Effects of dietary supplementation with Clostridium butyricum on the growth performance and humoral immune response in Miichthys miiuy

The effects of dietary supplementation with Clostridium butyricum on growth performance and humoral immune response in Miichthys miiuy were evaluated. One hundred and fifty Miichthys miiuy weighing approximately 200-260 g were divided into five groups and reared in 15 tanks with closed circuiting culture system. The animals were fed 5 diets： basal diet only （control） or supplemented of the basal diet with C. butyricum at doses of 10^3 （CB1）, 10^5 （CB2）, 10^7 （CB3） or 10^9 （CB4） CFU/g. Compared with the control, the serum phenoloxidase activity was significantly increased by the supplementation （P〈0.05）, acid phosphatases activity was increased significantly （P〈0.05） at the doses of 10^9 CFU/g. Serum lysozyme activity peaked at dose of 10^7 CFU/g and in the skin mucus at dose of 10^9 CFU/g. Immunoglobulin M level in the serum and skin mucus was increased except at dose of 10^3 CFU/g （P〈0.05）. The growth at the dose of 10^9 CFU/g was higher than that of the control （P〈0.05）. It is concluded that supplementation of C. butyricum can mediate the humoral immune responses and improve the growth performance in Miichthys miiuy.

Pre-evaluation of humoral immune response of Bactrian camels by the quantification of Th2 cytokines using real-time PCR

With the increasing immunological studies on camels due to the advantage of their single-chain antibodies for humanizations,it is demanding to develop an easy-to-handle evaluation method of their humoral immune response before proceeding with immunization of foreign antigens that may be toxic to camels.In this study,we quantitatively determined the expression levels of T-helper 2(Th2) cytokines in peripheral blood lymphocytes obtained from Bactrian camels by real-time PCR.The recorded kinetic profiles resulting from the immunization of ovalbumin(OVA) indicated that after immunization,Th2 cytokines including interleukin(IL) families such as IL-4,IL-10,and IL-13 in the camels were up-regulated by a factor of 1.78,3.15,and 1.22,respectively,which was validated by traditional enzyme-linked immunosorbent assay(ELISA) methods.Unlike ELISA which requires specific enzyme-labeled antibodies,this established method based on the minimal amount of blood samples holds an advantage in the preliminary evaluation of camel humoral immune response with desirable precision,which is meaningful for biomedical explorations of camel-derived antibodies.

Characterization of humoral immune responses against SARS-CoV-2 accessory proteins in infected patients and mouse model

Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the causative agent of COVID-19,encodes several accessory proteins that have been shown to play crucial roles in regulating the innate immune response.However,their expressions in infected cells and immunogenicity in infected humans and mice are still not fully understood.This study utilized various techniques such as luciferase immunoprecipitation system(LIPS),immunofluorescence assay(IFA),and western blot(WB)to detect accessory protein-specific antibodies in sera of COVID-19 patients.Specific antibodies to proteins 3a,3b,7b,8 and 9c can be detected by LIPS,but only protein 3a antibody was detected by IFA or WB.Antibodies against proteins 3a and 7b were only detected in ICU patients,which may serve as a marker for predicting disease progression.Further,we investigated the expression of accessory proteins in SARS-CoV-2-infected cells and identified the expressions of proteins 3a,6,7a,8,and 9b.We also analyzed their ability to induce antibodies in immunized mice and found that only proteins 3a,6,7a,8,9b and 9c were able to induce measurable antibody productions,but these antibodies lacked neutralizing activities and did not protect mice from SARS-CoV-2 infection.Our findings validate the expression of SARS-CoV-2 accessory proteins and elucidate their humoral immune response,providing a basis for protein detection assays and their role in pathogenesis.

Humoral immune responses induced by anti-idiotypic antibody fusion protein of 6B11scFv/hGM-CSF in BALB/c mice

Background We have previously developed and characterized a monoclonal anti-idiotype antibody, designated 6B 11, which mimics an ovarian carcinoma associated antigen OC166-9 and whose corresponding monoclonal antibody is COC166-9 （Abl）. In this study, we evaluate the humoral immune responses induced by the fusion protein 6B11 single-chain variable fragment （scFv）/human granulocyte macrophage colony-stimulating factor （hGM-CSF） and 6B 1 lscFv in BALB/c mice. Methods The fusion protein 6B 11 scFv/hGM-CSF was constructed by fusing a recombinant single-chain variable fragment of 6B11scFv to GM-CSE BALB/c mice were administrated by 6B11scFv/hGM-CSF and 6B11scFv, respectively. Results The fusion protein 6B11scFv/hGM-CSF retained binding to the anti-mouse F（ab）2＇ and was also biologically active as measured by proliferation of human GM-CSF dependent cell TF1 in vitro. After immunization with the 6B11scFv/hGM-CSF and 6BllScFv, BALB/c mice showed significantly enhanced Ab3 antibody responses to 6B11 scFv/hGM-CSF compared with the 6B11 scFv alone. The level of Ab3 was the highest after the first week and maintained for five weeks after the last immunization. Another booster was given when the Ab3 titer descended, and it would reach to the high level in a week. Conclusion The fusion protein 6B11scFv/hGM-CSF can induce humoral immunity against ovarian carcinoma in vivo. We also provide the theoretical foundation for the application of the fusion protein 6B11 scFv/hGM-CSF for active immunotherapy of ovarian cancer.

DNA vaccine prime and replicating vaccinia vaccine boost induce robust humoral and cellular immune responses against MERS-CoV in mice

As of December 2022,2603 laboratory-identified Middle East respiratory syndrome coronavirus(MERS-CoV)infections and 935 associated deaths,with a mortality rate of 36%,had been reported to the World Health Organization(WHO).However,there are still no vaccines for MERS-CoV,which makes the prevention and control of MERS-CoV difficult.In this study,we generated two DNA vaccine candidates by integrating MERS-CoV Spike(S)gene into a replicating Vaccinia Tian Tan(VTT)vector.Compared to homologous immunization with either vaccine,mice immunized with DNA vaccine prime and VTT vaccine boost exhibited much stronger and durable humoral and cellular immune responses.The immunized mice produced robust binding antibodies and broad neutralizing antibodies against the EMC2012,England1 and KNIH strains of MERS-CoV.Prime-Boost immunization also induced strong MERS-S specific T cells responses,with high memory and poly-functional(CD107a-IFN-γ-TNF-α)effector CD8t T cells.In conclusion,the research demonstrated that DNA-Prime/VTT-Boost strategy could elicit robust and balanced humoral and cellular immune responses against MERS-CoV-S.This study not only provides a promising set of MERS-CoV vaccine candidates,but also proposes a heterologous sequential immunization strategy worthy of further development.

Maternal-derived antibodies hinder the antibody response to H9N2 AIV inactivated vaccine in the field

The H9N2 subtype avian influenza virus(AIV)inactivated vaccine has been used extensively in poultry farms,but it often fails to stimulate a sufficiently high immune response in poultry in the field,although it works well in laboratory experiments;hence,the virus still causes economic damage every year and poses a potential threat to public health.Based on surveillance data collected in the field,we found that broilers with high levels of maternal-derived antibodies(MDAs)against H9N2 virus did not produce high levels of antibodies after vaccination with a commercial H9N2 inactivated vaccine.In contrast,specific pathogen-free(SPF)chickens without MDAs responded efficiently to that vaccination.When MDAs were mimicked by administering passively transferred antibodies(PTAs)into SPF chickens in the laboratory,similar results were observed:H9N2-specific PTAs inhibited humoral immunity against the H9N2 inactivated vaccine,suggesting that H9N2-specific MDAs might hinder the generation of antibodies when H9N2 inactivated vaccine was used.After challenge with homologous H9N2 virus,the virus was detected in oropharyngeal swabs of the vaccinated and unvaccinated chickens with PTAs but not in the vaccinated chickens without PTAs,indicating that H9N2-specific MDAs were indeed one of the reasons for H9N2 inactivated vaccine failure in the field.When different titers of PTAs were used to mimic MDAs in SPF chickens,high(HI=12 log2)and medium(HI=log 9 log2)titers of PTAs reduced the generation of H9N2-specific antibodies after the first vaccination,but a booster dose would induce a high and faster humoral immune response even of PTA interference.This study strongly suggested that high or medium titers of MDAs might explain H9N2 inactivated vaccine failure in the field.

The woodchuck as an animal model for pathogenesis and therapy of chronic hepatitis B virus infection

This review describes the woodchuck and the woodchuck hepatitis virus (WHV) as an animal model for pathogenesis and therapy of chronic hepatitis B virus (HBV) infection and disease in humans. The establishment of woodchuck breeding colonies, and use of laboratory-reared woodchucks infected with defined WHV inocula, have enhanced our understanding of the virology and immunology of HBV infection and disease pathogenesis, including major sequelae like chronic hepatitis and hepatocellular carcinoma. The role of persistent WHV infection and of viral load on the natural history of infection and disease progression has been firmly established along the way. More recently, the model has shed new light on the role of host immune responses in these natural processes, and on how the immune system of the chronic carrier can be manipulated therapeutically to reduce or delay serious disease sequelae through induction of the recovery phenotype. The woodchuck is an outbred species and is not well defined immunologically due to a limitation of available host markers. However, the recent development of several key host response assays for woodchucks provides experimental opportunities for further mechanistic studies of outcome predictors in neonatal- and adult-acquired infections. Understanding the virological and immunological mechanisms responsible for resolution of self-limited infection, andfor the onset and maintenance of chronic infection, will greatly facilitate the development of successful strategies for the therapeutic eradication of established chronic HBV infection. Likewise, the results of drug efficacy and toxicity studies in the chronic carrier woodchucks are predictive for responses of patients chronically infected with HBV. Therefore, chronic WHV carrier woodchucks provide a well-characterized mammalian model for preclinical evaluation of the safety and efficacy of drug candidates, experimental therapeutic vaccines, and immunomodulators for the treatment and prevention of HBV disease sequelae.

Multiplexed Biosensing Diagnostic Platforms Detecting Autoantibodies to Tumor-Associated Antigens from Exosomes Released by CRC Cells and Tissue Samples Showed High Diagnostic Ability for Colorectal Cancer

Colorectal cancer(CRC)is the second leading cause of cancer-related death worldwide.The five-year survival rate of CRC patients depends on the stage at diagnosis,being higher than 80%when CRC is diagnosed in the early stages but lower than 10%when CRC is diagnosed in advanced stages.Autoantibodies against specific CRC autoantigens(tumor-associated antigens(TAAs))in the sera of patients have been widely demonstrated to aid in early diagnosis.Thus,we herein aim to identify autoantigens target of autoantibodies specific to CRC that possess a significant ability to discriminate between CRC patients and healthy individuals by means of liquid biopsy.To that end,we examined the protein content of the exosomes released by five CRC cell lines and tissue samples from CRC patients by means of immunoprecipitation coupled with mass spectrometry analysis.A total of 103 proteins were identified as potential autoantigens specific to CRC.After bioinformatics and meta-analysis,we selected 15 proteins that are more likely to be actual CRC autoantigens in order to evaluate their role in CRC prognosis by Western blot(WB)and immunohistochemistry(IHC).We found dysregulation at the protein level for 11 of these proteins in both tissue and plasma exosome samples from patients,along with an association of nine of these proteins with CRC prognosis.After validation,all but one showed a statistically significant high diagnostic ability to distinguish CRC patients and individuals with premalignant lesions from healthy individuals,either by luminescence Halotag-based beads,or by a multiplexed biosensing platform involving the use of magnetic microcarriers as solid support modified with covalently immobilized Halotag fusion proteins constructed for CRC detection.Taken together,our results highlight the usefulness of the approach defined here to identify the TAAs specific to chronic diseases;they also demonstrate that the measurement of autoantibody levels in plasma against the TAAs identified here could be integrated into a point-of-care(POC)device for CRC detection with high diagnostic ability.

Immunogenicity of the Spike Glycoprotein of Bat SARS-like Coronavirus

A group of SARS-like coronaviruses(SL-CoV)have been identified in horseshoe bats.Despite SL-CoVs and SARS-CoV share identical genome structure and high-level sequence similarity,SL-CoV does not bind to the same cellular receptor as for SARS-CoV and the N-terminus of the S proteins only share 64%amino acid identity,suggesting there are fundamental differences between these two groups of coronaviruses.To gain insight into the basis of this difference,we established a recombinant adenovirus system expressing the S protein from SL-CoV(rAd-Rp3-S)to investigate its immune characterization.Our results showed that immunized mice generated strong humoral immune responses against the SL-CoV S protein.Moreover,a strong cellular immune response demonstrated by elevated IFN-γand IL-6 levels was also observed in these mice.However,the induced antibody from these mice had weaker cross-reaction with the SARS-CoV S protein,and did not neutralize HIV pseudotyped with SARS-CoV S protein.These results demonstrated that the immunogenicity of the SL-CoV S protein is distinct from that of SARS-CoV,which may cause the immunological differences between human SARS-CoV and bat SL-CoV.Furthermore,the recombinant virus could serve as a potential vaccine candidate against bat SL-CoV infection.

Immune responses to SARS-CoV-2 infection in Humans and ACE2 humanized mice

The coronavirus disease 2019(COVID-19)pandemic caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)represents a major public health threat worldwide.Insight into protective and pathogenic aspects of SARS-CoV-2 immune responses is critical to work out effective therapeutics and develop vaccines for controlling the disease.Here,we review the present literature describing the innate and adaptive immune responses including innate immune cells,cytokine responses,antibody responses and T cell responses against SARS-CoV-2 in human infection,as well as in AEC2-humanized mouse infection.We also summarize the now known and unknown about the role of the SARS-CoV-2 immune responses.By better understanding the mechanisms that drive the immune responses,we can tailor treatment strategies at specific disease stages and improve our response to this worldwide public health threat.

Global properties of nonlinear humoral immunity viral infection models

In this paper, we consider two nonlinear models for viral infection with humoraL immu- nity. The first model contains four compartments; uninfected target cells, actively infected cells, free virus particles and B cells. The second model is a modification of the first one by including the latently infected cells. The incidence rate, removal rate of infected cells, production rate of viruses and the latent-to-active conversion rate are given by more general nonlinear functions. We have established a set of conditions on these general functions and determined two threshold parameters for each model which are sufficient to determine the global dynamics of the models. The global asymptotic stability of all equilibria of the models has been proven by using Lyapunov theory and applying LaSalle＇s invariance principle. We have performed some numerical simulations for the models with specific forms of the general functions. We have shown that, the numerical results are consistent with the theoretical results.