scholarly journals Serum Immune Responses to the Proteins of Porcine Reproductive and Respiratory Syndrome (PRRS) Virus

1994 ◽  
Vol 6 (4) ◽  
pp. 410-415 ◽  
Author(s):  
Eric A. Nelson ◽  
Jane Christopher-Hennings ◽  
David A. Benfield
Keyword(s):  
Immune Responses ◽  
Indirect Immunofluorescence ◽  
Neutralizing Antibodies ◽  
Virus Isolate ◽  
Neutralizing Antibody ◽  
Viral Proteins ◽  
Antibody Responses ◽  
Virus Neutralization ◽  
Respiratory Syndrome Virus ◽  
Prrs Virus

The antibody responses of pigs to porcine reproductive and respiratory syndrome virus (isolate VR-2332) were evaluated by indirect immunofluorescence, virus neutralization, and immunoblotting. All pigs in each group were positive by indirect immunofluorescence 14-21 days postexposure (DPE), and antibodies to specific viral proteins (15, 19 or 26 kD) were initially demonstrated by immunoblotting at 7–21 days DPE. Neutralizing antibodies were detected in only 2 pigs that were inoculated intranasally and given additional parenteral injections with adjuvant. These antibodies appeared much later, 51–70 DPE, than did antibodies detected by indirect immunofluorescence. The titer of the neutralizing antibodies increased until 127 DPE, after which the titers decreased, and 1 animal became seronegative for neutralizing antibody by 262 DPE.

scholarly journals Comparison of Host Immune Responses to Homologous and Heterologous Type II Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) Challenge in Vaccinated and Unvaccinated Pigs

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
X. Li ◽  
A. Galliher-Beckley ◽  
L. Pappan ◽  
B. Trible ◽  
M. Kerrigan ◽  
...  
Keyword(s):  
Immune Responses ◽  
Neutralizing Antibodies ◽  
Expression Profiles ◽  
Neutralizing Antibody ◽  
Respiratory Syndrome Virus ◽  
Host Immune Responses ◽  
Prrs Virus ◽  
Heterologous Challenge ◽  
Homologous Virus ◽  
Antibody Titers

Porcine reproductive and respiratory syndrome (PRRS) is a high-consequence animal disease with current vaccines providing limited protection from infection due to the high degree of genetic variation of field PRRS virus. Therefore, understanding host immune responses elicited by different PRRSV strains will facilitate the development of more effective vaccines. Using IngelVac modified live PRRSV vaccine (MLV), its parental strain VR-2332, and the heterologous KS-06-72109 strain (a Kansas isolate of PRRSV), we compared immune responses induced by vaccination and/or PRRSV infection. Our results showed that MLV can provide complete protection from homologous virus (VR-2332) and partial protection from heterologous (KS-06) challenge. The protection was associated with the levels of PRRSV neutralizing antibodies at the time of challenge, with vaccinated pigs having higher titers to VR-2332 compared to KS-06 strain. Challenge strain did not alter the cytokine expression profiles in the serum of vaccinated pigs or subpopulations of T cells. However, higher frequencies of IFN-γ-secreting PBMCs were generated from pigs challenged with heterologous PRRSV in a recall response when PBMCs were re-stimulated with PRRSV. Thus, this study indicates that serum neutralizing antibody titers are associated with PRRSV vaccination-induced protection against homologous and heterologous challenge.

scholarly journals Immunogenicity, safety, and efficacy of sequential immunizations with an SIV-based IDLV expressing CH505 Envs

npj Vaccines ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Maria Blasi ◽  
Donatella Negri ◽  
Kevin O. Saunders ◽  
Erich J. Baker ◽  
Hannah Stadtler ◽  
...  
Keyword(s):  
Immune Responses ◽  
Neutralizing Antibodies ◽  
Lentiviral Vector ◽  
Rhesus Macaques ◽  
Infected Individual ◽  
Neutralizing Antibody ◽  
Antibody Responses ◽  
Safety And Efficacy ◽  
Env Protein ◽  
Hiv 1

AbstractA preventative HIV-1 vaccine is an essential intervention needed to halt the HIV-1 pandemic. Neutralizing antibodies protect against HIV-1 infection in animal models, and thus an approach toward a protective HIV-1 vaccine is to induce broadly cross-reactive neutralizing antibodies (bnAbs). One strategy to achieve this goal is to define envelope (Env) evolution that drives bnAb development in infection and to recreate those events by vaccination. In this study, we report the immunogenicity, safety, and efficacy in rhesus macaques of an SIV-based integrase defective lentiviral vector (IDLV) expressing sequential gp140 Env immunogens derived from the CH505 HIV-1-infected individual who made the CH103 and CH235 bnAb lineages. Immunization with IDLV expressing sequential CH505 Envs induced higher magnitude and more durable binding and neutralizing antibody responses compared to protein or DNA +/− protein immunizations using the same sequential envelopes. Compared to monkeys immunized with a vector expressing Envs alone, those immunized with the combination of IDLV expressing Env and CH505 Env protein demonstrated improved durability of antibody responses at six months after the last immunization as well as lower peak viremia and better virus control following autologous SHIV-CH505 challenge. There was no evidence of vector mobilization or recombination in the immunized and challenged monkeys. Although the tested vaccines failed to induce bnAbs and to mediate significant protection following SHIV-challenge, our results show that IDLV proved safe and successful at inducing higher titer and more durable immune responses compared to other vaccine platforms.

scholarly journals Biochemical and Immunogenic Characterization of Soluble Human Immunodeficiency Virus Type 1 Envelope Glycoprotein Trimers Expressed by Semliki Forest Virus

2005 ◽  
Vol 79 (17) ◽  
pp. 10902-10914 ◽  
Author(s):  
Mattias N. E. Forsell ◽  
Yuxing Li ◽  
Maria Sundbäck ◽  
Krisha Svehla ◽  
Peter Liljeström ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Immune Responses ◽  
Envelope Glycoprotein ◽  
Neutralizing Antibodies ◽  
Semliki Forest Virus ◽  
Neutralizing Antibody ◽  
Antibody Responses ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT The current lack of envelope glycoprotein immunogens that elicit broadly neutralizing antibody responses remains a major challenge for human immunodeficiency virus type 1 (HIV-1) vaccine development. However, the recent design and construction of stable soluble gp140 trimers have shown that some neutralization breadth can be achieved by using immunogens that better mimic the functional viral spike complex. The use of genetic delivery systems to drive the in vivo expression of such immunogens for the stimulation of neutralizing antibodies against HIV-1 may offer advantages by maintaining the quaternary structure of the trimeric envelope glycoproteins. Here, we describe the biochemical and immunogenic properties of soluble HIV-1 envelope glycoprotein trimers expressed by recombinant Semliki Forest virus (rSFV). The results presented here demonstrate that rSFV supports the expression of stable soluble gp140 trimers that retain recognition by conformationally sensitive antibodies. Further, we show that rSFV particle immunizations efficiently primed immune responses as measured after a single boost with purified trimeric gp140 protein, resulting in a Th1-biased antibody response. This differed from the Th2-biased antibody response obtained after repeated immunizations with purified gp140 protein trimers. Despite this difference, both regimens stimulated neutralizing antibody responses of similar potency. This suggests that rSFV may be a useful component of a viral vector prime-protein boost regimen aimed at stimulating both cell-mediated immune responses and neutralizing antibodies against HIV-1.

scholarly journals Immunogenicity of Multiple Doses of pDNA Vaccines against SARS-CoV-2

2021 ◽  
Vol 14 (1) ◽  
pp. 39
Author(s):  
Iman Almansour ◽  
Nabela Calamata Macadato ◽  
Thamer Alshammari
Keyword(s):  
Immune Responses ◽  
Neutralizing Antibodies ◽  
Natural Infection ◽  
Neutralizing Antibody ◽  
Serum Levels ◽  
Antibody Responses ◽  
Limited Data ◽  
Effective Measure ◽  
Vaccine Candidates ◽  
Cellular Immune

Since its identification in Wuhan, China, in December 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), has resulted in 46 million cases and more than one million deaths worldwide, as of 30 October 2020. Limited data exist on the magnitude and durability of antibodies generated by natural infection with SARS-CoV-2 and whether they can provide long-lasting immunity from reinfection. Vaccination has proven the most effective measure for controlling and preventing pandemics and, thus, development of a vaccine against COVID-19 is a top priority. However, the doses required to induce effective, long-lasting antibody responses against SARS-CoV-2 remain undetermined. Here, we present the development of SARS-CoV-2 vaccine candidates encoding the viral spike (S) gene, generated using plasmid (p)DNA technology, and we demonstrate the eliciting of S-specific antibodies in mice after three and four doses. The magnitude of binding and neutralizing antibody responses with three doses of synthetic, codon-optimized, full-length S (S.opt.FL) vaccine is comparable to that generated after four doses, suggesting that three doses are sufficient to elicit robust immune responses. Conversely, four doses of S1.opt pDNA vaccine, containing the S globular head, are required to elicit high levels of neutralizing antibodies. Furthermore, the S.opt.FL pDNA vaccine induces the highest serum levels of interferon (IFN)-γ, a marker for activation of cellular immune responses. Overall, our data show that three doses of S.FL pDNA vaccine elicit potent neutralizing antibody responses, with preclinical data that support the immunogenicity of these COVID-19 vaccine candidates and provide justification for further translational studies.

scholarly journals SARS-CoV-2 vaccination induces neutralizing antibodies against pandemic and pre-emergent SARS-related coronaviruses in monkeys

2021 ◽  
Author(s):  
Kevin O. Saunders ◽  
Esther Lee ◽  
Robert Parks ◽  
David R. Martinez ◽  
Dapeng Li ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Immune Responses ◽  
Neutralizing Antibodies ◽  
Geometric Mean ◽  
Neutralizing Antibody ◽  
Antibody Responses ◽  
Receptor Binding Domain ◽  
Neutralization Titer ◽  
The Uk ◽  
Further Development

SUMMARYBetacoronaviruses (betaCoVs) caused the severe acute respiratory syndrome (SARS) and Middle East Respiratory Syndrome (MERS) outbreaks, and now the SARS-CoV-2 pandemic. Vaccines that elicit protective immune responses against SARS-CoV-2 and betaCoVs circulating in animals have the potential to prevent future betaCoV pandemics. Here, we show that immunization of macaques with a multimeric SARS-CoV-2 receptor binding domain (RBD) nanoparticle adjuvanted with 3M-052-Alum elicited cross-neutralizing antibody responses against SARS-CoV-1, SARS-CoV-2, batCoVs and the UK B.1.1.7 SARS-CoV-2 mutant virus. Nanoparticle vaccination resulted in a SARS-CoV-2 reciprocal geometric mean neutralization titer of 47,216, and robust protection against SARS-CoV-2 in macaque upper and lower respiratory tracts. Importantly, nucleoside-modified mRNA encoding a stabilized transmembrane spike or monomeric RBD protein also induced SARS-CoV-1 and batCoV cross-neutralizing antibodies, albeit at lower titers. These results demonstrate current mRNA vaccines may provide some protection from future zoonotic betaCoV outbreaks, and provide a platform for further development of pan-betaCoV nanoparticle vaccines.

scholarly journals Marburg virus survivor immune responses are Th1 skewed with limited neutralizing antibody responses

2017 ◽  
Vol 214 (9) ◽  
pp. 2563-2572 ◽  
Author(s):  
Spencer W. Stonier ◽  
Andrew S. Herbert ◽  
Ana I. Kuehne ◽  
Ariel Sobarzo ◽  
Polina Habibulin ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Ebola Virus ◽  
T Cell Responses ◽  
Neutralizing Antibody ◽  
Cd8 T Cell ◽  
Marburg Virus ◽  
Antibody Responses ◽  
Cd4 T Cell ◽  
Cell Responses

Until recently, immune responses in filovirus survivors remained poorly understood. Early studies revealed IgM and IgG responses to infection with various filoviruses, but recent outbreaks have greatly expanded our understanding of filovirus immune responses. Immune responses in survivors of Ebola virus (EBOV) and Sudan virus (SUDV) infections have provided the most insight, with T cell responses as well as detailed antibody responses having been characterized. Immune responses to Marburg virus (MARV), however, remain almost entirely uncharacterized. We report that immune responses in MARV survivors share characteristics with EBOV and SUDV infections but have some distinct differences. MARV survivors developed multivariate CD4+ T cell responses but limited CD8+ T cell responses, more in keeping with SUDV survivors than EBOV survivors. In stark contrast to SUDV survivors, rare neutralizing antibody responses in MARV survivors diminished rapidly after the outbreak. These results warrant serious consideration for any vaccine or therapeutic that seeks to be broadly protective, as different filoviruses may require different immune responses to achieve immunity.

scholarly journals Characterization of Neutralizing Antibody Responses Elicited by Clade A Envelope Immunogens Derived from Early Transmitted Viruses

2008 ◽  
Vol 82 (12) ◽  
pp. 5912-5921 ◽  
Author(s):  
Zane Kraft ◽  
Katharine Strouss ◽  
William F. Sutton ◽  
Brad Cleveland ◽  
For Yue Tso ◽  
...  
Keyword(s):  
Chronic Infection ◽  
Neutralizing Antibodies ◽  
Acute Infection ◽  
Variable Region ◽  
Neutralizing Antibody ◽  
Antibody Responses ◽  
Virus Envelope ◽  
Variable Regions ◽  
Clade B ◽  
Region Length

ABSTRACT The vast majority of studies with candidate immunogens based on the human immunodeficiency virus envelope (Env) have been conducted with Env proteins derived from clade B viruses isolated during chronic infection. Whether non-clade B Env protein immunogens will elicit antibodies with epitope specificities that are similar to those of antibodies elicited by clade B Envs and whether the antibodies elicited by Envs derived from early transmitted viruses will be similar to those elicited by Envs derived from viruses isolated during chronic infection are currently unknown. Here we performed immunizations with four clade A Envs, cloned directly from the peripheral blood of infected individuals during acute infection, which differed in lengths and extents of glycosylation. The antibody responses elicited by these four Envs were compared to each other and to those elicited by a well-characterized clade B Env immunogen derived from the SF162 virus, which was isolated during chronic infection. Only one clade A Env, the one with the fewer glycosylation sites, elicited homologous neutralizing antibodies (NAbs); these did not target the V1, V2, or V3 regions. In contrast, all four clade A Envs elicited anti-V3 NAbs against “easy-to-neutralize” clade B and clade A isolates, irrespective of the variable region length and extent of glycosylation of the Env used as an immunogen. These anti-V3 NAbs did not access their epitopes on homologous and heterologous clade A, or B, neutralization-resistant viruses. The length and extent of glycosylation of the variable regions on the clade A Env immunogens tested did not affect the breadth of the elicited NAbs. Our data also indicate that the development of cross-reactive NAbs against clade A viruses faces similar hurdles to the development of cross-reactive anti-clade B NAbs.

scholarly journals Contrasting Adult and Infant Immune Responses to HIV Infection and Vaccination

2015 ◽  
Vol 23 (2) ◽  
pp. 84-94 ◽  
Author(s):  
David R. Martinez ◽  
Sallie R. Permar ◽  
Genevieve G. Fouda
Keyword(s):  
Immune Responses ◽  
Hiv Infection ◽  
Vaccine Efficacy ◽  
Neutralizing Antibody ◽  
Hiv Vaccine ◽  
Antibody Responses ◽  
Hiv Vaccines ◽  
Vaccine Candidates ◽  
Protective Antibodies ◽  
Pediatric Populations

ABSTRACTExtensive studies have demonstrated that infant immune responses are distinct from those of adults. Despite these differences, infant immunization can elicit protective immune responses at levels comparable to or, in some cases, higher than adult immune responses to many vaccines. To date, only a few HIV vaccine candidates have been tested in infant populations, and none of them evaluated vaccine efficacy. Recent exciting studies showing that HIV-infected infants can develop broad neutralizing antibody responses and that some HIV vaccine regimens can elicit high levels of potentially protective antibodies in infants provide support for the development and testing of HIV vaccines in pediatric populations. In this review, we discuss the differences in adult and infant immune responses in the setting of HIV infection and vaccination.

scholarly journals The vaccinia-based Sementis Copenhagen Vector COVID-19 vaccine induces broad and durable cellular and humoral immune responses

2021 ◽  
Author(s):  
Preethi Eldi ◽  
Tamara H Cooper ◽  
Natalie A Prow ◽  
Liang Liu ◽  
Gary K Heinemann ◽  
...  
Keyword(s):  
Immune Responses ◽  
Neutralizing Antibodies ◽  
First Generation ◽  
Neutralizing Antibody ◽  
Immune Memory ◽  
Antibody Activity ◽  
Post Vaccination ◽  
Humoral Immune ◽  
Humoral Immune Responses ◽  
Heterologous Boost

The ongoing COVID-19 pandemic perpetuated by SARS-CoV-2 variants, has highlighted the continued need for broadly protective vaccines that elicit robust and durable protection. Here, the vaccinia virus-based, replication-defective Sementis Copenhagen Vector (SCV) was used to develop a first-generation COVID-19 vaccine encoding the spike glycoprotein (SCV-S). Vaccination of mice rapidly induced polyfunctional CD8 T cells with cytotoxic activity and robust Th1-biased, spike-specific neutralizing antibodies, which are significantly increased following a second vaccination, and contained neutralizing activity against the alpha and beta variants of concern. Longitudinal studies indicated neutralizing antibody activity was maintained up to 9 months post-vaccination in both young and aging mice, with durable immune memory evident even in the presence of pre-existing vector immunity. This immunogenicity profile suggests a potential to expand protection generated by current vaccines in a heterologous boost format, and presents a solid basis for second-generation SCV-based COVID-19 vaccine candidates incorporating additional SARS-CoV-2 immunogens.

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