Zika Virus Infection at Different Pregnancy Stages: Anatomopathological Findings, Target Cells and Viral Persistence in Placental Tissues

Lucia de Noronha; Camila Zanluca; Marion Burger; Andreia Akemi Suzukawa; Marina Azevedo; Patricia Z. Rebutini; Iolanda Maria Novadzki; Laurina Setsuko Tanabe; Mayra Marinho Presibella; Claudia Nunes Duarte dos Santos

The copyright holder for this preprint (which was not peer-reviewed) is the author/funder. . https://doi.org/10.1101/370528 doi: bioRxiv preprint cell culture model ( Figure S1 ). Additionally, 73 placental samples of other etiologies were tested by IHC using anti-ZIKV MAb, and no crossreactivity was observed. Also, RT-qPCR yielded negative results in most of these samples. Negative controls were obtained either by omitting the primary antibody from the incubation step or by using an unrelated MAb against Chikungunya virus (CHIKV), produced at ICC/Fiocruz-PR, as the primary antibody ( Figure S2 ). To better identify Hofbauer cells (HCs), the FFPE placental tissue specimens were incubated with the primary antibody anti-human CD163 (Invitrogen, Carlsbad, USA) by using the same protocol. The placenta slides (three slides from the placental disc, one slide from the chorioamniotic membrane and one slide from umbilical cord) were observed with an Olympus™ BX50 optical microscope (Tokyo, Japan), and photomicrographs were acquired in a high-power field (400×) using a Zeiss Axio Scan.Z1 TM scanner (Carl Zeiss,