우리는 도움이 토론에 대한 마틴의 실험실에 감사하고 있습니다. 이 책자는 건강 연구의 캐나다 연구소 (걸레 - 89783)에서 부여로 지원됩니다. AM은 캐나다 연구 의자 티어 II 수상에 의해 지원됩니다.

단계 I : 자기 강화를 통해 지라 B 세포의 절연 <ol><li> 실험 생쥐는 면역 체계의 전체 성숙을 보장하기 위해 8~12주 이상되어야합니다. </li><li> 자궁 경부 전위로 마우스를 안락사와 70 % 에탄올에서 만끽해보세요. 수술 복부의 왼쪽 hypochondrium의 피부와 근육을 통해 절개하여 비장을 제거하고 인산의 3 대 조각으로 잘라 (PBS) 살린 버퍼. 모든 도구와 시약은 멸균 수 있도록. </li><li> 부드럽게 매쉬는 PBS로 70 μm의 셀 스트레이너를 통해 1 ML 주사기 플런저의 고무 끝을 비장 사용합니다. 연삭가 큰 (proliferating 예) 세포의 파열로 이어질 수 있으므로 추진 운동보다는 연삭 모션을 사용해야합니다. </li><li> 5 분 더 이상 350 이상 g에서 세포를 스핀 다운 및 PBS의 펠렛을 resuspend. hemocytometer를 사용하여 resuspended 세포를 계산합니다. </li><li> 뚜껑이있는 멸균 5 ML의 폴리스티렌 튜브 5% 정상 쥐의 혈청 (튜브 당 2 ML 최대 볼륨)과 1x10 8 셀 / PBS에 ML의 정지를 준비합니다. </li><li> 세포의 모든 ML에 대한 부정적 EasySep 선택 마우스 B 세포 농축 칵테일 50 μL를 추가합니다. 혼합물을 피펫, 튜브 캡, 15 분 동안 냉장고에 곳입니다. </li><li> 세포의 모든 ML 100 μL EasySep 비오틴 선택 칵테일을 추가합니다. 혼합물을 피펫, 튜브 캡, 15 분 동안 냉장고에 곳입니다. </li><li> 세포의 모든 ML에 대한 EasySep 마그네틱 Nanoparticles 100 μL를 (nanoparticles 잘 혼합되고 솔루션은 동질한지) 추가합니다. 혼합물을 피펫, 튜브 캡, 5 분 동안 냉장고에 곳입니다. </li><li> PBS로 5 분 EasySep 자석의 장소 2.5mL 위로는 솔루션입니다. 자석과 튜브를 반전하고 새로운 폴리스티렌 튜브에 신속하게 부어. 부정적인 선택 세포가 자기 (磁 气) 튜브 벽에 바인딩되므로 튜브를 흔들지 마세요. </li><li> 더욱 세포 현탁액의 순도를 높이려면, 튜브가 추가 5 분 자석에 다시 삽입하고 새로운 튜브로 부어있을 수 있습니다. 이것은 전체 세포 복구를 줄일 수 있습니다. </li><li> B 세포의 순도는 B 세포 표면 마커의 흐름 cytometric 분석에 의해 평가하실 수 있습니다. 농축 다음, 우리는 지속적으로&gt; 95% B220 긍정적인 세포의 순도를 참조하십시오. </li></ol> CFSE 세포 얼룩 : II 단계 <ol><li> ML 당 1 × 10 6 세포의 최종 농도에서 알부민 0.1 % 소 혈청과 보충 따뜻한 PBS에서 분리된 세포를 Resuspend. </li><li> CFSE (무균 디메틸 sulfoxide에 희석)의 5mM 재고 솔루션을 준비하고 튜브에 세포의 모든 ML에 대한 2μL를 추가합니다. 10μM의 최종 농도는 기본 B 세포의 얼룩에 최적입니다. </li><li> 37 품어 ° 어둠 속에서 10 분 동안 C (참고 : CFSE 빛을 민감한하고 가능하면 어둠에 보관한다.) </li><li> 당신의 세포에 소 송아지 혈청의 동일한 볼륨을 추가하고 5 분 얼음 잠복기로 얼룩을 끄다. </li><li> G.를 (제조법 단계 III 참조) 문화 매체로 튜브를 토핑하고 350에 centrifuging하여 세포 와시 미디어 적어도 5 배 부피 상응하는이 소 송아지 혈청의 점도를 중화하고 세포의 펠렛 생산에 추가할 수 있어야합니다. </li><li> 문화 매체에 두 번 더 세포를 씻으십시오. 세포는 이제 자극에 대한 준비가되어 있습니다. </li></ol> III 단계 : LPS와 함께 세포 자극을 <ol><li> 10% 소태아 혈청 및 50 μm의 β - 메르 캅 토 에탄올 /로 RPMI 1640을 보완하여 체외의 B 세포 배양 매체에서를 준비합니다. </li><li> 50μg/mL의 최종 농도에서 LPS를 추가하여 자극 미디어를 준비합니다. 평평한 바닥의 각 잘 96 - 웰 조직 배양 플레이트에 자극을 매체의 나누어지는 125 μL. </li><li> 3.2 X 10 6 세포 / ML의 최종 농도에서 LPS없는 배지에서 CFSE - 스테인드 B 전지를 준비합니다. 귀하의 자극 미디어 부드럽게 pipetting으로 혼합을 포함하고있는 우물에 세포 현탁액 125 μL를 추가합니다. </li><li> 각 물론 지금은 25 μg / ML의 최종 LPS 농도 4 X 10 5 세포가 포함되어 있습니다. 이러한 값을 변경을 원하는대로 만들 수 있지만 이것은 세포 증식 및 클래스 스위칭의 최적 수준을 제공합니다. </li><li> 37 세포를 품어 ° C와 5% 72~96시간에 대한 CO 2. 48 시간 후, 큰 proliferating B 세포의 클러스터는 현미경으로 명확하게 볼 수 있습니다. </li></ol> 단계 IV : 클래스 스위칭의 흐름 cytometric 분석 <ol><li> 이 클래스 스위칭 볼 준비가되면, 그들의 문화 조건에서 세포를 제거하고 얼룩 버퍼 (2 % 소 송아지 혈청 PBS) 1 ML 두 번 그들을 씻으십시오. </li><li> 350g과 incuba에서 그들을 회전하여 세포 펠릿 세포가 아닌 특정 항체 얼룩을 방지하기 위해5% 정상 마우스 혈청 얼음에 15 분 동안 FcBlock per106 세포의 1μg과 버퍼를 얼룩의 100μL에 테 그들. 셀 차단은 얼음에서 수행되어야합니다. </li><li> 당신의 세포를 세척하지 않고, 찬란 태그를 방지 마우스 IgG3 항체의 10 6 세포 당 1μg을 추가하고 세포가 얼음에 30 분 동안 착색 수 있습니다. </li><li> 얼룩 버퍼의 200-300 μL에서 원심 분리하고 resuspend에 의해 두 번 세포를 씻으십시오. 세포는 이제 유동세포계측법에 의해 평가를위한 준비가되어 있습니다. </li><li> CFSE는 최적의 492 nm의에서 흥분 (아르곤 이온 레이저로)와 517 nm의에서 방출됩니다. IgG3 항체의 여기 및 발광 스펙트럼은 형광 염료 공액에 따라 달라집니다. </li></ol> 대표 결과 자기 강화에 따라 세포 현탁액은 분간 작은 원형 세포 (그림 1A)의 동질적인 인구처럼 보이게한다. 자극 48~72시간 후, 확대 proliferating 세포의 격리 클러스터 (그림 1B) 명확하게 볼 수 있습니다. 그들은 apoptosis를 받아야 같은 비 - proliferating 세포의 큰 비율은 작은 입상 나타납니다. 세포의 대부분 7 죽기 시작하기 전에 CSR은 일반적으로 자극 후 72 96시간 사이에서 가장 높은 수준에서 검색하실 수 있습니다. 이 단계에서, 세포는 나중에 딸 세포 인구에 나타나는 전환 세포와 세포 분열의 번호를받은 것입니다. CFSE 희석과 LPS의 자극 96 시간 후 IgG3의 표면 표현의 대표적인 흐름 cytometric 플롯은 그림 2에서 볼 수 있습니다. 표 1. 칵테일 스위칭 Isotype. 참고 : 흥분제 농도 값은 권장 사항입니다. Titrations가 필요할 수 있습니다. <table border="1"><tbody><tr><td> 원하는 Isotype </td><td> 자극 칵테일 </td></tr><tr><td> IgG1and IGE </td><td> LPS (25μg/mL)와 IL - 4 (10 NG / ML) </td></tr><tr><td> IgG1and IGE </td><td> 안티 CD40 (10μg/mL)와 IL - 4 (10 NG / ML) </td></tr><tr><td> IgG2a </td><td> LPS (25μg/mL)와 IFN - γ (10 NG / ML) </td></tr><tr><td> IgG2b 및 IgG3 </td><td> LPS (25μg/mL) </td></tr><tr><td> 이가 </td><td> LPS (25μg/mL), TGF - β (2 NG / ML)와 IL - 5 (1.5 NG / ML) </td></tr></tbody></table><img src="/files/ftp_upload/2130/2130fig1.jpg" alt="그림 1" /> 그림 1. 지라 분리 및 B 세포의 LPS의 자극. (A) 자기 (磁 气) LPS의 자극 전 지라 B 세포를 풍부하게. (B) 48시간 25 μg / LPS의 ML과 자극 후. Proliferating 세포 가공 및 apoptotic 세포의 배경에 클러스터로 볼 수 있습니다. <img src="/files/ftp_upload/2130/2130fig2.jpg" alt="그림 2" /> 그림 2. 96시간 후 확산 및 클래스 스위치 재조합. (A) LPS에 대한 CFSE 희석은 문화에 96시간 후 세포를 자극. 각각의 독립적인 피크는 독립적인 세포 분열에 대응하는 CFSE의 형광에 희석을 나타냅니다. (B) IgG3 표현은 세포 분열의 여러 순찰 다음 IgG3 긍정적인 인구의 출현을 보여주는.

<ol>
	<li>Hodgkin, P. D., Lee, J. H., Lyons, A. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=B+cell+differentiation+and+isotype+switching+is+related+to+division+cycle+number.">B cell differentiation and isotype switching is related to division cycle number.</a> J Exp Med. 184, 277-281 (1996).</li><li>McCall, M. N., Hodgkin, P. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Switch+recombination+and+germ-line+transcription+are+division-regulated+events+in+B+lymphocytes.">Switch recombination and germ-line transcription are division-regulated events in B lymphocytes.</a> Biochim Biophys Acta. 1447, 43-50 (1999).</li><li>Manis, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=53BP1+links+DNA+damage-response+pathways+to+immunoglobulin+heavy+chain+class-switch+recombination.">53BP1 links DNA damage-response pathways to immunoglobulin heavy chain class-switch recombination.</a> Nat Immunol. 5, 481-487 (2004).</li><li>de Yebenes, V. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=miR-181b+negatively+regulates+activation-induced+cytidine+deaminase+in+B+cells.">miR-181b negatively regulates activation-induced cytidine deaminase in B cells.</a> J Exp Med. 205, 2199-2206 (2008).</li><li>McBride, K. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulation+of+class+switch+recombination+and+somatic+mutation+by+AID+phosphorylation.">Regulation of class switch recombination and somatic mutation by AID phosphorylation.</a> J Exp Med. 205, 2585-2594 (2008).</li><li>Ramachandran, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+RNF8/RNF168+ubiquitin+ligase+cascade+facilitates+class+switch+recombination.">The RNF8/RNF168 ubiquitin ligase cascade facilitates class switch recombination.</a> Proc Natl Acad Sci U S A. 107, 809-8014 (2010).</li><li>Zaheen, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=AID+constrains+germinal+center+size+by+rendering+B+cells+susceptible+to+apoptosis.">AID constrains germinal center size by rendering B cells susceptible to apoptosis.</a> Blood. 114, 547-554 (2009).</li><li>Chaudhuri, J., Alt, F. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Class-switch+recombination:+interplay+of+transcription,+DNA+deamination+and+DNA+repair.">Class-switch recombination: interplay of transcription, DNA deamination and DNA repair.</a> Nat Rev Immunol. 4, 541-552 (2004).</li><li>Kaminski, D. A., Stavnezer, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stimuli+that+enhance+IgA+class+switching+increase+histone+3+acetylation+at+S+alpha,+but+poorly+stimulate+sequential+switching+from+IgG2b.">Stimuli that enhance IgA class switching increase histone 3 acetylation at S alpha, but poorly stimulate sequential switching from IgG2b.</a> Eur J Immunol. 37, 240-251 (2007).</li><li>Kaminski, D. A., Stavnezer, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antibody+class+switching+differs+among+SJL,+C57BL/6+and+129+mice.">Antibody class switching differs among SJL, C57BL/6 and 129 mice.</a> Int Immunol. 19, 545-556 (2007).</li></ol>

관심 없음 충돌 선언하지 않습니다.

위에서 설명한 프로토콜은 기본 murine B 세포의 클래스 스위칭하는 동안 보조 표현과 기능을 분석하기위한 표준 분석을 제공합니다. 자극 미디어에 수정이 다른 isotypes (표 1 8, 9에 요약)으로 전환 유도하기 위해 만들 수 있지만이 프로토콜은, IgM에서 IgG3로 전환 유발하는 박테리아 LPS를 사용합니다. 우리는 아직 알려지지 않은 이유로, 태아 송아지 혈청 클래스 체외에?...

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		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Phosphate Buffered Saline</td>
<td>&nbsp;</td>
<td>Gibco</td>
<td>14190</td>
<td>&nbsp;</td>
<tr>
<td>EasySep Mouse B Cell Enrichment Kit</td>
<td>&nbsp;</td>
<td>Stemcell Technologies</td>
<td>19754</td>
<td>&nbsp;</td>
<tr>
<td>Polystyrene tubes</td>
<td>&nbsp;</td>
<td>Becton Dickinson Falcon</td>
<td>352058</td>
<td>&nbsp;</td>
<tr>
<td>Bovine Serum Albumin</td>
<td>&nbsp;</td>
<td>Sigma Aldrich</td>
<td>A7030</td>
<td>&nbsp;</td>
<tr>
<td>CellTrace CFSE Cell Proliferation Kit</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>C34554</td>
<td>&nbsp;</td>
<tr>
<td>Bovine Calf Serum</td>
<td>&nbsp;</td>
<td>HyClone</td>
<td>SH30072.03</td>
<td>&nbsp;</td>
<tr>
<td>RPMI 1640 Culture Medium</td>
<td>&nbsp;</td>
<td>Gibco</td>
<td>11875</td>
<td>&nbsp;</td>
<tr>
<td>Lipopolysaccharides from Escherichia coli</td>
<td>&nbsp;</td>
<td>Sigma Aldrich</td>
<td>L6529</td>
<td>&nbsp;</td>
<tr>
<td>&beta;-mercaptoethanol</td>
<td>&nbsp;</td>
<td>Gibco</td>
<td>21985</td>
<td>&nbsp;</td>
<tr>
<td>Fetal Bovine Serum</td>
<td>&nbsp;</td>
<td>HyClone</td>
<td>SH30396.03</td>
<td>&nbsp;</td>
<tr>
<td>Normal Mouse Serum</td>
<td>&nbsp;</td>
<td>Jackson ImmunoResearch</td>
<td>011-000</td>
<td>&nbsp;</td>
<tr>
<td>Purified Rat Anti-Mouse CD16/CD32 (Mouse BD Fc Block)</td>
<td>&nbsp;</td>
<td>Becton Dickinson Pharmingen</td>
<td>553141</td>
<td>&nbsp;</td>
<tr>
<td>Rat Anti-Mouse IgG3</td>
<td>&nbsp;</td>
<td>Becton Dickinson Pharmingen</td>
<td>553401</td>
<td>&nbsp;</td>		</tbody>
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induction and assessment of class switch recombination in purified murine b cells

체액성 면역은 B 세포에 의해 유지 및 항체의 분비를 통해 중재 면역 시스템의 지점이다. B 세포 활성화되면 면역 글로불린 로커스는 바인딩 용량과 분비 항체의 이펙터 기능을 변경하는 유전자 수정 일련의를 겪습. 이 프로세스는 기본 IgM 항체의 isotype은 IgG, 이가, 또는 IGE 중 하나에 대체되는 클래스 스위치 재조합 (CSR)으로 알려진 게놈 재조합 이벤트로 강조 표시됩니다. 각 isotype되므로 면역의 유지 관리 CSR은 중요하고 독특한 이펙터 기능을 가지고 있습니다. 면역 글로불린 로커스의 다변화는 효소 활성 유발 cytidine deaminase의 (AID)에 의해 중재됩니다. 자세히이 과정을 설명하는 도식 동영상은 온라인 (http://video.med.utoronto.ca/videoprojects/immunology/aam.html)입니다. AID의 활동 및 CSR의 경로는 일반적으로 B 세포 기능과 마우스의 체액성 면역의 평가에서 공부하고 있습니다. 이 보고서에 제시된 프로토콜은 murine spleens와 클래스 (다른 항체 isotypes에 대한 표 1 참조) IgG3로 전환 유발하는 박테리아 lipopolysaccharide (LPS)와 후속 자극에서 B 세포 분리의 방법을 보여줍니다. 또한, 형광 세포 염색 얼룩 Carboxyfluorescein succinimidyl 에스테르 (CFSE)를 자극 세포의 세포 분열, 스위칭 1, 2 isotype에 중요한 프로세스를 모니터하는 데 사용됩니다. 구호품과 CSR이 발생하는 메커니즘의 규정은 아직 불분명하고 있으므로 체외 클래스 스위치 assays 다양한 마우스 모델에서 이러한 프로세스를 테스트하기위한 신뢰할 수있는 방법을 제공합니다. 이러한 assays는 이전에 다음 ID로 녹아웃 마우스 3를 사용하여 유전자 결핍의 맥락에서 사용되었습니다. 또한, 관내는 B 세포의 스위칭 RNA의 분해 또는 transgene 표현 4-6에 의해 유전자 발현을 조절하는 바이러스 전달 앞에 수 있습니다. 실험 이러한 종류의 데이터는 구호 활동, CSR 반응의 해상도 및 마우스에서 항체 - 매개 면역에 대한 우리의 이해에 영향을합니다.

Watch this Scientific Journal Video about Induction and Assessment of Class Switch Recombination in Purified Murine B Cells at JoVE.com

Induction and Assessment of Class Switch Recombination in Purified Murine B Cells

항원 노출에 따라 활성화된 B 세포의 subpopulations는 독특한 효과기 기능 항체 isotypes를 만들어 클래스 스위치 재조합 (CSR)으로 알려진 공정을 받고있다. 이 보고서에 제시된 프로토콜은 CSR을 유도하고 분석하는 방법을 설명합니다<em&gt; 체외에서</em&gt; B 세포 기능을 공부 목적.

Murine B 세포를 정화에 유도 및 클래스 스위치 재조합 평가

Humoral immunity is the branch of the immune system maintained by B cells and mediated through the secretion of antibodies. Upon B cell activation, the ...

induction-assessment-class-switch-recombination-purified-murine-b

Research

JoVE Journal

Immunology and Infection

18.0K 조회수.  University of Toronto. 항원 노출에 따라 활성화된 B 세포의 subpopulations는 독특한 효과기 기능 항체 isotypes를 만들어 클래스 스위치 재조합 (CSR)으로 알려진 공정을 받고있다. 이 보고서에 제시된 프로토콜은 CSR을 유도하고 분석하는 방법을 설명합니다 체외에서 B 세포 기능을 공부 목적.

비디오: Induction and Assessment of Class Switch Recombination in Purified Murine B Cells

Murine Model of CD40-activation of B cells

Research on B cells has shown that CD40 activation improves their antigen presentation capacity. When stimulated with interleukin-4 and CD40 ligand (CD40L), human B cells can be expanded without difficulties from small amounts of peripheral blood within 14 days to very large amounts of highly-pure CD40-B cells (&gt;109 cells per patient) from healthy donors as well as cancer patients1-4. CD40-B cells express important lymph node homing molecules and can attract T cells in vitro5. Furthermore they efficiently take up, process and present antigens to T cells6,7. CD40-B cells were shown to not only prime na&iacute;ve, but also expand memory T cells8,9. Therefore CD40-activated B cells (CD40-B cells) have been studied as an alternative source of immuno-stimulatory antigen-presenting cells (APC) for cell-based immunotherapy1,5,10. In order to further study whether CD40-B cells induce effective T cell responses in vivo and to study the underlying mechanism we established a cell culture system for the generation of murine CD40-activated B cells. Using splenocytes or purified B cells from C57BL/6 mice for CD40-activation, optimal conditions were identified as follows: Starting from splenocytes of C57BL/6 mice (haplotype H-2b) lymphocytes are purified by density gradient centrifugation and co-cultured with HeLa cells expressing recombinant murine CD40 ligand (tmuCD40L HeLa)11. Cells are recultured every 3-4 days and key components such as CD40L, interleukin-4, -Mercaptoethanol and cyclosporin A are replenished. In this protocol we demonstrate how to obtain fully activated murine CD40-B cells (mCD40B) with similar APC-phenotype to human CD40-B cells (Fig 1a,b). CD40-stimulation leads to a rapid outgrowth and expansion of highly pure (&gt;90%) CD19+ B cells within 14 days of cell culture (Fig 1c,d). To avoid contamination with non-transfected cells, expression of the murine CD40 ligand on the transfectants has to be controlled regularly (Fig 2). Murine CD40-activated B cells can be used to study B-cell activation and differentiation as well as to investigate their potential to function as APC in vitro and in vivo. Moreover, they represent a promising tool for establishing therapeutic or preventive vaccination against tumors and will help to answer questions regarding safety and immunogenicity of this approach12.

In this video, we demonstrate the procedure of CD40-activation and expansion of murine B cells from splenocytes of C57BL/6 mice, which can be used as a model antigen-presenting cell (APC) to study induction of immunity.

B 세포의 CD40 - 정품 인증 Murine 모델

Research on B cells has shown that CD40 activation improves their antigen presentation capacity. When stimulated with interleukin-4 and CD40 ligand ...

연구

면역학 및 감염병학

Identifying DNA Mutations in Purified Hematopoietic Stem/Progenitor Cells

In recent years, it has become apparent that genomic instability is tightly related to many developmental disorders, cancers, and aging. Given that stem cells are responsible for ensuring tissue homeostasis and repair throughout life, it is reasonable to hypothesize that the stem cell population is critical for preserving genomic integrity of tissues. Therefore, significant interest has arisen in assessing the impact of endogenous and environmental factors on genomic integrity in stem cells and their progeny, aiming to understand the etiology of stem-cell based diseases.
LacI transgenic mice carry a recoverable &#955;&#160;phage vector encoding the LacI reporter system, in which the LacI gene serves as the mutation reporter. The result of a mutated LacI gene is the production of &#946;-galactosidase that cleaves a chromogenic substrate, turning it blue. The LacI reporter system is carried in all cells, including stem/progenitor cells and can easily be recovered and used to subsequently infect E. coli. After incubating infected E. coli on agarose that contains the correct substrate, plaques can be scored; blue plaques indicate a mutant LacI gene, while clear plaques harbor wild-type. The frequency of blue (among clear) plaques indicates the mutant frequency in the original cell population the DNA was extracted from. Sequencing the mutant LacI gene will show the location of the mutations in the gene and the type of mutation.
The LacI transgenic mouse model is well-established as an in vivo mutagenesis assay. Moreover, the mice and the reagents for the assay are commercially available. Here we describe in detail how this model can be adapted to measure the frequency of spontaneously occurring DNA mutants in stem cell-enriched Lin-IL7R-Sca-1+cKit++(LSK) cells and other subpopulations of the hematopoietic system.

Here we describe an in vivo mutagenesis assay for small numbers of purified hematopoietic cells using the LacI transgenic mouse model.&#160;The LacI gene can be isolated to determine the frequency, location, and type of DNA mutants&#160;spontaneously arisen or after exposure to genotoxins.

정제 된 조혈 줄기 / 전구 세포에 DNA 돌연변이를 확인

In recent years, it has become apparent that genomic instability is tightly related to many developmental disorders, cancers, and aging. Given that stem ...

Detection of True IgE-expressing Mouse B Lineage Cells

B lymphocyte immunoglobulin heavy chain (IgH) class switch recombination (CSR) is a process wherein initially expressed IgM switches to other IgH isotypes, such as IgA, IgE and IgG. Measurement of IgH CSR in vitro is a key method for the study of a number of biologic processes ranging from DNA recombination and repair to aspects of molecular and cellular immunology. In vitro CSR assay involves the flow cytometric measurement surface Ig expression on activated B cells. While measurement of IgA and IgG subclasses is straightforward, measurement of IgE by this method is problematic due to soluble IgE binding to Fc&#949;RII/CD23 expressed on the surface of activated B cells. Here we describe a unique procedure for accurate measurement of IgE-producing mouse B cells that have undergone CSR in culture. The method is based on trypsin-mediated cleavage of IgE-CD23 complexes on cell surfaces, allowing for detection of IgE-producing B lineage cells by cytoplasmic staining. This procedure offers a convenient solution for flow cytometric analysis of CSR to IgE.

In vitro analysis of class switch recombination in mice is challenging due to cytophilic IgE molecules bound to Fc receptors on the surface of B cells. We describe a method for IgE detection using trypsin-mediated cleavage of surface-bound IgE prior to fixation and permeabilization for cytoplasmic fluorescence staining.

진정한 검출 마우스 B 리니지 세포를 IgE 항체가 발현

B lymphocyte immunoglobulin heavy chain (IgH) class switch recombination (CSR) is a process wherein initially expressed IgM switches to other IgH ...

Induction of Murine Intestinal Inflammation by Adoptive Transfer of Effector CD4+CD45RBhigh T Cells into Immunodeficient Mice

There are many different animal models available for studying the pathogenesis of human inflammatory bowel diseases (IBD), each with its own advantages and disadvantages. We describe here an experimental colitis model that is initiated by adoptive transfer of syngeneic splenic CD4+CD45RBhigh T cells into T and B cell deficient recipient mice. The CD4+CD45RBhigh T cell population that largely consists of na&#239;ve effector cells is capable of inducing chronic intestinal inflammation, closely resembling key aspects of human IBD. This method can be manipulated to study aspects of disease onset and progression. Additionally it can be used to study the function of innate, adaptive, and regulatory immune cell populations, and the role of environmental exposures, i.e., the microbiota, in intestinal inflammation. In this article we illustrate the methodology for inducing colitis with a step-by-step protocol. This includes a video demonstration of key technical aspects required to successfully develop this murine model of experimental colitis for research purposes.

Induction of Murine Intestinal Inflammation by Adoptive Transfer of Effector CD4+CD45RBhigh T Cells into Immunodeficient Mice

Here, we present a protocol to induce colonic inflammation in mice by adoptive transfer of syngeneic CD4+CD45RBhigh T cells into T and B cell deficient recipients. Clinical and histopathological features mimic human inflammatory bowel diseases. This method allows the study of the initiation of colonic inflammation and progression of disease.

이펙터 CD4의 입양 전송하여 쥐과 장내 염증의 유도<sup&gt; +</sup&gt; CD45RB<sup&gt; 높은</sup&gt; 면역 결핍 마우스에게 T 세포

There are many different animal models available for studying the pathogenesis of human inflammatory bowel diseases (IBD), each with its own advantages ...

Assessment of the Immunomodulatory Properties of Human Mesenchymal Stem Cells (MSCs)

The immunomodulatory properties of multilineage human mesenchymal stem cells (MSCs) appear to be highly relevant for clinical use towards a wide-range of immune-related diseases. Mechanisms involved are increasingly being elucidated and in this article, we describe the basic experiment to assess MSC immunomodulation by assaying for suppression of effector leukocyte proliferation. Representing activation, leukocyte proliferation can be assessed by a number of techniques, and we describe in this protocol the use of the fluorescent cellular dye carboxyfluorescein succinimidyl ester (CFSE) to label leukocytes with subsequent flow cytometric analyses. This technique can not only assess proliferation without radioactivity, but also the number of cell divisions that have occurred as well as allowing for identification of the specific population of proliferating cells and intracellular cytokine/factor expression. Moreover, the assay can be tailored to evaluate specific populations of effector leukocytes by magnetic bead surface marker selection of single peripheral blood mononuclear cell populations prior to co-culture with MSCs. The flexibility of this co-culture assay is useful for investigating cellular interactions between MSCs and leukocytes.

Assessment of the Immunomodulatory Properties of Human Mesenchymal Stem Cells MSCs

The immunomodulatory properties of human mesenchymal stem cells (MSC) appear increasingly relevant for clinical application. Using a co-culture system of MSCs and peripheral blood leukocytes pre-stained with the fluorescent dye carboxyfluorescein succinimidyl ester (CFSE), we describe the in vitro assessment of MSC immunomodulation on effector leukocyte proliferation and specific subpopulations.

인간 중간 엽 줄기 세포의 면역 속성 (MSCS)의 평가

The immunomodulatory properties of multilineage human mesenchymal stem cells (MSCs) appear to be highly relevant for clinical use towards a wide-range of ...

A Murine Model of Group B Streptococcus Vaginal Colonization

Streptococcus agalactiae (group B Streptococcus, GBS), is a Gram-positive, asymptomatic colonizer of the human gastrointestinal tract and vaginal tract of 10 - 30% of adults. In immune-compromised individuals, including neonates, pregnant women, and the elderly, GBS may switch to an invasive pathogen causing sepsis, arthritis, pneumonia, and meningitis. Because GBS is a leading bacterial pathogen of neonates, current prophylaxis is comprised of late gestation screening for GBS vaginal colonization and subsequent peripartum antibiotic treatment of GBS-positive mothers. Heavy GBS vaginal burden is a risk factor for both neonatal disease and colonization. Unfortunately, little is known about the host and bacterial factors that promote or permit GBS vaginal colonization. This protocol describes a technique for establishing persistent GBS vaginal colonization using a single &#946;-estradiol pre-treatment and daily sampling to determine bacterial load. It further details methods to administer additional therapies or reagents of interest and to collect vaginal lavage fluid and reproductive tract tissues. This mouse model will further the understanding of the GBS-host interaction within the vaginal environment, which will lead to potential therapeutic targets to control maternal vaginal colonization during pregnancy and to prevent transmission to the vulnerable newborn. It will also be of interest to increase our understanding of general bacterial-host interactions in the female vaginal tract.

A Murine Model of Group B Streptococcus Vaginal Colonization

The purpose of this protocol is to imitate human group B Streptococcus (GBS) vaginal colonization in a murine model. This method may be used to investigate host immune responses and bacterial factors contributing to GBS vaginal persistence, as well as to test therapeutic strategies.

그룹 B의 쥐 모델<em&gt; 연쇄상 구균</em&gt; 질 식민

Streptococcus agalactiae (group B Streptococcus, GBS), is a Gram-positive, asymptomatic colonizer of the human gastrointestinal tract and vaginal tract of ...

Genome-wide Analysis of HDAC Inhibitor-mediated Modulation of microRNAs and mRNAs in B Cells Induced to Undergo Class-switch DNA Recombination and Plasma Cell Differentiation

Antibody responses are accomplished through several critical B cell-intrinsic processes, including somatic hypermutation (SHM), class-switch DNA recombination (CSR), and plasma cell differentiation. In recent years, epigenetic modifications or factors, such as histone deacetylation and microRNAs (miRNAs), have been shown to interact with B-cell genetic programs to shape antibody responses, while the dysfunction of epigenetic factors has been found to lead to autoantibody responses. Analyzing genome-wide miRNA and mRNA expression in B cells in response to epigenetic modulators is important for understanding the epigenetic regulation of B-cell function and antibody response. Here, we demonstrate a protocol for inducing B cells to undergo CSR and plasma cell differentiation, treating these B cells with histone deacetylase (HDAC) inhibitors (HDIs), and analyzing mRNA and microRNA expression. In this protocol, we directly analyze complementary DNA (cDNA) sequences using next-generation mRNA sequencing (mRNA-seq) and miRNA-seq technologies, mapping of the sequencing reads to the genome, and quantitative reverse transcription (qRT)-PCR. With these approaches, we have defined that, in B cells induced to undergo CSR and plasma cell differentiation, HDI, an epigenetic regulator, selectively modulates miRNA and mRNA expression and alters CSR and plasma cell differentiation.

Epigenetic factors can interact with genetic programs to modulate gene expression and regulate B cell function. By combining in vitro B-cell stimulation, qRT-PCR, and high-throughput microRNA-sequence and mRNA-sequence approaches, we can analyze the epigenetic modulation of miRNA and gene expression in B cells.

MicroRNAs 받 클래스 스위치 DNA 재조합 및 플라즈마 세포 차별화에 B 세포 유도에서 mRNAs의 게놈 넓은 분석의 HDAC 억제제 중재 변조

Antibody responses are accomplished through several critical B cell-intrinsic processes, including somatic hypermutation (SHM), class-switch DNA ...

In Vitro and In Vivo Assessment of T, B and Myeloid Cells Suppressive Activity and Humoral Responses from Transplant Recipients

The main concern in transplantation is to achieve specific tolerance through induction of regulatory cells. The understanding of tolerance mechanisms requires reliable models. Here, we describe models of tolerance to cardiac allograft in rat, induced by blockade of costimulation signals or by upregulation of immunoregulatory molecules through gene transfer. Each of these models allowed in vivo generation of regulatory cells such as regulatory T cells (Tregs), regulatory B cells (Bregs) or regulatory myeloid cells (RegMCs). In this manuscript, we describe two complementary protocols that have been used to identify and define in vitro and in vivo regulatory cell activity to determine their responsibility in tolerance induction and maintenance. First, an in vitro suppressive assay allowed rapid identification of cells with suppressive capacity on effector immune responses in a dose dependent manner, and can be used for further analysis such as cytokine measurement or cytotoxicity. Second, the adoptive transfer of cells from a tolerant treated recipient to a newly irradiated grafted recipient, highlighted the tolerogenic properties of these cells in controlling graft directed immune responses and/or converting new regulatory cells (termed infectious tolerance). These methods are not restricted to cells with known phenotypic markers and can be extended to any cell population. Furthermore, donor directed allospecificity of regulatory cells (an important goal in the field) can be assessed by using third party donor cells or graft either in vitro or in vivo. Finally, to determine the specific tolerogenic capacity of these regulatory cells, we provide protocols to assess the humoral anti-donor antibody responses and the capacity of the recipient to develop humoral responses against new or former known antigens. The models of tolerance described can be used to further characterize regulatory cells, to identify new biomarkers, and immunoregulatory molecules, and are adaptable to other transplantation models or autoimmune diseases in rodent or human.

In Vitro and In Vivo Assessment of T, B and Myeloid Cells Suppressive Activity and Humoral Responses from Transplant Recipients

Here, we present a protocol to induce tolerance in transplantation, and assess in vitro and in vivo the suppressive capacity of distinct cell subsets from the recipient and the immune status of the recipient toward donor or exogenous antigens.

생체 외에서 그리고 Vivo에서 T, B 및 골수성 세포 진압 활동 및 이식 받는 체액 응답의 평가

The main concern in transplantation is to achieve specific tolerance through induction of regulatory cells. The understanding of tolerance mechanisms ...

Analysis of Shear Flow-induced Migration of Murine Marginal Zone B Cells In Vitro

Marginal zone B cells (MZBs) are a population of B cells that reside in the mouse splenic marginal zones that envelop follicles. To reach the follicles, MZBs must migrate up the shear force of blood flow. We present here a method for analyzing this flow-induced MZB migration in vitro. First, MZBs are isolated from the mouse spleen. Second, MZBs are settled on integrin ligands in flow chamber slides, exposed to shear flow, and imaged under a microscope while migrating. Third, images of the migrating MZBs are processed using the MTrack2 automatic cell tracking plugin for ImageJ, and the resulting cell tracks are quantified using the Ibidi chemotaxis tool. The migration data reveal how fast the cells move, how often they change direction, whether the shear flow vector affects their migration direction, and which integrin ligands are involved. Although we use MZBs, the method can easily be adapted for analyzing migration of any leukocyte that responds to the force of shear flow.

Marginal zone B cells (MZBs) respond to the force of shear flow by re-orienting their migration path up the flow. This protocol shows how to record and analyze the migration using a fluidics unit, pump, microscope imaging system, and free software.

분석 Murine 가장자리 지역 B 세포 생체 외에서의 전단 흐름 유도 마이그레이션

Marginal zone B cells (MZBs) are a population of B cells that reside in the mouse splenic marginal zones that envelop follicles. To reach the follicles, ...

Studying Organelle Dynamics in B Cells During Immune Synapse Formation

Recognition of surface-tethered antigens&#160;by the B cell receptor (BCR)&#160;triggers the formation of an immune synapse (IS), where both signaling&#160;and antigen uptake are coordinated. IS formation involves dynamic actin remodeling accompanied by the polarized recruitment to the synaptic membrane of the centrosome and associated intracellular organelles such as lysosomes and the Golgi apparatus. Initial stages of actin remodeling allow B cells to increase their cell surface and maximize the quantity of antigen-BCR complexes gathered at the synapse. Under certain conditions, when B cells recognize antigens associated to rigid surfaces, this process is coupled to the local recruitment and secretion of lysosomes, which can facilitate antigen extraction. Uptaken antigens&#160;are internalized into specialized endo-lysosome compartments for processing into peptides, which are loaded onto major histocompatibility complex II (MHC-II) molecules for further presentation to T helper cells. Therefore, studying organelle dynamics associated with the formation of an IS is crucial to understanding how B cells are activated. In the present article we will discuss both imaging and a biochemical technique used to study changes in intracellular organelle positioning and cytoskeleton rearrangements that are associated with the formation of an IS in B cells.

Herein we describe two approaches to characterize cell polarization events in B lymphocytes during the formation of an IS. The first, involves quantification of organelle recruitment and cytoskeleton rearrangements at the synaptic membrane. The second is a biochemical approach, to characterize changes in composition of the centrosome, which undergoes polarization to the immune synapse.