study, we develop a serum- and urine-based ELISA to TL diagnoses. A recombinant protein (rLiHyA), which was previously showed to be antigenic for the disease, as well as a B-cell epitope produced as synthetic peptide and a Leishmania antigenic extract (SLA), were used as antigens. A total of paired 205 urine and serum samples were used, which were comprised by samples from cutaneous (n = 30) and mucosal (n = 30) leishmaniasis patients, as well as from healthy individuals living in endemic region of disease (n = 45), of patients with Chagas disease (n = 30), leprosy (n = 35), malaria (n = 15) or HIV-infected (n = 20). Results showed that serum-based ELISA presented sensitivity of 24.0 %, 100 % and 41.0 %, when SLA, rLiHyA and synthetic peptide were used as antigens, and specificity of 98.4 %, 98.4 % and 98.4 %, respectively. The area under the curve (AUC) was calculated and results were 0.74, 1.0, and 0.71, respectively, when SLA, rLiHyA and synthetic peptide were used as antigens. Performing an urine-based ELISA, sensitivity was 28.0 %, 100 % and 75.0 %, respectively, when SLA, rLiHyA, and synthetic peptide were used, while specificity values were of 98.4 %, 98.4 % and 98.4 %, respectively. In addition, the AUC values were 0.82, 1.0, and 0.94, respectively. A significant drop in specific antibodies levels in both patientś serum and urine samples was found six months after treatment, suggesting a prognostic role of rLiHyA for TL. In conclusion, preliminary data suggest the potential of use patient urine to TL diagnoses.

Q Fever in Greece and Factors of Exposure: A Multiregional Seroprevalence Study.

The epidemiology of Q fever, caused by Coxiella burnetii, varies significantly worldwide. This study aimed to document the prevalence of Coxiella burnetii in Greece by measuring specific IgG antibody levels in serum samples from the general population and high-risk groups, including farmers, veterinarians, and laboratory workers. A multiregional, stratified sampling design was employed, with 1,345 participants from Thessaly and Central Macedonia. Serum samples were tested for Coxiella burnetii IgG antibodies, and multivariate analysis was conducted to identify factors associated with seroprevalence. Overall, 8.1% of participants tested positive for Coxiella burnetii antibodies, with the highest seroprevalence in Larissa (22.2%) and Karditsa (16.1%). High-risk occupational groups, particularly those with direct animal contact, showed a higher seroprevalence (13.6%). Multivariate analysis identified significant associations between seroprevalence and factors such as geographic region, occupation, and gender. The study reveals regional and occupational disparities in Q fever seroprevalence in Greece, particularly in rural areas. These findings underscore the need for targeted public health measures, including heightened surveillance and preventive interventions for high-risk groups.

Ferritin nanoparticle-based Nipah virus glycoprotein vaccines elicit potent protective immune responses in mice and hamsters

Nipah virus (NiV) is a zoonotic paramyxovirus in the genus Henipavirus that is prevalent in Southeast Asia. NiV leads to severe respiratory disease and encephalitis in humans and animals, with a mortality rate of up to 75%. Despite the grave threat to public health and global biosecurity, no medical countermeasures are available for humans. Here, based on self-assembled ferritin nanoparticles (FeNPs), we successfully constructed two candidate FeNP vaccines by loading mammalian cells expressing NiV sG (residues 71–602, FeNP-sG) and Ghead (residues 182–602, FeNP-Ghead) onto E. coli-expressed FeNPs (FeNP-sG and FeNP-Ghead, respectively) through Spycatcher/Spytag technology. Compared with sG and Ghead alone, FeNP-sG and FeNP-Ghead elicited significant NiV specific neutralizing antibody levels and T-cell responses in mice, whereas the immune response in the FeNP-sG immunized group was greater than that in the FeNP-Ghead group. These results further demonstrate that sG possesses greater antigenicity than Ghead and that FeNPs can dramatically enhance immunogenicity. Furthermore, FeNP-sG provided 100% protection against NiV challenge in a hamster model when it was administered twice at a dose of 5 μg/per animal. Our study provides not only a promising candidate vaccine against NiV, but also a theoretical foundation for the design of a NiV immunogen for the development of novel strategies against NiV infection.

Assessment of health impacts in retired antisera-producing horses: Blood biochemistry and serum amyloid A analysis.

Horses used for antisera production are repeatedly hyperimmunized to produce high levels of specific antibodies. This prolonged process can lead to various health issues, including amyloidosis, which involves the accumulation of amyloid proteins in organs and tissues, potentially causing organ dysfunction and failure. These horses are often retired when they no longer produce adequate antibody levels. This study aimed to evaluate the impact of prolonged antisera production on the health of retired horses by examining their blood biochemistry and serum amyloid A (SAA) levels, which are indicators of systemic inflammation and organ damage. Blood samples were collected from 12 horses for this study. Nine horses were retired antisera-producing horses that had been discontinued for 2 years, while three healthy non-antisera-producing horses were used as controls. These twelve horses were divided into four groups based on the duration of their active period as antisera producers (never been used, 2-3 years, 4-5 years, and 6-7 years). We measured key blood biochemistry parameters and SAA levels to evaluate the health status of the horses. Total protein, fibrinogen, and globulin levels were elevated, whereas other parameters remained normal. The findings indicate that despite normal SAA levels, the horses exhibited signs of ongoing health issues related to their previous use in antisera production, such as increased total plasma protein, fibrinogen, and globulin levels, as well as the presence of amyloid deposits in vital organs such as the liver and kidneys, as observed in post-mortem examinations. Despite normal SAA levels, retired antisera-producing horses showed elevated total protein, fibrinogen, and globulin levels, indicating ongoing health issues.

Association between asthma and IgG levels specific for rhinovirus and respiratory syncytial virus antigens in children and adults

BackgroundViral infections in childhood, especially to rhinovirus (RV) and respiratory syncytial virus (RSV) are associated with asthma inception and exacerbation. However, little is known about the role of RV- and RSV-specific antibodies in childhood versus adult asthma. ObjectiveTo investigate associations between RV- and RSV-specific IgG levels with asthma phenotypes, in children and adults. MethodsThe analysis included 1771 samples from 1501 participants of the Epidemiological Study on the Genetics and Environment of Asthma (EGEA) (530 children (mean(sd) age = 11.1 (2.8) and 1241 adults (mean(sd) age = 43.4(16.7), among which 274 and 498 had ever asthma, respectively). RSV- and RV-specific IgG levels were determined using micro-arrayed virus-derived antigens and peptides. Cross-sectional associations between standardized RSV- and RV-specific IgG levels and asthma phenotypes were estimated by multiple regression models. ResultsIn children, ever asthma was associated with higher IgG levels specific to RV, especially to RV-A, RV-C and to RSV (adj-OR for 1-sd increase in IgG levels = 1.52 (95%CI, 1.16;1.99), 1.42 (1.10;1.83) and 1.24 (0.99;1.54), respectively). These associations were stronger for moderate-to-severe asthma than for mild asthma. Conversely in adults, ever asthma was associated with lower RV-A, RV-B and RV-C IgG levels (adjusted OR = 0.86 (0.74;0.99), 0.83 (0.73;0.95) and 0.85 (0.73;0.99), respectively). ConclusionOur results suggest that the association between respiratory virus specific antibody levels and asthma varies during life, with asthma associated with higher levels of IgG to RSV, RV-A and RV-C in children and lower levels of IgG responses to RV-A/B/C in adults.

Seroprevalence of B. pertussis infection and the changes of specific antibody levels in health care workers during the first two years of COVID-19 in Wuhu, China

BackgroundThe reported number of pertussis cases declined after the implementation of COVID-19 prevention and control measures, however, the burden of pertussis among adults in China remains largely unknown. Additionally, the waning of natural antibody level has also rarely been assessed. MethodsA total of 762 healthcare workers (HCWs) who had underwent the health examinations in 2021 and 2022 were included. Serum anti-PT IgG and IgA levels were determined by ELISA. Recent B. pertussis infection was defined as anti-PT IgG ≥100 IU/ml and/or anti-PT IgA ≥10 IU/ml. ResultsIn 2021, the seroprevalence of recent B. pertussis infection was 10.1 %, and those HCWs in outpatient department had a higher percentage (18.6 %), and geometric mean concentration (GMC) (6.3 IU/ml) than those in other departments. This seroprevalence decreased to 2.4 % in 2022, although the difference remained significant. In the 77 subjects with recent B. pertussis infection in 2021, anti-PT IgG was undetectable in 18 cases the following year. Majority (68/76) of the subjects with anti-PT IgA ≥10 IU/ml in 2021 no longer had detected this antibody in 2022. Among 95 pertussis cases, approximately 60.0 % of cases reported no history of cough. Among those with a documented cough history, 36 cases with suspected pertussis courses who had never been diagnosed. Prolonged cough with nocturnal exacerbation (29/38) was the most commonly reported clinical symptom, and whoop was confirmed in six cases. Uroclepsia and syncopes during the cough attacks were reported by three and one subjects, respectively. One case presented with subconjunctival hemorrhage and tensionic purpura during the course. ConclusionsThe results suggested a high prevalence of B. pertussis infection among HCWs. The presence of unrecognized adult pertussis cases and the rapid waning of antibody indicate the need to improve clinical management for suspected pertussis in adults, and to updated immunization schedule after childhood program.

Recombinant outer membrane protein Lipl41 from Leptospira interrogans robust immune responses in mice model.

Leptospirosis is an infectious zoonotic disease that can result in severe complications. It is widespread, especially in hot and humid climates such as the northern region of Iran. The immune responses to leptospirosis are multifaceted. Lipl41 is an outer membrane protein that is expressed during infection and is highly conserved among pathogenic species. This makes it a good candidate for diagnosis and induction of specific immune responses. The aim of the present study was to evaluate immune responses against recombinant Lipl41 in mice. After immunizing of different groups of mice with recombinant Lipl41 (rLipl41), the levels of specific antibodies and cytokine profiles interferon-gamma/interleukin-4 (IFN-γ/IL-4) were measured. The results revealed that rLipl41 showed a significant increase in antibody levels compared with the control groups (P< 0.05). Although the level of IL-4 in the groups that received Lipl41 was similar to that in the other control groups, the IFN-γ levels showed a significant increase (P<0.05). It has been concluded that recombinant Lipl41 protein could strongly stimulate specific immune responses and be considered a potential candidate for vaccine development and diagnostic research.

Virtual crossmatching reveals upregulation of placental HLA-Class II in chronic histiocytic intervillositis

Chronic histiocytic intervillositis (CHI) is a recurrent placental lesion where maternal macrophages infiltrate the intervillous space. Its cause is unknown, though due to similarities to rejected allografts one hypothesis is that CHI represents maternal–fetal rejection. Here, virtual crossmatching was applied to healthy pregnancies and those with a history of CHI. Anti-HLA antibodies, measured by Luminex, were present in slightly more controls than CHI (8/17 (47.1%) vs 5/14 (35.7%)), but there was no significant difference in levels of sensitisation or fetal specific antibodies. Quantification of immunohistochemical staining for HLA-Class II was increased in syncytiotrophoblast of placentas with CHI (Grade 0.44 [IQR 0.1–0.7]) compared to healthy controls (0.06 [IQR 0–0.2]) and subsequent pregnancies (0.13 [IQR 0–0.3]) (P = 0.0004). HLA-Class II expression was positively related both to the severity of CHI (r = 0.67) and C4d deposition (r = 0.48). There was no difference in overall C4d and HLA-Class I immunostaining. Though increased anti-HLA antibodies were not evident in CHI, increased expression of HLA-Class II at the maternal–fetal interface suggests that they may be relevant in its pathogenesis. Further investigation of antibodies immediately after diagnosis is warranted in a larger cohort of CHI cases to better understand the role of HLA in its pathophysiology.

Effects of Acremonium terricola Culture on Lactation Performance, Immune Function, Antioxidant Capacity, and Intestinal Flora of Sows.

This study aimed to determine the effects of different doses of Acremonium terricola culture (ATC) on lactation performance, immune function, antioxidant capacity, and intestinal flora of sows. Forty-five Landrace sows (3-6 parity) were randomly assigned to the following three treatments from 85 days of gestation to 21 days after farrowing: a control diet (CON, basal diet), a low-dose Acremonium terricola culture diet (0.2% ATC, basal diet + 0.2% ATC), and a high-dose Acremonium terricola culture diet (0.4% ATC, basal diet + 0.4% ATC). Compared with the CON group, the supplementation of 0.2% ATC increased the average daily milk yield of sows by 4.98%, increased milk fat, total solids, and freezing point depression on day 1 postpartum (p < 0.05), increased serum concentration of Triiodothyronine, Thyroxin, and Estradiol on day 21 postpartum (p < 0.05). Compared with the CON group, the supplementation of 0.4% ATC increased the average daily milk yield of sows by 9.38% (p < 0.05). Furthermore, the supplementation of 0.2% ATC increased serum concentration of IgG, IgM, and IFN-γ, CD4 on day 1 postpartum (p < 0.05) and increased serum concentration of immunoglobulin A ( IgA), immunoglobulin G (IgG), immunoglobulin M ( IgM), complement 3 (C3), cluster of differentiation 4 (CD4), cluster of differentiation 8 (CD8), interferon-γ (IFN-γ) on day 21 postpartum (p < 0.05), while the supplementation of 0.4% ATC reduced serum concentration of IL-2 on day 21 postpartum (p < 0.05). Moreover, the supplementation of 0.4% ATC significantly increased serum concentration of catalase (CAT) (p < 0.05). Additionally, the supplementation of ATC affected the relative abundance of the intestinal flora at different taxonomic levels in sows and increased the abundance of beneficial bacteria such as in the norank_f__Eubacterium_coprostanoligenes group, Eubacterium_coprostanoligenes group, and Lachnospiraceae_XPB1014 group of sows, while reducing the abundance of harmful bacteria such as Phascolarctobacterium and Clostridium_sensu_stricto_1. These data revealed that the supplementation of ATC during late gestation and lactation can improve lactation performance, immune function, antioxidant capacity, and the gut microbiota. Compared with supplementation of 0.4% ATC, 0.2% ATC enhances the levels of thyroid-related hormones, specific antibodies, and cytokines in serum, promotes the diversity of beneficial gut microbiota, beneficial bacteria in the intestine, reduces the population of harmful bacteria, and thereby bolsters the immunity of sows. Hence, 0.2% ATC is deemed a more optimal concentration.

Generating the Evidence Base for Convalescent Plasma Use for a New Infectious Disease.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) swept across the world in the waning months of 2019 and emerged as the cause of the coronavirus disease 19 (COVID-19) pandemic in early 2020. The use of convalescent plasma (CP) for prior respiratory pandemics provided a strong biological rationale for the rapid deployment of COVID-19 convalescent plasma (CCP) in early 2020 when no validated treatments or prior immunity existed. CCP is an antiviral agent, with its activity against SARS-CoV-2 stemming from specific antibodies elicited by the virus. Early efforts to investigate the efficacy of CCP in randomized clinical trials (RCTs) that targeted hospitalized patients with COVID-19 did not demonstrate the overall efficacy of CCP despite signals of benefit in certain subgroups, such as those treated earlier in disease. In contrast, studies adhering to the principles of antibody therapy in their study design, choice of patient population, and product qualification, i.e., those that administered high levels of specific antibody during the viral phase of disease in immunocompromised or very early in immunocompetent individuals, demonstrated benefits. In this chapter, we leverage the knowledge gained from clinical studies of CCP for COVID-19 to propose a framework for future studies of CP for a new infectious disease. This framework includes obtaining high-quality CP and designing clinical studies that adhere to the principles of antibody therapy to generate a robust evidence base for using CP.

Effects of hydrogen peroxidase-inactivated vaccine against Streptococcus agalactiae infection in red tilapia (Oreochromis sp.) via different routes of administration

Hydrogen peroxidase-inactivated vaccines have recently developed in controlling infectious diseases in aquaculture. The present study aimed to compare the efficacy of the hydrogen peroxidase-inactivated Streptococcus agalactiae vaccine via different delivery routes (injection, immersion, and oral administration) in red tilapia (Oreochromis sp.) without using adjuvant. Fish were randomly divided into 4 groups including G1: Control treatment (without vaccine), G2: vaccine-based diet (oral administration), G3: vaccinated by immersion and G4: vaccinated by injection. After 6 weeks of the experiment, fish were intraperitoneally injected with S. agalactiae and the mortality was recorded in 14 days. The results showed that lysozyme activity was differentially increased according to the delivery routes of vaccine, organs and time of sampling. However, the specific antibody levels in all vaccinated groups were only increased in week 6 post-vaccination. After the challenge test with S. agalactiae, the serum lysozyme levels in G3 and G4 were significantly higher than the control group (G1), while the total white blood cells and specific antibody levels were significantly increased in G2 and G4 compared to the control (G1). Similarly, the hydrogen peroxidase-inactivated vaccine statistically reduced the cumulative mortality in G2 (35.29%) and G4 (28.95%) compared to G1 (44.12%) after injected with the S. agalactiae. These results showed that the vaccine delivery routes by oral administration or injection may decrease the pathogen and show better protection for red tilapia than the immersion method. Further studies will be investigated to improve the efficacy of hydrogen peroxidaseinactivated vaccine via using different adjuvants.