Cell-mediated Research Articles

T cell responses to repeated SARS-CoV-2 vaccination and breakthrough infections in patients on TNF inhibitor treatment: a prospective cohort study

Understanding cellular responses to SARS-CoV-2 immunisations is important for informing vaccine recommendations in patients with inflammatory bowel disease (IBD) and other vulnerable patients on immunosuppressive therapies. This study investigated the magnitude and quality of T cell responses after multiple SARS-CoV-2 vaccine doses and COVID-19 breakthrough infection. This prospective, observational study included patients with IBD and arthritis on tumour necrosis factor inhibitors (TNFi) receiving up to four SARS-CoV-2 vaccine doses. T cell responses to SARS-CoV-2 peptides were measured by flow cytometry before and 2-4 weeks after vaccinations and breakthrough infection to assess the frequency and polyfunctionality of responding cells, along with receptor-binding domain (anti-RBD) antibodies. Between March 2, 2021, and December 20, 2022, 143 patients (118 IBD, 25 arthritis) and 73 healthy controls were included. In patients with either IBD or arthritis, humoral immunity was attenuated compared to healthy controls (median anti-RBD levels 3391 vs. 6280 BAU/ml, p=0.008) after three SARS-CoV-2 vaccine doses. Patients with IBD had comparable quantities (median CD4 0.11% vs. 0.11%, p=0.26, CD8 0.031% vs. 0.047%, p=0.33) and quality (polyfunctionality score: 0.403 vs. 0.371, p=0.39; 0.105 vs. 0.101, p=0.87) of spike-specific T cells to healthy controls. Patients with arthritis had lower frequencies but comparable quality of responding T cells to controls. Breakthrough infection increased spike-specific CD8 T cell quality and T cell responses against non-spike peptides. Patients with IBD on TNFi have T cell responses comparable to healthy controls despite attenuated humoral responses following three vaccine doses. Repeated vaccination and breakthrough infection increased the quality of T cell responses. Our study adds evidence that, in the absence of other risk factors, this group may in future be able to follow the general recommendations for COVID-19 vaccines. South-Eastern Norway Regional Health Authority, Coalition for Epidemic Preparedness Innovations (CEPI), Norwegian Institute of Public Health, Akershus University Hospital, Diakonhjemmet Hospital.

Rapid Autopsy to Define Dendritic Cell Spatial Distribution and T Cell Association in Lung Adenocarcinoma.

Immunotherapy response is associated with the presence of conventional dendritic cells (cDCs). cDC type 1 (cDC1) is critically important for CD8+ T cell activation, cDC type 2 (cDC2) regulates CD4+ T cell responses, and mature regulatory cDCs may dampen T cell responses in the tumor microenvironment (TME). However, we lack a clear understanding of cDC distribution in the human TME, cDC prevalence in metastatic sites, and cDC differences in early- versus late-stage disease. Rapid autopsy specimens of 10 patients with lung adenocarcinoma were evaluated to detect cDCs and immune cells via multiplex immunofluorescence using 18 markers and 42 tumors. First, we found that T cells, cDC1, and cDC2 were confined to stroma, whereas mature regulatory DCs were enriched in tumor, suggesting unique localization-specific functions. Second, lung and lymph node tumors were more enriched in T cells and cDCs than liver tumors, underscoring differences in the TME of metastatic sites. Third, although the proportion of T cells and cDC1 did not differ in different stages, an increase in the proportion of cDC2 and macrophages in late stage suggests potential differences in regulation of T cell responses in different stages. Collectively, these findings provide new, to our knowledge, insights into cDC biology in human cancer that may have important therapeutic implications.

TLR3/TRIF and MAVS Signaling Is Essential in Regulating Mucosal T Cell Responses during Rotavirus Infection.

The functions of the natural dsRNA sensors TLR3 (TRIF) and RIG-I (MAVS) are crucial during viral challenge and have not been accurately clarified in adaptive immune responses to rotavirus (RV) infection. In this study, we found that RV infection caused severe pathological damage to the small intestine of TLR3-/- and TRIF-/- mice. Our data found that dendritic cells from TLR3-/- and TRIF-/- mice had impaired Ag presentation to the RV and attenuated initiation of T cells upon viral infection. These attenuated functions resulted in impaired CD4+ T and CD8+ T function in mice lacking TLR3-TRIF signaling postinfection. Additionally, attenuated proliferative capacity of T cells from TLR3-/- and TRIF-/- mice was observed. Subsequently, we observed a significant reduction in the absolute number of memory T cells in the spleen and mesenteric lymph node (MLN) of TRIF-/- recipient mice following RV infection in a bone marrow chimeric model. Furthermore, there was reduced migration of type 2 classical dendritic cells from the intestine to MLNs after RV infection in TLR3-/- and TRIF-/- mice. Notably, RV infection resulted in attenuated killing of spleen and MLN tissues in TRIF-/- and MAVS-/- mice. Finally, we demonstrated that RV infection promoted apoptosis of CD8+ T cells in TRIF-/- and TLR3-/-MAVS-/- mice. Taken together, our findings highlight an important mechanism of TLR3 signaling through TRIF in mucosal T cell responses to RV and lay the foundation for the development of a novel vaccine.

Within-subject Comparison Reveals Enhanced Satellite Cell Response To Eccentric Overload During Heavy Resistance Exercise

Within-subject Comparison Reveals Enhanced Satellite Cell Response To Eccentric Overload During Heavy Resistance Exercise

Post-exercise T Cell Response Influenced By Absolute Intensity In Resistance Exercise But Not Cardiorespiratory Exercise

Post-exercise T Cell Response Influenced By Absolute Intensity In Resistance Exercise But Not Cardiorespiratory Exercise

Nonreducing Sugar Scaffold Enables the Development of Immunomodulatory TLR4-specific LPS Mimetics with Picomolar Potency.

Innate immune defense mechanisms against infection and cancer encompass the modulation of pattern recognition receptor (PRR)-mediated inflammation, including upregulation of various transcription factors and the activation of pro-inflammatory pathways important for immune surveillance. Dysfunction of PRRs-mediated signaling has been implicated in cancer and autoimmune diseases, while the overactivation of PRRs-driven responses during infection can lead to devastating consequences such as acute lung injury or sepsis. We used crystal structure-based design to develop immunomodulatory lipopolysaccharide (LPS) mimetics targeting one of the ubiquitous PRRs, Toll-like Receptor 4 (TLR4). Taking advantage of an exo-anomeric conformation and specific molecular shape of synthetic nonreducing β,β-diglucosamine, which was investigated by NMR, we developed two sets of lipid A mimicking glycolipids capable of either potently activating innate immune responses or inhibiting pro-inflammatory signaling. Stereoselective 1,1'-glycosylation towards fully orthogonally protected nonreducing GlcNβ(1↔1')βGlcN followed by stepwise assembly of differently functionalised phosphorylated glycolipids provided biologically active molecules that were evaluated for their ability to trigger or to inhibit cellular innate immune responses. Two LPS mimetics, identified as potent TLR4-specific inducers of the intracellular signaling pathways, serve as vaccine adjuvant- and immunotherapy candidates, while anionic glycolipids with TLR4-inhibitory potential hold therapeutic promise for the management of acute or chronic inflammation.

Abstract C156: Examining the role of T cell responses in colorectal cancer sex disparities

Abstract C156: Examining the role of T cell responses in colorectal cancer sex disparities

Favourable humoral but reduced cellular immune response to COVID-19 mRNA BNT162b2 vaccine in patients with childhood-onset systemic lupus erythematosus

ObjectiveTo evaluate both humoral and cellular immune responses to the COVID-19 messenger RNA (mRNA; BNT162b2) vaccine in patients with childhood-onset SLE (cSLE) compared with healthy controls and patient controls (kidney...

What's in a name: the multifaceted function of DNA‐ and RNA‐binding proteins in T cell responses

What's in a name: the multifaceted function of <scp>DNA</scp>‐ and <scp>RNA</scp>‐binding proteins in T cell responses

TRIM35 triggers cardiac remodeling by regulating SLC7A5-mediated amino acid transport and mTORC1 activation in fibroblasts

BackgroundCardiac maladaptive remodeling is one of the leading causes of heart failure with highly complicated pathogeneses. The E3 ligase tripartite motif containing 35 (TRIM35) has been identified as a crucial regulator governing cellular growth, immune responses, and metabolism. Nonetheless, the role of TRIM35 in fibroblasts in cardiac remodeling remains elusive.MethodsHeart tissues from human donors were used to verify tissue-specific expression of TRIM35. Fibroblast-specific Trim35 gene knockout mice (Trim35cKO) were used to investigate the function of TRIM35 in fibroblasts. Cardiac function, morphology, and molecular changes in the heart tissues were analyzed after transverse aortic constriction (TAC) surgery. The mechanisms by which TRIM35 regulates fibroblast phenotypes were elucidated using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and RNA sequencing (RNA-Seq). These findings were further validated through the use of adenoviral and adeno-associated viral transfection systems, as well as the mTORC1 inhibitor Rapamycin.ResultsTRIM35 expression is primarily up-regulated in cardiac fibroblasts in both murine and human fibrotic hearts, and responds to TGF-β1 stimulation. Specific deletion of TRIM35 in cardiac fibroblasts significantly improves cardiac fibrosis and hypertrophy. Consistently, the overexpression of TRIM35 promotes fibroblast proliferation, migration, and differentiation. Through paracrine signaling, it induces hypertrophic growth of cardiomyocytes. Mechanistically, we found that TRIM35 interacts with, ubiquitinates, and up-regulates the amino acid transporter SLC7A5, which enhances amino acid transport and activates the mTORC1 signaling pathway. Furthermore, overexpression of SLC7A5 significantly reverses the reduced cardiac fibrosis and hypertrophy caused by conditional knockout of TRIM35.ConclusionOur findings demonstrate a novel role of fibroblast-TRIM35 in cardiac remodeling and uncover the mechanism underlying SLC7A5-mediated amino acid transport and mTORC1 activation. These results provide a potential novel therapeutic target for treating cardiac remodeling.

Interference without interferon: interferon-independent induction of interferon-stimulated genes and its role in cellular innate immunity

ABSTRACT Interferons (IFNs) are multifaceted proteins that play pivotal roles in orchestrating robust antiviral immune responses and modulating the intricate landscape of host immunity. The major signaling pathway activated by IFNs is the JAK/STAT (Janus kinase/signal transducer and activator of transcription) pathway, which leads to the transcription of a battery of genes, collectively known as IFN-stimulated genes (ISGs). While the well-established role of IFNs in coordinating the innate immune response against viral infections is widely acknowledged, recent years have provided a more distinct comprehension of the functional significance attributed to non-canonical, IFN-independent induction of ISGs. In this review, we summarize the non-conventional signaling pathways of ISG induction. These alternative pathways offer new avenues for developing antiviral strategies or immunomodulation in various diseases.

Comparative Analysis of the Aspergillus fumigatus Cell Wall Modification and Ensuing Human Dendritic Cell Responses by β-(1,3)-Glucan Synthase Inhibitors—Caspofungin and Enfumafungin

Comparative Analysis of the Aspergillus fumigatus Cell Wall Modification and Ensuing Human Dendritic Cell Responses by β-(1,3)-Glucan Synthase Inhibitors—Caspofungin and Enfumafungin

Subset-specific mitochondrial stress and DNA damage shape T cell responses to fever and inflammation

Heat is a cardinal feature of inflammation, yet its impacts on immune cells remain uncertain. We show that moderate-grade fever temperatures (39°C) increased murine CD4 T cell metabolism, proliferation, and inflammatory effector activity while decreasing regulatory T cell suppressive capacity. However, heat-exposed T helper 1 (T H 1) cells selectively developed mitochondrial stress and DNA damage that activated Trp53 and stimulator of interferon genes pathways. Although many T H 1 cells subjected to such temperatures died, surviving T H 1 cells exhibited increased mitochondrial mass and enhanced activity. Electron transport chain complex 1 (ETC1) was rapidly impaired under fever-range temperatures, a phenomenon that was specifically detrimental to T H 1 cells. T H 1 cells with elevated DNA damage and ETC1 signatures were also detected in human chronic inflammation. Thus, fever-relevant temperatures disrupt ETC1 to selectively drive apoptosis or adaptation of T H 1 cells to maintain genomic integrity and enhance effector functions.

Effectiveness and Safety of mRNA Vaccines in the Therapy of Glioblastoma

Glioblastoma (GBM) is the most common and most malignant primary brain tumor, presenting significant treatment challenges due to its heterogeneity, invasiveness, and resistance to conventional therapies. Despite aggressive treatment protocols, the prognosis remains poor, with a median survival time of approximately 15 months. Recent advancements in mRNA vaccine technology, particularly the development of lipid nanoparticles (LNPs), have revitalized interest in mRNA-based therapies. These vaccines offer unique advantages, including rapid production, personalization based on tumor-specific mutations, and a strong induction of both humoral and cellular immune responses. mRNA vaccines have demonstrated potential in preclinical models, showing significant tumor regression and improved survival rates. Early-phase clinical trials have indicated that mRNA vaccines are safe and can induce robust immune responses in GBM patients. Combining mRNA vaccines with other immunotherapeutic approaches, such as checkpoint inhibitors, has shown synergistic effects, further enhancing their efficacy. However, challenges such as optimizing delivery systems and overcoming the immunosuppressive tumor microenvironment remain. Future research should focus on addressing these challenges and exploring combination therapies to maximize therapeutic benefits. Large-scale, randomized clinical trials are essential to validate the efficacy and safety of mRNA vaccines in GBM therapy. The potential to reshape the tumor microenvironment and establish long-term immunological memory underscores the transformative potential of mRNA vaccines in cancer immunotherapy.

TOPAS-Tissue: A Framework for the Simulation of the Biological Response to Ionizing Radiation at the Multi-Cellular Level

This work aims to develop and validate a framework for the multiscale simulation of the biological response to ionizing radiation in a population of cells forming a tissue. We present TOPAS-Tissue, a framework to allow coupling two Monte Carlo (MC) codes: TOPAS with the TOPAS-nBio extension, capable of handling the track-structure simulation and subsequent chemistry, and CompuCell3D, an agent-based model simulator for biological and environmental behavior of a population of cells. We verified the implementation by simulating the experimental conditions for a clonogenic survival assay of a 2-D PC-3 cell culture model (10 cells in 10,000 µm2) irradiated by MV X-rays at several absorbed dose values from 0–8 Gy. The simulation considered cell growth and division, irradiation, DSB induction, DNA repair, and cellular response. The survival was obtained by counting the number of colonies, defined as a surviving primary (or seeded) cell with progeny, at 2.7 simulated days after irradiation. DNA repair was simulated with an MC implementation of the two-lesion kinetic model and the cell response with a p53 protein-pulse model. The simulated survival curve followed the theoretical linear–quadratic response with dose. The fitted coefficients α = 0.280 ± 0.025/Gy and β = 0.042 ± 0.006/Gy2 agreed with published experimental data within two standard deviations. TOPAS-Tissue extends previous works by simulating in an end-to-end way the effects of radiation in a cell population, from irradiation and DNA damage leading to the cell fate. In conclusion, TOPAS-Tissue offers an extensible all-in-one simulation framework that successfully couples Compucell3D and TOPAS for multiscale simulation of the biological response to radiation.

High expression of PAX8-AS1 correlates with poor prognosis and response to fluorouracil-based chemotherapy in stage II colon cancer

Decisions regarding adjuvant therapy in patients with stage II colon cancer remains controversial and challenging. We aimed to determine novel biomarkers that help to predict relapse free survival (RFS) and identify a subset of patients with stage II colon cancer who could gain survival benefits from adjuvant chemotherapy. Public microarray datasets of stage II colon cancer samples were extracted from Gene Expression Omnibus database. Global gene expression changes were then analyzed between the paired early relapse and long-term survival group to identify the differentially expressed mRNAs and lncRNAs. Based on Lasso Cox regression modeling analysis, a total of 30 mRNAs and 2 lncRNAs were finally identified. With specific formula, stage II patients in training and validation sets were divided into low and risk groups with significantly different RFS. PAX8-AS1 is the novel lncRNA which showed the highest upregulation in early relapse group. Patients with high PAX8-AS1 expression level showed notably poorer RFS in both meta GEO cohort (P = 0.04, Figure 4B) and FUSCC cohort (P < 0.001, Figure 4C). Among the stage II patients with high PAX8-AS1 level, administration of fluorouracil-based adjuvant chemotherapy provided a substantial improvement in RFS (P = 0.002, Figure 3C). Further mechanistic study unveiled that PAX8-AS1 increases the response of CRC cells to chemotherapy in vitro and in vivo by maintaining the mRNA stability of PAX8. In conclusion, PAX8-AS1 as a novel and reliable biomarker for predicting prognosis and identification of patients with stage II disease who could gain survival benefit from fluorouracil-based adjuvant chemotherapy.

Hydrodynamic hovering of swimming bacteria above surfaces

Flagellated bacteria are hydrodynamically attracted to rigid walls, yet past work shows a “hovering” state where they swim stably at a finite height above surfaces. We use numerics and theory to reveal the physical origin of hovering. Simulations first show that hovering requires an elongated cell body and results from a tilt away from the wall. Theoretical models then identify two essential asymmetries: the response of width-asymmetric cells to active flows created by length-asymmetric cells. A minimal model reconciles near- and far-field hydrodynamics, capturing all key features of hovering. Published by the American Physical Society 2024

PM2.5 Exposure Aggravates Inflammatory Response and Mucus Production in 16HBE Cells through Inducing Oxidative Stress and RAGE Expression.

Particulate matter 2.5 (PM2.5)-induced oxidative stress has been extensively proposed as a pivotal event in lung diseases. Receptor for advanced glycation end-products (RAGE) is a receptor of pro-inflammatory ligands that has been supported to be implied in the progression of multiple lung diseases. This study attempts to delineate the specific effects of PM2.5 on human bronchial epithelial 16HBE cells in vitro and figure out whether PM2.5 functions via mediating oxidative stress and RAGE. In PM2.5-challenged 16HBE cells, MTT assay detected cell viability. ELISA estimated inflammatory levels. Flow cytometry analysis measured ROS activity and related assay kits examined oxidative stress levels. Western blot tested nuclear factor E2-related factor 2 (Nrf2), RAGE, β-catenin, and mucin 5AC (MUC5AC) expression. Immunofluorescence staining evaluated nuclear translocation of β-catenin. It was noticed that PM2.5 exposure exacerbated inflammatory response, oxidative stress, and mucus production. Additionally, PM2.5 elevated RAGE expression while declined Nrf2 expression as well as stimulated the nuclear translocation of β-catenin. Furthermore, RAGE inhibition or nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor VAS2870 mitigated inflammatory response, oxidative stress, and mucus generation in PM2.5-exposed 16HBE cells. In addition, RAGE inhibition or VAS2870 raised Nrf2 expression, reduced RAGE expression, and hampered β-catenin nuclear translocation. Briefly, PM2.5 might act as a leading driver of inflammatory response and mucus production in lung injury, the mechanism of which might be related to the activation of oxidative stress and the up-regulation of RAGE.

Tissue Kallikrein-1 Suppresses Type I Interferon Responses and Reduces Depressive-Like Behavior in the MRL/lpr Lupus-Prone Mouse Model

Excessive production and response to Type I interferons (IFNs) is a hallmark of systemic lupus erythematosus (SLE). Neuropsychiatric lupus (NPSLE) is a common manifestation of human SLE, with major depression as the most common presentation. Clinical studies have demonstrated that IFNα can cause depressive symptoms. We have shown that the kallikrein–kinin system (KKS) [comprised of kallikreins (Klks) and bradykinins] and angiotensin-converting enzyme inhibitors suppressed Type I IFN responses in dendritic cells from lupus-prone mice and human peripheral blood mononuclear cells. Tissue Klk genes are decreased in patients with lupus, and giving exogenous Klk1 ameliorated kidney pathology in mice. We retro-orbitally administered mouse klk1 gene-carrying adenovirus in the Murphy Roths Large lymphoproliferative (MRL/lpr) lupus-prone mice at early disease onset and analyzed immune responses and depressive-like behavior. Klk1 improved depressive-like behavior, suppressed interferon-responsive genes and neuroinflammation, and reduced plasma IFNα levels and proinflammatory cytokines. Klk1 also reduced IFNAR1 and JAK1 protein expression, important upstream molecules in Type I IFN signaling. Klk1 reduced bradykinin B1 receptor expression, which is known to induce proinflammatory response. Together, these findings suggest that Klk1 may be a potential therapeutic candidate to control IFNα production/responses and other inflammatory responses in SLE and NPSLE.

Characterization of Cellular Immune System at Different Ages in Water Buffalo (Bubalus bubalis)

In recent years, there has been an increased interest in understanding the immune system of the water buffalo due to the increased economic impact of this species. The study aimed to perform an in-depth evaluation of lymphoid and myeloid cells in water buffalo of different ages. We assess three multicolor panels of antibodies to evaluate by flow cytometry the percentage of the CD3+ CD4+, CD8+, and γδ T lymphocytes; CD79+ and CD21+ B lymphocytes; monocytes and cM, intM, and ncMsubsets; NK cells, granulocytes, and peripheral blood mononuclear cell (PBMC). Seventy-eight animals from three different farms were divided into three groups by age (26 in each group): 80-100 days old calves, 16-18 months old heifers, and 4-6 years old cows. Significant differences by Kruskal-Wallis test were found between age groups in the percentage of CD4+, CD8+, γδ T lymphocytes, NK cells (P=0.0001), total monocytes (P=0.0008), granulocytes (P=0.0358) and PBMC (P=0.0056). Between the farms, the adult animals showed differences in the percentage ofCD3+ (P=0.0152), CD4+ (P=0.0047), CD8+ (P=0.0019), CD4:CD8 ratio (P=0.0033) and γδ (P=0.0013) T lymphocytes; CD21+ B lymphocytes (P=0.0007);total monocytes (P=0.0100), cM and ncM subsets (P=0.0320;P=0.0252), granulocytes (P=0.0030) and PBMC (P=0.0120). The calves showed significant differences in CD79+ and CD21+ B lymphocytes (P=0.0141; P=0.0049), total monocytes (P=0.0010), cM, intM and ncM subsets (P=0.0335; P=0.0499; P=0.0065). The heifers group in CD21+ B subset (P=0.0439).In summary, this study provides the composition of lymphoid and myeloid cells in this species for the first time, highlighting large differences between age groups and between different herds.