Justewicz D M, Morin M J, Robinson H L, Webster R G
Department of Virology and Molecular Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38101, USA.
J Virol. 1995 Dec;69(12):7712-7. doi: 10.1128/JVI.69.12.7712-7717.1995.
Immunization of mice with DNA encoding the influenza virus hemagglutinin (HA) affords complete protection against lethal influenza virus infection and the means to investigate the mechanisms of B-cell responsiveness to virus challenge. Using a single-cell enzyme-linked immunospot assay, we sought to determine the localization of HA-specific antibody-forming cells (AFCs) during the development of humoral immunity in mice given HA DNA vaccine by gene gun. At 33 days postvaccination, populations of AFCs were maintained in the spleen and bone marrow. In response to lethal challenge with influenza virus, the AFCs became localized at the site of antigenic challenge, i.e., within the draining lymph nodes of the lung compartment. Immunoglobulin G (IgG)- and IgA-producing AFCs were detected in lymph nodes of the upper and lower respiratory tracts, underscoring their importance in clearing virus from the lungs. Response to challenge required competent CD4+ T cells, without which no AFCs were generated, even those producing IgM. By contrast, in mice vaccinated with an HA-containing subunit vaccine, fewer AFCs were generated in response to challenge, and these animals were less capable of resisting infection. Our findings demonstrate the comparable localization of AFCs in response to challenge in mice vaccinated with either HA DNA or live virus. Moreover, the former strategy generates both IgG- and IgA-producing plasma cells.
用编码流感病毒血凝素（HA）的DNA免疫小鼠，可提供针对致命性流感病毒感染的完全保护，也是研究B细胞对病毒攻击反应机制的手段。我们使用单细胞酶联免疫斑点试验，试图确定通过基因枪接种HA DNA疫苗的小鼠在体液免疫发育过程中HA特异性抗体形成细胞（AFC）的定位。接种疫苗后33天，AFC群体在脾脏和骨髓中得以维持。在受到流感病毒的致命攻击后，AFC定位于抗原攻击部位，即肺区引流淋巴结内。在上、下呼吸道淋巴结中检测到产生免疫球蛋白G（IgG）和IgA的AFC，这突出了它们在清除肺部病毒方面的重要性。对攻击的反应需要有功能的CD4+T细胞，没有这些细胞，就不会产生AFC，甚至那些产生IgM的细胞也不会产生。相比之下，在用含HA的亚单位疫苗接种的小鼠中，对攻击产生的AFC较少，并且这些动物抵抗感染的能力较弱。我们的研究结果表明，接种HA DNA或活病毒的小鼠在受到攻击时，AFC的定位具有可比性。此外，前一种策略可产生产生IgG和IgA的浆细胞。
