Biology subjects

Eiz-Vesper, B.

Publications and source records attributed to Eiz-Vesper, B..

3 recordsLinked to original sources

bioRxiv2023

DNA methylation profiling identifies TBKBP1 as potent amplifier of cytotoxic activity in CMV-specific human CD8+ T cells

Epigenetic mechanisms stabilize gene expression patterns during CD8+ T cell differentiation. However, although adoptive transfer of virus-specific T cells is clinically applied to reduce the risk of virus infection or reactivation in immunocompromised individuals, the DNA methylation pattern of virus-specific CD8+ T cells is largely unknown. Hence, we here performed whole-genome bisulfite sequencing of cytomegalovirus-specific human CD8+ T cells and found that they display a unique DNA methylation pattern consisting of 79 differentially methylated regions when compared to bulk memory CD8+ T cells. Among them was TBKBP1, coding for TBK-binding protein 1 that can interact with TANK-binding kinase 1 (TBK1) and mediate pro-inflammatory responses in innate immune cells downstream of intracellular virus sensing. Since TBKBP1 has not yet been reported in T cells, we aimed to unravel its role in virus-specific CD8+ T cells. TBKBP1 demethylation in terminal effector CD8+ T cells correlated with TBKBP1 expression and was stable upon long-term in vitro culture. TBKBP1 overexpression resulted in enhanced TBK1 phosphorylation upon stimulation of CD8+ T cells and significantly improved their virus neutralization capacity. Collectively, our data demonstrate that TBKBP1 modulates virus-specific CD8+ T cell responses and could be exploited as therapeutic target to improve adoptive T cell therapies.

immunology↗

bioRxiv2023

Depletion of alloreactive B cells by chimeric alloantigen receptor T cells with drug resistance to prevent antibody-mediated rejection in solid organ transplantation

In the present study, we developed a novel cell therapy approach to selectively combat antibody-mediated rejection (AMR), a major and unresolved complication after solid organ transplantation (SOT) caused by donor-HLA-specific, alloreactive B cells. Current treatment options including B-cell depletion protocols are inefficient and result in complete loss of humoral immunity. To selectively eliminate alloreactive B cells characterized by corresponding anti-donor-HLA B-cell receptors (BCRs), we engineered T cells with a novel chimeric receptor comprising a truncated HLA molecule fused to intracellular 4-1BB/CD3{xi} signaling domains to generate T cells overcoming rejection by antibodies (CORA-Ts). As proof-of-concept, CORA receptors based on HLA-A*02 were shown to bind anti-HLA-A*02 antibodies from the serum of kidney transplant recipients, indicating their suitability to also target the respective membrane-bound anti-HLA-A*02 BCRs on alloreactive B cells. In co-cultures with B-cell lines expressing and releasing anti-HLA-A*02 antibodies, CORA-Ts were specifically activated, released pro-inflammatory cytokines (e.g. IFN-{gamma}, granzyme B), and exhibited strong cytotoxicity resulting in an effective reduction of anti-HLA-A*02 antibody release. A modification of the HLA-A*02 3-domain within the CORA receptor effectively abrogated T-cell sensitization. Additionally, using CRISPR/Cas9-mediated knockout of a selected binding protein, CORA-Ts were able to resist immunosuppressive treatment to ensure high efficiency in transplant patients. Our results demonstrate that CORA-Ts are able to specifically recognize and eliminate alloreactive B cells, and thus selectively prevent formation of anti-HLA antibodies even under immunosuppressive conditions. This suggests CORA-Ts as potent novel approach to specifically combat AMR and improve long-term graft survival in SOT patients while preserving their overall B-cell immunity.

immunology↗

bioRxiv2023

Dynamic monitoring of viral gene expression reveals rapid antiviral effects of CD8 T cells recognizing the HCMV-pp65 antigen

Human Cytomegalovirus (HCMV) is a betaherpesvirus that causes severe disease in immunocompromised transplant recipients. Immunotherapy with CD8 T cells specific for HCMV antigens presented on HLA class-I molecules is explored as strategy for long-term relief to such patients, but the antiviral effectiveness of T cell preparations cannot be efficiently predicted by available methods. Therefore, we developed an Assay for Rapid Measurement of Antiviral T-cell Activity (ARMATA) by real-time automated fluorescent microscopy and used it to study the ability of CD8 T cells to neutralize HCMV and control its spread. As a proof of principle, we used TCR-transgenic T cells specific for the immunodominant HLA-A02-restricted tegumental phosphoprotein pp65. pp65 expression follows an early/late kinetic, but it is not clear at which stage of the virus cycle it acts as an antigen. We measured control of HCMV infection by T cells as early as 6 hours post infection (hpi). The timing of the antigen recognition indicated that it occurred before the late phase of the virus cycle, but also that virion-associated pp65 was not recognized during virus entry into cells. Monitoring of pp65 gene expression dynamics by reporter fluorescent genes revealed that pp65 was detectable as early as 6 hpi, and that a second and much larger bout of expression occurs in the late phase of the virus cycle by 48 hpi. Since transgenic (Tg)-pp65 specific CD8 T cells were activated even when DNA replication was blocked, our data argue that pp65 acts as an early virus gene for immunological purposes. Therefore, ARMATA does not only allow same-day identification of antiviral T-cell activity, but also provides a method to define the timing of antigen recognition in the context of HCMV infection.

immunology↗