scholarly journals Induction of Broad-Based Immunity and Protective Efficacy by Self-amplifying mRNA Vaccines Encoding Influenza Virus Hemagglutinin

2015 ◽  
Vol 90 (1) ◽  
pp. 332-344 ◽  
Author(s):  
Michela Brazzoli ◽  
Diletta Magini ◽  
Alessandra Bonci ◽  
Scilla Buccato ◽  
Cinzia Giovani ◽  
...  

ABSTRACTSeasonal influenza is a vaccine-preventable disease that remains a major health problem worldwide, especially in immunocompromised populations. The impact of influenza disease is even greater when strains drift, and influenza pandemics can result when animal-derived influenza virus strains combine with seasonal strains. In this study, we used the SAM technology and characterized the immunogenicity and efficacy of a self-amplifying mRNA expressing influenza virus hemagglutinin (HA) antigen [SAM(HA)] formulated with a novel oil-in-water cationic nanoemulsion. We demonstrated that SAM(HA) was immunogenic in ferrets and facilitated containment of viral replication in the upper respiratory tract of influenza virus-infected animals. In mice, SAM(HA) induced potent functional neutralizing antibody and cellular immune responses, characterized by HA-specific CD4 T helper 1 and CD8 cytotoxic T cells. Furthermore, mice immunized with SAM(HA) derived from the influenza A virus A/California/7/2009 (H1N1) strain (Cal) were protected from a lethal challenge with the heterologous mouse-adapted A/PR/8/1934 (H1N1) virus strain (PR8). Sera derived from SAM(H1-Cal)-immunized animals were not cross-reactive with the PR8 virus, whereas cross-reactivity was observed for HA-specific CD4 and CD8 T cells. Finally, depletion of T cells demonstrated that T-cell responses were essential in mediating heterologous protection. If the SAM vaccine platform proves safe, well tolerated, and effective in humans, the fully synthetic SAM vaccine technology could provide a rapid response platform to control pandemic influenza.IMPORTANCEIn this study, we describe protective immune responses in mice and ferrets after vaccination with a novel HA-based influenza vaccine. This novel type of vaccine elicits both humoral and cellular immune responses. Although vaccine-specific antibodies are the key players in mediating protection from homologous influenza virus infections, vaccine-specific T cells contribute to the control of heterologous infections. The rapid production capacity and the synthetic origin of the vaccine antigen make the SAM platform particularly exploitable in case of influenza pandemic.

2018 ◽  
Vol 93 (3) ◽  
Author(s):  
Cindy Nürnberger ◽  
Bianca S. Bodmer ◽  
Anna H. Fiedler ◽  
Gülsah Gabriel ◽  
Michael D. Mühlebach

ABSTRACTThe impact of the Zika virus (ZIKV) epidemic highlights the need for vaccines that reduce or prevent infection and reliably prevent teratogenic complications. The live-attenuated measles virus (MV) vaccine strains are a promising vaccine platform, since they induce robust humoral and cellular immune responses against additional antigens and have an excellent safety record. To explore its potential to protect against ZIKV, we compared a recombinant Schwarz strain MV that encodes ZIKV prM and soluble E proteins (MV-Zika-sE) with a prototypic alum-adjuvanted whole inactivated ZIKV particle vaccine. Analysis of MV-Zika-sE-infected cells confirmed antigen expression, and the virus replicated with vaccine strain characteristics. Immunized IFNAR−/−-CD46Ge mice developed E protein-specific and neutralizing antibodies, and ZIKV E-specific cellular immune responses were observed by gamma interferon (IFN-γ) enzyme-linked immunospot (ELISpot) andin vitroT cell proliferation assays. To analyze protective efficacy, vaccinated female mice were challenged with ZIKV after allogeneic mating. In MV-Zika-sE-vaccinated mice, weight gain was similar to that in uninfected mice, while no plasma viremia was detectable in the majority of the animals. In contrast, infected control animals gained less weight and experienced about 100-fold higher viremia over at least 3 days. Moreover, vaccination with MV-Zika-sE reduced the ZIKV load in different organs and the placentas and prevented infection of the fetus. Consequently, no fetal growth retardation, anemia, or death due to ZIKV infection was seen in MV-Zika-sE-vaccinated dams. In contrast, the inactivated ZIKV vaccine had little to no effect in our studies. Therefore, the MV-derived ZIKV vaccine is a promising candidate for further preclinical and clinical development.IMPORTANCEZika virus (ZIKV) is a mosquito-borne flavivirus that causes a variety of neurological complications, including congenital birth defects. Despite the urgent need, no ZIKV vaccine has yet been licensed. Recombinant vaccine strain-derived measles viruses (MV) constitute a promising vector platform to induce immunity against foreign pathogens by expressing antigens from additional transcription units while at the same time possessing a remarkable safety profile. This concept has already been validated against different pathogens, including at least 3 other flaviviruses, and our data show that vaccination with MV expressing soluble ZIKV E protein significantly diminishes infection and prevents fetal loss or damage in an allogeneic mouse pregnancy model. It can thus be regarded as a promising emergency vaccine candidate with the potential for inclusion in routine vaccination settings in areas of endemicity to prevent teratogenic effects of circulating ZIKV during pregnancy, comparable to standard rubella virus vaccination.


Blood ◽  
2003 ◽  
Vol 101 (3) ◽  
pp. 807-814 ◽  
Author(s):  
James W. Lillard ◽  
Udai P. Singh ◽  
Prosper N. Boyaka ◽  
Shailesh Singh ◽  
Dennis D. Taub ◽  
...  

AbstractMacrophage inflammatory protein-1α (MIP-1α) and MIP-1β are distinct but highly homologous CC chemokines produced by a variety of host cells in response to various external stimuli and share affinity for CCR5. To better elucidate the role of these CC chemokines in adaptive immunity, we have characterized the affects of MIP-1α and MIP-1β on cellular and humoral immune responses. MIP-1α stimulated strong antigen (Ag)–specific serum immunoglobulin G (IgG) and IgM responses, while MIP-1β promoted lower IgG and IgM but higher serum IgA and IgE antibody (Ab) responses. MIP-1α elevated Ag-specific IgG1 and IgG2b followed by IgG2a and IgG3 subclass responses, while MIP-1β only stimulated IgG1 and IgG2b subclasses. Correspondingly, MIP-1β produced higher titers of Ag-specific mucosal secretory IgA Ab levels when compared with MIP-1α. Splenic T cells from MIP-1α– or MIP-1β–treated mice displayed higher Ag-specific Th1 (interferon-γ [IFN-γ]) as well as selective Th2 (interleukin-5 [IL-5] and IL-6) cytokine responses than did T cells from control groups. Interestingly, mucosally derived T cells from MIP-1β–treated mice displayed higher levels of IL-4 and IL-6 compared with MIP-1α–treated mice. However, MIP-1α effectively enhanced Ag-specific cell-mediated immune responses. In correlation with their selective effects on humoral and cellular immune responses, these chemokines also differentially attract CD4+ versus CD8+ T cells and modulate CD40, CD80, and CD86 expressed by B220+ cells as well as CD28, 4-1BB, and gp39 expression by CD4+ and CD8+ T cells in a dose-dependent fashion. Taken together, these studies suggest that these CC chemokines differentially enhance mucosal and serum humoral as well as cellular immune responses.


eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Helen Parry ◽  
Gokhan Tut ◽  
Rachel Bruton ◽  
Sian Faustini ◽  
Christine Stephens ◽  
...  

Age is the major risk factor for mortality after SARS-CoV-2 infection and older people have received priority consideration for COVID-19 vaccination. However, vaccine responses are often suboptimal in this age group and few people over the age of 80 years were included in vaccine registration trials. We determined the serological and cellular response to spike protein in 100 people aged 80–96 years at 2 weeks after the second vaccination with the Pfizer BNT162b2 mRNA vaccine. Antibody responses were seen in every donor with high titers in 98%. Spike-specific cellular immune responses were detectable in only 63% and correlated with humoral response. Previous SARS-CoV-2 infection substantially increased antibody responses after one vaccine and antibody and cellular responses remained 28-fold and 3-fold higher, respectively, after dual vaccination. Post-vaccine sera mediated strong neutralization of live Victoria infection and although neutralization titers were reduced 14-fold against the P.1 variant first discovered in Brazil they remained largely effective. These data demonstrate that the mRNA vaccine platform delivers strong humoral immunity in people up to 96 years of age and retains broad efficacy against the P.1 variant of concern.


Vaccines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1409
Author(s):  
Wasim A. Prates-Syed ◽  
Lorena C. S. Chaves ◽  
Karin P. Crema ◽  
Larissa Vuitika ◽  
Aline Lira ◽  
...  

Virus-like particles (VLPs) are a versatile, safe, and highly immunogenic vaccine platform. Recently, there are developmental vaccines targeting SARS-CoV-2, the causative agent of COVID-19. The COVID-19 pandemic affected humanity worldwide, bringing out incomputable human and financial losses. The race for better, more efficacious vaccines is happening almost simultaneously as the virus increasingly produces variants of concern (VOCs). The VOCs Alpha, Beta, Gamma, and Delta share common mutations mainly in the spike receptor-binding domain (RBD), demonstrating convergent evolution, associated with increased transmissibility and immune evasion. Thus, the identification and understanding of these mutations is crucial for the production of new, optimized vaccines. The use of a very flexible vaccine platform in COVID-19 vaccine development is an important feature that cannot be ignored. Incorporating the spike protein and its variations into VLP vaccines is a desirable strategy as the morphology and size of VLPs allows for better presentation of several different antigens. Furthermore, VLPs elicit robust humoral and cellular immune responses, which are safe, and have been studied not only against SARS-CoV-2 but against other coronaviruses as well. Here, we describe the recent advances and improvements in vaccine development using VLP technology.


Vaccines ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 126
Author(s):  
Lilin Lai ◽  
Nadine Rouphael ◽  
Yongxian Xu ◽  
Amy C. Sherman ◽  
Srilatha Edupuganti ◽  
...  

The cellular immune responses elicited by an investigational vaccine against an emergent variant of influenza (H3N2v) are not fully understood. Twenty-five subjects, enrolled in an investigational influenza A/H3N2v vaccine study, who received two doses of vaccine 21 days apart, were included in a sub-study of cellular immune responses. H3N2v-specific plasmablasts were determined by ELISpot 8 days after each vaccine dose and H3N2v specific CD4+ T cells were quantified by intracellular cytokine and CD154 (CD40 ligand) staining before vaccination, 8 and 21 days after each vaccine dose. Results: 95% (19/20) and 96% (24/25) subjects had pre-existing H3N2v specific memory B, and T cell responses, respectively. Plasmablast responses at Day 8 after the first vaccine administration were detected against contemporary H3N2 strains and correlated with hemagglutination inhibition HAI (IgG: p = 0.018; IgA: p < 0.001) and Neut (IgG: p = 0.038; IgA: p = 0.021) titers and with memory B cell frequency at baseline (IgA: r = 0.76, p < 0.001; IgG: r = 0.74, p = 0.0001). The CD4+ T cells at Days 8 and 21 expanded after prime vaccination and this expansion correlated strongly with early post-vaccination HAI and Neut titers (p ≤ 0.002). In an adult population, the rapid serological response observed after initial H3N2v vaccination correlates with post-vaccination plasmablasts and CD4+ T cell responses.


Hepatology ◽  
2004 ◽  
Vol 40 (6) ◽  
pp. 1459-1461
Author(s):  
Paul Klenerman ◽  
Nasser Semmo ◽  
Scott Ward

2002 ◽  
Vol 76 (12) ◽  
pp. 6093-6103 ◽  
Author(s):  
Eishiro Mizukoshi ◽  
Michelina Nascimbeni ◽  
Joshua B. Blaustein ◽  
Kathleen Mihalik ◽  
Charles M. Rice ◽  
...  

ABSTRACT The chimpanzee is a critical animal model for studying cellular immune responses to infectious pathogens such as hepatitis B and C viruses, human immunodeficiency virus, and malaria. Several candidate vaccines and immunotherapies for these infections aim at the induction or enhancement of cellular immune responses against viral epitopes presented by common human major histocompatibility complex (MHC) alleles. To identify and characterize chimpanzee MHC class I molecules that are functionally related to human alleles, we sequenced 18 different Pan troglodytes (Patr) alleles of 14 chimpanzees, 2 of them previously unknown and 3 with only partially reported sequences. Comparative analysis of Patr binding pockets and binding assays with biotinylated peptides demonstrated a molecular homology between the binding grooves of individual Patr alleles and the common human alleles HLA-A1, -A2, -A3, and -B7. Using cytotoxic T cells isolated from the blood of hepatitis C virus (HCV)-infected chimpanzees, we then mapped the Patr restriction of these HCV peptides and demonstrated functional homology between the Patr-HLA orthologues in cytotoxicity and gamma interferon (IFN-γ) release assays. Based on these results, 21 HCV epitopes were selected to characterize the chimpanzees' cellular immune response to HCV. In each case, IFN-γ-producing T cells were detectable in the blood after but not prior to HCV infection and were specifically targeted against those HCV peptides predicted by Patr-HLA homology. This study demonstrates a close functional homology between individual Patr and HLA alleles and shows that HCV infection generates HCV peptides that are recognized by both chimpanzees and humans with Patr and HLA orthologues. These results are relevant for the design and evaluation of vaccines in chimpanzees that can now be selected according to the most frequent human MHC haplotypes.


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