Higher TIGIT Research Articles

Relationship between TIGIT expression on T cells and the prognosis of patients with hepatocellular carcinoma

BackgroundTranscatheter arterial chemoembolization (TACE) combined with targeted therapy and immunotherapy can significantly improve the prognosis of patients with hepatocellular carcinoma (HCC). T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domains (TIGIT) is a novel immunosuppressive molecule. This study aimed to analyze the clinical correlation between TIGIT expression on T cells and patients with HCC.MethodsClinical data from 140 patients with HCC were retrospectively collected, and TIGIT expression on T cells was examined in each patient. Patients were subsequently divided into high- and low-expression groups, and their prognosis was analyzed.ResultsPatients with a high TIGIT expression on their T cells at baseline had a larger tumor volume, later staging, higher proportion of regulatory T cells, higher blood concentrations of interleukin (IL)-6 and IL-10, and lower interferon-γ concentrations. Following TACE, CD155 concentration decreased; however, TACE did not affect TIGIT expression on T cells. Additionally, among patients receiving TACE combined with apatinib and camrelizumab treatment, patients with a high TIGIT expression on T cells had significantly shorter progression-free survival (PFS) and overall survival times than those of patients in the low-expression group. Patients receiving TACE combined with apatinib and camrelizumab treatment with higher TIGIT expression have shorter PFS time than those receiving TACE combined with apatinib treatment.ConclusionsPatients with HCC that have a high TIGIT expression on their T cells exhibited poorer baseline characteristics, immunosuppressive status, and prognosis after receiving TACE combined with apatinib and camrelizumab and maybe more suited to receive TACE combined with apatinib treatment instead.

Expression and Prognostic Significance of LAG-3, TIGIT, VISTA, and IDO1 in Endometrial Serous Carcinoma

Endometrial serous carcinoma (ESC) is an uncommon, aggressive type of endometrial cancer. While immune checkpoint blockade has emerged as a promising treatment option for endometrial carcinomas, research on the expression of immune checkpoints that could serve as prospective immunotherapy targets in ESC is limited. We examined the prevalence and prognostic value of LAG-3, TIGIT, VISTA, and IDO1 in 94 cases of ESC and correlated their expression with CD8+ and FOXP3+ tumor infiltrating lymphocytes (TIL). We observed a positive correlation between LAG-3, TIGIT and VISTA expressed on immune cells, and between these markers and CD8+ and FOXP3+ TIL density. In Kaplan-Meier survival analysis, tumors with high levels of LAG-3 and TIGIT expression had better progression free survival (PFS) and overall survival (OS) than those with lower levels of expression (LAG-3: PFS, p=0.03, OS, p=0.04; TIGIT: PFS, p=0.01, OS, p=0.009). In multivariate analysis, only high TIGIT expression was of independent prognostic value for better overall survival. VISTA expression in immune or tumor cells, and IDO1 expression in tumor cells, did not show a significant association with survival. Our data indicate that LAG-3, TIGIT, and VISTA immune checkpoints have roles in the microenvironment of ESC, and their expression patterns highlight the complex interactions among the different components of this system. High levels of these markers, together with high CD8+ TIL, suggests the potential immunogenicity of a subset of these tumors. Further studies are needed to elucidate the roles of various immune components in the ESC microenvironment and their association with intrinsic tumor properties.

T cell expressions of aberrant gene signatures and Co-inhibitory receptors (Co-IRs) as predictors of renal damage and lupus disease activity

BackgroundSystemic lupus erythematosus (SLE) is distinguished by an extensive range of clinical heterogeneity with unpredictable disease flares and organ damage. This research investigates the potential of aberrant signatures on T cell genes, soluble Co-IRs/ligands, and Co-IRs expression on T cells as biomarkers for lupus disease parameters.MethodsComparative transcriptome profiling analysis of non-renal and end-stage renal disease (ESRD) phenotypes of SLE was performed using CD4 + and CD8 + cDNA microarrays of sorted T cells. Comparing the expression of Co-IRs on T cells and serum soluble mediators among healthy and SLE phenotypes.ResultsSLE patients with ESRD were downregulated CD38, PLEK, interferon-γ, CX3CR1, FGFBP2, and SLCO4C1 transcripts on CD4 + and CD8 + T cells simultaneously and NKG7, FCRL6, GZMB/H, FcγRIII, ITGAM, Fas ligand, TBX21, LYN, granulysin, CCL4L1, CMKLR1, HLA-DRβ, KIR2DL3, and KLRD1 in CD8 T cells. Pathway enrichment and PPI network analyses revealed that the overwhelming majority of Differentially Expressed Genes (DEGs) have been affiliated with novel cytotoxic, antigen presentation, and chemokine-cell migration signature pathways. CD8 + GZMK + T cells that are varied in nature, including CD161 + Mucosal-associated invariant T (MAIT) cells and CD161- aged-associated T (Taa) cells and CD161-GZMK + GZMB + T cells might account for a higher level of GZMK in CD8 + T cells associated with ESRD. SLE patients have higher TIGIT + , PD1 + , and lower CD127 + cell percentages on CD4 + T cells, higher TIM3 + , TIGIT + , HLA-DR + cell frequency, and lower MFI expression of CD127, CD160 in CD8 T cells. Co-IRs expression in T cells was correlated with soluble PD-1, PDL-2, and TIM3 levels, as well as SLE disease activity, clinical phenotypes, and immune-therapy responses.ConclusionThe signature of dysfunctional pathways defines a distinct immunity pattern in LN ESRD patients. Expression levels of Co-IRs in peripheral blood T cells and serum levels of soluble PD1/PDL-2/TIM3 can serve as biomarkers for evaluating clinical parameters and therapeutic responses.

MGMT unmethylation and high levels of CD47 and TIGIT indicate a poor prognosis in adult diffuse gliomas.

In 2021, the World Health Organization published a new classification system for central nervous system tumors. This study reclassified the adult diffuse glioma (ADG) into astrocytoma, oligodendroglioma, and glioblastoma (GBM) according to the new tumor classification. The association of TERT promoter (pTERT) mutation, MGMT methylation, and CD47/TIGIT expression with patient prognosis was investigated. Immunohistochemical analysis showed that the expression levels of CD47 and TIGIT in tumor tissues were significantly higher than those in normal brain tissues. CD47 levels were higher in GBM and grade 4 astrocytoma tissues. TIGIT expression was also higher in patients with GBM. The high expressions of CD47, TIGIT, and CD47/TIGIT were positively correlated with MGMT unmethylation but not pTERT mutation. Moreover, MGMT unmethylation was associated with poor overall survival in astrocytoma. High CD47, TIGIT, and CD47/TIGIT levels were associated with significantly reduced survival in ADG and GBM. GBM, MGMT unmethylation, and high CD47 expression were independent prognostic factors for overall survival in ADG. Collectively, these results showed that the MGMT unmethylation and high levels of CD47 and TIGIT are associated with a poor prognosis in ADG. Patients with high CD47 and TIGIT expression may benefit from anti-CD47 and TIGIT immunotherapy.

Abstract C012: TIGIT expression correlates to worse overall survival in primary and metastatic pancreatic ductal adenocarcinoma

Abstract Pancreatic Cancer has a 12% 5-year survival rate due to late-stage detection and lack of many chemotherapy or targeted therapy options. TIGIT is an immune checkpoint inhibitor being explored in clinical trials in pancreatic cancer due to the implications of its ligand (CD155) promoting immune evasion. TIGIT is a marker of T cell exhaustion and plays a key role in the inhibition of anti-tumor immune responses. We hypothesize that targeted anti-TIGIT therapy, in conjunction with other therapies targeting the tumor microenvironment, could reverse immune suppression that is characteristic of pancreatic ductal adenocarcinoma (PDAC). As such, here we aim to quantify TIGIT expression using automated RNAscope technology and to correlate it with overall patient survival. We performed RNAscope in situ hybridization and immunohistochemistry on 25 primary and 4 metastatic (liver) formalin-fixed paraffin-embedded (FFPE) tissue sections from patients with histologically confirmed PDAC. A nuclear counterstain combined with an RNAscope probe specific for the human TIGIT mRNA was utilized. Slides were scanned at 40X magnification with an automated slide scanner and quantified using the ISH-IHC module of the HALO-v3.5 software. After cells were segmented based on nuclear recognition, the presence of TIGIT probe within the cytoplasm of each cell was determined and quantified. Percent positive cell values were then exported for statistical analysis in SPSS. De-identified clinical metadata was obtained from REDCap, a cloud-based HIPAA-compliant database used to compile patient data for research purposes. Gender, survival months, ethnicity, race, tumor histology, stage, cancer history, treatment status, and comorbidities were evaluated. We analyzed a cohort of 29 histologically-confirmed surgically resected PDACs, comprised of 25 primary pancreatic tumor samples and 4 metastatic liver core biopsies. The mean percentage of TIGIT positive cells was 63%. From this, the TIGIT high versus low threshold was determined to be 70%. High TIGIT was associated with significantly lower overall survival (p=.013), suggesting that expression of TIGIT and T cell exhaustion may predict overall worse survival. The median overall survival months for the TIGIT low group was 321 months versus 106 months for the TIGIT high group. This data leads us to hypothesize that expression of TIGIT and T cell exhaustion may predict worse overall survival. Anti-TIGIT medications are currently in clinical trials for metastatic PDAC. Here we demonstrate that high TIGIT expression is associated with an overall worse prognosis and present a novel, automated TIGIT detection protocol that may be used to determine if patients are candidates for anti-TIGIT therapy. In a clinical setting, this novel, automated biomarker TIGIT detection protocol could be used to select candidates for anti-TIGIT therapy. This may lead to improved overall patient survival. Citation Format: Madison George, Julie Clark, Kendyll Gartrelle, Georges Nassif, Donald Rempinski, Daniel Long, Hui-Ju Wen, Simone Benitz, Samuel Zwernik, Rupen Shah, Hakmin Park, David Kwon, Philip Philip, Gazala Khan, Howard Crawford, Brian Theisen, Nina Steele. TIGIT expression correlates to worse overall survival in primary and metastatic pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr C012.

TIGIT is Frequently Expressed in the Tumor Microenvironment of Select Lymphomas: Implications for Targeted Therapy.

Immune checkpoint inhibitors against Programmed Cell Death Protein 1/Programmed Cell (PD-1/PD-L1) and CTLA-4/B7 axes have had limited success in hematologic malignancies, requiring the need to explore alternative targets such as T-cell immunoreceptor with Ig and ITIM domains (TIGIT)/CD155 to improve durable clinical responses. We undertook this study to investigate the expression profile of TIGIT such that the potential efficacy of TIGIT blockade could be mapped among lymphoma subtypes. We validated an immunohistochemical assay for TIGIT and evaluated its expression in lymphoma and tumor microenvironment (TME) cells in 661 lymphoma/leukemia biopsies. Multiplex immunofluorescence was used for correlation with normal TME cell subsets. Tumor or TME TIGIT-positivity was defined as moderate to strong membrane staining in at least 10% of tumor or TME cells, respectively. TME TIGIT expression was correlated with overall survival and progression-free survival and comparison with PD-L1 expression. In most cases, lymphoma cells were TIGIT-negative except for angioimmunoblastic and peripheral T-cell lymphomas, which showed 91% and 47% positivity, respectively. A high proportion of small B-cell lymphoma and anaplastic large cell lymphoma cases had TIGIT-positive TME cells. Chronic lymphocytic leukemia/small lymphocytic lymphoma patients with TIGIT-negative TME cells showed significantly shorter overall survival ( P =0.04). No other statistically significant differences were found. When TIGIT was expressed in TME cells, there were a comparable number of TIGIT-positive only and dual TIGIT/PD-L1 positive cases except for more TIGIT-positive only cases in CLL/SLL. TIGIT expression shows distinctive profiles among lymphoma subtypes. Chronic lymphocytic leukemia/small lymphocytic lymphoma and anaplastic large cell lymphoma demonstrated high TME TIGIT expression compared with PD-L1, with a high proportion of dual TIGIT and PD-L1-positivity. Our results are likely to contribute to the design and correlative study of therapeutic response in clinical trials targeting TIGIT alone or in combination with PD1/PDL1.

Immunoswitch Nanomodulators Enable Active Targeting and Selective Proliferation of Regulatory T Cells for Multiple Sclerosis Therapy.

Interleukin-2 (IL-2) used in multiple sclerosis (MS) therapy modulates the balance between regulatory T (Treg) cells and effector T (Teff) cells. However, the off-target activation of Teff cells by IL-2 limits its clinical application. Therefore, a rapidly prepared immunoswitch nanomodulator termed aT-IL2C NPs was developed, which specifically recognized Treg cells with high TIGIT expression thanks to the presence of an anti-TIGIT and an IL-2/JES6-1 complex (IL2C) being delivered to Treg cells but not to Teff cells with low TIGIT expression. Then, IL2C released IL-2 due to the specific expression of the high-affinity IL-2 receptor on Treg cells, thus enabling the active targeting and selective proliferation of Treg cells. Moreover, the anti-TIGIT of aT-IL2C NPs selectively inhibited the proliferation of Teff cells while leaving the proliferation of Treg cells unaffected. In addition, since the IL-2 receptor on Teff cells had medium-affinity, the IL2C hardly released IL-2 to Teff cells, thus enabling the inhibition of Teff cell proliferation. The treatment of experimental autoimmune encephalomyelitis (EAE) mice with aT-IL2C NPs ameliorated the severity of the EAE and restored white matter integrity. Collectively, this work described a potential promising agent for effective MS therapy.

Evaluating Tumor-Intrinsic and Patient-Specific Mechanisms of Resistance to Teclistamab in Anti-BCMA Exposed and Naïve Multiple Myeloma

Background: Teclistamab (Tec) is a CD3 x BCMA bispecific antibody granted accelerated FDA approval for treating relapsed/refractory (RR) multiple myeloma (MM) based off the results of the MajesTEC-1 trial (Usmani S, et al. Lancet 2021, Moreau P, et al. N Engl J Med 2022). However, patients with prior exposure to anti-BCMA therapies were excluded from this trial and there is no published data evaluating Tec efficacy in this setting. Additionally, little is known about tumor-intrinsic and patient-specific immunologic predictors of response to Tec. Methods: We performed an IRB-approved analysis of clinical outcomes for 52 commercially treated Tec patients treated as of 07/28/2023 at our center. Results were correlated to pre-treatment BCMA expression measured by immunohistochemistry (IHC). We also profiled peripheral blood T-cells from pre-treatment peripheral blood mononuclear cell (PBMC) samples from a sub cohort of patients via high-dimensional spectral cytometry using a 37-color panel including lineage, exhaustion, and activation markers. Results: Our commercial cohort was older (median age 70 vs 64), more heavily pretreated (median prior lines of therapy 7 vs 5) and had higher incidence of both high-risk cytogenetic abnormalities (33% vs 26%) and extramedullary disease (35% vs 17%) than the MajesTEC-1 population. Additionally, 52% had prior exposure to anti-BCMA therapies, including belantamab mafodotin (31%), anti-BCMA CAR T-cell therapies (37%), and anti-BCMA bispecific antibody therapies (4%), with some having exposure to multiple prior anti-BCMA therapies (17%). Among response evaluable patients (90%), with a median follow-up time of 100 days, the overall response rate (ORR) to Tec was 64% (36% ≥VGPR). Progression free survival (PFS) in patients without prior BCMA therapy was higher than in the anti-BCMA exposed population (median PFS NR vs 102 days, p = 0.032, Figure Panel A). However, the anti-BCMA therapy exposed population was more heavily pretreated (8 vs 5 median prior lines of therapy) and had more patients with high-risk cytogenetic abnormalities (46% vs 19%) and extramedullary disease (42% vs 27%) than the anti-BCMA therapy naïve cohort. No major differences in BCMA expression were noted between responding and non-responding patients or between anti-BCMA exposed and anti-BCMA naïve patients. However, two patients had absent BCMA expression following prior treatment with other BCMA targeting agents and did not respond to Tec. Cytokine release syndrome (CRS) during step-up dosing was strongly associated with Tec efficacy (median PFS NR vs 27 days, p <0.0001), with a 100% ORR for patients with CRS. Immune profiling experiments (Figure Panel B) revealed that Tec responders had peripheral blood enriched for both CD8 + effector memory T-cells (TEM, >6-fold increase, p = 0.0499) and CD8 + effector memory T-cells re-expressing CD45RA (TEMRA, >5-fold increase, p = 0.012) when compared to Tec non-responders. Tec non-responders had peripheral blood enriched for TIGIT + regulatory T-cells (Tregs, 3-fold increase, p = 0.03) when compared to Tec responders. No differences in PD-1, CTLA-4, LAG-3 or TIM-3 expression were observed in Tec responders vs non-responders. Patients with recent relapse from non-BCMA targeting bispecific antibodies (including products targeting FcRH5 or GPRC5D) had peripheral blood enriched for γδ T-cells with high TIGIT expression. Conclusion: Tec is an effective therapy in RRMM with a slightly lower efficacy observed in patients with prior anti-BCMA therapy exposure. PFS reductions among these anti-BCMA exposed patients may be partly due to independent disease associated risk factors. A pre-Tec peripheral blood T-cell population enriched with highly cytotoxic effector T-cells was associated with response to therapy, while suppressive TIGIT +Tregs were associated with nonresponse, suggesting a potential therapeutic role for TIGIT blockade or CD25 + cell depletion to enhance the therapeutic efficacy of bispecific antibodies. Clinical and translational data from additional patients will be presented at the meeting.

Itacitinib for Prevention of Graft-Versus-Host Disease and Cytokine Release Syndrome with T-Cell Replete Peripheral Blood Haploidentical Transplantation

Introduction: Haploidentical peripheral blood allogeneic hematopoietic cell transplantation (PB haplo-HCT) can be complicated by graft-versus-host disease (GVHD) and cytokine release syndrome (CRS). Acute GVHD rates are higher with PB grafts compared with bone marrow, affecting 35-45% of patients and outcomes are poor in steroid refractory cases. Severe CRS occurs in 10-15% of patients receiving PB haplo-HCT and is associated with high non-relapse mortality and one-year overall survival between 25-30%. As interferon-γ and IL-6 are important mediators in both acute GVHD and CRS, we hypothesized that JAK1 inhibition with itacitinib could prevent these toxicities without impairing engraftment. Here we report outcomes from our study of itacitinib with haplo-HCT (NCT03755414). Methods: Patients with AML, MDS, ALL, or NHL in remission undergoing PB haplo-HCT were treated with itacitinib 200 mg/day on days -3 through +100 (first 20 patients) or 180 (second 22 patients), followed by a taper. Myeloablative and reduced intensity conditioning were allowed. GVHD prophylaxis was tacrolimus, mycophenolate mofetil, and post-transplant cyclophosphamide. Primary outcomes were incidence of primary graft failure and incidence of grade III-IV acute GVHD. Secondary outcomes included incidence and severity of CRS, relapse, GRFS, and overall survival. Results: Forty-two patients were enrolled and underwent transplantation on study between November 2019 and December 2022, median days of follow up was 453 days (range 142-1259). The patient population had a median age of 60 years (20 - 73 years) with the majority of patients having AML (AML 60%, ALL 21%), MDS 10%, MF 5%, NHL 4%). All patients with AML, MDS, or ALL were in a complete morphologic remission, although 45% had disease by either cytogenetics, next generation sequencing, or measurable residual disease assay (flow cytometry for AML/MDS, NGS for ALL). There were no cases of grade III-IV acute GVHD. The cumulative incidence of grade II acute GVHD on day 100 was 17.3% (95% CI, 7% - 31%), day 180 was 20.5% and day 365 was 20.5%. There were no cases of severe CRS with 90% of patients having grade 1 CRS and 10% having no CRS. No anti-IL6R or steroid therapy was used. There were no cases of primary graft failure. The cumulative incidence of relapse at 1 year was 10% (95% CI, 3% to 22%) and at 2 years was 14% (95% CI, 5% to 29%). In patients who survived without relapse to day 100, the 1-year cumulative incidence of moderate or severe chronic GVHD was 5% (95% CI 1% - 17%). The refined GRFS at day +180 was 85% (95% CI 69% - 93%) and at day +365 was 79% (95% CI 62% - 89%). Overall survival at 180 days 87% (95% CI 72% - 94%) and at 1 year was 80% (95% CI 63% - 90%). Analysis of peripheral blood mononuclear cells at day +28, +60, and +100, revealed that patients on itacitinib, compared with control haplo-HCT patients, had lower numbers of CD4 and CD8 central memory T cells, lower numbers of CD4 and CD8 naïve T cells, and higher numbers of classical monocytes, nonclassical monocytes, and both myeloid and plasmacytoid dendritic cells. In itacitinib treated patients, T-cell subsets expressed lower LAG3 and PD-1 and higher TIGIT, while monocytes expressed higher HLA-DR, CD80, and CD86. Conclusions: Itacitinib with PB haplo-HCT was safe with low rates of acute and chronic GVHD, without increased risk of relapse or transplant related mortality. Severe CRS was not seen in this trial, and no anti-IL6 or steroid therapy was used. The addition of Jak inhibition to standard PtCy based GVHD prophylaxis was associated with encouraging rates of GRFS and OS on this pilot and expansion study. Patients on itacitinib have unique immune reconstitution characteristics both in terms of PBMC counts and signaling markers within subsets.

TIGIT transcriptomic expression and high levels of multiple checkpoints across diverse cancers.

e14637 Background: The T cell immunoreceptor with immunoglobulin and ITIM domain (TIGIT) is an immune inhibitory receptor present on some T- and natural killer (NK) cells. It plays an important role in restricting innate and adaptive immunity. Given this, studies to combine other checkpoint inhibitors with anti-TIGIT therapies are currently in development. Methods: The RNA expression levels of 397 genes in various types of solid tumors from 514 patients seen at the UCSD Moores Cancer Center were analyzed at a CLIA-licensed laboratory, (OmniSeq (https://www.omniseq.com/)). Transcript abundance was normalized to internal housekeeping gene profiles and ranked (0-100 percentile) in a standardized manner to a reference population of 735 tumors spanning 35 histologies. Odds ratio for high TIGIT expression (≥75 percentile rank) was calculated and Bonferroni corrected for multiple genes and cancer histologies with > 10 samples. Results: Of 514 tumors, 99 (19%) tumors had high TIGIT expression (32 different histologies). Cancers with the greatest proportion of high TIGIT expression were small intestine (33%; 4/12) pancreatic (31%; 17/55), lung (25%; 5/20), stomach (20%; 5/25), breast (20%; 10/49), colorectal (18%; 25/140), head and neck (17%; 2/12), sarcoma (13%; 3/24), and uterine (13%; 3/23), though there were no statistically significant associations between these histologies and high TIGIT. There were significant associations between high TIGIT and high PD-L1 (P < 0.0021), PD-1 (P < 0.0021), PD-L2 (P < 0.0021), CTLA-4 (P < 0.0021), OX40 (P < 0.0021), LAG3 (P < 0.0021), FOXP3 (P < 0.0021) expressions (p values Bonferroni adjusted for multiple comparisons). However, there was no significant association between tumor mutation burden ≥10 mutations/mb and high TIGIT. Conclusions: High TIGIT expression was found in 19% of 514 tumors (pan-cancer) and significantly associated with high RNA expression of other immune checkpoints (PD-L1, PD-1, PD-L2, CTLA-4, OX40, LAG3, FOXP3), many of which can be targeted by FDA-approved drugs or drugs in clinical trials. Ongoing studies combining TIGIT inhibitors and specific immune checkpoint inhibitors may yield more clinical benefit after personalized tumor immune profiling.

Expression and Clinical Significance of TIGIT in Primary Breast Cancer.

The roles of T cell immunoreceptor with Ig and ITIM domains (TIGIT) in the diagnosis of primary breast cancer (PBC) are still unclear. This study was designed to investigate the expression of TIGIT in PBC patients, with an aim to analyze its diagnostic value in PBC. We first explore the expression of TIGIT in cancer patients based on TCGA database, and then we analyzed its correlation with clinicopathological features. Afterwards, we compared the protein and mRNA expressions of TIGIT in two BC cell lines (MCF-7 and MDA-MB-231) and normal breast epithelial cell line (MCF-10A). Subsequently, 56 PBC female patients admitted to the Taizhou People's Hospital from October 2018 to June 2021 were included in this study. Flow cytometry was used to detect TIGIT level on peripheral blood CD3+ T cells of PBC patients and healthy controls. TIGIT expression in PBC tissues was detected by immunohistochemistry (IHC) and immunofluorescence staining. TCGA database showed that compared with adjacent tissues, TIGIT was significantly upregulated in tumor tissues. High TIGIT expression was positively correlated with tumor stage and negatively correlated with recurrence free survival (RFS) and overall survival (OS). TIGIT level in BC cell lines, peripheral blood and tumor tissues of PBC patients was significantly higher than that of control (P < 0.05). TIGIT level was correlated with age (P < 0.05), rather than tumor size, pathological type, lymph node metastasis, ER, PR, HER-2, and P53. ROC curve showed that the optimal critical value of peripheral blood TIGIT for BC screening was 23.38%. Postoperative TIGIT level in peripheral blood was significantly decreased compared to the preoperative TIGIT level (P < 0.05). TIGIT was upregulated in PBC and was correlated with age. It may be a potential target for the diagnosis and immunotherapy of PBC.

Integrated bioinformatic analysis and cell line experiments reveal the significant role of the novel immune checkpoint TIGIT in kidney renal clear cell carcinoma.

T cell immunoglobulin and ITIM domain (TIGIT) is a widely concerned immune checkpoint, which plays an essential role in immunosuppression and immune evasion. However, the role of TIGIT in normal organ tissues and renal clear cell carcinoma is unclear. We aim to identify the critical role of TIGIT in renal clear cell carcinoma and find potential targeted TIGIT drugs. Data retrieved from the GTEX database and TCGA database was used to investigate the expression of TIGIT in normal whole-body tissues and abnormal pan-cancer, then the transcriptome atlas of patients with kidney renal clear cell carcinoma (KIRC) in the TCGA database were applied to distinguish the TIGIT related features, including differential expression status, prognostic value, immune infiltration, co-expression, and drug response of sunitinib an anti-PD1/CTLA4 immunotherapy in KIRC. Furthermore, we constructed a gene-drug network to discover a potential drug targeting TIGIT and verified it by performing molecular docking. Finally, we conducted real-time polymerase chain reaction (PCR) and assays for Transwell migration and CCK-8 to explore the potential roles of TIGIT. TIGIT showed a moderate expression in normal kidney tissues and was confirmed as an essential prognostic factor that was significantly higher expressed in KIRC tissues, and high expression of TIGIT is associated with poor OS, PFS, and DSS in KIRC. Also, the expression of TIGIT was closely associated with the pathological characteristics of the tumor, high expression of TIGIT in KIRC was observed with several critical functions or pathways such as apoptosis, BCR signaling, TCR signaling etal. Moreover, the expression of TIGIT showed a strong positive correlation with infiltration of CD8+ T cells and Tregs and a positive correlation with the drug sensitivity of sunitinib simultaneously. Further Tide ips score analysis and submap analysis reveal that patients with high TIGIT expression significantly show a better response to anti-PD1 immunotherapy. Following this, we discovered Selumetinib and PD0325901 as potential drugs targeting TIGIT and verified the interaction between these two drugs and TIGIT protein by molecular docking. Finally, we verified the essential role of TIGIT in the proliferation and migration functions by using KIRC cell lines. TIGIT plays an essential role in tumorigenesis and progression in KIRC. High expression of TIGIT results in poor survival of KIRC and high drug sensitivity to sunitinib. Besides, Selumetinib and PD0325901 may be potential drugs targeting TIGIT, and combined therapy of anti-TIGIT and other treatments show great potential in treating KIRC.

The altering cellular components and function in tumor microenvironment during remissive and relapsed stages of anti-CD19 CAR T-cell treated lymphoma mice.

Anti-CD19 chimeric antigen receptor (CAR) T cells represent a highly promising strategy for B-cell malignancies. Despite the inspiring initial achievement, remission in a notable fraction of subjects is short-lived, and relapse remains a major challenge. Tumor microenvironment (TME) was proved to be aroused by CAR T cells; however, little is known about the dynamic characteristics of cellular components in TME especially during the different phases of disease after anti-CD19 CAR T-cell treatment. We took advantage of an immunocompetent model receiving syngeneic A20 lymphoma cells to dissect the changes in TME with or without CAR T-cell injection. We found that anti-CD19 CAR T-cell treatment attenuated the symptoms of lymphoma and significantly prolonged mice survival through eradicating systemic CD19+ cells. Increased myeloid subsets, including CD11c+ DCs and F4/80+ macrophages with higher MHC II and CD80 expression in bone marrow, spleen, and liver, were detected when mice reached remission after anti-CD19 CAR T treatment. Compared to mice without anti-CD19 CAR T administration, intrinsic T cells were triggered to produce more IFN-γ and TNF-α. However, some lymphoma mice relapsed by day 42 after therapy, which coincided with CAR T-cell recession, decreased myeloid cell activation and increased Treg cells. Elevated intrinsic T cells with high PD-1 and TIGIT exhaust signatures and attenuated cytotoxicity in TME were associated with the late-stage relapse of CAR T-cell treatment. In summary, the cellular compositions of TME as allies of CAR T cells may contribute to the anti-tumor efficacy at the initial stage, whereas anti-CD19 CAR T-cell disappearance and host response immunosuppression may work together to cause lymphoma relapse after an initial, near-complete elimination phase.

Preliminary Exploration of the Clinical Features and Immunological Correlation between TIGIT and Esophageal Squamous Cell Carcinoma

Objective: To analyze the relationship between TIGIT and clinical features of Esophageal Squamous Cell Carcinoma, we use transcriptomic data from the TCGA database, and to investigate the relationship between TIGIT and the immune microenvironment of Esophageal Squamous Cell Carcinoma, to provide a basis for improving the treatment strategy and prognosis of patients with Esophageal Squamous Cell Carcinoma. Methods: RNA sequencing data and clinical data corresponding to cancer tissues were obtained from the TCGA database for Esophageal carcinoma, Esophageal Squamous Cell Carcinoma tissues, and paraneoplastic tissues; then we analyzed the differences in TIGIT expression in Esophageal carcinoma, Esophageal Squamous Cell Carcinoma, and normal esophageal tissues; then we analyzed the relationship between TIGIT expression levels and overall survival in Esophageal Squamous Cell Carcinoma; finally, we explored the relationship between TIGIT expression levels and overall survival in Esophageal Squamous Cell Carcinoma. We investigated the relationship between TIGIT and the tumor immune microenvironment of Esophageal Squamous Cell Carcinoma by tumor immune infiltration and functional enrichment analysis. Results: Our study revealed that TIGIT was highly expressed in Esophageal Squamous Cell Carcinoma, and patients with high TIGIT expression had worse overall survival. We also found a close relationship between TIGIT expression levels and the immune microenvironment of Esophageal Squamous Cell Carcinoma, with high TIGIT expression positively correlated with multiple immune cells. Conclusion: Our study demonstrates that TIGIT is associated with Esophageal Squamous Cell Carcinoma malignancy and is closely linked to the immune microenvironment. Furthermore, high expression of TIGIT often predicts poorer clinical features.

Correlation of the TIGIT-PVR immune checkpoint axis with clinicopathological features in triple-negative breast cancer.

T cell immunoreceptor with Ig and ITIM domains (TIGIT) interacts with poliovirus receptor (PVR) to contribute to cancer immune escape. Recently, TIGIT and PVR have been identified as promising immunotherapy targets. Their gene expression is upregulated in many solid tumors, but their protein expression level is not well documented, particularly in triple negative breast cancer (TNBC), the breast cancer subtype that most benefit from immunotherapy. TIGIT and PVR expression levels were assessed by immunohistochemistry in 243 surgically resected localized TNBC and then their relationship with clinical-pathological features and clinical outcome was analyzed. TIGIT expression was observed in immune cells from the tumor microenvironment, whereas PVR was mainly expressed by tumor cells. High TIGIT expression was significantly associated with age (p=0.010), histological grade (p=0.014), non-lobular histology (p=0.024), adjuvant chemotherapy (p=0.006), and various immune cell populations (tumor infiltrating lymphocytes (TILs), CD3+, CD8+, PD-1+ cells; all p<0.0001), PD-L1+ tumor cells (p<0.0001), and PD-L1+ stromal cells (p=0.003). Infiltration by TIGIT+ cells tended to be higher in non-molecular apocrine tumors (p=0.088). PVR was significantly associated with histological grade (p<0.0001), the basal-like (p=0.003) and non-molecular apocrine phenotypes (p=0.039), high TILs infiltration (p=0.011), CD3+ (p=0.002), CD8+ (p=0.024) T cells, and PD-L1 expression in tumor (p=0.003) and stromal cells (p=0.001). In univariate analysis, only known prognostic factors (age, tumor size, lymph node status, adjuvant chemotherapy, TILs and CD3+ T-cell infiltrate) were significantly associated with relapse-free survival (RFS) and overall survival. High TIGIT and PVR expression levels tended to be associated with longer RFS (p=0.079 and 0.045, respectively). The analysis that included only non-molecular apocrine TNBC revealed longer RFS for tumors that strongly expressed TIGIT or PVR (p=0.025 for TIGIT and 0.032 for PVR). These results indicated that in TNBC, TIGIT+ cells can easily interact with PVR to exert their inhibitory effects. Their wide expression in TNBC and their association with other immune checkpoint components suggest the therapeutic interest of the TIGIT-PVR axis.

PVR/TIGIT and PD-L1/PD-1 expression predicts survival and enlightens combined immunotherapy in lung squamous cell carcinoma

PVR/TIGIT and PD-L1/PD-1 axes play essential roles in tumor immune evasion and could be potential targets for combined immunotherapy. We aimed to evaluate the expression status of the above-mentioned immune markers in lung squamous cell carcinoma (LUSC), and investigate their survival impact and relevance with the immune microenvironment and clinicopathological features. We retrospectively collected specimens from 190 LUSC patients, who underwent pulmonary surgeries, and we performed immunohistochemistry assays of PVR, TIGIT, PD-L1, PD-1 and CD8. In our cohort, the positive rate of PVR was 85.8%, which was much higher than the positive rate of PD-L1 at 26.8%. A total of 32 (16.8%) patients demonstrated co-expression of PVR/PD-L1. High TIGIT density was correlated with positive PD-L1 expression, high PD-1 density, and high CD8 density (PD-L1, P=0.033; PD-1, P<0.001; CD8, P<0.001), and positive PVR expression was correlated with positive PD-L1 expression (P=0.046). High TIGIT density and high PVR/TIGIT expression were correlated with advanced TNM stage (TIGIT density, P=0.020; PVR/TIGIT expression, P=0.041). Patients with positive PVR expression, high TIGIT density, high PVR/TIGIT expression and PVR/PD-L1 co-expression exhibited a significantly worse prognosis (PVR, P=0.038; TIGIT, P=0.027; PVR/TIGIT, P=0.014; PVR/PD-L1, P=0.018). Multivariate analysis demonstrated that PVR/PD-L1 co-expression (Hazard ratio [HR], 1.756, 95% CI, 1.152-2.676, P=0.009) was an independent prognostic factor in LUSC patients. In conclusion, we demonstrated the expression status of PVR/TIGIT and PD-L1/PD-1 in LUSC. PVR/PD-L1 co-expression was an independent prognostic factor in LUSC patients and may serve as a potential predictive biomarker for dual-targeting immunotherapy.

Clinical significance of signal regulatory protein alpha and T cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibition motif domain expression in undifferentiated pleomorphic sarcoma.

Undifferentiated pleomorphic sarcoma (UPS) is associated with poor prognosis. Recently, signal regulatory protein alpha (SIRPα), which is the immune checkpoint of macrophages, and T cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibition motif domains (TIGIT), which is the immune checkpoint of T cells and natural killer cells, have been considered as potential targets for cancer immunotherapy. This study aimed to assess the value of SIRPα and TIGIT as prognostic factors of UPS. The cBio Cancer Genomics Portal was used to analyze mRNA expression data of 50 UPS cases in the Cancer Genome Atlas. We retrieved 49 UPS cases and performed immunohistochemistry (IHC) to detect programmed death ligand 1 (PD-L1), SIRPα, CD68, CD163, TIGIT, CD155, and CD8. SIRPα was positively associated with CD163 (Pearson's r = 0.51, p = 0.0002) as per open access data and IHC of the cohort (p = 0.002), which revealed that SIRPα-positive macrophage infiltration was higher in UPS cells with ≥ 1% PD-L1 expression than that in UPS cells with < 1% PD-L1 expression (p = 0.047). TIGIT was positively correlated with PD-L1 (r = 0.54, p < 0.0001) and CD8A (r = 0.98, p < 0.0001). In 35 of 49 cases, IHC revealed high levels of TIGIT expression on tumor cells. Furthermore, TIGIT expression on tumor cells was negatively correlated with CD155-positive (p = 0.0144) and CD8-positive (p = 0.0487) cell infiltration. Survival analysis showed that the high degree of SIRPα-positive macrophage infiltration was associated with poor overall survival and metastasis (p < 0.0001, p = 0.0006, respectively). SIRPα-positive macrophages infiltrated UPS cells, which predicted poor prognosis. High TIGIT expression on tumor cells was associated with decreased levels of tumor-infiltrating macrophages in UPS.

Blocking TIGIT/CD155 signalling reverses CD8+ T cell exhaustion and enhances the antitumor activity in cervical cancer

ObjectiveTIGIT/CD155 has attracted widespread attention as a new immune checkpoint and a potential target for cancer immunotherapy. In our study, we evaluated the role of TIGIT/CD155 checkpoints in the progression of cervical cancer.MethodsThe expression of CD155 and TIGIT in cervical cancer tissues was detected using flow cytometry, immunohistochemistry (IHC) and gene expression profiling. In vivo and in vitro experiments have proven that blocking TIGIT/CD155 restores the ability of CD8+ T cells to produce cytokines. Changes in the NF-κB and ERK pathways were detected using western blotting (WB) after blocking TIGIT/CD155 signalling.ResultsTIGIT expression was elevated in patients with cervical cancer. High TIGIT expression in CD8+ T lymphocytes from patients with cervical cancer promotes the exhaustion of CD8+ T lymphocytes. In addition, CD155 is expressed at high levels in cervical cancer tissues and is negatively correlated with the level of infiltrating CD8+ T cells. We found that TIGIT, upon binding to CD155 and being phosphorylated, inhibited NF-κB and ERK activation by recruiting SHIP-1, resulting in the downregulation of cytokine production. Blocking TIGIT in activated CD8+ T cells attenuates the inhibitory effect of SHIP-1 on CD8+ T cells and enhances the activation of NF-κB and ERK. In vivo and in vitro experiments have proven that blocking TIGIT/CD155 restores the ability of CD8+ T cells to produce cytokines. Injecting the blocking antibody TIGIT in vivo inhibits tumour growth and enhances CD8+ T lymphocyte function. Treatment with a combination of TIGIT and PD-1 inhibitors further increases the efficacy of the TIGIT blocking antibody.ConclusionsOur research shows that TIGIT/CD155 is a potential therapeutic target for cervical cancer.

TIGIT/CD47 dual high expression predicts prognosis and is associated with immunotherapy response in lung squamous cell carcinoma.

BackgroundRecent studies indicated that T cell immunoreceptor with immunoglobulin and ITIM domains (TIGIT) and cluster of differentiation 47 (CD47) have emerged as new potential immunotherapy targets. However, the roles of TIGIT and CD47 in lung squamous cell carcinoma (LUSC) have not been fully illustrated.MethodsThe specimens and clinicopathological information from 190 LUSC patients who underwent surgeries in our center were retrospectively collected. Immunohistochemical staining for TIGIT and CD47 was conducted. Transcriptional and clinical data of 479 LUSC were downloaded from The Cancer Genome Atlas (TCGA).ResultsIn the TCGA LUSC cohort, 142 (29.6%) cases were TIGIT/CD47 dual high expression at RNA level. The expression levels of TIGIT and CD47 were significantly correlated (p < 0.001). The proportions of patients with high TIGIT expression (p = 0.001) and high TIGIT/CD47 dual high expression (p = 0.049) were both higher in female cases. Advanced TNM stage (p = 0.006) and TIGIT/CD47 dual high expression (p = 0.047) were independent prognostic factors for LUSC. In the 190 LUSC cohort of our center, 75 (39.5%) cases were TIGIT/CD47 dual high expression at protein level. Cross‐table analysis showed a correlation between TIGIT and CD47 expression. Older age (p = 0.001), advanced TNM stage (p < 0.001) and TIGIT/CD47 dual high expression (p = 0.046) were independent prognostic factors in our cohort.ConclusionWe found that TIGIT and CD47 dual high expression was associated with poor prognosis in LUSC. We speculated that patients with dual high expression of CD47/TIGIT might be suitable for new target immunotherapy in the future.

DNA methylation regulates TIGIT expression within the melanoma microenvironment, is prognostic for overall survival, and predicts progression-free survival in patients treated with anti-PD-1 immunotherapy

BackgroundTIGIT is an immune checkpoint under investigation as therapeutic target. Understanding the regulation of TIGIT on an epigenetic level might support the development of companion biomarkers.MethodsWe correlated TIGIT DNA methylation of single CpG sites with gene expression, signatures of immune infiltrates and interferon-γ, and survival in melanoma. We further analyzed methylation levels in immune cell subsets, melanocyte and melanoma cell lines. TIGIT expression patterns within components of the melanoma microenvironment were analyzed by single cell sequencing. We used quantitative methylation-specific PCR, flow cytometry, and immunohistochemistry for correlations between expression and methylation and to assess the effect of pharmacological demethylation of melanoma cells treated with 5‐aza‐2‐deoxycytidine (decitabine). Finally, we investigated the association of patients’ survival with TIGIT mRNA and methylation.ResultsDepending on the sequence context of the analyzed CpG site, we found a cell type-specific TIGIT gene locus methylation pattern and significant correlations of TIGIT methylation with mRNA expression, an interferon γ signature, and distinct immune cell infiltrates, including TIGIT+ lymphocytes. We detected a melanoma cell-intrinsic TIGIT protein expression. Pharmacological demethylation of the A375 melanoma cell line led to a constitutive TIGIT expression. Low promoter flank methylation and high mRNA expression was associated with patients’ prognosis and predicted progression-free survival in patients treated with anti-PD-1 immunotherapy. A high TIGIT+ lymphocyte score was associated with better progression-free survival under anti-PD-1 immunotherapy.ConclusionsOur data demonstrate an epigenetic regulation of TIGIT expression via DNA methylation within the melanoma microenvironment. TIGIT DNA methylation and expression may serve as predictive biomarkers in the context of immunotherapies in melanoma.