MO695THE ASSOCIATION OF CIRCULATING CD14++CD16+ MONOCYTES, NATURAL KILLER CELLS AND REGULATORY T CELLS SUBPOPULATIONS WITH CARDIOVASCULAR DISEASE IN A COHORT OF PERITONEAL DIALYSIS PATIENTS

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Anila Duni ◽  
Olga Balafa ◽  
George Vartholomatos ◽  
Margarita Oikonomou ◽  
Paraskevi Tseke ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
T Cells ◽  
Peritoneal Dialysis ◽  
Nk Cells ◽  
Immune Cells ◽  
Immune Cell ◽  
Normal Range ◽  
Immune Cell Subsets ◽  
Cell Subpopulations

Abstract Background and Aims Advanced chronic kidney disease (CKD) is characterized by elevated expression of the proinflammatory and pro-atherogenic CD14++CD16+ monocytes subset. The role of lymphocyte subpopulations including natural killer (NK) cells and CD4+CD25+ regulatory T cells (Tregs) in the modulation of inflammation and immunity and subsequent cardiovascular implications have received increasing attention. The role of immune cell subpopulations remains to be determined in peritoneal dialysis (PD) patients. The aim of this pilot study was to investigate potential correlations between blood levels of CD14++CD16+ monocytes, NK cells and Tregs with phenotypes of established cardiovascular disease (CVD), including coronary artery disease (CAD) and heart failure (HF) in a cohort of PD patients. Method 29 stable PD patients (mean age 66.96 years ±14.5, 62% males) were enrolled. Exclusion criteria were a history of malignancy, autoimmune disease, active or chronic infections and a recent (< 3 months) cardiovascular event. Demographic, laboratory and bioimpedance measurements data (overhydration, extracellular and total body water and their ratios) were collected. The analysis of peripheral blood immune cell subsets was performed using flow cytometry (FC). Additionally, in 7 PD patients the distribution of the immune cells was evaluated by FC at two time points: T0 (before initiation of PD - CKD stage G5) and T1 (after PD start). Results The median dialysis vintage was 34.5 (range 3.2-141) months. Overall, PD patients had 527 ± 199 monocytes and 1731 ± 489 lymphocytes while mean percentage of CD14++CD16+ monocytes was 9.3 ±6.36% (normal range 2-8%), NK cells 16.6±10.3% (normal range 5-15%) and Tregs 2.1±1.76% (normal range 1-3%). There was no correlation of either of these cell subpopulations with age, PD vintage, inflammation markers (CRP, fibrinogen, albumin, hsTroponin-I), overhydration markers or comorbidities. Only increased NK cells were associated with the presence of HF in PD (24.87 vs 14.92%, p 0.047). In multiple regression analysis, NK cells levels were strongly associated with the presence of edema (beta coef=13.7, p<0.001) and CAD (beta coef=7.1, p=0.046). At T0 mean percentage of CD14++CD16+ monocytes, NK cells and Tregs were 9.7 ±4.5%, 17.1 ±3.84% and 2.38± 1.26% respectively whereas at T1 mean percentage of CD14++CD16+ monocytes was 13.3% ±8.4, NK cells 19.8±6.47% and Tregs 1.5±0.6%. Paired t-test of cell subpopulations (T0 vs T1) showed that only the Tregs were significantly decreased (p =0.018), while the other subpopulations did not differ and remained increased. Conclusion Our study is the first to evaluate the potential association between specific immune cell subsets and cardiovascular disease in long-term PD patients. Increased NK cells levels directly correlate both with the presence of HF and CAD in PD patients. Longitudinal results suggest that CD14++CD16+ and NK cells remain increased after PD start, while Tregs decrease further. The state of pro-inflammation and immune deregulation appear to persist after initiating PD. Future research is required to evaluate the role of immune cells subsets as potential tools to identify patients who are at the highest risk for complications and to guide interventions that may improve clinical outcomes.

scholarly journals A2bR-dependent signaling alters immune cell composition and enhances IL-6 formation in the ischemic heart

2019 ◽  
Vol 317 (1) ◽  
pp. H190-H200 ◽  
Author(s):  
Christina Alter ◽  
Zhaoping Ding ◽  
Ulrich Flögel ◽  
Jürgen Scheller ◽  
Jürgen Schrader
Keyword(s):  
T Cells ◽  
B Cells ◽  
Regulatory T Cells ◽  
Nk Cells ◽  
Immune Cells ◽  
Cardiac Remodeling ◽  
Immune Cell ◽  
Ischemic Heart ◽  
Cell Composition ◽  
Immune Cell Subsets

Although the cardioprotective effect of adenosine is undisputed, the role of the adenosine A2breceptor (A2bR) in ischemic cardiac remodeling is not defined. In this study we aimed to unravel the role A2bR plays in modulating the immune response and the healing mechanisms after myocardial infarction. Genetic and pharmacological (PSB603) inactivation of A2bR as well as activation of A2bR with BAY60-6583 does not alter cardiac remodeling of the infarcted (50-min left anterior descending artery occlusion/reperfusion) murine heart. Flow cytometry of immune cell subsets identified a significant increase in B cells, NK cells, CD8 and CD4 T cells, as well as FoxP3-expressing regulatory T cells in the injured heart in A2bR-deficient mice. Analysis of T-cell function revealed that expression and secretion of interleukin (IL)-2, interferon (IFN)γ, and tumor necrosis factor (TNF)α by T cells is under A2bR control. In addition, we found substantial cellular heterogeneity in the response of immune cells and cardiomyocytes to A2bR deficiency: while in the absence of A2bR, expression of IL-6 was greatly reduced in cardiomyocytes and immune cells except T cells, and expression of IL-1β was strongly reduced in cardiomyocytes, granulocytes, and B cells as determined by quantitative PCR. Our findings indicate that A2bR signaling in the ischemic heart triggers substantial changes in cardiac immune cell composition of the lymphoid lineage and induces a profound cell type-specific downregulation of IL-6 and IL-1β. This suggests the presence of a targetable adenosine–A2bR–IL-6-axis triggered by adenosine formed by the ischemic heart.NEW & NOTEWORTHY Genetic deletion and pharmacological inactivation/activation of A2bR does not alter cardiac remodeling after MI but is associated by compensatory upregulation of various pro- and anti-inflammatory immune cell subsets (B cells, NK cells, CD8 and CD4 T cells, regulatory T cells). In the inflamed heart, A2bR modulates the expression of IL-2, IFNγ, TNFα in T cells and of IL-6 in cardiomyocytes, monocytes, granulocytes and B cells. This suggests an important adenosine–IL-6 axis, which is controlled by A2bR via local adenosine.

Immunological Effects and Predictive Gene Signatures in Patients with Relapsed Follicular Lymphoma Treated with CT-011, a Humanized Anti-PD-1 Monoclonal Antibody

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 162-162
Author(s):  
Fuliang Chu ◽  
Jason R. Westin ◽  
Min Zhang ◽  
Lei Feng ◽  
Veerabhadran Baladandayuthapani ◽  
...  
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Immune Cells ◽  
Cd4 T Cells ◽  
Research Funding ◽  
Immune Cell ◽  
Gene Signature ◽  
Effector Memory ◽  
Core Needle ◽  
Immune Cell Subsets

Abstract Abstract 162 Background: The coinhibitory receptor programmed death (PD)-1 is markedly increased on peripheral blood (PB) and intratumoral T cells in follicular lymphoma (FL) and is associated with impaired T-cell function. CT-011 (pidilizumab), a humanized anti PD-1 monoclonal antibody, blocks the PD-1/PD-ligand pathway and enhances the function of antitumor T and NK cells. We conducted a phase II trial to determine the safety and efficacy of CT-011 and rituximab in patients (pts) with relapsed FL and the clinical results are reported separately. Here, we evaluated the effects of CT-011 on immune cells both in the PB and tumor microenvironment. We also determined predictors of clinical outcome based on PB immune cell subsets and molecular features of tumor-infiltrating immune cells at baseline. Methods: CT-011 was given every 4 wks × 4 and rituximab weekly × 4 starting on day 17 after the first infusion of CT-011. Pts with response or stable disease received 8 additional optional infusions of CT-011 every 4 wks. PB and core needle biopsies from involved lymph nodes were collected prior to and on day 14 after the first infusion of CT-011. PB mononuclear cells (PBMC) were analyzed by multiparametric flow cytometry to determine various immune cell subsets. Whole genome gene expression profiling (GEP) was performed on core needle biopsies. Results: Of 29 pts eligible for efficacy analysis, 19 had an objective response for an ORR of 66%. CR was observed in 15 (52%) and PR in 4 (14%). After a median follow up of 14 mo, median PFS was 21.1 mo, and was not reached for the responders. We observed a significant increase in the absolute number of PB immune cells in day 14 samples compared with baseline including total lymphocyte count (p<0.01), CD3+ T cells (p=0.01), CD4+ T cells (p<0.01), and CD4+ naive (p=0.01), effector memory (p=0.02), and central memory T cells (p<0.05). We also observed increase in the expression of the activating receptor NKG2D on NK cells (p=0.01). In contrast, CD8+ terminally differentiated T cells were decreased (p=0.02). Comparison of GEP from core needle biopsies obtained pretreatment and day 14 (n=8 pairs) showed up regulation of several genes associated with T cell activation in day 14 samples including CD58, CTLA4, NFATC1, CCR5, PBK, TSLP, and ZBTB32. We analyzed GEP of baseline tumor biopsies from 18 pts to find gene signatures that correlated with clinical outcome, as measured by PFS and/or quantitative change in tumor size (%change). We tested a “PD-1hi_Down” signature of 41 genes previously reported by us (Chu et al, Blood, Nov 2011; 118:2648) to be less expressed in CD4+ T cells strongly positive for PD-1, likely to be follicular helper T cells (Tfh, PD-1hi), than in CD4+ T cells with intermediate or low levels of PD-1 surface staining, likely to be exhausted effector T cells (Teffs, PD-1int) or activated effector or naïve T cells (PD-1lo). The PD-1hi_Down gene signature correlated significantly with PFS by univariate Cox regression and was also significant when examined by gene set enrichment analysis based on ranking all genes by correlation with %change. Low expression of this signature, suggesting more Tfh and fewer PD-1+ Teffs within the tumor, predicted shorter PFS duration and less tumor shrinkage. Combined with our in vitro findings that anti-PD-1 Ab enhances the function of Tfh and PD-1+ Teffs but has no effect on PD-1lo T cells in FL, these results suggest that CT-011 therapy enhances the respective pro- and anti-tumor effects of one or both of these cell types. In support of our conclusion that the effect of the PD-1hi_Down signature on outcome depends on CT-011 therapy, we found that this signature did not correlate with overall survival in an external dataset of FL pts treated largely with chemotherapy alone (Dave et al., NEJM 2004; 351: 2109). Conclusions: Administration of CT-011 (pidilizumab) was associated with increase in the numbers of naïve, effector memory, and central memory CD4+ T cells and resulted in activation of T and NK cells in the PB and the tumor microenvironment in FL. A high expression of PD-1hi_Down gene signature, consistent with relatively increased numbers of antitumor Teffs compared with protumor Tfh was predictive of good response and improved PFS suggesting that CT-011 restores function of exhausted Teffs. These results provide insight into the mechanism of action of CT-011 and offer a predictive biomarker for selection of pts for future clinical trials with this class of agents in FL. Disclosures: Rotem-Yehudar: CureTech Ltd: Employment, Research Funding. Neelapu:Cure Tech, Ltd.: Research Funding.

scholarly journals Immune Monitoring during Therapy Reveals Activitory and Regulatory Immune Responses in High-Risk Neuroblastoma

Cancers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 2096
Author(s):  
Celina L. Szanto ◽  
Annelisa M. Cornel ◽  
Sara M. Tamminga ◽  
Eveline M. Delemarre ◽  
Coco C. H. de Koning ◽  
...  
Keyword(s):  
T Cells ◽  
High Risk ◽  
Nk Cells ◽  
Immune Cell ◽  
High Dose Chemotherapy ◽  
Immune Monitoring ◽  
High Dose ◽  
Effector Cells ◽  
Gm Csf ◽  
Immune Cell Subsets

Despite intensive treatment, including consolidation immunotherapy (IT), prognosis of high-risk neuroblastoma (HR-NBL) is poor. Immune status of patients over the course of treatment, and thus immunological features potentially explaining therapy efficacy, are largely unknown. In this study, the dynamics of immune cell subsets and their function were explored in 25 HR-NBL patients at diagnosis, during induction chemotherapy, before high-dose chemotherapy, and during IT. The dynamics of immune cells varied largely between patients. IL-2- and GM-CSF-containing IT cycles resulted in significant expansion of effector cells (NK-cells in IL-2 cycles, neutrophils and monocytes in GM-CSF cycles). Nonetheless, the cytotoxic phenotype of NK-cells was majorly disturbed at the start of IT, and both IL-2 and GM-CSF IT cycles induced preferential expansion of suppressive regulatory T-cells. Interestingly, proliferative capacity of purified patient T-cells was impaired at diagnosis as well as during therapy. This study indicates the presence of both immune-enhancing as well as regulatory responses in HR-NBL patients during (immuno)therapy. Especially the double-edged effects observed in IL-2-containing IT cycles are interesting, as this potentially explains the absence of clinical benefit of IL-2 addition to IT cycles. This suggests that there is a need to combine anti-GD2 with more specific immune-enhancing strategies to improve IT outcome in HR-NBL.

scholarly journals Tuning cancer fate: the unremitting role of host immunity

Open Biology ◽  
2017 ◽  
Vol 7 (4) ◽  
pp. 170006 ◽  
Author(s):  
B. Calì ◽  
B. Molon ◽  
A. Viola
Keyword(s):  
Immune Cells ◽  
Immune Cell ◽  
Tumour Progression ◽  
Host Immunity ◽  
Adaptive Immune ◽  
Adaptive Immune Cells ◽  
Immune Mediated ◽  
Immune Cell Subsets ◽  
Therapeutic Protocols

Host immunity plays a central and complex role in dictating tumour progression. Solid tumours are commonly infiltrated by a large number of immune cells that dynamically interact with the surrounding microenvironment. At first, innate and adaptive immune cells successfully cooperate to eradicate microcolonies of transformed cells. Concomitantly, surviving tumour clones start to proliferate and harness immune responses by specifically hijacking anti-tumour effector mechanisms and fostering the accumulation of immunosuppressive immune cell subsets at the tumour site. This pliable interplay between immune and malignant cells is a relentless process that has been concisely organized in three different phases: elimination, equilibrium and escape. In this review, we aim to depict the distinct immune cell subsets and immune-mediated responses characterizing the tumour landscape throughout the three interconnected phases. Importantly, the identification of key immune players and molecules involved in the dynamic crosstalk between tumour and immune system has been crucial for the introduction of reliable prognostic factors and effective therapeutic protocols against cancers.

scholarly journals Immune cell composition in normal human kidneys

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jun-Gyu Park ◽  
Myeongsu Na ◽  
Min-Gang Kim ◽  
Su Hwan Park ◽  
Hack June Lee ◽  
...  
Keyword(s):  
T Cells ◽  
Immune Cells ◽  
Immune Cell ◽  
Kidney Diseases ◽  
Myeloid Cells ◽  
Human Kidney ◽  
Effector Memory ◽  
Immune Cell Subsets ◽  
Immunological Mechanisms ◽  
Normal Human

Abstract An understanding of immunological mechanisms in kidney diseases has advanced using mouse kidneys. However, the profiling of immune cell subsets in human kidneys remains undetermined, particularly compared with mouse kidneys. Normal human kidneys were obtained from radically nephrectomised patients with urogenital malignancy (n = 15). Subsequently, human kidney immune cell subsets were analysed using multicolor flow cytometry and compared with subsets from C57BL/6 or BALB/c mice under specific pathogen-free conditions. Twenty kidney sections from healthy kidney donors or subjects without specific renal lesions were additionally analysed by immunohistochemistry. In human kidneys, 47% ± 12% (maximum 63%) of immune cells were CD3+ T cells. Kidney CD4+ and CD8+ T cells comprised 44% and 56% of total T cells. Of these, 47% ± 15% of T cells displayed an effector memory phenotype (CCR7− CD45RA− CD69−), and 48% ± 19% were kidney-resident cells (CCR7− CD45RA− CD69+). However, the proportions of human CD14+ and CD16+ myeloid cells were approximately 10% of total immune cells. A predominance of CD3+ T cells and a low proportion of CD14+ or CD68+ myeloid cells were also identified in healthy human kidney sections. In mouse kidneys, kidney-resident macrophages (CD11blow F4/80high) were the most predominant subset (up to 50%) but the proportion of CD3+ T cells was less than 20%. These results will be of use in studies in which mouse results are translated into human cases under homeostatic conditions or with disease.

scholarly journals Global immune characterization of HBV/HCV-related hepatocellular carcinoma identifies macrophage and T-cell subsets associated with disease progression

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Guohe Song ◽  
Yang Shi ◽  
Meiying Zhang ◽  
Shyamal Goswami ◽  
Saifullah Afridi ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
T Cells ◽  
T Cell ◽  
Single Cell ◽  
Immune Cells ◽  
Immune Cell ◽  
T Cell Subsets ◽  
M2 Macrophage ◽  
Advanced Hcc ◽  
Immune Cell Subsets

AbstractDiverse immune cells in the tumor microenvironment form a complex ecosystem, but our knowledge of their heterogeneity and dynamics within hepatocellular carcinoma (HCC) still remains limited. To assess the plasticity and phenotypes of immune cells within HBV/HCV-related HCC microenvironment at single-cell level, we performed single-cell RNA sequencing on 41,698 immune cells from seven pairs of HBV/HCV-related HCC tumors and non-tumor liver tissues. We combined bio-informatic analyses, flow cytometry, and multiplex immunohistochemistry to assess the heterogeneity of different immune cell subsets in functional characteristics, transcriptional regulation, phenotypic switching, and interactions. We identified 29 immune cell subsets of myeloid cells, NK cells, and lymphocytes with unique transcriptomic profiles in HCC. A highly complex immunological network was shaped by diverse immune cell subsets that can transit among different states and mutually interact. Notably, we identified a subset of M2 macrophage with high expression of CCL18 and transcription factor CREM that was enriched in advanced HCC patients, and potentially participated in tumor progression. We also detected a new subset of activated CD8+ T cells highly expressing XCL1 that correlated with better patient survival rates. Meanwhile, distinct transcriptomic signatures, cytotoxic phenotypes, and evolution trajectory of effector CD8+ T cells from early-stage to advanced HCC were also identified. Our study provides insight into the immune microenvironment in HBV/HCV-related HCC and highlights novel macrophage and T-cell subsets that could be further exploited in future immunotherapy.

Mezagitamab Induces Immunomodulatory Effect in Patients with Relapsed/Refractory Multiple Myeloma (RRMM)

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 9-9
Author(s):  
Michael Abadier ◽  
Jose Estevam ◽  
Deborah Berg ◽  
Eric Robert Fedyk
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
B Cells ◽  
Nk Cells ◽  
Peripheral Blood ◽  
Immune Cell ◽  
Cell Populations ◽  
Landscape Changes ◽  
Ki 67 ◽  
Immune Cell Subsets

Background Mezagitamab is a fully human immunoglobulin (Ig) G1 monoclonal antibody with high affinity to CD38 that depletes tumor cells expressing CD38 by antibody- and complement-dependent cytotoxicity. CD38 is a cell surface molecule that is highly expressed on myeloma cells, plasma cells, plasmablasts, and natural killer (NK) cells, and is induced on activated T cells and other suppressor cells including regulatory T (Tregs) and B (Bregs) cells. Data suggest that immune landscape changes in cancer patients and this may correlate with disease stage and clinical outcome. Monitoring specific immune cell subsets could predict treatment responses since certain cell populations either enhance or attenuate the anti-tumor immune response. Method To monitor the immune landscape changes in RRMM patients we developed a mass cytometry panel that measures 39-biomarkers to identify multiple immune cell subsets, including T cells (naïve, memory, effector, regulatory), B cells (naïve, memory, precursors, plasmablasts, regulatory), NK cells, NKT cells, gamma delta T cells, monocytes (classical, non-classical and intermediate), dendritic cells (mDC; myeloid and pDC; plasmacytoid) and basophils. After a robust analytical method validation, we tested cryopreserved peripheral blood and bone marrow mononuclear cells from 19 RRMM patients who received ≥ 3 prior lines of therapy. Patients were administered 300 or 600 mg SC mezagitamab on a QWx8, Q2Wx8 and then Q4Wx until disease progression schedule (NCT03439280). We compared the percent change in immune cell subsets at baseline versus week 4 and week 16. Results CD38 is expressed at different levels on immune cells and sensitivity to depletion by mezagitamab generally correlates positively with the density of expression. CD38 is expressed at high densities on plasmablasts, Bregs, NK-cells, pDC and basophils at baseline and this was associated with reductions in peripheral blood and bone marrow (plasmablasts, 95%, Bregs, 90%, NK-cells, 50%, pDC, 55% and basophils, 40%) at week 4 post treatment. In contrast, no changes occurred in the level of total T-cells and B-cells, which is consistent with low expression of CD38 on most cells of these large populations. Among the insensitive cell types, remaining NK-cells acquired an activated, proliferative and effector phenotype. We observed 60-150% increase in activation (CD69, HLA-DR), 110-200% increase in proliferation (Ki-67), and 40-375% increase in effector (IFN-γ) markers in peripheral blood and bone marrow. Importantly, NK-cells which did not express detectable CD38, also exhibited a similar phenotype possibly by a mechanism independent of CD38. Consistent with these data, the remaining CD4 and CD8 T-cell populations exhibited an activated effector phenotype as observed by 40-200% increase in activation, 60-200% increase in proliferation and 40-90% increase in effector markers in peripheral blood. A potential explanation for this acquisition of activated effector phenotypes could be a reduction in suppressive regulatory lymphocytes. Next, we measured levels of Tregs and Bregs, and observed that Bregs which are CD24hiCD38hi were reduced to 60-90% in peripheral blood and bone marrow. In contrast, total Tregs were reduced by only 5-25% because CD38 expression in Tregs appears as a spectrum where only ~10-20% are CD38+, and thus CD38+ Tregs were reduced more significantly (45-75%), reflecting the selectively of mezagitamab to cells expressing high levels of CD38. CD38+ Tregs are induced in RRMM patients, thus we looked at the phenotype of CD38-, CD38mid, and CD38high -expressing Tregs. We observed higher level of markers that correlate with highly suppressive Tregs such as Granzyme B, Ki-67, CTLA-4 and PD-1 in CD38high Tregs. Accordingly, the total Treg population exhibited a less active phenotype after exposure to mezagitamab, which selectively depleted the highly suppressive CD38+ Tregs. Conclusions Chronic treatment with mezagitamab is immunomodulatory in patients with RRMM, which is associated with reductions in tumor burden, subpopulations of B and T regulatory cells, and characterized by conventional NK and T cells exhibiting an activated, proliferative and effector phenotype. The immune landscape changes observed is consistent with the immunologic concept of converting the tumor microenvironment from cold-to-hot and highlights a key mechanistic effect of mezagitamab. Disclosures Berg: Takeda Pharmaceuticals Inc: Current Employment.

scholarly journals Key Immune Cell Subsets Are Dysregulated in Patients with Myelofibrosis

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 5580-5580
Author(s):  
Marco Romano ◽  
Lucia Catani ◽  
Daria Sollazzo ◽  
Martina Barone ◽  
Margherita Perricone ◽  
...  
Keyword(s):  
T Cells ◽  
Immune Cells ◽  
Th17 Cells ◽  
Immune Cell ◽  
Opportunistic Infections ◽  
Fungal Infections ◽  
High Rate ◽  
Healthy Controls ◽  
Immune Cell Subsets

Abstract Introduction: Myelofibrosis (MF) is a clonal disorder associated mainly with JAK2V617F and MPL mutations. Recently, a new mutation in the gene encoding calreticulin (CALR) was discovered in the majority of JAK2/MPL negative patients. MF is burdened by a high rate of potentially life-threatening infections. The issue of recurrent and opportunistic infections is increased after the introduction in clinical practice of JAK inhibitors with immunosuppressive activity. However, the role of crucial immune cell subsets is still poorly characterized. Here, we investigated the phenotype/function of selected immune cells in MF. Specifically, we focused on circulating regulatory (Tregs) and IL-17-producing T cells (Th17 cells), monocytes and dendritic cells (DCs). Monocyte-derived DCs were also characterized. Methods: We characterized circulating Th17 cells, Tregs, monocytes and DCs of 17 untreated MF patients and 8 healthy controls (HC) by flow cytometry. Th17 cells were identified as CD4+ CD161+ CD196+ cells while Tregs were enumerated as CD4+ CD25high CD127low T cells. We also tested the in vitro suppressive activity of circulating CD4+ CD25+ Tregs with a mixed leukocyte reaction assay. Two subpopulations of circulating DCs, myeloid CD11c+ and plasmacytoid CD123+cells, were enumerated as well. In addition, after immunomagnetic selection, we tested both phenotype of circulating monocytes and their capacity to differentiate into CD14-derived immature and mature DCs, using a specific cytokines cocktail. JAK2V617F and MPL mutations were detected with RT-PCR while the presence of CALR mutations were tested with Exon 9 Next Generation Sequencing assay. Results: JAK2V617F (11 cases), MPL (3 cases), and CARL (3 cases) mutations were detected. We found that circulating CD4+CD25highCD127low Tregs were reduced in MF patients as compared with healthy controls (p=0.043), although their suppressive ability was maintained. We also found a lower number of circulating Th17 cells (p=0.0026) in MF patients. This finding was particularly evident in JAK2V617F+(p=0.008) and CARL+(p=0.03) patients. Despite their number was in the normal range, circulating monocytes from MF patients showed reduced expression of the CD86 co-stimulatory molecule. Moreover, as compared with the normal counterparts, immature monocytes-derived DCs from patients maintained low CD14 expression without upregulating the CD80 co-stimulatory molecule expression (p=0.0063). Interestingly, at variance with plasmacytoid DCs, a reduced number of circulating myeloid DCs was observed in MF patients as compared with that of HC (p=0.01). Conclusions: Here we demonstrated that specific crucial subsets of immune cells show quantitative and/or qualitative abnormalities in MF patients. These findings may be useful to better understand the increased susceptibility of these patients to infections, since Th17 cells play a role in bacterial and fungal infections while myeloid DCs regulate Th1 activity. Of note, DCs inhibition might result in increased propensity to infections and compromised immune response to cancer.In addition, since monocytes are DC precursors, alterations in their differentiation pathway may contribute to develop defective immune responses. Disclosures Martinelli: NOVARTIS: Consultancy, Speakers Bureau; BMS: Consultancy, Speakers Bureau; PFIZER: Consultancy; ARIAD: Consultancy.

Abstract 175: The Role of Axl in Accumulation of Immune Cells in Kidney and the Onset of Hypertension

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Sri Nagarjun Batchu ◽  
Angie Hughson ◽  
Janice Gerloff ◽  
Deborah J Fowell ◽  
Vyacheslav A Korshunov
Keyword(s):  
Blood Pressure ◽  
Immune Cells ◽  
Immune Cell ◽  
Kidney Injury ◽  
Wild Type ◽  
Protein Levels ◽  
Immune Cell Subsets ◽  
Early Increase ◽  
Salt Hypertension

Introduction: Gas6/Axl pathway contributes to elevation of blood pressure. Immune cells are implicated in initiation and maintenance of hypertension. In this study we aimed to investigate the role of Axl in immune cells on kidney injury and initiation of hypertension. Methods and Results: Deoxycorticosterone-acetate (DOCA; 75mg, 60days release) and salt hypertension was induced for 1wk or 6wks in four groups of Axl chimeras (n=4-5) that were generated by bone marrow (BM) transplant. Multi parameter flow cytometry was used to quantify five major immune cell subsets in digested kidneys from Axl chimeras. Systolic blood pressure (SBP) increased by 30mmHg in Axl+/+ →Axl+/+, Axl-/- →Axl-/- and Axl+/+ →Axl-/- mice after 1wk of DOCA-salt. However, chimeras that lack Axl in the BM cells (Axl-/- →Axl+/+) showed reduction in early increase in SBP (16+2mmHg). We observed a significant decrease in urine protein levels in Axl-/- →Axl+/+ (0.3+0.1μg/μl) compared to other Axl chimeras (∼0.7μg/μl) after 1wk of DOCA-salt. Kidney glomeruli areas were reduced in Axl-/- →Axl+/+ (4,143+229μm 2 ) compared to other Axl chimeras (∼6,000μm 2 ) after 6wks of DOCA-salt. Kidneys from Axl-/- →Axl-/- showed an increase in total leukocytes (8 vs. 4%), B cells (29 vs. 12%) and decrease in monocytes/macrophages (16 vs. 22%) and dendritic cells (5 vs. 10%) compared to Axl+/+ →Axl+/+. Moreover, Axl-/- →Axl+/+ showed further increase in leukocytes (17%), B (39%) and dendritic (13%) cells in kidneys compared to other Axl chimeras. In addition a small percentage of wild type T cells was increased in the kidneys from Axl-/- →Axl+/+ chimeras. Conclusions: These findings suggest that Axl expression in BM-derived cells is critical for kidney injury in DOCA-salt hypertension. Axl-dependent pathways regulate immune cell populations in the kidneys during initiation of hypertension. This study was supported by HL105623 grant (VAK)

The Liver Can Host Donor Hematopoiesis and Maintains a Strong Population of Innate Immune Cells That Contributes to Host Protection After Transplantation of Purified Hematopoietic Stem Cells.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3545-3545
Author(s):  
Pelu Tran ◽  
Antonia MS Mueller ◽  
Judith Shizuru
Keyword(s):  
Stem Cells ◽  
Innate Immunity ◽  
T Cells ◽  
Hematopoietic Stem Cells ◽  
Nk Cells ◽  
Immune Cells ◽  
Lymphoid Cells ◽  
Hematopoietic Stem ◽  
Host Protection

Abstract Abstract 3545 Poster Board III-482 Standing in the line of first defense, the liver is a critical immunocompetent organ. It is armed with lymphocytes, including T cells (TC), natural killer (NK) cells, NK T cells, and a variety of antigen-presenting cells (APC), such as dendritic cells and resident macrophages (Mph), called Kupffer cells. Because it is exposed to large amounts of toxins and antigens, both destructive and harmless, liver immunity must provide immunogenic and tolerogenic mechanisms. Moreover, as the organ of fetal blood production the liver can, if required, resume its hematopoietic function. Here, we studied the role of the liver as a hematopoietic and lymphatic organ after hematopoietic cell transplantation (HCT). Lethally irradiated BALB.K and BALB.B mice were given MHC-matched, FACS purified hematopoietic stem cells (HSC; cKit+Sca1+Thy1.1loLin-) from AKR/J and C57BL/6 donors, respectively, alone or supplemented with 10∧7 splenocytes (SP) for GVHD induction. Mononuclear cells (MNC) were Ficoll-separated from flushed livers 1 to 6 weeks (w) post transplant (pTX) and FACS analyzed. In recipients of TC-containing grafts, the liver was a major target organ of acute graft-vs-host disease (GVHD) with prominent donor lymphocyte expansion causing destruction of the hepatic portal morphology. Rare HSC-derived cells were observed in the livers. In contrast, mice given purified HSC showed no clinical or histological signs of GVHD, yet early pTX a high proportion of donor HSC-derived MNC was observed within the livers, comprising ∼75% of the MNC at 2w. Phenotype analysis revealed that these HSC-derived MNC were primarily NK cells (DX5+CD122+) or Mph (Mac1+F4/80+). In fact, amongst all nucleated cells, NK cells represented >10% and were mixed donor/host type. Interestingly, the Mph were all donor derived. This observation of over-representation by cells of innate immunity (including NK cells and Mph) in livers of recipients of HSC alone led us to hypothesize that these cells might exert protective functions against increased amounts of pathogens and toxins entering the circulation from irradiation-damaged intestines. Thus, to suppress donor Mph reconstitution pTX, silica was injected intraperitoneally on d-1, and every 3d thereafter. All recipients of HSC alone recovered rapidly after irradiation (d5-7), while at this time point recipients of HSC plus silica showed severe weight loss, hunched posture, ruffled fur, diarrhea, with <50% (7/15) survival. These survivors clinically stabilized around d12, suggesting that the intestines recovered from injury. To test if the presence of the HSC derived NK cells and APC could contribute to host protection from GVHD, a lethal dose of SP (10∧7) was injected simultaneously with HSC, or with a delay of 7d or 9d. All mice given SP on d0 died within 9d and 3/5 of those receiving SP on d7 died by d12. However, all mice given SP on d9 recovered fully and showed no signs of GVHD, despite the lymphopenic host environment that usually promotes homeostatic expansion of mature donor TC. In conclusion, the role of the liver as an immunologically active organ after ‘conventional’ HCT is often masked by donor TC expansion with subsequent GVHD. Here, we provide evidence that if grafts are devoid of mature lymphoid cells, innate immunity recovers rapidly, and in fact exceeds unmanipulated controls. Donor Mph may protect the host from pathogens and endotoxemia. Moreover, they may neutralize activated donor TC and thereby mediate tolerance between donor and host. Likewise, the elevated proportion of donor and host NK cells, which is lacking in GVHD affected mice, suggest another beneficial mechanism of protection, as NK cells have been reported to be capable of reducing GVHD. Immunohistochemical studies for a better quantitative assessment of resident immune cells in the liver pTX are underway. Disclosures: No relevant conflicts of interest to declare.

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