A Chimeric Zika Virus between Viral Strains MR766 and BeH819015 Highlights a Role for E-glycan Loop in Antibody-mediated Virus Neutralization

Zika virus (ZIKV) is an emerging mosquito-borne flavivirus which is of major public health concern. ZIKV infection is recognized as the cause of congenital Zika disease and other neurological defects, with no specific prophylactic or therapeutic treatments. As the humoral immune response is an essential component of protective immunity, there is an urgent need for effective vaccines that confer protection against ZIKV infection. In the present study, we evaluate the immunogenicity of chimeric viral clone ZIKBeHMR-2, in which the region encoding the structural proteins of the African strain MR766 backbone was replaced with its counterpart from the epidemic strain BeH819015. Three amino-acid substitutions I152T, T156I, and H158Y were introduced in the glycan loop of the E protein (E-GL) making ZIKBeHMR-2 a non-glycosylated virus. Adult BALB/c mice inoculated intraperitoneally with ZIKBeHMR-2 developed anti-ZIKV antibodies directed against viral proteins E and NS1 and a booster dose increased antibody titers. Immunization with ZIKBeHMR-2 resulted in a rapid production of neutralizing anti-ZIKV antibodies. Antibody-mediated ZIKV neutralization was effective against viral strain MR766, whereas epidemic ZIKV strains were poorly sensitive to neutralization by anti-ZIKBeHMR-2 immune sera. From our data, we propose that the three E-GL residues at positions E-152, E-156, and E-158 greatly influence the accessibility of neutralizing antibody epitopes on ZIKV.

Download Full-text

Distinct cellular immune signatures in acute Zika virus infection are associated with high or low persisting neutralizing antibody titers

10.1101/2021.05.27.446054 ◽

2021 ◽

Author(s):

Elizabeth E. McCarthy ◽

Pamela M. Odorizzi ◽

Emma Lutz ◽

Carolyn P. Smullin ◽

Iliana Tenvooren ◽

...

Keyword(s):

Zika Virus ◽

Neutralizing Antibodies ◽

Viral Infections ◽

Immune Cell ◽

Acute Infection ◽

Neutralizing Antibody ◽

Natural Immunity ◽

Zikv Infection ◽

Antibody Titers ◽

Cellular Immune

Although the formation of a durable neutralizing antibody response after an acute viral infection is a key component of protective immunity, little is known about why some individuals generate high versus low neutralizing antibody titers to infection or vaccination. Infection with Zika virus (ZIKV) during pregnancy can cause devastating fetal outcomes, and efforts to understand natural immunity to this infection are essential for optimizing vaccine design. In this study, we leveraged the high-dimensional single-cell profiling capacity of mass cytometry (CyTOF) to deeply characterize the cellular immune response to acute and convalescent ZIKV infection in a cohort of blood donors in Puerto Rico incidentally found to be viremic during the 2015-2016 epidemic in the Americas. During acute ZIKV infection, we identified widely coordinated responses across innate and adaptive immune cell lineages. High frequencies of multiple activated innate immune subsets, as well as activated follicular helper CD4+ T cells and proliferating CD27-IgD- B cells, during acute infection were associated with high titers of ZIKV neutralizing antibodies at 6 months post-infection. On the other hand, low titers of ZIKV neutralizing antibodies were associated with immune features that suggested a cytotoxic-skewed immune "set-point." Our study offers insight into the cellular coordination of immune responses and identifies candidate cellular biomarkers that may offer predictive value in vaccine efficacy trials for ZIKV and other acute viral infections aimed at inducing high titers of neutralizing antibodies.

Download Full-text

Zika virus is transmitted in neural progenitor cells via cell-to-cell spread and infection is inhibited by the autophagy inducer trehalose

Journal of Virology ◽

10.1128/jvi.02024-20 ◽

2020 ◽

pp. JVI.02024-20

Author(s):

Alex E Clark ◽

Zhe Zhu ◽

Florian Krach ◽

Jeremy N Rich ◽

Gene W. Yeo ◽

...

Keyword(s):

Viral Replication ◽

Progenitor Cells ◽

Zika Virus ◽

Neural Progenitor Cells ◽

Neutralizing Antibody ◽

Neural Progenitor ◽

Health Concern ◽

Free Virus ◽

Zikv Infection ◽

Infected Cells

Zika virus (ZIKV) is a mosquito-borne human pathogen that causes congenital Zika syndrome and neurological symptoms in some adults. There are currently no approved treatments or vaccines for ZIKV, and exploration of therapies targeting host processes could avoid viral development of drug resistance. The purpose of our study was to determine if the non-toxic and widely used disaccharide trehalose, which showed antiviral activity against Human Cytomegalovirus (HCMV) in our previous work, could restrict ZIKV infection in clinically relevant neural progenitor cells (NPCs). Trehalose is known to induce autophagy, the degradation and recycling of cellular components. Whether autophagy is proviral or antiviral for ZIKV is controversial and depends on cell type and specific conditions used to activate or inhibit autophagy. We show here that trehalose treatment of NPCs infected with recent ZIKV isolates from Panama and Puerto Rico significantly reduces viral replication and spread. In addition, we demonstrate that ZIKV infection in NPCs spreads primarily cell-to-cell as an expanding infectious center, and NPCs are infected via contact with infected cells far more efficiently than by cell-free virus. Importantly, ZIKV was able to spread in NPCs in the presence of neutralizing antibody.Importance Zika virus causes birth defects and can lead to neurological disease in adults. While infection rates are currently low, ZIKV remains a public health concern with no treatment or vaccine available. Targeting a cellular pathway to inhibit viral replication is a potential treatment strategy that avoids development of antiviral resistance. We demonstrate in this study that the non-toxic autophagy-inducing disaccharide trehalose reduces spread and output of ZIKV in infected neural progenitor cells (NPCs), the major cells infected in the fetus. We show that ZIKV spreads cell-to-cell in NPCs as an infectious center and that NPCs are more permissive to infection by contact with infected cells than by cell-free virus. We find that neutralizing antibody does not prevent the spread of the infection in NPCs. These results are significant in demonstrating anti-ZIKV activity of trehalose and in clarifying the primary means of Zika virus spread in clinically relevant target cells.

Download Full-text

Maternal vaccination and protective immunity against Zika virus vertical transmission

Nature Communications ◽

10.1038/s41467-019-13589-1 ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 9

Author(s):

Chao Shan ◽

Xuping Xie ◽

Huanle Luo ◽

Antonio E. Muruato ◽

Yang Liu ◽

...

Keyword(s):

Zika Virus ◽

Protective Immunity ◽

Neutralizing Antibody ◽

In Utero ◽

Pregnant Mouse ◽

T Cell Response ◽

Zikv Infection ◽

Maternal Immunization ◽

Maternal Vaccination ◽

Pregnant Mice

AbstractAn important goal of the Zika virus (ZIKV) vaccine is to prevent a congenital syndrome in fetuses of pregnant women, but studies directly evaluating maternal vaccination for ZIKV are lacking. Here we report maternal vaccination using a live-attenuated ZIKV vaccine (3ʹUTR-∆10-LAV) in a pregnant mouse model. Maternal immunization with 3ʹUTR-∆10-LAV does not cause any adverse effects on pregnancy, fetal development, or offspring behavior. One maternal immunization fully protects dams against ZIKV infection and in utero transmission. Although neutralizing antibody alone is sufficient to prevent in utero transmission, a higher neutralizing titer is required to protect pregnant mice against in utero transmission than that required to protect non-pregnant mice against viral infection. The immunized dams transfer maternal antibodies to pups, which protect neonates against ZIKV infection. Notably, pregnancy weakens maternal T cell response to 3ʹUTR-∆10-LAV vaccination. Our results suggest that, besides vaccinating non-pregnant individuals, 3ʹUTR-∆10-LAV may also be considered for maternal vaccination.

Download Full-text

Development of a potent Zika virus vaccine using self-amplifying messenger RNA

Science Advances ◽

10.1126/sciadv.aba5068 ◽

2020 ◽

Vol 6 (32) ◽

pp. eaba5068 ◽

Cited By ~ 1

Author(s):

Kate Luisi ◽

Kaitlyn M. Morabito ◽

Katherine E. Burgomaster ◽

Mayuri Sharma ◽

Wing-Pui Kong ◽

...

Keyword(s):

Zika Virus ◽

Messenger Rna ◽

Protective Immunity ◽

Nonhuman Primates ◽

Neutralizing Antibody ◽

Effective Vaccine ◽

Proof Of Concept ◽

Zikv Infection ◽

Vaccine Candidates ◽

Rapid Responses

Zika virus (ZIKV) is the cause of a pandemic associated with microcephaly in newborns and Guillain-Barre syndrome in adults. Currently, there are no available treatments or vaccines for ZIKV, and the development of a safe and effective vaccine is a high priority for many global health organizations. We describe the development of ZIKV vaccine candidates using the self-amplifying messenger RNA (SAM) platform technology delivered by cationic nanoemulsion (CNE) that allows bedside mixing and is particularly useful for rapid responses to pandemic outbreaks. Two immunizations of either of the two lead SAM (CNE) vaccine candidates elicited potent neutralizing antibody responses to ZIKV in mice and nonhuman primates. Both SAM (CNE) vaccines protected these animals from ZIKV challenge, with one candidate providing complete protection against ZIKV infection in nonhuman primates. The data provide a preclinical proof of concept that a SAM (CNE) vaccine candidate can rapidly elicit protective immunity against ZIKV.

Download Full-text

DNA vaccination before conception protects Zika virus–exposed pregnant macaques against prolonged viremia and improves fetal outcomes

Science Translational Medicine ◽

10.1126/scitranslmed.aay2736 ◽

2019 ◽

Vol 11 (523) ◽

pp. eaay2736 ◽

Cited By ~ 11

Author(s):

Koen K. A. Van Rompay ◽

Rebekah I. Keesler ◽

Amir Ardeshir ◽

Jennifer Watanabe ◽

Jodie Usachenko ◽

...

Keyword(s):

Zika Virus ◽

Fetal Loss ◽

Fetal Brain ◽

Neutralizing Antibody ◽

Fetal Outcomes ◽

Zikv Infection ◽

Macaque Model ◽

Fetal Infection ◽

Congenital Zika Syndrome ◽

Antibody Titers

Zika virus (ZIKV) infection of pregnant women is associated with congenital Zika syndrome (CZS) and no vaccine is available, although several are being tested in clinical trials. We tested the efficacy of ZIKV DNA vaccine VRC5283 in a rhesus macaque model of congenital ZIKV infection. Most animal vaccine experiments have a set pathogen exposure several weeks or months after vaccination. In the real world, people encounter pathogens years or decades after vaccination, or may be repeatedly exposed if the virus is endemic. To more accurately mimic how this vaccine would be used, we immunized macaques before conception and then exposed them repeatedly to ZIKV during early and mid-gestation. In comparison to unimmunized animals, vaccinated animals had a significant reduction in peak magnitude and duration of maternal viremia, early fetal loss, fetal infection, and placental and fetal brain pathology. Vaccine-induced neutralizing antibody titers on the day of first ZIKV exposure were negatively associated with the magnitude of maternal viremia, and the absence of prolonged viremia was associated with better fetal outcomes. These data support further clinical development of ZIKV vaccine strategies to protect against negative fetal outcomes.

Download Full-text

Titers of Neutralizing Antibodies against SARS-CoV-2 Are Independent of Symptoms of Non-Severe COVID-19 in Young Adults

Viruses ◽

10.3390/v13020284 ◽

2021 ◽

Vol 13 (2) ◽

pp. 284

Author(s):

Hulda R. Jonsdottir ◽

Michel Bielecki ◽

Denise Siegrist ◽

Thomas W. Buehrer ◽

Roland Züst ◽

...

Keyword(s):

Young Adults ◽

Neutralizing Antibodies ◽

Severe Disease ◽

Humoral Response ◽

Neutralizing Antibody ◽

Neutralization Assay ◽

Asymptomatic Infection ◽

Homogeneous Population ◽

Humoral Immune ◽

Antibody Titers

Neutralizing antibodies are an important part of the humoral immune response to SARS-CoV-2. It is currently unclear to what extent such antibodies are produced after non-severe disease or asymptomatic infection. We studied a cluster of SARS-CoV-2 infections among a homogeneous population of 332 predominantly male Swiss soldiers and determined the neutralizing antibody response with a serum neutralization assay using a recombinant SARS-CoV-2-GFP. All patients with non-severe COVID-19 showed a swift humoral response within two weeks after the onset of symptoms, which remained stable for the duration of the study. One month after the outbreak, titers in COVID-19 convalescents did not differ from the titers of asymptomatically infected individuals. Furthermore, symptoms of COVID-19 did not correlate with neutralizing antibody titers. Therefore, we conclude that asymptomatic infection can induce the same humoral immunity as non-severe COVID-19 in young adults.

Download Full-text

Immunogenicity and structures of a rationally designed prefusion MERS-CoV spike antigen

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1707304114 ◽

2017 ◽

Vol 114 (35) ◽

pp. E7348-E7357 ◽

Cited By ~ 282

Author(s):

Jesper Pallesen ◽

Nianshuang Wang ◽

Kizzmekia S. Corbett ◽

Daniel Wrapp ◽

Robert N. Kirchdoerfer ◽

...

Keyword(s):

Receptor Binding ◽

Case Fatality ◽

Neutralizing Antibody ◽

Human Populations ◽

Receptor Binding Domain ◽

Potential Mechanism ◽

Primary Target ◽

Humoral Immune ◽

Receptor Recognition ◽

Antibody Titers

Middle East respiratory syndrome coronavirus (MERS-CoV) is a lineage C betacoronavirus that since its emergence in 2012 has caused outbreaks in human populations with case-fatality rates of ∼36%. As in other coronaviruses, the spike (S) glycoprotein of MERS-CoV mediates receptor recognition and membrane fusion and is the primary target of the humoral immune response during infection. Here we use structure-based design to develop a generalizable strategy for retaining coronavirus S proteins in the antigenically optimal prefusion conformation and demonstrate that our engineered immunogen is able to elicit high neutralizing antibody titers against MERS-CoV. We also determined high-resolution structures of the trimeric MERS-CoV S ectodomain in complex with G4, a stem-directed neutralizing antibody. The structures reveal that G4 recognizes a glycosylated loop that is variable among coronaviruses and they define four conformational states of the trimer wherein each receptor-binding domain is either tightly packed at the membrane-distal apex or rotated into a receptor-accessible conformation. Our studies suggest a potential mechanism for fusion initiation through sequential receptor-binding events and provide a foundation for the structure-based design of coronavirus vaccines.

Download Full-text

Autophagy in Zika Virus Infection: A Possible Therapeutic Target to Counteract Viral Replication

International Journal of Molecular Sciences ◽

10.3390/ijms20051048 ◽

2019 ◽

Vol 20 (5) ◽

pp. 1048 ◽

Cited By ~ 11

Author(s):

Rossella Gratton ◽

Almerinda Agrelli ◽

Paola Tricarico ◽

Lucas Brandão ◽

Sergio Crovella

Keyword(s):

Public Health ◽

Viral Replication ◽

Zika Virus ◽

Health Concern ◽

Mtor Signaling Pathway ◽

Catabolic Pathway ◽

Public Health Concern ◽

Zikv Infection ◽

Fundamental Process

Zika virus (ZIKV) still constitutes a public health concern, however, no vaccines or therapies are currently approved for treatment. A fundamental process involved in ZIKV infection is autophagy, a cellular catabolic pathway delivering cytoplasmic cargo to the lysosome for degradation—considered as a primordial form of innate immunity against invading microorganisms. ZIKV is thought to inhibit the Akt-mTOR signaling pathway, which causes aberrant activation of autophagy promoting viral replication and propagation. It is therefore appealing to study the role of autophagic molecular effectors during viral infection to identify potential targets for anti-ZIKV therapeutic intervention.

Download Full-text

Effect of a booster-dose of rabies vaccine on the duration of virus neutralizing antibody titers in bovines

Revista da Sociedade Brasileira de Medicina Tropical ◽

10.1590/s0037-86821998000400006 ◽

1998 ◽

Vol 31 (4) ◽

pp. 367-371 ◽

Cited By ~ 5

Author(s):

Avelino Albas ◽

Paulo Eduardo Pardo ◽

Albério Antonio Barros Gomes ◽

Fernanda Bernardi ◽

Fumio Honma Ito

Keyword(s):

Immune Response ◽

Neutralizing Antibodies ◽

Booster Dose ◽

Neutralization Test ◽

Neutralizing Antibody ◽

Rabies Vaccine ◽

Western Region ◽

Humoral Immune ◽

Paulo State ◽

Antibody Titers

Humoral immune response using inactivated rabies vaccine was studied in 35 nelore cross-bred bovines of western region of São Paulo state. Ninety days after vaccination, 13 (92.8%) animals presented titers 30.5IU/ml, through mouse neutralization test. After 180 days, 9 (64.3%) sera showed titers 30.5IU/ml, after 270 days, only one (7.1%) showed a titer of 0.51IU/ml, and after 360 days, all animals showed titers < 0.5IU/ml. Group of animals receiving booster dose 30 days after vaccination presented, two months after, all with titers > 0.5IU/ml. At 180 days, 17 (80.9%) sera presented titers > 0.5IU/ml; at 270 days, 15 (71.4%), with titers 30.5IU/ml and at 360 days, 4 (19.0%), with titers 30.5IU/ml. Booster-dose ensured high levels of neutralizing antibodies for at least three months, and 240 days after revaccination, 71.4% of animals were found with titers 30.5IU/ml.

Download Full-text

Zika Virus: New Clinical Syndromes and Its Emergence in the Western Hemisphere

Journal of Virology ◽

10.1128/jvi.00252-16 ◽

2016 ◽

Vol 90 (10) ◽

pp. 4864-4875 ◽

Cited By ~ 279

Author(s):

Helen M. Lazear ◽

Michael S. Diamond

Keyword(s):

Zika Virus ◽

Antiviral Agents ◽

Western Hemisphere ◽

Health Concern ◽

Global Public Health ◽

Public Health Concern ◽

Zikv Infection ◽

Clinical Complications ◽

Clinical Syndromes ◽

Potential Interactions

Zika virus (ZIKV) had remained a relatively obscure flavivirus until a recent series of outbreaks accompanied by unexpectedly severe clinical complications brought this virus into the spotlight as causing an infection of global public health concern. In this review, we discuss the history and epidemiology of ZIKV infection, recent outbreaks in Oceania and the emergence of ZIKV in the Western Hemisphere, newly ascribed complications of ZIKV infection, including Guillain-Barré syndrome and microcephaly, potential interactions between ZIKV and dengue virus, and the prospects for the development of antiviral agents and vaccines.

Download Full-text