Dataset Information

Translational repression of pre-formed cytokine mRNA prevents chronic activation of memory T cells

ABSTRACT: Memory T cells are critical to protect us from recurring infections. Their instantaneous reactivity to pathogens is empowered by persistent expression of cytokine mRNA. How aberrant protein production of this pre-formed mRNA is prevented in the absence of infection, however, remains unresolved. We show that protein production in memory T cells is blocked through a 3’untranslated region (3’UTR)-mediated process, and that AU-rich elements (AREs) are key herein. Germ-line deletion of AREs leads to chronic IFN- production in bona fide memory T cells. Strikingly, the aberrant protein production does not result from increased mRNA levels and/or half-life. Rather, AREs block the recruitment of cytokine mRNA to ribosomes, a process that is mediated by the ARE-binding protein ZFP36L2. Thus, AREs are crucial elements for translational repression that allow murine and human memory T cells to contain pre-formed cytokine mRNAs, while preventing undesirable protein production in the absence of infection.

INSTRUMENT(S): Orbitrap Fusion ETD

ORGANISM(S): Mus Musculus (mouse)

TISSUE(S): Spleen, T Cell

SUBMITTER: Maartje van den Biggelaar

LAB HEAD: Maartje van den Biggelaar

PROVIDER: PXD008051 | Pride | 2018-05-15

REPOSITORIES: Pride

ACCESS DATA

Publications

Translational repression of pre-formed cytokine-encoding mRNA prevents chronic activation of memory T cells.

Salerno Fiamma F Engels Sander S van den Biggelaar Maartje M van Alphen Floris P J FPJ Guislain Aurelie A Zhao Wanqi W Hodge Deborah L DL Bell Sarah E SE Medema Jan Paul JP von Lindern Marieke M Turner Martin M Young Howard A HA Wolkers Monika C MC

Nature immunology 20180709 8

Memory T cells are critical for the immune response to recurring infections. Their instantaneous reactivity to pathogens is empowered by the persistent expression of cytokine-encoding mRNAs. How the translation of proteins from pre-formed cytokine-encoding mRNAs is prevented in the absence of infection has remained unclear. Here we found that protein production in memory T cells was blocked via a 3' untranslated region (3' UTR)-mediated process. Germline deletion of AU-rich elements (AREs) in th ...[more]

PMID: 29988089

Similar Datasets

Project description:Recently, several neutralizing anti-HIV antibodies have been isolated from memory B cells of HIV-infected individuals. However, despite extensive evidence of B-cell dysfunction in HIV disease, little is known about the cells from which these rare HIV-specific antibodies originate. Accordingly, HIV envelope gp140 and CD4 or co-receptor (CoR) binding site (bs) mutant probes were used to evaluate HIV-specific responses in the peripheral blood B cells of individuals at various stages of infection. In contrast to non-HIV responses, HIV-specific responses against gp140 were enriched within abnormal B cells, namely activated and exhausted memory subsets, which are largely absent in the blood of uninfected individuals. Responses against the CoRbs (a poorly-neutralizing epitope) arose early whereas those against the CD4bs (a well-characterized neutralizing epitope) were delayed and infrequent. Enrichment of the HIV-specific response within resting memory B cells, the predominant subset in uninfected individuals, did occur in certain infected individuals who maintained low levels of plasma viremia and immune activation with or without antiretroviral therapy. These findings were corroborated by transcriptional profiles. Taken together, our findings provide valuable insight into virus-specific B-cell responses in HIV infection and demonstrate that memory B-cell abnormalities may contribute to the ineffectiveness of the antibody response in infected individuals. HIV-specific responses against gp140 were enriched within abnormal B cells, namely activated (AM) and exhausted (tissue-like; TLM) memory subsets, which are largely absent in the blood of uninfected individuals. These responses are highest during the early stage of HIV infection, significantly decreased following the initiation of antiretroviral therapy (ART), and most importantly, enriched in normal resting memory B cells (RM) when HIV viremia and immune activation are controlled either naturally or as a result of ART. These HIV-specific B cells (AM and TLM) and resting memory B cells (RM) were sorted from peripheral blood mononuclear cells (PBMCs) of 6 HIV infected individuals. In addition, gp140-specific IgG+ B cells were sorted from individuals with either a strong (n= 6) or weak (n= 6) pro-resting memory profile. TaqMan gene expression assay was performed on these HIV-specific B cells and B cell subset. The array consisted of 29 genes.

Project description:Memory B cells represent one of the pillar of humoral protection and are found in the circulation and secondary lymphoid organs several decades after initial pathogen or vaccine encounter. The exact cellular and biological mechanisms allowing long-term survival of quiescent cells in such a fluctuating microenvironment remain poorly understood. Assessing the true longevity of human memory B cells against common pathogens is, in most settings, hindered by the possibility for any given individual to re-encounter them during his lifetime. Smallpox, officially declared eradicated in 1980 (Fenner WHO 1988), represents one notable exception. Alongside smallpox eradication, anti-smallpox vaccination, based on the live Vaccinia virus, was progressively discontinued during the 1970s. As such, any detectable anti-vaccinia memory B cell in an individual post 2010 would likely have been generated more than 40 years ago, without any re-stimulation with the immunizing antigen during that timeframe. Anti-vaccinia antibodies serum titers remain stable in human for more than 80 years after first vaccination (Amanna NEJM 2007, PMID: 17989383), with several identified immunodominant epitopes including the envelope glycoprotein B5R (Lantto J Virol 2011, PMID: 21147924). Anti-vaccinia memory B cells have similarly been followed longitudinally in the blood for up to 65 years post vaccination (Amanna NEJM 2007, PMID: 17989383 ; Crotty JI 2003, PMID : 14607890) and, following a contraction phase taking place in the first couple of years after immunization, reach a remarkably stable plateau that last for decades at around 0.1% of total circulating IgG+ memory B cells. Functional analysis of such long-lived memory B cells, however, is still lacking. As a proxy to study long-lived memory B cells, IgG+ switched memory B cells specific for the immunodominant Vaccinia antigen B5R (B5R+ IgG+ memory B cells) were sorted and analyzed by scRNAseq from the spleen of six organ donors, collected between 2015 and 2018. For all donors, B5R+ IgG+ memory B cells were sorted alongside total IgG+ memory B cells (live IgD-CD27+IgG+CD20+CD3-CD14-CD16-) and naïve B cells (live IgD+CD27-CD38-CD24-CD20+CD3-CD14-CD16-). Single-cell mRNA sequencing was performed according to an adapted version of the SORT-seq protocol (Muraro et al., 2016, PMID: 27693023), with cDNA libraries generation, sequencing and reads alignment performed at Single Cell Discoveries (Utrecht, Netherlands).

Project description:Rituximab (RTX) is widely used as a first-line therapeutic strategy in B cell-mediated autoimmune diseases. However, a large proportion of patients either do not respond to the treatment or relapse during B cell reconstitution. Primary immune thrombocytopenia (ITP) is a prototypic B cell mediated autoimmune disease in which pathogenic antibodies directed against the platelet membrane glycoprotein IIb-IIIa (GPIIbIIIa) lead to platelet destruction by macrophages in the spleen. In ITP, RTX-mediated B-cell depletion leads to an immediate clinical response in 50% of patients but 80% of patients will subsequently relapse in the next following months. Patients failing to respond or relapsing after RTX treatment are splenectomized when alternative therapies are inefficient or unavailable. Therapeutic splenectomy, resulting in a durable platelet response in 60-70 % of ITP patients, offers a unique access to study the autoimmune response in the spleen. To understand the cellular basis of disease's relapse in secondary lymphoid organs in humans, memory B cells were sorted and analyzed by scRNAseq from the spleen of three different groups of splenectomized ITP patients: 1) Patients that achieved a complete response after a course of RTX and relapsed during B-cell reconstitution (hereafter referred to as “RTX relapse” patients), 2) patients with primary failure of RTX, i.e. who did not respond to treatment at the time of B-cell depletion (“RTX failure” patients), 3) patients with active ITP that were not treated with RTX (“ITP” patients). All were compared with sorted splenic memory B cells from organ donors with no immune disease who died from stroke or head trauma, hereafter referred to as healthy donors (“HD” patients). We also included in this analysis splenic memory B cells from children with sickle cell disease that underwent splenectomy and are known to have a high frequency of B cell activation secondary to classical childhood infections and vaccinations, reflected by an increased number of GC. Single-cell mRNA sequencing was performed according to an adapted version of the SORT-seq protocol (Muraro et al., 2016, Cell Systems 3, 385–394), with cDNA libraries generation, sequencing and reads alignment performed at Single Cell Discoveries (Utrecht, Netherlands).

Dataset Information

Translational repression of pre-formed cytokine mRNA prevents chronic activation of memory T cells

Publications

Translational repression of pre-formed cytokine-encoding mRNA prevents chronic activation of memory T cells.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure