Fayolle C, Osickova A, Osicka R, Henry T, Rojas M J, Saron M F, Sebo P, Leclerc C
Unité de Biologie des Régulations Immunitaires, Institut Pasteur, Paris, France.
J Virol. 2001 Aug;75(16):7330-8. doi: 10.1128/JVI.75.16.7330-7338.2001.
CyaA, the adenylate cyclase toxin from Bordetella pertussis, can deliver its N-terminal catalytic domain into the cytosol of a large number of eukaryotic cells and particularly into professional antigen-presenting cells. We have previously identified within the primary structure of CyaA several permissive sites at which insertion of peptides does not alter the ability of the toxin to enter cells. This property has been exploited to design recombinant CyaA toxoids capable of delivering major histocompatibility complex (MHC) class I-restricted CD8(+) T-cell epitopes into antigen-presenting cells and to induce specific CD8(+) cytotoxic T-lymphocyte (CTL) responses in vivo. Here we have explored the capacity of the CyaA vector carrying several different CD8(+) T-cell epitopes to prime multiple CTL responses. The model vaccine consisted of a polyepitope made of three CTL epitopes from lymphocytic choriomeningitis virus (LCMV), the V3 region of human immunodeficiency virus gp120, and chicken ovalbumin, inserted at three different sites of the catalytic domain of genetically detoxified CyaA. Each of these epitopes was processed on delivery by CyaA and presented in vitro to specific T-cell hybridomas. Immunization of mice by CyaA toxoids carrying the polyepitope lead to the induction of specific CTL responses for each of the three epitopes, as well as to protection against a lethal viral challenge. Moreover, mice primed against the vector by mock CyaA or a recombinant toxoid were still able to develop strong CTL responses after subsequent immunization with a recombinant CyaA carrying a foreign CD8(+) CTL epitope. These results highlight the potency of the adenylate cyclase vector for induction of protective CTL responses with multiple specificity and/or broad MHC restriction.
百日咳博德特氏菌的腺苷酸环化酶毒素（CyaA）可将其N端催化结构域递送至大量真核细胞的胞质溶胶中，尤其是递送至专职抗原呈递细胞中。我们之前在CyaA的一级结构中确定了几个允许插入肽段的位点，在此插入肽段不会改变毒素进入细胞的能力。这一特性已被用于设计重组CyaA类毒素，其能够将主要组织相容性复合体（MHC）I类限制性CD8(+) T细胞表位递送至抗原呈递细胞中，并在体内诱导特异性CD8(+) 细胞毒性T淋巴细胞（CTL）反应。在此，我们探究了携带几种不同CD8(+) T细胞表位的CyaA载体引发多种CTL反应的能力。该模型疫苗由一个多表位组成，该多表位包含来自淋巴细胞性脉络丛脑膜炎病毒（LCMV）的三个CTL表位、人类免疫缺陷病毒gp120的V3区以及鸡卵清蛋白，它们插入到经基因解毒的CyaA催化结构域的三个不同位点。这些表位中的每一个在被CyaA递送时都会被加工处理，并在体外呈递给特异性T细胞杂交瘤。用携带该多表位的CyaA类毒素免疫小鼠，可诱导针对这三个表位中每一个的特异性CTL反应，以及对致死性病毒攻击的保护作用。此外，用模拟CyaA或重组类毒素对载体进行初次免疫的小鼠，在用携带外源CD8(+) CTL表位的重组CyaA进行后续免疫后，仍能够产生强烈的CTL反应。这些结果突出了腺苷酸环化酶载体在诱导具有多种特异性和/或广泛MHC限制性的保护性CTL反应方面的效力。
