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.

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.

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.

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.

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.