The Novel Fusion Protein Melittin-MIL-2 Exhibits Strong Antitumor Immune Effect in Lung Adenocarcinoma Cell A549.

In previous studies, we developed a novel fusion protein named "melittin-MIL-2" which exhibited more anti-tumor activity. However, it remains unclear whether melittin-MIL-2 possesses antitumor immune effect on lung adenocarcinoma. In this study, the immune effect and mechanism of melittin-MIL-2 inhibiting the growth and invasion of lung adenocarcinoma will be investigated, in order to provide novel perspectives for the immunotherapy of lung cancer. The results indicated that melittin-MIL-2 promoted T cell proliferation, enhanced NK cell cytotoxicity, and boosted IFN-γ secretion in PBMCs. After melittin-MIL-2 stimulation, perforin expression and LAK/NK-like killing activities of human PBMCs and NK cells were significantly enhanced. Melittin-MIL-2 is capable of hampering the development and proliferation of lung adenocarcinoma cell A549. ICAM-1 and Fas expression in A549 cells exposed to melittin-MIL-2 rose significantly. The expression levels of TLR8 and VEGF in A549 cells decreased significantly after melittin-MIL-2 stimulation. In vivo, melittin-MIL-2 substantially impeded the growth of lung adenocarcinoma and formed an immune-stimulating microenvironment locally in tumor tissues. In conclusion, the novel fusion protein melittin-MIL-2 exhibits strong anti-tumor immune effect in lung adenocarcinoma cell A549 via activating the LFA-1/ICAM-1 and Fas/FasL pathways to enhance cytolytic activity, upregulating the secretion of IFN-γ and perforin, and boosting LAK/NK-like killing activities. Immuno-effector cells and their secreted cytokines can form immune stimulation microenvironment locally in lung adenocarcinoma Lewis mice tissue.

Expression of VP2 protein of Novel goose parvovirus in baculovirus and evaluation of its immune effect.

Short-beak and dwarfism syndrome (SBDS) is a new disease caused by a genetic variant of goose parvovirus in ducks that results in enormous economic losses for the waterfowl industry. Currently, there is no commercial vaccine for this disease, so it is urgent to develop a safer and more effective vaccine to prevent this disease. In this study, we optimized the production conditions to enhance the expression of the recombinant VP2 protein and identified the optimal conditions for subsequent large-scale expression. Furthermore, the protein underwent purification via nickel column affinity chromatography, followed by concentration using ultrafiltration tube. Subsequently, it was observed by transmission electron microscopy (TEM) that the NGPV recombinant VP2 protein assembled into virus-like particles (VLPs) resembling those of the original virus. Finally, the ISA 78-VG adjuvant was mixed with the NGPV-VP2 VLPs to be prepared as a subunit vaccine. Furthermore, both agar gel precipitation test (AGP) and serum neutralization test demonstrated that NGPV VLP subunit vaccine could induce the increase of NGPV antibody in breeding ducks. The ducklings were also challenged with the NGPV, and the results showed that the maternal antibody level could provide sufficient protection to the ducklings. These results indicated that the use of the NGPV VLP subunit vaccine based on the baculovirus expression system could facilitate the large-scale development of a reliable vaccine in the future.

Investigation on the immune effect of a chitosan-based particle-in-oil-in-water emulsion.

Particle-in-oil-in-water (P/O/W) multiple emulsion adjuvants introduce particles into the internal water phase of a water-in-oil-in-water emulsion, combining the advantages of both particle and emulsion adjuvants to enhance humoral and cellular immune responses. In this study, we optimized P/O/W multiple emulsion adjuvants. Chitosan, poly (lactic-co-glycolic acid), and aluminum gel were used to prepare the particles, which were introduced into a water-in-oil-in-water emulsion to obtain three P/O/W multiple emulsion adjuvants. The immune enhancement effects and safety of the three adjuvants were compared, and it was proven that the adjuvant with chitosan nanoparticles in the internal water phase had good cellular and humoral immune effects. Simultaneously, the proportion of the internal water phase increased from 13% to 20%, reducing the antigen concentration required for embedding to one-third of the original concentration and expanding the application range of the composite adjuvant.

Immune Effects of Cryoablation in Woodchuck Hepatocellular Carcinoma.

Objectives: Local and systemic immune responses evoked by locoregional therapies such as cryoablation are incompletely understood. The aim of this study was to characterize cryoablation-related immune response and the capacity of immune drugs to augment immunity upon cryoablation for the treatment of hepatocellular carcinoma (HCC) using a woodchuck hepatocellular carcinoma model. Materials and Methods: Twelve woodchucks chronically infected with woodchuck hepatitis virus and with hepatocellular carcinoma underwent imaging with contrast-enhanced CT. Partial cryoablation of tumors in three woodchucks was performed. Fourteen days after cryoablation, liver tissues were harvested and stained with H&E and TUNEL, and immune infiltrates were quantified. Peripheral blood mononuclear cells (PBMC) were collected from ablated and nonablated woodchucks, labeled with carboxyfluorescein succinimidyl ester (CFSE) and cultured with immune-modulating drugs, including a small PD-L1 antagonist molecule (BMS-202) and three TLR7/8 agonists (DSR 6434, GS-9620, gardiquimod). After incubation, cell replication and immune cell populations were analyzed by flow cytometry. Results: Local immune response in tumors was characterized by an increased number of CD3+ T lymphocytes and natural killer cells in the cryolesion margin compared to other tumor regions. T regulatory cells were found in higher numbers in distant tumors within the liver compared to untreated or control tumors. Cryoablation also augmented the systemic immune response as demonstrated by higher numbers of PBMC responses upon immune drug stimulation in the cryoablation group. Conclusions: Partial cryoablation augmented immune effects in both treated and remote untreated tumor microenvironments, as well as systemically, in woodchucks with HCC. Characterization of these mechanisms may enhance development of novel drug-device combinations for treatment of HCC.

Ultra-efficient radio-immunotherapy for reprogramming the hypoxic and immunosuppressive tumor microenvironment with durable innate immune memory.

Radiosensitization efficacy of conventional tumor radiosensitizers has been frequently limited by insufficient competence for tumor microenvironment (TME) regulation and unfavorable cellular uptake at biological barriers. Here, we reported an ultra-efficient radiotherapy (RT) strategy by synthesizing an extracellular vesicles (EVs)-encapsulated hollow MnO2 to load metformin (Met@HMnER). It demonstrated significant RT enhancement by morphological control of catalyst and cellular respiratory depression against conventional solid MnO2. Furthermore, the target-modified EVs clothing retains outstanding metformin loading capacity while endowing enhanced biological barrier penetration. A noticeably durable innate immune activation of NK cells was triggered with this nanoplatform via the cGAS-STING pathway. The enhanced immunocompetence was verified on distal metastasis and in-situ recurrence model in vivo, This work paved a new path for synergistic and robust innate immunity in clinical cancer treatment.

The antimicrobial peptide MetchnikowinII enhances Ptfa antigen immune responses against avian Pasteurella multocida in chickens.

Immunostimulants and vaccines are the main means for controlling infectious diseases and searching highly effective and low toxic immunestimulants has always been the focus of researchers. The MetchnikowinII (MetII) had been expressed by us and exhibited both antibacterial and antifungal activities, in this study, we evaluated its potential for an adjuvant effect. In chickens, antigen-specific immunoglobulin Gs (IgGs) were increased after MetII adjuvanted vaccination using the Ptfa protein. Compared to group Ptfa + iFA, which was only adjuvanted with incomplete Freund's adjuvant (iFA), the antibody titers of the group Ptfa + iFA + Met20 µg·mL-1 (PFM20) and Ptfa + iFA + Propolis (PFP) significantly increased (P<0.05). Likewise, Interleukin-2 (IL-2) and Interferon-γ (IFN-γ) cytokines in group Ptfa + iFA + Met20 µg·mL-1 (PFM20) and Ptfa + iFA + Propolis (PFP) were significantly higher than those of the other three experimental groups (P<0.05). The stimulation index (SI) value in chickens of group PFM20 was significantly higher than that of the other four experimental groups (P<0.05). Chickens that received MetII adjuvanted vaccinations benefitted from higher protection rate (88%) when challenged with Pasteurella multocida (P. multocida), which was significantly higher than those of group PF and PFP (P<0.05). These results suggested that the antimicrobial peptide MetII may play an adjuvant role in the immune response in chickens but need a proper usage, because the higher usage of 40 µg·mL-1 and 60 µg·mL-1 resulted poor effect. Whether MetII could be a potential adjuvant or a biomolecule as part of a complex adjuvant for vaccines needs more experimental evidence, the study still provides an examples for understanding vaccine adjuvants.

A novel miRNA, Cse-miR-33, functions as an immune regulator by targeting CsTRAF6 in Chinese tongue sole (Cynoglossus semilaevis).

The tumor necrosis factor receptor-associated factor 6 (TRAF6) can act as a fundamental adaptor protein in a chain reaction of signal transduction and cascade events to finish off immune defenses. However, immunomodulatory research on TRAF6 gene is still limited in fish. In this study, a novel miRNA, Cse-miR-33 was identified from the whole genome of Chinese tongue sole (Cynoglossus semilaevis). After separate infections with three different Vibrio strains (V. harveyi, V. anguillarum, V. parahemolyticus) and one virus (nervous necrosis virus, NNV), the expressions of CsTRAF6 and Cse-miR-33 displayed significant time-dependent changes in immune related tissues and the trends were opposite in general. Through target gene prediction and dual luciferase reporter assay, Cse-miR-33 was proven to regulate CsTRAF6 by combining with 3'-UTR sequence of the gene. The results of qRT-PCR and western blotting (WB) analyses showed that Cse-miR-33 blocked the translation of CsTRAF6 protein at post-transcriptional level, rather than degrading the target mRNA. Further experiment indicated that Cse-miR-33 inhibitor largely reduced the death rate of Chinese tongue sole caused by V. harveyi and NNV. The expressions of CsTRAF6-associated immune genes (such as CsIL-1R, CsMYD88, CsIRAK1, CsTNFα, CsIL6 and CsIL8) were also significantly changed in response to Cse-miR-33 agomir and inhibitor. The study suggested that Cse-miR-33 affected the immune response via targeting CsTRAF6 in C. semilaevis, which would provide us deep insights into miRNA-mediated regulatory network and help improve the immunity in fish.

Mechanism of TLR4 mediated immune effect in transfusion-induced acute lung injury based on Slit2/Robo4 signaling pathway.

BACKGROUND: Transfusion-related acute lung injury (TRALI) is the infusion of blood or blood system. OBJECTIVE: To explore the mechanism of TLR4-mediated T cell immune effect in TRALI. METHODS: In this animal study, a mouse model of LPS-induced TRALI was established. Sixty adult C57/BL6 mice (wild-type, WT) were randomly divided into 5 groups: 1) normal WT type, 2) LPS control group of WT type lipopolysaccharide, 3) WT type TRALI group (LPS + MHC-I mAb), 4) (TLR4 antibody) lipopolysaccharide LPS control group, 5) (TLR4 antibody) TRALI group (LPS + MHC-I mAb). Mice were injected with LPS (0.1 mg/kg) and MHC-I mAb (2 mg/kg) into the tail vein. H&E staining was performed to detect pathological features. The myeloperoxidase (MPO) activity and the level of inflammatory cytokines in lung tissue homogenate supernatant were measured. Blood, spleen single-cell suspension, and bronchoalveolar lavage fluid were collected to detect the ratio of Treg and Th17 cells by flow cytometry. RT-PCR and WB were used to detect mRNA or protein expression. RESULTS: TLR4 mAb treatment alleviated the pathogenesis of LPS-induced TRALI in vivo, the MPO activity, and the level of proinflammatory factors in lung tissues. TLR4 exerted its function by changing of Treg/Th17 ratio via the SLIT2/ROBO4 signaling pathway and downregulating CDH5 and SETSIP. CONCLUSION: TLR4 mediates immune response in the LPS-induced TRALI model through the SLIT2/ROBO4 signaling pathway.

Evaluation of immune effect of diphtheria toxoid vaccine with chitosan as adjuvant on mice / 中国生物制品学杂志

@#Objective To evaluate the immune effect of the diphtheria toxoid(DT)vaccine using chitosan as adjuvant on mice,so as to provide an experimental basis for the preparation of novel adjuvant vaccines of DT.Methods A total of 30 male C57BL/6 mice were divided into mucosal immunization group and humoral immunization group,and each group was randomly divided into 6 groups:negative control group(PBS),positive control group(DT),aluminum adjuvant group,chitosan adjuvant group(final solution with 0.5% chitosan),aluminum adjuvant vaccine group and chitosan adjuvant vaccine group,with 5 mice in each group. Mucosal immunization group and humoral immunization group were inoculated with 500 μL PBS buffer,10 μg DT,500 μg aluminum adjuvant and 500 μL chitosan adjuvant per mouse by nasal drip and intraperitoneal injection respectively. The mice were observed for the status,collected for the eyeball serum before inoculation(0 d)and 7,21,35 d after inoculation,and collected for the nasal lotion simultaneously. The levels of IgG antibody in serum and sIgA antibody in nasal lotion were detected by ELISA.Results After intraperitoneal injection and nasal drip of chitosan adjuvant vaccine,the mental and behavioral state of mice was normal. Chitosan adjuvant vaccine effectively induced the IgG antibody against diphtheria in mice with not significant difference,compared with the classic aluminum adjuvant vaccine group(F = 127.926 > F_(0.05(1,8)),P > 0.05);It also induced the production of sIgA in mice,which was significantly higher than that in the classical aluminum adjuvant vaccine group 21 d after immunization(F =127.926 > F_(0.05(1,8)),P < 0.05).Conclusion Chitosan adjuvant DT vaccine can effectively stimulate the mucosal immunity and humoral immunity in mice with good safety,and has the potential to be an alternative to aluminum adjuvant for vaccine preparation,which can be considered as nasal drop vaccines.

Corrigendum: A potential bioelectromagnetic method to slow down the progression and prevent the development of ultimate pulmonary fibrosis by COVID-19.

[This corrects the article DOI: 10.3389/fimmu.2020.556335.].

Screening the potential part of the G protein antigen is an achievable strategy to improve the immune effect of DNA vaccine against MSRV infection.

DNA vaccines, as an effective prophylactic technology to induce both humoral and cellular immune responses, have already been widely studied to prevent and control viral and bacterial infections in aquaculture. To find a more effective and safer way to control Micropterus salmoides rhabdovirus (MSRV) infection in largemouth bass, two different DNA vaccines expressing partial (pcDNA3.1-G2) and full-length (pcDNA3.1-G) of the MSRV G protein were developed and injected intramuscularly with different doses. The immune effect was comprehensively compared and evaluated by detecting immune-related parameters including serum antibody levels, immune-related physiological indexes, immune-related gene expression and relative survival rates in this study. The results showed that compared with the pcDNA3.1-G vaccine, the pcDNA3.1-G2 vaccine induced higher serum antibody levels, a lower nonspecific immune response in serum (ACP, SOD and T-AOC activities), higher immune-related gene expression and a higher relative survival rate. Moreover, the immune effect of pcDNA3.1-G2-vaccinated fish showed gradually higher with the increasing pcDNA3.1-G2 concentration, especially in pcDNA3.1-G2 (10µg/per fish) group, the relative survival rate reached to 82.5%, which was significant higher (p < 0.05) than pcDNA3.1-G (10µg/per fish) group. This study indicated that screening the potential core part of an antigen is an achievable strategy to improve the immunogenicity and immunoprotective effect of DNA vaccine.

Research progress of bile biomarkers and their immunoregulatory role in biliary tract cancers.

Biliary tract cancers (BTCs), including cholangiocarcinoma and gallbladder carcinoma, originate from the biliary epithelium and have a poor prognosis. Surgery is the only choice for cure in the early stage of disease. However, most patients are diagnosed in the advanced stage and lose the chance for surgery. Early diagnosis could significantly improve the prognosis of patients. Bile has complex components and is in direct contact with biliary tract tumors. Bile components are closely related to the occurrence and development of biliary tract tumors and may be applied as biomarkers for BTCs. Meanwhile, arising evidence has confirmed the immunoregulatory role of bile components. In this review, we aim to summarize and discuss the relationship between bile components and biliary tract cancers and their ability as biomarkers for BTCs, highlighting the role of bile components in regulating immune response, and their promising application prospects.

Bioinformatics-based SARS-CoV-2 epitopes design and the impact of spike protein mutants on epitope humoral immunities.

BACKGROUND: Epitope selection is the key to peptide vaccines development. Bioinformatics tools can efficiently improve the screening of antigenic epitopes and help to choose the right ones. OBJECTIVE: To predict, synthesize and testify peptide epitopes at spike protein, assess the effect of mutations on epitope humoral immunity, thus provide clues for the design and development of epitope peptide vaccines against SARS-CoV-2. METHODS: Bioinformatics servers and immunological tools were used to identify the helper T lymphocyte, cytotoxic T lymphocyte, and linear B lymphocyte epitopes on the S protein of SARS-CoV-2. Physicochemical properties of candidate epitopes were analyzed using IEDB, VaxiJen, and AllerTOP online software. Three candidate epitopes were synthesized and their antigenic responses were evaluated by binding antibody detection. RESULTS: A total of 20 antigenic, non-toxic and non-allergenic candidate epitopes were identified from 1502 epitopes, including 6 helper T-cell epitopes, 13 cytotoxic T-cell epitopes, and 1 linear B cell epitope. After immunization with antigen containing candidate epitopes S206-221, S403-425, and S1157-1170 in rabbits, the binding titers of serum antibody to the corresponding peptide, S protein, receptor-binding domain protein were (415044, 2582, 209.3), (852819, 45238, 457767) and (357897, 10528, 13.79), respectively. The binding titers to Omicron S protein were 642, 12,878 and 7750, respectively, showing that N211L, DEL212 and K417N mutations cause the reduction of the antibody binding activity. CONCLUSIONS: Bioinformatic methods are effective in peptide epitopes design. Certain mutations of the Omicron would lead to the loss of antibody affinity to Omicron S protein.

Recombinant Listeria ivanovii strain expressing listeriolysin O in place of ivanolysin O might be a potential antigen carrier for vaccine construction.

Listeria monocytogenes (LM) induces efficient and specific T-cell immune responses in the host. Listeriolysin O (LLO) is the main virulence protein of LM. LLO helps LM escape from the lysosome. However, the pronounced pathogenicity of LM limits its practical application as a live bacterial vector. Listeria ivanovii (LI) also displays intracellular parasitic abilities, cell to cell transfer, and other LM properties, with an elevated biosafety relative to LM. We have confirmed that LI can be used as a viable bacterial vaccine vector. However, we have also observed in vivo that LI vector vaccine candidates survive in the immune organ (spleen) for a shorter time compared with the survival time of LM and elicit weaker immune responses compared with LM. Studies have confirmed that hemolysin correlates with some important biological properties of Listeria, including cell invasion, intracellular proliferation, and the ability to induce immune responses. We speculated that the weaker immunogenicity of LI compared to LM may be related to the function of ivanolysin O (ILO). Here, we established a hemolysin gene deletion strain, LIΔilo, and a modified strain, LIΔilo:hly, whose ilo was replaced by hly. The hemolysin-modified strain was attenuated; however, it led to significantly improved invasive and proliferative activities of antigen-presenting cells, including those of RAW 264.7 macrophages, compared with the effects of LI. Mice immunized twice with LIΔilo:hly showed higher cytokine levels and better challenge protection rates than LI-immunized mice. This is the first description in Listeria carrier vaccine research of the modification of LI hemolysin to obtain a better vaccine carrier than LI. The recombinant strain LIΔilo:hly showed good biosafety and immunogenicity, and thus appears to be a good vector strain for vaccine development.

Systemic immune effects of anesthetics and their intracellular targets in tumors.

According to the result released by the World Health Organization (WHO), non-communicable diseases have occupied four of the top 10 current causes for death in the world. Cancer is one of the significant factors that trigger complications and deaths; more than 80% cancer patients require surgical or palliative treatment. In this case, anesthetic treatment is indispensable. Since cancer is a heterogeneous disease, various types of interventions can activate oncogenes or mutate tumor suppressor genes. More and more researchers believe that anesthetics have a certain effect on the long-term recurrence and metastasis of tumors, but it is still controversial whether they promote or inhibit the progression of cancer. On this basis, a series of retrospective or prospective randomized clinical trials have been conducted, but it seems to be difficult to reach a conclusion within 5 years or longer. This article focuses on the effects of anesthetic drugs on immune function and cancer and reviews their latest targets on the tumor cells, in order to provide a theoretical basis for optimizing the selection of anesthetic drugs, exploring therapeutic targets, and improving the prognosis of cancer patients.

The Probiotic Strain Bifidobacterium animalis ssp. lactis HY8002 Potentially Improves the Mucosal Integrity of an Altered Intestinal Microbial Environment.

Intestinal microbiota mediate the development and regulation of the intestinal immune system either directly or indirectly. Particularly, Bifidobacterium spp. play an important role in regulating the intestinal immunity and intestinal barrier. We demonstrated that Bifidobacterium animalis ssp. lactis HY8002, selected from eight Bifidobacterium strains by in vitro experimentation, had exceptional resistance to digestive tract conditions and high adhesion to intestinal epithelial cells and a positive effect on immunoglobulin A (IgA) secretion by Peyer's patch cells. Moreover, HY8002 restored the expression of tight junction-related genes, initially reduced by lipopolysaccharide treatment, to normal levels in human intestinal epithelial cells. Notably, HY8002 restored kanamycin-induced reduction in Peyer's patch cell numbers, serum and fecal IgA levels, and zonula occludens 1 and Toll-like receptor 2 levels in the mouse small intestine. In addition, HY8002 restores microbiome composition disturbed by kanamycin, and these microbiome changes have been found to correlate with TLR2 levels in the small intestine. Moreover, the ability of HY8002 to enhance IgA in Peyer's patch cells and ZO-1 levels in intestinal epithelial cells was significantly inhibited by a TLR2 blocking antibody, which suggests that the HY8002 improve intestinal barrier function via TLR2. Finally, whole-genome sequencing of HY8002 revealed that it did not possess any known virulence factors. Therefore, HY8002 is a promising, functional probiotic supplement to improve intestinal barrier function by improving intestinal immunity and microbiota balance.

Two-year immune effect differences between the 0-1-2-month and 0-1-6-month HBV vaccination schedule in adults.

BACKGROUND: The short-term 0-1-2-month hepatitis B virus (HBV) vaccination schedule was previously implemented in the adult population; however, its long-term immune effect remains unclear. The present study aimed to investigate (1) the 2-month and 2-year immune effects of HBV vaccination and (2) the compliance rate between the 0-1-2-month and 0-1-6-month vaccination schedules in adults. METHOD: A total of 1281 subjects tested for hepatitis B surface antigen HBsAg(-) and hepatitis B surface antibody (anti-HBs)(-) were recruited. Participants from two distant counties were inoculated with the hepatitis B yeast vaccine at 10 µg per dose, with vaccination schedules of 0, 1, and 2 months (n = 606) and 0, 1, and 6 months (n = 675); sequential follow-up was performed at 2 months and 2 years after the 3rd injection. RESULTS: There were no significant differences in the anti-HBs seroconversion rates between the those in the 0-1-2-month and 0-1-6-month vaccination schedule groups at 2 months (91.96% vs. 89.42%, p = 0.229) and 2 years (81.06% vs. 77.14%, p = 0.217). The quantitative anti-HBs level in those in the 0-1-2-month vaccination schedule group was not different from that in those in the 0-1-6-month vaccination schedule group at 2 months (anti-HBs1) (342.12 ± 378.42 mIU/ml vs. 392.38 ± 391.96 mIU/ml, p = 0.062), but it was higher at 2 years (anti-HBs2) (198.37 ± 286.44 mIU/ml vs. 155.65 ± 271.73 mIU/ml, p = 0.048). According to the subgroup analysis, the 0-1-2-month vaccination schedule induced better maintenance (p = 0.041) and longer reinforcement (p = 0.019) than the 0-1-6 vaccination schedule. The 0-1-2-month vaccination schedule group also had a higher 3rd injection completion rate (89.49% vs. 84.49%, p = 0.010). CONCLUSION: The 0-1-2-month vaccination schedule was associated with a similar short-term immune effect and might induce better long-term immune memory and a higher completion rate in the adult population. Trial registration None.

Analysis of the positive results and influencing factors of hepatitis B antibody in hospitalized neonates with AgHBs positive mothers.

Purpose: To investigate the results of positive antibody to hepatitis surface antigen(anti-HBs)in hospitalized neonates whose mothers were hepatitis B surface antigen (AgHBs) positive and to explore the influencing factors. Method: The study subjects were hospitalized neonates whose mothers were positive for AgHBs. According to the serological test results of five immune markers of hepatitis B virus (HBV), they were divided into positive for anti-HBs and negative for anti-HBs. Retrospective analysis of relevant factors affecting results of anti-HBs. Result: 269 cases (80.78%) were positive for anti-HBs and 64 cases (19.22%) were negative for anti-HBs. Univariate analysis results: the number of hepatitis B immunoglobulin (HBIG) injections after birth, whether HBIG was injected within 6 h, whether Hepatitis B vaccine (Hep B) was injected within 6 h, whether combined immunization within 12 h, whether Hep B was vaccinated on time after discharge, whether preterm birth, and whether low birth weight infants were statistically significant (P < 0.05). The results of binary logistic regression analysis: HBIG injection time ≤6 h (OR = 0.213), combined immunization time ≤12 h (OR = 0.024) were protective factors; premature infants (OR = 7.175), ALB/GLO (OR = 9.792) and failure to complete three vaccinations on time (OR = 12.659) were risk factors (P < 0.05). Conclusion: Although China has implemented a national immunization program, vaccination of hospitalized neonates whose mothers are positive for AgHBs has not been effective. Therefore, it is recommended to strengthen training for medical staff and families to ensure that neonates can complete the three doses of vaccination on time after discharge from the hospital and to strengthen follow-up for premature infants.

Immune effects of Clostridium difficile toxoid B vaccine formulated with different mucosal adjuvants through microneedle immunization / 中华微生物学和免疫学杂志

Objective:To investigate the immune effects of Clostridium difficile toxoid B (CdtB) vaccine formulated with different mucosal adjuvants through microneedle immunization, and to provide ideas for the prevention and treatment of Clostridium difficile infection. Methods:CdtB vaccine was prepared with purified Clostridium difficile toxin B(TcdB) after formaldehyde detoxification. Female BALB/c mice were immunized with different doses of vaccine alone or in combination with mucosal adjuvants. The titers of specific serum IgG and fecal IgA were detected at 0 d, 7 d, 14 d, 28 d and 42 d after immunization. The protective effects of CdtB vaccine were evaluated by cell neutralization assay and Clostridium difficile challenge infection. Results:(1) With the increase of immune dose, the mice immunized with CdtB vaccine alone by microneedle not only produced better serum specific IgG, but also had higher level of IgA in feces. (2) When the mice were immunized with CdtB vaccine containing LT or CTB adjuvant by microneedle, the trend of serum specific IgG titer in each group increased with the increase of immune dose, especially in the group containing LT adjuvant. There were significant differences in the trend of specific IgA titer in feces between the adjuvant groups and the group without adjuvant, but the adjuvant effect was not obvious. (3) No significant difference in serum IgG titer was observed between the mice immunized with 10 μg CdtB by microneedle or intraperitoneal injection, but microneedle immunization significantly increased fecal IgA level. (4) The neutralization titers of specific antibodies in mouse serum after immunization and the test results of challenge protection in mice confirmed that the use of CdtB vaccine had certain protective effects.Conclusions:CdtB vaccine had better immune effects in mice through microneedle immunization, but the adjuvant effects of LT and CTB were not significant.