我们感谢 Dr. 绣花卢, Dr., 和 Ms. 从疾病预防控制中心的流感部门的阿什利。我们感谢 CDC 流感部门的 Dr. 利伯, 帮助他准备图 3的图形。最后, 我们感谢 Dr. m Matrosovich, 马尔堡, 德国提供 MDCK-SIAT1 细胞。

<ol>
	<li>Reber, A., Katz, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immunological+assessment+of+influenza+vaccines+and+immune+correlates+of+protection.">Immunological assessment of influenza vaccines and immune correlates of protection.</a> Expert Rev of Vaccines. 12, 519-536 (2013).</li><li>Li, C. K., Rappuoli, R., Xu, X. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Correlates+of+protection+against+influenza+infection+in+humans--on+the+path+to+a+universal+vaccine?.">Correlates of protection against influenza infection in humans--on the path to a universal vaccine?.</a> Curr Opin in Immunol. 25, 470-476 (2013).</li><li>WHO Global Influenza Surveillance Network. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Manual for the labratory diagnosis and virological surveillence of influenza. , (2011).</li><li>Govorkova, E. A., Kodihalli, S., Alymova, I. V., Fanget, B., Webster, R. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Growth+and+immunogenicity+of+influenza+viruses+cultivated+in+Vero+or+MDCK+cells+and+in+embryonated+chicken+eggs.">Growth and immunogenicity of influenza viruses cultivated in Vero or MDCK cells and in embryonated chicken eggs.</a> Dev Biological Stand. 98, 39-51 (1999).</li><li>Levine, M. Z., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neutralizing+Antibody+Responses+to+Antigenically+Drifted+Influenza+A(H3N2)+Viruses+among+Children+and+Adolescents+following+2014-2015+Inactivated+and+Live+Attenuated+Influenza+Vaccination.">Neutralizing Antibody Responses to Antigenically Drifted Influenza A(H3N2) Viruses among Children and Adolescents following 2014-2015 Inactivated and Live Attenuated Influenza Vaccination.</a> Clin Vaccine Immunol : CVI. 23, 831-839 (2016).</li><li>Lin, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+characteristics+and+antigenic+properties+of+recently+emerged+subclade+3C.3a+and+3C.2a+human+influenza+A(H3N2)+viruses+passaged+in+MDCK+cells.">The characteristics and antigenic properties of recently emerged subclade 3C.3a and 3C.2a human influenza A(H3N2) viruses passaged in MDCK cells.</a> Influenza Other Respir Viruses. , (2017).</li><li>Lin, Y. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuraminidase+receptor+binding+variants+of+human+influenza+A(H3N2)+viruses+resulting+from+substitution+of+aspartic+acid+151+in+the+catalytic+site:+a+role+in+virus+attachment?.">Neuraminidase receptor binding variants of human influenza A(H3N2) viruses resulting from substitution of aspartic acid 151 in the catalytic site: a role in virus attachment?.</a> J of Virol. 84, 6769-6781 (2010).</li><li>Skowronski, D. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mutations+acquired+during+cell+culture+isolation+may+affect+antigenic+characterisation+of+influenza+A(H3N2)+clade+3C.2a+viruses.">Mutations acquired during cell culture isolation may affect antigenic characterisation of influenza A(H3N2) clade 3C.2a viruses.</a> Euro Surveillance. 21, 30112 (2016).</li><li>Matrosovich, M., Matrosovich, T., Carr, J., Roberts, N. A., Klenk, H. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Overexpression+of+the+alpha-2,6-sialyltransferase+in+MDCK+cells+increases+influenza+virus+sensitivity+to+neuraminidase+inhibitors.">Overexpression of the alpha-2,6-sialyltransferase in MDCK cells increases influenza virus sensitivity to neuraminidase inhibitors.</a> J of Virol. 77, 8418-8425 (2003).</li><li>Oh, D. Y., Barr, I. G., Mosse, J. A., Laurie, K. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MDCK-SIAT1+cells+show+improved+isolation+rates+for+recent+human+influenza+viruses+compared+to+conventional+MDCK+cells.">MDCK-SIAT1 cells show improved isolation rates for recent human influenza viruses compared to conventional MDCK cells.</a> J Clin Microbiol. 46, 2189-2194 (2008).</li><li>US Department of Health and Human Services. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Biosafety in Microbiological and Biomedical Laboratories. , (2009).</li><li>Reed, H. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+simple+method+of+estimating+fifty+percent+endpoints.">A simple method of estimating fifty percent endpoints.</a> The American Journal of Hygiene. 27, (1938).</li><li>Laurie, K. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=International+Laboratory+Comparison+of+Influenza+Microneutralization+Assays+for+A(H1N1)pdm09,+A(H3N2),+and+A(H5N1)+Influenza+Viruses+by+CONSISE.">International Laboratory Comparison of Influenza Microneutralization Assays for A(H1N1)pdm09, A(H3N2), and A(H5N1) Influenza Viruses by CONSISE.</a> Clinical Vaccine Immunol : CVI. 22, 957-964 (2015).</li><li>Lin, Y., Gu, Y., McCauley, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimization+of+a+Quantitative+Micro-neutralization+Assay.">Optimization of a Quantitative Micro-neutralization Assay.</a> J Vis Exp : JoVE. , (2016).</li><li>van Baalen, C. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=ViroSpot+microneutralization+assay+for+antigenic+characterization+of+human+influenza+viruses.">ViroSpot microneutralization assay for antigenic characterization of human influenza viruses.</a> Vaccine. 35, 46-52 (2017).</li></ol>

作者报告没有利益冲突。这份出版物的调查结果和结论是作者的, 不一定代表疾病控制和预防中心和资助机构的观点。

锰测定法是流感血清学中用于检测流感感染或疫苗接种后抗体应答的主要方法之一。由锰测定产生的滴常被用作许多流感血清研究的主要结果。锰测定法也广泛用于血清诊断和疫苗免疫原性评价。国际 inter-lab 的研究已经进行比较, 在多个实验室的锰化验结果14。
与 HI 相比, 锰测定法的目的是直接测量细胞培养中能中和病毒感染的功能性抗体。世界各地的野?...

流感病毒每年继续造成人类人口的发病率和死亡率。HA 是流感病毒的主要表面糖蛋白。中和抗体靶向 HA 是主要的免疫机制, 与流感感染的保护相关的1,2。血凝抑制 (HI) 和锰测定法是广泛用于检测流感病毒感染或疫苗接种后的人血清中抗体应答的两种方法3。高含量的检测方法可抑制红细胞的病毒血凝, 并被认为是一种替代性试验。与 HI 不同, 锰测定法可以直接测定人血清中的抗体水平, 从而消除细胞培养中的流感感染。MDCK 细胞常用于流感病毒分离和锰含量测定4。
流感病毒经常进行抗原漂移和转移, 获取 HA 蛋白的突变, 从而改变病毒的受体结合特异性。自2014年以来, 新的一组 (H3N2) 病毒出现并继续流传到本赛季。这些病毒大多数属于基因组 3 c. 2 a 和 3 c. 3 a 基于 HA 蛋白质的系统进化分析。许多循环 3 c. 2 的病毒已经降低了 hemagglutinate 红细胞的能力, 因此不能用 hi 化验5来表征。中和测定必须用于测量这些病毒的抗体应答, 而不 hemagglutinate6。此外, 研究表明, 这些当代 a (H3N2) 病毒改变受体结合性能与早期 a (H3N2) 病毒, 并倾向于积累文化适应突变和多态性时, 传代在体外细胞区域性7,8,9。与传统的 MDCK 细胞相比, MDCK-SIAT1 是由 Matrosovich et al.开发的细胞系。通过α2,6-sialtransferase (SIAT1) 的 cDNA MDCK 细胞的稳定转染。这条细胞线表达了增加的α2,6-唾液半乳糖基和减少α2,3-唾液酸基的数量比父 MDCK 细胞10。与 MDCK 细胞11相比, MDCK-SIAT1 细胞已显示出改善 (H3N2) 病毒的隔离率。最近, 林et al.报告说, 对于新出现的 3 c. 2 a 和 3 c. 3 a 人 a (H3N2) 流感病毒, 更忠实的病毒复制和更好的病毒传染, 当病毒被培养了在 MDCK-SIAT1 细胞线与 MDCK 细胞对比7。因此, MDCK-SIAT1 细胞更适合于锰测定, 以表征抗体对最近一组 (H3N2) 病毒的反应。
在这里, 我们描述了一个使用 MDCK-SIAT1 细胞的锰测定方法来测量当代 3 c. 2 a 和 3 c. 3 a a (H3N2) 病毒在人类血清中的抗体应答。在这种方法中, 可以使用在卵或细胞中生长的病毒。含有中和抗体的热灭活血清先被连续稀释, 然后用 100 TCID50/甲型流感病毒 (H3N2) 进行孵育, 使血清中的抗体与病毒结合。然后将 MDCK-SIAT1 细胞添加到病毒抗体混合物中, 在37° c 下孵育 18-20 h, 5% CO2 , 允许 A (H3N2) 病毒感染 MDCK-SIAT1 细胞并进行复制。经过一夜的孵化, 该板块是固定和数量的病毒在每个井是量化的 ELISA 使用流感的一个 NP 单克隆抗体。NP 的检测表明病毒感染的存在和中和抗体的缺乏。中和抗体滴度被定义为最高的血清稀释的倒数, 提供了≥50% 抑制病毒传染性。

<table border="0" cellpadding="0" cellspacing="0" width="969">
	<tbody>
		<tr height="42">
			<td height="42" style="height:42px;width:295px;">Dulbecco&#8217;s Modified Eagle Medium (DMEM) with high Glucose</td>
			<td style="width:181px;">Life Science</td>
			<td style="width:185px;">11965</td>
			<td style="width:308px;">A critical component of Sterile Cell Culture, Virus Propagation and Virus Diluent Media</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Fetal bovine serum (FBS)</td>
			<td style="width:181px;">Hyclone</td>
			<td style="width:185px;">SH30070.03</td>
			<td style="width:308px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:295px;">Bovine Serum Albumin (BSA) Fraction V, Protase Free</td>
			<td style="width:181px;">Sigma-Aldrich</td>
			<td style="width:185px;">3117332001</td>
			<td style="width:308px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">L-Glutamine</td>
			<td style="width:181px;">Life Science</td>
			<td style="width:185px;">25030-081</td>
			<td style="width:308px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Sodium pyruvate</td>
			<td style="width:181px;">Life Science</td>
			<td>11360-070</td>
			<td style="width:308px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Geneticin G-418 disulfate salt&#160;</td>
			<td style="width:181px;">Sigma-Aldrich</td>
			<td style="width:185px;">A1720-5G&#160;&#160;</td>
			<td style="width:308px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">HEPES</td>
			<td style="width:181px;">Life Science</td>
			<td style="width:185px;">15630-080</td>
			<td style="width:308px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Penicillin/Streptomycin</td>
			<td style="width:181px;">Life Science</td>
			<td style="width:185px;">15140-122</td>
			<td style="width:308px;"></td>
		</tr>
		<tr height="28">
			<td height="28" style="height:28px;width:295px;">Acetone</td>
			<td style="width:181px;">VWR</td>
			<td style="width:185px;">67-64-1</td>
			<td style="width:308px;">Used at an 80% concentration</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:295px;">Phosphate-Citrate Buffer with Sodium Perborate&#160;</td>
			<td style="width:181px;">Sigma-Aldrich</td>
			<td style="width:185px;">SLBF2806V</td>
			<td style="width:308px;"></td>
		</tr>
		<tr height="32">
			<td height="32" style="height:32px;width:295px;">O-Phenylenediamine Dihydrochloride tablet</td>
			<td style="width:181px;">Sigma-Aldrich</td>
			<td style="width:185px;">SLBQ1086V</td>
			<td style="width:308px;">1 tablet per 100ml of cell culture grade water</td>
		</tr>
		<tr height="30">
			<td height="30" style="height:30px;width:295px;">Sulfuric Acid</td>
			<td style="width:181px;">Fisher Scientific</td>
			<td style="width:185px;">A510-P500</td>
			<td style="width:308px;">Used 0.5M final concentration</td>
		</tr>
		<tr height="32">
			<td height="32" style="height:32px;width:295px;">Ethanol, Denatured, 4L</td>
			<td style="width:181px;">VWR</td>
			<td style="width:185px;">EM-AX0422-3</td>
			<td style="width:308px;">Used at an 70% concentration</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Trypsin-EDTA</td>
			<td style="width:181px;">Life Science</td>
			<td style="width:185px;">1748048</td>
			<td style="width:308px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">RDE II &#34;Seiken&#34;</td>
			<td style="width:181px;">Denka Seiken</td>
			<td style="width:185px;">370013</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Tween 20</td>
			<td style="width:181px;">Sigma-Aldrich</td>
			<td style="width:185px;">P1379-500ml</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Anti-NP mouse monoclonal Ab</td>
			<td style="width:181px;">Millipore pool</td>
			<td style="width:185px;">MAB 8257 MAB 8258</td>
			<td style="width:308px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Anti-mouse IgG HRP&#160;</td>
			<td style="width:181px;">KPL</td>
			<td style="width:185px;">074-1802</td>
			<td style="width:308px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">96-well flat-bottom plates</td>
			<td style="width:181px;">Thermo Scientific</td>
			<td style="width:185px;">3455</td>
			<td style="width:308px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Plate reader</td>
			<td style="width:181px;">Molecular Device</td>
			<td style="width:185px;">Spectromax 384 plus</td>
			<td style="width:308px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Cell Culture Flask 162 cm2/Vent Cap</td>
			<td style="width:181px;">Corning/VWR</td>
			<td style="width:185px;">3151</td>
			<td></td>
		</tr>
	</tbody>
</table>

measuring influenza neutralizing antibody responses to a(h3n2) viruses in human sera by microneutralization assays using mdck-siat1 cells

对流感病毒血 (HA) 的中和抗体被认为是与保护流感感染相关的主要免疫机制。Microneutralization (MN) 检测通常用于测量流感疫苗接种或感染后人血清中和抗体的反应。机达比犬肾脏 (MDCK) 细胞是常用的细胞基质的锰测定方法。然而, 目前循环 3 c. 2 a 和 3 c. 3 a a (H3N2) 流感病毒已获得改变受体结合特异性。MDCK-SIAT1 细胞系增加α-26 唾液半乳糖基在表面上已证明提供改善感染和更忠实的复制比传统的 MDCK 细胞为这些当代 A (H3N2) 病毒。在这里, 我们描述了使用 MDCK-SIAT1 细胞的锰测定方法, 它已经被优化, 以量化中和抗体滴到这些当代 a (H3N2) 病毒。在本协议中, 含有中和抗体的热灭活血清首先依次稀释, 然后用 100 TCID50/流感病毒 A (H3N2) 细菌孵育, 使血清中的抗体与病毒结合。然后将 MDCK-SIAT1 细胞添加到病毒抗体混合物中, 在37° c 下孵育 18-20 h, 5% CO2 , 允许 (H3N2) 病毒感染 MDCK-SIAT1 细胞。在夜间孵化后, 用流感 A 核 (NP) 单克隆抗体的酶联免疫吸附试验 (ELISA) 对每一个井中的病毒数量进行固定和定量。中和抗体滴度被定义为最高的血清稀释的相互作用, 提供50% 抑制病毒传染性。

测定病毒种群的传染性是锰测定的第一步。图 2说明了用于确定病毒储存的 TCID50的版面布局。对于未知传染性的病毒种群, 病毒可以从多个 pre-dilutions 滴定, 例如 10-2和 10-3, 以便捕获最佳的滴定曲线来计算病毒的传染性。在锰测定中使用的病毒数量应标准化到 100 TCID50/井 (50 µL)。病毒储存的最小稀释量达到 100 TCID50...

Watch this Scientific Journal Video about Measuring Influenza Neutralizing Antibody Responses to AH3N2 Viruses in Human Sera by Microneutralization Assays Using MDCK-SIAT1 Cells at JoVE.com

Measuring Influenza Neutralizing Antibody Responses to AH3N2 Viruses in Human Sera by Microneutralization Assays Using MDCK-SIAT1 Cells

流感中和抗体与流感感染的保护相关。Microneutralization 测定检测人血清中和抗体, 通常用于流感人血清学。我们描述了一个 microneutralization 的方法, 使用 MDCK-SIAT1 细胞测量中和抗体滴的当代 3 c. 2 a 和 3 c. 3 a a (H3N2) 病毒在流感疫苗接种或感染后。

用 MDCK-SIAT1 细胞 Microneutralization 法测定人血清中中和 (H3N2) 病毒的流感中和抗体反应

Neutralizing antibodies against hemagglutinin (HA) of influenza viruses are considered the main immune mechanism that correlates with protection for ...

measuring-influenza-neutralizing-antibody-responses-to-h3n2-viruses

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JoVE Journal

Immunology and Infection

Measuring Influenza Neutralizing Antibody Responses to A(H3N2) Viruses in Human Sera by Microneutralization Assays Using MDCK-SIAT1 Cells

17.9K 次观看.  Centers for Disease Control and Prevention. 流感中和抗体与流感感染的保护相关。Microneutralization 测定检测人血清中和抗体, 通常用于流感人血清学。我们描述了一个 microneutralization 的方法, 使用 MDCK-SIAT1 细胞测量中和抗体滴的当代 3 c. 2 a 和 3 c. 3 a a (H3N2) 病毒在流感疫苗接种或感染后。

视频: Measuring Influenza Neutralizing Antibody Responses to AH3N2 Viruses in Human Sera by Microneutralization Assays Using MDCK-SIAT1 Cells

Establishing a Liquid-covered Culture of Polarized Human Airway Epithelial Calu-3 Cells to Study Host Cell Response to Respiratory Pathogens In vitro

The apical and basolateral surfaces of airway epithelial cells demonstrate directional responses to pathogen exposure in vivo. Thus, ideal in vitro models for examining cellular responses to respiratory pathogens polarize, forming apical and basolateral surfaces. One such model is differentiated normal human bronchial epithelial cells (NHBE). However, this system requires lung tissue samples, expertise isolating and culturing epithelial cells from tissue, and time to generate an air-liquid interface culture.
Calu-3 cells, derived from a human bronchial adenocarcinoma, are an alternative model for examining the response of proximal airway epithelial cells to respiratory insult1, pharmacological compounds2-6, and bacterial7-9 and viral pathogens, including influenza virus, rhinovirus and severe acute respiratory syndrome - associated coronavirus10-14. Recently, we demonstrated that Calu-3 cells are susceptible to respiratory syncytial virus (RSV) infection in a manner consistent with NHBE15,16 . Here, we detail the establishment of a polarized, liquid-covered culture (LCC) of Calu-3 cells, focusing on the technical details of growing and culturing Calu-3 cells, maintaining cells that have been cultured into LCC, and we present the method for performing respiratory virus infection of polarized Calu-3 cells.
To consistently obtain polarized Calu-3 LCC, Calu-3 cells must be carefully subcultured before culturing in Transwell inserts. Calu-3 monolayer cultures should remain below 90% confluence, should be subcultured fewer than 10 times from frozen stock, and should regularly be supplied with fresh medium. Once cultured in Transwells, Calu-3 LCC must be handled with care. Irregular media changes and mechanical or physical disruption of the cell layers or plates negatively impact polarization for several hours or days. Polarization is monitored by evaluating trans-epithelial electrical resistance (TEER) and is verified by evaluating the passive equilibration of sodium fluorescein between the apical and basolateral compartments17,18 . Once TEER plateaus at or above 1,000 &Omega;&times;cm2, Calu-3 LCC are ready to use to examine cellular responses to respiratory pathogens.

Establishing a Liquid-covered Culture of Polarized Human Airway Epithelial Calu-3 Cells to Study Host Cell Response to Respiratory Pathogens In vitro

The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention.

建立的液体覆盖的文化偏光人类呼吸道上皮的CALU-3细胞研究呼吸系统病原宿主细胞的反应<em在体外</em

The  apical and basolateral surfaces of airway epithelial cells demonstrate  directional responses to pathogen exposure in  vivo. Thus, ideal in vitro ...

科研

免疫与感染

Intranasal Administration of Recombinant Influenza Vaccines in Chimeric Mouse Models to Study Mucosal Immunity

Vaccines are one of the greatest achievements of mankind, and have saved millions of lives over the last century. Paradoxically, little is known about the physiological mechanisms that mediate immune responses to vaccines perhaps due to the overall success of vaccination, which has reduced interest into the molecular and physiological mechanisms of vaccine immunity. However, several important human pathogens including influenza virus still pose a challenge for vaccination, and may benefit from immune-based strategies. 
Although influenza reverse genetics has been successfully applied to the generation of live-attenuated influenza vaccines (LAIVs), the addition of molecular tools in vaccine preparations such as tracer components to follow up the kinetics of vaccination in vivo, has not been addressed. In addition, the recent generation of mouse models that allow specific depletion of leukocytes during kinetic studies has opened a window of opportunity to understand the basic immune mechanisms underlying vaccine-elicited protection. Here, we describe how the combination of reverse genetics and chimeric mouse models may help to provide new insights into how vaccines work at physiological and molecular levels, using as example a recombinant, cold-adapted, live-attenuated influenza vaccine (LAIV). We utilized laboratory-generated LAIVs harboring cell tracers as well as competitive bone marrow chimeras (BMCs) to determine the early kinetics of vaccine immunity and the main physiological mechanisms responsible for the initiation of vaccine-specific adaptive immunity. In addition, we show how this technique may facilitate gene function studies in single animals during immune responses to vaccines. We propose that this technique can be applied to improve current prophylactic strategies against pathogens for which urgent medical countermeasures are needed, for example influenza, HIV, Plasmodium, and hemorrhagic fever viruses such as Ebola virus.

There is an overall lack of knowledge about how vaccines work. Here we propose the combined use of reverse genetics and bone marrow chimeric mice to gain insight into the early host immune responses to vaccines with a special focus on dendritic cells and T cell immunity.

重组流感疫苗的嵌合体小鼠模型鼻腔给药研究黏膜免疫

Vaccines are one of the greatest achievements of mankind, and have saved millions of lives over the last century. Paradoxically, little is known about the ...

Measuring Attachment and Internalization of Influenza A Virus in A549 Cells by Flow Cytometry

Attachment to target cells followed by internalization are the very first steps of the life cycle of influenza A virus (IAV). We provide here a detailed protocol for measuring relative changes in the amount of viral particles that attach to A549 cells, a human lung epithelial cell line, as well as in the amount of particles that are internalized into the cell. We use biotinylated virus which can be easily detected following staining with Cy3-labeled streptavidin (STV-Cy3). We describe the growth, purification and biotinylation of A/WSN/33, a widely used IAV laboratory strain. Cold-bound biotinylated IAV particles on A549 cells are stained with STV-Cy3 and measured using flow cytometry. To investigate uptake of viral particles, cold-bound virus is allowed to internalize at 37 &#176;C. In order to differentiate between external and internalized viral particles, a blocking step is applied: Free binding spots on the biotin of attached virus on the cell surface are bound by unlabeled streptavidin (STV). Subsequent cell permeabilization and staining with STV-Cy3 then enables detection of internalized viral particles. We present a calculation to determine the relative amount of internalized virus. This assay is suitable to measure effects of drug-treatments or other manipulations on attachment or internalization of IAV.

We present a protocol describing a semi-quantitative method for measuring both, the attachment of influenza A virus to A549 cells, as well as the internalization of virus particles into the target cells by flow cytometry.

通过流式细胞仪测量附件和流感的内在病毒在A549细胞

Attachment to target cells followed by internalization are the very first steps of the life cycle of influenza A virus (IAV). We provide here a detailed ...

Measuring Physiological Responses of Drosophila Sensory Neurons to Lipid Pheromones Using Live Calcium Imaging

Unlike mammals, insects such as Drosophila have multiple taste organs. The chemosensory neurons on the legs, proboscis, wings and ovipositor of Drosophila express gustatory receptors1,2, ion channels3-6, and ionotropic receptors7 that are involved in the detection of volatile and non-volatile sensory cues. These neurons directly contact tastants such as food, noxious substances and pheromones and therefore influence many complex behaviors such as feeding, egg-laying and mating. Electrode recordings and calcium imaging have been widely used in insects to quantify the neuronal responses evoked by these tastants. However, electrophysiology requires specialized equipment and obtaining measurements from a single taste sensillum can be technically challenging depending on the cell-type, size, and position. In addition, single neuron resolution in Drosophila can be difficult to achieve since taste sensilla house more than one type of chemosensory neuron. The live calcium imaging method described here allows responses of single gustatory neurons in live flies to be measured. This method is especially suitable for imaging neuronal responses to lipid pheromones and other ligand types that have low solubility in water-based solvents.

Measuring Physiological Responses of Drosophila Sensory Neurons to Lipid Pheromones Using Live Calcium Imaging

The forelegs and proboscis of Drosophila contain a rich repertoire of gustatory sensory neurons. Here, we present a method using calcium imaging to measure physiological responses from sensory neurons in the foreleg and proboscis of live flies upon exogenous application of a gustatory pheromone.

测量的生理反应<em&gt;果蝇</em&gt;感觉神经元脂质费洛蒙使用实时钙成像

Unlike mammals, insects such as Drosophila have multiple taste organs. The chemosensory neurons on the legs, proboscis, wings and ovipositor of Drosophila ...

Measuring Influenza Neuraminidase Inhibition Antibody Titers by Enzyme-linked Lectin Assay

Antibodies to neuraminidase (NA), the second most abundant surface protein on influenza virus, contribute toward protection against influenza. Traditional methods to measure NA inhibiting (NI) antibody titers are not practical for routine serology. This protocol describes the enzyme-linked lectin assay (ELLA), a practical alternative method to measure NI titers that is performed in 96 well plates coated with a large glycoprotein substrate, fetuin. NA cleaves terminal sialic acids from fetuin, exposing the penultimate sugar, galactose. Peanut agglutinin (PNA) is a lectin with specificity for galactose and therefore the extent of desialylation can be quantified using a PNA-horseradish peroxidase conjugate, followed by addition of a chromogenic peroxidase substrate. The optical density that is measured is proportional to NA activity. To measure NI antibody titers, serial dilutions of sera are incubated at 37 &#176;C O/N on fetuin-coated plates with a fixed amount of NA. The reciprocal of the highest serum dilution that results in &#8805;50% inhibition of NA activity is designated as the NI antibody titer. The ELLA provides a practical format for routine evaluation of human antibody responses following influenza infection or vaccination.

We describe the enzyme-linked lectin assay (ELLA) for measuring influenza neuraminidase (NA)-inhibition antibody titers in sera. The assay uses peanut agglutinin to quantify galactose residues that become accessible when NA removes sialic acid from fetuin-coated, 96-well plates.

通过酶联凝集素测定来测量神经氨酸酶流感抑制抗体滴度

Antibodies to neuraminidase (NA), the second most abundant surface protein on influenza virus, contribute toward protection against influenza. Traditional ...

Using Zebrafish Models of Human Influenza A Virus Infections to Screen Antiviral Drugs and Characterize Host Immune Cell Responses

Each year, seasonal influenza outbreaks profoundly affect societies worldwide. In spite of global efforts, influenza remains an intractable healthcare burden. The principle strategy to curtail infections is yearly vaccination. In individuals who have contracted influenza, antiviral drugs can mitigate symptoms. There is a clear and unmet need to develop alternative strategies to combat influenza. Several animal models have been created to model host-influenza interactions. Here, protocols for generating zebrafish models for systemic and localized human influenza A virus (IAV) infection are described. Using a systemic IAV infection model, small molecules with potential antiviral activity can be screened. As a proof-of-principle, a protocol that demonstrates the efficacy of the antiviral drug Zanamivir in IAV-infected zebrafish is described. It shows how disease phenotypes can be quantified to score the relative efficacy of potential antivirals in IAV-infected zebrafish. In recent years, there has been increased appreciation for the critical role neutrophils play in the human host response to influenza infection. The zebrafish has proven to be an indispensable model for the study of neutrophil biology, with direct impacts on human medicine. A protocol to generate a localized IAV infection in the Tg(mpx:mCherry) zebrafish line to study neutrophil biology in the context of a localized viral infection is described. Neutrophil recruitment to localized infection sites provides an additional quantifiable phenotype for assessing experimental manipulations that may have therapeutic applications. Both zebrafish protocols described faithfully recapitulate aspects of human IAV infection. The zebrafish model possesses numerous inherent advantages, including high fecundity, optical clarity, amenability to drug screening, and availability of transgenic lines, including those in which immune cells such as neutrophils are labeled with fluorescent proteins. The protocols detailed here exploit these advantages and have the potential to reveal critical insights into host-IAV interactions that may ultimately translate into the clinic.

Systemic and localized zebrafish infection models for human influenza A virus are demonstrated. Using a systemic infection model, zebrafish can be used to screen antiviral drugs. Using a localized infection model, zebrafish can be used to characterize host immune cell responses.

使用人类流感病毒感染的斑马鱼模型到屏幕抗病毒药物和表征宿主免疫细胞反应

Each year, seasonal influenza outbreaks profoundly affect societies worldwide. In spite of global efforts, influenza remains an intractable healthcare ...

Fluorescence-based Neuraminidase Inhibition Assay to Assess the Susceptibility of Influenza Viruses to The Neuraminidase Inhibitor Class of Antivirals

The neuraminidase (NA) inhibitors are the only class of antivirals approved for the treatment and prophylaxis of influenza that are effective against currently circulating strains. In addition to their use in treating seasonal influenza, the NA inhibitors have been stockpiled by a number of countries for use in the event of a pandemic. It is therefore important to monitor the susceptibility of circulating influenza viruses to this class of antivirals. There are different types of assays that can be used to assess the susceptibility of influenza viruses to the NA inhibitors, but the enzyme inhibition assays using either a fluorescent substrate or a chemiluminescent substrate are the most widely used and recommended. This protocol describes the use of a fluorescence-based assay to assess influenza virus susceptibility to NA inhibitors. The assay is based on the NA enzyme cleaving the 2&#8242;-(4-Methylumbelliferyl)-&#945;-D-N-acetylneuraminic acid (MUNANA) substrate to release the fluorescent product 4-methylumbelliferone (4-MU). Therefore, the inhibitory effect of an NA inhibitor on the influenza virus NA is determined based on the concentration of the NA inhibitor that is required to reduce 50% of the NA activity, given as an IC50 value.

We describe the use of a phenotypic fluorescence-based neuraminidase inhibition assay to assess the susceptibility of influenza A and B viruses to the neuraminidase inhibitor class of antivirals.

荧光为基础的神经氨酸酶抑制测定流感病毒的易感性评估抗病毒药的神经氨酸酶抑制剂类

The neuraminidase (NA) inhibitors are the only class of antivirals approved for the treatment and prophylaxis of influenza that are effective against ...

Generation of Escape Variants of Neutralizing Influenza Virus Monoclonal Antibodies

Influenza viruses exhibit a remarkable ability to adapt and evade the host immune response. One way is through antigenic changes that occur on the surface glycoproteins of the virus. The generation of escape variants is a powerful method in elucidating how viruses escape immune detection and in identifying critical residues required for antibody binding. Here, we describe a protocol on how to generate influenza A virus escape variants by utilizing human or murine monoclonal antibodies (mAbs) directed against the viral hemagglutinin (HA). With the use of our technique, we previously characterized critical residues required for the binding of antibodies targeting either the head or stalk of the novel avian H7N9 HA. The protocol can be easily adapted for other virus systems. Analyses of escape variants are important for modeling antigenic drift, determining single nucleotide polymorphisms (SNPs) conferring resistance and virus fitness, and in the designing of vaccines and/or therapeutics.

We describe a method by which we identify critical residues required for the binding of human or murine monoclonal antibodies that target the viral hemagglutinin of influenza A viruses. The protocol can be adapted to other virus surface glycoproteins and their corresponding neutralizing antibodies.

中和流感病毒单克隆抗体逃逸变种的产生

Influenza viruses exhibit a remarkable ability to adapt and evade the host immune response. One way is through antigenic changes that occur on the surface ...

Isolation of Salmonella typhimurium-containing Phagosomes from Macrophages

Salmonella typhimurium is a facultative intracellular bacterium that causes gastroenteritis in humans. After invasion of the lamina propria, S. typhimurium bacteria are quickly detected and phagocytized by macrophages, and contained in vesicles known as phagosomes in order to be degraded. Isolation of S. typhimurium-containing phagosomes have been widely used to study how S. typhimurium infection alters the process of phagosome maturation to prevent bacterial degradation. Classically, the isolation of bacteria-containing phagosomes has been performed by sucrose gradient centrifugation. However, this process is time-consuming, and requires specialized equipment and a certain degree of dexterity. Described here is a simple and quick method for the isolation of S. typhimurium-containing phagosomes from macrophages by coating the bacteria with biotin-streptavidin-conjugated magnetic beads. Phagosomes obtained by this method can be suspended in any buffer of choice, allowing the utilization of isolated phagosomes for a broad range of assays, such as protein, metabolite, and lipid analysis. In summary, this method for the isolation of S. typhimurium-containing phagosomes is specific, efficient, rapid, requires minimum equipment, and is more versatile than the classical method of isolation by sucrose gradient-ultracentrifugation.

Isolation of Salmonella typhimurium-containing Phagosomes from Macrophages

We describe here a simple and quick method for the isolation of Salmonella typhimurium-containing phagosomes from macrophages by coating the bacteria with biotin and streptavidin.

巨噬细胞中含有吞噬的鼠伤寒沙门氏菌的分离

Salmonella typhimurium is a facultative intracellular bacterium that causes gastroenteritis in humans. After invasion of the lamina propria, S. ...

Identification of Mouse and Human Antibody Repertoires by Next-Generation Sequencing

The immense adaptability of antigen recognition by antibodies is the basis of the acquired immune system. Despite our understanding of the molecular mechanisms underlying the production of the vast repertoire of antibodies by the acquired immune systems, it has not yet been possible to arrive at a global view of a complete antibody repertoire. In particular, B cell repertoires have been regarded as a black box because of their astronomical number of antibody clones. However, next-generation sequencing technologies are enabling breakthroughs to increase our understanding of the B cell repertoire. In this report, we describe a simple and efficient method to visualize and analyze whole individual mouse and human antibody repertoires. From the immune organs, representatively from spleen in mice and peripheral blood mononuclear cells in humans, total RNA was prepared, reverse transcribed, and amplified using the 5&#39;-RACE method. Using a universal forward primer and antisense primers for the antibody class-specific constant domains, antibody mRNAs were uniformly amplified in proportions reflecting their frequencies in the antibody populations. The amplicons were sequenced by next-generation sequencing (NGS), yielding more than 105 antibody sequences per immunological sample. We describe the protocols for antibody sequence analyses including V(D)J-gene-segment annotation, a bird&#39;s-eye view of the antibody repertoire, and our computational methods.

Here, we describe protocols for the analysis and visualization of the structure and constitution of whole antibody repertoires. This involves the acquisition of vast sequences of antibody RNA using next-generation sequencing.

近一代测序鉴定小鼠与人体抗体的分泌

The immense adaptability of antigen recognition by antibodies is the basis of the acquired immune system. Despite our understanding of the molecular ...

用 MDCK-SIAT1 细胞 Microneutralization 法测定人血清中中和 (H3N2) 病毒的流感中和抗体反应

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建立的液体覆盖的文化偏光人类呼吸道上皮的CALU-3细胞研究呼吸系统病原宿主细胞的反应