African and Asian Zika virus isolates display phenotypic differences both in vitro and in vivo

Authors: SMITH, DARCI - Us Army Medical Research Institute Of Infectious Diseases; SPRAGUE, THOMAS - Us Army Medical Research Institute Of Infectious Diseases; HOLLIDAGE, BRADLEY - Us Army Medical Research Institute Of Infectious Diseases; VALDEZ, STEPHANIE - Us Army Medical Research Institute Of Infectious Diseases; PADILLA, SUSANA - Us Army Medical Research Institute Of Infectious Diseases; BELLANCA, STEPHANIE - Us Army Medical Research Institute Of Infectious Diseases; GOLDEN, JOSEPH - Us Army Medical Research Institute Of Infectious Diseases; COYNE, SUSAN - Us Army Medical Research Institute Of Infectious Diseases; KULESH, DAVID - Us Army Medical Research Institute Of Infectious Diseases; HADDOW, ANDREW - Us Army Medical Research Institute Of Infectious Diseases; KOEHLER, JEFF - Us Army Medical Research Institute Of Infectious Diseases; GROMOWSKI, GREGORY - Walter Reed Army Institute; JARMAN, RICHARD - Walter Reed Army Institute; ALERA, MARIA THERESA - Armed Forces Research Institute Of Medical Sciences; YOON, IN-KYU - Seoul National University; BUATHONG, ROME - Ministry Of Health; LOWEN, ROBERT - Us Army Medical Research Institute Of Infectious Diseases; KANE, CHRISTOPHER - Us Army Medical Research Institute Of Infectious Diseases; MINOGUE, TIMOTHY - Us Army Medical Research Institute Of Infectious Diseases; BAVARI, SINA - Us Army Medical Research Institute Of Infectious Diseases; TESH, ROBERT - University Of Texas Medical Branch; WEAVER, SCOTT - University Of Texas Medical Branch; Linthicum, Kenneth - Ken; PITT, MARGARET - Us Army Medical Research Institute Of Infectious Diseases; NASAR, FAROOQ - University Of Texas Medical Branch

Submitted to: American Journal of Tropical Medicine and Hygiene
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/15/2017
Publication Date: 2/1/2018
Citation: Smith, D.R., Sprague, T.R., Hollidage, B.S., Valdez, S.M., Padilla, S.L., Bellanca, S.A., Golden, J.W., Coyne, S.R., Kulesh, D.A., Haddow, A.D., Koehler, J.W., Gromowski, G.D., Jarman, R.G., Alera, M.P., Yoon, I., Buathong, R., Lowen, R.G., Kane, C.D., Minogue, T.D., Bavari, S., Tesh, R.B., Weaver, S.C., Linthicum, K., Pitt, M.L., Nasar, F. 2018. African and Asian Zika virus isolates display phenotypic differences both in vitro and in vivo. American Journal of Tropical Medicine and Hygiene. 98(2):432-444. doi:10.4269/ajtmh.17-0685.
DOI: https://doi.org/10.4269/ajtmh.17-0685

Interpretive Summary: Zika virus (ZIKV) is a mosquito-borne virus that was first isolated from monkeys in 1947 in the Zika Forest in Uganda. In the following year ZIKV was isolated from Aedes africanus mosquitoes, and subsequent studies demonstrated efficient transmission by Aedes aegypti. In the following decades (1950s-80s), ZIKV was isolated in sub-Saharan Africa and Southeast Asia, and suggesting maintenance in both sylvatic (primarily Aedes spp. mosquitoes and monkeys and urban cycles (mainly Aedes. aegypti and humans). ZIKV consists of a single serotype, with isolates comprising two geographic lineages (African and Asian) that have caused sporadic or under-reported human outbreaks. However, starting in 2007, outbreaks were reported in Yap Island in the Federated States of Micronesia, and in Gabon, and by 2013 ZIKV was imported from French Polynesia into northeast Brazil resulting in the largest reported epidemic to date and its subsequent expansion to many parts of Americas including mainland USA (Florida and Texas). Since 2007 ZIKV has spread to 84 countries and territories in the Americas, Asia, and Africa, with reported evidence of local transmission. In the present study, we investigated potential phenotypic differences between African (ArD 41525) and Asian isolates (CPC-0740, SV0127-14) in animals, mosquitoes and cell culture.

Technical Abstract: Zika virus (ZIKV) is a mosquito-borne flavivirus that has emerged since 2007 to cause outbreaks in Africa, Asia, Oceania, and most recently in the Americas. Here we utilized isolate history, as well as genetic and phylogenetic analyses to characterize three low-passage isolates representing African (ArD 41525) and Asian (CPC-0740, SV0127-14) lineages in order to investigate potential phenotypic differences in vitro and in vivo. The African isolate displayed a large plaque phenotype (~3-4 mm) on Vero and HEK-293 cells, whereas Asian isolates either exhibited small plaque phenotype (~1-2 mm) or did not produce any plaques. In multiple-step replication kinetics in nine different vertebrate and insect cell lines, the African isolate consistently displayed faster replication kinetics and yielded ~10 to 10,000-fold higher peak virus titers (infectious or RNA copies), than Asian isolates. Oral exposure of Aedes aegypti mosquitoes with the African isolate yielded higher infection and dissemination rates than Asian isolates. Infection of Ifnar1-/- mice with the African isolate produced uniformly fatal disease, whereas infection with Asian isolates produced either a delay in time-to-death or a significantly lower mortality rate. Lastly, the African isolate was >10,000-fold more virulent than Asian isolates in an IFN-I antibody blockade mouse model. These data demonstrate substantial phenotypic differences between low passage African and Asian isolates both in vitro and in vivo, and warrant further investigation. They also highlight the need for basic characterization of ZIKV isolates as the utilization of uncharacterized isolates could have consequences for animal model and therapeutic/vaccine development.