Search Results (561)

Stage IV colorectal cancer has a poor prognosis, and liver metastases are prone to recurrence, even after resection. This study aimed to identify common cancer antigens, using immunohistochemical staining, as promising targets for antigen-specific immunotherapies in colorectal cancer. We analyzed expression levels and intracellular localization of seven common cancer antigens, CLDN1, EphB4, LAT1, FOXM1, HSP105α, ROBO1, and SPARC, and human leukocyte antigen (HLA) class I via immunohistochemical staining of 85 surgical specimens from primaries and liver metastases. Staining intensity and positive staining were scored to evaluate antigen expression. In 25 primaries, seven cancer antigens were expressed in 88–96% of cases, while HLA class I was expressed on the cell membrane in 80.0% of cases. In 60 liver metastases, FOXM1 and SPARC expression were approximately half that observed in the primaries. Other antigens and HLA class I were highly expressed in both. Most of the primaries and liver metastases may benefit from chimeric antigen receptor-T cell therapy targeting CLDN1, EphB4, and LAT1. Cases with high HLA class I expression may be suitable for vaccine-based and T cell receptor-T cell therapy targeting CLDN1, EphB4, LAT1, FOXM1, HSP105α, ROBO1, and SPARC for primaries and targeting antigens, excluding FOXM1 and SPARC, for liver metastases. Full article

Cryotherapy could stimulate immune responses and induce abscopal effects. A novel technique was developed for treating spinal bone tumors involving the use of frozen tumor-containing autologous bone grafts for anterior spinal reconstruction following total en-bloc spondylectomy, with the aim of activating cryoimmunity. This study focused on analyzing changes in the T-cell receptor (TCR) repertoire after surgery to evaluate T-cell diversity. Blood samples were collected pre- and post-operatively, with subsequent RNA extraction and immunosequencing. Compared to pre-surgery samples, the diversity and abundance of the Complementarity-Determining Region 3, regions of the TCR α and β chains decreased, suggesting that more selective clones may have emerged and influenced immune responses. Through TCR repertoire analysis, this study demonstrated that transplantation of frozen tumor-containing autologous bone impacted the immune system. This study is expected to provide a foundation for developing treatments that may enhance immune activation. Full article

Despite targeting mainly the respiratory tract, SARS-CoV-2 disrupts T cell homeostasis in ways that may explain both acute lethality and long-term immunological consequences. In this study, we aimed to evaluate the T-cell-mediated chain of immunity and formation of TCR via TREC assessment in COVID-19 and long COVID (LC). For this study, we collected 231 blood samples taken from patients with acute COVID-19 (n = 71), convalescents (n = 51), people diagnosed with LC (n = 63), and healthy volunteers (n = 46). With flow cytometry, we assessed levels of CD4+ and CD8+ minor T cell subpopulations (i.e., naïve, central and effector memory cells (CM and EM), Th1, Th2, Th17, Tfh, Tc1, Tc2, Tc17, Tc17.1, and subpopulations of effector cells (pE1, pE2, effector cells)). Additionally, we measured TREC levels. We found distinct changes in immune cell distribution—whilst distribution of major subpopulations of T cells was similar between cohorts, we noted that COVID-19 was associated with a decrease in naïve Th and CTLs, an increase in Th2/Tc2 lymphocyte polarization, an increase in CM cells, and a decrease in effector memory cells 1,3, and TEMRA cells. LC was associated with naïve CTL increase, polarization towards Th2 population, and a decrease in Tc1, Tc2, Em2, 3, 4 cells. We also noted TREC correlating with naïve cells subpopulations. Our findings suggest ongoing immune dysregulation, possibly driven by persistent antigen exposure or tissue migration of effector cells. The positive correlation between TREC levels and naïve T cells in LC patients points to residual thymic activity. The observed Th2/Th17 bias supports the hypothesis that LC involves autoimmune mechanisms, potentially driven by molecular mimicry or loss of immune tolerance. Full article

The immune landscape of tumor-draining lymph nodes (TDLNs) plays a critical role in shaping antitumor responses and influencing prognosis in oral squamous cell carcinoma (OSCC). Among patients with lymph node (LN) metastasis, clinical outcomes vary widely, yet reliable biomarkers for prognostic stratification remain limited. This study aimed to identify immune features in tumors and LNs that differentiate between favorable and poor outcomes in OSCC patients with nodal metastasis. We analyzed T cell receptor (TCR) CDR3 repertoires and the expression of immune-related genes in primary tumors and paired sentinel LNs from OSCC patients who underwent tumor resection and lymphadenectomy. Patients were divided into three groups: Group A (no nodal metastasis), Group B1 (metastasis without recurrence), and Group B2 (metastasis with recurrence). TCR diversity was assessed using the Shannon index. The expression of immune-related genes (e.g., CD3E, CD4, CD8B, FOXP3, CTLA4, IL2, IL4) was measured by quantitative PCR and normalized to GAPDH. TCR diversity was lower in tumors than in non-metastatic LNs, reflecting clonal expansion. Metastatic LNs exhibited tumor-like diversity, suggesting infiltration by tumor-reactive clones. Tumor gene expression did not differ across groups, but LNs from metastatic cases showed the reduced expression of several immune genes. Notably, CD3E, CD8B, CTLA4, IL2, and IL4 distinguished B1 from B2. The immune profiling of LNs offers superior prognostic value over tumor analysis in OSCC patients with LN metastasis. LN-based evaluation may aid in postoperative risk stratification and personalized postoperative management and could inform decisions regarding adjuvant therapy and follow-up strategies. Full article

CD8+ T lymphocytes (CTLs) act as serial killers of infected or malignant cells by releasing large amounts of interferon-gamma (IFNγ) and granzymes. Although IFNγ is a pleiotropic cytokine with diverse immunomodulatory functions, its precise spatiotemporal regulation and role in CTL-mediated cytotoxicity remain incompletely understood. Using wild-type and granzyme B-mTFP knock-in mice, we employed a combination of in vitro approaches, including T cell isolation and culture, plate-bound anti-CD3e stimulation, degranulation assays, flow cytometry, immunofluorescence, and structured illumination microscopy, to investigate IFNγ dynamics in CTLs. IFNγ expression in CTLs was rapid, transient, and strictly dependent on T cell receptor (TCR) activation. We identified two functionally distinct IFNγ-producing subsets: IFNγ^high (IFNγ^hi) and IFNγ^low (IFNγ^lo) CTLs. IFNγ^hi CTLs exhibited an effector/effector memory phenotype, significantly elevated CD107a surface expression (a marker of lytic granule exocytosis), and higher colocalization with cis-Golgi and granzyme B compared to IFNγ^lo CTLs. Furthermore, CRTAM, an early activation marker, correlated with IFNγ expression in naive CTLs. Our findings establish a link between elevated IFNγ production and enhanced CTL cytotoxicity, implicating CRTAM as a potential regulator of early CTL activation and IFNγ induction. These insights provide a foundation for optimizing T cell-based immunotherapies against infections and cancers. Full article

Uveal melanoma (UM), the most common primary intraocular malignancy in adults, poses a unique clinical challenge due to its high propensity for liver metastasis and poor responsiveness to conventional therapies. Despite the expanding landscape of immunotherapy in oncology, progress in managing metastatic uveal melanoma (mUM) remains limited, and no universally accepted standard of care has been established. In this review, we examine the current state and evolving strategies in immunotherapy for mUM, focusing on immune checkpoint inhibitors (ICIs), T cell receptor (TCR)-engineered therapies, and tumor-targeted vaccines. We also present a meta-analytical comparison of clinical outcomes between ICI monotherapy and combination regimens, alongside the recently FDA-approved T cell engager tebentafusp. Our analysis indicates that the triple combination of Ipilimumab, anti-PD-1 agents, and tebentafusp significantly enhances objective response rates, disease control rates, 1-year overall survival rates, and median overall survival (mOS) compared to ICI monotherapy alone. However, this enhanced efficacy is accompanied by increased toxicity due to broader immune activation. In contrast, tebentafusp offers superior tumor specificity and a more favorable safety profile in HLA-A*02:01-positive patients, positioning it as a preferred therapeutic option for this genetically defined subset of UM. Additionally, early-phase studies involving dendritic cell-based immunotherapies and peptide vaccines has shown encouraging signs of tumor-specific immune activation, along with improved tolerability. Collectively, this review underscores the urgent need for more precise and effective immunotherapeutic approaches tailored to the unique biology of mUM. Full article

SLE is characterized by the generation of a variety of autoantibodies including anti-dsDNA autoantibodies, causing damage in various organs. If autoimmunity is defined by the generation of a variety of autoantibodies against the self, SLE is the only disease to qualify. Identification of the SLE-causing factor must fulfill the following criteria: (i) the factor induces SLE, (ii) the factor is operating in active SLE and (iii) SLE heals after removal of the factor. All candidate factors are reviewed from this viewpoint in this review. As to the cause of SLE, high levels of interferon α can induce SLE; however, interferon α in most patients did not reach this high level. BAFF (B cell activating factor of the TNF family) is increased in SLE. BAFF itself induced some manifestation of SLE, whereas removal of interferon α or BAFF by an antibody (Ab) did not heal SLE. BXSB male mice with a duplicated TLR7 gene develop SLE; however, the gene Sle1 is also required for the development of SLE. In addition, sanroque mice develop a variety of autoantibodies and SLE; the sanroque mutation, which disrupts one of the repressors of ICOS, results in increased CCR7^lo CXCR5⁺Tfh cells, IL-21 and SLE. ICOS⁺T follicular helper (Tfh) cells increase in SLE and SLE-model (NZBxNZW)F1 mice, and the blockade of Tfh development ameliorated SLE, indicating the importance of Tfh cells in the pathogenesis of SLE. Self-organized criticality theory shows that SLE is caused by repeated infection, wherein SLE-inducing pathogens can vary individually depending on one’s HLA; however, the pathogen presented on HLA stimulates the T cell receptor (TCR) strongly beyond self-organized criticality. This stimulation generates TCR-revised, autoreactive DOCK8⁺Tfh cells, which induced a variety of autoantibodies and SLE. The SARS-CoV-2 virus is an example pathogen because SLE occurs after SARS-CoV-2 infection and vaccination. DOCK8⁺Tfh cells and SLE decreased after conventional or anti-DOCK Ab therapies. Thus, DOCK8⁺Tfh cells newly generated after repeated infection fulfill the criteria (i), (ii) and (iii) as the cause of SLE. Full article

It is well recognized that patients with type 2 diabetes mellitus (T2DM) exhibit significant impairment of immune function resulting in a higher frequency of infections. We hypothesize in this study that a likely contributor to immune dysfunction in T2DM is alteration of T lymphocyte signaling functions induced by chronic hyperglycemia. In this study we have utilized the established UC Davis Type 2 Diabetes Mellitus (UCD-T2DM) rat model of human T2DM to investigate whether progressive hyperglycemia diminishes T cell receptor (TCR)-releasable endoplasmic reticulum (ER) Ca²⁺ stores, an essential early antigen-stimulated signal driving T cell activation. Furthermore, results from this study demonstrate that chronic hyperglycemia markedly alters the expression profile of the sarco/endoplasmic reticulum Ca²⁺-ATPase (SERCA) Ca²⁺ ion pumps, which are the major enzymatic ion transporters maintaining replenished TCR-sensitive Ca²⁺ pools. We conducted companion experiments using Jurkat T lymphocytes exposed to high glucose which allowed finer resolution of early disruptions to ER Ca²⁺ store integrity and greater clarity on SERCA isoform-specific roles in diabetes-induced Ca²⁺ signal dysregulation. In summary, these experiments suggest that hyperglycemia in T2DM drives an ER stress state manifesting in reduced expression of the SERCA pumps, erosion of ER Ca²⁺ stores and culminating in T cell and immune dysfunction. Full article

Background/Objectives: The physiological activation of cytotoxic CD8^pos T cells (CTLs) relies on the engagement of the TCR/CD3 complex with cognate peptide-HLA class I (pHLA-I) on target cells, triggering cell lysis with appropriate cytokine release and minimized off-target toxicity. In contrast, current immunotherapies for CD19-expressing hematological malignancies, such as chimeric antigen receptor (CAR) T cells and bispecific T cell engagers (BiTEs), bypass TCR/pHLA interactions, resulting in CTL hyperactivation and excessive cytokine release, which frequently cause severe immune-related adverse events (irAEs). Thus, there is a pressing need for T cell-based therapies that preserve physiological activation while maintaining antitumor efficacy. Methods: To address this, we developed CD19-ReTARG^TPR, a novel fusion protein consisting of the immunodominant cytomegalovirus (CMV) pp65-derived peptide TPRVTGGAM (TPR) covalently presented by a soluble HLA-B*07:02/β2-microglobulin complex fused to a high-affinity CD19-targeting Fab antibody fragment. The treatment of CD19-expressing cancer cells with CD19-ReTARG^TPR makes them recognizable for pre-existing anti-CMV_pp65 CTLs via physiological TCR-pHLA engagement. Results: Our preclinical data demonstrate that CD19-ReTARG^TPR efficiently redirects anti-CMV CTLs to eliminate CD19-expressing cancer cells, including both established cell lines and primary chronic lymphocytic leukemia (CLL) cells. Unlike CD19-directed CAR T cells or the CD19/CD3 BiTE blinatumomab, CD19-ReTARG^TPR mediated robust cytotoxic activity without triggering supraphysiological cytokine release. Importantly, this approach retained efficacy even against cancer cells with low CD19 expression. Conclusions: In summary, we provide a robust proof-of-concept study and show that CD19-ReTARG^TPR offers a promising alternative strategy for T cell redirection, enabling the selective and effective killing of CD19-expressing malignancies while minimizing cytokine-driven toxicities through physiological CTL activation pathways. Full article

T-cell receptors (TCRs) exhibit degeneracy, enabling individual TCRs to recognize multiple altered peptide ligands (APLs) derived from a single cognate antigen. This characteristic has been involved in the pathogenesis of autoimmune diseases through cross-reactivity between microbial and self-antigens. Cytotoxic T lymphocytes (CTLs), which recognize peptide–MHC class I complexes via TCRs, play a critical role in the immune response against viral infections. However, the extent to which TCR degeneracy within a population of virus-specific CTLs contributes to effective viral control remains poorly understood. In this study, we investigated the magnitude and functional relevance of TCR degeneracy in CTLs targeting an immunodominant epitope of human T-cell leukemia virus type 1 (HTLV-1) in patients with HTLV-1-associated myelopathy (HAM). Using peripheral blood mononuclear cells (PBMCs) from these patients, we quantified TCR degeneracy at the population level by comparing CTL responses to a panel of APLs with responses to the cognate epitope. Our findings demonstrated that increased TCR degeneracy, particularly at the primary TCR contact residue at position 5 of the antigen, was inversely correlated with HTLV-1 proviral load (p = 0.038, R = −0.40), despite similar functional avidity across patient-derived CTLs. Viral sequencing further revealed that CTLs with high TCR degeneracy exerted stronger selective pressure on the virus, as indicated by a higher frequency of nonsynonymous substitutions within the epitope-encoding region in patients with highly degenerate TCR repertoires. Moreover, TCR degeneracy was positively correlated with the recognition rate of epitope variants (p = 0.018, R = 0.76), suggesting that CTLs with high TCR degeneracy exhibited enhanced recognition of naturally occurring epitope variants compared to those with low TCR degeneracy. Taken together, these results suggest that virus-specific CTLs with high TCR degeneracy possess superior antiviral capacity, characterized by broadened epitope recognition and more effective suppression of HTLV-1 infection. To our knowledge, this is the first study to systematically quantify TCR degeneracy in HTLV-1-specific CTLs and evaluate its contribution to viral control in HAM patients. These findings establish TCR degeneracy as a critical determinant of antiviral efficacy and provide a novel immunological insight into the mechanisms of viral suppression in chronic HTLV-1 infection. Full article

Peptide vaccines possess several advantages over mRNA vaccines but are generally less effective at inducing antitumor immunity. The bottlenecks limiting peptide vaccine efficacy could be elucidated by tracking and comparing vaccine-induced T-lymphocytes in successful and unsuccessful cases. Here we have applied our recent database of neoantigen-specific T cell receptors (TCRs) to profile tumor-specific T cells following vaccination with a neoantigen peptide vaccine and to correlate this with the response. Mice were vaccinated prophylactically with p30 peptide encoding B16 melanoma neoantigen (K739N mutation in Kif18b gene). The B16F0 melanoma in the vaccinated mice was additionally treated by a CTLA-4 checkpoint blockade. T cells from the tumors, tumor-draining lymph nodes (tdLNs) and vaccine depots were isolated, phenotyped, sorted by subsets and sequenced for TCR repertoires. The vaccine induced the accumulation of tumor-specific CD4+ Th cells in the tdLNs, while in the tumors these cells were present and their frequencies were not changed by the vaccine. These cells also accumulated at the vaccine depots, where they were phenotypically skewed by the vaccine components; however, these effects were minor due to approximately 50-fold lower cell quantities compared to the tdLNs. Only some of the p30-specific Th cells showed tumoricidal activity, as revealed by the reverse correlation of their frequencies in the tdLNs with the tumor size. The CTLA-4 blockade did not affect the tumor growth or the frequencies of tumor-specific cells but did stimulate Th cell motility. Thus, we have shown that tumor-specific Th clones accumulate and/or expand in the tdLNs, which correlates with tumor suppression but only for some of these clones. Tumor infiltration by these clones is not correlated with the growth rate. Full article

FOXP3+ regulatory T cells (Tregs) play a central role in the regulation of the immune system. Human Tregs preferentially express a FOXP3 isoform known as delta 2, which lacks exon 2. In addition to FOXP3, Tregs also express isoforms of other Treg-related molecules, such as CTLA-4 and IKZF-2. It is hypothesized that Tregs possess a unique isoform repertoire based on their unique gene and isoform expression profiles, which include FOXP3. Here, we identified a Treg-specific unique isoform repertoire confirmed by long-read high-throughput isoform sequencing called Iso-seq, which is uniquely capable of providing data on genome-wide isoform usage. Notably, while conventional T cells (Tconvs) do not exhibit this pattern, Tregs preferentially express the full-length FOXP3 isoform. Interestingly, the preferential expression of ICOS and PD-L1 upon T-cell receptor (TCR) stimulation was noted in activated Tregs but not in Tconvs or non-activated Tregs. Moreover, using a PD-L1 antibody blockade on Tregs did not diminish FOXP3 expression; however, it significantly reduced the suppressive function. Therefore, Tregs may have a unique isoform repertoire, which becomes pronounced upon polyclonal TCR stimulation. Full article

Ruxolitinib, a clinically approved JAK1/2 inhibitor used in the treatment of hematologic malignancies and inflammatory conditions, has been shown to interfere with the function of cytotoxic T lymphocytes (CTLs). Previous studies supported the involvement of the multidrug resistance transporter P-glycoprotein (Pgp/ABCB1) in CTL biology; however, the nature of its regulation remains unclear. To address this, we investigated the impact of ruxolitinib on Pgp expression and function in human CD8⁺ T cells. We demonstrate that CD8⁺ T lymphocytes express Pgp dynamically at both the mRNA and protein levels across naïve, short-term, and long-term activation states. Ruxolitinib increased the calcein accumulation in human Pgp-overexpressing NIH-3T3 cells and in CTLs and directly modulated Pgp function by increasing its basal ATPase activity in a concentration-dependent manner (10–100 μM), similar to the effect of the known Pgp substrate/modulator verapamil. Although measurable ATPase stimulation and transport inhibition were observed at supratherapeutic concentrations of ruxolitinib, its Pgp-mediated efflux may also occur at therapeutically relevant concentrations. In contrast, at therapeutically relevant plasma concentrations (1–3 μM), ruxolitinib significantly stabilized the mRNA expression of Pgp during early T-cell receptor (TCR) activation and inhibited the TCR-induced upregulation of Pgp, CD8, and PD-1 surface markers, suggesting its interference with activation-associated differentiation. At these same concentrations, ruxolitinib also impaired CCL19-directed transmigration of CTLs across human umbilical vein endothelial cell (HUVEC) monolayers, indicating disruption of lymphoid homing cues. Collectively, these findings demonstrate that ruxolitinib modulates Pgp at both the transcriptional and functional levels, with distinct concentration dependence. The ability of ruxolitinib to alter CTL activation and migration at clinically relevant plasma concentrations highlights the need for careful evaluation of JAK inhibitor–mediated immunomodulation and its implications for vaccination, transplantation, and T cell-based immunotherapies. Full article

Chimeric antigen receptor (CAR)-T and T-cell receptor (TCR)-engineered T-cell (TCR-T) therapies have revolutionized the treatment of hematological malignancies; however, their application to solid tumors remains a formidable challenge. The immunosuppressive tumor microenvironment, antigen heterogeneity, and manufacturing complexity limit the clinical efficacy and scalability of these treatment modalities. This review provides a comprehensive analysis of the current clinical development strategies for CAR-T and TCR-T cell therapies for solid tumors. Herein, we discuss recent breakthroughs and highlight the potential of TCR-T cell therapy. Furthermore, innovative approaches for enhancing CAR-T cell function in solid tumors (e.g., in vivo engineering; induced pluripotent stem cell-derived allogeneic CAR-T cells; armored CAR constructs; dual-antigen targeting; and combination regimens with checkpoint inhibitors, chemotherapy, radiotherapy, and oncolytic viruses) are explored. We also present trends in global patent activity, revealing a marked acceleration in CAR-T- and TCR-T-related innovations, with the United States and China leading with respect to application volumes. This field is increasingly characterized by multidisciplinary collaborations between academia and industry, driving the development of next-generation platforms, including messenger RNA-based and off-the-shelf cell therapies. Although no CAR-T product has been approved for solid tumors, these findings underscore the accelerating momentum and translational promise of adoptive cell therapies. Addressing the unique biological and logistical challenges of solid tumors is essential for realizing the full potential of these transformative immunotherapies. Full article

Currently, there are two major theories regarding the pathogenesis of sepsis: hyperimmune and hypoimmune. The hyperimmune theory suggests that a cytokine storm causes the symptoms of sepsis. On the contrary, the hypoimmune theory suggests that immunosuppression causes the manifestations of sepsis. By conducting a microarray analysis on peripheral leukocytes from patients with sepsis, this study found that hyperactivity of TH17 immunity was noted in sepsis patients. Innate immunity-related genes are significantly upregulated, including CD14, TLR1,2,4,5,8, HSP70, CEBP proteins, AP1 (JUNB and FOSL2), TGFB1, IL6, TGFA, CSF2 receptor, TNFRSF1A, S100A binding proteins, CCR2, FPR2, amyloid proteins, pentraxin, defensins, CLEC5A, whole complement machinery, CPD, NCF, MMP, neutrophil elastase, caspases, IgG and IgA Fc receptors (CD64, CD32), ALOX5, PTGS, LTB4R, LTA4H, and ICAM1. The majority of adaptive immunity genes were downregulated, including MHC-related genes, TCR genes, granzymes/perforin, CD40, CD8, CD3, TCR signaling, BCR signaling, T and B cell-specific transcription factors, NK killer receptors, and TH17 helper-specific transcription factors (STAT3, RORA, and REL), as well as Treg-related genes, including TGFB1, IL15, STAT5B, SMAD2/4, CD36, and thrombospondin. The findings of this study show that Th17 with Treg over-presentation play an important role in the pathophysiology of sepsis. Full article