Virological, immunological and pathological findings of transplacentally transmitted bluetongue virus serotype 1 in IFNAR1-blocked mice during early and mid gestation

• Published in: Scientific reports 2020-02, Vol.10 (1), p.2164-2164, Article 2164
• Main Authors: Saminathan, M., Singh, K. P., Vineetha, S., Maity, Madhulina, Biswas, S. K., Manjunathareddy, G. B., Chauhan, H. C., Milton, A. A. P., Ramakrishnan, M. A., Maan, Sushila, Maan, N. S., Hemadri, D., Chandel, B. S., Gupta, V. K., Mertens, P. P. C.
• Format: Article
• Language: English
• Subjects: 13; 13/2; 13/31; 13/51; 14; 14/63; 38; 38/77; 631/326/596/2555; 692/699/255/2514; 96/106; Abortion; Animal diseases; Animals; Antigens; Antigens, Viral - immunology; Apoptosis; Bluetongue; Bluetongue - immunology; Bluetongue - pathology; Bluetongue - transmission; Bluetongue - virology; Bluetongue virus - immunology; Bluetongue virus - pathogenicity; Bone and Bones - abnormalities; Brain - abnormalities; CD4 antigen; CD8 antigen; Congenital defects; Congenital diseases; Decidua; Edema; Embryos; Encephalitis; Epidemiology; Female; Fetal Diseases - immunology; Fetal Diseases - pathology; Fetal Diseases - virology; Fetuses; Gestation; Humanities and Social Sciences; Immunohistochemistry; Immunology; Infections; Infectious Disease Transmission, Vertical; Laboratory animals; Lesions; Lymphocytes; Lymphocytes T; Mice; Monoclonal antibodies; multidisciplinary; Natural killer cells; Ovaries; Overwintering; Pathology; Peak load; Placenta; Pregnancy; Pregnancy Complications, Infectious - immunology; Pregnancy Complications, Infectious - pathology; Pregnancy Complications, Infectious - virology; Receptor, Interferon alpha-beta - deficiency; Receptor, Interferon alpha-beta - genetics; Science; Science (multidisciplinary); Sheep; Spleen; Spleen - immunology; T-Lymphocytes - immunology; Uterus; Vaccination; Vagina; Veterinary medicine; Viruses
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-020-58268-0

Transplacental transmission (TPT) of wild-type Indian BTV-1 had never been experimentally proved. This study was first time investigated TPT of Indian BTV-1 (isolated from aborted and stillborn goat fetal spleens). The sequential pathology, virological and immune cell kinetics (CD4 + , CD8 + T-lymphocytes and NK cells in spleen and PBMCs), and apoptosis in IFNAR1-blocked pregnant mice during early (infected on 1 GD) and mid (infected on 8 GD) gestation have been studied. There was higher rate of TPT during mid stage (71.43%) than early (57.14%) stage. In early stage reduced implantation sites, early embryonic deaths, abortions, and necro-haemorrhagic lesions had observed. Mid stage, congenital defects and neurological lesions in foetuses like haemorrhages, diffuse cerebral edema, necrotizing encephalitis and decreased bone size (Alizarin red staining) were noticed. BTV-1 antigen was first time demonstrable in cells of mesometrium, decidua of embryos, placenta, uterus, ovary, and brain of foetuses by immunohistochemistry and quantified by real-time qRT-PCR. BTV-inoculated mice were seroconverted by 7 and 5 dpi, and reached peak levels by 15 and 9 dpi in early and mid gestation, respectively. CD4 + and CD8 + cells were significantly decreased (increased ratio) on 7 dpi but subsequently increased on 15 dpi in early gestation. In mid gestation, increased CD8 + cells (decreased ratio) were observed. Apoptotic cells in PBMCs and tissues increased during peak viral load. This first time TPT of wild-type Indian BTV-1 deserves to be reported for implementation of control strategies. This model will be very suitable for further research into mechanisms of TPT, overwintering, and vaccination strategies.