The CD8 T-cell response during tolerance induction in liver transplantation

AbstractZika virus (ZIKV) has emerged as an important global health threat, with the recently acquired capacity to cause severe neurological symptoms and to persist within host tissues. We previously demonstrated that an early Asian lineage ZIKV isolate induces a highly activated CD8 T cell response specific for an immunodominant epitope in the ZIKV envelope protein in wild-type mice. Here we show that a contemporary ZIKV isolate from the Brazilian outbreak severely limits CD8 T cell immunity in mice and blocks generation of the immunodominant CD8 T cell response. This is associated with a more sustained infection that is cleared between 7- and 14-days post-infection. Mechanistically, we demonstrate that infection with the Brazilian ZIKV isolate reduces the cross-presentation capacity of dendritic cells and fails to fully activate the immunoproteasome. Thus, our study provides an isolate-specific mechanism of host immune evasion by one Brazilian ZIKV isolate, which differs from the early Asian lineage isolate and provides potential insight into viral persistence associated with recent ZIKV outbreaks.

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Nano-Microparticle Platforms in Developing Next-Generation Vaccines

Vaccines ◽

10.3390/vaccines9060606 ◽

2021 ◽

Vol 9 (6) ◽

pp. 606

Author(s):

Giuseppe Cappellano ◽

Hugo Abreu ◽

Chiara Casale ◽

Umberto Dianzani ◽

Annalisa Chiocchetti

Keyword(s):

Immune Response ◽

T Cell ◽

Cell Response ◽

Humoral Response ◽

Cd8 T Cell ◽

T Cell Response ◽

Next Generation ◽

Emerging Viruses ◽

Whole Cells ◽

Effector Functions

The first vaccines ever made were based on live-attenuated or inactivated pathogens, either whole cells or fragments. Although these vaccines required the co-administration of antigens with adjuvants to induce a strong humoral response, they could only elicit a poor CD8+ T-cell response. In contrast, next-generation nano/microparticle-based vaccines offer several advantages over traditional ones because they can induce a more potent CD8+ T-cell response and, at the same time, are ideal carriers for proteins, adjuvants, and nucleic acids. The fact that these nanocarriers can be loaded with molecules able to modulate the immune response by inducing different effector functions and regulatory activities makes them ideal tools for inverse vaccination, whose goal is to shut down the immune response in autoimmune diseases. Poly (lactic-co-glycolic acid) (PLGA) and liposomes are biocompatible materials approved by the Food and Drug Administration (FDA) for clinical use and are, therefore, suitable for nanoparticle-based vaccines. Recently, another candidate platform for innovative vaccines based on extracellular vesicles (EVs) has been shown to efficiently co-deliver antigens and adjuvants. This review will discuss the potential use of PLGA-NPs, liposomes, and EVs as carriers of peptides, adjuvants, mRNA, and DNA for the development of next-generation vaccines against endemic and emerging viruses in light of the recent COVID-19 pandemic.

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Type I Interferons Regulate the Magnitude and Functionality of Mouse Polyomavirus-Specific CD8 T Cells in a Virus Strain-Dependent Manner

Journal of Virology ◽

10.1128/jvi.00199-16 ◽

2016 ◽

Vol 90 (10) ◽

pp. 5187-5199 ◽

Cited By ~ 7

Author(s):

Qingsong Qin ◽

Shwetank ◽

Elizabeth L. Frost ◽

Saumya Maru ◽

Aron E. Lukacher

Keyword(s):

T Cells ◽

T Cell ◽

Cd8 T Cells ◽

Cell Response ◽

Cd8 T Cell ◽

T Cell Response ◽

Single Amino Acid ◽

Type I ◽

Type I Ifns ◽

Vp1 Capsid Protein

ABSTRACTMouse polyomavirus (MPyV) is a ubiquitous persistent natural mouse pathogen. A glutamic acid (E)-to-glycine (G) difference at position 91 of the VP1 capsid protein shifts the profile of tumors induced by MPyV from an epithelial to a mesenchymal cell origin. Here we asked if this tropism difference affects the MPyV-specific CD8 T cell response, which controls MPyV infection and tumorigenesis. Infection by the laboratory MPyV strain RA (VP1-91G) or a strain A2 mutant with an E-to-G substitution at VP1 residue 91 [A2(91G)] generated a markedly smaller virus-specific CD8 T cell response than that induced by A2(VP1-91E) infection. Mutant A2(91G)-infected mice showed a higher frequency of memory precursor (CD127hiKLRG1lo) CD8 T cells and a higher recall response than those of A2-infected mice. Using T cell receptor (TCR)-transgenic CD8 T cells and immunization with peptide-pulsed dendritic cells, we found that early bystander inflammation associated with A2 infection contributed to recruitment of the larger MPyV-specific CD8 T cell response. Beta interferon (IFN-β) transcripts were induced early during A2 or A2(91G) infections. IFN-β inhibited replication of A2 and A2(91G)in vitro. Using mice lacking IFN-αβ receptors (IFNAR−/−), we showed that type I IFNs played a role in controlling MPyV replicationin vivobut differentially affected the magnitude and functionality of virus-specific CD8 T cells recruited by A2 and A2(91G) viral infections. These data indicate that type I IFNs are involved in protection against MPyV infection and that their effect on the antiviral CD8 T cell response depends on capsid-mediated tropism properties of the MPyV strain.IMPORTANCEIsolates of the human polyomavirus JC virus from patients with the frequently fatal demyelinating brain disease progressive multifocal leukoencephalopathy (PML) carry single amino acid substitutions in the domain of the VP1 capsid protein that binds the sialic acid moiety of glycoprotein/glycolipid receptors on host cells. These VP1 mutations may alter neural cell tropism or enable escape from neutralizing antibodies. Changes in host cell tropism can affect recruitment of virus-specific CD8 T cells. Using mouse polyomavirus, we demonstrate that a single amino acid difference in VP1 known to shift viral tropism profoundly affects the quantity and quality of the anti-polyomavirus CD8 T cell response and its differentiation into memory cells. These findings raise the possibility that CD8 T cell responses to infections by human polyomaviruses may be influenced by VP1 mutations involving domains that engage host cell receptors.

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Cytotoxic T-Cell Response Following Mouse Liver Transplantation Is Independent of the Initial Site of T-Cell Priming

Transplantation Proceedings ◽

10.1016/j.transproceed.2006.10.157 ◽

2006 ◽

Vol 38 (10) ◽

pp. 3241-3243 ◽

Cited By ~ 3

Author(s):

I. Klein ◽

H.-J. Gassel ◽

I.N. Crispe

Keyword(s):

Liver Transplantation ◽

T Cell ◽

Cell Response ◽

Mouse Liver ◽

T Cell Response ◽

Cytotoxic T Cell ◽

T Cell Priming

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