CTLA-4 silencing could promote anti-tumor effects in hepatocellular.

Preclinical and clinical research showed that immune checkpoint blockade provides beneficial effects for many patients with liver cancer. This study aimed to assess the effect of CTLA-4-specific siRNA on the proliferation, cell cycle, migration, and apoptosis of HePG2 cells. Transfection of siRNA was performed by electroporation. The viability of cells was determined through MTT assay. Flow cytometry was performed to investigate the cell cycle and apoptosis rate, and the wound-healing assay was used to determine HepG2 cells migration. The expression levels of CTLA-4, c-Myc, Ki-67, BCL-2, BAX, caspase-9 (CAS9), and MMP-2,9,13 were measured by qRT-PCR. Transfection of specific CTLA-4-siRNA significantly inhibited the expression of the CTLA-4 gene. Also, our results revealed that CTLA-4 silencing diminished the proliferation and migration as well as induced the apoptosis of HePG2 cells. CTLA-4-siRNA transfection induced the cell cycle arrest in G2 phase. Moreover, CTLA-4-siRNA transfection reduced the expression levels of c-Myc, Ki-67, BCL-2, MMP-2,9,13, and elevated the expression levels of BAX and caspase-9. Our results suggest that silencing CTLA-4 through specific siRNA may be a promising strategy for future therapeutic interventions for treating liver cancer.

A phase Ib randomized multicenter trial of isolated hepatic perfusion in combination with ipilimumab and nivolumab for uveal melanoma metastases (SCANDIUM II trial).

BACKGROUND: Uveal melanoma (UM) is a rare malignancy where 50% of patients develop metastatic disease primarily affecting the liver. Approximately 40% of patients with metastatic UM respond to one-time isolated hepatic perfusion (IHP) with high-dose melphalan. This phase I trial investigates the safety and clinical efficacy of IHP combined with ipilimumab (IPI) and nivolumab (NIVO). PATIENTS AND METHODS: Immunotherapy-naïve patients were randomized in this phase I trial to receive either IHP followed by IPI 3 mg/kg and NIVO 1 mg/kg (IPI3/NIVO1) for four cycles (post-operative arm), or one cycle of preoperative IPI3/NIVO1, IHP and then three cycles of IPI3/NIVO1 (pre-post-operative arm), followed by maintenance therapy with NIVO 480 mg for 1 year. RESULTS: Eighteen patients were enrolled and randomized. Three patients did not undergo IHP as planned. In total, 11/18 patients (6 in the post-operative arm and 5 in the pre-post-operative arm) did not complete the planned four cycles of IPI3/NIVO1. Toxicity to IHP was similar in both groups, but the number of immune-related adverse events (AEs) was higher in the pre-post-operative arm. Among assessable patients, overall response rate was 57% in the post-operative arm (4/7) and 22% in the pre-post-operative arm (2/9). CONCLUSIONS: Combination therapy with IHP and IPI3/NIVO1 was associated with severe AEs. The efficacy of this combination is encouraging with high response rates. One cycle of preoperative IPI/NIVO before IHP did not show potential benefits in terms of safety or efficacy.

Effects of IL-6, JAK, TNF inhibitors, and CTLA4-Ig on knee symptoms in patients with rheumatoid arthritis.

This study aims to identify factors influencing the alleviation of knee joint symptoms in patients with rheumatoid arthritis treated with biologic or target synthetic disease-modifying antirheumatic drugs (b/tsDMARDs). Among 2321 patients who started b/tsDMARDs between 2010 and 2023, we focused on 295 patients who had knee swelling or tenderness at the initiation of b/tsDMARDs and continued b/tsDMARDs at least 3 months, with recorded knee symptoms 6 months later. Symptom relief after 6 months was 78.2% for interleukin 6 (IL-6) inhibitors, 68.6% for Janus kinase (JAK) inhibitors, 65.8% for tumor necrosis factor (TNF) inhibitors, and 57.6% for cytotoxic T lymphocyte-associated antigen-4-Ig (CTLA4-Ig). The initial use of b/tsDMARDs and the use of IL-6 inhibitors in comparison to CTLA4-Ig emerged as a significant factor associated with the improvement of knee joint symptoms. Among 141 patients who underwent knee radiography at baseline and two years later, the deterioration in knee joint radiographs was 7.7% for IL-6 inhibitors, 6.3% for JAK inhibitors, 21.9% for TNF inhibitors, and 25.9% for CTLA4-Ig. The use of IL-6 inhibitors was a significant factor associated with the improvement of knee joint symptoms and the inhibition of joint destruction compared to CTLA4-Ig.

Immune checkpoint inhibitor-associated new-onset hypophysitis: a retrospective analysis using the FAERS.

BACKGROUND: Our study aimed to investigate the prevalence and demographic characteristics of immune checkpoint inhibitor-associated hypophysitis (ICI-hypophysitis) using data from the FAERS, and the risk factors of prognosis were explored. METHODS: In this retrospective study, all cases of newly-diagnosed hypophysitis associated with FDA approved ICIs from 1st January 2007 to 31st December 2022 were accumulated using FAERS. Demographic data including age, sex, body weight, the prognosis of cases, and other co-occurred endocrinopathies induced by ICIs were analyzed and compared between different subgroups of immunotherapy. RESULTS: The reporting frequency of ICI-hypophysitis was 1.46% (2343/160089). Patients on the combination therapy had higher risk of hypophysitis reporting, followed by anti-CTLA-4 agent compared with other monotherapies (p < 0.001). Male subjects displayed higher reporting risk of ICI-hypophysitis (p = 0.015). Patients on anti-PD-1 therapy or the combination therapy showed higher occurrence rate of type 1 diabetes (anti-PD-1 vs. anti-PD-L1 vs. anti-CTLA-4 vs. combination therapy, 4.2% vs. 0.7% vs. 0.3% vs. 8.4%, p < 0.001). The occurrence rate of new-onset thyroid diseases in patients receiving combination therapy was higher than anti-PD-1 monotherapy (12.3% vs. 8.4%, p = 0.010). Elder age, lung cancer, and renal cancer emerged to be positively associated with severe clinical outcomes [>65 years, OR 1.042, 95%CI (1.022-1.063), p < 0.001; lung cancer, OR 1.400, 95%CI (1.019-1.923), p = 0.038; renal cancer, OR 1.667, 95%CI (1.153-2.412), p = 0.007]. Anti-CTLA-4 monotherapy was discovered to be a protective factor of severe outcomes [OR 0.433, 95%CI (0.335-0.558), p < 0.001]. Female sex and co-occurrence of ICI-related diabetes exhibited lower risk of death [female, OR 0.571, 95%CI (0.361-0.903), p = 0.017; diabetes, OR 0.090, 95%CI (0.016-0.524), p = 0.007]. CONCLUSIONS: ICI-induced hypophysitis is male-predominant irAE, most commonly seen in patients on anti-CTLA-4 mono- or combination therapy. Awareness among clinicians is critical when patients with elder age, lung or renal cancer develop hypophysitis, which indicates poor clinical outcomes. Female sex, anti-CTLA-4 monotherapy and co-occurrence of ICI-related diabetes are protective risk factors for poor prognosis.

Cardiovascular toxicity with CTLA-4 inhibitors in cancer patients: A meta-analysis.

Background: With the emergence of cytotoxic T lymphocyte-associated protein-4 (CTLA-4) inhibitors, the outcomes of patients with malignant tumors have improved significantly. However, the incidence of cardiovascular adverse events has also increased, which can affect tumor treatment. In this study, we evaluated the incidence and severity of adverse cardiovascular events caused by CTLA-4 inhibitors by analyzing reported trials that involved CTLA-4 inhibitor therapy. Methods: Randomized clinical trials published in English from January 1, 2013, to November 30, 2022, were searched using the Cochrane Library and PubMed databases. All included trials examined all grade and grades 3-5 cardiac and vascular adverse events. These involved comparisons of CTLA-4 inhibitors to placebo, CTLA-4 inhibitors plus chemotherapy to chemotherapy alone, CTLA-4 inhibitors combined with PD-1/PD-L1 inhibitors to PD-1/PD-L1 inhibitors alone, and CTLA-4 inhibitors plus target agent to PD-1/PD-L1 inhibitors plus target agent. The odds ratio (OR) and corresponding 95% confidence intervals (CIs) were calculated using the Mantel-Haenszel method. Results: Overall, 20 trials were included. CTLA-4 inhibitors significantly increased the incidence of all-grade cardiovascular toxicity (OR = 1.33, 95% CI: 1.00-1.75, p = 0.05). The incidence of all-grade cardiovascular toxicity increased in malignant tumor patients who received single-agent CTLA-4 inhibitors (OR = 1.73, 95% CI: 1.13-2.65, p = 0.01), as well as the incidence rate of grades 3-5 cardiovascular adverse events (OR = 2.00, 95% CI: 1.08-3.70, p = 0.03). Compared with the non-CTLA-4 inhibitor group, CTLA-4 inhibitors plus chemotherapy, PD-1/PD-L1 inhibitors, or target agent did not significantly affect the incidence of cardiac and vascular toxicity. The incidence of grades 3-5 cardiac failure, hypertension, pericardial effusion, myocarditis, and atrial fibrillation were much higher among patients exposed to CTLA-4 inhibitor, but the data were not statistically significant. Conclusion: Our findings suggest that the incidence rate of all cardiovascular toxicity and severe cardiovascular toxicity increased in patients who were administered CTLA-4 inhibitors. In addition, the risk of serious cardiovascular toxic events was independent of the type of adverse event. From these results, physicians should assess the benefits and risks of CTLA-4 inhibitors when treating malignancies.

Immunotherapy Based on Immune Checkpoint Molecules and Immune Checkpoint Inhibitors in Gastric Cancer-Narrative Review.

Due to its rapid progression to advanced stages and highly metastatic properties, gastric cancer (GC) is one of the most aggressive malignancies and the fourth leading cause of cancer-related deaths worldwide. The metastatic process includes local invasion, metastasis initiation, migration with colonisation at distant sites, and evasion of the immune response. Tumour growth involves the activation of inhibitory signals associated with the immune response, also known as immune checkpoints, including PD-1/PD-L1 (programmed death 1/programmed death ligand 1), CTLA-4 (cytotoxic T cell antigen 4), TIGIT (T cell immunoreceptor with Ig and ITIM domains), and others. Immune checkpoint molecules (ICPMs) are proteins that modulate the innate and adaptive immune responses. While their expression is prominent on immune cells, mainly antigen-presenting cells (APC) and other types of cells, they are also expressed on tumour cells. The engagement of the receptor by the ligand is crucial for inhibiting or stimulating the immune cell, which is an extremely important aspect of cancer immunotherapy. This narrative review explores immunotherapy, focusing on ICPMs and immune checkpoint inhibitors in GC. We also summarise the current clinical trials that are evaluating ICPMs as a target for GC treatment.

Evaluating the immunologically "cold" tumor microenvironment after treatment with immune checkpoint inhibitors utilizing PET imaging of CD4 + and CD8 + T cells in breast cancer mouse models.

BACKGROUND: Immune-positron emission tomography (PET) imaging with tracers that target CD8 and granzyme B has shown promise in predicting the therapeutic response following immune checkpoint blockade (ICB) in immunologically "hot" tumors. However, immune dynamics in the low T-cell infiltrating "cold" tumor immune microenvironment during ICB remain poorly understood. This study uses molecular imaging to evaluate changes in CD4 + T cells and CD8 + T cells during ICB in breast cancer models and examines biomarkers of response. METHODS: [89Zr]Zr-DFO-CD4 and [89Zr]Zr-DFO-CD8 radiotracers were used to quantify changes in intratumoral and splenic CD4 T cells and CD8 T cells in response to ICB treatment in 4T1 and MMTV-HER2 mouse models, which represent immunologically "cold" tumors. A correlation between PET quantification metrics and long-term anti-tumor response was observed. Further biological validation was obtained by autoradiography and immunofluorescence. RESULTS: Following ICB treatment, an increase in the CD8-specific PET signal was observed within 6 days, and an increase in the CD4-specific PET signal was observed within 2 days in tumors that eventually responded to immunotherapy, while no significant differences in CD4 or CD8 were found at the baseline of treatment that differentiated responders from nonresponders. Furthermore, mice whose tumors responded to ICB had a lower CD8 PET signal in the spleen and a higher CD4 PET signal in the spleen compared to non-responders. Intratumoral spatial heterogeneity of the CD8 and CD4-specific PET signals was lower in responders compared to non-responders. Finally, PET imaging, autoradiography, and immunofluorescence signals were correlated when comparing in vivo imaging to ex vivo validations. CONCLUSIONS: CD4- and CD8-specific immuno-PET imaging can be used to characterize the in vivo distribution of CD4 + and CD8 + T cells in response to immune checkpoint blockade. Imaging metrics that describe the overall levels and distribution of CD8 + T cells and CD4 + T cells can provide insight into immunological alterations, predict biomarkers of response to immunotherapy, and guide clinical decision-making in those tumors where the kinetics of the response differ.

A Review of Immunotherapy in Non-Small-Cell Lung Cancer.

Cancer immunotherapy in the form of immune checkpoint inhibitors has led to a dramatic increase in the survival of patients with lung cancer across all stages. Over the past decade, the field has experienced rapid maturation; however, several challenges continue to complicate patient management. This review aims to highlight the data that led to this dramatic shift in practice as well as to focus on key challenges. These include determining the optimal therapy duration, managing frail patients or those with brain metastases, addressing the challenges posed by immune-related adverse events, and defining the various patterns of clinical and radiological responses to immunotherapy.

Post-immunotherapy CTLA-4 Ig treatment improves antitumor efficacy.

Immune checkpoint therapies (ICT) improve overall survival of patients with cancer but may cause immune-related adverse events (irAEs) such as myocarditis. Cytotoxic T lymphocyte-associated antigen 4 immunoglobulin fusion protein (CTLA-4 Ig), an inhibitor of T cell costimulation through CD28, reverses irAEs in animal models. However, concerns exist about potentially compromising antitumor response of ICT. In mouse tumor models, we administered CTLA-4 Ig 1) concomitantly with ICT or 2) after ICT completion. Concomitant treatment reduced antitumor efficacy, while post-ICT administration improved efficacy without affecting frequency and function of CD8 T cells. The improved response was independent of the ICT used, whether CTLA-4 or PD-1 blockade. The frequency of Tregs was significantly decreased with CTLA-4 Ig. The resulting increased CD8/Treg ratio potentially underlies the enhanced efficacy of ICT followed by CTLA-4 Ig. This paradoxical mechanism shows that a CTLA-4 Ig regimen shown to reduce irAE severity does not compromise antitumor efficacy.

CTLA4 genetic variants associated with urothelial bladder cancer susceptibility.

PURPOSE: The study evaluated the relationship between the CTLA4 rs231775 (+49A>G) and rs231779 (+1822C>T) variants and susceptibility, stage, prognosis and response to treatment of the urothelial bladder cancer (UBC). METHODS: A total of 140 patients with UBC and 145 controls were enrolled. The patients were stratified as non-muscle invasive bladder cancer (NMIBC) and muscle invasive bladder cancer (MICB), metastasis, recurrence, low/moderate/high/very high risk. Demographic, anthropometric, epidemiological, and clinical data were obtained from all individuals using a structured questionnaire. The CTLA4 variants were determined using real-time polymerase chain reaction (qPCR) and the genotypes were tested in the allelic, codominant, dominant, recessive, and overdominant genetic models. RESULTS: The UBC patients were older and mostly smokers (P < 0.001), with greater waist circumference, systolic, and diastolic arterial pressure (P = 0.005, P = 0.006, and P < 0.001, respectively) than controls. A protective effect for the UBC was observed among the patients carrying the heterozygote genotypes of the CTLA4 rs231775 [odds ratio (OR = 0.40; 95% confidence interval (CI): 0.160.98, P = 0.045) and rs231779 (OR = 0.35; 95% CI: 0.14-0.87, P = 0.024). R2 Nagelkerke analysis demonstrated that a model with age and smoking added to the CTLA4 rs231775 SNVs explained 77.0% of the susceptibility to UBC and a model with age and smoking added to the CLTA4 rs231779 explained 77.2% of the susceptibility to UBC. CONCLUSION: The CTLA4 rs231775 AG and rs231779 CT heterozygous genotypes in the overdominant model together with age and smoking may be useful as potential biomarkers for the UBC susceptibility.

Differences in IDO1+ dendritic cells and soluble CTLA-4 are associated with differential clinical responses to methotrexate treatment in rheumatoid arthritis.

Objective: Antigen-presenting dendritic cells (DCs) and monocytes play an essential role in rheumatoid arthritis (RA) pathogenesis, however, their tolerogenic potential remains unclear. Herein, the tolerogenic profiles of DCs are characterized in treatment-naïve RA patients to determine their role to inflammatory arthritis management. Methods: Thirty-six treatment-naïve RA patients were enrolled, of which 62% were non-responders to methotrexate (MTX) monotherapy based on disease activity score (DAS) after 6-months of therapy. DC and monocyte subset frequencies, activation (CD40, CD86, CD209 expression), and tolerogenic profile (intracellular indoleamine-2,3-dioxygenase [IDO1] and cytotoxic T lymphocyte antigen 4 [CTLA-4] expression) were examined in the baseline peripheral blood by multicolor flow-cytometry. Soluble CTLA-4 (sCTLA-4) levels in plasma were measured. Results: DC subsets were decreased in RA compared to healthy controls (HC), and the frequency of conventional DCs (cDC) inversely correlated with inflammatory markers and improvement in disease activity. CD141+ cDC1s were the major IDO1-expressing cells. IDO1+cDC1s were reduced in RA patients compared to HC. The baseline frequency of IDO1+cDC1s inversely correlated with improvement in disease activity. CTLA-4 expression in CD1c+ cDC2s and monocytes was lower in RA patients compared to HC. Moreover, MTX-responders had a significantly lower frequency of IDO1+cDC1 cells and higher level of sCTLA-4 in the plasma compared to MTX non-responders. There was a strong predictive association of low IDO1+cDC1 cells, low sCTLA-4 and non-response to MTX. Conclusions: Our findings reveal altered DC and monocytes immunophenotypes that are associated with RA pathology and treatment response. The frequencies of tolerogenic IDO1+cDC1s and the low level of sCTLA-4 are strongly associated with MTX non-responsiveness and therapeutic outcome. These results suggest that investigation of the association IDO1+cDC1 and sCTLA-4 with response to treatment may be more generalizable to other autoimmune diseases.

Advancements in immunotherapy for advanced esophageal squamous cell carcinoma: a comprehensive review of current strategies and future directions.

INTRODUCTION: Esophageal cancer (EC), particularly esophageal squamous cell carcinoma (ESCC), is characterized by high incidence and poor prognosis worldwide, necessitating novel therapeutic approaches like immunotherapy. This review explores the impact of immune checkpoint inhibitors (ICIs) on ESCC, especially focusing on PD-1/PD-L1 and CTLA-4 inhibitors. Our literature search, conducted across databases including PubMed, Web of Science, and EMBASE, from January 2010 to December 2023, aimed at identifying advancements, challenges, and future directions in the use of immunotherapy for ESCC. AREAS COVERED: We provide a detailed analysis of clinical trials evaluating the efficacy of ICIs as monotherapy and in combination with chemotherapy, radiotherapy, and targeted therapy for locally advanced ESCC. Our findings highlight the significant survival benefits offered by ICIs, albeit with varying efficacy across patient populations, emphasizing the need for precise biomarkers to tailor treatment strategies. EXPERT OPINION: The integration of immunotherapy into the ESCC treatment paradigm represents a significant shift, improving survival outcomes. Future research should focus on optimizing combination therapies and novel immunotherapeutic agents, incorporating genetic and tumor microenvironment analyses to enhance patient selection and treatment efficacy.

Checkpoint Inhibitors in Dogs: Are We There Yet?

Immune checkpoint inhibitors (ICI) have revolutionised cancer treatment in people. Immune checkpoints are important regulators of the body's reaction to immunological stimuli. The most studied immune checkpoint molecules are programmed death (PD-1) with its ligand (PD-L1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) with its ligands CD80 (B7-1) and CD86 (B7-2). Certain tumours can evade immunosurveillance by activating these immunological checkpoint targets. These proteins are often upregulated in cancer cells and tumour-infiltrating lymphocytes, allowing cancer cells to evade immune surveillance and promote tumour growth. By blocking inhibitory checkpoints, ICI can help restore the immune system to effectively fight cancer. Several studies have investigated the expression of these and other immune checkpoints in human cancers and have shown their potential as therapeutic targets. In recent years, there has been growing interest in studying the expression of immune checkpoints in dogs with cancer, and a few small clinical trials with ICI have already been performed on these species. Emerging studies in veterinary oncology are centred around developing and validating canine-targeted antibodies. Among ICIs, anti-PD-1 and anti-PD-L1 treatments stand out as the most promising, mirroring the success in human medicine over the past decade. Nevertheless, the efficacy of caninized antibodies remains suboptimal, especially for canine oral melanoma. To enhance the utilisation of ICIs, the identification of predictive biomarkers for treatment response and the thorough screening of individual tumours are crucial. Such endeavours hold promise for advancing personalised medicine within veterinary practice, thereby improving treatment outcomes. This article aims to review the current research literature about the expression of immune checkpoints in canine cancer and the current results of ICI treatment in dogs.

Immune Checkpoint Inhibitors in Hepatocellular Carcinoma and Their Hepatic-Related Side Effects: A Review.

Primary liver cancer is one of the leading causes of cancer mortality worldwide, with hepatocellular carcinoma (HCC) being the most prevalent type of liver cancer. The prognosis of patients with advanced, unresectable HCC has historically been poor. However, with the emergence of immunotherapy, specifically immune checkpoint inhibitors (ICIs), there is reason for optimism. Nevertheless, ICIs do not come without risk, especially when administered in patients with HCC, given their potential underlying poor hepatic reserve. Given their novelty in the management of HCC, there are few studies to date specifically investigating ICI-related side effects on the liver in patients with underlying HCC. This review will serve as a guide for clinicians on ICIs' role in the management of HCC and their potential side effect profile. There will be a discussion on ICI-related hepatotoxicity, the potential for hepatitis B and C reactivation with ICI use, the potential for the development of autoimmune hepatitis with ICI use, and the risk of gastrointestinal bleeding with ICI use. As ICIs become more commonplace as a treatment option in patients with advanced HCC, it is imperative that clinicians not only understand the mechanism of action of such agents but also understand and are able to identify hepatic-related side effects.

Targeting the dynamic transcriptional landscape of Treg subpopulations in pancreatic ductal adenocarcinoma: Insights from single-cell RNA sequencing analysis with a focus on CTLA4 and TIGIT.

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy that represents a significant challenge in cancer research and clinical management. In this study, we reanalyzed a published single-cell RNA sequencing (scRNA-seq) dataset from PDAC and adjacent tissues to investigate the heterogeneity of tumor and normal tissue, specifically focusing on the regulatory T cells (Tregs) and their interactions with other cells in the tumor microenvironment (TME). Treg cells were identified and clustered into natural Tregs (nTreg) and induced Tregs (iTreg) based on the expression of specific genes. It was found that the number of iTregs was higher in the tumor than in healthy tissues, while the number of n Tregs was higher in healthy tissues. Differential gene expression analysis was performed, and biological process analysis revealed that the Tregs in PDAC were mostly involved in protein targeting and translation pathways. In addition, ligand-receptor pairs between Tregs and other cell types were identified, and the critical communication pathways between Tregs and endothelial and ductal cells were revealed, which could potentially contribute to the immunosuppressive TME of PDAC. These findings provide insights into the role of Tregs in PDAC and their interactions with other cell types in the TME, highlighting potential targets for immunotherapy, such as the inhibitory immune checkpoint receptors CTLA4 and TIGIT, which are known to be expressed on Tregs and have been shown to play a role in suppressing anti-tumor immune responses.

Increased inhibitory surface marker PD-1 expression in CD4+T cells and Th2+T cells in allergen-specific immunotherapy.

Recent evidence has shown that T cell exhaustion is implicated in Allergen-specific Immunotherapy (AIT). However, how T cell exhaustion plays a role in AIT is far from clear. Our study aimed to investigate T cell exhaustion associated with allergen exposure during AIT in mice. Ovalbumin (OVA) - sensitized C57BL/6J asthma mouse and AIT mouse models were constructed. Quantitative real-time PCR (qRTPCR) and flow cytometry were used to monitor the occurrence of local and systemic CD4+ T cells and Th2+T cells exhaustion in OVA-sensitized mice. The inhibitory surface marker programmed cell death protein 1 (PD-1) on CD4+ T cells and Th2+T cells was significantly upregulated in AIT mice compared with asthmatic and control mice. The level of PD-1 on the surface of CD4+T cells of asthma mice was significantly higher than that of control mice. The inhibitory surface marker cytotoxic T lymphocyte-associated protein 4 (CTLA-4) on CD4+ T cells and Th2+T cells showed no significant difference between the AIT, asthma and control mice. Collectively, our study indicated that the expression of PD-1 on CD4+ T cells and Th2+T cells was increased in AIT. Allergen exposure promotes the expression of PD-1 on the surface of CD4+ T cells. T cell exhaustion plays an important role in AIT.

Role of CTLA4 and pSTAT3 Immunostaining in Prognosis and Treatment of the Colorectal Carcinoma.

Background & Objective: Colorectal carcinoma (CRC) is the third leading cause of cancer-caused death worldwide and constitutes about 6.48% of all malignancies in Egypt. Studying the molecular profile of CRC is essential for developing targeted therapies. STAT3 and CTLA4 expression are considered as molecular abnormalities involved in the CRC progression and chemo-resistance. Therefore, they could be used as potential therapeutic targets. This study aimed to evaluate pSTAT3 and CTLA4 expression levels and their possible roles as prognostic and predictive biomarkers in CRC using immunohistochemistry (IHC). Methods: This retrospective study included 113 CRC patients. Tissue microarrays were constructed, followed by pSTAT3 and CTLA4 antibodies immunostaining. Their expression was assessed and compared with the clinicopathological parameters and survival data. Results: Both pSTAT3 and CTLA4 overexpression were significantly associated with poor prognostic parameters, such as the presence of distant metastasis (P=0.02 & 0.03), high grade (P<0.001 & 0.03), high mitotic count (P<0.001 & 0.03), high tumor budding group (P=0.008 & 0.04), infiltrating tumor border (P<0.001 & 0.007) respectively, and advanced pathological stage with pSTAT3 (P=0.02). A significant association was found between overexpression of both markers and short overall survival. Correlations between the H-score of pSTAT3 and CTLA4 in CRC showed a significant positive correlation (P<0.001). Conclusion: STAT3 and CTLA4 positivity may be linked to the development and progression of the CRC, and they may provide potential prognostic indicators and therapeutic targets for CRC patients.