scholarly journals Antibodies Elicited in Response to a Single Cycle Glycoprotein D Deletion Viral Vaccine Candidate Bind C1q and Activate Complement Mediated Neutralization and Cytolysis

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1284
Author(s):  
Maria Luisa Visciano ◽  
Aakash Mahant Mahant ◽  
Carl Pierce ◽  
Richard Hunte ◽  
Betsy C. Herold
Keyword(s):  
Neutralizing Antibodies ◽  
High Titer ◽  
Passive Immunization ◽  
Immune Serum ◽  
Effective Vaccine ◽  
Glycoprotein D ◽  
Single Cycle ◽  
Viral Vaccine ◽  
Trial Outcomes ◽  
Simplex Virus

Herpes simplex virus (HSV) prevention is a global health priority but, despite decades of research, there is no effective vaccine. Prior efforts focused on generating glycoprotein D (gD) neutralizing antibodies, but clinical trial outcomes were disappointing. The deletion of gD yields a single-cycle candidate vaccine (∆gD-2) that elicits high titer polyantigenic non-gD antibodies that exhibit little complement-independent neutralization but mediate antibody-dependent cellular cytotoxicity (ADCC) and phagocytosis (ADCP). Active or passive immunization with ΔgD-2 completely protects mice from lethal disease and latency following challenge with clinical isolates of either serotype. The current studies evaluated the role of complement in vaccine-elicited protection. The immune serum from the ΔgD-2 vaccinated mice exhibited significantly greater C1q binding compared to the serum from the gD protein vaccinated mice with infected cell lysates from either serotype as capture antigens. The C1q-binding antibodies recognized glycoprotein B. This resulted in significantly greater antibody-mediated complement-dependent cytolysis and neutralization. Notably, complete protection was preserved when the ΔgD-2 immune serum was passively transferred into C1q knockout mice, suggesting that ADCC and ADCP are sufficient in mice. We speculate that the polyfunctional responses elicited by ΔgD-2 may prove more effective in preventing HSV, compared to the more restrictive responses elicited by adjuvanted gD protein vaccines.

scholarly journals A Single-Cycle Glycoprotein D Deletion Viral Vaccine Candidate, ΔgD-2, Elicits Polyfunctional Antibodies That Protect against Ocular Herpes Simplex Virus

2020 ◽  
Vol 94 (13) ◽  
Author(s):  
Natalie L. M. Ramsey ◽  
Maria Visciano ◽  
Richard Hunte ◽  
Lip Nam Loh ◽  
Clare Burn Aschner ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Vaccine Candidate ◽  
Passive Immunization ◽  
Glycoprotein D ◽  
Single Cycle ◽  
Herpes Simplex Virus 1 ◽  
Passive Protection ◽  
Viral Vaccine ◽  
Simplex Virus

ABSTRACT Herpes simplex virus 1 (HSV-1) is a leading cause of infectious blindness, highlighting the need for effective vaccines. A single-cycle HSV-2 strain with the deletion of glycoprotein D, ΔgD-2, completely protected mice from HSV-1 and HSV-2 skin or vaginal disease and prevented latency following active or passive immunization in preclinical studies. The antibodies functioned primarily by activating Fc receptors to mediate antibody-dependent cellular cytotoxicity (ADCC). The ability of ADCC to protect the immune-privileged eye, however, may differ from skin or vaginal infections. Thus, the current studies were designed to compare active and passive immunization with ΔgD-2 versus an adjuvanted gD subunit vaccine (rgD-2) in a primary lethal ocular murine model. ΔgD-2 provided significantly greater protection than rgD-2 following a two-dose vaccine regimen, although both vaccines were protective compared to an uninfected cell lysate. However, only immune serum from ΔgD-2-vaccinated, but not rgD-2-vaccinated, mice provided significant protection against lethality in passive transfer studies. The significantly greater passive protection afforded by ΔgD-2 persisted after controlling for the total amount of HSV-specific IgG in the transferred serum. The antibodies elicited by rgD-2 had significantly higher neutralizing titers, whereas those elicited by ΔgD-2 had significantly more C1q binding and Fc gamma receptor activation, a surrogate for ADCC function. Together, the findings suggest ADCC is protective in the eye and that nonneutralizing antibodies elicited by ΔgD-2 provide greater protection than neutralizing antibodies elicited by rgD-2 against primary ocular HSV disease. The findings support advancement of vaccines, including ΔgD-2, that elicit polyfunctional antibody responses. IMPORTANCE Herpes simplex virus 1 is the leading cause of infectious corneal blindness in the United States and Europe. Developing vaccines to prevent ocular disease is challenging because the eye is a relatively immune-privileged site. In this study, we compared a single-cycle viral vaccine candidate, which is unique in that it elicits predominantly nonneutralizing antibodies that activate Fc receptors and bind complement, and a glycoprotein D subunit vaccine that elicits neutralizing but not Fc receptor-activating or complement-binding responses. Only the single-cycle vaccine provided both active and passive protection against a lethal ocular challenge. These findings greatly expand our understanding of the types of immune responses needed to protect the eye and will inform future prophylactic and therapeutic strategies.

scholarly journals A multicenter randomized trial to assess the efficacy of CONvalescent plasma therapy in patients with Invasive COVID-19 and acute respiratory failure treated with mechanical ventilation: the CONFIDENT trial protocol

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Benoît Misset ◽  
Eric Hoste ◽  
Anne-Françoise Donneau ◽  
David Grimaldi ◽  
Geert Meyfroidt ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Respiratory Failure ◽  
Neutralizing Antibodies ◽  
Ethical Issues ◽  
High Titer ◽  
Passive Immunization ◽  
University Hospital ◽  
Optimal Time ◽  
Relative Reduction ◽  
Number Of Patients

Abstract Background The COVID-19 pandemic reached Europe in early 2020. Convalescent plasma is used without a consistent evidence of efficacy. Our hypothesis is that passive immunization with plasma collected from patients having contracted COVID-19 and developed specific neutralizing antibodies may alleviate symptoms and reduce mortality in patients treated with mechanical ventilation for severe respiratory failure during the evolution of SARS-CoV-2 pneumonia. Methods We plan to include 500 adult patients, hospitalized in 16 Belgian intensive care units between September 2020 and 2022, diagnosed with SARS-CoV-2 pneumonia, under mechanical ventilation for less than 5 days and a clinical frailty scale less than 6. The study treatment will be compared to standard of care and allocated by randomization in a 1 to 1 ratio without blinding. The main endpoint will be mortality at day 28. We will perform an intention to treat analysis. The number of patients to include is based on an expected mortality rate at day 28 of 40 percent and an expected relative reduction with study intervention of 30 percent with α risk of 5 percent and β risk of 20 percent. Discussion This study will assess the efficacy of plasma in the population of mechanically ventilated patients. A stratification on the delay from mechanical ventilation and inclusion will allow to approach the optimal time use. Selecting convalescent plasmas with a high titer of neutralizing antibodies against SARS-CoV-2 will allow a homogeneous study treatment. The inclusion in the study is based on the consent of the patient or his/her legal representative, and the approval of the Investigational Review Board of the University hospital of Liège, Belgium. A data safety monitoring board (DSMB) has been implemented. Interim analyses have been planned at 100, 2002, 300 and 400 inclusions in order to decide whether the trail should be discontinued prematurely for ethical issues. We plan to publish our results in a peer-reviewed journal and to present them at national and international conferences. Funding and registration The trial is funded by the Belgian Health Care Knowledge Center KCE # COV201004 Trial registration Clinicaltrials.gov registration number NCT04558476. Registered 14 September 2020—Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04558476

scholarly journals Vaccination Route as a Determinant of Protective Antibody Responses against Herpes Simplex Virus

Vaccines ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 277
Author(s):  
Clare Burn Aschner ◽  
Carl Pierce ◽  
David M. Knipe ◽  
Betsy C. Herold
Keyword(s):  
Herpes Simplex ◽  
Neutralizing Antibodies ◽  
Lipid A ◽  
Low Dose ◽  
High Titer ◽  
Antibody Responses ◽  
Protein Vaccine ◽  
Herpes Simplex Viruses ◽  
Monophosphoryl Lipid A ◽  
Simplex Virus

Herpes simplex viruses (HSV) are significant global health problems associated with mucosal and neurologic disease. Prior experimental vaccines primarily elicited neutralizing antibodies targeting glycoprotein D (gD), but those that advanced to clinical efficacy trials have failed. Preclinical studies with an HSV-2 strain deleted in gD (ΔgD-2) administered subcutaneously demonstrated that it elicited a high titer, weakly neutralizing antibodies that activated Fcγ receptors to mediate antibody-dependent cellular cytotoxicity (ADCC), and completely protected mice against lethal disease and latency following vaginal or skin challenge with HSV-1 or HSV-2. Vaccine efficacy, however, may be impacted by dose and route of immunization. Thus, the current studies were designed to compare immunogenicity and efficacy following different routes of vaccination with escalating doses of ΔgD-2. We compared ΔgD-2 with two other candidates: recombinant gD protein combined with aluminum hydroxide and monophosphoryl lipid A adjuvants and a replication-defective virus deleted in two proteins involved in viral replication, dl5-29. Compared to the subcutaneous route, intramuscular and/or intradermal immunization resulted in increased total HSV antibody responses for all three vaccines and boosted the ADCC, but not the neutralizing response to ΔgD and dl5-29. The adjuvanted gD protein vaccine provided only partial protection and failed to elicit ADCC independent of route of administration. In contrast, the increased ADCC following intramuscular or intradermal administration of ΔgD-2 or dl5-29 translated into significantly increased protection. The ΔgD-2 vaccine provided 100% protection at doses as low as 5 × 104 pfu when administered intramuscularly or intradermally, but not subcutaneously. However, administration of a combination of low dose subcutaneous ΔgD-2 and adjuvanted gD protein resulted in greater protection than low dose ΔgD-2 alone indicating that gD neutralizing antibodies may contribute to protection. Taken together, these results demonstrate that ADCC provides a more predictive correlate of protection against HSV challenge in mice and support intramuscular or intradermal routes of vaccination.

scholarly journals Glycoprotein Exchange Vectors Based on Vesicular Stomatitis Virus Allow Effective Boosting and Generation of Neutralizing Antibodies to a Primary Isolate of Human Immunodeficiency Virus Type 1

2000 ◽  
Vol 74 (23) ◽  
pp. 10903-10910 ◽  
Author(s):  
Nina F. Rose ◽  
Anjeanette Roberts ◽  
Linda Buonocore ◽  
John K. Rose
Keyword(s):  
Human Immunodeficiency Virus ◽  
G Protein ◽  
Neutralizing Antibodies ◽  
High Titer ◽  
Primary Isolate ◽  
Effective Vaccine ◽  
Fourfold Increase ◽  
Immunodeficiency Virus ◽  
Vesicular Stomatitis ◽  
Hiv Envelope

ABSTRACT Live recombinant vesicular stomatitis viruses (VSVs) expressing foreign antigens are highly effective vaccine vectors. However, these vectors induce high-titer neutralizing antibody directed at the single VSV glycoprotein (G), and this antibody alone can prevent reinfection and boosting with the same vector. To determine if efficient boosting could be achieved by changing the G protein of the vector, we have developed two new recombinant VSV vectors based on the VSV Indiana serotype but with the G protein gene replaced with G genes from two other VSV serotypes, New Jersey and Chandipura. These G protein exchange vectors grew to titers equivalent to wild-type VSV and induced similar neutralizing titers to themselves but no cross-neutralizing antibodies to the other two serotypes. The effectiveness of these recombinant VSV vectors was illustrated in experiments in which sequential boosting of mice with the three vectors, all encoding the same primary human immunodeficiency virus (HIV) envelope protein, gave a fourfold increase in antibody titer to an oligomeric HIV envelope compared with the response in animals receiving the same vector three times. In addition, only the animals boosted with the exchange vectors produced antibodies neutralizing the autologous HIV primary isolate. These VSV envelope exchange vectors have potential as vaccines in immunizations when boosting of immune responses may be essential.

scholarly journals Development of equine antisera with high neutralizing activity against SARS-CoV-2

2020 ◽  
Author(s):  
Gajanan Sapkal ◽  
Anil Yadav ◽  
Gururaj Rao Deshpande ◽  
Pragya D. Yadav ◽  
Ketki Deshpande ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Passive Immunization ◽  
Cost Effective ◽  
Viral Disease ◽  
Effective Vaccine ◽  
Effective Treatment Option ◽  
Bacterial Diseases ◽  
Igg Binding ◽  
Effective Product

Abstract The pandemic of COVID -19 caused by SARS-CoV-2 is leading to a humongous impact on the mankind with over a million people succumbing to it worldwide. Although there are few drugs approved for the treatment, there is not yet a safe and effective vaccine available for COVID-19. Also, the passive immunization therapy with convalescent plasma, though potentially an effective treatment option for other viral disease has limitation of availability. The prior use of immunoglobulins generated in animals has proven to be effective in several viral and bacterial diseases. Here, we report the development and evaluation of equine hyper immune globulin raised against inactivated SARS-CoV-2 virus. Post immunization neutralization titres of the equines demonstrated high neutralizing antibodies. To minimize the adverse effects, the immunoglobulins were digested with pepsin, and purified to obtain the F(ab’)2 fragments. The average nAb titre of the purified bulk was 22,927 and correlated with high IgG binding efficiency in ELISA. The quality control assessments of the different batches proved to have consistent nAb titres. The study provides evidence of the potential of generating highly purified F(ab’)2 from equines against SARS-CoV-2 that can demonstrate consistent and high neutralization activity. Further, in-vivo testing for efficacy of this indigenously developed, cost effective product will pave the way to clinical evaluation.

scholarly journals Recombinant Modified Vaccinia Virus Ankara Expressing a Soluble Form of Glycoprotein B Causes Durable Immunity and Neutralizing Antibodies against Multiple Strains of Human Cytomegalovirus

2004 ◽  
Vol 78 (8) ◽  
pp. 3965-3976 ◽  
Author(s):  
Zhongde Wang ◽  
Corinna La Rosa ◽  
Rebecca Maas ◽  
Heang Ly ◽  
John Brewer ◽  
...  
Keyword(s):  
Vaccinia Virus ◽  
Human Cytomegalovirus ◽  
Neutralizing Antibodies ◽  
Natural Infection ◽  
Glycoprotein B ◽  
Soluble Form ◽  
Effective Vaccine ◽  
Viral Pathogen ◽  
Modified Vaccinia Virus Ankara ◽  
Viral Vaccine

ABSTRACT Human cytomegalovirus (CMV) is a viral pathogen that infects both genders, who remain asymptomatic unless they receive immunosuppressive drugs or acquire infections that cause reactivation of latent virus. CMV infection also causes serious birth defects following primary maternal infection during gestation. A safe and effective vaccine to limit disease in this population continues to be elusive. A well-studied antigen is glycoprotein B (gB), which is the principal target of neutralizing antibodies (NAb) towards CMV in humans and has been implicated as the viral partner in the receptor-mediated infection by CMV in a variety of cell types. Antibody-mediated virus neutralization has been proposed as a mechanism by which host immunity could modify primary infection. Towards this goal, an attenuated poxvirus, modified vaccinia virus Ankara (MVA), has been constructed to express soluble CMV gB (gB680-MVA) to induce CMV NAb. Very high levels of gB-specific CMV NAb were produced after two doses of the viral vaccine. NAb were durable within a twofold range for up to 6 months. Neutralization titers developed in immunized mice are equivalent to titers found clinically after natural infection. This viral vaccine, expressing gB derived from CMV strain AD169, induced antibodies that neutralized CMV strains of three different genotypes. Remarkably, preexisting MVA and vaccinia virus (poxvirus) immunity did not interfere with subsequent immunizations of gB680-MVA. The safety characteristics of MVA, combined with the robust immune response to CMV gB, suggest that this approach could be rapidly translated into the clinic.

scholarly journals Maternal Immunization with a Single-Cycle Herpes Simplex Virus (HSV) Candidate Vaccine, ΔgD-2, Protects Neonatal Mice from Lethal Viral Challenge

2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S22-S22 ◽  
Author(s):  
Carol Kao ◽  
Clare Burn ◽  
William R Jacobs ◽  
Betsy C Herold
Keyword(s):  
High Titer ◽  
Lethal Dose ◽  
Passive Transfer ◽  
Immune Serum ◽  
Single Cycle ◽  
Research Support ◽  
Maternal Immunization ◽  
Neonatal Mice ◽  
Adult Mice ◽  
Hsv 1

Abstract Background Perinatal HSV is associated with ~60% mortality if untreated and with substantial morbidity even with appropriate therapy. We recently engineered a single-cycle virus deleted in glycoprotein-D (ΔgD-2) that induces high-titer antibodies (Abs) that are non-neutralizing but activate the Fc receptor (FcR) to elicit antibody-dependent cellular cytotoxicity (ADCC). Immunization with ΔgD-2 completely protects adult mice from HSV-1 and HSV-2 disease following vaginal, skin, intraocular, or intranasal challenge and prevents the establishment of latency (ELife, 2014, JCI Insight, 2016). Thus we hypothesize that maternal immunization with ΔgD-2 and/or passive transfer of immune serum will protect neonates from HSV. Methods Four- to 6-week-old C57Bl/6 female mice were primed and boosted at 3-week intervals with ΔgD-2 or an equal volume of uninfected cell lysates (VD60 cells). Two weeks post-boost, mice were mated and pups were challenged with a lethal dose of HSV-1 (Bx31.1) at day 7 of birth. To differentiate the contribution of transplacental vs. colostrum Abs, mothers were switched at birth. Alternatively, 7-day-old mice born to nonimmunized mothers received a single dose of immune serum (400 μg total Ab) intraperitoneally at time of intranasal challenge. Results Thirty-eight of 47 (81%) of the pups born to and nursed by ΔgD-2-immunized mothers survived, exhibited little or no signs of disease and were protected from latency as measured by quantifying HSV DNA by PCR in neuronal tissue. In contrast, 12/14 (86%) of pups born to control vaccinated and nursed mice developed neurological signs of disease and died (P < 0.0001, Fisher’s exact test). Survival was associated with increased ADCC Abs in the serum of neonatal mice. In contrast, passive transfer of immune serum, which consistently protects adult mice from infection, did not protect neonates. If newborns born to immunized mice suckled with control mice, protection was partially abrogated (11/19, 58% survival), suggesting that both systemic and mucosal Abs are required for complete protection. Conclusion Maternal vaccination with ΔgD-2 provides significant protection against intranasal neonatal challenge but may require exposure to systemic and mucosal Abs. Disclosures W. R. Jacobs Jr., xvax: Scientific Advisor, Research support; B. C. Herold, X-vax: Grant Investigator, Research grant and Research support

scholarly journals Production of equine sera as a potential immunotherapy against COVID-19

2021 ◽  
Vol 62 ◽  
pp. 3-17
Author(s):  
Mariana V Cepeda ◽  
Juan C. Jiménez ◽  
Flor H. Pujol ◽  
Héctor R. Rangel ◽  
Carlos Bello ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Passive Immunization ◽  
Viral Disease ◽  
High Titre ◽  
Immune Serum ◽  
Receptor Binding Domain ◽  
Emerging Viruses ◽  
Protein Receptor ◽  
Equine Plasma ◽  
Elisa Titre

Emerging viruses such as the COVID-19-inducing virus, SARSCoV- 2, represent a threat to human health, unless effective vaccines, drugs or alternative treatments, such as passive immunization, become accessible. Animal-derived immunoglobulins, such as equine immunoglobulins might be useful as immunoprophylaxis or immunotherapy against this viral disease. Therapeutic antibodies (Abs) for SARS-CoV-2 were obtained from hyperimmune equine plasma using the Spike protein receptor binding domain (RBD) as an immunogen. The presence of anti-RBD antibodies was evaluated by ELISA and the titres of neutralizing antibodies were determined in viral cell culture. Immunized horses generated high-titre of anti-RBD antibodies with antiviral neutralizing activity on Vero-E6 cells of 1/1,000. To minimize potential adverse effects, the immunoglobulins were digested with pepsin, and purified to obtain the F(ab’)2 fragments with the protocol standardized by Biotecfar C.A for the production of snake antivenom. Pre-immune serum displayed an unexpected anti-RBD reactivity by ELISA (titre up to 1/900) and Western Blot, but no angioneutralizing activity. Modelling of the RBD of equine coronavirus showed that some of the known epitopes of SARS-CoV-2 RBD were structurally conserved in the equine coronavirus protein. This might suggest that some of the reactivity observed in the pre-immune serum to the SARS-CoV-2 RBD might be due to a previous exposure to equine coronavirus.

scholarly journals Protective Transfer: Maternal passive immunization with a rotavirus-neutralizing dimeric IgA protects against rotavirus disease in suckling neonates

2021 ◽  
Author(s):  
SN Langel ◽  
JT Steppe ◽  
J Chang ◽  
T Travieso ◽  
H Webster ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Passive Immunization ◽  
Systemic Administration ◽  
Secretory Iga ◽  
Effective Vaccine ◽  
Dependent Manner ◽  
Middle Income ◽  
Middle Income Countries ◽  
Enteric Infections ◽  
Developed Nations

SUMMARYBreast milk secretory IgA antibodies provide a first line of defense against enteric infections. Despite this and an effective vaccine, human rotaviruses (RVs) remain the leading cause of severe infectious diarrhea in children in low- and middle-income countries (LMIC) where vaccine efficacy is lower than that of developed nations. Therapeutic strategies that deliver potently neutralizing antibodies into milk could provide protection against enteric pathogens such as RVs. We developed a murine model of maternal protective-transfer using systemic administration of a dimeric IgA (dIgA) monoclonal antibody. We confirmed that systemically-administered dIgA passively transferred into milk and stomach of suckling pups in a dose-dependent manner. We then demonstrated that systemic administration of an engineered potent RV-neutralizing dIgA (mAb41) in lactating dams protected suckling pups from RV-induced diarrhea. This maternal protective-transfer immunization platform could be an effective strategy to improve infant mortality against enteric infections, particularly in LMIC with high rates of breastfeeding.GRAPHICAL ABSTRACT

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