• Biomolecules & Therapeutics
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• v.13 no.2
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• pp.101-106
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• 2005

The generation of secretory IgA antibodies (Abs) for specific immune protection of mucosal surfaces depends on stimulation of the mucosal immune system, but this is not effectively achieved by parenteral or even oral administration of most soluble antigens. Thus, to produce a possible vaccine antigen against urinary tract infections, the uropathogenic E. coli (UPEC) adhesin was genetically coupled to the heat-labile Escherichia coli enterotoxin A2B (ltxa2b) gene and cloned into a pMAL-p2E expression vector. The chimeric construction of pMALfimH/ltxa2b was then transformed into E. coli K-12 TB1 and its nucleotide sequence was verified. The chimeric protein was then purified by applying the affinity chromatography. The purified chimeric protein was confirmed by SDS-PAGE and westem blotting using antibodies to the maltose binding protein (MBP) or the heat labile E. coli subunit B (LTXB), plus the N-terminal amino acid sequence was analyzedd. The orderly-assembled chimeric protein was confirmed by a modified $G_{M1}$-ganglioside ELISA using antibodies to adhesin. The results indicate that the purified chimeric protein was an Adhesin/LTXA2B protein containing UPEC adhesin and the $G_{M1}$-ganglioside binding activity of LTXB. thisstudy also demonstrate that peroral administration of this chimeric immunogen in mice elicited high level of secretory IgA (sIgA) and serum IgG Abs to the UPEC adhesin. The results suggest that the genetically linked LTXA2B acts as a useful mucosal adjuvant, and that adhesin/LTXA2A chimeric protein might be a potential antigen for oral immunization against UPEC.

• Biomolecules & Therapeutics
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• v.32 no.4
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• pp.424-431
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• 2024

Among the therapeutic strategies in cancer immunotherapy-such as immune-modulating antibodies, cancer vaccines, or adoptive T cell transfer-T cells have been an attractive target due to their cytotoxicity toward tumor cells and the tumor antigen-specific binding of their receptors. Leveraging the unique properties of T cells, chimeric antigen receptor-T cells and T cell receptor (TCR)-T cells were developed through genetic modification of their receptors, enhancing the specificity and effectiveness of T cell therapy. Adoptive cell transfer of chimeric antigen receptor-T cells has been successful for the treatment of hematological malignancies. To expand T cell therapy to solid tumors, T cells are modified to express defined TCR targeting tumor associated antigen, which is called TCR-T therapy. This review discusses anti-tumor T cell therapies, with a focus on engineered TCR-T cell therapy. We outline the characteristics of TCR-T cell therapy and its clinical application to non-hematological malignancies.

• Biomolecules & Therapeutics
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• v.11 no.3
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• pp.157-162
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• 2003

The generation of secretory IgA antibodies(Abs) for specific immune protection of mucosal surfaces depends on stimulation of the mucosal immune system, but this is not effectively achieved by parenteral or even oral administration of most soluble antigens. Thus, to produce a possible vaccine antigen against urinary tract infections, the uropathogenic E. coli (UPEC) adhesin was genetically coupled to the ctxa2b gene and cloned into a pMAL-p2E expression vector. The chimeric construction of pMALfimHIctxa2b was then transformed into E. coli K-12 TB1 and its nucleotide sequence was verified. The chimeric protein was then purified by applying the affinity chromatography. The purified chimeric protein was confirmed by SDS-PAGE and western blotting using antibodies to the maltose binding protein (MBP) or the cholera toxin subunit B (CTXB), plus the N-terminal amino acid sequence was analyzed. The orderly-assembled chimeric protein was confirmed by a modified $G_{M1}$-ganglioside ELISA using antibodies to adhesin. The results indicate that the purified chimeric protein was an Adhesin/CTXA2B protein containing UPEC adhesin and the $G_{M1}$-ganglioside binding activity of CTXB. This study also demonstrate that peroral administration of this chimeric immunogen in mice elicited high level of secretory IgA and serum IgG Abs to the UPEC adhesin. The results suggest that the genetically linked CTXA2B acts as a useful mucosal adjuvant, and that the adhesin/CTXA2B chimeric protein might be a potential antigen for oral immunization against UPEC.

• Journal of Microbiology and Biotechnology
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• v.14 no.3
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• pp.490-497
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• 2004

Although the E. coli heat-labile enterotoxin B subunit (LTB) is known to be a potent mucosal adjuvant towards co-administrated unrelated antigens and immunoregulator in T-helper 1-type-mediated autoimmune diseases, a more efficient and useful LTB is still required for prospective vaccine adjuvants. To determine whether a novel chimeric LTB subunit would produce an enhanced mucosal adjuvant activity and immune response, a number of LTB subunits were genetically fused with chimeric proteins using the epitope genes of the envelope glycoprotein E2 (gp51-54) from the classical swine fever virus (CSFV). It was found that the total serum immunoglobulin (Ig) levels of BALB/c mice orally immunized with chimeric proteins containing an N-terminal linked LTB subunit (LE1, LE2, and LE3) were higher than those of mice immunized with LTB, E2 epitope, and chimeric proteins that contained a C-terminal linked LTB subunit. In particular, immunization with LE1 markedly increased both the total serum Ig and fecal IgA level compared to immunization with LTB or the E2 epitope. Accordingly, the current results demonstrated that the LTB subunit in a chimeric protein exhibited a strong mucosal adjuvant effect as a carrier molecule, while the chimeric protein containing the LTB subunit stimulated the mucosal immune system by mediating the induction of antigen-specific serum Ig and mucosal IgA. Consequently, an LE1-mediated mucosal response may contribute to the development of effective antidiarrhea vaccine adjuvants.

• The Korean Journal of Physiology and Pharmacology
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• v.27 no.3
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• pp.241-256
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• 2023

Although chimeric antigen receptor T cell (CAR-T) is a promising immunotherapy in hematological malignancies, there remain many obstacles to CART cell therapy for solid tumors. Identifying appropriate tumor-associated antigens (TAAs) is especially critical for success. Using a bioinformatics approach, we identified common potential TAAs for CAR-T cell immunotherapy in solid tumors. We used the GEO database as a training dataset to find differentially expressed genes (DEGs) and verified candidates using the TCGA database, obtaining seven common DEGs (HM13, SDC1, MST1R, HMMR, MIF, CD24, and PDIA4). Then, we used MERAV to analyze the expression of six genes in normal tissues to determine the ideal target genes. Finally, we analyzed tumor microenvironment factors. The results of major microenvironment factor analyses showed that MDSCs, CXCL1, CXCL12, CXCL5, CCL2, CCL5, TGF- β, CTLA-4, and IFN-γ were significantly overexpressed in breast cancer. The expression of MST1R was positively correlated with TGF- β, CTLA-4, and IFN-γ. In lung adenocarcinoma, MDSCs, Tregs, CXCL12, CXCL5, CCL2, PD-L1, CTLA-4, and IFN-γ were significantly overexpressed in tumor tissues. The expression of MST1R was positively correlated with TGF- β, CTLA-4, and IFN-γ. In bladder cancer, CXCL12, CCL2, and CXCL5 were significantly overexpressed in tumor tissues. MST1R expression was positively correlated with TGF- β. Our results demonstrate that MST1R has the potential as a new target antigen for treating breast cancer, lung adenocarcinoma, and bladder cancer and may be used as a progression indicator for bladder cancer.

• Clinical and Experimental Vaccine Research
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• v.12 no.4
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• pp.304-312
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• 2023

Purpose: Due to the many problems with commercially available vaccines, the production of effective vaccines against brucellosis is a necessity. The aim of this study was to evaluate the immune responses caused by the chimeric protein consisting of trigger factor, Bp26, and Omp31 (TBO) along with aluminum hydroxide (AH/TBO) and selenium (Se/TBO) nanoparticles (NPs) as adjuvants in mouse model. Materials and Methods: Recombinant antigen expression was induced in Escherichia coli BL21 (DE3) bacteria using IPTG (isopropyl-d-1-thiogalactopyranoside). Purification and characterization of recombinant protein was conducted through NiFe₃O₄ NPs, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and Western blot. NP characteristics, including morphology and particle size, were measured in vitro. The recombinant TBO was loaded on to AH and Se NPs and were administered subcutaneously. After mice immunization, measurement of antibody titter and protection assay was performed. Results: The average sizes of AH and Se NPs were about 60 nm and 150 nm, respectively. The enzyme-linked immunosorbent assay results showed that the serum of mice immunized by subcutaneous injection with both nanovaccines produced significant immunoglobulin G (IgG) responses against the chimeric antigen. The results of TBO-specific IgG isotype (IgG2a/IgG1) analysis showed that both AH and Se NPs induced a type to T-helper immune response. In addition, the results of the challenge with the pathogenic strain of Brucella melitensis 16M showed that vaccinated mice with AH/TBO NPs indicated a higher reduction of bacterial culture than immunized mice with Se/TBO NPs and TBO alone. Conclusion: The results showed that AH NPs carrying chimeric antigen can be a promising vaccine candidate against brucellosis by producing protective immunity.

• Korean Journal of Radiology
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• v.25 no.4
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• pp.399-402
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• 2024

• Korean Journal of Microbiology
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• v.27 no.1
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• pp.16-20
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• 1989

The effect of E. coli plasmid DNA sequences contained by chimeric vectors on plasmid replication was investigated. We constructed YRp7- or 2.$\mu$m circle-based plasmids containing E. coli plasmid DNA sequences and those not containing it. By examining their maintenance in yeast, we showed that plasmid without E. coli plasmid DNA sdquences was nore stable and presented higher copy number, and espressed higher level of hepatitis B viral surface antigen as a foreign gene. This result suggested that E. coli plasmid DNA sequences within chimeric plasmid somehow inhibited plasmid replication in yeast.

• BMB Reports
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• v.57 no.8
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• pp.369-374
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• 2024

Antigen 43 (Ag43) proteins, found on the outer membrane of Escherichia coli, are β-sheets that fold into a unique cylindrical structure known as a β-barrel. There are several known structural similarities between bacterial Ag43 autotransporters and physical components; however, the factors that stabilize the barrel and the mechanism for Ag43 passenger domain-mediated translocation across the pore of the β-barrel remain unclear. In this study, we analyzed Ag43β-enhanced green fluorescent protein chimeric variants to provide new insights into the autotransporter Ag43β-barrel assembly, focusing on the impact of the α-helical linker domain. Among the chimeric variants, Ag43β700 showed the highest surface display, which was confirmed through extracellular protease digestion, flow cytometry, and an evaluation of outer membrane vesicles (OMVs). The Ag43β700 module offered reliable information on stable barrel folding and chimera expression at the exterior of the OMVs.

• BMB Reports
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• v.54 no.1
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• pp.44-58
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• 2021

Natural killer (NK) cells, key antitumor effectors of the innate immune system, are endowed with the unique ability to spontaneously eliminate cells undergoing a neoplastic transformation. Given their broad reactivity against diverse types of cancer and close association with cancer prognosis, NK cells have gained considerable attention as a promising therapeutic target for cancer immunotherapy. NK cell-based therapies have demonstrated favorable clinical efficacies in several hematological malignancies but limited success in solid tumors, thus highlighting the need to develop new therapeutic strategies to restore and optimize anti-tumor activity while preventing tumor immune escape. The current therapeutic modalities yielding encouraging results in clinical trials include the blockade of immune checkpoint receptors to overcome the immune-evasion mechanism used by tumors and the incorporation of tumor-directed chimeric antigen receptors to enhance NK cell anti-tumor specificity and activity. These observations, together with recent advances in the understanding of NK cell activation within the tumor microenvironment, will facilitate the optimal design of NK cell-based therapy against a broad range of cancers and, more desirably, refractory cancers.