Human antimicrobial cytotoxic T lymphocytes, defined by NK receptors and antimicrobial proteins, kill intracellular bacteria
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA475765 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR7295860.fastq.gz | Fastqsanger.gz | |||
| SRR7295870.fastq.gz | Fastqsanger.gz | |||
| SRR7295880.fastq.gz | Fastqsanger.gz | |||
| SRR7295890.fastq.gz | Fastqsanger.gz | |||
| SRR7295900.fastq.gz | Fastqsanger.gz |
Items per page: 5 1 - 5 of 50 |
Similar Datasets
Project description:Human cytotoxic T cell subsets were sorted based on cytotoxic molecule expression and RNA sequencing was performed on these subsets
2018-08-31 | GSE115686 | GEO
Project description:Human CD8+ cytotoxic T lymphocytes (CTLs) contribute to antimicrobial defense against intracellular pathogens through secretion of cytotoxic granule proteins granzyme B, perforin, and granulysin. However, CTLs are heterogeneous in the expression of these proteins, and the subset(s) responsible for antimicrobial activity is unclear. Studying human leprosy, we found that the subset of CTLs coexpressing all three cytotoxic molecules is increased in the resistant form of the disease, can be expanded by interleukin-15 (IL-15), and is differentiated from naïve CD8+ T cells by Langerhans cells. RNA sequencing analysis identified that these CTLs express a gene signature that includes an array of surface receptors typically expressed by natural killer (NK) cells. We determined that CD8+ CTLs expressing granzyme B, perforin, and granulysin, as well as the activating NK receptor NKG2C, represent a population of "antimicrobial CTLs" (amCTLs) capable of T cell receptor (TCR)-dependent and TCR-independent release of cytotoxic granule proteins that mediate antimicrobial activity.
| S-EPMC6431239 | biostudies-literature
Project description:Herein, we used C. acnes as a model to elucidate the antimicrobial machinery of the TH17 subset. We generated C. acnes-specific antimicrobial TH17 clones (AMTH17) with varying antimicrobial activity against C. acnes, to enable us to study mechanisms by which TH17 cells kill bacteria. We show that C. acnes-induced AMTH17 clones represent a subset of CD4+ TEM and TEMRA cells. RNA-seq analysis of AMTH17 indicate transcripts encoding antimicrobial molecules such as GNLY, GZMB, PRF1 and histone H2B, whose expression correlates with killing activity. Additionally, we validated that AMTH17-mediated killing is a general mechanism that can target C. acnes and other bacterial species. Scanning electron microscopy reveal that AMTH17s can release T cell extracellular traps composed of lysine and arginine-rich histones such as H2B and H4 that entangle C. acnes. This study identifies a functionally distinct subpopulation of TH17 cells with an ability to secrete antimicrobial proteins and form extracellular T cell traps to capture and kill bacteria.
2021-12-01 | GSE144852 | GEO
Project description:Cytotoxic T lymphocytes (CTL) kill malignant and infected cells via cytotoxic proteins such as granzyme B (GzmB) that are released into the immunological synapse in the form of ~110 nm supramolecular attack particles (SMAPs). However, it is not known where SMAPs are stored in the cell and how they are released. To address this, we utilized knock-in mice to label fusogenic cytotoxic granules with synaptobrevin2-mRFP. We identified two classes of fusion-competent granules, single core granules (SCG) and multi core granules (MCG), with different diameter, morphology, and protein composition. Functional analyses demonstrate that both classes of granules fuse with the plasma membrane at the IS. SCG fusion resulted in rapid dispersal of GzmB. MCG labelled with the SMAP marker thrombospondin-1 and their fusion events resulted in deposition of SMAPs. The CTL attack strategy thus includes SCG fusion to disperse immediately active cytotoxic proteins and parallel MCG fusion to deposit concentrated latent SMAPs onto the target.
2022-04-04 | PXD025055 | Pride
Project description:Ceragenins are a family of synthetic amphipathic molecules designed to mimic the properties of naturally-occurring cationic antimicrobial peptides (CAMPs). Although ceragenins have potent antimicrobial activity, whether their mode of action is similar to that of CAMPs has remained elusive. Here we report the results of a comparative study of the bacterial responses to two well-studied CAMPs, LL37 and colistin, and two ceragenins with related structures, CSA13 and CSA13.
2022-01-10 | PXD022149 | Pride
Project description:Protozoan infections are a serious global health problem. Natural killer (NK) cells and cytolytic T lymphocytes (CTLs) eliminate pathogen-infected cells by releasing cytolytic granule contents--granzyme (Gzm) proteases and the pore-forming perforin (PFN)--into the infected cell. However, these cytotoxic molecules do not kill intracellular parasites. CD8(+) CTLs protect against parasite infections in mice primarily by secreting interferon (IFN)-?. However, human, but not rodent, cytotoxic granules contain the antimicrobial peptide granulysin (GNLY), which selectively destroys cholesterol-poor microbial membranes, and GNLY, PFN and Gzms rapidly kill intracellular bacteria. Here we show that GNLY delivers Gzms into three protozoan parasites (Trypanosoma cruzi, Toxoplasma gondii and Leishmania major), in which the Gzms generate superoxide and inactivate oxidative defense enzymes to kill the parasite. PFN delivers GNLY and Gzms into infected cells, and GNLY then delivers Gzms to the intracellular parasites. Killer cell-mediated parasite death, which we term 'microbe-programmed cell death' or 'microptosis', is caspase independent but resembles mammalian apoptosis, causing mitochondrial swelling, transmembrane potential dissipation, membrane blebbing, phosphatidylserine exposure, DNA damage and chromatin condensation. GNLY-transgenic mice are protected against infection by T. cruzi and T. gondii, and survive infections that are lethal to wild-type mice. Thus, GNLY-, PFN- and Gzm-mediated elimination of intracellular protozoan parasites is an unappreciated immune defense mechanism.
| S-EPMC7325279 | biostudies-literature
Project description:Cytotoxic lymphocytes (CTL) have been reported to show a range of motility patterns from rapid long-range tracking to complete arrest, but how and whether these kinematics affect their ability to kill target cells is not known. Many in vitro killing assays utilize cell lines and tumour-derived cells as targets, which may be of limited relevance to the kinetics of CTL-mediated killing of somatic cells. Here, live-cell microscopy is used to examine the interactions of CTL and primary murine skin cells presenting antigens. We developed a qualitative and quantitative killing assay using extended-duration fluorescence time-lapse microscopy coupled with large-volume objective software-based data analysis to obtain population data of cell-to-cell interactions, motility and apoptosis. In vivo and ex vivo activated antigen-specific cytotoxic lymphocytes were added to primary keratinocyte targets in culture with fluorometric detection of caspase-3 activation in targets as an objective determinant of apoptosis. We found that activated CTL achieved contact-dependent apoptosis of non-tumour targets after a period of prolonged attachment - on average 21 hours - which was determined by target cell type, amount of antigen, and activation status of CTL. Activation of CTL even without engagement of the T cell receptor was sufficient to mobilise cells significantly above baseline, while the addition of cognate antigen further enhanced their motility. Highly activated CTL showed markedly increased vector displacement, and velocity, and lead to increased antigen-specific target cell death. These data show that the inherent kinematics of CTL correlate directly with their ability to kill non-tumour cells presenting cognate antigen.
| S-EPMC4011687 | biostudies-literature
Project description:When killer lymphocytes recognize infected cells, perforin delivers cytotoxic proteases (granzymes) into the target cell to trigger apoptosis. What happens to intracellular bacteria during this process is unclear. Human, but not rodent, cytotoxic granules also contain granulysin, an antimicrobial peptide. Here, we show that granulysin delivers granzymes into bacteria to kill diverse bacterial strains. In Escherichia coli, granzymes cleave electron transport chain complex I and oxidative stress defense proteins, generating reactive oxygen species (ROS) that rapidly kill bacteria. ROS scavengers and bacterial antioxidant protein overexpression inhibit bacterial death. Bacteria overexpressing a GzmB-uncleavable mutant of the complex I subunit nuoF or strains that lack complex I still die, but more slowly, suggesting that granzymes disrupt multiple vital bacterial pathways. Mice expressing transgenic granulysin are better able to clear Listeria monocytogenes. Thus killer cells play an unexpected role in bacterial defense.
| S-EPMC4090916 | biostudies-literature
Project description:Recent work in immunometabolism has emphasised the role of mitochondria in both the innate and adaptive immune system. Mitochondria are important in T cell development and differentiation, but less is known about their role in CD8+ effector T cells (CTLs). We found that CTLs that lack the mitochondrial deubiquitinase USP30 undergo promiscuous mitophagy, destroying most of the cellular mitochondria. Surprisingly, this results in a markedly diminished killing capacity, while motility, signalling and secretion remain intact. This study uses quantitative DIA proteomics to measure the impact of USP30 deficiency on the global proteome of IL-2 maintained, 4.5 h TCR retriggered and 4.5 h TCR retriggered + cycloheximide CTL. We also measured the impact of pharmacologically inhibiting mitochondrial translation by performing Quantitative DIA proteomics on IL2 maintained or TCR retriggered CTL treated with the mitochondrial translation inhibitor doxycycline for 4.5 hrs. Unexpectedly, inhibition of mitochondrial translation, through genetic or pharmacologic methods, was the mechanism by which CTL killing was impaired. Reduced mitochondrial translation triggered attenuated cytosolic translation which precluded replenishment of secreted effector molecules thereby limiting the capacity of CTLs to serially kill multiple targets. Thus, mitochondria emerge as a previously unappreciated homeostatic regulator of protein translation required for serial CTL killing.
2022-06-09 | PXD026948 | Pride
Project description:UnlabelledCD56+ natural killer (NK) and CD56+ T cells, from sputum or bronchoalveolar lavage of subjects with chronic obstructive pulmonary disease (COPD) are more cytotoxic to highly susceptible NK targets than those from control subjects. Whether the same is true in lung parenchyma, and if NK activity actually contributes to emphysema progression are unknown. To address these questions, we performed two types of experiments on lung tissue from clinically-indicated resections (n = 60). First, we used flow cytometry on fresh single-cell suspension to measure expression of cell-surface molecules (CD56, CD16, CD8, NKG2D and NKp44) on lung lymphocytes and of the 6D4 epitope common to MICA and MICB on lung epithelial (CD326+) cells. Second, we sequentially isolated CD56+, CD8+ and CD4+ lung lymphocytes, co-cultured each with autologous lung target cells, then determined apoptosis of individual target cells using Annexin-V and 7-AAD staining. Lung NK cells (CD56+ CD3-) and CD56+ T cells (CD56+ CD3+) were present in a range of frequencies that did not differ significantly between smokers without COPD and subjects with COPD. Lung NK cells had a predominantly "cytotoxic" CD56+ CD16+ phenotype; their co-expression of CD8 was common, but the percentage expressing CD8 fell as FEV1 % predicted decreased. Greater expression by autologous lung epithelial cells of the NKG2D ligands, MICA/MICB, but not expression by lung CD56+ cells of the activating receptor NKG2D, correlated inversely with FEV1 % predicted. Lung CD56+ lymphocytes, but not CD4+ or CD8+ conventional lung T cells, rapidly killed autologous lung cells without additional stimulation. Such natural cytotoxicity was increased in subjects with severe COPD and was unexplained in multiple regression analysis by age or cancer as indication for surgery. These data show that as spirometry worsens in COPD, CD56+ lung lymphocytes exhibit spontaneous cytotoxicity of autologous structural lung cells, supporting their potential role in emphysema progression.Trial registrationClinicalTrials.gov NCT00281229.
| S-EPMC4117545 | biostudies-literature