• BMB Reports
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• 제53권8호
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• pp.442-447
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• 2020

The non-viral delivery of genes into macrophages, known as hard-to-transfect cells, is a challenge. In this study, the microporation of a CpG-free and small plasmid (pCGfd-GFP) showed high transfection efficiency, sustainable transgene expression, and good cell viability in the transfections of Raw 264.7 and primary bone marrow-derived macrophages. The non-viral method using the pCGfd vector encoding anti-EGFR single-chain Fv fused with Fc (scFv-Fc) generated the macrophages secreting anti-EGFR scFv-Fc. These macrophages effectively phagocytized tumor cells expressing EGFR through the antibody-dependent mechanism, as was proved by experiments using EGFR-knockout tumor cells. Finally, peri-tumoral injections of anti-EGFR scFv-Fc-secreting macrophages were shown to inhibit tumor growth in the xenograft mouse model.

• 한국어병학회지
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• 제23권1호
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• pp.9-16
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• 2010

We determined the effects of temperature shifts on the kinetics of the numbers of antibody-secreting cell (ASC) in the olive flounder Paralichthys olivaceus immunised with formalin-killed Edwardsiella tarda. When fish that were acclimated to $22^{\circ}C$ and immunised at that temperature were transferred to a lower temperature ($12^{\circ}C$) at a various times (immediately, 1, 2 or 4 weeks) after immunisation, both further differentiation of B cells and secretion of antibody from the ASC developed at $22^{\circ}C$ were suppressed at $12^{\circ}C$. However, in the converse experiment ($12^{\circ}C$ to $22^{\circ}C$), the magnitude of the humoral immune response was recovered independent of the time of the transfer after immunisation at low temperature, even though the peak levels of each transferred group did not reach the level found in $22^{\circ}C$ control group. The results were confirmed by counting the number of specific antibody secreting cells (SASC) in the spleen. This study provides the evidences of the immune reaction that the potential for antibody production in B cells of flounder, the most important species in aquatic industry of Korea, immunized at high temperature is suppressed by subsequent exposure to low temperature and that low temperature-induced humoral immuno suppression can be reversed by exposure to a higher temperature.

• 한국임상수의학회지
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• 제8권1호
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• pp.1-10
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• 1991

The B-lymphocyte differentiation from committed B-cell progenitors to antibody-secreting cells was discussed. B-cell progenitors derived from hematopoietic stem cells undergo the rearrangement of immunoglobulin(Ig) gene. The earliest cells as B-cell precursors have cytoplasmic Is(${\mu}$ chain). The entire Is molecule is expressed on the surface after synthesis of L chain. The resting B cells(Go stage) stimulated by binding antigen via Ig-receptors are activated(G$_1$ stage) and followed by proliferation(S stage), coupled with further selection(affinity maturation. class switch). The production of antibody against a particular antigen depends on the activation of B cells with surface Is capable of reacting with that antigen. This process does not occur in isolation but is controlled by helper and suppressor T cells and antigen presenting cells(APC). The mechanism of T cell-dependent B-cell response for production of antibody is largely explained by the cell to cell cooperation and soluble helper factors of T cells. 1) The antigen specific B cells and helper T cells are linked by Is-receptors, leading to the delivery of helper signals to the B cells. 2) Helper T cells recognize the processed antigen-derived peptides with the MHC class II molecules(la antigen) and is stimulated to secrete B-cell proliferation and differentiation factors which activate B cells of different antigenic specificity. The two models are shown currently 1) At low antigen concentration, only the antigen-specific B cell binds antigen and presents antigen-derived peptides with la molecules to helper T cells, which are stimulated to secrete cytokines(IL-4, IL-5, etc.) and 2) At high antigen concentration, antigen-derived peptides are presented by specific B cells, by B cells that endocytose the antigens, as well as by APC Cytokines secreted from helper T cells also lead to the activation of B cells and even bystander B cells in the on- vironmment and differentiate them into antibody-secreting plasma cells.

• 한국축산식품학회:학술대회논문집
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• 한국축산식품학회 2001년도 임시총회 및 제28차 추계학술발표회
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• pp.43-56
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• 2001

Colostrum contains various kinds of cytokines including TGF-${\beta}$ which is known to be multifunctional in immune response and act as an anti-inflammatory agent. First, we measured the amount of TGF-${\beta}$ in bovine and human colostrum. Expression pattern of TGF-${\beta}$ isotypes was dramatically different between human and bovine colostrial samples. Bovine colostrum collected on day 1 post-delivery retained $41.79{\pm}16.96ng/ml$ of TGF-${\beta}$ 1 and $108.4{\pm}78.65ng/ml$ of TGF-${\beta}$ 2 while in human, $284{\pm}124.75ng/ml$ of TGF-${\beta}$ 1 and $29.75{\pm}6.73ng/ml$ of TGF-${\beta}$ 2. Thus, TGF-${\beta}$ is the predominant TGF-${\beta}$ isotype in bovine colostrum and vice versa in human colostrum. Both TGF-${\beta}$ isotypes diminished significantly in human and bovine colostrum with time. Next, biological activity of colostrial samples was examined in vitro. Both human and bovine colostrum increased IgA synthesis by LPS-activated mouse spleen B cells, which is a typical effect of TGF-${\beta}$ on the mouse B cell differentiation. Futhermore, we found that anti-proliferative activity in MV1LU cells by colostrum samples disappeared by addition of anti-TGF-${\beta}$ 1 and anti-TGF-${\beta}$ 2 antibody. In conclusion, there are substantial amounts of biologically active TGF-${\beta}$ 1 and TGF-${\beta}$ 2 in bovine and human colostrum. The results that the colostrum can increase IgA expression has important implications since IgA is the major Ig class produced in the gastrointestinal tract. We have previously shown that the stimulatory effect of Bifidobacteria bifidum on spllen B cells was quite similar to that of LPS which is a well-known polyclonal activator for murine B cells. In the present study, we further asked whether B. bifidum regulate the synthesis of IgA by mucosal lymphoid cells present in Peyers patches (PP) and mesenteric lymph nodes (MLN). B. bifidum alone, but not C. perfringens, significantly induced overall IgA and IgM synthesis by both MLN and PP cells. This observation indicates that B. bifidum possesses a modulatory effect on the mucosal antibody production in vivo. We, therefore, investigated the mucosal antibody prodduction following peroral administration of B. bifidum to mice. Ingested B. bifidum significantly increased the numbers of Ig (IgM, IgG, and IgA) secreting cells in the culture of both MLN and spleen cells, indicating that peroally introduced B. bifidum enhances mucosal and systemic antibody response. Importantly, however, B. bifidum itself does not induce the own specific antibody responses, implying that B. bifidum do not incite any unwanted immune reaction. Subsequently, it was found that excapsulation of B. bifidum further augments the total IgA production by increasing the number of IgA-secreting cells in the culture of both MLN and spleen cells. Finally, we found that the immuno-stimulating activity of B. bifidum is due to its cell wall components but not due to any actively secreting component(s) from bacteria. Thus our data reveal that peroral administration of B. bifidum can enhance intestinal IgA production and that encapsulation of B. bifidum further reinforces the IgA production.

• 한국수산과학회지
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• 제32권4호
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• pp.420-426
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• 1999

한국 양식산업에서 중요한 어종인 넙치 (Paralichthys olivaceus) 포르말린으로 처리한 E. tarda를 항원으로 하였을 때의 면역반응 분석을 위하여 ELISPOT 기법을 적정화시킨 후 넙치의 각 장기에 있는 총 항체생성세포와 특이 항체생성세포를 계수하는데 응용하고자 하였다. 전신과 비장의 항체생성세포를 2.5시간 이상 96 well plate에 배양하면 충분히 분석이 가능하였다. 그러나 총 또는 특이 항체생성세포 분석을 위하여 과량의 토끼 항 넙치 면역글로불린 또는 E. tarda 항원을 plate에 coating하는 것은 오히려 ELISPOT법의 감도를 감소시키는 것으로 나타났다. ELISPOT법의 특이성은 단백질 합성 억제제인 cycloheximide를 처리한 임파세포에서 총 항체생성세포가 발견되지 않는 것으로서 입증할 수 있었다. 특이 항체생성세포 수의 최대치는 면역 3주째에 나타났으며 이후 계속 빠르게 감소하여 7주째는 거의 발견되지 않았다. 이러한 반응은 신장과 비장에서 유사하게 나타나 임파장기에 따른 차이점은 발견할 수 없었다. 면역 후 2주와 3주 사이에 혈청내 특이 항체량 또한 빠르게 증가하여 ELISPOT법으로 분석된 특이 항체생성세포 수의 변화와 일치함을 발견할 수 있었다. 그러나 증가된 혈청내 특이 항체량이 면역 5주부터 실험 종료 시점까지 계속 높은 수준으로 유지되고 있는 것은 급격한 감소를 보이는 특이 항체생성세포의 동력학적 변화와는 명확히 구별되는 점이었다.

• BMB Reports
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• 제32권5호
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• pp.474-479
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• 1999

Using a hybridoma technique, spleen cells of Balb/c mice immunized with human chorionic gonadotropin (hCG) were fused with NS-1 mouse myeloma cells. Two hybrid cell lines, clones KS-8 and KS-19, secreting monoclonal antibodies to hCG, were isolated. KS-8 and KS-19 belong to the immunoglobulin $G_1$ subclass. With the aid of a double-antibody radioimmunoassay, it was established that the KS-8 monoclonal antibody recognizes an immunodeterminant of the $\beta$-subunit of hCG, whereas the KS-19 monoclonal antibody recognizes an epitope present on the $\alpha$-subunit of hCG. The KS-8 monoclonal antibody specifically reacts with human chorionic gonadotropin and shows cross-reactivity of less than 0.3% to other related human glycoprotein hormones. On the other hand, using a hemagglutination test based on antibody-induced agglutination of sheep red blood cells coated with hCG, It was shown that only the KS-19 monoclonal antibody was capable of inducing a positive reaction, although both monoclonal antibodies had similar binding capacity to the coated cells. The results from the dual screening procedures demonstrate that KS-8 and KS-19 monoclonal antibodies show high sensitivity in two different assays, and are hence useful for the qualitative and quantitative determination of hCG by both radioimmunoassay and hemagglutination inhibition tests.

• 미생물학회지
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• 제23권1호
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• pp.64-68
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• 1985

페디스토마 성충의 단백질을 정제하여 이를 항원으로 면역시킨 mouse의 spleen cell과 myeloma cell을 세포융합 시킨 결과 융합율은 56% 이었고. 3차 cloning한 후의 항체생산율은 89% 이였으며, 이들 융합세포로 부터 IgM을 생산하는 hybridoma clone과 IgG을 생산하는 hybridoma clone을 얻었다. IgM을 생산하는 hybridoma clone의 supernate는 antibody titer가 희석농도 1 : 64까지 양성이었고. IgG을 생산하는 hybridoma clone의 supernate는 1 : 256까지 양성이었다.

• 약학회지
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• 제31권5호
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• pp.253-265
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• 1987

To develop hybridomas secreting monoclonal antibodies to be used as unlimited sources of reagents indispensable for the diagnosis and treatement of leukemic malignancy, a monoclonal antibody was generated to human pre-T leukemia cells (Jurkat). Hybridomas were produced against Jurkat cell line by fusing spleen cells from hyperimmunized mice with murine plasmacytoma cells (P3$\times$63Ag8. V653). One monoclonal antibody derived from this fusion, designated DMJ-2 was reactive with T-cell lines (Jurkat, Molt-4 and RPMI-8402) and normal peripheral E-rosette forming T cells, but unreactive with B-cell lines (Daudi, Nalm-6) and non-T, non-B cell line (K562). Conclusively DMJ-2 reactive with mature and immature T-lineage lymphoid cells.

• 약학회지
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• 제38권3호
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• pp.351-357
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• 1994

The levels of maternal immunity enhancing factor(MIEF), which is an immunomodulatory protein identified from bovine colostrum, were determined by indirect competitive enzyme-linked immunosorbent assay(ELISA) for the colostrum and normal milk collected during the first two weeks of lactation. The mean concentration of MIEF in the colostrum of the first day of lactation was $109\;{\mu}g/ml$, and fell from the third day of lactation to $3{\sim}4\;{\mu}g/ml$. The molecular weight of the purified MIEF determined by reducing SDS-PAGE and TSK G2000SW column chromatography was 22,000 and 24,000 daltons, respectively, showing that MIEF is a monomeric peptide in its native form. To examine the capacity of MIEF to induce differentiation of B Lymphocytes, human tonsillar Iymphocytes were cultured in the presence of different concentrations of MIEF, and then antibody secreting cells were enumerated by enzyme-linked immunospot(ELISPOT) assay. When added to cultures of human tonsillar Lymphocytes, MIEF induced differentiation of resting B Iymphocyte to antibody secreting plasma cells as efficiently as LPS.

• 대한바이러스학회지
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• 제27권1호
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• pp.9-17
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• 1997

Hepatitis C virus (HCV) E2 protein is known to be one of putative envelope proteins. To develop a sensitive detection method for HCV infected tissues and cells, monoclonal antibodys (MAbs) to the E2 protein of HCV were prepared from mice immunized with recombinant baculovirus-expressing E2 protein (Bac-E2). Several hybridoma clones secreting various levels of MAb were isolated and isotypes of these MAb were determined. One clone (L.2.3.3) was used for ascites production and the E2-MAb was purified and characterized. The L.2.3.3 reacted well with both Bac-E2 and E. coli expressed glutathione-S-transferase-E2 (GST-E2) fusion proteins. Using HCV patient sera, E2 envelope protein was found to be localized in the cell membrane boundary both in CHO cells and insect cells which express HCV E2 protein. Similar result was obtained when same cells were treated with the MAb L.2.3.3. These results demonstrated that Bac-E2 protein is capable of eliciting high titer antibody production in mice.