T-cell Numbers Research Articles

Peritoneal Dialysis Aggravates and Accelerates Atherosclerosis in Uremic ApoE-/- Mice.

Atherosclerosis is highly prevalent in people with chronic kidney disease (CKD), including those receiving peritoneal dialysis (PD). Although it is lifesaving, PD induces profound systemic inflammation, which may aggravate atherosclerosis. Therefore, the hypothesis is that this PD-induced inflammation aggravates atherosclerosis via immune cell activation. ApoE-/- mice were subjected to a 5/6 nephrectomy to induce CKD. Three weeks later, mice were fed a high-cholesterol diet. Half of the nephrectomized mice then received daily peritoneal infusions of 3.86% Physioneal for 67 further days (CKD+PD) until the end of the experiment, and were compared with mice without CKD. Sham operated and PD-only mice were additional controls. CKD+PD mice displayed more severe atherosclerotic disease than control mice. Plaque area increased, and plaques were more advanced with a vulnerable phenotype typified by decreased collagen content and decreased fibrous cap thickness. Increased CD3+ T-cell numbers were present in plaques and perivascular adipose tissue of CKD and CKD+PD mice. Plaques of CKD+PD mice contained more iNOS+ immune cells. Spleens of CKD+PD mice showed more CD4+ central memory, terminally differentiated type 1 T-helper (Th1), Th17, and CX3C motif chemokine receptor 1+ (CX3CR1) CD4+ T-cells with less regulatory and effector T-cells. PD-fluid exposure in uremic mice potentiates systemic and vascular T-cell-driven inflammation and aggravates atherosclerosis. PD polarized CD4+ T-cells toward an inflammatory Th1/Th17 phenotype, and increased CX3CR1+ CD4+ T-cells, which are associated with vascular homing in CKD-associated atherosclerosis. Targeting CD4+ T-cell activation and CX3CR1+ polarization has the potential to attenuate atherosclerosis in PD patients.

Similar Viral and Immune Characteristics of Kaposi Sarcoma in ART-treated People Living With HIV and Older Patients With Classic Kaposi Sarcoma.

Reemergence of human herpesvirus 8 (HHV-8)-induced Kaposi sarcoma (KS) in people living with HIV (PLWH) despite antiretroviral therapy (ART) poses a clinical challenge because they already have favorable CD4 T-cell numbers and undetectable viral loads. We observed that clinical presentation in PLWH on ART resembled classic KS found in older HIV-uninfected patients and hypothesized that immunosenescence may thus play a role in occurrence of KS on ART. We compared viral and immune factors implicated in the development of KS in ART-treated PLWH (HIV KS) and HIV-uninfected classic KS patients (cKS), compared to controls without KS (HIV Control, cControls respectively). Plasma, peripheral blood mononuclear cell, and skin tissues were obtained from 11 HIV KS and 11 cKS patients and 2 groups of age-matched controls. HIV KS participants were younger than cKS (aged 53 vs 75 years). HHV-8 genotypes did not differ between groups. Despite the younger age and a lower CD4/CD8 ratio, activated, exhausted, and senescent T-cell frequencies were similar between HIV KS and cKS. Anti-HHV-8 immunoglobulin G levels were higher and circulating HHV-8 DNA lower in HIV KS compared with cKS. Circulating platelet-derived growth factors AA-BB and granulocyte colony-stimulating factors were higher in HIV KS We observed similar levels of HHV-8 DNA and PD-1 expression in skin lesions from HIV KS and cKS patients. Altogether, early immune senescence could be involved in the development of KS in ART-treated PLWH. Higher anti-HHV-8 immunoglobulin G levels could be linked with lower circulating viral load. Such insights should help developing therapeutical strategies to prevent development and treat KS in PLWH on ART.

Live Rotavirus Vaccination Appears Low-risk in Infants Born to Mothers With Inflammatory Bowel Disease on Biologics

Biologic therapies in the context of inflammatory bowel disease and pregnancy lead to improved maternal and fetal outcomes. Placental transfer results in detectable drug concentrations in infants. Rotavirus infection results in diarrheal related hospitalizations; however, the live oral vaccine is not currently recommended in biologic exposed infants. The aim of this study was to assess the effect of maternal biologic therapies on the infant immune system and safety of live rotavirus vaccination in biologic-exposed infants. Biologic-exposed infants underwent standardized clinical assessments, drug concentration, and immune function testing (complete blood count, differential, immunoglobulin levels, extended B-cell and T-cell subset enumeration, Recent Thymic Emigrants, regulatory T-cell numbers, mitogen stimulation assays, and review of T-cell Receptor Excision Circles in the newborn screen). Rotavirus vaccine-specific adverse effects following immunizations up to 42 days post the last dose of the vaccine series were recorded. There were 57 infants born to 52 mothers with inflammatory bowel disease exposed to infliximab (n= 21), adalimumab (n= 19), vedolizumab (n= 10), and ustekinumab (n= 7) in the third trimester for a median of 39 weeks (interquartile range, 38-39 weeks) at delivery. Immunologic assessments validated for age were normal in all infants despite median infliximab concentrations of 6.1 ug/mL (range, 0.4-28.8 ug/mL), adalimumab concentrations of 1.7ug/mL (range, 0.7-7.9 ug/mL), ustekinumab concentrations of 0.6 ug/mL (range, 0-1.1), and undetectable for vedolizumab at 10.7 weeks (interquartile range, 9.4-12.4) of age. The live oral rotavirus vaccine series was provided to 50 infants with the first dose given at a median of 13weeks of age. No adverse effects following immunization were reported. Immune function testing was normal, and administration of live rotavirus vaccination appeared low-risk in biologic-exposed infants irrespective of circulating drug levels.

Cytomegalovirus infection is associated with thymic dysfunction and chronic graft-versus-host disease after pediatric hematopoietic stem cell transplantation

Pediatric hematopoietic stem cell transplantation (HSCT) is challenged by chronic graft-versus-host disease (cGvHD) significantly affecting survival and long-term morbidity, but underlying mechanisms including the impact of post-HSCT CMV infection are sparsely studied.We first investigated the impact of CMV infection for development of cGvHD in 322 children undergoing standard myeloablative HSCT between 2000 and 2018. Clinically significant CMV infection (n = 61) was an independent risk factor for chronic GvHD in a multivariable Cox regression analysis (HR = 2.17, 95% CI = 1.18–3.97, P = 0.013). We next explored the underlying mechanisms in a subcohort of 39 children. CMV infection was followed by reduced concentration of recent thymic emigrants (17.5 vs. 51.9 × 106/L, P = 0.048) and naïve CD4+ and CD8+ T cells at 6 months post-HSCT (all P < 0.05). Furthermore, CD25highFOXP3+ Tregs tended to be lower in patients with CMV infection (2.9 vs. 9.6 × 106/L, P = 0.055), including Tregs expressing the naivety markers CD45RA and Helios. CD8+ T-cell numbers rose after CMV infection and was dominated by exhausted PD1-expressing cells (66% vs. 39%, P = 0.023).These findings indicate that post-HSCT CMV infection is a main risk factor for development of chronic GvHD after pediatric HSCT and suggest that this effect is caused by reduced thymic function with a persistently impaired production of naïve and regulatory T cells in combination with increased peripheral T-cell exhaustion.

DIPG-13. TIM-3 TARGETED APTAMER IN COMBINATION WITH LOCO-REGIONAL RADIOTHERAPY IMPROVES SURVIVAL BY MODULATING THE IMMUNE INFILTRATION IN DIFFUSE MIDLINE GLIOMA MODELS

Abstract BACKGROUND Diffuse midline gliomas (DMG) are the most aggressive pediatric brain tumors. Their meager survival has not changed in the last decades emphasizing the urgent need for effective treatments. TIM-3 has emerged as a new target expressed in multiple immune cell types, regulating adaptive and innate immunity. In this work, we used an aptamer against TIM-3 to modify the tumor microenvironment and enhance the antitumor effect. METHODS For in vivo experiments, DMG murine cells were injected orthotopically into the pons of mice using a screw-guided system. The aptamer was administered intracranially (380pmol) on day 5 with the same system and three times intravenous (320pmol/mouse) 8-11-14 days after tumor implantation. In the radiotherapy experiments, 6Gy was given on day 7. Tumor and immune populations were analyzed by flow cytometry. RESULTS TIM-3 aptamer as monotherapy increases immune infiltration and elicits a specific immune response with a modest tendency to improve overall survival. Interestingly, we observed that radiotherapy, DMG standard of care, significantly induced TIM-3 expression in tumor and immune cells in the tumor microenvironment (TME). The combination of TIM-3 aptamer with radiotherapy increased the overall survival (3-fold), led to long-term survivors (30-50%), and generated immune memory in three different glioma models. Importantly, combination treatment significantly increases the infiltration of immune cells (3-fold) in the TME compared with the control groups. Radiotherapy and TIM-3 Apt treatment significantly increased the number and proliferative state of microglia, dendritic, NK, CD4, and CD8 T-cells. Interestingly, TIM-3 aptamer decreased the number and proliferative state of Tregs increasing the pro-inflammatory ratio of CD8: Tregs in the TME compared to non-treated groups after radiotherapy. CONCLUSIONS In conclusion, we provide evidence that combining radiotherapy with a TIM-3 aptamer increases overall survival, leads to the expansion of myeloid and T-cells in the TME, and generates immune memory in DMG models.

IL-15/IL-15Rα-Fc-Fusion Protein XmAb24306 Potentiates Activity of CD3 Bispecific Antibodies through Enhancing T-Cell Expansion.

An insufficient quantity of functional T cells is a likely factor limiting the clinical activity of T-cell bispecific antibodies, especially in solid tumor indications. We hypothesized that XmAb24306 (efbalropendekin alfa), a lymphoproliferative interleukin (IL)-15/IL-15 receptor α (IL-15Rα) Fc-fusion protein, may potentiate the activity of T-cell dependent (TDB) antibodies. The activation of human peripheral T cells by cevostamab, an anti-FcRH5/CD3 TDB, or anti-HER2/CD3 TDB resulted in the upregulation of the IL-2/15Rβ (CD122) receptor subunit in nearly all CD8+ and majority of CD4+ T cells, suggesting that TDB treatment may sensitize T cells to IL-15. XmAb24306 enhanced T-cell bispecific antibody-induced CD8+ and CD4+ T-cell proliferation and expansion. In vitro combination of XmAb24306 with cevostamab or anti-HER2/CD3 TDB resulted in significant enhancement of tumor cell killing, which was reversed when T-cell numbers were normalized, suggesting that T-cell expansion is the main mechanism of the observed benefit. Pretreatment of immunocompetent mice with a mouse-reactive surrogate of XmAb24306 (mIL-15-Fc) resulted in a significant increase of T cells in the blood, spleen, and tumors and converted transient anti-HER2/CD3 TDB responses to complete durable responses. In summary, our results support the hypothesis that the number of tumor-infiltrating T cells is rate limiting for the activity of solid tumor-targeting TDBs. Upregulation of CD122 by TDB treatment and the observed synergy with XmAb24306 and T-cell bispecific antibodies support clinical evaluation of this novel immunotherapy combination.

ИЗУЧЕНИЕ КЛИНИКО-ГЕМАТОЛОГИЧЕСКИХ И ИММУНОЛОГИЧЕСКИХ ПОКАЗАТЕЛЕЙ ПРИ ОЦЕНКЕ ПРОТИВОРАДИАЦИОННОЙ ЭФФЕКТИВНОСТИ ТЕРАПЕВТИЧЕСКОГО СРЕДСТВА НА ОСНОВЕ МИКРООРГАНИЗМА FUSOBACTERIUM NECROPHORUM

Purpose: To study clinical, hematologic and immunologic parameters in assessing the anti-radiation efficacy of the therapeutic agent based on the microorganism Fusobacterium necrophorum. Material and methods: The studies on determination of the anti-radiation efficacy of the strains of microorganisms killed by gamma-irradiation were carried out on sexually mature sexless white mice and white rats with live weight of 18–20 and 180–200 g, respectively, divided into experimental and control groups according to the principle of analogs. Modeling of acute radiation sickness was carried out on a Puma gamma unit with a radioactive source of cesium-137 at a dose of LD100/30. As potential anti-radiation drugs we used inactivated by irradiation on the gamma unit Explorer preparations of microbial origin F. necrophorum strain 8. necrophorum strain 8TS630501 at doses of 15, 20, 25 and 30 kGy. The tested preparations were injected subcutaneously in the volume of 0.2 cm3 to white mice and 2.0 cm3 to white rats 3 days after radiation exposure. Results: It was experimentally established that complete sterilization of the microbe occurs at doses of 25 and 30 kGy. The culture of F. necrophorum, irradiated at doses of 25 and 30 kGy and administered to animals 3 days after external radiation exposure, promoted survival, preservation of 60 to 80 % of lethally irradiated white mice and rats. At the same time the recovery of leukocytes and hemoglobin number was slow and continued until the end of the study. In animals treated with the developed therapeutic agents, there was also a decrease in the number of T-cells, but it was less pronounced than in the irradiation control group. The number of B-lymphocytes was affected similarly to T-lymphocytes. The minimum of the number of B-lymphocytes in the experimental groups was noted at 14 days. Studies on the intensity of the process of lipid peroxidation (LPO) in the content of malonic dialdehyde in peripheral blood of gamma-irradiated, treated and intact rats, it was found that in the irradiated control group there is a significant increase in the LPO index in blood in relation to biological control and treatment groups. Conclusion: It has been established that the highest anti-radiation efficacy is possessed by a therapeutic agent of microbial origin (RNF-30), which was obtained by gamma-irradiation at a dose of 30 kGy of the culture of F. necrophorum.

#2238 In kidney transplant recipients, response to vaccination with Tozimameran is associated with T-cell activation, but not senescence or exhaustion

Abstract Background and Aims Responses to vaccinations among kidney transplant recipients (KTRs) tend to be impaired compared to those of healthy individuals, a fact that can, to some degree, be attributed to their more senescent immune system profile. However, in the current literature, few data regarding the potential effects of multiple vaccinations on these patients’ immune system aging process are available. The aim of our research was to examine whether response to anti-SARS-CoV-2 vaccination with Tozinameran is associated with immunosenescence and immunoexhaustion in KTRs, focusing on CD4+ and CD8+ T-cell subsets. We additionally attempted to define parameters implicated in CD4+ and CD8+ differentiation process. Method We performed a prospective, observational study. Our sample consisted of 39 adult KTRs on stable immunosuppression, naïve to SARS-CoV-2. We evaluated them at two time points: T1 (48 hours prior to the 3rd Tozinameran dose) and T2 (3 weeks after the 3rd Tozinameran dose), by measuring: a) anti-SARS-CoV-2 neutralizing antibody (NAb) levels with chemiluminescence immunoassay (CLIA) b) viral-specific interferon gamma (IFN-γ) production with enzyme-linked immunosorbent spot (ELISpot) and concentrations of CD4+ and CD8+ subpopulations [comprising CD45RA+CCR7+ (naïve), CD45RA-CCR7+ (central memory -CM-), CD45RA-CCR7- (effector memory -EM-) and CD45RA+CCR7- (effector memory re-expressing CD45RA -EMRA-, senescent) CD4+/CD8+, CD28-expressing (CD8+) and CD28-null (CD8-, senescent) CD4+/CD8+ and CD3+PD1+ (exhausted) T-cells]. At each time point, we divided patients into responders (NAb ≥ 0.3 AU/mL and/or ELISpot ≥ 30SFC/5 × 105 PBMCs) and non-responders (NAb &amp;lt; 0.3 AU/mL and ELISpot &amp;lt; 30SFC/5 × 105 PBMCs). We compared the cellular subsets’ compositions and their alterations (with regards to the differentiation-senescence and the immunoexhaustion processes) between responders and non-responders. We also examined the potential association of several other parameters with the above-mentioned cellular concentrations. Results From T1 to T2, we observed: a) in the total number of patients: an increase in T-cell EM (TEM) CD8+ concentrations and in TCM CD4+ and TEM CD8+ percentages and a drop in naïve CD4+ and CD8+ proportions, b) in responders at T1 (RT1): an ascent of TEM CD8+ numbers and of TCM CD4+ and TEM CD8+ percentages and a reduction of naïve CD4+ proportions, c) in responders at T2 (RT2): an elevation in TEM CD8+ concentrations and in TCM CD4+ percentages and a drop in naïve CD4+ counts and proportions and in TEMRA CD4+ numbers (Figs 1 and 2). At T2, responders compared to non-responders had higher concentrations of CD28+ CD4+ and CD8+ [756.34(368) vs. 446.57(925) and 227.15(166) vs. 131.44(121) cells/μL, p: 0.026 and 0.036 respectively] and greater percentages of CD28+CD4+ [93.8(6)% vs. 72.05(30.73)%, p: 0.05], as well as smaller proportions of CD28-CD4+ T-cells [6.1(5.5)% vs. 20.7(25)%, p: 0.04]. There was a negative association between age and naïve CD4+ and CD8+ T-cell and CD28+CD8+ concentrations at T1 (p: 0.042, 0.042 and 0.006, Spearman's ρ: −0.346, −0.345 and −0.444 respectively) and a positive correlation between exhausted T-cell (CD3+PD1+) numbers prior to the first vaccination and TEM / TEMRA CD4+ concentrations at T1 (p: 0.001 and 0.001, Spearman's ρ: 0.558 and 0.578 respectively), as well as TEMRA CD8+ counts at T2 (p: 0.037, Spearman's ρ: 0.396). There was also a positive association of eGFR value with TEMRA and CD28+ CD4+ counts at T1 (p: 0.021 and 0.014, Spearman's ρ: 0.389 and 0.402 respectively). Conclusion In KTRs, response to vaccination is not associated with an expansion of senescent and exhausted T-cell concentrations, but rather with a switch from naïve to differentiated-activated T-cell forms (including TEM and TCM). Age, T-cell exhaustion status at baseline and eGFR also to be correlated to the differentiation-senescence process.

Chemokine receptor 7 contributes to T- and B-cell filtering in ageing bladder, cystitis and bladder cancer

BackgroundResearch has suggested significant correlations among ageing, immune microenvironment, inflammation and tumours. However, the relationships among ageing, immune microenvironment, cystitis and bladder urothelial carcinoma (BLCA) in the bladder have rarely been reported.MethodsBladder single-cell and transcriptomic data from young and old mice were used for immune landscape analysis. Transcriptome, single-cell and The Cancer Genome Atlas Program datasets of BLCA and interstitial cystitis/bladder pain syndrome (IC/BPS) were used to analyse immune cell infiltration and molecular expression. Bladder tissues from mice, IC/BPS and BLCA were collected to validate the results.ResultsEight types of immune cells (macrophages, B-cells, dendritic cells, T-cells, monocytes, natural killer cells, γδ T-cells and ILC2) were identified in the bladder of mice. Aged mice bladder tissues had a significantly higher number of T-cells, γδ T-cells, ILC2 and B-cells than those in the young group (P < 0.05). Three types of T-cells (NK T-cells, γδ T-cells and naïve T-cells) and three types of B-cells (follicular B-cells, plasma and memory B-cells) were identified in aged mice bladder. Chemokine receptor 7 (CCR7) is highly expressed in aged bladder, IC/BPS and BLCA (P < 0.05). CCR7 is likely to be involved in T- and B-cell infiltration in aged bladder, IC/BPS and BLCA. Interestingly, the high CCR7 expression on BLCA cell membranes was a prognostic protective factor.ConclusionsIn this study, we characterised the expression profiles of immune cells in bladder tissues of aged and young mice and demonstrated that CCR7-mediated T- and B-cell filtration contributes to the development of bladder ageing, IC/BPS and BLCA.

Indicators of Immunological Status in Pregnant Women with Chronic Viral Hepatitis B and C

The work presents the results of a study of immunological indicators of cellular and humoral immunity in 45 pregnant women with chronic viral hepatitis B and C. Immunological parameters in pregnant women with CHB and CHC were characterized by suppression of the cellular component of immunity, which is manifested by a decrease in the number of total T-lymphocytes (CD3+), T-helpers (CD4+) and T-suppressors (CD8+), as well as natural killer cells (CD16), which is associated with the mechanism of maintaining pregnancy. Changes in humoral immunity are characterized by a moderate increase in the level of IgG and CEC; in case of CHC, relapse of the disease was also accompanied by an increase in class M immunoglobulins. Chronic viral hepatitis B and C in pregnant women leads to secondary immunodeficiency and an increase in the level of viral replication. A direct correlation has been revealed between indicators of the cellular immune response in CHB and CHC with the level of viral load, which must be taken into account when managing pregnancy.

Optimizing cancer therapy: a review of the multifaceted effects of metronomic chemotherapy.

Metronomic chemotherapy (MCT), characterized by the continuous administration of chemotherapeutics at a lower dose without prolonged drug-free periods, has garnered significant attention over the last 2decades. Extensive evidence from both pre-clinical and clinical settings indicates that MCT induces distinct biological effects than the standard Maximum Tolerated Dose (MTD) chemotherapy. The low toxicity profile, reduced likelihood of inducing acquired therapeutic resistance, and low cost of MCT render it an attractive chemotherapeutic regimen option. One of the most prominent aspects of MCT is its anti-angiogenesis effects. It has been shown to stimulate the expression of anti-angiogenic molecules, thereby inhibiting angiogenesis. In addition, MCT has been shown to decrease the regulatory T-cell population and promote anti-tumor immune response through inducing dendritic cell maturation and increasing the number of cytotoxic T-cells. Combination therapies utilizing MCT along with oncolytic virotherapy, radiotherapy or other chemotherapeutic regimens have been studied extensively. This review provides an overview of the current status of MCT research and the established mechanisms of action of MCT treatment and also offers insights into potential avenues of development for MCT in the future.

Enrichment of T-lymphocytes from leukemic blood using inertial microfluidics toward improved chimeric antigen receptor-T cell manufacturing

Chimeric antigen receptor cell therapy is a successful immunotherapy for the treatment of blood cancers. However, hurdles in their manufacturing remain including efficient isolation and purification of the T-cell starting material. Herein, we describe a one-step separation based on inertial spiral microfluidics for efficient enrichment of T-cells in B-cell acute lymphoblastic leukemia (ALL) and B-cell chronic lymphocytic leukemia patient's samples. In healthy donors used to optimize the process, the lymphocyte purity was enriched from 65% (SD ± 0.2) to 91% (SD ± 0.06) and T-cell purity was enriched from 45% (SD ± 0.1) to 73% (SD ± 0.02). Leukemic samples had higher starting B-cells compared to the healthy donor samples. Efficient enrichment and recovery of lymphocytes and T-cells were achieved in ALL samples with B-cells, monocytes and leukemic blasts depleted by 80% (SD ± 0.09), 89% (SD ± 0.1) and 74% (SD ± 0.09), respectively, and a 70% (SD ± 0.1) T-cell recovery. Chronic lymphocytic leukemia samples had lower T-cell numbers, and the separation process was less efficient compared to the ALL. This study demonstrates the use of inertial microfluidics for T-cell enrichment and depletion of B-cell blasts in ALL, suggesting its potential to address a key bottleneck of the chimeric antigen receptor-T manufacturing workflow.

HIV immunological non-responders are characterized by extensive immunosenescence and impaired lymphocyte cytokine production capacity.

Immunological non-responders (INR) are people living with HIV (PLHIV) who fail to fully restore CD4+ T-cell counts despite complete viral suppression with antiretroviral therapy (ART). INR are at higher risk for non-HIV related morbidity and mortality. Previous research suggest persistent qualitative defects. The 2000HIV study (clinical trials NTC03994835) enrolled 1895 PLHIV, divided in a discovery and validation cohort. PLHIV with CD4 T-cell count <350 cells/mm3 after ≥2 years of suppressive ART were defined as INR and were compared to immunological responders (IR) with CD4 T-cell count >500 cells/mm3. Logistic and rank based regression were used to analyze clinical data, extensive innate and adaptive immunophenotyping, and ex vivo monocyte and lymphocyte cytokine production after stimulation with various stimuli. The discovery cohort consisted of 62 INR and 1224 IR, the validation cohort of 26 INR and 243 IR. INR were older, had more advanced HIV disease before starting ART and had more frequently a history of non-AIDS related malignancy. INR had lower absolute CD4+ T-cell numbers in all subsets. Activated (HLA-DR+, CD38+) and exhausted (PD1+) subpopulations were proportionally increased in CD4 T-cells. Monocyte and granulocyte immunophenotypes were comparable. INR lymphocytes produced less IL-22, IFN-γ, IL-10 and IL-17 to stimuli. In contrast, monocyte cytokine production did not differ. The proportions of CD4+CD38+HLA-DR+ and CD4+PD1+ subpopulations showed an inversed correlation to lymphocyte cytokine production. INR compared to IR have hyperactivated and exhausted CD4+ T-cells in combination with lymphocyte functional impairment, while innate immune responses were comparable. Our data provide a rationale to consider the use of anti-PD1 therapy in INR.

P311 KO Mice are Protected from Experimentally Induced Lung Fibrosis

Pulmonary fibrosis (PF) is a fatal chronic interstitial lung disease and one of the most irreversible forms of tissue/organ fibrosis. Idiopathic pulmonary fibrosis is a very progressive disease accompanied by inflammatory damage with a median survival of less than 5 years. Etiology of IPF is still elusive with potential reasons being genetic predisposition and environmental exposures including particulates, radiation, and SARS-CoV-2. Recent studies indicate that about 50% of COVID19 associated acute respiratory distress syndrome survivors develop PF. There are very limited treatment options with no curative therapies available for PF apart from invasive lung transplantation. P311 is an 8 kDa protein previously shown to have a key role in lung regeneration. As P311 overexpression in fibroblasts induced myofibroblast phenotype, we hypothesized that P311 has a role in tissue fibrosis. We induced PF by intra-tracheally instilling bleomycin (BL) in P311 knockout (KO) mice and wild type (WT, C57BL/6) control mice and collected lungs after 2-5 weeks. P311 KO mice showed significantly less fibrosis. After intra-tracheal instillation of BL, the lungs of P311 KO mice (D21) had significantly reduced number of myofibroblasts as indicated by reduced SM α-actin expression and collagen deposition as indicated by Masson trichrome staining compared to their WT counterparts. We further observed reduced levels of TGF-β1-3 and Smad-2 and -3 along with decreased epithelial to mesenchymal transdifferentiation markers in the lungs of bleomycin treated P311 KOs compared to WT controls. Further bronchoalveolar lavage fluid (BALF) was collected (D14) and utilized to determine the pulmonary inflammation by determining the total and different immune cell populations in the BALF and lung samples by FACS analysis. Even though we saw a significant increase in the BALF cellularity, we did not observe significant changes in T-cell, macrophage, and neutrophil numbers between WT and P311KOs. However, lung cell isolates showed significantly increased CD3 and CD4 positive cells indicating increased T-cells and helper T-cells in fibrotic P311KO lungs compared to WT lungs. In conclusion, bleomycin administration resulted in lung fibrosis in WT mice, but P311 KO mice are protected. This study was partially supported by research funding to KB, from American Lung Association, DA-196629-N. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

T-Cell Characteristics Impact Response and Resistance to T-Cell-Redirecting Bispecific Antibodies in Multiple Myeloma.

Bispecific antibodies (BsAb) directed against B-cell maturation antigen (teclistamab) or the orphan G protein-coupled receptor GPRC5D (talquetamab) induce deep and durable responses in heavily pretreated patients with multiple myeloma. However, mechanisms underlying primary and acquired resistance remain poorly understood. The anti-multiple myeloma activity of teclistamab and talquetamab was evaluated in bone marrow (BM) samples from patients with multiple myeloma. T-cell phenotype and function were assessed in BM/peripheral blood samples obtained from patients with multiple myeloma who were treated with these BsAb. In ex vivo killing assays with 41 BM samples from BsAb-naive patients with multiple myeloma, teclistamab- and talquetamab-mediated multiple myeloma lysis was strongly correlated (r = 0.73, P < 0.0001). Both BsAb exhibited poor activity in samples with high regulatory T-cell (Treg) numbers and a low T-cell/multiple myeloma cell ratio. Furthermore, comprehensive phenotyping of BM samples derived from patients treated with teclistamab or talquetamab revealed that high frequencies of PD-1+ CD4+ T cells, CTLA4+ CD4+ T cells, and CD38+ CD4+ T cells were associated with primary resistance. Although this lack of response was linked to a modest increase in the expression of inhibitory receptors, increasing T-cell/multiple myeloma cell ratios by adding extra T cells enhanced sensitivity to BsAb. Further, treatment with BsAb resulted in an increased proportion of T cells expressing exhaustion markers (PD-1, TIGIT, and TIM-3), which was accompanied by reduced T-cell proliferative potential and cytokine secretion, as well as impaired antitumor efficacy in ex vivo experiments. Primary resistance is characterized by a low T-cell/multiple myeloma cell ratio and Treg-driven immunosuppression, whereas reduced T-cell fitness due to continuous BsAb-mediated T-cell activation may contribute to the development of acquired resistance.

Стан імунної та ендокринної систем у мишей із різним гаплотипом Н-2 та його потенційний зв’язок із проявами експериментального паркінсонізму

In male mice of the strains FVB/N (haplotype H-2q) and 129/Sv (haplotype H-2b) aged 6-7 months, estimated indicators of the functioning of the thymus, bone marrow, spleen, pineal gland and adrenal glands, the number of CD3+ (Tlymphocytes ) and CD11b+ (macrophages) cells in the brain, and also studied the characteristics of changes in the values of indicators after administration of neurotoxin 1-methyl4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to such mice (reproduction of parkinsonism). We have found that in intact mice of the FVB/N strain the thymulin level in the blood and the mass and cellularity of the thymus are lower, and the number of CD3+ cells, colony-forming progenitor cells for fibroblasts and granulocytes-macrophages in the bone marrow are greater than in mice of the 129/Sv strain. The number of CD3+ and CD11b+ cells in the brain of FVB/N strain mice exceeds their value in 129/Sv strain mice by 1.6 and 2.2 times, respectively. The level of melatonin in the blood of mice of the FVB/N strain was 2.4 times lower than in mice of the 129/Sv strain, while the mass of the adrenal glands was greater. The in vitro experiments have shown a decrease of the thymulin level in the supernatant of the cultured thymus stroma after incubation with corticosterone in mice of the 129/ Sv strain (from 5.8 ± 0.6 to 3.8 ± 0.4, log2) and no changes in the indicator in mice of the FVB/N strain. 18 days after MPTP administration there was a drop in the blood thymulin level, in the mass and cellularity of the spleen in mice of the 129/Sv strain, a decrease in the mass and cellularity of the thymus in mice of both strains, and an increase in the mass of the adrenal glands in mice of the FVB/N strain. Under the influence of the neurotoxin, the proportion of CD3+ cells in the brain of mice of the FVB/N strain has significantly increased compared to the control group, while in the mice of the 129/Sv strain the proportion of CD11b+ cells has increased significantly. Thus, the haplotype H-2 of mice has affected the functioning of the central and peripheral organs of the immune and endocrine systems, the number of T-lymphocytes and macrophages in the brain as well as the manifestations of changes in indicators after MFTP administration, which may be important for the formation of feature of morphofunctional disorders in the nervous system in such animals.

25-Hydroxycholesterol regulates lysosome AMP kinase activation and metabolic reprogramming to educate immunosuppressive macrophages

Macrophages are critical to turn noninflamed "cold tumors" into inflamed "hot tumors". Emerging evidence indicates abnormal cholesterol metabolites in the tumor microenvironment (TME) with unclear function. Here, we uncovered the inducible expression of cholesterol-25-hydroxylase (Ch25h) by interleukin-4 (IL-4) and interleukin-13 (IL-13) via the transcription factor STAT6, causing 25-hydroxycholesterol (25HC) accumulation. scRNA-seq analysis confirmed that CH25Hhi subsets were enriched in immunosuppressive macrophage subsets and correlated to lower survival rates in pan-cancers. Targeting CH25H abrogated macrophage immunosuppressive function to enhance infiltrating Tcell numbers and activation, which synergized with anti-PD-1 to improve anti-tumor efficacy. Mechanically, lysosome-accumulated 25HC competed with cholesterol for GPR155 binding to inhibit the kinase mTORC1, leading to AMPKα activation and metabolic reprogramming. AMPKα also phosphorylated STAT6 Ser564 to enhance STAT6 activation and ARG1 production. Together, we propose CH25H as an immunometabolic checkpoint, which manipulates macrophage fate to reshape CD8+ Tcell surveillance and anti-tumor response.

Prognostic Significance of T-Cells and Macrophages in the Tumour Microenvironment of Nodal DLBCL.

Revised International Prognostic (R-IPI) score is used widely for risk stratification of DLBCL cases, yet some patients belonging to same risk category tend to exhibit different outcomes. The role of T-cells and macrophages in prognostication of lymphomas has been a point of interest of late. We aimed to study the association of FOXP3 positive T-regulatory cells, cytotoxic T-cells and macrophages with the immunophenotypic subtypes, clinicopathological characteristics, treatment response and survival in nodal diffuse large B-cell lymphoma (DLBCL) patients. The clinicopathological and treatment data of 83 DLBCL patients diagnosed and treated at our institute from January 2015 to December 2018 were collected and followed up till June 2020. CD8, FOXP3 and CD68 immunostains were performed to highlight the cytotoxic T-cells, T-regulatory cells and macrophages respectively on the lymph node biopsies and the distribution of these cells and their association with clinico-pathological factors, treatment response and survival was analyzed. DLBCL cases with higher percentage of CD3 positive T-cells and CD8 positive cytotoxic T-cells had significant association with attainment of complete response to treatment. In addition, CD8 positive T-cells of more than 6.5% proved to be an independent predictor of treatment outcome (p = 0.022). Multivariate Cox regression survival analysis revealed that cases with 'good' R-IPI prognostic score and 'high CD68 positive macrophages in tumor microenvironment' had a significantly longer overall survival. Increased number of cytotoxic T-cells was significantly associated with complete response to treatment and higher number of macrophages correlated significantly with better overall survival signifying their antitumor effects.

Abstract CT208: High tumor monocyte content predicts long-term survival for patients with operable oesophageal cancer treated with neoadjuvant immunochemotherapy in the LUD2015-005 trial

Abstract Background: Combined immune checkpoint inhibitors (ICI) with chemotherapy in advanced oesophageal cancer (OC) has shown survival benefit in phase III studies, resulting in ICI’s recent approval to treat advanced OC. The role of ICI in peri-operative OC is debated, and large clinical studies are ongoing. Patients’ response to immunochemotherapy is highly variable and it is unclear what underlies this heterogeneity. To address this challenge, 38 advanced and 35 operable OC patients were enrolled to receive ICI in the LUD2015-005 trial (NCT02735239). Methods: We investigated the clinical and biological effects of adding the anti-PD-L1 ICI durvalumab to peri-operative chemotherapy or chemoradiotherapy (CRT) in a phase II multicentre study (LUD2015-005 trial). Operable OC patients received ICI for four weeks, followed by combination treatment with ICI + chemotherapy (oxaliplatin and capecitabine or fluorouracil, leucovorin, oxaliplatin, and docetaxel (FLOT)), or ICI + CRT (CROSS regimen). Patients could also receive ICI for up to 6 months after surgery. Tissue samples were collected at baseline, after four weeks ICI-only, and on the day of surgery. Further to assessing synergy of ICI with standard peri-operative treatment for OC, our trial design enables an in-depth analysis of molecular features of response, and to dissect the impact of ICI alone on the tumor microenvironment. Single cell and bulk transcriptomic data were generated and used to perform RNA deconvolution to estimate tumor cell composition. Results: The treatment was well-tolerated and two-year survival was 80% and 73.3% with ICI + chemotherapy and ICI + CRT, respectively. Survival was superior to that of propensity score matched patients receiving standard of care (p = 0.047). Tumor cell composition analysis revealed that neither total T-cell numbers nor a specific T-cell functional phenotype was associated with outcome, but high tumor monocyte content (TMC) at baseline was highly predictive of overall survival (p = 0.003). Moreover, a 13-gene core monocyte gene signature was sufficient to predict overall survival (p = 0.022) and major pathological response (mPR, Mandard 1-2, p = 0.009). Patients with mPR at resection showed enrichment of interferon and IL15 signalling at the four-week ICI-only timepoint (p &amp;lt; 0.001). Single cell trajectory interference combined with immune response enrichment analysis also show that high interferon and IL15 signalling drive monocytes to differentiate into M1 macrophages and dendritic cells. Conclusion: Similar to our previous finding in immunochemotherapy treated advanced OC patients (Carroll et al. Cancer Cell 2023), TMC is a highly predictive biomarker of long-term survival for operable OC patients treated with neoadjuvant immunochemotherapy, highlighting the importance of tumor monocytes and their differentiation potential in OC patients’ response to ICI. Citation Format: Hannah S. Fuchs, Sabrina A. James, Thomas M. Carroll, Phil F. Xie, Joseph A. Chadwick, Duncan Parkes, Simon R. Lord, Lucinda Griffiths, Tim Underwood, Ioannis Karydis, Russell T. Petty, Benjamin Schuster-Böckler, Richard P. Owen, Mark R. Middleton, Xin Lu. High tumor monocyte content predicts long-term survival for patients with operable oesophageal cancer treated with neoadjuvant immunochemotherapy in the LUD2015-005 trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT208.

Effect of 2-methoxyestradiol on mammary tumor initiation and progression.

The anti-cancer agent 2-methoxyestradiol (2-ME) has been shown to have anti-proliferative and anti-angiogenic properties. Previously, the effect of 2-ME on early- and late-stage breast cancer (BC) was investigated in vivo using a transgenic mouse model (FVB/N-Tg(MMTV-PyVT)) of spontaneous mammary carcinoma. Anti-tumor effects were observed in late-stage BC with no effect on early-stage BC. Given the contrasting results obtained from the different BC stages, we have now investigated the effect of 2-ME when administered before the appearance of palpable tumors. Each mouse received 100 mg/kg 2-ME on day 30 after birth, twice per week for 28 days, while control mice received vehicle only. Animals were terminated on day 59. Lung and mammary tissue were obtained for immunohistochemical analysis of CD163 and CD3 expression, and histological examination was performed to analyze tumor necrosis. Additionally, blood samples were collected to measure plasma cytokine levels. 2-ME increased tumor mass when compared to the untreated animals (p = .0139). The pro-tumorigenic activity of 2-ME was accompanied by lower CD3+ T-cell numbers in the tumor microenvironment (TME) and high levels of the pro-inflammatory cytokine interleukin (IL)-1β. Conversely, 2-ME-treatment resulted in fewer CD163+ cells detectable in the TME, increased levels of tumor necrosis, increased IL-10 plasma levels, and low IL-6 and IL-27 plasma levels. Taken together, these findings suggest that 2-ME promotes early-stage BC development.