Levels Of sCTLA-4 Research Articles

Changes in the level of immune checkpoints in patients with various forms of autoimmune thyroiditis

Background. Autoimmune thyroiditis (AIT) affects more than 5 % of the world’s population.The aim. To determine the level of sPD-1, sPD-L1, sCTLA-4 and sB7.2 molecules in individuals suffering from various forms of autoimmune thyroiditis.Methods. The study included 31 individuals aged 18 to 40 years. They were divided into four groups: group I – healthy individuals (n = 10); group II – carriers of antibodies to thyroid peroxidase (n = 11); group III – individuals with AIT accompanied with subclinical form of hypothyroidism (n = 6); group IV – individuals with AIT complicated by compensated hypothyroidism (n = 4). Venous blood was collected to determine the level of antibodies to thyroid peroxidase using enzyme immunoassay, the concentration of thyroid stimulating hormone and free thyroxine – using chemiluminescence immunoassay, and the levels of sPD-1, sPD-1L, sCTLA-4, and sB7.2 – using flow cytofluorometry. Statistical processing was performed using the Kruskal – Wallis one-way analysis of variance.Results. When comparing the level of sPD-1L in groups I (54.1 (28.7; 67.6) pg/ml) and II (4.36 (2.36; 18.0) pg/ml), the decreased in this indicator was 91.94 % (p = 0.001). When comparing the sPD-1 level in the group of healthy individuals (16.6 (13.6; 37.2) pg/ml) and group IV (7.28 (5.18; 11.1) pg/ml), werecorded a decrease of 56.14 % (p = 0.001). The sB7.2 concentration decreased by 65.03 % in group II (16.4 (15.6; 32.7) pg/ml) compared to the control group (46.9 (39.3; 54.4) pg/ml) (p = 0.001). In group III, the sCTLA-4 level was 3.22 (3.06; 3.33) pg/ml and decreased by 88.66% compared to the control group (p = 0.001).Conclusion. The development of autoimmune thyroiditis is accompanied with the decrease in the concentration of sPD-1, sPD-1L, sCTLA-4 and sB7.2.

Soluble cytotoxic T-lymphocyte antigen-4 (sCTLA-4) in children with immune cytopenia: relation to disease activity

Cytotoxic T-lymphocyte associated antigen-4 (CTLA-4) is a costimulatory receptor exhibiting a potent inhibitory signal on antigen-activated immune responses. A soluble form, sCTLA-4, has been identified and was found to be increased in several autoimmune diseases. We aimed to evaluate serum levels of sCTLA-4 in different immune cytopenias, and to determine its possible relation to the disease activity. We measured serum levels of sCTLA-4 in 47 patients with immune cytopenias and compared them to 47 age- and sex-matched healthy controls. sCTLA-4 levels were significantly higher in patients with immune cytopenias compared to healthy controls (p < 0.001), however, levels were comparable between different groups of immune cytopenias (p = 0.084). Serum sCTLA-4 inversely correlated with age at diagnosis and hemoglobin level (p = 0.048, and p = 0.039 respectively), while it directly correlated with disease duration (p = 0.023) as well as markers of hemolysis including reticulocyte count, serum LDH and indirect bilirubin (p = 0.025; p = 0.019; p = 0.004 respectively). In the AIHA group, serum sCTLA-4 levels were significantly lower in patients in remission compared to patients with active disease (p = 0.026). Children with immune cytopenia exhibit significantly higher levels of circulating sCTLA-4 which correlated with disease activity, yet the prognostic significance and its use to tailor treatment regimen require additional studies.

Correlation between sCTLA-4 and sCD86 Levels with Disease Activity of Systemic Lupus Erythematosus (SLE) Patients Based on SLEDAI Score

Background. Systemic Lupus Erythematosus (SLE) is an autoimmune disease with multisystem involvement which arises from multifactorial causes. Continuous exposure to autoantigens and chronic activation of the immune system, especially memory T lymphocytes, contribute to premature immunosenescence. sCTLA-4 and sCD86 are soluble costimulatory molecules of CTLA-4 and CD86, which play a role in the occurrence of immunosenescence in SLE. The presence of immunosenescence will cause higher morbidity and mortality. This research was conducted to establish the correlation between the increased levels of sCTLA-4 and sCD86 and the severity of SLE, as measured by the SLE Disease Activity Index (SLEDAI) score. Methods. This analytical observational research utilized a cross-sectional approach involving 35 female SLE patients diagnosed according to the SLICC 2012 criteria. SLE disease activity was measured using SLEDAI score. Serum sCTLA-4 and sCD86 levels were measured using the ELISA method. Statistical analysis was conducted using the Mann-Whitney test for comparisons and the Spearman test for correlation analysis, with a significance level of p&lt;0.05. Results. sCTLA-4 levels were higher and significantly different in patients with moderate SLE (p=&lt;0.001; p&lt;0.05), and there was no significant difference in sCD86 levels (p=0.915; p&gt;0.05). Increased sCTLA-4 levels were positively correlated with the severity of SLE (r =0.361, p=0.033), while no significant correlation was observed in sCD86 levels (r=-0.094, p=0.591). Conclusion. Elevated sCTLA-4 levels were positively correlated with increased severity of SLE based on the SLEDAI score.

Polyarticular juvenile idiopathic arthritis has a distinct co-inhibitor receptor profile.

Juvenile Idiopathic Arthritis (JIA) is the most common rheumatic disease of childhood; the pathogenesis is associated with T cell activation. T cell activation can be counter-balanced by signals generated by inhibitory receptors (IRs) such as CTLA-4, PD-1, LAG-3, and TIM-3. Here, we identify the role of IRs in the pathogenesis of different JIA subtypes. In total, we included 67 oligoarticular JIA, 12 IgM-RF negative polyarticular JIA, 17 enthesitis related arthritis, 11 systemic JIA patients and 10 healthy controls. We collected plasma (and synovial fluid) samples from the patients either at the onset or during a flare of their disease. We measured the soluble levels of co-IRs (IL-2Rα, 4-1BB, CD86, TGF-β1, CTLA-4, PD-L1, PD-1, TIM-3, LAG- 3, Galectin-9) by cytometric bead array kits and their cellular expression (PD-1, CTLA-4, TIM-3, LAG-3) by flow cytometry. We compared the plasma levels and cellular expressions of different co-IRs within different JIA subgroups. The polyarticular-JIA group was different from the three other examined JIA subgroups, having higher levels of plasma sCTLA-4(p< 0.001), sPD-1(p< 0.05), and s4-1BB(p< 0.05) when compared with the other JIA subgroups and healthy controls. We analyzed the cellular surface expression of different co-IRs on the PBMCs of different JIA subtypes. Similar to plasma levels, both the percentage(p< 0.05) and the MFI (mean fluorescence intensity) (p< 0.01) of CTLA4 expression were higher in the poly-JIA subgroup. This is the first report studying the expression profile of different co-IRs in different subtypes of JIA. Polyarticular JIA patients had a different co-IR profile, having more CTLA-4, PD-1 and 4-1BB in their plasma than the other subtypes of JIA.

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

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. 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. 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. 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.

Abstract PO3-22-01: Characterization of peripheral T-cell dynamics in the patients with bone metastasis from breast cancer following stereotactic body radiotherapy

Abstract Purpose: Preclinical studies suggest that radiotherapy (RT) elicits various effects on antitumor T-cell responses. However, systemic T-cell responses upon RT in real-world cancer patients, including those with metastatic breast cancer, are poorly characterized. This study aims to investigate the detailed dynamics of peripheral T cells upon stereotactic body radiotherapy (SBRT) in metastatic breast cancer patients. Methods: Peripheral blood samples of 32 prospectively recruited patients who received SBRT to bone metastasis of breast cancer, which were acquired at pre-SBRT (W0), 1 week after SBRT (W1), and 4 weeks after SBRT (W4), were analyzed using multi-color flow cytometry and cytometric bead array. Most patients (n = 30) received SBRT of 1 fraction (n = 16) or 3 fractions (n = 14). We also performed a subgroup analysis of 22 patients who did not start a new systemic therapy within 1 month before SBRT (new systemic Tx &amp;gt;1mo) to exclude the effects of systemic therapies. Results: Peripheral PD-1+ CD8+ T cells, which are enriched for tumor-specific clonotypes, were activated with increased expression of Ki-67 at W1 compared to W0. Expression of Ki-67 on PD-1+ CD8+ T cells remained higher at W4 than W0, although it was not statistically significant. Moreover, expressions of Ki-67 and CTLA-4 on circulating regulatory T (TREG) cells were increased at W1 compared to W0. The suppressive (Foxp3hiCD45RA–) TREG cells also exhibited enhanced expressions of Ki-67 and CTLA-4 at W1. We defined immunologic responders (ImmRs) as patients with Ki-67 expression on PD-1+ CD8+ T cells at W1 greater than 1.5-times of W0, and otherwise immunologic non-responders (ImmNRs). Notably, fold changes in expressions of Ki-67 and CTLA-4 on TREG cells and proportion of suppressive TREG cells among total TREG cells at W1 over W0 were higher in ImmRs than ImmNRs. Similar phenotypical changes of T cells were observed in the subgroup analysis of the patients with new systemic Tx &amp;gt;1mo. The peripheral T-cell changes were not significantly different between the dose-fractionation schedules (1 fraction vs. 3 fractions) nor molecular subtypes of cancer. In patients with new systemic Tx &amp;gt;1mo, plasma level changes of TGF-β1, sCTLA-4, and s4-1BB at W1 compared to W0 were significantly higher in ImmRs compared to ImmNRs, while only change of s4-1BB was associated with the immunologic response. Conclusions: Our results suggest that circulating PD-1+ CD8+ T cells are activated upon SBRT. However, SBRT also results in the activation of circulating TREG cells, which was more prominent in patients with a significant activation of circulating PD-1+ CD8+ T cells. Alterations in plasma levels of TGF-β1, sCTLA-4, and s4-1BB are associated with the peripheral T-cell responses. Dose-fractionation schedule is not associated with the peripheral T-cell responses. Work supported by grants from the National Research Foundation of Korea (NRF-2023R1A2C3003782) Citation Format: Seung Hyuck Jeon, Eui-Cheol Shin, In Ah Kim. Characterization of peripheral T-cell dynamics in the patients with bone metastasis from breast cancer following stereotactic body radiotherapy [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-22-01.

Assessment of CTLA-4 Gene Expression Levels on CD8+ T Cells in Renal Transplant Patients and Relation with Serum sCTLA-4 Levels.

CTLA-4 (Cytotoxic T Lymphocyte Antigen-4) is an immune regulator molecule that is expressed on a variety of immune cells, including CD4+ and CD8+ T cells. After realizing the significance of this regulator molecule, researchers began to concentrate on its activation or inhibition in cancer. Even though there have been some studies on organ transplantation and autoimmunity, the role of the CTLA-4 molecule in renal transplantation has not been demonstrated. The goal of this study was to see how CTLA-4 gene expression and serum sCTLA-4 levels affected renal transplant patients. Peripheral blood samples were collected before and 1-3 months after renal transplantation from 29 recipients.CD8+ T lymphocytes were separated using magnetic beads and purity of the cells controlled by Flow cytometry. CTLA-4 mRNA levels were determined by Real-Time PCR while serum sCTLA-4 levels were assessed by ELISA. 55% of the patient had decreased level of CTLA-4 mRNA after transplantation when compared to pre-transplantation levels. Moreover 61% of the patient had lower serum sCTLA-4 levels after transplantation. sCTLA-4 levels were decreased 11% of the patients with rejection episode after transplantation when compared to stabile patients (5%). Kidney rejection is a complicated process influenced by numerous unknown factors. Several parameters should be evaluated together to precise rejection episodes or graft dysfunctions. Further research focused on the other immune checkpoint regulator molecules could give an opportunity to have an idea about the effect of these molecules on renal transplantation.

CRP and soluble CTLA4 are determinants of anti-PD1 resistance in gastrointestinal cancer.

Targeting immune inhibitory checkpoint (IC) pathways have attracted great attention as a promising strategy for treating gastrointestinal (GI) cancer. However, the therapeutic efficacy is low in most cases, and little progress has been made in establishing biomarkers that predict the possible responses, and combination regimens that enhance the therapeutic efficacy. As a predictive biomarker, soluble forms of IC molecules have been recently highlighted. However, little is known about which IC molecules is most critically associated with the treatment resistance, and also about the biological and immunological roles of the IC molecules in GI cancer. In this study, we analyzed sera obtained from advanced gastric cancer patients before and one month after treatment with anti-PD1 nivolumab for soluble IC molecules by ELISA. We found that decrease of soluble CTLA4 (sCTLA4) at posttreatment were significantly associated with a better prognosis, and combination with low level of CRP at posttreatment more clearly defined anti-PD1 responders with long-term survival. Indeed, in the in vitro setting, CRP stimulation upregulated CTLA4 expression in tumor cells followed by generation of sCTLA4 that suppressed CTL induction, and simultaneously conferred high self-renewal and invasive abilities on the tumor cells accompanied by increase of EMT-related gene expressions. In the in vivo setting, CRP injection elevated sCTLA4 level in sera of mouse tumor metastasis models, leading to failure of anti-PD1 therapy. However, treatment with anti-CTLA4 mAb or a PPARγ agonist that can reduce in vivo CRP successfully elicited anti-tumor efficacy in the anti-PD1 resistant models. These suggest that targeting CRP and sCTLA4 may be a promising strategy for improving clinical outcomes in the treatments, including anti-PD1 therapy, of GI cancer.

Characterization of Peripheral T-Cell Dynamics in the Patients with Bone Metastasis from Breast Cancer Following Stereotactic Body Radiotherapy

Preclinical studies suggest that radiotherapy (RT) elicits various effects on antitumor T-cell responses. However, systemic T-cell responses upon RT in real-world cancer patients, including those with metastatic breast cancer, are poorly characterized. This study aims to investigate the detailed dynamics of peripheral T cells upon stereotactic body radiotherapy (SBRT) in metastatic breast cancer patients. Peripheral blood samples of 32 prospectively recruited patients who received SBRT to bone metastasis of breast cancer, which were acquired at pre-SBRT (W0), 1 week after SBRT (W1), and 4 weeks after SBRT (W4), were analyzed using multi-color flow cytometry and cytometric bead array. Most patients (n = 30) received SBRT of 1 fraction (n = 16) or 3 fractions (n = 14). We also performed a subgroup analysis of 22 patients who did not start a new systemic therapy within 1 month before SBRT (new systemic Tx >1mo) to exclude the effects of systemic therapies. Peripheral PD-1+ CD8+ T cells, which are enriched for tumor-specific clonotypes, were activated with increased expression of Ki-67 at W1 compared to W0. Expression of Ki-67 on PD-1+ CD8+ T cells remained higher at W4 than W0, although it was not statistically significant. Moreover, expressions of Ki-67 and CTLA-4 on circulating regulatory T (TREG) cells were increased at W1 compared to W0. The suppressive (Foxp3hiCD45RA-) TREG cells also exhibited enhanced expressions of Ki-67 and CTLA-4 at W1. We defined immunologic responders (ImmRs) as patients with Ki-67 expression on PD-1+ CD8+ T cells at W1 greater than 1.5-times of W0, and otherwise immunologic non-responders (ImmNRs). Notably, fold changes in expressions of Ki-67 and CTLA-4 on TREG cells and proportion of suppressive TREG cells among total TREG cells at W1 over W0 were higher in ImmRs than ImmNRs. Similar phenotypical changes of T cells were observed in the subgroup analysis of the patients with new systemic Tx >1mo. The peripheral T-cell changes were not significantly different between the dose-fractionation schedules (1 fraction vs. 3 fractions) nor molecular subtypes of cancer. In patients with new systemic Tx >1mo, plasma level changes of TGF-β1, sCTLA-4, and s4-1BB at W1 compared to W0 were significantly higher in ImmRs compared to ImmNRs, while only change of s4-1BB was associated with the immunologic response. Our results suggest that circulating PD-1+ CD8+ T cells are activated upon SBRT. However, SBRT also results in the activation of circulating TREG cells, which was more prominent in patients with a significant activation of circulating PD-1+ CD8+ T cells. Alterations in plasma levels of TGF-β1, sCTLA-4, and s4-1BB are associated with the peripheral T-cell responses. Dose-fractionation schedule is not associated with the peripheral T-cell responses.

Quantitative analysis of soluble costimulatory molecules as potential diagnostic biomarkers for rheumatoid arthritis using LC-MS/MS in MRM mode

Background and aimsRheumatoid arthritis (RA) is a chronic autoimmune disease. RA-induced immunological responses are coordinated by T-cell stimulation. The costimulatory signal CD28-B7 is essential for T-cell activation by interacting CD28 with CD80 and CD86 costimulatory proteins. CTLA4 is another costimulatory protein that binds to CD80 and CD86 to inhibit T-cell activity. The soluble costimulatory proteins: sCD80, sCD86, sCD28, and sCTLA-4 were detected and quantified in human plasma and correlated with RA development. As potential diagnostic biomarkers for RA, developing a sensitive, specific, and reproducible method for quantifying these costimulatory molecules in human plasma and establishing quantitative ranges for each protein in healthy and RA patients' plasma is essential for advancing the clinical diagnostic and health outcomes. Materials and methodsA novel quantitative liquid chromatography-tandem spectrometry (LC-MS/MS) technique using multiple reaction monitoring (MRM) modes was developed and validated to measure soluble costimulatory molecules sCTLA4, sCD28, sCD80, and sCD86 in human plasma samples. Furthermore, the method was applied to determine sCTLA4, sCD28, sCD80, and sCD86 levels in plasma samples from RA patients (n = 23) and healthy controls (n = 21). ResultsThe method was successfully developed and validated according to international inter- and intra-assay precision and accuracy guidelines. The linearity of the method was achieved between 0.5 nM and 100 nM for each protein with a correlation coefficient of > 0.998. The plasma level of sCTLA4, sCD80, and sCD86 in RA patients was significantly elevated compared to controls. RA patients had 63.32 ± 17.63 nM sCTLA4 and controls 36.05 ± 18.83 nM; p < 0.0001. The performance of the four proteins was determined using ROC curves, where sCTLA4 showed the highest diagnostic and clinical performance compared to the others. ConclusionsThis study reports the first use of LC-MS/MS in MRM mode to accurately quantify soluble costimulatory molecules in plasma samples as potential RA diagnostic biomarkers. Determination of the reference range for each protein with high selectivity and sensitivity increases the potential for utilizing this method as a clinical diagnostic.

The Role of Soluble Costimulatory Molecules as the Biomarkers for Aging Predictors

This study aimed to determine the role of the soluble costimulatory molecules in aging and the association with the presence of comorbid in aged individuals. Thirty-two elderly and twenty healthy subjects were included in this study. The soluble costimulatory molecules sCD28, sCD80, sCD86, sCD163, and sCTLA4 were measured using ELISA. The presence of comorbid was documented from medical records. Charlson Comorbidity Index (CCI) was measured to evaluate the survival/mortality risk for the subjects. The levels of the majority of soluble costimulatory molecules significantly increased in the elderly participants, while the level of sCD86 was comparable. There were weak positive correlations between the subject's age and levels of sCD28 (R=0.214, p=0.048), sCTLA4 (R=0.238, p=0.041), and sCD80 (R=0.317, p=0.012). sCD80 were discovered to be the best to predict immune aging in the elderly with AUC 0.71 [0.57-0.86], sensitivity 53,1%, specificity 80.0%, and cut off 129ng/ml. Most of the elderly participants had at least one comorbid, in which approximately 25.0% and 3.1% of the subjects were classified as mild and moderate CCI. Multivariate analysis showed that comorbidities in elderly individuals have been associated with levels of sCTLA4 ≥26.5ng/ml and sCD80 ≥129.0ng/ml. Furthermore, subjects with comorbid (CCI ≥1) were associated with sCD80 ≥129.0ng/ml (OR 12.44 [95% CI 1.32–117.03], p=0.027). Considering these results, sCD28, sCTLA4, and sCD80 can be developed as biomarkers for predicting immune aging and elderly comorbidities, respectively.

Mapping the immune landscape in small cell lung cancer by analysing expression of immuno-modulators in tissue biopsies and paired blood samples

Small cell lung carcinomas (SCLC) are aggressive tumors with high propensity to metastasize. Recent NCCN guidelines have incorporated immunotherapy in extensive stage SCLC. Limited benefit in few patients compounded by side effects of unwonted immune-checkpoint-inhibitor (ICPI) usage necessitates identification of potential biomarkers predicting response to ICPIs. Attempting this, we analysed expression of various immunoregulatory molecules in tissue biopsies and paired blood samples of SCLC patients. In 40 cases, immunohistochemistry for expression of immune inhibitory receptors CTLA-4, PD-L1 and IDO1 was performed. Matched blood samples were quantified for IFN-γ, IL-2, TNF-α and sCTLA-4 levels using immunoassay and additionally for IDO1 activity (Kynurenine/Tryptophan ratio) using LC–MS. Immunopositivity for PD-L1, IDO1 and CTLA-4 was identified in 9.3%, 6.2% and 71.8% cases, respectively. Concentration of serum IFN-γ (p-value < 0.001), TNF-α (p-value = 0.025) and s-CTLA4 (p-value = 0.08) were higher in SCLC patients while IL-2 was lower (p-value = 0.003) as compared to healthy controls. IDO1 activity was significantly elevated in SCLC cohort (p-value = 0.007). We proffer that SCLC patients show immune suppressive milieu in their peripheral circulation. Analysis of CTLA4 immunohistochemical expression along with s-CTLA4 levels appears prospective as biomarkers for predicting responsiveness to ICPIs. Additionally, evaluation of IDO1 appears cogent both as prognostic marker and potential therapeutic target as well.

Soluble programmed cell death ligand 1 predicts prognosis for gastric cancer patients treated with nivolumab: Blood-based biomarker analysis for the DELIVER trial

BackgroundThe clinical value of soluble forms of programmed cell death–1 (sPD-1), PD ligand 1 (sPD-L1) and cytotoxic T lymphocyte–associated protein–4 (sCTLA-4) for gastric cancer (GC) patients treated with nivolumab monotherapy has remained unknown. MethodsBlood samples collected before nivolumab treatment from 439 GC patients enrolled in the DELIVER (Japan Clinical Cancer Research Organisation GC-08) trial were analysed for sPD-1, sPD-L1 and sCTLA-4. Corresponding baseline clinical data were also retrieved. ResultsHigher plasma levels of sPD-1 (hazard ratio [HR] = 1.27, p = 0.020), sPD-L1 (HR = 1.86, p < 0.001) and sCTLA-4 (HR = 1.33, p = 0.008) were significantly associated with shorter overall survival (OS), whereas only higher sPD-L1 levels was significantly associated with shorter progression-free survival (HR = 1.30, p = 0.008). The sPD-L1 concentration was significantly associated with the Glasgow prognostic score (GPS) (p < 0.001), but both sPD-L1 (HR = 1.67, p < 0.001) and GPS (HR = 1.39, p = 0.009 for GPS 0 versus 1; HR = 1.95, p < 0.001 for GPS 0 versus 2) were independently associated with OS. Patients with a GPS of 0 and low sPD-L1 thus showed the longest OS (median, 12.0 months) and those with a GPS of 2 and high sPD-L1 showed the shortest OS (median, 3.1 months), yielding a HR of 3.69 (p < 0.001). ConclusionBaseline sPD-L1 levels have the potential to predict survival for advanced GC patients treated with nivolumab, with the prognostic accuracy of sPD-L1 being improved by its combination with GPS.

Role of soluble forms of follicular helper T-cell membrane molecules in the pathogenesis of myasthenia gravis

This study examined the role of Tfh and Treg associated molecules also known as checkpoint molecules, their ligands, and IL-21 in myasthenia gravis (MG) pathogenesis. Serum levels of sPD-1, sPD-L1, sICOS, sICOSLG, sCTLA4, and IL-21 were measured in 39 patients with acetylcholine receptor (AChR) antibody-positive generalized MG and 27 controls. sPD-1 and IL-21 levels were higher in MG patients than in controls. Additionally, sPD-1 levels correlated positively with the levels of IL-21, sICOSLG, sCTLA4, and AChR antibody titers. sICOS are correlated with MGADL and AChR antibody titers. These Tfh associated molecules could be used as biomarkers of MG disease activity.

Soluble immune checkpoint molecules in patients with antineutrophil cytoplasmic antibody-associated vasculitis

Immune checkpoint molecules balance immune effector responses with regulatory reactions. We speculated that soluble immune checkpoint molecules are involved in dysregulation of the immune response and autoimmunity. We evaluated the association between soluble immune checkpoint molecules and antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV).A total of 56 patients with AAV from a prospective observational cohort and 40 healthy controls (HCs) were analyzed. Soluble PD-1, PD-L1, PD-L2, CTLA-4, CD28, CD80, CD86, ICOS, TIM-3, BTLA, CD40, LAG-3, TLR-2, and CD27 were measured in stored sera using the Milliplex MAP assay. Paired analyses were performed before and after the treatment. AAV-specific indices, including Birmingham vasculitis activity score, five factor score , vasculitis damage index, and blood samples, were collected.Patients with AAV had higher levels of sPD-L1, sCD28, sCD80, sCD86, sICOS, sTIM-3, sLAG-3, sTLR-2, and sCD27 and lower level of sCTLA-4 than HCs (p < 0.05). Patients with AAV had higher serum sCD28, sCD80, sTIM-3, and sCD27 levels than HCs at baseline and decreased after treatment. Furthermore, the serum levels of sCD28 and sTIM-3 were significantly correlated with disease activity.This study demonstrated altered concentrations of serum soluble immune checkpoint molecules in patients with AAV. In particular, sCD28 and sTIM-3 may act as surrogate markers of AAV disease activity.

Downregulation of sCD40 and sCTLA4 in Recovered COVID-19 Patients with Comorbidities.

The aim of this study was to analyze molecules associated with regulatory immune response in unvaccinated, recovered COVID-19 patients with and without diabetes mellitus (DM) and hypertension (HTN). We determined anti-SARS-CoV-2 nucleocapsid IgG in plasma by electrochemiluminescence immunoassay. The levels of sCD40, TGF-ß, IL-10, and sCTLA-4 were assessed by ELISA in the serum of the subjects, as well as in healthy donors. We observed that only half of the subjects in the non-comorbid group produced antibodies, whereas all subjects in comorbid groups were IgG-positive for the anti-SARS-CoV-2 nucleocapsid. High levels of sCTL-4 were observed in the non-comorbid group, and the level of IL-10 was observed to increase in seropositive subjects without comorbidities. TGF-ß concentration was similar in all groups studied. Finally, sCD40 decreased in the comorbid group. In conclusion, our results suggest that comorbidities such as DM and HTN alter the production of co-stimulatory inhibitory molecules sCTLA-4 and sCD40 in subjects recovering from mild COVID-19. The alterations observed here were independent of seropositivity, suggesting an effective humoral immune response against COVID-19 separate from the levels of co-stimulatory inhibitory molecules.

Characterization of multiple soluble immune checkpoints in individuals with different Mycobacterium tuberculosis infection status and dynamic changes during anti-tuberculosis treatment

BackgroundImmune checkpoints are crucial for the maintenance of subtle balance between self-tolerance and effector immune responses, but the role of soluble immune checkpoints (sICs) in Mycobacterium tuberculosis (M. tb) infection remains unknown. We assessed the levels of multiple sICs in individuals with distinct M. tb infection status, and their dynamic changes during anti-tuberculosis treatment.MethodsWe enrolled 24 patients with pulmonary tuberculosis, among which 10 patients were diagnosed with tuberculous pleurisy (TBP), 10 individuals with latent tuberculosis infection (LTBI), and 10 healthy volunteers from Wuxi Fifth People’s Hospital and Huashan Hospital between February 2019 and May 2021. Plasma concentrations of thirteen sICs were measured at enrollment and during anti-tuberculosis treatment using luminex-based multiplex assay. sICs levels in tuberculous pleural effusion (TPE) and their relations to laboratory test markers of TPE were also assessed in TBP patients.ResultsThe circulating levels of sPD-1, sPD-L1, sCTLA-4, sBTLA, sGITR, sIDO, sCD28, sCD27 and s4-1BB were upregulated in tuberculosis patients than in healthy controls. A lower sPD-L1 level was found in LTBI individuals than in tuberculosis patients. In TBP patients, the levels of sPD-1, sPD-L2, sCD28, sCD80, sCD27, sTIM-3, sLAG-3, sBTLA, s4-1BB and sIDO increased significantly in TPE than in plasma. In TPE, sBTLA and sLAG-3 correlated positively with the adenosine deaminase level. sIDO and sCD80 correlated positively with the lactate dehydrogenase level and the percentage of lymphocytes in TPE, respectively. Meanwhile, sCD27 correlated negatively with the specific gravity and protein level in TPE. In tuberculosis patients, the circulating levels of sBTLA and sPD-L1 gradually declined during anti-tuberculosis treatment.ConclusionsWe characterized the changing balance of sICs in M. tb infection. And our results revealed the relations of sICs to laboratory test markers and treatment responses in tuberculosis patients, indicating that certain sICs may serve as potential biomarkers for disease surveillance and prognosis of tuberculosis.

Concurrent Chemoradiotherapy Increases the Levels of Soluble Immune Checkpoint Proteins in Patients with Locally Advanced Cervical Cancer.

Purpose Concurrent chemoradiotherapy (CCRT) has been widely applied to locally advanced cervical cancer (LACC) patients, inducing the massive release of antigen and systematic immunomodulatory effects. However, its effect on the soluble immune checkpoint proteins (sICPs) remains unclear, which might play a key role in the immune response. Therefore, the current study explored changes in the levels of 16 sICPs in LACC patients during CCRT. Methods We prospectively enrolled fifty-one LACC patients treated with CCRT and collected patients' blood before, during and after CCRT. The levels of 16 sICPs were measured using the Luminex platform, and the changes were measured using Friedman test with Bonferroni's posttest. One month after CCRT, the tumor response was evaluated according to the RECIST 1.1 guidelines. Results The levels of soluble T-cell immunoglobulin and mucin-domain containing-3 (sTIM-3) significantly increased during CCRT (P = 0.041), while those of the soluble B and T lymphocyte attenuator (sBTLA), sCD40, soluble glucocorticoid-induced tumor necrosis factor receptor ligand (sGITRL), sCD80, sCD86, sPD-1, sPD-L1, sCTLA-4, and soluble inducible T-cell costimulator (sICOS) significantly increased after CCRT (all P < 0.05). Other sICPs showed no significant changes throughout the CCRT (all P > 0.05). 41 (80%), 8 (16%), and 2 (4%) patients showed complete response (CR), partial response (PR), and stable disease (SD) after CCRT, respectively. Interestingly, the level of soluble lymphocyte-activation gene 3 (sLAG-3) was significantly higher among the PR/SD patients as compared to the CR after CCRT (P = 0.009). Conclusions This study revealed that CCRT might elevate the serum levels of sTIM-3, sBTLA, sCD40, sGITRL, sCD80, sCD86, sPD-1, sPD-L1, sCTLA-4, and sICOS in the patients with LACC. The sLAG-3 level was higher in the patients with poor response to CCRT. These findings revealed the dynamic changes in the sICPs levels during CCRT, which might be helpful in designing optimal treatment strategies for LACC patients.

TGFβ2 Induces the Soluble Isoform of CTLA-4 - Implications for CTLA-4 Based Checkpoint Inhibitor Antibodies in Malignant Melanoma.

Malignant melanoma is an aggressive form of cancer, which can be treated with anti-CTLA-4 and anti-PD-1 checkpoint inhibitor antibodies but while anti-CTLA-4 antibodies have clear benefits for some patients with melanoma, productive responses are difficult to predict and often associated with serious immune related adverse events. Antibodies specific to CTLA-4 bind two major isoforms of CTLA-4 in humans, the receptor isoform and a second naturally secretable, soluble isoform - sCTLA-4. The primary aim here was to examine the effect of selectively blocking the function of sCTLA-4 on in vitro immune responses from volunteer healthy or melanoma patient PBMC samples. Addition of recombinant sCTLA-4 to healthy PBMC samples demonstrated sCTLA-4 to have immunosuppressive capacity comparable to recombinant CTLA4-Ig, partially reversible upon antibody blockade. Further, we identified a mechanistic relationship where melanoma patient TGFβ2 serum levels correlated with sCTLA-4 levels and provided the basis for a novel protocol to enhance sCTLA-4 production and secretion by T cells with TGFβ2. Finally, a comparison of selective antibody blockade of sCTLA-4 demonstrated that both healthy and melanoma patient effector cytokine responses can be significantly increased. Overall, the data support the notion that sCTLA-4 is a contributory factor in cancer immune evasion.

Serum Soluble Cytotoxic T-Lymphocyte-Associated Antigen 4 in Children and Adolescents with Autoimmune Cytopenia

Abstract Background Autoimmune cytopenias are characterized by the production of autoantibodies against differentiated hematopoietic cells because of defects in central and/or peripheral tolerance. It includes autoimmune hemolytic anemia (AIHA), immune thrombocytopenic purpura (ITP), autoimmune proliferative syndrome (ALPS) and Evans syndrome (EV). Aim of the Work to compare levels of sCTLA-4 in different types of immune cytopenias and their control. Patients and Methods Forty seven children and adolescents who have autoimmune cytopenias were recruited and assessed for eligibility in Pediatric Hematology Clinic, Ain Shams University Children’s Hospital and forming a patients group with age range 8 – 204 months old. An age and sex matched healthy control group were recruited including forty seven healthy participants with age range 6 – 156 months old. Results On initial examination in our study, the prevalence of hepatosplenomegaly and lymphadenopathy among the patients group was 27.7% and 2.1% respectively. Autoimmune cytopenic patients group have statistically significant higher serum sCTLA-4 levels (range 1 – 82 ng/ml) than control group (range 0 – 9 ng/ml) (where P &amp;lt; 0.01 HS). On the other hand, there was no significant difference when comparing levels of sCTLA-4 between sera of ITP, AIHA and ALPS patients (P &amp;gt; 0.05). Serum sCTLA-4 was inversely related to the age at diagnosis and positively related to disease duration. Our results demonstrated the presence of correlations between the levels of sCTLA4 and the severity of autoimmune cytopenias (negative correlation with Hemoglobin (R= -0.315; P = 0.031), mean Hemoglobin (last year) (R= -0.471; P = 0.001) and platelet (R= -0.324; P &amp;lt; 0.05)) and (positive correlation between levels of sCTLA-4 and Reticulocyte count (R = 0.413; P = 0.004), Indirect Bilirubin (R = 0.427; P = 0.003) and Lactate dehydrogenase (R = 0.357; P = 0.014)). There was a significant differences in the prevalence of hepatosplenomegaly among ITP, AIHA and ALPS patients (P &amp;lt; 0.05) with higher prevalence among ALPS patients. Conclusion Soluble form of CTLA4 (sCTLA4) presents in elevated levels in the sera of children and adolescents who have autoimmune cytopenia including AIHA/Evans, ITP and ALPS compared to healthy control group that suggests sCTLA4 could play a role in the pathogenesis of immune cytopenias.