scholarly journals Cellular and Humoral Immunity Protect against Vaginal Zika Virus Infection in Mice

2018 ◽  
Vol 92 (7) ◽  
Author(s):  
Jason M. Scott ◽  
Tania J. Lebratti ◽  
Justin M. Richner ◽  
Xiaoping Jiang ◽  
Estefania Fernandez ◽  
...  

ABSTRACTZika virus (ZIKV), which can cause devastating disease in fetuses of infected pregnant women, can be transmitted by mosquito inoculation and sexual routes. Little is known about immune protection against sexually transmitted ZIKV. In this study, we show that previous infection through intravaginal or subcutaneous routes with a contemporary Brazilian strain of ZIKV can protect against subsequent intravaginal challenge with a homologous strain. Both routes of inoculation induced high titers of ZIKV-specific and neutralizing antibody in serum and the vaginal lumen. Virus-specific T cells were recruited to and retained in the female reproductive tract after intravaginal and subcutaneous ZIKV infection. Studies in mice with genetic or acquired deficiencies in B and/or T cells demonstrated that both lymphocyte populations redundantly protect against intravaginal challenge in ZIKV-immune animals. Passive transfer of ZIKV-immune IgG or T cells significantly limited intravaginal infection of naive mice, although antibody more effectively prevented dissemination throughout the reproductive tract. Collectively, our experiments begin to establish the immune correlates of protection against intravaginal ZIKV infection, which should inform vaccination strategies in nonpregnant and pregnant women.IMPORTANCEThe recent ZIKV epidemic resulted in devastating outcomes in fetuses and may affect reproductive health. Unlike other flaviviruses, ZIKV can be spread by sexual contact as well as a mosquito vector. While previous studies have identified correlates of protection for mosquito-mediated infection, few have focused on immunity against sexual transmission. As exposure to ZIKV via mosquito bite has likely occurred to many living in areas where ZIKV is endemic, our study addresses whether this route of infection can protect against subsequent sexual exposure. We demonstrate that subcutaneous ZIKV infection can protect against subsequent vaginal infection by generating both local antiviral T cell and antibody responses. Our research begins to define the immune correlates of protection for ZIKV infection in the vagina and provides a foundation for testing ZIKV vaccines against sexual transmission.

Viruses ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2244
Author(s):  
Elizabeth Balint ◽  
Amelia Montemarano ◽  
Emily Feng ◽  
Ali A. Ashkar

Following the recent outbreak of Zika virus (ZIKV) infections in Latin America, ZIKV has emerged as a global health threat due to its ability to induce neurological disease in both adults and the developing fetus. ZIKV is largely mosquito-borne and is now endemic in many parts of Africa, Asia, and South America. However, several reports have demonstrated persistent ZIKV infection of the male reproductive tract and evidence of male-to-female sexual transmission of ZIKV. Sexual transmission may broaden the reach of ZIKV infections beyond its current geographical limits, presenting a significant threat worldwide. Several mouse models of ZIKV infection have been developed to investigate ZIKV pathogenesis and develop effective vaccines and therapeutics. However, the majority of these models focus on mosquito-borne infection, while few have considered the impact of sexual transmission on immunity and pathogenesis. This review will examine the advantages and disadvantages of current models of mosquito-borne and sexually transmitted ZIKV and provide recommendations for the effective use of ZIKV mouse models.


2017 ◽  
Vol 91 (8) ◽  
Author(s):  
Thomas E. Morrison ◽  
Michael S. Diamond

ABSTRACT Zika virus (ZIKV) is an emerging mosquito-transmitted flavivirus that now causes epidemics affecting millions of people on multiple continents. The virus has received global attention because of some of its unusual epidemiological and clinical features, including persistent infection in the male reproductive tract and sexual transmission, an ability to cross the placenta during pregnancy and infect the developing fetus to cause congenital malformations, and its association with Guillain-Barré syndrome in adults. This past year has witnessed an intensive effort by the global scientific community to understand the biology of ZIKV and to develop pathogenesis models for the rapid testing of possible countermeasures. Here, we review the recent advances in and utility and limitations of newly developed mouse and nonhuman primate models of ZIKV infection and pathogenesis.


Pathogens ◽  
2018 ◽  
Vol 7 (2) ◽  
pp. 51 ◽  
Author(s):  
Lucia Da Silva

Sexual transmission of Zika virus (ZIKV) is a matter of great concern. Infectious viral particles can be shed in semen for as long as six months after infection and can be transferred to male and female sexual partners during unprotected sexual intercourse. The virus can be found inside spermatozoa and could be directly transferred to the oocyte during fertilization. Sexual transmission of ZIKV can contribute to the rise in number of infected individuals in endemic areas as well as in countries where the mosquito vector does not thrive. There is also the possibility, as has been demonstrated in mouse models, that the vaginal deposition of ZIKV particles present in semen could lead to congenital syndrome. In this paper, we review the current literature to understand ZIKV trafficking from the bloodstream to the human male reproductive tract and viral interactions with host cells in interstitial spaces, tubule walls, annexed glands and semen. We hope to highlight gaps to be filled by future research and potential routes for vaccine and antiviral development.


Viruses ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 291
Author(s):  
Erika R. Schwarz ◽  
Lilian J. Oliveira ◽  
Francesco Bonfante ◽  
Ruiyu Pu ◽  
Malgorzata A. Pozor ◽  
...  

Zika virus (ZIKV) is an arbovirus that causes birth defects, persistent male infection, and sexual transmission in humans. The purpose of this study was to continue the development of an ovine ZIKV infection model; thus, two experiments were undertaken. In the first experiment, we built on previous pregnant sheep experiments by developing a mid-gestation model of ZIKV infection. Four pregnant sheep were challenged with ZIKV at 57–64 days gestation; two animals served as controls. After 13–15 days (corresponding with 70–79 days of gestation), one control and two infected animals were euthanized; the remaining animals were euthanized at 20–22 days post-infection (corresponding with 77–86 days of gestation). In the second experiment, six sexually mature, intact, male sheep were challenged with ZIKV and two animals served as controls. Infected animals were serially euthanized on days 2–6 and day 9 post-infection with the goal of isolating ZIKV from the male reproductive tract. In the mid-gestation study, virus was detected in maternal placenta and spleen, and in fetal organs, including the brains, spleens/liver, and umbilicus of infected fetuses. Fetuses from infected animals had visibly misshapen heads and morphometrics revealed significantly smaller head sizes in infected fetuses when compared to controls. Placental pathology was evident in infected dams. In the male experiment, ZIKV was detected in the spleen, liver, testes/epididymides, and accessory sex glands of infected animals. Results from both experiments indicate that mid-gestation ewes can be infected with ZIKV with subsequent disruption of fetal development and that intact male sheep are susceptible to ZIKV infection and viral dissemination and replication occurs in highly vascular tissues (including those of the male reproductive tract).


2020 ◽  
Author(s):  
Megan B. Vogt ◽  
Francesca Frere ◽  
Seth A. Hawks ◽  
Claudia E. Perez ◽  
Sheryl Coutermarsh-Ott ◽  
...  

ABSTRACTZika virus (ZIKV) can infect developing fetuses in utero and cause severe congenital defects. This in utero transmission can occurs following ZIKV infection during pregnancy via sexual transmission or mosquito bite. Infected men may shed ZIKV RNA in semen for over six months post symptom onset, indicating that ZIKV may persistently infect the male reproductive tract (MRT). However, the site of persistent infection in the MRT and whether ZIKV can recrudesce in the MRT is unknown. We hypothesized that if ZIKV establishes a persistent infection in the MRT, then immunosuppressant treatment should stimulate ZIKV replication. We tested this hypothesis in a wild-type mouse model of ZIKV sexual transmission. Male mice were infected with ZIKV and immunosuppressed when they no longer shed infectious virus in their ejaculates. After immunosuppression, ejaculates and MRT tissues were monitored for infectious virus and ZIKV RNA. Our results show that ZIKV recrudescence did not occur following immunosuppression, as we did not detect significant levels of infectious virus in ejaculates or MRT tissues following immunosuppression. We did detect ZIKV RNA in the epididymides of mice treated with the immunosuppressant cyclophosphamide. Further analysis revealed that this ZIKV RNA was contained within the lumen of the epididymis. Our findings suggest that ZIKV persistently infects the epididymis within the male reproductive tract. This study provides insight into the mechanisms behind ZIKV sexual transmission, which may inform public health decisions regarding ZIKV risks.ImportanceZika virus (ZIKV) is an emerging mosquito-transmitted virus that typically causes mild and self-limiting febrile illness in humans; however, during the recent epidemic of ZIKV in the Americas, severe birth defects, such as microcephaly and club foot, were reported in infants born to ZIKV infected mothers. Additionally, sexual transmission has been identified as a secondary method of ZIKV transmission. Since ZIKV can be isolated from semen of infected men long after initial infection, it is imperative to understand the mechanism(s) of ZIKV infection of the male reproductive tract to prevent sexual transmission and ZIKV-associated birth defects. The significance of our research is in identifying a site of persistent ZIKV infection in the male reproductive tract and in assessing the likelihood that a persistently infected individual will begin shedding infectious virus in semen again. This information will enhance our understanding of ZIKV sexual transmission and inform health decisions regarding ZIKV risks.


2021 ◽  
Author(s):  
Blake Schouest ◽  
Alba Grifoni ◽  
John Pham ◽  
Jose Mateus ◽  
John Sydney ◽  
...  

The mosquito-borne Zika virus (ZIKV) spread rapidly into regions where dengue virus (DENV) is endemic, and flavivirus cross-reactive T cell responses have been observed repeatedly in animal models and in humans. Pre-existing cellular immunity to DENV is thought to contribute to protection in subsequent ZIKV infection, but the epitope targets of cross-reactive T cell responses have not been comprehensively identified. Using human blood samples from the DENV-endemic regions of Nicaragua and Sri Lanka that were collected before the global spread of ZIKV in 2016, we employed an in vitro expansion strategy to map ZIKV T cell epitopes in ZIKV-unexposed, DENV-seropositive donors. We identified 93 epitopes across the ZIKV proteome, and we observed patterns of immunodominance that were dependent on antigen size and sequence identity to DENV. We confirmed the immunogenicity of these epitopes through a computational HLA binding analysis, and we showed that cross-reactive T cells specifically recognize ZIKV peptides homologous to DENV sequences. We also found that these CD4 responses were derived from the memory T cell compartment. These data have implications for understanding the dynamics of flavivirus-specific T cell immunity in endemic areas. Importance Multiple flaviviruses, including Zika (ZIKV) and the four serotypes of dengue (DENV) viruses, are prevalent in the same large tropical and equatorial areas inhabited by hundreds of millions of people. The interplay of DENV and ZIKV infection is especially relevant, as these two viruses are endemic in largely overlapping regions, have significant sequence similarity, and share the same arthropod vector. Here, we define the targets of pre-existing immunity to ZIKV in unexposed subjects collected in dengue-endemic areas. We demonstrate that pre-existing immunity to DENV could shape ZIKV-specific responses, and DENV-ZIKV cross-reactive T cells can be expanded by stimulation with ZIKV peptides. The issue of potential ZIKV and DENV cross-reactivity is of relevance for understanding patterns of natural immunity, as well as for the development of diagnostic tests and vaccines.


Viruses ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 867 ◽  
Author(s):  
Sasha R. Azar ◽  
Scott C. Weaver

The unprecedented outbreak of Zika virus (ZIKV) infection in the Americas from 2015 to 2017 prompted the publication of a large body of vector competence data in a relatively short period of time. Although differences in vector competence as a result of disparities in mosquito populations and viral strains are to be expected, the limited competence of many populations of the urban mosquito vector, Aedes aegypti, from the Americas (when its susceptibility is viewed relative to other circulating/reemerging mosquito-borne viruses such as dengue (DENV), yellow fever (YFV), and chikungunya viruses (CHIKV)) has proven a paradox for the field. This has been further complicated by the lack of standardization in the methodologies utilized in laboratory vector competence experiments, precluding meta-analyses of this large data set. As the calls for the standardization of such studies continue to grow in number, it is critical to examine the elements of vector competence experimental design. Herein, we review the various techniques and considerations intrinsic to vector competence studies, with respect to contemporary findings for ZIKV, as well as historical findings for other arboviruses, and discuss potential avenues of standardization going forward.


2019 ◽  
Vol 93 (11) ◽  
Author(s):  
Angelica Cifuentes Kottkamp ◽  
Elfie De Jesus ◽  
Rebecca Grande ◽  
Julia A. Brown ◽  
Adam R. Jacobs ◽  
...  

ABSTRACT Arthropod-borne viruses represent a significant public health threat worldwide, yet there are few antiviral therapies or prophylaxes targeting these pathogens. In particular, the development of novel antivirals for high-risk populations such as pregnant women is essential to prevent devastating disease such as that which was experienced with the recent outbreak of Zika virus (ZIKV) in the Americas. One potential avenue to identify new and pregnancy-acceptable antiviral compounds is to repurpose well-known and widely used FDA-approved drugs. In this study, we addressed the antiviral role of atovaquone, an FDA Pregnancy Category C drug and pyrimidine biosynthesis inhibitor used for the prevention and treatment of parasitic infections. We found that atovaquone was able to inhibit ZIKV and chikungunya virus virion production in human cells and that this antiviral effect occurred early during infection at the initial steps of viral RNA replication. Moreover, we were able to complement viral replication and virion production with the addition of exogenous pyrimidine nucleosides, indicating that atovaquone functions through the inhibition of the pyrimidine biosynthesis pathway to inhibit viral replication. Finally, using an ex vivo human placental tissue model, we found that atovaquone could limit ZIKV infection in a dose-dependent manner, providing evidence that atovaquone may function as an antiviral in humans. Taken together, these studies suggest that atovaquone could be a broad-spectrum antiviral drug and a potential attractive candidate for the prophylaxis or treatment of arbovirus infection in vulnerable populations, such as pregnant women and children. IMPORTANCE The ability to protect vulnerable populations such as pregnant women and children from Zika virus and other arbovirus infections is essential to preventing the devastating complications induced by these viruses. One class of antiviral therapies may lie in known pregnancy-acceptable drugs that have the potential to mitigate arbovirus infections and disease, yet this has not been explored in detail. In this study, we show that the common antiparasitic drug atovaquone inhibits arbovirus replication through intracellular nucleotide depletion and can impair ZIKV infection in an ex vivo human placental explant model. Our study provides a novel function for atovaquone and highlights that the rediscovery of pregnancy-acceptable drugs with potential antiviral effects can be the key to better addressing the immediate need for treating viral infections and preventing potential birth complications and future disease.


2018 ◽  
Vol 6 (1) ◽  
Author(s):  
Hana M El Sahly ◽  
Rodion Gorchakov ◽  
Lilin Lai ◽  
Muktha S Natrajan ◽  
Shital M Patel ◽  
...  

Abstract Background Clinical, virologic, and immunologic characteristics of Zika virus (ZIKV) infections in US patients are poorly defined. Methods US subjects with suspected ZIKV infection were enrolled. Clinical data and specimens were prospectively collected for ZIKV RNA detection and serologic and cellular assays. Confirmed ZIKV infection (cases) and ZIKV-negative (controls) subjects were compared. Dengue-experienced and dengue-naïve cases were also compared. Results We enrolled 45 cases and 14 controls. Commonly reported symptoms among cases and controls were maculopapular rash (97.8% and 81.8%), fatigue (86.7% and 81.8%), and arthralgia (82.2% and 54.5%), respectively. The sensitivity (94%) and duration of infection detection (80% positivity at 65–79 days after disease onset) by polymerase chain reaction were highest in whole-blood specimens. ZIKV-neutralizing antibodies had a half-life of 105 days and were significantly higher in dengue virus–experienced cases than naïve ones (P = .046). In intracellular cytokine staining assays, the ZIKV proteins targeted most often by peripheral blood mononuclear cells from cases were structural proteins C and E for CD4+ T cells and nonstructural proteins NS3, NS5, and NS4B for CD8+ T cells. Conclusions ZIKV RNA detection was more frequent and prolonged in whole-blood specimens. Immunoglobulin G (IgG) and neutralizing antibodies, but not IgM, were influenced by prior dengue infection. Robust cellular responses to E and nonstructural proteins have potential vaccine development implications.


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