scholarly journals Systems Immunology Analyses Following Porcine Respiratory and Reproductive Syndrome Virus Infection and Vaccination

2021 ◽  
Vol 12 ◽  
Author(s):  
Loïc Vivien Bocard ◽  
Andrew Robert Kick ◽  
Corinne Hug ◽  
Heidi Erika Lisa Lischer ◽  
Tobias Käser ◽  
...  

This study was initiated to better understand the nature of innate immune responses and the relatively weak and delayed immune response against porcine reproductive and respiratory syndrome virus (PRRSV). Following modified live virus (MLV) vaccination or infection with two PRRSV-2 strains, we analyzed the transcriptome of peripheral blood mononuclear cells collected before and at three and seven days after vaccination or infection. We used blood transcriptional modules (BTMs)-based gene set enrichment analyses. BTMs related to innate immune processes were upregulated by PRRSV-2 strains but downregulated by MLV. In contrast, BTMs related to adaptive immune responses, in particular T cells and cell cycle, were downregulated by PRRSV-2 but upregulated by MLV. In addition, we found differences between the PRRSV strains. Only the more virulent strain induced a strong platelet activation, dendritic cell activation, interferon type I and plasma cell responses. We also calculated the correlations of BTM with the neutralizing antibody and the T-cell responses. Early downregulation (day 0–3) of dendritic cell and B-cell BTM correlated to both CD4 and CD8 T-cell responses. Furthermore, a late (day 3–7) upregulation of interferon type I modules strongly correlated to helper and regulatory T-cell responses, while inflammatory BTM upregulation correlated more to CD8 T-cell responses. BTM related to T cells had positive correlations at three days but negative associations at seven days post-infection. Taken together, this work contributes to resolve the complexity of the innate and adaptive immune responses against PRRSV and indicates a fundamentally different immune response to the less immunogenic MLV compared to field strains which induced robust adaptive immune responses. The identified correlates of T-cell responses will facilitate a rational approach to improve the immunogenicity of MLV.

2020 ◽  
Author(s):  
Stine SF Nielsen ◽  
Line K Vibholm ◽  
Ida Monrad ◽  
Rikke Olesen ◽  
Giacomo S Frattari ◽  
...  

AbstractThe SARS-CoV-2 pandemic currently prevails worldwide. To understand the immunological signature of SARS-CoV-2 infections and aid the search for treatments and vaccines, comprehensive characterization of adaptive immune responses towards SARS-CoV-2 is needed. We investigated the breadth and potency of antibody-, and T-cell immune responses, in 203 recovered SARS-CoV-2 infected patients who presented with asymptomatic to severe infections. We report very broad serological profiles with cross-reactivity to other human coronaviruses. Further, >99% had SARS-CoV-2 epitope specific antibodies, with SARS-CoV-2 neutralization and spike-ACE2 receptor interaction blocking observed in 95% of individuals. A significant positive correlation between spike-ACE2 blocking antibody titers and neutralization potency was observed. SARS-CoV-2 specific CD8+ T-cell responses were clear and quantifiable in 90% of HLA-A2+ individuals. The viral surface spike protein was identified as the dominant target for both neutralizing antibodies and CD8+ T cell responses. Overall, the majority of patients had robust adaptive immune responses, regardless of disease severity.Author summarySARS-CoV-2 can cause severe and deadly infections. However, the immunological understanding of this viral infection is limited. Currently, several vaccines are being developed to help limit transmission and prevent the current pandemic. However, basic understanding of the adaptive immune response developed during SARS-CoV-2 infections is needed to inform further vaccine development and to understand the protective properties of the developed immune response. We investigated, the adaptive immune response developed during SARS-CoV-2 infections in recovered patients experiencing a full spectrum of disease severity, from asymptomatic infections to severe cases requiring hospitalization. We used a novel multiplex serological platform, cell-based neutralization assays and dextramer flow cytometry assays to characterize a broad and robust humoral and cellular immune response towards SARS-CoV-2. We found that the vast majority of recovered individuals have clear detectable and functional SARS-CoV-2 spike specific adaptive immune responses, despite diverse disease severities. The detection of both a humoral and cellular functional spike specific immune response in the vast majority of the individuals, irrespective of asymptomatic manifestations, supports vaccine designs currently underway, and encourages further exploration of whether primary infections provide protection to reinfection.


npj Vaccines ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Mauro Di Pilato ◽  
Miguel Palomino-Segura ◽  
Ernesto Mejías-Pérez ◽  
Carmen E. Gómez ◽  
Andrea Rubio-Ponce ◽  
...  

AbstractNeutrophils are innate immune cells involved in the elimination of pathogens and can also induce adaptive immune responses. Nα and Nβ neutrophils have been described with distinct in vitro capacity to generate antigen-specific CD8 T-cell responses. However, how these cell types exert their role in vivo and how manipulation of Nβ/Nα ratio influences vaccine-mediated immune responses are not known. In this study, we find that these neutrophil subtypes show distinct migratory and motility patterns and different ability to interact with CD8 T cells in the spleen following vaccinia virus (VACV) infection. Moreover, after analysis of adhesion, inflammatory, and migration markers, we observe that Nβ neutrophils overexpress the α4β1 integrin compared to Nα. Finally, by inhibiting α4β1 integrin, we increase the Nβ/Nα ratio and enhance CD8 T-cell responses to HIV VACV-delivered antigens. These findings provide significant advancements in the comprehension of neutrophil-based control of adaptive immune system and their relevance in vaccine design.


2021 ◽  
Author(s):  
Alison Tarke ◽  
John Sidney ◽  
Nils Methot ◽  
Yun Zhang ◽  
Jennifer M Dan ◽  
...  

The emergence of SARS-CoV-2 variants highlighted the need to better understand adaptive immune responses to this virus. It is important to address whether also CD4+ and CD8+ T cell responses are affected, because of the role they play in disease resolution and modulation of COVID-19 disease severity. Here we performed a comprehensive analysis of SARS-CoV-2-specific CD4+ and CD8+ T cell responses from COVID-19 convalescent subjects recognizing the ancestral strain, compared to variant lineages B.1.1.7, B.1.351, P.1, and CAL.20C as well as recipients of the Moderna (mRNA-1273) or Pfizer/BioNTech (BNT162b2) COVID-19 vaccines. Similarly, we demonstrate that the sequences of the vast majority of SARS-CoV-2 T cell epitopes are not affected by the mutations found in the variants analyzed. Overall, the results demonstrate that CD4+ and CD8+ T cell responses in convalescent COVID-19 subjects or COVID-19 mRNA vaccinees are not substantially affected by mutations found in the SARS-CoV-2 variants.


2021 ◽  
Vol 17 (3) ◽  
pp. e1009363
Author(s):  
Erica Andersen-Nissen ◽  
Andrew Fiore-Gartland ◽  
Lamar Ballweber Fleming ◽  
Lindsay N. Carpp ◽  
Anneta F. Naidoo ◽  
...  

The pox-protein regimen tested in the RV144 trial is the only vaccine strategy demonstrated to prevent HIV-1 infection. Subsequent analyses identified antibody and cellular immune responses as correlates of risk (CoRs) for HIV infection. Early predictors of these CoRs could provide insight into vaccine-induced protection and guide efforts to enhance vaccine efficacy. Using specimens from a phase 1b trial of the RV144 regimen in HIV-1-uninfected South Africans (HVTN 097), we profiled innate responses to the first ALVAC-HIV immunization. PBMC transcriptional responses peaked 1 day post-vaccination. Type I and II interferon signaling pathways were activated, as were innate pathways critical for adaptive immune priming. We then identified two innate immune transcriptional signatures strongly associated with adaptive immune CoR after completion of the 4-dose regimen. Day 1 signatures were positively associated with antibody-dependent cellular cytotoxicity and phagocytosis activity at Month 6.5. Conversely, a signature present on Days 3 and 7 was inversely associated with Env-specific CD4+ T cell responses at Months 6.5 and 12; rapid resolution of this signature was associated with higher Env-specific CD4+ T-cell responses. These are the first-reported early immune biomarkers of vaccine-induced responses associated with HIV-1 acquisition risk in humans and suggest hypotheses to improve HIV-1 vaccine regimens.


PLoS ONE ◽  
2012 ◽  
Vol 7 (7) ◽  
pp. e40865 ◽  
Author(s):  
Selina Jessica Keppler ◽  
Kerstin Rosenits ◽  
Tamara Koegl ◽  
Smiljka Vucikuja ◽  
Peter Aichele

2011 ◽  
Vol 209 (1) ◽  
pp. 157-171 ◽  
Author(s):  
De Yang ◽  
Yuri V. Postnikov ◽  
Yana Li ◽  
Poonam Tewary ◽  
Gonzalo de la Rosa ◽  
...  

Alarmins are endogenous mediators capable of promoting the recruitment and activation of antigen-presenting cells (APCs), including dendritic cells (DCs), that can potentially alert host defense against danger signals. However, the relevance of alarmins to the induction of adaptive immune responses remains to be demonstrated. In this study, we report the identification of HMGN1 (high-mobility group nucleosome-binding protein 1) as a novel alarmin and demonstrate that it contributes to the induction of antigen-specific immune responses. HMGN1 induced DC maturation via TLR4 (Toll-like receptor 4), recruitment of APCs at sites of injection, and activation of NF-κB and multiple mitogen-activated protein kinases in DCs. HMGN1 promoted antigen-specific immune response upon co-administration with antigens, and Hmgn1−/− mice developed greatly reduced antigen-specific antibody and T cell responses when immunized with antigens in the presence of lipopolysaccharide (LPS). The impaired ability of Hmgn1−/− mice to mount antigen-specific immune responses was accompanied by both deficient DC recruitment at sites of immunization and reduced production of inflammatory cytokines. Bone marrow chimera experiments revealed that HMGN1 derived from nonleukocytes was critical for the induction of antigen-specific antibody and T cell responses. Thus, extracellular HMGN1 acts as a novel alarmin critical for LPS-induced development of innate and adaptive immune responses.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 3-3
Author(s):  
Ning Li ◽  
Thais Bertolini ◽  
Roland W Herzog

Adeno-associated viral (AAV) vectors are currently evaluated in multiple Phase III clinical trial for the treatment of hemophilia and neuromuscular disorders. A major concern is the potential for immune responses. Viral vectors are initially sensed by the innate immune system, which shapes subsequent adaptive immune responses. Particularly, toll-like receptors (TLRs) have been reported as major sensors of pathogens during innate immune response. TLRs recognize pathogen-associated molecular patterns (PAMPs). Our previous studies found that cross-priming of AAV capsid-specific CD8+ T cells depended on TLR9-MyD88 pathway. TLR9 is an endosomal DNA receptor that responds most potently to unmethylated CpG motifs as found in bacterial and viral DNA. Similarly, others documented TLR9-dependent CD8+ T cell responses against non-secreted transgene products such as LacZ and hemagglutinin upon muscle-directed AAV gene transfer. Similarly, we published that CD8+ T cell responses to a secreted ovalbumin (ova) transgene product were substantially reduced (although not entirely eliminated) upon muscle gene transfer in TLR9-deficient mice [J Innate Immun. 7:302-14]. For those studies, we had used a self-complementary scAAV genomes, which we found to more strongly activate TLR9 than conventional single-stranded ssAAV vectors. Here, we performed intramuscular injections of 3 doses of ssAAV1-CMV-ova vector (2X1010, 2X1011 and1X1012 vg) in wild-type (WT), TLR9-/-, or MYD88-/- C57BL/6 mice. Using MHC tetramer (H2-Kb -SIINFEKL), ova-specific CD8+ T cell frequencies were monitored in peripheral blood for up to 6 weeks. As expected from prior studies, TLR9-/- mice showed a substantially reduced response (1.2% tetramer+ of CD8) at the low dose when compared to WT (12% tetramer+ of CD8) animals (p<0.0001, n=5/group). To our surprise, CD8+ T cell responses were similar in TLR9-/- and WT mice at the 2 higher doses. TLR9-/- mice displayed 16% and 3.3% tetramer+ of CD8 frequencies at the median and the high doses, respectively; which was comparable to WT mice, where 15% and 4.8% tetramer+ of CD8 frequencies were observed (n=5/group). Therefore, sensing of the AAV genome by TLR9 is more critical for the CD8+ T cell response to the secreted transgene product at lower vector doses (possibly related to the lower levels of transgene expression). Interestingly, transgene product-specific CD8+ T cell responses were much reduced in MyD88-/- mice, in which 0.2% and 1.7% tetramer+ of CD8 frequencies were found for low and median doses. Therefore, an alternative signaling pathway that includes the MyD88 adaptor molecule likely exists that is more critical than TLR9 above a certain level of expression. The reduced strength of the CD8+ T cell response seen at the highest vector dose compared to the medium dose may be explained by a transient increase in FoxP3+ Treg and in PD-1+ T cells that we observed 1 week after gene transfer and that was significantly greater at the highest vector dose. In related experiments, we performed intramuscular gene transfer using a ssAAV1-EF1a-FIX vector in hemophilia B mice (C3H/HeJ F9-/-, 1x1011 vg/mouse). Here, we used either a vector with native sequences or with an expression cassette that was entirely devoid of CpG motifs (and there stimulates TLR9 less effectively). CpG depletion did not have substantial effects on antibody formation against human FIX or the viral capsid. However, CD8+ T cell infiltrates in skeletal muscle were markedly reduced but not entirely eliminated when tissue sections were examined 1 month after gene transfer. In conclusion, TLR9 signaling is one important factor in the activation of transgene product-specific CD8+ T cells in AAV gene transfer, but other pathways exist that may be more critical depending on vector dose or levels of expression. Disclosures Herzog: Takeda Pharmaceuticals: Patents & Royalties.


2020 ◽  
Vol 95 (2) ◽  
pp. e01155-20
Author(s):  
Carmen Elena Gómez ◽  
Beatriz Perdiguero ◽  
Michela Falqui ◽  
María Q. Marín ◽  
Martina Bécares ◽  
...  

ABSTRACTInduction of the endogenous innate immune system by interferon (IFN) triggers the expression of many proteins that serve like alarm bells in the body, activating an immune response. After a viral infection, one of the genes activated by IFN induction is the IFN-stimulated gene 15 (ISG15), which encodes a ubiquitin-like protein that undergoes a reversible posttranslational modification (ISGylation). ISG15 protein can also act unconjugated, intracellularly and secreted, acting as a cytokine. Although ISG15 has an essential role in host defense responses to microbial infection, its role as an immunomodulator in the vaccine field remains to be defined. In this investigation, we showed that ISG15 exerts an immunomodulatory role in human immunodeficiency virus (HIV) vaccines. In mice, after priming with a DNA-ISG15 vector mixed with a DNA expressing HIV-1 gp120 (DNA-gp120), followed by a booster with a modified vaccinia virus Ankara (MVA) vector expressing HIV-1 antigens, both wild-type ISG15-conjugated (ISG15-wt) and mutant unconjugated (ISG15-mut) proteins act as immune adjuvants by increasing the magnitude and quality of HIV-1-specific CD8 T cells, with ISG15-wt providing better immunostimulatory activity than ISG15-mut. The HIV-1 Env-specific CD8 T cell responses showed a predominant T effector memory (TEM) phenotype in all groups. Moreover, the amount of DNA-gp120 used to immunize mice could be reduced 5-fold after mixing with DNA-ISG15 without affecting the potency and the quality of the HIV-1 Env-specific immune responses. Our study clearly highlights the potential use of the IFN-induced ISG15 protein as immune adjuvant to enhance immune responses to HIV antigens, suggesting that this molecule might be exploitable for prophylactic and therapeutic vaccine approaches against pathogens.IMPORTANCE Our study described the potential role of ISG15 as an immunomodulatory molecule in the optimization of HIV/AIDS vaccine candidates. Using a DNA prime–MVA boost immunization protocol, our results indicated an increase in the potency and the quality of the HIV-1 Env-specific CD8 T cell response. These results highlight the adjuvant potency of ISG15 to elicit improved viral antigen presentation to the immune system, resulting in an enhanced HIV-1 vaccine immune response. The DNA-ISG15 vector could find applicability in the vaccine field in combination with other nucleic acid-based vector vaccines.


Blood ◽  
2003 ◽  
Vol 101 (9) ◽  
pp. 3520-3526 ◽  
Author(s):  
Jean-François Fonteneau ◽  
Michel Gilliet ◽  
Marie Larsson ◽  
Ida Dasilva ◽  
Christian Münz ◽  
...  

Plasmacytoid dendritic cells (pDCs) contribute to innate antiviral immune responses by producing type I interferons (IFNs) upon exposure to enveloped viruses. However, their role in adaptive immune responses, such as the initiation of antiviral T-cell responses, is not known. In this study, we examined interactions between blood pDCs and influenza virus with special attention to the capacity of pDCs to activate influenza-specific T cells. pDCs were compared with CD11c+ DCs, the most potent antigen-presenting cells (APCs), for their capacity to activate T-cell responses. We found that like CD11c+ DCs, pDCs mature following exposure to influenza virus, express CCR7, and produce proinflammatory chemokines, but differ in that they produce type I IFN and are resistant to the cytopathic effect of the infection. After influenza virus exposure, both DC types exhibited an equivalent efficiency to expand anti–influenza virus cytotoxic T lymphocytes (CTLs) and T helper 1 (TH1) CD4+ T cells. Our results pinpoint a new role of pDCs in the induction of antiviral T-cell responses and suggest that these DCs play a prominent role in the adaptive immune response against viruses.


Science ◽  
2019 ◽  
Vol 364 (6446) ◽  
pp. 1179-1184 ◽  
Author(s):  
Eduard Ansaldo ◽  
Leianna C. Slayden ◽  
Krystal L. Ching ◽  
Meghan A. Koch ◽  
Natalie K. Wolf ◽  
...  

Intestinal adaptive immune responses influence host health, yet only a few intestinal bacteria species that induce cognate adaptive immune responses during homeostasis have been identified. Here, we show that Akkermansia muciniphila, an intestinal bacterium associated with systemic effects on host metabolism and PD-1 checkpoint immunotherapy, induces immunoglobulin G1 (IgG1) antibodies and antigen-specific T cell responses in mice. Unlike previously characterized mucosal responses, T cell responses to A. muciniphila are limited to T follicular helper cells in a gnotobiotic setting, without appreciable induction of other T helper fates or migration to the lamina propria. However, A. muciniphila–specific responses are context dependent and adopt other fates in conventional mice. These findings suggest that, during homeostasis, contextual signals influence T cell responses to the microbiota and modulate host immune function.


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