Magnani Diogo M, Silveira Cassia G T, Ricciardi Michael J, Gonzalez-Nieto Lucas, Pedreño-Lopez Núria, Bailey Varian K, Gutman Martin J, Maxwell Helen S, Domingues Aline, Costa Priscilla R, Ferrari Lilian, Goulart Raphaella, Martins Mauricio A, Martinez-Navio José M, Fuchs Sebastian P, Kalil Jorge, Timenetsky Maria do Carmo, Wrammert Jens, Whitehead Stephen S, Burton Dennis R, Desrosiers Ronald C, Kallas Esper G, Watkins David I
Department of Pathology, University of Miami Miller School of Medicine, Miami, Florida, USA.
Division of Clinical Immunology and Allergy, School of Medicine, University of São Paulo, São Paulo, Brazil.
J Virol. 2017 Oct 27;91(22). doi: 10.1128/JVI.00867-17. Print 2017 Nov 15.
Exposure to dengue virus (DENV) is thought to elicit lifelong immunity, mediated by DENV-neutralizing antibodies (nAbs). However, Abs generated by primary infections confer serotype-specific protection, and immunity against other serotypes develops only after subsequent infections. Accordingly, the induction of these nAb responses acquired after serial DENV infections has been a long-sought-after goal for vaccination. Nonetheless, it is still unclear if tetravalent vaccines can elicit or recall nAbs. In this study, we have characterized the responses from a volunteer who had been previously exposed to DENV and was immunized with the live attenuated tetravalent vaccine Butantan-DV, developed by the NIH and Butantan Institute. Eleven days after vaccination, we observed an ∼70-fold expansion of the plasmablast population. We generated 21 monoclonal Abs (MAbs) from singly sorted plasmablasts. These MAbs were the result of clonal expansions and had significant levels of somatic hypermutation (SHM). Nineteen MAbs (90.5%) neutralized at least one DENV serotype at concentrations of 1 μg/ml or less; 6 of the 21 MAbs neutralized three or more serotypes. Despite the tetravalent composition of the vaccine, we observed a neutralization bias in the induced repertoire: DENV3 was targeted by 18 of the 19 neutralizing MAbs (nMAbs). Furthermore, the P3D05 nMAb neutralized DENV3 with extraordinary potency (concentration to achieve half-maximal neutralization [Neut] = 0.03 μg/ml). Thus, the Butantan-DV vaccine engendered a mature, antigen-selected B cell repertoire. Our results suggest that preexisting responses elicited by a previous DENV3 infection were recalled by immunization. The dengue epidemic presents a global public health challenge that causes widespread economic burden and remains largely unchecked by existing control strategies. Successful control of the dengue epidemic will require effective prophylactic and therapeutic interventions. Several vaccine clinical efficacy trials are approaching completion, and the chances that one or more live attenuated tetravalent vaccines (LATVs) will be introduced worldwide is higher than ever. While it is widely accepted that dengue virus (DENV)-neutralizing antibody (nAb) titers are associated with protection, the Ab repertoire induced by LATVs remain uncharacterized. Here, we describe the isolation of potent (Neut < 0.1 μg/ml) nAbs from a DENV-seropositive volunteer immunized with the tetravalent vaccine Butantan-DV, which is currently in phase III trials.
接触登革病毒（DENV）被认为可引发由DENV中和抗体（nAbs）介导的终身免疫。然而，初次感染产生的抗体提供血清型特异性保护，而针对其他血清型的免疫仅在后续感染后才会产生。因此，诱导连续DENV感染后获得的这些nAb反应一直是疫苗接种长期追求的目标。尽管如此，四价疫苗是否能引发或唤起nAbs仍不清楚。在本研究中，我们对一名曾接触过DENV并接种了由美国国立卫生研究院（NIH）和布坦坦研究所开发的减毒活四价疫苗Butantan-DV的志愿者的反应进行了特征分析。接种疫苗11天后，我们观察到浆母细胞群体扩增了约70倍。我们从单个分选的浆母细胞中产生了21种单克隆抗体（MAbs）。这些MAbs是克隆扩增的结果，具有显著水平的体细胞超突变（SHM）。19种MAbs（90.5%）在浓度为1μg/ml或更低时中和至少一种DENV血清型；21种MAbs中有6种中和三种或更多血清型。尽管疫苗为四价组成，但我们在诱导的库中观察到中和偏向：19种中和MAbs（nMAbs）中有18种靶向DENV3。此外，P3D05 nMAb以非凡的效力中和DENV3（达到半数最大中和[Neut]的浓度 = 0.03μg/ml）。因此，Butantan-DV疫苗产生了一个成熟的、抗原选择的B细胞库。我们的结果表明，先前DENV3感染引发的既往反应通过免疫被唤起。登革热流行带来了全球公共卫生挑战，造成广泛的经济负担，并且在很大程度上仍未得到现有控制策略的遏制。成功控制登革热流行将需要有效的预防和治疗干预措施。几项疫苗临床疗效试验即将完成，一种或多种减毒活四价疫苗（LATVs）在全球范围内推出的可能性比以往任何时候都高。虽然人们普遍认为登革病毒（DENV）中和抗体（nAb）滴度与保护相关，但LATVs诱导的抗体库仍未得到表征。在此，我们描述了从一名接种了目前处于III期试验的四价疫苗Butantan-DV的DENV血清阳性志愿者中分离出强效（Neut < 0.1μg/ml）nAbs的情况。
