scholarly journals Cell responses to simulated microgravity and hydrodynamic stress can be distinguished by using comparative transcriptomic analysis

2021 ◽  
Author(s):  
Nikolai V Kouznetsov

The human immune system is compromised in microgravity (MG) conditions during an orbital flight and upon return to Earth. T cells are critical for the immune response and execute their functions via actin mediated immune cell-cell interactions that could be disturbed by MG conditions. Here, we have applied two rotational platforms to simulate MG conditions: fast rotating clinostat (CL) and random positioning machine (RPM) followed by global T cell transcriptome analysis using RNA sequencing. We demonstrate that the T cell transcriptome profile in response to simulated MG treatment was clearly distinguishable from the T cell transcriptome response to hydrodynamic stress (HS) induced by shear forces upon cell movement in cultural medium. Gene expression profiling of genes related to or involved in actin cytoskeleton networks using RT-qPCR confirmed two sets of differentially regulated genes in the T cell response to MG or to HS. Several key genes potentially involved in T cell gravisensing (Fam163b, Dnph1, Trim34, Upk-1b) were identified. A number of candidate biomarker genes of the response to MG (VAV1, VAV2, VAV3, and NFATC2) and of the response to HS (ITGAL, ITGB1, ITGB2, RAC1 and RAC2) could be used to distinguish between these processes on the gene transcription level. Together, MG induces changes in the overall transcriptome of T cells leading to specific shifts in expression of cytoskeletal network genes.

2021 ◽  
Author(s):  
Joshua M Ames ◽  
Tejabhiram Yadavalli ◽  
Chandrashekhar Patil ◽  
James Hopkins ◽  
Ilina Bhattacharya ◽  
...  

Herpes stromal keratitis (HSK) is a result of the inflammatory sequelae following primary and recurrent Herpes simplex virus type-1 (HSV-1) infections. This pathology is known to be mediated by immunopathogenic T cell responses against viral antigens, however most individuals infected with HSV-1 never exhibit signs of this immunopathology. Recent studies have identified the host restriction factor, optineurin (OPTN), as an inhibitor of viral spread in the central nervous system, protecting hosts from viral encephalopathy. In an HSV-1 corneal infection mouse model on OPTN knockout mice, we assess the contribution of OPTN to ameliorating the clinical manifestations of HSK. We identify that OPTN protects the host from loss of ocular and whisker sensitivity and opacification of the cornea. scRNA-seq of the trigeminal ganglion (TG) reveals that transcription changes to the peripheral neurons and immune cell populations drive the expression of Il-17A in CD4 and CD8 T cells, as well as increased infiltration of T cells into the TG. This leads to demyelination and the observed HSK pathology.


2020 ◽  
Author(s):  
Renpeng Ding ◽  
Shang Liu ◽  
Shanshan Wang ◽  
Huanyi Chen ◽  
Fei Wang ◽  
...  

AbstractPD-L1 expression levels in tumors do not consistently predict cancer patients’ response to PD-(L)1 inhibitors. We therefore evaluated how tumor PD-L1 levels affect the anti-PD-(L)1 efficacy and T cell function. We used MART-1-specific TCR-T cells (TCR-TMART-1) stimulated with MART-127-35 peptide-loaded MEL-526 tumor cells with different proportions of them expressing PD-L1 to perform cellular assays and high-throughput single-cell RNA sequencing. Compared to control T cells, TCR-TMART-1 were more sensitive to exhaustion and secreted lower pro-inflammatory but higher anti-inflammatory cytokines with increasing proportions of PD-L1+ tumor cells. The colocalization of T cells and tumor cells in gene clusters correlated negatively with the proportion of PD-L1+ tumor cells and positively with immune cell cytotoxicity. Moreover, elevated proportion of PD-L1+ tumor cells increased PD-L1 expression and decreased PD-1 expression on T cells and enhanced T cell death. The expression of PD-1 and PD-L1 in T cells and macrophages also correlated positively with COVID-19 severity.


2021 ◽  
Vol 478 (24) ◽  
pp. 4187-4202
Author(s):  
Camila R. R. Barbosa ◽  
Justin Barton ◽  
Adrian J. Shepherd ◽  
Michele Mishto

Throughout its evolution, the human immune system has developed a plethora of strategies to diversify the antigenic peptide sequences that can be targeted by the CD8+ T cell response against pathogens and aberrations of self. Here we provide a general overview of the mechanisms that lead to the diversity of antigens presented by MHC class I complexes and their recognition by CD8+ T cells, together with a more detailed analysis of recent progress in two important areas that are highly controversial: the prevalence and immunological relevance of unconventional antigen peptides; and cross-recognition of antigenic peptides by the T cell receptors of CD8+ T cells.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Josephine F. Reijneveld ◽  
Mira Holzheimer ◽  
David C. Young ◽  
Kattya Lopez ◽  
Sara Suliman ◽  
...  

AbstractThe cell wall of Mycobacterium tuberculosis is composed of diverse glycolipids which potentially interact with the human immune system. To overcome difficulties in obtaining pure compounds from bacterial extracts, we recently synthesized three forms of mycobacterial diacyltrehalose (DAT) that differ in their fatty acid composition, DAT1, DAT2, and DAT3. To study the potential recognition of DATs by human T cells, we treated the lipid-binding antigen presenting molecule CD1b with synthetic DATs and looked for T cells that bound the complex. DAT1- and DAT2-treated CD1b tetramers were recognized by T cells, but DAT3-treated CD1b tetramers were not. A T cell line derived using CD1b-DAT2 tetramers showed that there is no cross-reactivity between DATs in an IFN-γ release assay, suggesting that the chemical structure of the fatty acid at the 3-position determines recognition by T cells. In contrast with the lack of recognition of DAT3 by human T cells, DAT3, but not DAT1 or DAT2, activates Mincle. Thus, we show that the mycobacterial lipid DAT can be both an antigen for T cells and an agonist for the innate Mincle receptor, and that small chemical differences determine recognition by different parts of the immune system.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alexander J. Dwyer ◽  
Jacob M. Ritz ◽  
Jason S. Mitchell ◽  
Tijana Martinov ◽  
Mohannad Alkhatib ◽  
...  

AbstractThe notion that T cell insulitis increases as type 1 diabetes (T1D) develops is unsurprising, however, the quantitative analysis of CD4+ and CD8+ T cells within the islet mass is complex and limited with standard approaches. Optical microscopy is an important and widely used method to evaluate immune cell infiltration into pancreatic islets of Langerhans for the study of disease progression or therapeutic efficacy in murine T1D. However, the accuracy of this approach is often limited by subjective and potentially biased qualitative assessment of immune cell subsets. In addition, attempts at quantitative measurements require significant time for manual analysis and often involve sophisticated and expensive imaging software. In this study, we developed and illustrate here a streamlined analytical strategy for the rapid, automated and unbiased investigation of islet area and immune cell infiltration within (insulitis) and around (peri-insulitis) pancreatic islets. To this end, we demonstrate swift and accurate detection of islet borders by modeling cross-sectional islet areas with convex polygons (convex hulls) surrounding islet-associated insulin-producing β cell and glucagon-producing α cell fluorescent signals. To accomplish this, we used a macro produced with the freeware software ImageJ equipped with the Fiji Is Just ImageJ (FIJI) image processing package. Our image analysis procedure allows for direct quantification and statistical determination of islet area and infiltration in a reproducible manner, with location-specific data that more accurately reflect islet areas as insulitis proceeds throughout T1D. Using this approach, we quantified the islet area infiltrated with CD4+ and CD8+ T cells allowing statistical comparison between different age groups of non-obese diabetic (NOD) mice progressing towards T1D. We found significantly more CD4+ and CD8+ T cells infiltrating the convex hull-defined islet mass of 13-week-old non-diabetic and 17-week-old diabetic NOD mice compared to 4-week-old NOD mice. We also determined a significant and measurable loss of islet mass in mice that developed T1D. This approach will be helpful for the location-dependent quantitative calculation of islet mass and cellular infiltration during T1D pathogenesis and can be combined with other markers of inflammation or activation in future studies.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A637-A637
Author(s):  
Manoj Chelvanambi ◽  
Ronald Fecek ◽  
Jennifer Taylor ◽  
Walter Storkus

BackgroundThe degree of immune infiltration in tumors, especially CD8+ T cells, greatly impacts patient disease course and response to interventional immunotherapy. Hence, enhancement of TIL prevalence is a preferred clinical endpoint, one that may be achieved via administration of agents that normalize the tumor vasculature (VN) leading to improved immune cell recruitment and/or that induce the development of local tertiary lymphoid structures (TLS) within the tumor microenvironment (TME).MethodsLow-dose STING agonist ADU S-100 (5 μg/mouse) was delivered intratumorally to established s.c. B16.F10 melanomas on days 10, 14 and 17 post-tumor inoculation under an IACUC-approved protocol. Treated and control, untreated tumors were isolated at various time points to assess transcriptional changes associated with VN and TLS formation via qPCR, with corollary immune cell composition changes determined using flow cytometry and immunofluorescence microscopy. In vitro assays were performed on CD11c+ BMDCs treated with 2.5 μg/mL ADU S-100 (vs PBS control) and associated transcriptional changes analyzed via qPCR or profiled using DNA microarrays. For TCRβ-CDR3 analyses, CDR3 was sequenced from gDNA isolated from enzymatically digested tumors and splenocytes.ResultsWe report that activation of STING within the TME leads to slowed melanoma growth in association with increased production of angiostatic factors including Tnfsf15 (Vegi), Cxcl10 and Angpt1, and TLS inducing factors including Ccl19, Ccl21, Lta, Ltb and Tnfsf14 (Light). Therapeutic responses from intratumoral STING activation were characterized by increased vascular normalization (VN), enhanced tumor infiltration by CD8+ T cells and CD11c+ DCs and local TLS neo-genesis, all of which were dependent on host expression of STING. Consistent with a central role for DC in TLS formation, ex vivo ADU S-100-activated mCD11c+ DCs also exhibited upregulated expression of TLS promoting factors including lymphotoxin-α (LTA), IL-36, inflammatory chemokines and type I interferons. TLS formation was associated with the development of a therapeutic TIL TCR repertoire enriched in T cell clonotypes uniquely detected within the tumor but not the peripheral circulation in support or local T cell cross-priming within the TME.ConclusionsOur data support the premise that i.t. delivery of STING agonist promotes a pro-inflammatory TME in support of VN and TLS formation, leading to the local expansion of unique TIL repertoire in association with superior anti-melanoma efficacy.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1365.2-1365
Author(s):  
X. Fan ◽  
D. Guo ◽  
C. T. Ng ◽  
A. Law ◽  
Z. Y. Poon ◽  
...  

Background:Patients with systemic lupus erythematosus (SLE) suffer from severe morbidity and mortality1-4, either from the disease itself or from side effects of immunosuppression5. Discovery of novel effective therapies with less toxicity is an urgent need.Objectives:The aim of this study is to elucidate the therapeutic potential and working mechanism of cytokine CXCL5 in lupus mice.Methods:Treatment with CXCL5, bone marrow (BM)-MSCs, standard of care (SOC) with combination of methylprednisolone and cyclophosphamide was given to 16-week-old Faslprmice. Mice were monitored for 10 weeks. Splenic immune cell subsets were measured by flow cytometry. Circulating cytokine and immunoglobulin were detected by Luminex technology. Renal function was evaluated by urinary spot albumin creatinine ratio. In situ renal immune cell infiltration and complement 3 deposition were detected by Haematoxylin and Eosin (H&E) staining and immunohistochemistry.Results:CXCL5 demonstrated consistent and potent immunosuppressive capacity in suppressing SLE with reduced autoantibody secretion, lymphoproliferation and preserved kidney function. With further exploration, we proved that CXCL5 reduced the proliferation of helper T cells (TH1 and TH2) in thein vitrofunctional assay. When we administrated CXCL5 to lupus mice, it promoted the proliferation of regulatory T cells and reduced the proliferation of TH17 cells, macrophages and neutrophils. Multiple proinflammatory cytokines including IL-2, IL-6, IL-12, IL-17A, KC/CXCL1, MIP-1β/CCL4 and TNF-α were also reduced. When combined with SOC, CXCL5 boosted its therapeutic effect and reduced the relevant indices of disease activity. When we correlated the effect of four different treatment groups (CXCL5, BM-MSCs, SOC, and CXCL5 plus SOC) on mice survival and target cell changes, we found that TH17 cells were the key effector cells involved in the pathogenesis of SLE.Conclusion:These findings demonstrated that CXCL5 dampens inflammation in the pre-clinical model of systemic lupus erythematosus via the orchestral effect of regulating neutrophil trafficking and suppressing helper T cell-mediated immune response. Administrating exogenous CXCL5 might be an attractive option to treat patients with lupus.References:[1]Ji S, Guo Q, Han Y, Tan G, Luo Y, Zeng F. Mesenchymal stem cell transplantation inhibits abnormal activation of Akt/GSK3beta signaling pathway in T cells from systemic lupus erythematosus mice.Cell Physiol Biochem.2012;29(5-6):705-712.[2]Peng SL. Altered T and B lymphocyte signaling pathways in lupus.Autoimmun Rev.2009;8(3):179-183.[3]Ferucci ED, Johnston JM, Gaddy JR, et al. Prevalence and incidence of systemic lupus erythematosus in a population-based registry of American Indian and Alaska Native people, 2007-2009.Arthritis Rheumatol.2014;66(9):2494-2502.[4]Jakes RW, Bae SC, Louthrenoo W, Mok CC, Navarra SV, Kwon N. Systematic review of the epidemiology of systemic lupus erythematosus in the Asia-Pacific region: prevalence, incidence, clinical features, and mortality.Arthritis Care Res (Hoboken).2012;64(2):159-168.[5]Sattwika PD, Mustafa R, Paramaiswari A, Herningtyas EH. Stem cells for lupus nephritis: a concise review of current knowledge.Lupus.2018;27(12):1881-1897.Acknowledgments:The work was supported by SMART II Centre Grant (NMRC/CG/M011/2017_SGH) and SingHealth Foundation (SHF/FG638P/2016).Disclosure of Interests:None declared


2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii214-ii214
Author(s):  
Anupam Kumar ◽  
Katharine Chen ◽  
Claudia Petritsch ◽  
Theodore Nicolaides ◽  
Mariarita Santi-Vicini ◽  
...  

Abstract The determinants of the tumor-associated immune response in brain tumors are poorly understood. Using tumor samples from two molecularly distinct subtypes of lower grade glioma, MAPK-driven glioma with biallelic inactivation of CDKN2A (n=30) and IDH-mutant, 1p/19q-intact astrocytoma (n=29), we demonstrate qualitative and quantitative differences in the tumor-associated immune response and we investigate the molecular mechanisms involved. Histologically the MAPK-driven gliomas were comprised of pleomorphic xanthoastrocytoma (PXA) (n=11) and anaplastic PXA (n=19). Seven patients had paired samples from two sequential surgeries. Immune cell populations and their activity were determined by quantitative multiplex immunostaining and Digital Spatial Profiling and gene expression was analyzed by Nanostring. Functional studies were performed using established cell lines and two new patient-derived lines from MAPK-driven LGGs. MAPK-driven tumors exhibited an increased number of CD8+ T cells and tumor-associated microglial/macrophage (TAMs), including CD163+ TAMs, as compared to IDH-mutant astrocytoma. In contrast, IDH-mutant tumors had increased FOXP3+ immunosuppressive T regulatory cells. Transcriptional and protein level analyses in MAPK-driven tumors suggested an active cytotoxic T cell response with robust expression of granzyme B, present on 27% of CD8+ T cells, increased MHC class I expression, and altered cytokine profiles. Interestingly, MAPK-driven tumors also had increased expression of immunosuppressive molecules, including CXCR4, PD-L1, and VEGFA. Expression differences for cell surface and secreted proteins were confirmed in patient-derived tumor lines and functional relationships between altered chemokine expression and immune cell infiltration was investigated. Our data provide novel insights into the immune contexture of MAPK driven LGGs and suggest MAPK driven gliomas with biallelic inactivation of CDKN2A may be particularly vulnerable to immunotherapeutic modulation


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Amanda W. K. AuYeung ◽  
Robert C. Mould ◽  
Ashley A. Stegelmeier ◽  
Jacob P. van Vloten ◽  
Khalil Karimi ◽  
...  

AbstractVaccination can prevent viral infections via virus-specific T cells, among other mechanisms. A goal of oncolytic virotherapy is replication of oncolytic viruses (OVs) in tumors, so pre-existing T cell immunity against an OV-encoded transgene would seem counterproductive. We developed a treatment for melanomas by pre-vaccinating against an oncolytic vesicular stomatitis virus (VSV)-encoded tumor antigen. Surprisingly, when the VSV-vectored booster vaccine was administered at the peak of the primary effector T cell response, oncolysis was not abrogated. We sought to determine how oncolysis was retained during a robust T cell response against the VSV-encoded transgene product. A murine melanoma model was used to identify two mechanisms that enable this phenomenon. First, tumor-infiltrating T cells had reduced cytopathic potential due to immunosuppression. Second, virus-induced lymphopenia acutely removed virus-specific T cells from tumors. These mechanisms provide a window of opportunity for replication of oncolytic VSV and rationale for a paradigm change in oncolytic virotherapy, whereby immune responses could be intentionally induced against a VSV-encoded melanoma-associated antigen to improve safety without abrogating oncolysis.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xiaohui Wang ◽  
Xiang Lin ◽  
Zihan Zheng ◽  
Bingtai Lu ◽  
Jun Wang ◽  
...  

AbstractInnate immunity is important for host defense by eliciting rapid anti-viral responses and bridging adaptive immunity. Here, we show that endogenous lipids released from virus-infected host cells activate lung γδ T cells to produce interleukin 17 A (IL-17A) for early protection against H1N1 influenza infection. During infection, the lung γδ T cell pool is constantly supplemented by thymic output, with recent emigrants infiltrating into the lung parenchyma and airway to acquire tissue-resident feature. Single-cell studies identify IL-17A-producing γδ T (Tγδ17) cells with a phenotype of TCRγδhiCD3hiAQP3hiCXCR6hi in both infected mice and patients with pneumonia. Mechanistically, host cell-released lipids during viral infection are presented by lung infiltrating CD1d+ B-1a cells to activate IL-17A production in γδ T cells via γδTCR-mediated IRF4-dependent transcription. Reduced IL-17A production in γδ T cells is detected in mice either lacking B-1a cells or with ablated CD1d in B cells. Our findings identify a local host-immune crosstalk and define important cellular and molecular mediators for early innate defense against lung viral infection.


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