• BMB Reports
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• v.53 no.8
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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.

• Journal of fish pathology
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• v.23 no.1
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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.

• Journal of Veterinary Clinics
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• v.8 no.1
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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.

• YAKHAK HOEJI
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• v.31 no.2
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• pp.126-132
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• 1987

Polysaccharide fraction isolated from Coriolus versicolor (Copolang) was studied on the antitumor activity and immunostimulation activities with reference to PS-K. Copolang showed nearly equal antitumor activities to the PS-K and exhibited marked augmentation effects on the antibody mediated hypersensitivity reaction, delayed type hypersensitivity reaction and NK-cell activity in tumor bearing mice. But it did not show any noticeable effect on the antibody secreting cell and macrophage function in normal mice. These results indicate that the antitumor activity and immunostimulating effect of Copolang are comparable to those of PS-K.

• Journal of Microbiology and Biotechnology
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• v.20 no.8
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• pp.1179-1184
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• 2010

We report the generation of the first monoclonal antibody that specifically binds to the polysaccharide chitosan. Mice were immunized with a mixture of chitosans, and hybridoma clones were screened for specific binders, resulting in the isolation of a single clone secreting a chitosan-specific IgM, mAbG7. In ELISAs, the antibody could bind to chitosans of varying composition, but demonstrated the highest affinity for chitosans with lower degrees of acetylation (DA) and very poor binding to chitin. We tested the ability of the antibody to bind to chitosan in situ, using preparations of fungal cell walls. Immunofluorescence microscopy confirmed that the antibody bound strongly to the cell walls of fungi with high levels of chitosan, whereas poor staining was observed in those species with cell walls of predominantly chitin or cellulose. The potential use of this antibody for the detection of fungal contamination and the protection of plants against fungal pathogens is discussed.

• Journal of fish pathology
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• v.14 no.2
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• pp.97-102
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• 2001

Olive flounder, Paralichthys olivaceus known as an one of the major aquacultured species in Korea were exposed to cadmium(Cd) with different protocols and analyzed the effects of exposure on the immune response. Antibody levels in sera of the group exposed to Cd(20ppb) by immersion method from 2 weeks before immuniztion with formalinised Edwardsiella tarda(E. tarda) KFE entigen to the end of experiment reached to peak level faster than that of the non-exposed group. After this peaking time the levels decreased much at a faster rate compared to the non-exposed group. This tendency was also appeared in the numbers of specific antibody secreting cells(SASC) analyzed with the enzyme-linked immunospot (ELISPOT)-assay technique in the splenocytes of the experimental groups exposed to Cd with different ways. Interestingly, the group exposed to Cd for 2 weeks before immunization also showed increased numbers of SASC unlikely the antibody production and suggested a more critical influence of cadmium exposure in early stage of immune reaction. Artificial infection with live E. tarda KFE induces 100% mortality in the flounder exposed to cadmium throughout the experimental period from two weeks before the immunization. It may imply that some other factors related to specific immunity are involving in the defence system of flounder exposed to Cd. Taked together. Cd exposure may induce temporaily stimulatory or indhibitory effects on the immune reaction, but suppress the physiological systems for the resistant against the infective agents with other toxic effects.

• Korean Journal of Microbiology
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• v.23 no.1
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• pp.64-68
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• 1985

In this study, hybridoma techniques were applied to produce monoclonal antobodies to Paragonimus westermani, commonly known as lung distoma. Balb/c mice were immunized intraperitoneally every week with increasing doses of purfied protein of Paragonimus westermani adult worms begining with 0.3/mg/mouse/7 days and ending with 0.5mg at 28th day. Spleen cells from these immunized mice were hybridized with myeloma cells (NS-1) and the hybridized cells were selected in HAT media. The antibody secreting cells among the hybrid cells were initially selected by ELISA. Those initially selected cells were further screened by the criteria of antibody producing activity, and seneral cell lines among them were further tested with immunodiffusion method. One hybridoma clone produced IgM and another clone produced IgG1. The supernatant of the hybridoma clone producing IgM had titer 1:64 and the hybridoma clone producing IgG1 had titer 1:256 measured by immunofluorescence technique.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.4
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• pp.420-426
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• 1999

We examined the immune response in flounder, Paralichthys olivaceus, with immunization of formalin killed Edwardsiella tarda as an antigen. The ELISPOT-assay (enzyme-linked immunospot assay) was optimized technically and applied to count the number of total and specific antibody secreting cells (TASC and SASC) in lymphocytes of different lymphatic organs. Incubation of lymphocytes on 96 well plate for more than 2.5hrs came out enough time in ELISPOT-assay for counting the antibody secreting cells in the anterior kidney and spleen. However, too much of plate-coated antigen or rabbit anti-flounder immunoglobulin for SASC or TASC counting, respectively, was appeared to decrease the sensitivity of the assay system. Specificity of the system was also confirmed by the absence of TASC in lymphocytes treated with cycloheximide to prevent protein synthesis. The peak numbers of SASC appeared at wk 3 post immunization after that there was a sharp decrease and reached to almost zero at wk 7. In the spleen and kidney, the timing and numbers of SASC on peak response were concurrent without preferential organ distribution. The specific antibody level in the sera increased rapidly between wk 2 and 3 after immunization, i.e. like the specific cellular response found with ELISPOT-assay on that period, However, the remained high level of specific serum antibody from wk 5 after immunization until the end of experiment was clearly distinguishable from the kinetics of SASC response decreased sharply.

• YAKHAK HOEJI
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• v.31 no.5
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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.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2001.11a
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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.