With the rapid development of antibody genetic engineering, bispecific antibody technology has been advanced. They are capable of binding two or more different epitopes simultaneously, thus offering specific advantages over natural monoclonal antibodies in immunotherapy. Bispecific antibodies have been successfully used in cancer therapy (e.g. melanoma, Hodgkin's lymphoma, liver cancer, and stomach cancer) and inflammation therapy (e.g. rheumatoid arthritis, psoriasis and Crohn's disease), but are still in their early stage for viral immunotherapy. In this study, we reviewed the research progress of bispecific antibodies for immunotherapy of virus infections, especially those with good effects in vivo and in vitro, to provide references for the research and development of bispecific antibodies for antivirus treatment.
Antibodies, Bispecific ; therapeutic use ; Antibodies, Monoclonal ; Epitopes ; Humans ; Immunotherapy ; Virus Diseases

The drugs of programmed cell death 1 and its ligand 1 immune checkpoint inhibitors have ushered in a new era of anti-tumor immunotherapy, which has shown outstanding efficacy in some tumors, such as Hodgkin lymphoma, but there is still low response rate in some kinds of tumors. In recent years, bispecific antibodies prepared by cell fusion, recombinant DNA, protein engineering and other technologies can specifically bind two antigens or epitopes at the same time or successively, play a synergistic role in tumor treatment, can effectively inhibit tumor immune escape, and improve the effect of anti-tumor treatment has become a hot spot in tumor research. This paper will summarize the clinical research and development of bispecific antibodies, to provide reference for the industry.
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Antibodies, Bispecific/therapeutic use* ; Antineoplastic Agents ; DNA, Recombinant ; Epitopes ; Humans ; Immune Checkpoint Inhibitors ; Immunotherapy ; Ligands ; Lung Neoplasms/drug therapy* ; Neoplasms ; Research

Epidermal growth factor receptor (EGFR) is an attractive target for tumor therapy because it is overexpressed in the majority of solid tumors and the increase in receptor expression levels has been linked with a poor clinical prognosis. Also it is well established that blocking the interaction of EGFR and the growth factors could lead to the arrest of tumor growth and possibly result in tumor cell death. A13 is a murine monoclonal antibody (mAb) that specifically binds to various sets of EGFR-expressing tumor cells and inhibits EGF-induced EGFR phosphorylation. We isolated human immunoglobulin genes by guided selection based on the mAb A13. Four different human single chain Fvs (scFvs) were isolated from from hybrid scFv libraries containing a human VH repertoire with the VL of mAb A13 and a human VL repertoire with the VH of mAb A13. All the 4 scFvs bound to EGFR-expressing A431 cells. One scFv (SC414) with the highest affinity was converted to IgG1 (ER414). The ER414 exhibited ~17 fold lower affinity compared to the A13 mAb. In addition the ER414 inhibited an EGF-induced tyrosine phosphorylation of EGFR with much lower efficacy compared to the A13 mAb and Cetuximab (Merck KgaA, Germany). We identified that the epitope of A13 mAb is retained in ER414. This approach will provide an efficient way of converting a murine mAb to a human mAb.
Animals ; Antibodies, Monoclonal, Humanized/*genetics/immunology/therapeutic use ; Antibody Affinity ; Cell Line, Tumor ; Directed Molecular Evolution/*methods ; Epitope Mapping ; Epitopes/genetics/immunology/therapeutic use ; Humans ; *Immunotherapy ; Mice ; Neoplasms/*therapy ; Phosphorylation/drug effects ; Protein Binding ; Receptor, Epidermal Growth Factor/*antagonists & inhibitors/immunology ; Selection, Genetic ; Single-Chain Antibodies/*genetics/immunology/therapeutic use

PURPOSE: To identify new immunogenic HLA-A*33;03-restricted epitopes from the human papillomavirus (HPV) 16 E7 protein for immunotherapy against cervical cancer. MATERIALS AND METHODS: We synthesized fourteen overlapping 15-amino acid peptides and measured intracellular interferon-γ (IFN-γ) production in PBMC and CD8+ cytotoxic T lymphocytes (CTLs) after sensitization with these peptides using flow cytometry and ELISpot assay. The immunogenicity of epitopes was verified using a ⁵¹Cr release assay with SNU1299 cells. RESULTS: Among the fourteen 15-amino acid peptides, E7₄₉₋₆₃ (RAHYNIVTFCCKCDS) demonstrated the highest IFN-γ production from peripheral blood mononuclear cells (PBMCs), and CD8+ CTLs sensitized with E7₄₉₋₆₃ showed higher cytotoxic effect against SNU1299 cells than did CD8+ CTLs sensitized with other peptides or a negative control group. Thirteen 9- or 10-amino acid overlapping peptides spanning E7₄₉₋₆₃, E7₅₀₋₅₉ (AHYNIVTFCC), and E7₅₂₋₆₁ (YNIVTFCCKC) induced significantly higher IFN-γ production and cytotoxic effects against SNU1299 cells than the other peptides and negative controls, and the cytotoxicity of E7₅₀₋₅₉- and E7₅₂₋₆₁-sensitized PBMCs was induced via the cytolytic effect of CD8+ CTLs. CONCLUSION: We identified E7₅₀₋₅₉ and E7₅₂₋₆₁ as novel HPV 16 E7 epitopes for HLA-A*33;03. CD8+ CTL sensitized with these peptides result in an antitumor effect against cervical cancer cells. These epitopes could be useful for immune monitoring and immunotherapy for cervical cancer and HPV 16-related diseases including anal cancer and oropharyngeal cancer.
Amino Acid Sequence ; CD8-Positive T-Lymphocytes/immunology/metabolism ; Epitopes/*immunology/therapeutic use ; Female ; *HLA-A Antigens ; Human papillomavirus 16/*immunology ; Humans ; *Immunotherapy ; Interferon-gamma/analysis/*biosynthesis ; Leukocytes, Mononuclear/immunology/metabolism ; T-Lymphocytes, Cytotoxic/immunology/metabolism ; Uterine Cervical Neoplasms/*therapy

Objective To investigate the preventive therapeutic effect and possible mechanism of single chain variable fragments chimeric protein (SD) of ovalbumin epitopes internalizing receptor DEC-205 antibody on food allergy in mice. Methods Mice were randomly divided to five groups (control, PBS, scFv DEC 100 μg, SD 50 μg, SD 100 μg) and treated for 24 hours before OVA administration. After challenge, the serum level of OVA-specific IgE, IgG1, IgG2a and IL-4 were detected by ELISA. Infiltration of eosinophils and mast cells in the jejunum was observed by HE staining and toluidine blue staining respectively. The bone marrow of tibia and femur was isolated and cultured to obtain immature dendritic cells(BMDCs), which were further treated with LPS (10 ng/mL), TSLP (50 ng/mL), scFv DEC protein (1000 ng/mL) and SD protein (10,100,1000)ng/mL for 24 hours, and the IL-10 level of supernatant was assayed by ELISA. Results Compared with PBS group, the number of SD-treated mice with diarrhea was markedly reduced. The difference in rectal temperature and the levels of serum OVA-specific IgE, IgG1, IgG2a and IL-4 decreased significantly after prophylactic administration of SD; The number of eosinophils and mast cells in jejunum also decreased significantly while the IL-10 level in the supernatant of BMDCs increased significantly after SD intervention. Conclusion SD mitigates experimental FA response by fosters the immune tolerance property of dendritic cells.
Mice ; Animals ; Ovalbumin ; Interleukin-10 ; Single-Chain Antibodies/genetics* ; Immunoglobulin E ; Epitopes/therapeutic use* ; Interleukin-4 ; Food Hypersensitivity/prevention & control* ; Immunoglobulin G ; Recombinant Fusion Proteins/genetics* ; Mice, Inbred BALB C ; Disease Models, Animal

OBJECTIVETo investigate the immunotherapy efficacy of both helper T lymphocytes (Th) and cytotoxic T lymphocytes (CTL) epitopes augmented dendritic cells (DCs) tumor vaccine on gastric cancer.

METHODSNaïve spleen T cells were stimulated by mixed peptides (a mixture of Th epitope MAGE-3 (22-36)) primed DCs per week in vitro. After 4 cycles of restimulation, peptide specific T cells were harvested and subgroups of which were determined with flow cytometry. Cytokines secreting profiles by CD4+ T cells and cytotoxicities of CD8+ T cells on tumor cells were assessed. The protective immunity by referred DCs tumor vaccines was also monitored.

RESULTSBoth Th and CTL epitopes primed DCs could elicit both CD4+ T cells and CD8+ T cells in vitro,of which CD4+ T cells released high amount of Th1 type cytokines (IFN-gamma, IL-2) on recognizing specific antigen, as well as CD8+ T cells exhibited efficient tumor-killing capacity. The effects induced by DCs pulsed with single epitope (Th or CTL epitope) in vivo were less effective than those induced by DCs pulsed with mixture epitopes.

CONCLUSIONSBoth Th and CTL epitopes augmented DCs tumor vaccine can induce CD4+ Th1 and CD8+ CTL mediated immune responses to eradicate gastric cancer cells.

Animals ; Cancer Vaccines ; immunology ; therapeutic use ; Cell Line ; Cell Line, Tumor ; Dendritic Cells ; immunology ; Epitopes, T-Lymphocyte ; immunology ; Immunotherapy ; Melanoma, Experimental ; Mice ; Peptides ; immunology ; Stomach Neoplasms ; therapy ; T-Lymphocytes, Cytotoxic ; immunology ; T-Lymphocytes, Helper-Inducer ; immunology

The abnormal glycans expressing on the surface of tumor cells are good targets to develop carbohydrate-based anti-cancer vaccines. However, one of the major problems is that carbohydrate antigens possess weak immunogenicity. This review summarizes the recent efforts to overcome this problem: glycoconjugates produced by coupling the carbohydrate antigens and proper carrier proteins improve their immunogenicity, many glycoconjugates have entered clinical trials; the vaccines become chemically well-defined when coupling the carbohydrate antigens with a T-cell peptide epitope and an immunostimulant to form fully synthetic multi-component glycoconjugate vaccines; the modification of carbohydrate antigens in combination with the technology of metabolic oligosaccharide engineering of tumor cells induces a strong immune response; and the fact that the antibodies elicited against the unnatural carbohydrate antigens can recognize the native carbohydrate antigens on tumor cells provides a new promising strategy for the development of anti-cancer vaccines.
Animals ; Antigens, Tumor-Associated, Carbohydrate ; chemistry ; immunology ; Cancer Vaccines ; chemical synthesis ; chemistry ; immunology ; therapeutic use ; Carbohydrates ; chemistry ; immunology ; Epitopes, T-Lymphocyte ; chemistry ; immunology ; Glycoconjugates ; chemistry ; immunology ; Humans ; Immune Tolerance ; Metabolic Engineering ; methods ; Neoplasms ; prevention & control ; therapy ; Oligosaccharides ; chemistry

OBJECTIVETo develop an oral DNA vaccine based on MG(7)-Ag mimotope of gastric cancer using attenuated Salmonella typhimurium and evaluate its efficacy and protective effect.

METHODSThe eukaryotic expression vector including the MG(7)-Ag mimotope and a Th epitope was constructed, and then transduced into an attenuated Salmonella typhimurium to get the oral DNA vaccine. C57BL/6 J mice were orally immunized with 1 x 10(8) cfu Salmonella transfectants, with Salmonella harboring empty plasmid, with phophate buffered saline (PBS) as control. At the 6th week, serum titer of MG(7) antibody was detected by ELISA. In the 8th week, a [(3)H]-thymidine incorporation assay was performed to test the proliferation of murine spleen cells to the stimulant of MG(7)-Ag mimicry peptide. At the same time, Ehrlich ascites carcinoma cells expressing MG(7)-Ag were used in tumor challenge assay to evaluate the protective effect of the immunization.

RESULTSThe oral DNA vaccine induced MG(7) antibody in mice, while in vivo unprimed proliferation assay of the spleenocytes showed no difference among the three groups. Two weeks after tumor challenge, 2 in 7 immunized mice were tumor free, while none in the control group was protected.

CONCLUSIONOral DNA vaccine based on the MG(7)-Ag momitope is immunogenic. It is able to induce specific immunity response against tumor in mice, and the vaccine is partially protective.

Administration, Oral ; Amino Acid Sequence ; Animals ; Antigens, Neoplasm ; blood ; genetics ; immunology ; Base Sequence ; Cancer Vaccines ; genetics ; immunology ; therapeutic use ; Epitopes ; genetics ; immunology ; Female ; Mice ; Mice, Inbred C57BL ; Molecular Mimicry ; genetics ; immunology ; Molecular Sequence Data ; Plasmids ; genetics ; Polymerase Chain Reaction ; Stomach Neoplasms ; drug therapy ; immunology ; Treatment Outcome ; Vaccines, DNA ; genetics ; immunology ; therapeutic use

AIMTo investigate the antitumor immunity by a dendritic cell (DC) vaccine encoding secondary lymphoid chemokine gene and tumor lysate on murine prostate cancer.

METHODSDC from bone marrow of C57BL/6 were transfected with a plasmid vector expressing secondary lymphoid chemokine (SLC) cDNA by Lipofectamine 2,000 liposome and tumor lysate. Total RNA extracted from SLC+lysate-DC was used to verify the expression of SLC by reverse transcriptase-polymerase chain reaction (RT-PCR). The immunotherapeutic effect of DC vaccine on murine prostate cancer was assessed.

RESULTSWe found that in the prostate tumor model of C57BL/6 mice, the administration of SLC+lysate-DC inhibited tumor growth most significantly when compared with SLC-DC, lysate-DC, DC or phosphate buffer solution (PBS) counterparts (P < 0.01). Immunohistochemical fluorescent staining analysis showed the infiltration of more CD4(+), CD8(+) T cell and CD11c(+) DC within established tumor treated by SLC+lysate-DC vaccine than other DC vaccines (P < 0.01).

CONCLUSIONDC vaccine encoding secondary lymphoid chemokine and tumor lysate can elicit significant antitumor immunity by infiltration of CD4(+), CD8(+) T cell and DC, which might provide a potential immunotherapy method for prostate cancer.

Animals ; Antibodies, Neoplasm ; biosynthesis ; Antigens, Neoplasm ; immunology ; CD11 Antigens ; immunology ; Cancer Vaccines ; immunology ; therapeutic use ; Cell Line ; Chemokines ; biosynthesis ; Dendritic Cells ; immunology ; metabolism ; Epitopes ; immunology ; Fluorescent Antibody Technique ; Killer Cells, Natural ; immunology ; Lymphocytes ; metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Neoplasm Transplantation ; Plasmids ; genetics ; Prostatic Neoplasms ; immunology ; pathology ; prevention & control ; Reverse Transcriptase Polymerase Chain Reaction ; T-Lymphocytes ; immunology