Investigation of Signaling in Primary Populations of Human Senescent T Cells.

Mitogen-activated protein kinases, a family of three stress-related kinases, the Erks and Jnks and p38s, are activated by three-layer transphosphorylation cascades and are important for the activation, differentiation, and effector functions of lymphocytes. Recent studies on the aged immune systems from both humans and mice have uncovered a different mode of MAPK signaling that is independent of canonical activation cascades and instead occurs through simultaneous self-phosphorylation reactions within the sestrin-MAPK activation complex (sMAC), an immune-inhibitory complex not previously observed. In this chapter, we discuss methodologies to study these pathways at the population and single cell level, which allows rejuvenating immune cell differentiation and fate.

Virologic Failure, Clinical Characteristics, and Common Viral Mutations in HIV Patients From Southwestern Colombia: A Nested Case-Control Study.

Introduction Virologic failure due to antiretroviral drug resistance is a threat to efforts to control the human immunodeficiency virus (HIV) epidemic. Understanding the factors that influence the genetic and clinical expression of drug resistance is fundamental for infection control. Methods A nested case-control study was conducted on a cohort of adult HIV patients between 2016 and 2022. The cases were defined as patients with a confirmed diagnosis of virologic failure due to drug resistance, as indicated by a viral genotype result. The control group consisted of patients who had not experienced virologic failure or undergone any documented changes to their antiretroviral treatment. The incidence of virologic failure over a defined period was calculated. The characteristics of each group were documented in frequency tables and measures of central tendency. To identify risk factors, multiple logistic regression models were employed, and post hoc tests were conducted. All calculations were performed with 95% confidence intervals, and p-values less than 0.05 were considered significant. Results The incidence of virologic failure over the seven-year study period was 9.2% (95% CI: 7.5-11.2%). Low CD4 T-lymphocyte count (≤200 cells/mm³) at diagnosis (adjOR 14.2, 95% CI: 3.1-64.5), history of opportunistic infections (adjOR 3.5, 95% CI: 1.9-6.4), and late enrollment into an HIV program after diagnosis (>1 year) (adjOR 9.2, 95% CI: 3.8-22.2) were identified as independent predictors of virologic failure. The drugs with the highest rates of resistance were nevirapine (84.6%), efavirenz (82.4%), emtricitabine (81.3%), lamivudine (81.3%), and atazanavir (6.6%). The most prevalent major mutations identified were K103N, M184V, and M46I/M. Approximately 50% of the secondary mutations were identified in protease regions. Conclusions The incidence of virologic failure was low in the study population. The identified risk characteristics allow for the prediction of the profile of patients susceptible to failure and for the early optimization of treatment regimens.

Peripheral blood immunophenotypic diversity in patients with rheumatoid arthritis and its impact on therapeutic responsiveness.

OBJECTIVE: Considering the diverse aetiologies and immunodysregulatory statuses observed in each patient with rheumatoid arthritis (RA), stratification based on peripheral blood immunophenotyping holds the potential to enhance therapeutic responses to molecular targeted therapies, biological/targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs). METHODS: Immunophenotype analysis was conducted on a cohort of over 500 b/tsDMARDs-naïve patients using flow cytometry. Patients with RA were stratified based on their immunophenotypes, and the treatment response to each targeted therapy was evaluated. Validation was performed using an additional cohort of 183 b/tsDMARDs-naïve patients with RA. RESULTS: Patients with RA were stratified into five clusters, two of which exhibited distinct RA phenotypes compared with controls, characterised by significant increases in CD4+ effector memory T cells re-expressing CD45RA. Notably, the effectiveness of different b/tsDMARDs varied across clusters. The group using promising b/tsDMARDs was labelled as 'expected' whereas the 'non-expected' group comprised those using others. The expected group outperformed the non-expected group with higher 26-week remission rates (39.9% vs 24.6%, p=0.0004) and low disease activity achievement (80.8% vs 60.2%, p<0.0001). Trajectory analysis showed the non-expected group's 26-week disease activity was influenced by Clinical Disease Activity Index at baseline unlike the expected group. Additionally, different molecular targeted therapies influenced the proportions of each immune cell subset variably. To validate, immunophenotyping was performed on a validation cohort. When 183 cases were grouped based on their b/tsDMARDs usage into expected/non-expected groups, the expected group had a higher remission rate (p=0.0021), further confirming the observed trend. CONCLUSION: Our findings offer valuable insights into the diversity of RA and potential therapeutic strategies grounded in the molecular underpinnings.

Prognostic value of atypical B cells in breast cancer.

The impact of tumor-infiltrating B cells on breast cancer (BRCA) outcomes remains poorly understood. Recent findings from Yang et al. identify an atypical, clonally expanded population of activated Fc receptor-like 4 (FCRL4)+ B cells that is associated with improved overall survival in patients affected by various tumor types, including BRCA.

Different genome-wide DNA methylation patterns in CD4+ T lymphocytes and CD14+ monocytes characterize relapse and remission of multiple sclerosis: Focus on GNAS.

BACKGROUND: Relapsing-remitting multiple sclerosis (RRMS) is a most common form of multiple sclerosis in which periods of neurological worsening are followed by periods of clinical remission. RRMS relapses are caused by an acute autoimmune inflammatory process, which can occur in any area of the central nervous system. Although development of exacerbation cannot yet be accurately predicted, various external factors are known to affect its risk. These factors may trigger the pathological process through epigenetic mechanisms of gene expression regulation, first of all, through changes in DNA methylation. METHODS: In the present work, we for the first time analyzed genome-wide DNA methylation patterns in CD4+ T lymphocytes and CD14+ monocytes of the same RRMS patients in relapse and remission. The effects of the differential methylation on gene expression were studied using qPCR. RESULTS: We found 743 differentially methylated CpG positions (DMPs) in CD4+ cells and only 113 DMPs in CD14+ cells. They were mostly hypermethylated in RRMS relapse in both cell populations. However, the proportion of hypermethylated DMPs (as well as DMPs located within or in close proximity to CpG islands) was significantly higher in CD4+ T lymphocytes. In CD4+ and CD14+ cells we identified 469 and 67 DMP-containing genes, respectively; 25 of them were common for two cell populations. When we conducted a search for differentially methylated genomic regions (DMRs), we found a CD4+ specific DMR hypermethylated in RRMS relapse (adj. p = 0.03) within the imprinted GNAS locus. Total level of the protein-coding GNAS transcripts in CD4+ T cells decreased significantly in the row from healthy control to RRMS remission and then to RRMS relapse (adj. p = 3.1 × 10-7 and 0.011, respectively). CONCLUSION: Our findings suggest that the epigenetic mechanism of DNA methylation in immune cells contributes to the development of RRMS relapse. Further studies are now required to validate these results and shed light on the molecular mechanisms underlying the observed GNAS methylation and expression changes.

Differential lipid signaling from CD4+ and CD8+ T cells contributes to type 1 diabetes development.

Introduction: We reported that Ca2+-independent phospholipase A2ß (iPLA2ß)-derived lipids (iDLs) contribute to type 1 diabetes (T1D) onset. As CD4+ and CD8+ T cells are critical in promoting ß-cell death, we tested the hypothesis that iDL signaling from these cells participates in T1D development. Methods: CD4+ and CD8+ T cells from wild-type non-obese diabetic (NOD) and NOD.iPLA2ß+/- (NOD.HET) mice were administered in different combinations to immunodeficient NOD.scid. Results: In mice receiving only NOD T cells, T1D onset was rapid (5 weeks), incidence 100% by 20 weeks, and islets absent. In contrast, onset was delayed 1 week and incidence reduced 40%-50% in mice receiving combinations that included NOD.HET T cells. Consistently, islets from these non-diabetic mice were devoid of infiltrate and contained insulin-positive ß-cells. Reduced iPLA2ß led to decreased production of proinflammatory lipids from CD4+ T cells including prostaglandins and dihydroxyeicosatrienoic acids (DHETs), products of soluble epoxide hydrolase (sEH), and inhibition of their signaling decreased (by 82%) IFNγ+CD4+ cells abundance. However, only DHETs production was reduced from CD8+ T cells and was accompanied by decreases in sEH and granzyme B. Discussion: These findings suggest that differential select iDL signaling in CD4+ and CD8+ T cells contributes to T1D development, and that therapeutics targeting such signaling might be considered to counter T1D.

ADIPOPHILIN PEPTIDE (ADPH 129-137) IS NOT A TARGET ANTIGEN FOR CD8+ T-CELLS IN PATIENTS WITH OBESITY.

Context: In obesity, the infiltration of leukocytes into adipose tissue seems to play a key role in the development of inflammation and insulin resistance. Over-expression of adipophilin (ADPH) in adipose tissue, a protein which regulates lipid droplet structure and formation, has been reported in some studies. Objective: To investigate the role of ADPH 129-137 as a target for CD8+ T-cells in PBMCs of patients with obesity. Subjects and Methods: PBMCs were obtained from 9 non-diabetic obese patients and 11 healthy subjects expressing the HLA-A0201 molecule. The ELISPOT assay used to monitor the presence of IFN-γ producing CD8+ T-cells against a HLA class I-restricted epitope derived from Adipophilin (ADPH 129-137) and two control peptides: Flu MP58-66 and Melan-A27-35. Results: The outcomes showed no significant difference between patient group and healthy donors in response to ADPH 129-137. Conclusion: These results demonstrated that ADPH 129-137 peptide possibly does not act as an autoantigen in patients with obesity.

The impact of gliomas on the normal brain microenvironment: a pilot study.

Gliomas are malignant tumors of neuronal support cells within the central nervous system (CNS) and are characterized by poor overall prognoses and limited treatment options due to their infiltrative growth patterns. The neural tumor microenvironment, composed of benign neurons, neuroglia, endothelial cells, and intravascular white blood cells, is a target-rich site for potential chemotherapeutic agents. This study assessed cell proliferation rates, white blood cell components, and a limited number of nuclear, cytoplasmic, and membrane markers using immunohistochemistry (IHC) assays on formalin-fixed and paraffin-embedded benign and glial tumor tissue samples from the CNS. It was observed that glioma tissues had increased rates of glial cell proliferation and significant increases in the number of observed T-lymphocytes and granulocytes but decreased expression of markers Somatostatin receptor 2 (SSTR2), L1 cell adhesion molecule (L1CAM), and GATA binding protein 3 (GATA3) when compared to benign tissue samples. Understanding the lack of protein expression and population expansion potential of the glioma microenvironment in greater detail could help identify valuable therapeutic target combinations for future treatments.

IFNγ induces epithelial reprogramming driving CXCL11-mediated T cell migration.

The cytokine interferon-gamma (IFNγ) plays a multifaceted role in intestinal immune responses ranging from anti- to pro-inflammatory depending on the setting. Here, using a 3D co-culture system based on human intestinal epithelial organoids, we explore the capacity of IFNγ-exposure to reprogram intestinal epithelia and thereby directly modulate lymphocyte responses. IFNγ treatment of organoids led to transcriptional reprogramming, marked by a switch to a pro-inflammatory gene expression profile, including transcriptional upregulation of the chemokines CXCL9, CXCL10, and CXCL11. Proteomic analysis of organoid-conditioned medium post-treatment confirmed chemokine secretion. IFNγ-treatment of organoids led to enhanced T cell migration in a CXCL11-dependent manner without affecting T cell activation status. Taken together, our results suggest a specific role for CXCL11 in T cell recruitment that could be targeted to prevent T cell trafficking to the inflamed intestine.

The Influence of Metabolites of Microorganisms of the Genus Bacillus from Permafrost Rocks on T Lymphocyte Differentiation.

We studied the influence of metabolites of permafrost microorganisms obtained at different temperature incubation conditions on activity of differentiation of regulatory (Treg) and effector T lymphocytes. It was found that the effect of metabolites is largely regulated by their type that depends on the temperature of production ("cold" at 5°C, "medium temperature" at 22°C, and "warm" at 37°C). The studied metabolites influenced the differentiation of Tregs (CD4+CD25hiCD127-) and the expression of markers of early (CD69), middle (CD25), and late (HLA DR) activation of CD4+ and CD8+ T lymphocytes. In the case of "cold" metabolites, the increase in Treg levels was associated with a decrease in the intensity of CD4+ T lymphocyte differentiation, and under the influence of "warm" metabolites - with a decrease in the activity of CD8+ T lymphocyte differentiation. Under the influence of "medium-temperature" metabolites, Tregs had approximately the same effect on the intensity of CD4+ and CD8+ T lymphocyte differentiation.

Glycogen nanoparticles for efficient mRNA transduction to T lymphocytes.

T lymphocyte therapies demonstrate significant promise in the treatment of cancer and infectious diseases. An efficient gene delivery system is essential for the safe and reliable introduction of exogenous genes, especially mRNA, into cells to achieve therapeutic purposes. Commercial transfection reagents are suitable for the transduction of plasmids to adherent cells, whereas they are ineffective for suspension cells such as T lymphocytes and for unstable mRNA. Moreover, the cytotoxicity of transfection reagents themselves constitutes an impediment to their application. The challenge of mRNA transduction to T lymphocytes with high efficiency is notably formidable. An innovative transfection strategy is urgently needed. In this study, we synthesized aminated glycogen (AGly) nanoparticles as gene vectors, encapsulating mRNA to facilitate the efficient transfection of T lymphocytes. Compared to commercial transfection reagent polyethylenimine (PEI), the AGly demonstrated favorable biocompatibility. The positive charge provided AGly with pH buffering ability and mRNA-binding capacity. AGly formed stable nanoparticles with mRNA, which were readily internalized by suspension cells and enhanced the cellular uptake of mRNA. In the T lymphocyte model cell lines (Jurkat cells and HuT 78 cells), AGly demonstrated superior transfection efficiency than that of PEI. Consequently, AGly can emerge as a viable mRNA vector for the efficient transfection of T lymphocytes whilst circumventing the issue of cytotoxicity. The AGly designed in this study provides a novel concept for the exploitation of transfection reagents and proposes a promising methodology for the proficient transfection of T lymphocytes which may significantly contribute to the treatment of cancer and other complex diseases.

The Interactions of T Cells with Myeloid-Derived Suppressor Cells in Peripheral Blood Stem Cell Grafts.

The interaction of myeloid-derived suppressor cells (MDSCs) with T cells within G-CSF-mobilized peripheral blood stem cell (PBSC) grafts in patients undergoing autologous or allogeneic hematopoietic stem cell transplantation remains to be elucidated. Through studying allo- and auto-PBSC grafts, we observed grafts containing large numbers of T cells and MDSCs with intergraft variability in their percentage and number. T cells from autologous grafts compared to allografts expressed relative higher percentages of inhibitory receptors PD-1, CTLA-4, TIM-3, LAG-3, TIGIT and BTLA. Autograft T cells had decreased cell proliferation and IFN-γ secretion, which supported the possible presence of T cell exhaustion. On the contrary, graft monocytic MDSCs (M-MDSCs) expressed multiple inhibitory receptor ligands, including PD-L1, CD86, Galectin-9, HVEM and CD155. The expression of inhibitory receptor ligands on M-MDSCs was correlated with their corresponding inhibitory receptors on T cells in the grafts. Isolated M-MDSCs had the ability to suppress T cell proliferation and IFN-γ secretion and/or promote Treg expansion. Blocking the PD-L1-PD-1 signaling pathway partially reversed the functions of M-MDSCs. Taken together, our data indicated that T cells and M-MDSCs in PBSC grafts express complementary inhibitory receptor-ligand pairing, which may impact the quality of immune recovery and clinical outcome post transplantation.

Gemcitabine, carboplatin, and Epstein-Barr virus-specific autologous cytotoxic T lymphocytes for recurrent or metastatic nasopharyngeal carcinoma: VANCE, an international randomized phase III trial.

BACKGROUND: Epstein-Barr virus-specific cytotoxic T lymphocyte (EBV-CTL) is an autologous adoptive T-cell immunotherapy generated from the blood of individuals and manufactured without genetic modification. In a previous phase II trial of locally recurrent or metastatic nasopharyngeal carcinoma (R/M NPC) patients, first-line gemcitabine and carboplatin (GC) and EBV-CTL combination demonstrated objective antitumor EBV-CTL activity and a favorable safety profile. The present study explored whether this combined first-line chemo-immunotherapy strategy would produce superior clinical efficacy and better quality of life compared with conventional chemotherapy treatment. PATIENTS AND METHODS: This multicenter, randomized, phase III trial evaluated the efficacy and safety of GC followed by EBV-CTL versus GC alone as first-line treatment of R/M NPC patients. Thirty clinical sites in Singapore, Malaysia, Taiwan, Thailand, and the USA were included. Subjects were randomized to first-line GC (four cycles) and EBV-CTL (six cycles) or GC (six cycles) in a 1 : 1 ratio. The primary outcome was overall survival (OS) and secondary outcomes included progression-free survival, objective response rate, clinical benefit rate, quality of life, and safety. CLINICALTRIALS: gov identifier: NCT02578641. RESULTS: A total of 330 subjects with NPC were enrolled. Most subjects in both treatment arms received four or more cycles of chemotherapy and most subjects in the GC + EBV-CTL group received two or more infusions of EBV-CTL. The central Good Manufacturing Practices (GMP) facility produced sufficient EBV-CTL for 94% of GC + EBV-CTL subjects. The median OS was 25.0 months in the GC + EBV-CTL group and 24.9 months in the GC group (hazard ratio = 1.19; 95% confidence interval 0.91-1.56; P = 0.194). Only one subject experienced a grade 2 serious adverse event related to EBV-CTL. CONCLUSIONS: GC + EBV-CTL in subjects with R/M NPC demonstrated a favorable safety profile but no overall improvement in OS versus chemotherapy. This is the largest adoptive T-cell therapy trial reported in solid tumors to date.

CD4+ T cells in antitumor immunity.

Advances in cancer immunotherapy have transformed cancer care and realized unprecedented responses in many patients. The growing arsenal of novel therapeutics - including immune checkpoint inhibition (ICI), adoptive T cell therapies (ACTs), and cancer vaccines - reflects the success of cancer immunotherapy. The therapeutic benefits of these treatment modalities are generally attributed to the enhanced quantity and quality of antitumor CD8+ T cell responses. Nevertheless, CD4+ T cells are now recognized to play key roles in both the priming and effector phases of the antitumor immune response. In addition to providing T cell help through co-stimulation and cytokine production, CD4+ T cells can also possess cytotoxicity either directly on MHC class II-expressing tumor cells or to other cells within the tumor microenvironment (TME). The presence of specific populations of CD4+ T cells, and their intrinsic plasticity, within the TME can represent an important determinant of clinical response to immune checkpoint inhibitors, vaccines, and chimeric antigen receptor (CAR) T cell therapies. Understanding how the antitumor functions of specific CD4+ T cell types are induced while limiting their protumorigenic attributes will enable more successful immunotherapies.

T lymphocyte-derived IFN-γ facilitates breast cancer cells to pass the blood-brain barrier: An in vitro study corroborating translational data.

The appearance of brain metastasis is the most serious complication of breast cancer with mostly fatal outcomes. To reach the brain, tumor cells need to pass the blood-brain barrier (BBB). The molecular mechanisms underlying penetration of the BBB are largely unknown. Previously we found that tumor-infiltrating T lymphocytes enhance the development of brain metastasis of estrogen receptor-negative (ER-) breast cancer. In the current study, we investigate the contribution of T lymphocytes and the IFN-γ pathway in enabling breast cancer cells to pass the in vitro BBB. CD8+ cells display the strongest stimulatory effect on breast cancer cell passage. We show that inhibition of the IFN-γ receptor in MDA-MB-231 breast cancer cells, or neutralization of soluble IFN-γ, impairs the in vitro trespassing of breast cancer cells. Importantly, we validated our findings using gene expression data of breast cancer patients. The CXCL-9,-10,-11/CXCR3 axis, dependent on IFN-γ signaling activity, was overexpressed in primary breast cancer samples of patients who developed brain metastasis. The data support a role for T-lymphocytes and the IFN-γ pathway in the formation of brain metastasis of ER-breast cancer, and offer targets to design future therapies for preventing breast cancer cells to cross the BBB.

Preliminary exploration of the expression of acetylcholinesterase in normal human T lymphocytes and leukemic Jurkat T cells.

The classic enzymatic function of acetylcholinesterase (AChE) is the hydrolysis of acetylcholine (ACh) in the neuronal synapse. However, AChE is also present in nonneuronal cells such as lymphocytes. Various studies have proposed the participation of AChE in the development of cancer. The ACHE gene produces three mRNAs (T, H and R). AChE-T encodes amphiphilic monomers, dimers, tetramers (G1 A, G2 A and G4 A) and hydrophilic tetramers (G4 H). AChE-H encodes amphiphilic monomers and dimers (G1 A and G2 A). AChE-R encodes a hydrophilic monomer (G1 H). The present study considered the differences in the mRNA expression (T, H and R) and protein levels of AChE, as well as the molecular forms of AChE, the glycosylation pattern and the enzymatic activity of AChE present in normal T lymphocytes and leukemic Jurkat E6-1 cells. The results revealed that AChE enzymatic activity was higher in normal T lymphocytes than in Jurkat cells. Normal T cells expressed AChE-H transcripts, whereas Jurkat cells expressed AChE-H and AChE-T. The molecular forms identified in normal T cells were G2 A (5.2 S) and G1 A (3.5 S), whereas those in Jurkat cells were G2 A (5.2 S), G1 A (3.5 S) and G4 H (10.6S). AChE in Jurkat cells showed altered posttranslational maturation since a decrease in the incorporation of galactose and sialic acid into its structure was observed. In conclusion, the content and composition of AChE were altered in Jurkat cells compared with those in normal T lymphocytes. The present study opened new avenues for exploring the development of novel therapeutic strategies against T-cell leukemia and for identifying potential molecular targets for the early detection of this type of cancer.

α2,6 sialylation distinguishes a novel active state in CD4+ and CD8+ cells during acute Toxoplasma gondii infection.

Toxoplasmosis is a worldwide parasitosis that is usually asymptomatic; cell-mediated immunity, particularly T cells, is a crucial mediator of the immune response against this parasite. Membrane protein expression has been studied for a long time in T lymphocytes, providing vital information to determine functional checkpoints. However, less is known about the role of post-translational modifications in T cell function. Glycosylation plays essential roles during maturation and function; particularly, sialic acid modulation is determinant for accurate T cell regulation of processes like adhesion, cell-cell communication, and apoptosis induction. Despite its importance, the role of T cell sialylation during infection remains unclear. Herein, we aimed to evaluate whether different membrane sialylation motifs are modified in T cells during acute Toxoplasma gondii infection using different lectins. To this end, BALB/c Foxp3EGFP mice were infected with T. gondii, and on days 3, 7, and 10 post-infection, splenocytes were obtained to analyze conventional (Foxp3-) CD4+ and CD8+ populations by flow cytometry. Among the different lectins used for analysis, only Sambucus nigra lectin, which detects sialic acid α2,6 linkages, revealed two distinctive populations (SNBright and SN-/Dim) after infection. Further characterization of CD4+ and CD8+ SN-/Dim lymphocytes showed that these are highly activated cells, with a TEf/EM or TCM phenotype that produce high IFN-γ levels, a previously undescribed cell state. This work demonstrates that glycan membrane analysis in T cells reveals previously overlooked functional states by evaluating only protein expression.

Quaternary ammoniums activate human dendritic cells and induce a specific T-cell response in vitro.

BACKGROUND: In many countries, neuro-muscular blocking agents (NMBAs) are the first cause of perioperative anaphylaxis. Epidemiological studies identified pholcodine, a quaternary ammonium-containing opiate as one of the sensitization sources. However, NMBA anaphylaxis exists in countries where pholcodine was unavailable, prompting the hypothesis of other sensitizing molecules, most likely quaternary ammonium compounds (QACs). Indeed, QACs are commonly used as disinfectants, antiseptics, preservatives, and detergents. Occupational exposure to QACs has been reported as a risk factor for NMBA anaphylaxis, but little is known about the sensitization mechanism and the capacity of these molecules to elicit an immune response. We aimed to establish the immunogenicity of QACs representative of the main existing chemical structures. METHODS: We measured the sensitization potential of seven QACs (two polyquaterniums, three alkyl-ammoniums and two aromatic ammoniums) by using two standard dendritic cells (DCs) models (THP-1 cell line and monocyte derived-dendritic cells). The allergenicity of the sensitizing compounds was further tested in heterologous and autologous T-cell-DC co-culture models. RESULTS: Amongst the seven molecules tested, four could modulate activation markers on DCs, and thus can be classified as chemical sensitizers (polyquaterniums-7 and -10, ethylhexadecyldimethylammonium and benzethonium). This activation was accompanied by the secretion of pro-inflammatory and maturation cytokines. Furthermore, activation by polyquaternium-7 could induce T-cell proliferation in heterologous and autologous coculture models, demonstrating that this molecule can induce a specific CD4+ T cell response. CONCLUSIONS: We provide evidence at the cellular level that some QACs can elicit an immune response, which could be in line with the hypothesis of these molecules' role in NMBA sensitization.

Apoptotic endonuclease EndoG induces alternative splicing of Caspase-2.

Caspase-2 (Casp-2) is an enzyme that regulates the development of apoptosis upon alternative splicing of its mRNA. The long form of Casp-2 (Casp-2L) promotes apoptosis while the short form (Casp-2S) has decreased enzymatic activity and inhibits the development of apoptotic processes. However, very little is known about the mechanism of Casp-2 alternative splicing. Several endonucleases are known to participate in this process. The aim of this study was to determine the role of EndoG in regulation of Casp-2 alternative splicing. Strong correlation between expression levels of EndoG and Casp-2 splice-variants was found in CD4⁺ and CD8⁺ human T lymphocytes. Such correlation increased after incubation of these cells with etoposide. Increased expression of Casp-2S was determined during EndoG over-expression in CD4⁺ T-cells, after EndoG treatment of cell cytoplasm and nuclei and after nuclei incubation with EndoG digested cell RNA. Casp-2 alternative splicing was induced by a 60-mer RNA oligonucleotide in naked nuclei and in cells after transfection. The identified long non-coding RNA of 1016 nucleotides is the precursor of the 60-mer RNA oligonucleotide. Based on the results the following mechanism has been proposed. Casp-2 pre-mRNA is transcribed from the coding DNA strand while long non-coding RNA is transcribed from the template strand of the Casp-2 gene. EndoG digests long non-coding RNA and produces the 60-mer RNA oligonucleotide complementary to the Casp-2 pre-mRNA exon 9 and intron 9 junction place. Interaction of the 60-mer RNA oligonucleotide and Casp-2 pre-mRNA causes alternative splicing.

Subpopulation dynamics of T and B lymphocytes in Sjögren's syndrome: implications for disease activity and treatment.

Sjögren's syndrome (SS) is an autoimmune disorder primarily affecting the body's exocrine glands, particularly the salivary and lacrimal glands, which lead to severe symptoms of dry eyes and mouth. The pathogenesis of SS involves the production of autoantibodies by activated immune cells, and secretion of multiple cytokines, which collectively lead to tissue damage and functional impairment. In SS, the Immune interaction among T and B cells is particularly significant. Lymphocytic infiltration in the salivary glands is predominantly composed of CD4+ T cells, whose activation cause the death of glandular epithelial cells and subsequent tissue destruction. The excessive activity of T cells contributes significantly to the disease mechanism, with helper T cells (CD4+) differentiating into various subgroups including Th1/Th2, Th17, as well as Treg, each contributing to the pathological process through distinct cytokine secretion. In patients with SS, B cells are excessively activated, leading to substantial production of autoantibodies. These antibodies can attack self-tissues, especially the lacrimal and salivary glands, causing inflammation and tissue damage. Changes in B cell subpopulations in SS patients, such as increases in plasmablasts and plasma cells, correlate positively with serum autoantibody levels and disease progression. Therapies targeting T cells and B cells are extensively researched with the aim of alleviating symptoms and improving the quality of life for patients. Understanding how these cells promote disease development through various mechanisms, and further identifying novel T and B cell subgroups with functional characterization, will facilitate the development of more effective strategies to treat SS.