악성 B림프종 CH12.LX는 정상적인 마우스 B세포와 유사하게 Lipopolysaccharide와 transforming Growth factor-β1에 대해 반응

김평현 江原大學校 遺傳工學硏究所 1994 生命科學硏究論叢 Vol.12 No.-

IgA 항체합성에 대한 초유함유 TGF- β 와 bifidobacteria의 영향 평가

김평현,고준수 한국축산식품학회 2001 심포지움 및 학술발표회 Vol.- No.28

Colostrum contains various kinds of cytokines including TGF-β which is known to be multifunctional in immune response and act as an anti-inflammatory agent. First, we measured the amount of TGF-β in bovine and human colostrum. Expression pattern of TGF-β isotypes was dramatically different between human and bovine colostrial samples. Bovine colostrum collected on day 1 post-delivery retained 41.79×16.96ng/ml of TGF-β 1 and 108.4±78.65ng/ml of TGF-β 2 while in human, 284±124.75ng/ml of TGF-β 1 and 29.75±6.73ng/ml of TGF-β 2. Thus, TGF-β is the predominant TGF-β isotype in bovine colostrum and vice versa in human colostrum. Both TGF-β 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-β 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-β 1 and anti-TGF-β 2 antibody. In conclusion, there are substantial amounts of biologically active TGF-β 1 and TGF-β 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.

Activin A Stimulates Mouse APCs to Express BAFF via ALK4-Smad3 Pathway

김재희,김평현,서구영 대한면역학회 2011 Immune Network Vol.11 No.4

Background: B cell-activating factor belonging to the TNF family (BAFF) is primarily expressed by macrophages and dendritic cells, and stimulates B cell proliferation, differentiation, survival, and Ig production. In the present study, we explored the effect of activin A on BAFF expression by APCs. Methods: To investigate the effect of activin A on BAFF expression by mouse APCs, we measured the level of BAFF expression at the transcriptional and protein levels using RT-PCR and ELISA. Results: Activin A markedly enhanced BAFF expression in mouse macrophages and dendritic cells at both the transcriptional and protein levels. SB431542, an activin receptor-like kinase 4 (ALK4) inhibitor, completely abrogated activin A-induced BAFF transcription. Furthermore, overexpression of DN-Smad3 abolished activin-induced BAFF expression at the transcriptional and protein levels. Conclusion: These results demonstrate that activin A can enhance BAFF expression through ALK4-Smad3 pathway.

SUMO Proteins are not Involved in TGF-β1-induced, Smad3/4-mediated Germline α Transcription, but PIASy Suppresses it in CH12F3-2A B Cells

이상훈,김평현,오상묵,박정환,유영춘,이정림,박석래 대한면역학회 2014 Immune Network Vol.14 No.6

TGF-β induces IgA class switching by B cells. We previouslyreported that Smad3 and Smad4, pivotal TGF-β signal-transducing transcription factors, mediate germline (GL)α transcription induced by TGF-β1, resulting in IgA switchingby mouse B cells. Post-translational sumoylation ofSmad3 and Smad4 regulates TGF-β-induced transcriptionalactivation in certain cell types. In the present study, we investigatedthe effect of sumoylation on TGF-β1-induced,Smad3/4-mediated GLα transcription and IgA switching bymouse B cell line, CH12F3-2A. Overexpression of small ubiquitin-like modifier (SUMO)-1, SUMO-2 or SUMO-3 did notaffect TGF-β1-induced, Smad3/4-mediated GLα promoteractivity, expression of endogenous GLα transcripts, surfaceIgA expression, and IgA production. Next, we tested the effectof the E3 ligase PIASy on TGF-β1-induced, Smad3/4-mediated GLα promoter activity. We found that PIASy overexpressionsuppresses the GLα promoter activity in cooperationwith histone deacetylase 1. Taken together, these resultssuggest that SUMO itself does not affect regulation ofGLα transcription and IgA switching induced by TGF-β1/Smad3/4, while PIASy acts as a repressor.

Sensitivity of Pseudomonas syringae to Bovine Lactoferrin Hydrolysates and Identification of a Novel Inhibitory Peptide

김완섭,김평현,Kei-ichi Shimazaki 한국축산식품학회 2016 한국축산식품학회지 Vol.36 No.4

The antimicrobial activity of bovine lactoferrin hydrolysates (bLFH) was measured against Pseudomonas strains (P. syringae and P. fluorescens) in vitro. To compare susceptibility to bLFH, minimal inhibitory concentration (MIC) values were determined using chemiluminescence assays and paper disc plate assays. Antimicrobial effect against P. fluorescens was not observed by either assay, suggesting that bLFH did not exhibit antimicrobial activity against P. fluorescens. However, a significant inhibition of P. syringae growth was observed in the presence of bLFH. The addition of bLFH in liquid or solid medium inhibited growth of P. syringae in a dose-dependent manner. Furthermore, a bLFH peptide with antimicrobial activity toward P. syringae was isolated and identified. The N-terminal amino acid sequences of thus obtained antimicrobial bLFH peptides were analyzed by a protein sequencer and were found to be Leu-Arg-Ile-Pro-Ser-Lys-Val-Asp-Ser-Ala and Phe-Lys-Cys-Arg-Arg-Trp-Gln-Trp-Arg-Met. The latter peptide sequence is known to be characteristic of lactoferricin. Therefore, in the present study, we identified a new antimicrobial peptide against P. syringae, present within the N-terminus and possessing the amino acid sequence of Leu-Arg-Ile-Pro-Ser-Lys-Val-Asp-Ser-Ala.

수정난내의 세포질의 재배치가 발생에 미치는 영향: 양서류난의 역위와 난할양상의 관계

정해문,김평현,김덕희 한국통합생물학회 1983 동물학회지 Vol.26 No.3

양서류 초기발생기작을 밝히기 위하여 참개구리와 산개구리의 수정난을 재료로 수정 이후 제 1분열 사이를 여러 등분하여 $180^\\circ$ 역위시켰다. 역위에 대한 반응은 종에 따라 매우 달라서 제1난할면과 난할양상의 차이가 현저하였다. 참개구리 역위난이 중력의 반대방향인 원래의 식물극에서 제1분열ㅇ이 시작되어 동물극쪽으로 진행된 반면, 산개구리 역위난은 정상난과 마찬가지로 원래의 동물극에서 제1분열면이 관찰되었다. 난할양상도 매우 달라서 참개구리 역위난의 경우 식물반구의 할구들이 동물반구의 것에 비해 훨씬 작게 뒤바뀌어 나타난 반면, 산개구리의 경우는 난할양상이 거의 변하지 않고 정상난과 동일하였다. 역위난의 조직학적 검사에 의하면 역위에 대한 반응이 종에 따라 상이한 이유는 핵과 난황립과 같은 수정난의 내용물의 재배치가 일어나는 정도가 다른 데 기인하는 것으로 사료된다. Inversion at variable time of the uncleaved eggs of Rana nigromaculata and Rana dybowskii was emplyed to study the mechanisms of early embryogenesis. The response to inversion varied between those two spcies. If the eggs were inverted at early time it was possible to change the site of the first cleavage furrow of Rana nigromaculata-it appeared on the original vegetal hemisphere (OpG side). However, the first cleavage furrow of Rana dybowskii was not changed at all no matter what its inversin time was-it always appeared on the original animal hemisphere (G. side). In the inverted Rana nigromaculata embryos the size of the blastomeres on the vegetal hemisphere was always smaller than those of animal hemisphere. On the ocntrary, the cleavage pattern of Rana dybowskii was not altered. Results of the histological works for the inverted eggs suggest that the different responses to inversion might be caused by the fact that the extent to which the redistribution of the egg components such as cleavage nuclei and yolk platelets are different.

Further Characterization of Activin A-induced IgA Response in Murine B Lymphocytes

이화정,김평현 대한면역학회 2009 Immune Network Vol.9 No.4

We have recently shown that activin A, a member of TGF-β superfamily, stimulates mouse B cells to express IgA isotype but other isotypes. In the present study, we further characterized effects of activin A on B cell growth and IgA expression. We found that activin A did not have effect on LPS-stimulated cell viability. In parallel, CFSE staining analysis revealed that activin A did not alter cell division. An increase of IgA secretion by activin A was completely abrogated by anti-activin A Ab but not by anti-TGFβ1 Ab. In the same conditions, no other isotypes are significantly affected by each antibody treatment. Finally, activin A, as similar to TGF-β1, increased IgA secretion by mesenteric lymph node cells. These results suggest that activin A can specifically stimulate IgA response, independent of TGF-β in the gut. We have recently shown that activin A, a member of TGF-β superfamily, stimulates mouse B cells to express IgA isotype but other isotypes. In the present study, we further characterized effects of activin A on B cell growth and IgA expression. We found that activin A did not have effect on LPS-stimulated cell viability. In parallel, CFSE staining analysis revealed that activin A did not alter cell division. An increase of IgA secretion by activin A was completely abrogated by anti-activin A Ab but not by anti-TGFβ1 Ab. In the same conditions, no other isotypes are significantly affected by each antibody treatment. Finally, activin A, as similar to TGF-β1, increased IgA secretion by mesenteric lymph node cells. These results suggest that activin A can specifically stimulate IgA response, independent of TGF-β in the gut.

Effect of Transforming Growth Factor - β1 , IL - 2 and IL - 10 on the Synthesis of Immunoglobulins in Human B Cells

이정희,김평현,박영의,이민철 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1994 한국미생물생명공학회 학술발표초록집 Vol.1994 No.1

Macrophage - Derived Transforming Growth Factor - β1 Enhances IgA Isotype Secretion by LPS - Activated Murine B Cells

민경미,김평현 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1994 한국미생물생명공학회 학술발표초록집 Vol.1994 No.1

Newly Identified TLR9 Stimulant, M6-395 Is a Potent Polyclonal Activator for Murine B Cells

박미희,김평현,정유진 대한면역학회 2012 Immune Network Vol.12 No.1

Background: Toll-like receptors (TLRs) have been extensively studied in recent years. However, functions of these molecules in murine B cell biology are largely unknown. A TLR4stimulant, LPS is well known as a powerful polyclonal activator for murine B cells. Methods: In this study, we explored the effect of a murine TLR9 stimulant, M6-395 (a synthetic CpG ODNs) on B cell proliferation and Ig production. Results:First, M6-395 was much more potent than LPS in augmenting B cell proliferation. As for Ig expression, M6-395 facilitated the expression of both TGF-β1-induced germ line transcript α (GLTα) and IL-4-induced GLTγ1 as levels as those by LPS and Pam3CSK4 (TLR1/2 agonist) : a certain Ig GLT expression is regarded as an indicative of the corresponding isotype switching recombination. However, IgA and IgG1 secretion patterns were quite different--these Ig isotype secretions by M6-395 were much less than those by LPS and Pam3CSK4. Moreover, the increase of IgA and IgG1 production by LPS and Pam3CSK4 was virtually abrogated by M6-395. The same was true for the secretion of IgG3. We found that this unexpected phenomena provoked by M6-395 is attributed, at least in part, to its excessive mitogenic nature. Conclusion: Taken together, these results suggest that M6-395 can act as a murine polyclonal activator but its strong mitogenic activity is unfavorable to Ig isotype switching.