scholarly journals Polyclonal epitope cartography reveals the temporal dynamics and diversity of human antibody responses to H5N1 vaccination

2020 ◽  
Author(s):  
Julianna Han ◽  
Aaron J. Schmitz ◽  
Sara T. Richey ◽  
Ya-Nan Dai ◽  
Hannah L. Turner ◽  
...  
Keyword(s):  
Immune Responses ◽  
Influenza A ◽  
Epitope Mapping ◽  
Temporal Dynamics ◽  
De Novo ◽  
Human Antibody ◽  
Post Vaccination ◽  
Antigenic Sites ◽  
Universal Influenza Vaccine ◽  
Novel Influenza A

SUMMARYNovel influenza A virus (IAV) strains elicit recall immune responses to conserved epitopes, making them favorable antigenic choices for universal influenza virus vaccines. Evaluating these immunogens requires a thorough understanding of the antigenic sites targeted by the polyclonal antibody (pAb) response, which single particle electron microscopy (EM) can sensitively detect. Here, we employed EM polyclonal epitope mapping (EMPEM) to extensively characterize the pAb response to hemagglutinin (HA) after H5N1 immunization in humans. Cross-reactive pAbs originating from memory B cells immediately bound the stem of HA and persisted for over a year post vaccination. In contrast, de novo pAb responses to multiple sites on the head of HA, which targeted previously determined key neutralizing sites on H5 HA, expanded after the second immunization and waned quickly. Thus, EMPEM provides a robust tool for comprehensively tracking the specificity and durability of immune responses elicited by novel universal influenza vaccine candidates.

scholarly journals Polyclonal epitope mapping reveals temporal dynamics and diversity of human antibody responses to H5N1 vaccination

Cell Reports ◽  
2021 ◽  
Vol 34 (4) ◽  
pp. 108682
Author(s):  
Julianna Han ◽  
Aaron J. Schmitz ◽  
Sara T. Richey ◽  
Ya-Nan Dai ◽  
Hannah L. Turner ◽  
...  
Keyword(s):  
Epitope Mapping ◽  
Temporal Dynamics ◽  
Antibody Responses ◽  
Human Antibody

scholarly journals Baseline Levels of Influenza-Specific B Cells and T Cell Responses Modulate Human Immune Responses to Swine Variant Influenza A/H3N2 Vaccine

Vaccines ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 126
Author(s):  
Lilin Lai ◽  
Nadine Rouphael ◽  
Yongxian Xu ◽  
Amy C. Sherman ◽  
Srilatha Edupuganti ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
Influenza A ◽  
Vaccine Dose ◽  
T Cell Responses ◽  
Post Vaccination ◽  
Cell Responses ◽  
Cellular Immune Responses ◽  
Cellular Immune

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.

scholarly journals Key Determinants of Cell-Mediated Immune Responses: A Randomized Trial of High Dose Vs. Standard Dose Split-Virus Influenza Vaccine in Older Adults

2021 ◽  
Vol 2 ◽  
Author(s):  
Chris P. Verschoor ◽  
Laura Haynes ◽  
Graham Pawelec ◽  
Mark Loeb ◽  
Melissa K. Andrew ◽  
...  
Keyword(s):  
Older Adults ◽  
Immune Responses ◽  
Influenza Vaccine ◽  
Influenza A ◽  
Standard Dose ◽  
Serum Antibody ◽  
High Dose ◽  
Post Vaccination ◽  
Antibody Titers ◽  
Virus Influenza

Background: Efforts to improve influenza vaccine effectiveness in older adults have resulted in some successes, such as the introduction of high-dose split-virus influenza vaccine (HD-SVV), yet studies of cell-mediated immune responses to these vaccines remain limited. We have shown that granzyme B (GrB) activity in influenza A/H3N2 challenged peripheral blood mononuclear cells (PBMC) correlates with protection against influenza following standard dose vaccination (SD-SVV) in older adults. Further, the interferon-γ (IFNγ) to interleukin-10 (IL-10) ratio can be a correlate of protection.Methods: In a double-blind trial (ClinicalTrials.gov NCT02297542) older adults (≥65 years, n = 582) were randomized to receive SD-SVV or HD-SVV (Fluzone®) from 2014/15 to 2017/18. Young adults (20–40 years, n = 79) received SD-SVV. At 0, 4, 10, and 20 weeks post-vaccination, serum antibody titers, IFNγ, IL-10, and inducible GrB (iGrB) were measured in ex vivo influenza-challenged PBMC. iGrB is defined as the fold change in GrB activity from baseline levels (bGrB) in circulating T cells. Responses of older adults were compared to younger controls, and in older adults, we analyzed effects of age, sex, cytomegalovirus (CMV) serostatus, frailty, and vaccine dose.Results: Prior to vaccination, younger compared to older adults produced significantly higher IFNγ, IL-10, and iGrB levels. Relative to SD-SVV recipients, older HD-SVV recipients exhibited significantly lower IFNγ:IL-10 ratios at 4 weeks post-vaccination. In contrast, IFNγ and iGrB levels were higher in younger SD vs. older SD or HD recipients; only the HD group showed a significant IFNγ response to vaccination compared to the SD groups; all three groups showed a significant iGrB response to vaccination. In a regression analysis, frailty was associated with lower IFNγ levels, whereas female sex and HD-SVV with higher IL-10 levels. Age and SD-SVV were associated with lower iGrB levels. The effect of prior season influenza vaccination was decreased iGrB levels, and increased IFNγ and IL-10 levels, which correlated with influenza A/H3N2 hemagglutination inhibition antibody titers.Conclusion: Overall, HD-SVV amplified the IL-10 response consistent with enhanced antibody responses, with little effect on the iGrB response relative to SD-SVV in either younger or older adults. These results suggest that enhanced protection with HD-SVV is largely antibody-mediated.Clinical Trial Registration: ClinicalTrials.gov (NCT02297542).

Design, synthesis and primary immunologic evaluation of M2e-CRM197 conjugate as a universal influenza vaccine candidate

2020 ◽  
Vol 21 ◽  
Author(s):  
Lu Xu ◽  
Chun Zhang ◽  
Jing Zhang ◽  
Rong Yu ◽  
Zhiguo Su
Keyword(s):  
Immune Responses ◽  
Influenza Vaccine ◽  
Influenza A Virus ◽  
Influenza A ◽  
Vaccine Development ◽  
Acute Infection ◽  
Acid Hydrazide ◽  
Influenza Viruses ◽  
Carrier Protein ◽  
Universal Influenza Vaccine

Background: Influenza is a contagious respiratory illness caused by acute infection of influenza viruses, among which influenza A virus causes epidemic seasonal infection nearly every year. Along with unpredictability of evolving influenza A virus and time-consuming vaccine development cycles, novel universal influenza vaccine designed to induce broadly cross-reactive immune responses against frequently mutant influenza A virus strains are greatly urgent. Objective: The aim of this study was to synthesize a novel vaccine through the dual-site specific conjugation of the constant epitope of 23 amino acids (M2e) of influenza A virus with highly immunogenic carrier protein of cross-reacting material (CRM197) under denaturation, and evaluate its primary immunogenicity in mice. Methods: The antigen (M2e) and the carrier protein (CRM197) were linked with different type of hetero-functionalized linkers, α-maleimide-ε-hydrazide polyethylene glycol 2k (MAL-PEG-HZ) and N-β-maleimidopropionic acid hydrazide (BMPH) separately. The immunogenicity of the M2e-CRM197 conjugates with different type of linkers was evaluated in mice, and the M2e-specific total IgG and IgG-isotypes were determined by ELSIA. Results: Immunogenicity study revealed that anti-M2e antibody could be induced by the conjugate products, M2e-PEGCRM197 and M2e-BMPH-CRM197, were approximately 30 and 90-fold higher than that of M2e group. In addition, the antiM2e antibody level induced by M2e-PEG-CRM197 conjugate was three times higher than that of M2e-BMPH-CRM197 conjugate, and the former could simultaneously activate both cellar and humoral immune responses. Conclusions: The M2e-CRM197 conjugated vaccines we synthesized in this study are highly immunogenic compared with M2e alone. Besides, evidences were presented here indicated that the hydrophilic, non-immunogenic and biocompatible chain of the cross-linker might be a better choice for development of conjugate vaccine.

scholarly journals Construction, characterization, and immunization of nanoparticles that display a diverse array of influenza HA trimers

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247963 ◽  
Author(s):  
Alexander A. Cohen ◽  
Zhi Yang ◽  
Priyanthi N. P. Gnanapragasam ◽  
Susan Ou ◽  
Kim-Marie A. Dam ◽  
...  
Keyword(s):  
Immune Responses ◽  
Influenza Vaccine ◽  
Neutralizing Antibodies ◽  
Influenza A ◽  
Electron Tomography ◽  
Covalent Attachment ◽  
Humoral Immune ◽  
Group 2 ◽  
Multiple Strains ◽  
Universal Influenza Vaccine

Current influenza vaccines do not elicit broadly protective immune responses against multiple strains. New strategies to focus the humoral immune response to conserved regions on influenza antigens are therefore required for recognition by broadly neutralizing antibodies. It has been suggested that B-cells with receptors that recognize conserved epitopes would be preferentially stimulated through avidity effects by mosaic particles presenting multiple forms of a variable antigen. We adapted SpyCatcher-based platforms, AP205 virus-like particles (VLPs) and mi3 nanoparticles (NPs), to covalently co-display SpyTagged hemagglutinin (HA) trimers from group 1 and group 2 influenza A strains. Here we show successful homotypic and heterotypic conjugation of up to 8 different HA trimers to both VLPs and NPs. We characterized the HA-VLPs and HA-NPs by cryo-electron tomography to derive the average number of conjugated HAs and their separation distances on particles, and compared immunizations of mosaic and homotypic particles in wild-type mice. Both types of HA particles elicited strong antibody responses, but the mosaic particles did not consistently elicit broader immune responses than mixtures of homotypic particles. We conclude that covalent attachment of HAs from currently-circulating influenza strains represents a viable alternative to current annual influenza vaccine strategies, but in the absence of further modifications, is unlikely to represent a method for making a universal influenza vaccine.

scholarly journals Epitope mapping of the 2009 pandemic and the A/Brisbane/59/2007 seasonal (H1N1) influenza virus haemagglutinins using mAbs and escape mutants

2014 ◽  
Vol 95 (11) ◽  
pp. 2377-2389 ◽  
Author(s):  
Miguel Retamal ◽  
Yacine Abed ◽  
Jacques Corbeil ◽  
Guy Boivin
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Epitope Mapping ◽  
Antigenic Site ◽  
H1n1 Influenza ◽  
Hek293 Cells ◽  
Antigenic Sites ◽  
Influenza A H1n1 ◽  
Biological Tool ◽  
Escape Mutants

mAbs constitute an important biological tool for influenza virus haemagglutinin (HA) epitope mapping through the generation of escape mutants, which could provide insights into immune evasion mechanisms and may benefit the future development of vaccines. Several influenza A (H1N1) pandemic 2009 (pdm09) HA escape mutants have been recently described. However, the HA antigenic sites of the previous seasonal A/Brisbane/59/2007 (H1N1) (Bris07) virus remain poorly documented. Here, we produced mAbs against pdm09 and Bris07 HA proteins expressed in human HEK293 cells. Escape mutants were generated using mAbs that exhibited HA inhibition and neutralizing activities. The resulting epitope mapping of the pdm09 HA protein revealed 11 escape mutations including three that were previously described (G172E, N173D and K256E) and eight novel ones (T89R, F128L, G157E, K180E, A212E, R269K, N311T and G478E). Among the six HA mutations that were part of predicted antigenic sites (Ca1, Ca2, Cb, Sa or Sb), three (G172E, N173D and K180E) were within the Sa site. Eight escape mutations (H54N, N55D, N55K, L60H, N203D, A231T, V314I and K464E) were obtained for Bris07 HA, and all but one (N203D, Sb site) were outside the predicted antigenic sites. Our results suggest that the Sa antigenic site is immunodominant in pdm09 HA, whereas the N203D mutation (Sb site), present in three different Bris07 escape mutants, appears as the immunodominant epitope in that strain. The fact that some mutations were not part of predicted antigenic sites reinforces the necessity of further characterizing the HA of additional H1N1 strains.

scholarly journals Construction, characterization, and immunization of nanoparticles that display a diverse array of influenza HA trimers

2020 ◽  
Author(s):  
Alexander A. Cohen ◽  
Zhi Yang ◽  
Priyanthi NP Gnanapragasam ◽  
Susan Ou ◽  
Kim-Marie A. Dam ◽  
...  
Keyword(s):  
Immune Responses ◽  
Influenza Vaccine ◽  
Neutralizing Antibodies ◽  
Influenza A ◽  
Electron Tomography ◽  
Covalent Attachment ◽  
Humoral Immune ◽  
Group 2 ◽  
Multiple Strains ◽  
Universal Influenza Vaccine

AbstractCurrent influenza vaccines do not elicit broadly protective immune responses against multiple strains. New strategies to focus the humoral immune response to conserved regions on influenza antigens are therefore required for recognition by broadly neutralizing antibodies. It has been suggested that B-cells with receptors that recognize conserved epitopes would be preferentially stimulated through avidity effects by mosaic particles presenting multiple forms of a variable antigen. We adapted SpyCatcher-based platforms, AP205 virus-like particles (VLPs) and mi3 nanoparticles (NPs), to covalently co-display SpyTagged hemagglutinin (HA) trimers from group 1 and group 2 influenza A strains. Here we show successful homotypic and heterotypic conjugation of up to 8 different HA trimers to both VLPs and NPs. We characterized the HA-VLPs and HA-NPs by cryo-electron tomography to derive the average number of conjugated HAs and their separation distances on particles, and compared immunizations of mosaic and homotypic particles in wild-type mice. Both types of HA particles elicited strong antibody responses, but the mosaic particles did not consistently elicit broader immune responses than mixtures of homotypic particles. We conclude that covalent attachment of HAs from currently-circulating influenza strains represents a viable alternative to current annual influenza vaccine strategies, but in the absence of further modifications, is unlikely to represent a method for making a universal influenza vaccine.

scholarly journals The Effect of Preexisting Immunity on Virus Detection and Immune Responses in a Phase II, Randomized Trial of a Russian-Backbone, Live, Attenuated Influenza Vaccine in Bangladeshi Children

2018 ◽  
Vol 69 (5) ◽  
pp. 786-794 ◽  
Author(s):  
Elizabeth B Brickley ◽  
Peter F Wright ◽  
Alexey Khalenkov ◽  
Kathleen M Neuzil ◽  
Justin R Ortiz ◽  
...  
Keyword(s):  
Immune Responses ◽  
Influenza Vaccine ◽  
Phase Ii ◽  
Influenza A ◽  
Virus Detection ◽  
Strain Differences ◽  
Potential Effect ◽  
Post Vaccination ◽  
Live Attenuated Influenza Vaccine ◽  
Bidirectional Association

Abstract Background In a 2012 Phase II clinical trial, 300 Bangladeshi children aged 24 to 59 months with no prior influenza vaccine exposure were randomized to receive a single intranasally-administered dose of either trivalent, Russian-backbone, live, attenuated influenza vaccine (LAIV) or placebo. Protocol-defined analyses, presented in the companion manuscript, demonstrate decreased viral detection and immunogenicity for A/H1N1pdm09, relative to the A/H3N2 and B strains. This post hoc analysis of the trial data aims to investigate the LAIV strain differences by testing the hypothesis that preexisting humoral and mucosal immunity may influence viral recovery and immune responses after LAIV receipt. Methods We used logistic regressions to evaluate the relations between markers of preexisting immunity (ie, hemagglutination inhibition [HAI], microneutralization, and immunoglobulin G and immunoglobulin A (both serum and mucosal antibodies) and LAIV viral recovery in the week post-vaccination. We then tested for potential effect modification by baseline HAI titers (ie, <10 versus ≥10) and week 1 viral recovery on the LAIV-induced serum and mucosal immune responses, measured between days 0 and 21 post-vaccination. Results Higher levels of preexisting immunity to influenza A/H3N2 and B were strongly associated with strain-specific prevention of viral shedding upon LAIV receipt. While evidence of LAIV immunogenicity was observed for all 3 strains, the magnitudes of immune responses were most pronounced in children with no evidence of preexisting HAI and in those with detectable virus. Conclusions The results provide evidence for a bidirectional association between viral replication and immunity, and underscore the importance of accounting for preexisting immunity when evaluating virologic and immunologic responses to LAIVs. Clinical Trials Registration NCT01625689.

scholarly journals Sex disparities in influenza: a multiscale network analysis

2021 ◽  
Author(s):  
Chang Wang ◽  
Lauren P Lashua ◽  
Charlise E Carter ◽  
Scott K Johnson ◽  
Minghui Wang ◽  
...  
Keyword(s):  
Sex Differences ◽  
Immune Responses ◽  
Influenza A ◽  
Temporal Dynamics ◽  
Inflammatory Responses ◽  
Influenza Virus Infection ◽  
Metabolic Reprogramming ◽  
Unfolded Protein ◽  
The Unfolded Protein Response ◽  
Protein Response

Sex differences in the pathogenesis of infectious diseases due to differential immune responses between females and males have been well documented for multiple pathogens. However, the molecular mechanism underlying the observed sex differences in influenza virus infection remains poorly understood. In this study, we used a network-based approach to characterize the blood transcriptome collected over the course of infection with influenza A virus from female and male ferrets to dissect sex-biased gene expression. We identified significant differences in the temporal dynamics and regulation of immune responses between females and males. Our results elucidate sex-differentiated pathways involved in the unfolded protein response (UPR), lipid metabolism, and inflammatory responses, including a female-biased IRE1/XBP1 activation and male-biased crosstalk between metabolic reprogramming and IL-1 and AP-1 pathways. Overall, our study provides molecular insights into sex differences in transcriptional regulation of immune responses and contributes to a better understanding of sex bias in influenza pathogenesis.

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