scholarly journals Wnt5A supports antigen cross-presentation and CD8 T cell activation.

2022 ◽  
Author(s):  
Tresa Rani Sarraf ◽  
Malini Sen
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Response ◽  
Antigen Processing ◽  
Cell Activation ◽  
Cd8 T Cell ◽  
T Cell Response ◽  
Mouse Bone Marrow ◽  
Recall Response ◽  
Cross Presentation

Antigen processing, cross-presentation, and antigen-specific CD8 T cell response form part and parcel of T cell-mediated immunity. Yet, lacunae remain in our understanding of antigen processing/presentation and CD8 T cell response. Given the association of Wnt5A signaling with immune homeostasis, we evaluated the utility of Wnt5A in antigen processing, cross-presentation, and CD8 T cell activation. Using mouse bone marrow-derived dendritic cells as antigen-presenting cells and ovalbumin as a model antigen we found that Wnt5A mediated regulation of actin and proteasome dynamics is inherently associated with antigen processing. A Wnt5A-Actin-Protasome axis also contributes to antigen cross-presentation and antigen responsive CD8 T cell expansion. In concurrence with these observations, we demonstrated impaired activation of ovalbumin-specific CD8 T cells in ovalbumin immunized Wnt5A heterozygous mice as illustrated by their poor CD8 T cell recall response to ovalbumin when compared to similarly immunized wild type cohorts. Our results suggest that Wnt5A signaling-directed antigen processing/presentation could be vital for generating CD8 T cell recall response to antigen, thus shedding light on a critical parameter of immunity.

scholarly journals A gammaherpesvirus-secreted activator of Vβ4+ CD8+ T cells regulates chronic infection and immunopathology

2008 ◽  
Vol 205 (3) ◽  
pp. 669-684 ◽  
Author(s):  
Andrew G. Evans ◽  
Janice M. Moser ◽  
Laurie T. Krug ◽  
Veranika Pozharskaya ◽  
Ana L. Mora ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd8 T Cells ◽  
Cell Response ◽  
Cell Activation ◽  
Cd8 T Cell ◽  
T Cell Response ◽  
Murine Gammaherpesvirus

Little is known about herpesvirus modulation of T cell activation in latently infected individuals or the implications of such for chronic immune disorders. Murine gammaherpesvirus 68 (MHV68) elicits persistent activation of CD8+ T cells bearing a Vβ4+ T cell receptor (TCR) by a completely unknown mechanism. We show that a novel MHV68 protein encoded by the M1 gene is responsible for Vβ4+ CD8+ T cell stimulation in a manner reminiscent of a viral superantigen. During infection, M1 expression induces a Vβ4+ effector T cell response that resists functional exhaustion and appears to suppress virus reactivation from peritoneal cells by means of long-term interferon-γ (IFNγ) production. Mice lacking an IFNγ receptor (IFNγR−/−) fail to control MHV68 replication, and Vβ4+ and CD8+ T cell activation by M1 instead contributes to severe inflammation and multiorgan fibrotic disease. Thus, M1 manipulates the host CD8+ T cell response in a manner that facilitates latent infection in an immunocompetent setting, but promotes disease during a dysregulated immune response. Identification of a viral pathogenecity determinant with superantigen-like activity for CD8+ T cells broadens the known repertoire of viral immunomodulatory molecules, and its function illustrates the delicate balance achieved between persistent viruses and the host immune response.

scholarly journals The circadian clock of CD8 T cells modulates their early response to vaccination and the rhythmicity of related signaling pathways

2019 ◽  
Vol 116 (40) ◽  
pp. 20077-20086 ◽  
Author(s):  
Chloé C. Nobis ◽  
Geneviève Dubeau Laramée ◽  
Laura Kervezee ◽  
Dave Maurice De Sousa ◽  
Nathalie Labrecque ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Signaling Pathways ◽  
T Cell Activation ◽  
Cd8 T Cells ◽  
Cell Response ◽  
Cell Activation ◽  
Cd8 T Cell ◽  
Time Of Day ◽  
T Cell Response

Circadian variations of various aspects of the immune system have been described. However, the circadian control of T cells has been relatively unexplored. Here, we investigated the role of circadian clocks in regulating CD8 T cell response to antigen presentation by dendritic cells (DCs). The in vivo CD8 T cell response following vaccination with DCs loaded with the OVA257–264 peptide antigen (DC-OVA) leads to a higher expansion of OVA-specific T cells in response to vaccination done in the middle of the day, compared to other time points. This rhythm was dampened when DCs deficient for the essential clock gene Bmal1 were used and abolished in mice with a CD8 T cell-specific Bmal1 deletion. Thus, we assessed the circadian transcriptome of CD8 T cells and found an enrichment in the daytime of genes and pathways involved in T cell activation. Based on this, we investigated early T cell activation events. Three days postvaccination, we found higher T cell activation markers and related signaling pathways (including IRF4, mTOR, and AKT) after a vaccination done during the middle of the day compared to the middle of the night. Finally, the functional impact of the stronger daytime response was shown by a more efficient response to a bacterial challenge at this time of day. Altogether, these results suggest that the clock of CD8 T cells modulates the response to vaccination by shaping the transcriptional program of these cells and making them more prone to strong and efficient activation and proliferation according to the time of day.

scholarly journals High CD8+ T Cell Activation Marks a Less Differentiated HIV-1 Specific CD8+ T Cell Response that Is Not Altered by Suppression of Viral Replication

PLoS ONE ◽  
2009 ◽  
Vol 4 (2) ◽  
pp. e4408 ◽  
Author(s):  
Jason D. Barbour ◽  
Lishomwa C. Ndhlovu ◽  
Qi Xuan Tan ◽  
Terence Ho ◽  
Lorrie Epling ◽  
...  
Keyword(s):  
T Cell ◽  
Viral Replication ◽  
T Cell Activation ◽  
Cell Response ◽  
Cell Activation ◽  
Cd8 T Cell ◽  
T Cell Response ◽  
Hiv 1

scholarly journals An epidemic Zika virus isolate suppresses antiviral immunity by disrupting antigen presentation pathways

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ryan D. Pardy ◽  
Stefanie F. Valbon ◽  
Brendan Cordeiro ◽  
Connie M. Krawczyk ◽  
Martin J. Richer
Keyword(s):  
T Cell ◽  
Zika Virus ◽  
Cell Response ◽  
Cd8 T Cell ◽  
T Cell Response ◽  
Cross Presentation ◽  
Cell Immunity ◽  
Asian Lineage ◽  
Insight Into ◽  
Host Tissues

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.

Development and characterization of a HCMV multiantigen therapeutic vaccine for GBM using the UNITE platform.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e14565-e14565
Author(s):  
Amit Adhikari ◽  
Juliete Macauley ◽  
Yoshimi Johnson ◽  
Mike Connolly ◽  
Tim Coleman ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
T Cells ◽  
T Cell ◽  
Tumor Microenvironment ◽  
Mouse Model ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cd8 T Cell ◽  
T Cell Response

e14565 Background: Glioblastoma (GBM) is an aggressive form of brain cancer with a median survival of 15 months which has remained unchanged despite technological advances in the standard of care. GBM cells specifically express human cytomegalovirus (HCMV) proteins providing a unique opportunity for targeted therapy. Methods: We utilized our UNITE (UNiversal Intracellular Targeted Expression) platform to develop a multi-antigen DNA vaccine (ITI-1001) that codes for the HCMV proteins- pp65, gB and IE-1. The UNITE platform involves lysosomal targeting technology, fusing lysosome-associated protein 1 (LAMP1) with target antigens resulting in increased antigen presentation by MHC-I and II. ELISpot, flow cytometry and ELISA techniques were used to evaluate the vaccine immunogenicity and a syngeneic, orthotopic GBM mouse model that expresses HCMV proteins was used for efficacy studies. The tumor microenvironment studies were done using flow cytometry and MSD assay. Results: ITI-1001 vaccination showed a robust antigen-specific CD4 and CD8 T cell response in addition to a strong humoral response. Using GBM mouse model, therapeutic treatment of ITI-1001 vaccine resulted in ̃56% survival with subsequent long-term immunity. Investigating the tumor microenvironment showed significant CD4 T cell infiltration as well as enhanced Th1 and CD8 T cell activation. Regulatory T cells were also upregulated upon ITI-1001 vaccination and would be an attractive target to further improve this therapy. In addition, tumor burden negatively correlated with number of activated CD4 T cells (CD4 IFNγ+) reiterating the importance of CD4 activation in ITI-1001 efficacy and potentially identifying treatment responders and non-responders. Further characterization of these two groups showed high infiltration of CD3+, CD4+ and CD8+ T cells in responders compared with non- responders along with higher CD8 T cell activation. Conclusions: Thus, we show that vaccination with HCMV antigens using the ITI-1001-UNITE platform generates strong cellular and humoral immune responses, triggering significant anti-tumor activity that leads to enhanced survival in mice with GBM.

scholarly journals Acidosis-Induced TGF-β2 Production Promotes Lipid Droplet Formation in Dendritic Cells and Alters Their Potential to Support Anti-Mesothelioma T Cell Response

Cancers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1284
Author(s):  
Natalia Trempolec ◽  
Charline Degavre ◽  
Bastien Doix ◽  
Davide Brusa ◽  
Cyril Corbet ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
T Cell ◽  
Lipid Droplet ◽  
T Cell Activation ◽  
Cell Response ◽  
Cell Activation ◽  
Transforming Growth Factor ◽  
T Cell Response ◽  
Mesenchymal Transition

For poorly immunogenic tumors such as mesothelioma there is an imperious need to understand why antigen-presenting cells such as dendritic cells (DCs) are not prone to supporting the anticancer T cell response. The tumor microenvironment (TME) is thought to be a major contributor to this DC dysfunction. We have reported that the acidic TME component promotes lipid droplet (LD) formation together with epithelial-to-mesenchymal transition in cancer cells through autocrine transforming growth factor-β2 (TGF-β2) signaling. Since TGF-β is also a master regulator of immune tolerance, we have here examined whether acidosis can impede immunostimulatory DC activity. We have found that exposure of mesothelioma cells to acidosis promotes TGF-β2 secretion, which in turn leads to LD accumulation and profound metabolic rewiring in DCs. We have further documented how DCs exposed to the mesothelioma acidic milieu make the anticancer vaccine less efficient in vivo, with a reduced extent of both DC migratory potential and T cell activation. Interestingly, inhibition of TGF-β2 signaling and diacylglycerol O-acyltransferase (DGAT), the last enzyme involved in triglyceride synthesis, led to a significant restoration of DC activity and anticancer immune response. In conclusion, our study has identified that acidic mesothelioma milieu drives DC dysfunction and altered T cell response through pharmacologically reversible TGF-β2-dependent mechanisms.

scholarly journals Differential expression of predisposing HLA-DQ2.5 alleles in DR5/DR7 celiac disease patients affects the pathological immune response to gluten

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Laura Pisapia ◽  
Stefania Picascia ◽  
Federica Farina ◽  
Pasquale Barba ◽  
Carmen Gianfrani ◽  
...  
Keyword(s):  
Celiac Disease ◽  
T Cell ◽  
Differential Expression ◽  
T Cell Activation ◽  
Cell Response ◽  
Cell Activation ◽  
T Cell Response ◽  
Risk Alleles ◽  
Personalized Diagnosis ◽  
Antigen Presenting

Abstract The DR5-DQ7/DR7-DQ2 genotype is very frequent among patients affected by celiac disease (CD), in Europe. This genotype, associated to high risk of CD, carries the HLA-DQA1*05 and HLA-DQB1*02 predisposing alleles, in trans configuration. The alleles encode the DQ2.5 heterodimer responsible of gluten peptide presentation on the surface of antigen-presenting cells (APCs), and consequent pathogenic CD4+ T cell activation. We demonstrated that DR5/DR7 APCs induce an anti-gluten CD4+ T cell response, of comparable intensity to that observed with APCs carrying DR1/DR3 genotype, which risk alleles are in cis configuration. In addition, we showed that DR5/DR7 APCs from celiac patients stimulated an effector CD4+ T cell response higher with respect to that induced by DR5/DR7 APCs from healthy subjects. To explain these findings, we assessed the DQ2.5 RNA and protein quantity. We showed that the expression of DQA1*05 and DQB1*02 risk alleles is much higher than the expression of non-CD-associated alleles, in agreement with the previous results obtained with DR1/DR3 genotype. The differential expression of transcripts influences the quantity of DQα1*05 and DQβ1*02 chains and, as consequence, the cell surface density of DQ2.5 heterodimers. Moreover, both RNA and proteins, are more abundant in APCs from celiac patients than controls. Finally, to unravel the mechanism regulating the expression of predisposing DQA1*05 and DQB1*02 alleles, we quantified the new synthetized RNA and found that the differential expression is explained by their transcription rate. Our results confirmed that the strength of antigen-specific CD4+ T cell response is mainly determined by the amount of gluten in the diet and provided a new possible approach for a personalized diagnosis and for risk stratification.

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