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Abstract: We report a first-in-human clinical trial using chimeric antigen receptor (CAR) T cells targeting CD37, an antigen highly expressed in B- and T-cell malignancies. Five patients with relapsed or refractory CD37+ lymphoid malignancies were enrolled and infused with autologous CAR-37 T cells. CAR-37 T cells expanded in the peripheral blood of all patients and, at peak, comprised >94% of the total lymphocytes in 4 of 5 patients. Tumor responses were observed in 4 of 5 patients with 3 complete responses, 1 mixed response, and 1 patient whose disease progressed rapidly and with relative loss of CD37 expression. Three patients experienced prolonged and severe pancytopenia, and in 2 of these patients, efforts to ablate CAR-37 T cells, which were engineered to coexpress truncated epidermal growth factor receptor, with cetuximab were unsuccessful. Hematopoiesis was restored in these 2 patients after allogeneic hematopoietic stem cell transplantation. No other severe, nonhematopoietic toxicities occurred. We investigated the mechanisms of profound pancytopenia and did not observe activation of CAR-37 T cells in response to hematopoietic stem cells in vitro or hematotoxicity in humanized models. Patients with pancytopenia had sustained high levels of interleukin-18 (IL-18) with low levels of IL-18 binding protein in their peripheral blood. IL-18 levels were significantly higher in CAR-37-treated patients than in both cytopenic and noncytopenic cohorts of CAR-19-treated patients. In conclusion, CAR-37 T cells exhibited antitumor activity, with significant CAR expansion and cytokine production. CAR-37 T cells may be an effective therapy in hematologic malignancies as a bridge to hematopoietic stem cell transplant. This trial was registered at www.ClinicalTrials.gov as #NCT04136275., (© 2024 American Society of Hematology. Published by Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.)

The diagnosis of Sézary syndrome (SS) relies on the identification of blood Sézary cells (SC) by different markers via flow cytometry. Treatment of SS is challenging since its pathogenesis is characterized by cell death resistance rather than hyperproliferation. In this study, we establish an integrated approach that considers both the expression of SC markers and sensitivity to cell death both spontaneously and upon in vitro treatment. Peripheral blood mononuclear cells were isolated from 20 SS patients and analysed for the SC markers CD7 and CD26 loss as well as CD158k and PD1 gain. The cells were then treated with different established and experimental therapies in vitro and cell death was measured. Spontaneous and therapeutically induced cell death were measured and correlated to cellular marker profiles. In the marker-positive cells, spontaneous cell death sensitivity was reduced. Different treatments in vitro managed to specifically induce cell death in the putative CTCL cell populations. Interestingly, a repeated analysis after 3 months of treatment revealed the CTCL cell death sensitivity to be restored by therapy. We propose this novel integrated approach comprising the evaluation of SC marker expression and analysis of cell death sensitivity upon treatment that can also enable a better therapy stratification., (© 2024 The Author(s). Experimental Dermatology published by John Wiley & Sons Ltd.)

Abstract: Adult T-cell leukemia/lymphoma (ATL) is a poor prognosis hematological malignancy originating from human T-cell leukemia virus 1 (HTLV-1)-infected CD4+ T cells. Flow cytometric plots of CADM1 and CD7 in CD4+ T cells are useful for separating HTLV-1-uninfected T cells and ATL cells. They are indicators of clonal evolution of HTLV-1-infected cells and disease progression of asymptomatic carriers or indolent ATL. However, the impacts of the plots on the clinical course or prognosis of ATL, especially in aggressive ATL, remain unclear. We focused on the N fraction (CD4+ CADM1+ CD7-) reflecting ATL cells and analyzed the flow cytometric profiles and clinical course of 497 samples from 92 HTLV-1-infected patients who were mainly aggressive ATL. The parameters based on N fractions showed significant correlations with known indicators of ATL disease status (soluble interleukin-2 receptor, lactate dehydrogenase, abnormal lymphocytes, etc.) and sensitively reflected the treatment response of aggressive ATL. The parameters based on N fractions significantly stratified the prognosis of aggressive ATL at 4 different time points: before treatment, after 1 course of chemotherapy, at the best response after chemotherapy, and before allogeneic hematopoietic cell transplantation. Even after mogamulizumab administration, which shows potent effects for peripheral blood lesions, the N fraction was still a useful indicator for prognostic estimation. In summary, this report shows that CADM1 vs CD7 plots in CD4+ T cells are useful indicators of the clinical course and prognosis of aggressive ATL. Therefore, this CADM1 and CD7 profile is suggested to be a useful prognostic indicator consistently from HTLV-1 carriers to aggressive ATL., (© 2024 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Targeted therapy development for acute myeloid leukaemia (AML) requires an understanding of specific expression profiles. We collected flow cytometry data on 901 AML patients and recorded aberrant CD7 expression on leukaemic blasts. 263 (29.2%) had blasts positive for CD7. CD7+ AML was more likely to be adverse risk (64.6% vs. 55.6%, p = 0.0074) and less likely to be favourable risk (15.2% vs. 24.1%, p = 0.0074) by European LeukemiaNet 2022 criteria. Overall survival was inferior (11.9 [95% CI, 9.7-15.9] vs. 19.0 months [95% CI, 16.1-23.0], p = 0.0174). At relapse, 30.4% lost and 19.0% gained CD7, suggesting moderate instability over time., (© 2024 British Society for Haematology and John Wiley & Sons Ltd.)

Objectives: Cytotoxic T cells and natural killer (NK) cells are central effector cells in cancer and infections. Their effector response is regulated by activating and inhibitory receptors. The regulation of these cells in systemic autoimmune diseases such as systemic sclerosis (SSc) is less defined., Methods: We conducted ex vivo analysis of affected skin and blood samples from 4 SSc patient cohorts (a total of 165 SSc vs 80 healthy individuals) using single-cell transcriptomics, flow cytometry and multiplex immunofluorescence staining. We further analysed the effects of costimulatory modulation in functional assays, and in a severely affected SSc patient who was treated on compassionate use with a novel anti-CD3/CD7 immunotoxin treatment., Results: Here, we show that SSc-affected skin contains elevated numbers of proliferating T cells, cytotoxic T cells and NK cells. These cells selectively express the costimulatory molecule CD7 in association with cytotoxic, proinflammatory and profibrotic genes, especially in recent-onset and severe disease. We demonstrate that CD7 regulates the cytolytic activity of T cells and NK cells and that selective depletion of CD7 + cells prevents cytotoxic cell-induced fibroblast contraction and inhibits their profibrotic phenotype. Finally, anti-CD3/CD7 directed depletive treatment eliminated CD7 + skin cells and stabilised disease manifestations in a severely affected SSc patient., Conclusion: Together, the findings imply costimulatory molecules as key regulators of cytotoxicity-driven pathology in systemic autoimmune disease, yielding CD7 as a novel target for selective depletion of pathogenic cells., Competing Interests: Competing interests: YvO is employee of Philikos and owns stocks in Philikos. The remaining authors have no conflicts of interest to report., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The survival rate for patients with relapsed and refractory acute myeloid leukaemia (R/R-AML) remains poor, and treatment is challenging. Chimeric antigen receptor T cells (CAR-T cells) have been widely used for haematologic malignancies. Current CAR-T therapies for acute myeloid leukaemia mostly target myeloid-lineage antigens, such as CD123 and CD33, which may be associated with potential haematopoietic toxicity. As a lineage-specific receptor, CD7 is expressed in acute myeloid leukaemia cells and T cells but is not expressed in myeloid cells. Therefore, the use of CD7 CAR-T cells for R/R-AML needs to be further explored., Methods: In this report, immunohistochemistry and flow cytometry were used to analyse CD7 expression in clinical samples from R/R-AML patients and healthy donors (HDs). We designed naturally selected CD7 CAR-T cells to analyse various functions and in vitro antileukaemic efficacy based on flow cytometry, and xenograft models were used to validate in vivo tumour dynamics., Results: We calculated the percentage of cells with CD7 expression in R/R-AML patients with minimal residual disease (MRD) (5/16, 31.25%) from our institution and assessed CD7 expression in myeloid and lymphoid lineage cells of R/R-AML patients, concluding that CD7 is expressed in T cells but not in myeloid cells. Subsequently, we designed and constructed naturally selected CD7 CAR-T cells (CD7 CAR). We did not perform CD7 antigen knockdown on CD7 CAR-T cells because CD7 molecule expression is naturally eliminated at Day 12 post transduction. We then evaluated the ability to target and kill CD7 + acute myeloid leukaemia cells in vitro and in vivo. Naturally selected CD7 CAR-T cells efficiently killed CD7 + acute myeloid leukaemia cells and CD7 + primary blasts of R/R-AML patients in vitro and significantly inhibited leukaemia cell growth in a xenograft mouse model., Conclusion: Naturally selected CD7 CAR-T cells represent an effective treatment strategy for relapsed and refractory acute myeloid leukaemia patients in preclinical studies., (© 2022. The Author(s).)

Targeting T cell malignancies using chimeric antigen receptor (CAR) T cells is hindered by 'T v T' fratricide against shared antigens such as CD3 and CD7. Base editing offers the possibility of seamless disruption of gene expression of problematic antigens through creation of stop codons or elimination of splice sites. We describe the generation of fratricide-resistant T cells by orderly removal of TCR/CD3 and CD7 ahead of lentiviral-mediated expression of CARs specific for CD3 or CD7. Molecular interrogation of base-edited cells confirmed elimination of chromosomal translocations detected in conventional Cas9 treated cells. Interestingly, 3CAR/7CAR co-culture resulted in 'self-enrichment' yielding populations 99.6% TCR-/CD3-/CD7-. 3CAR or 7CAR cells were able to exert specific cytotoxicity against leukaemia lines with defined CD3 and/or CD7 expression as well as primary T-ALL cells. Co-cultured 3CAR/7CAR cells exhibited highest cytotoxicity against CD3 + CD7 + T-ALL targets in vitro and an in vivo human:murine chimeric model. While APOBEC editors can reportedly exhibit guide-independent deamination of both DNA and RNA, we found no problematic 'off-target' activity or promiscuous base conversion affecting CAR antigen-specific binding regions, which may otherwise redirect T cell specificity. Combinational infusion of fratricide-resistant anti-T CAR T cells may enable enhanced molecular remission ahead of allo-HSCT for T cell malignancies., (© 2021. The Author(s).)

Although defined as a lymphoid surface marker, CD7 is aberrantly expressed on a subtype of acute myeloid leukemia cells and appears to be associated with an inferior response to chemotherapy. Allogeneic hematopoietic cell transplantation (allo-HCT) is a potentially curative modality but no data has been reported in CD7-positive AML patients. We performed a retrospective analysis involving 141 AML patients who underwent allo-HCT in first morphological complete remission (CR1). The results showed that CD7-positive AML patients had a poor 2-year overall survival (64.5% vs 82.0%, P = 0.040), relapse-free survival (RFS) (56.5% vs 79.4%, P = 0.005), and higher cumulative incidence of relapse (27.0% vs 9.7%, P = 0.003) post-HCT. In addition, expression of CD7 was related to RAS and RUNX1 mutation, and high residual disease level pre-HCT. Multivariate analyses showed CD7 expression at diagnosis was an independent risk factor for RFS (P = 0.016, HR = 0.418) and relapse (P = 0.014, HR = 0.307). We concluded that for AML patients in CR1, CD7 is a negative predictor for allo-transplant outcomes., (© 2021. Japanese Society of Hematology.)

Refractory T cell acute leukaemias that no longer respond to treatment would benefit from new modalities that target T cell-specific surface proteins. T cell associated surface proteins (the surfaceome) offer possible therapy targets to reduce tumour burden but also target the leukaemia-initiating cells from which tumours recur. Recent studies of the T cell leukaemia surfaceome confirmed that CD7 is highly expressed in overt disease. We have used an anti-CD7 antibody drug conjugate (ADC) to show that the binding of antibody to surface CD7 protein results in rapid internalization of the antigen together with the ADC. As a consequence, cell killing was observed via induction of apoptosis and was dependent on cell surface CD7. The in vitro cytotoxic activity (EC 50 ) of the anti-CD7 ADC on T cell acute leukaemia (T-ALL) cells Jurkat and KOPT-K1 was found to be in the range of 5-8 ng/mL. In a pre-clinical xenograft model of human tumour growth expressing CD7 antigen, growth was curtailed by a single dose of ADC. The data indicate that CD7 targeting ADCs may be developed into an important second stage therapy for T cell acute leukaemia, for refractory CD7-positive leukaemias and for subsets of acute myeloid leukaemia (AML) expressing CD7., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Effective systemic treatments for relapsed or refractory T-cell acute lymphoblastic leukemia (T-ALL) are limited. Recent clinical application of chimeric antigen receptor (CAR) immunotherapy has demonstrated successful control of B-cell malignancies by CAR-T cells; however, designing CARs for T-ALL remains a challenge. CD7 overexpression in T-cell malignancies may be an attractive target for immunotherapy in T-ALL. This study aimed to describe the safe and effective use of autologous CD7-CAR T cells (4SCAR7) for the treatment of T-ALL with induction failure in an 11-year-old patient. Based on The Chinese Children's Cancer Group-ALL (CCCG-ALL) study protocol, minimal residual disease (MRD) by flow cytometry (FC) analysis was detected on days 19 and 46 of remission induction. At the end of remission-induction chemotherapy, the patient achieved morphologic complete remission, though with MRD 16.13% and RT-PCR of KMT2A-MLLT1 fusion positive, which indicated induction failure. The cerebrospinal fluid (CSF) was negative for blasts at diagnosed. CAR-T therapy and allogeneic transplant were recommended as the next treatment options. CD3 + lymphocytes were collected from the patient 18 days after the high-dose MTX chemotherapy through leukapheresis. The 4SCAR7 CD7-targeting CAR-T cells were generated thereafter. The patient received lymphodepleting chemotherapy prior to 4SCAR7 infusion. Oral administration of itraconazole and sulfamethoxazole was performed from day 0 after CAR-T cell infusion. The patient did not have hypotension, hypoxia, or serious biochemical change or abnormality, but had fever on day 9. Although grade 1 cytokine-release syndrome (CRS) was diagnosed, it was successfully treated with ibuprofen. Anti-CD7 CAR transgene copy numbers in peripheral blood were determined by qPCR, which showed effective expansion initially, then dropped quickly, and persisted at a low level. Although experienced cytopenia from days 14 to 21, the patient achieved remission on day 17. After complete remission, the patient received hematopoietic stem cell transplantation (HSCT) and has recovered well to thisdate. Overall, this report suggested that 4SCAR7 could be a safe and effective strategy for the treatment of pediatric patients with high-risk T-cell malignancies., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background: Myelodysplastic syndromes (MDS) can present a challenge for clinicians. Multicolor flow cytometry (MFC) can aid in establishing a diagnosis. The aim of this study was to determine the optimal MFC approach for MDS., Methods: The study included 102 MDS (39 low-grade MDS), 83 cytopenic patients without myeloid neoplastic disorders (control group), and 35 healthy donors. Bone marrow was analyzed using a six-color MFC. Analysis was conducted according to the "Ogata score," "Wells score," and the integrated flow cytometry (iFC) score., Results: The respective sensitivity and specificity values were 77.5% and 90.4% for the Ogata score, 79.4% and 81.9% for the Wells score, and 87.3% and 87.6% for the iFC score. Specificity was not 100% due to deviations of MFC parameters in the control group. Patients with paroxysmal nocturnal hemoglobinuria (PNH) had higher levels of CD34 + CD7 + myeloid cells than donors. Aplastic anemia and PNH were characterized by a high proportion of CD56 + cells among CD34 + precursors and neutrophils. The proportion of MDS-related features increased with the progression of MDS. The highest number of CD34 + blasts was found in MDS with excess blasts. MDS with isolated del(5q) was characterized by a high proportion of CD34 + CD7 + cells and low granularity of neutrophils. In 39 low-grade MDS, the sensitivities were 53.8%, 61.5%, and 71.8% for Ogata score, Wells score, and iFC, respectively., Conclusion: The results support iFC as a useful diagnostic tool in MDS., (© 2020 International Clinical Cytometry Society.)

Background: CD34 antigen is expressed by early hematopoietic progenitor cells and acute leukemia cells. Its expression is associated with good prognosis in acute myeloid leukemia. Literature is sparse on its prognostic significance in B- acute lymphoblastic leukemia (B-ALL) especially from India. Hence the present study was undertaken to analyse the frequency of CD34 expression in B-ALL in Indian patients and determine its prognostic significance by associating with other prognostic markers and aberrant antigen expression., Methods: Seventy-five B-ALL patients diagnosed by flow cytometry over a period of 3½ year were studied. Correlation of CD34 expression was studied with gender, age, total leucocyte count (TLC), French-American-British (FAB) morphological type, immuno-phenotypic markers, cytogenetics and minimal residual disease. Differences between groups were evaluated using Student's T-test for quantitative data and Chi-square test/Fishers exact T-test for qualitative variables. P value.

Objective: To analysis the expression of CD7 in NK/T-cell lymphoma as well as study the correlations between CD7 and clinical survival and prognosis. Methods: The clinical and pathological indicators of 112 NKTCL patients who were admitted to or consulted at the First Affiliated Hospital of Zhengzhou University between May 2008 and December 2019 were analyzed retrospectively. The CD7 expression in the tumor tissues was detected using immunohistochemistry staining, and the influence of CD7 expression on the survival and prognosis in the patients was analyzed. Results: The CD7 expression rate was 84.82% in 112 NKTCL patients, and its expression was not influenced by sex, age, and the primary site. An analysis of the complete clinical data of 72 patients showed that the CD7 expression was significantly correlated with the PINK score, tumor metastasis, and peripheral blood EBV-DNA level. However, the Ann Arbor stage, bone marrow involvement, B symptoms, IPI/aaIPI score, Ki-67, EBER, TIA-1, Granzyme B, LDH, and β(2)-MG were not associated with the CD7 expression. The 1-year, 3-year, and 5-year overall survival (OS) rates of the 72 patients were 81.2%, 61.8%, and 58.8%, respectively, and the progression-free survival (PFS) rates were 53.5%, 29.4%, and 24.0%, respectively. The median overall survival (median-OS, mOS) was 81 mon, and the median progression-free survival (median-PFS, mPFS) was 14 mon. The 3-year OS rates in the CD7-positive group and the CD7-negative group were 58.1% and 83.9%, respectively, ( P >0.05) . The 3-year PFS rates were 21.7% and 51.9%, respectively ( P <0.05) . The univariate analysis showed that age, primary tumor site, Ann Arbor stage, IPI/aaIPI score, PINK score, LDH, β(2)-microglobulin, EBV-DNA, Ki-67, and CD7 influenced patient prognosis. The multivariate analysis showed that Ann Arbor stage and CD7 were independent prognostic factors for PFS, while PINK score and Ki-67 were independent prognostic factors for OS. Conclusions: The expression rate of CD7 in NKTCL was high and was closely related to poor patient prognosis. The patients with high levels of EBV-DNA, metastatic disease, or high PINK score were more likely to express CD7.

Introduction: FLT3 internal tandem duplication (ITD) mutations are found in around 25% of all acute myeloid leukaemia (AML) cases and is associated with shorter disease-free and overall survival. Previous reports have shown that FLT3-ITD induces a specific phenotype in leukemic blasts, which is characterized by high levels of CD33 and CD123, and that expression of CD33 and CD123 is directly influenced by the DNA FLT3-ITD/wild-type FLT3 allelic ratio (AR)., Methods: A total of 42 FLT3-ITD and 104 FLT3-ITD-negative AML patients were analysed. Immunophenotyping data were used to calculate antigen expression levels as the ratio between the geometric mean fluorescence intensities (MFIs) of leukemic blasts and MFIs of negative lymphocyte populations. FLT3-ITD-DNA and RNA analysis was performed, under the same conditions, by capillary electrophoresis., Results: Compared with the control group, the FLT3-ITD cohort presented significantly higher CD7, CD33 and CD123 levels. In order to assess the impact of FLT3-ITD abundance on antigen expression, the patients were grouped for each parameter into two cohorts using the following threshold values: (a) 0.5 for the AR, according to current AML guidelines; (b) 0.7 for the FLT3-ITD/FLT3-WT mRNA ratio (RR); and (c) 1.3 for the FLT3-ITD RR/AR ratio. We found higher values of CD33 for RR/AR ≥1.3, and no other statistical differences between CD7, CD33 and CD123 levels of the other FLT3-ITD groups. In terms of correlations between MFI values and FLT3-ITD parameters, we only observed a moderate interdependence between CD33 MFI and the RR/AR ratio, and a weak negative correlation between CD123 MFI and AR., Conclusion: FLT3-ITD mutations induce a specific antigen profile in AML blasts, and our data do not onfirm previous reports of FLT3-ITD AR influencing both CD33 and CD123 expression., (© 2020 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)

Natural killer (NK) cells comprise of ∼70% of the immune cell population in the maternal decidua and ∼15% of the mononuclear cells in the peripheral blood. The decidual NK cells capable of producing high levels of cytokines are functionally distinct from the peripheral NK cells that exhibit high cytotoxicity. The numbers of peripheral NK cells and their cytotoxicity potential have been correlated with pregnancy outcome. In the same context, glycodelin, an immunomodulatory protein, has been recognized to be essential for the establishment and maintenance of pregnancy, and its' reduced levels are associated with recurrent spontaneous abortions. We investigated the effect of glycodelin on the peripheral NK cells. Our results reveal that glycodelin suppresses the cytotoxicity of peripheral NK cells via downregulating perforin, granzyme B and IFNγ. Glycodelin also induces caspase-dependent death in only activated peripheral NK cells, the effect suggested to be mediated by glycodelin upon engaging with the CD7 cell surface receptor. Thus, during pregnancy, glycodelin modulates the function and the number of cytotoxic NK cells that pose a deleterious effect on the fetus, a semi-allograft. This study provides insights into the mechanism of the regulatory effect of glycodelin on NK cells and could possibly be exploited for the management of miscarriages., Competing Interests: Declaration of Competing Interest Authors do not have any conflict of interest, (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Aberrant phenotypes in acute leukemia have been reported with varying frequencies in independent studies and their association with prognostic factors is still a matter of debate., Aim: This study aims to identify the frequency of aberrant immunophenotypes in de novo acute myeloid leukemia (AML) and to evaluate their association with initial clinical and hematological features., Materials and Methods: A total of 181 patients of de novo AML were included during the time (July 2010-June 2012). The immunophenotype of all cases of AML was studied by using flow cytometry., Results: Aberrant lymphoid antigen expression was seen in 43.1% cases. Most frequent aberrant lymphoid antigen was CD7, seen in 26.5% cases. All French-American-British (FAB) subtypes except AML-M3 expressed aberrant lymphoid antigens. The expression was most common in AML-M4 in the current study. CD34 expression in AMLs was significantly associated with the expression of aberrant lymphoid antigens. Lymphoid antigen expression in adult AML was significantly associated with higher white blood cell (WBC) count (>50,000/mm 3 ) and higher number of peripheral blasts (>70%)., Conclusion: In summary, CD7 is the most common aberrant lymphoid antigen expressed in AML. FAB subtype AML-M3 is usually not associated with aberrant lymphoid antigen expression. AML cases with CD34 positivity are more likely to express aberrant lymphoid markers. The current study also supports that aberrant lymphoid antigen expression in adult AML is associated with adverse presenting hematological features (WBC count >50,000/mm 3 , peripheral blasts >70%). Pediatric Ly + AML cases are not associated with adverse presenting clinical and biological features., Competing Interests: None

Background: T cell immunophenotypes in patients with hemophagocytic lymphohistiocytosis (HLH) have been described. Downregulation of CD5 or CD7 on T cells has been reported in patients with Epstein-Barr virus (EBV)-positive HLH. As the utility of T cell immunophenotypes as an adjunctive diagnostic or a prognostic marker for HLH has not been evaluated, we analyzed T cell immunophenotypes in HLH patients for this purpose., Methods: We classified 45 HLH patients into three subgroups: EBV-positive HLH (N=27), EBV-negative secondary HLH (N=15), and familial HLH (N=3). We retrospectively characterized downregulation patterns of CD5 or CD7 on activated T cells, using flow cytometry. Overall survival was estimated using Kaplan-Meier curves and compared using the log-rank test., Results: An aberrant immunophenotype, including CD5 and/or CD7 downregulation on T cells, was observed in 55.6% (15/27) of the EBV-positive HLH patients and 100% of the familial HLH (3/3). Only one (1/15, 6.7%) patient with EBV-negative secondary HLH showed an aberrant loss of CD7 antigen on CD8 + T cells. The presence of an aberrant T cell immunophenotype was not related to overall survival in EBV-positive HLH and EBV-negative secondary HLH patients., Conclusions: An aberrant T cell immunophenotype may assist in discriminating EBV-negative secondary HLH and EBV-positive HLH. However, it may not be useful as a prognostic marker., Competing Interests: No potential conflicts of interest relevant to this article were reported., (© The Korean Society for Laboratory Medicine.)

Scaling up blood cell production from hPSCs is critical to advancing hPSC technologies for blood transfusion, immunotherapy, and transplantation. Here we explored the potential of the HSC agonist pyrimido-indole derivative UM171, to expand hematopoietic progenitors (HPs) derived from hPSCs in chemically defined conditions. We revealed that culture of hPSC-HPs in HSC expansion conditions (SFEM with added TPO, SCF, FLT3L, IL3 and IL6) in the presence of UM171 predominantly expanded HPs with a unique CD34 + CD41a lo CD45 + phenotype that were enriched in granulocytic progenitors (G-CFCs). In contrast, in lymphoid cultures on OP9-DLL4, in the presence of SCF, FLT3L, and IL7, UM171 selectively expanded CD34 + CD45 + CD7 + lymphoid progenitors with NK cell potential, and increased NK cell output up to 10-fold. These studies should improve our understanding of the effect of UM171 on de novo generated HPs, and facilitate development of protocols for robust granulocyte and lymphoid cell production from hPSCs, for adoptive immunotherapies.

The CD7 antigen is a member of the immunoglobulin superfamily that expresses on the surface of all thymocytes, a majority of mature T cells, and also natural killer cells. Interestingly, under physiological and different pathological conditions, the loss of CD7 antigen occurred in the subset of CD4 + memory T cells. Various functions have been proposed for CD7, including its role in the activation and intercellular adhesiveness of T cells. Several studies indicate that the number of CD4 + CD7 - T cells increases in diseases such as chronic inflammation and T-cell malignancies, these being skin inflammatory lesions. Therefore, this can be useful for the diagnosis of cancer cells, especially with reference to blood origin, treatment monitoring, and establishment of new therapies. Therefore, a comprehensive review could be useful to increase our knowledge about the clinical importance of these cells in human disease., (© 2018 Wiley Periodicals, Inc.)

HIV-1 causes the loss of CD4 + T cells via depletion or impairment of their production. The latter involves infection of thymocytes, but the involvement of hematopoietic CD34 + cells remains unclear even though HIV-positive patients frequently manifest myelosuppression. In order to have a closer look at the impact of HIV-1 on T-lineage differentiation, this study utilized the OP9-DL1 coculture system, which supports in vitro T-lineage differentiation of human hematopoietic stem/progenitor cells. In the newly developed in vitro OP9-DL1/HIV-1 model, cord-derived CD34 + cells were infected with CXCR4-tropic HIV-1 NL4-3 and cocultured. The HIV-infected cocultures exhibited reduced CD4 + T-cell growth at weeks 3-5 post infection compared to autologous uninfected cocultures. Further assays and analyses revealed that CD34 + CD7 + CXCR4 + cells can be quickly depleted as early as 1 week after infection of the subset, and this was accompanied by the emergence of rare CD34 + CD7 + CD4 + cells. A subsequent theoretical model analysis suggested potential influence of HIV-1 on the differentiation rate or death rate of lymphoid progenitor cells. These results indicate that CXCR4-tropic HIV-1 strains may impact the dynamics of CD34 + CD7 + lymphoid progenitor cell pools, presumably leading to impaired T-cell production potential.

Chimeric antigen receptor (CAR) T cell therapy for the treatment of acute myeloid leukemia (AML) has the risk of toxicity to normal myeloid cells. CD7 is expressed by the leukemic blasts and malignant progenitor cells of approximately 30% of AML patients but is absent on normal myeloid and erythroid cells. Since CD7 expression by malignant blasts is also linked with chemoresistance and poor outcomes, targeting this antigen may be beneficial for this subset of AML patients. Here, we show that expression of a CD7-directed CAR in CD7 gene-edited (CD7 KO ) T cells effectively eliminates CD7 + AML cell lines, primary CD7 + AML, and colony-forming cells but spares myeloid and erythroid progenitor cells and their progeny. In a xenograft model, CD7 CAR T cells protect mice against systemic leukemia, prolonging survival. Our results support the feasibility of using CD7 KO CD7 CAR T cells for the non-myeloablative treatment of CD7 + AML., (Copyright © 2018 The American Society of Gene and Cell Therapy. Published by Elsevier Inc. All rights reserved.)

Objective: To improve monitoring of myeloid neoplasms by flow cytometry-based minimal residual disease (MRD) analysis, we analyzed the significance of leukemia-associated immunophenotype (LAIP) markers in 44 patients., Methods: In a pilot study cohort, peripheral blood or bone marrow samples from 13 patients with myeloid neoplasms and one case of B lymphoblastic leukemia in complete hematologic remission after allogeneic bone marrow or stem cell transplantation were subjected to selection for leukemia-specific phenotypes by fluorescence-activated cell sorting using individual marker combinations, followed by PCR-based chimerism analysis., Results: The feasibility of this method could be demonstrated, with selection being successful in 12 cases, including two cases where mixed chimerism was found exclusively in sorted cells. Interestingly, four specimens displayed full donor chimerism in cells expressing the presumably aberrant combination CD34 + /CD7 + . Further analyses, including assessment of an independent cohort of 25 patients not affected by neoplastic bone marrow infiltration, revealed that normal myeloid precursors usually include a population coexpressing CD34, CD13, CD33, and CD7., Conclusion: We conclude that the combination CD34 + /CD7 + might not be suitable as an LAIP for MRD diagnostics and that a subset of normal myeloid precursors in the bone marrow expresses CD7., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Aims: To create clinically relevant normative flow cytometry data for understudied benign lymph nodes and characterise outliers., Methods: Clinical, histological and flow cytometry data were collected and distributions summarised for 380 benign lymph node excisional biopsies. Outliers for kappa:lambda light chain ratio, CD10:CD19 coexpression, CD5:CD19 coexpression, CD4:CD8 ratios and CD7 loss were summarised for histological pattern, concomitant diseases and follow-up course., Results: We generated the largest data set of benign lymph node immunophenotypes by an order of magnitude. B and T cell antigen outliers often had background immunosuppression or inflammatory disease but did not subsequently develop lymphoma., Conclusions: Diagnostic immunophenotyping data from benign lymph nodes provide normative ranges for clinical use. Outliers raising suspicion for B or T cell lymphoma are not infrequent (26% of benign lymph nodes). Caution is indicated when interpreting outliers in the absence of excisional biopsy or clinical history, particularly in patients with concomitant immunosuppression or inflammatory disease., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Understanding the pathways and regulation of human haematopoiesis, in particular, lymphopoiesis, is vital to manipulation of these processes for therapeutic purposes. However, although haematopoiesis has been extensively characterised in mice, translation of these findings to human biology remains rudimentary. Here, we describe the isolation of three progenitor subsets from human foetal bone marrow that represent differential stages of commitment to the natural killer (NK) cell lineage based on IL-15 responsiveness. We identify CD7 as a marker of IL-15 responsive progenitors in human bone marrow and find that this expression is maintained throughout commitment and maturation. Within the CD7⁺ fraction, we focussed on the lineage potential of three subsets based on CD127 and CD117 expression and observed restricted lymphoid and biased NK cell potential amongst subsets. We further demonstrate the presence of subsets similar in both phenotype and function in umbilical cord blood and the bone marrow of humanised mice, validating these as appropriate sources of progenitors for the investigation of human haematopoiesis. Overall, we describe several stages in the process of lymphopoiesis that will form the basis of investigating the regulators of this process in humans., Competing Interests: The authors declare no conflict of interest.

We previously reported that the T-cell receptor (TCR) repertoire of human T-cell lymphotropic virus type 1 (HTLV-1) Tax 301-309 -specific CD8 + cytotoxic T cells (Tax 301-309 -CTLs) was highly restricted and a particular amino acid sequence motif, the PDR motif, was conserved among HLA-A*24:02-positive (HLA-A*24:02 + ) adult T-cell leukemia/lymphoma (ATL) patients who had undergone allogeneic hematopoietic cell transplantation (allo-HSCT). Furthermore, we found that donor-derived PDR + CTLs selectively expanded in ATL long-term HSCT survivors with strong CTL activity against HTLV-1. On the other hand, the TCR repertoires in Tax 301-309 -CTLs of asymptomatic HTLV-1 carriers (ACs) remain unclear. In this study, we directly identified the DNA sequence of complementarity-determining region 3 (CDR3) of the TCR-β chain of Tax 301-309 -CTLs at the single-cell level and compared not only the TCR repertoires but also the frequencies and phenotypes of Tax 301-309 -CTLs between ACs and ATL patients. We did not observe any essential difference in the frequencies of Tax 301-309 -CTLs between ACs and ATL patients. In the single-cell TCR repertoire analysis of Tax 301-309 -CTLs, 1,458 Tax 301-309 -CTLs and 140 clones were identified in this cohort. Tax 301-309 -CTLs showed highly restricted TCR repertoires with a strongly biased usage of BV7, and PDR, the unique motif in TCR-β CDR3, was exclusively observed in all ACs and ATL patients. However, there was no correlation between PDR + CTL frequencies and HTLV-1 proviral load (PVL). In conclusion, we have identified, for the first time, a unique amino acid sequence, PDR, as a public TCR-CDR3 motif against Tax in HLA-A*24:02 + HTLV-1-infected individuals. Further investigations are warranted to elucidate the role of the PDR + CTL response in the progression from carrier state to ATL. IMPORTANCE ATL is an aggressive T-cell malignancy caused by HTLV-1 infection. The HTLV-1 regulatory protein Tax aggressively promotes the proliferation of HTLV-1-infected lymphocytes and is also a major target antigen for CD8 + CTLs. In our previous evaluation of Tax 301-309 -CTLs, we found that a unique amino acid sequence motif, PDR, in CDR3 of the TCR-β chain of Tax 301-309 -CTLs was conserved among ATL patients after allo-HSCT. Furthermore, the PDR + Tax 301-309 -CTL clones selectively expanded and showed strong cytotoxic activities against HTLV-1. On the other hand, it remains unclear how Tax 301-309 -CTL repertoire exists in ACs. In this study, we comprehensively compared Tax-specific TCR repertoires at the single-cell level between ACs and ATL patients. Tax 301-309 -CTLs showed highly restricted TCR repertoires with a strongly biased usage of BV7, and PDR, the unique motif in TCR-β CDR3, was conserved in all ACs and ATL patients, regardless of clinical subtype in HTLV-1 infection., (Copyright © 2017 American Society for Microbiology.)

Immunophenotypic changes and lineage switch between diagnosis and relapse in acute lymphoblastic leukemia are uncommon and accompanied by poor outcomes. In this report, a 12-year-old boy with diagnosis of pre-B ALL with an aberrant expression of CD 7 is described. Patient was treated with the ALL-BFM 2000 protocol and suffered an episode of relapse with a lineage switch from pre-B ALL to T cell ALL. This report concludes that presence of aberrant expression of CD7 at diagnosis of pre-B ALL can have prognostic value of lineage switch to T cell ALL at relapse.

Although numerous recent publications have demonstrated interest in multiparameter flow cytometry in the investigation of myelodysplastic disorders, it is perceived by many laboratory hematologists as difficult and expensive, requiring a high level of expertise. We report a multicentric open real-life study aimed at evaluating the added value of the technically simple flow cytometry score described by the Ogata group for the diagnosis of myelodysplastic syndromes. A total of 652 patients were recruited prospectively in four different centers: 346 myelodysplastic syndromes, 53 myelodysplastic/myeloproliferative neoplasms, and 253 controls. The Ogata score was assessed using CD45 and CD34 staining, with the addition of CD10 and CD19. Moreover, labeling of CD5, CD7 and CD56 for the evaluation of myeloid progenitors and monocytes was tested on a subset of 294 patients. On the whole series, the specificity of Ogata score reached 89%. Respective sensitivities were 54% for low-risk myelodysplastic syndromes, 68% and 84% for type 1 and type 2 refractory anemia with excess of blasts, and 72% for myelodysplastic/myeloproliferative neoplasms. CD5 expression was poorly informative. When adding CD56 or CD7 labeling to the Ogata score, sensitivity rose to 66% for low-risk myelodysplastic syndromes, to 89% for myelodysplastic/myeloproliferative neoplasms and to 97% for refractory anemia with excess of blasts. This large multicenter study confirms the feasibility of Ogata scoring in routine flow cytometry diagnosis but highlights its poor sensitivity in low-risk myelodysplastic syndromes. The addition of CD7 and CD56 in flow cytometry panels improves the sensitivity but more sophisticated panels would be more informative., (Copyright© Ferrata Storti Foundation.)

Immunophenotypic distinction between neoplastic and reactive T-cell clones can be challenging, as peripheral T-cell lymphomas (PTCLs) lack an immunophenotypic marker of clonality. Systematic screening of 10,510 cases analyzed by immunophenotyping at our institution between 2006 and 2012 resulted in 49 cases with aberrant T-cell populations of unclear significance. Review of patient charts allowed us to assign these cases to three categories. In 21 cases, PTCL could later be confirmed by complementary diagnostics (PTCL group). In 20 cases, follow-up confirmed the reactive nature of the aberrant T-cells (non-PTCL group). Eight cases remained of unclear significance. Neither the population size nor the number of aberrant markers differed significantly between the PTCL and non-PTCL groups. Only loss of CD7 was found significantly more often in patients with PTCL than in patients with non-PTCL (p = 0.037). Our data show that aberrant T-cell populations need to be interpreted in the clinicopathological context, as reactive and neoplastic phenotypes largely overlap.

Thymopentin is a group of biologically active peptide secreted mainly by the epithelial cells of thymic cortex and medulla. Whether it promotes T cells production from human embryonic stem cells(hESCs) in vitro remains an elusive issue. In the present study, we develop a novel strategy that enhances T-cell lineage differentiation of hESCs in collagen matrix culture by sequential cytokine cocktails treatment combined with thymopentin stimulation. We observed that approximately 30.75% cells expressed CD34 on day 14 of the cultures and expressed the surface markers of erythroid, lymphoid and myeloid lineages. The results of colony assays and gene expressions by RT-PCR analysis also demonstrated that hematopoietic progenitor cells (HPCs) derived from hESCs were capable of multi-lineage differentiation. Further study revealed that culturing with thymopentin treatment, the CD34(+)CD45RA(+)CD7(+) cells sorted from HPCs expressed T-cell-related genes, IKAROS, DNTT, TCRγ and TCRβ, and T-cell surface markers, CD3, cytoplasmic CD3, CD5, CD27, TCRγδ, CD4 and CD8. The differentiated cells produced the cytokines including IFN-γ, IL-2 and TNF-α in response to stimulation, providing the evidence for T-cell function of these cells. In conclusion, thymopentin enhances T-cell lineage differentiation from hESCs in vitro by mimicking thymus peptide environment in vivo., (Copyright © 2015 Elsevier Inc. All rights reserved.)

FLT3 mutations are common in acute myeloid leukemia (AML), particularly in cases with normal karyotype. Internal tandem duplication (ITD) and also point mutations affecting aspartic acid 835 (D835) are reported. A previous study demonstrated aberrant expression of CD7 on blasts in de novo AML cases with FLT3/ITD mutations. Our study goals are to expand the evaluation of this association to a larger group of patients; to evaluate the association of aberrant CD7 expression in AMLs with D835 mutation, not previously done; to evaluate if aberrant CD7 expression may serve as a surrogate marker for predicting FLT3 mutational status; to evaluate if combined FLT3 with NPM1 mutational status has a better correlation with CD7 expression. The FLT3 mutational analysis was performed on DNA extracted from 149 previously diagnosed AML cases with cytogenetics and flow cytometry evaluation available. Of 149 patients, 28 were positive for FLT3; CD7 was positive in 13 of 20 ITD-positive cases, 5 of 6 D835-positive cases, and 1 of 2 ITD/D835-positive cases. The association of CD7 positivity and FLT3 positivity was found to be significant. However, CD7 expression has a low positive predictive value of 30% and a negative predictive value of 90%. Because of the low positive predictive value, CD7 expression cannot be used as a surrogate marker for FLT3 positivity; even though the negative predictive value is higher, some cases that are FLT3 positive may be missed if CD7 expression would be used for screening.

Objectives: Sézary syndrome (SS) is characterized by erythroderma, generalized lymphadenopathy, and the presence of circulating atypical lymphocytes, which are difficult to identify by morphologic data., Methods: We revised our series of 107 patients in an attempt to better define the phenotypic aberrancies in blood at diagnosis and the immunophenotypic stability over time detected by flow cytometry. Polymerase chain reaction assay was also used to study CD26/dipeptidyl peptidase IV (DPPIV) gene methylation., Results: The most common aberrancies were represented by the lack of CD26 (96/107) or CD38 (101/107) expression and the presence of a "dim" CD3, CD4, or CD2 population. There was a high variability in CD7 expression. In total, 31% of the patients had phenotypical heterogeneity in CD26 and CD7 expression at diagnosis. The phenotype was stable over time in 73 of 95 patients with available follow-up data, while 22 of 95 patients developed changes in CD26, CD7, or CD2 expression. CD4+CD26- SS showed hypermethylation of the CpG islands for the promoter region of CD26/DPPIV. Multivariate analysis showed that CD26 expression is a favorable prognostic factor (hazard ratio, 2.94; P = .045)., Conclusions: We confirm the relevance of CD26 negativity in SS diagnosis and monitoring. Nevertheless, the presence of rare CD26+ cases suggests that a multiparameter flow cytometry approach should be used. Changes in methylation profile could account for phenotypical heterogeneity., (Copyright© by the American Society for Clinical Pathology.)

The purpose of the current study was to find novel rheumatoid arthritis (RA)-specific gene expression by simultaneously comparing the expression profiles of the synovial tissues from patients with RA, osteoarthritis (OA) and ankylosing spondylitis (AS). The Illumina Human HT-12 v4 Expression BeadChip was used to investigate the global gene expression profiles in synovial tissues from RA (n = 12), OA (n = 14) and AS (n = 7) patients. By comparing the profiles in synovial tissues from RA, OA and AS, we identified the CD38, ankyrin repeat domain 38 (ANKRD38), E2F transcription factor 2 (E2F2), craniofacial development protein 1 (CFDP1), cluster of differentiation (CD)7, interferon-stimulated exonuclease gene 20 kDa (ISG20) and interleukin-2 receptor gamma (IL)-2RG genes as differentially expressed gene expression in RA synovial tissues. The increased expression of CD38, E2F2 and IL-2RG, as revealed using real-time polymerase chain reaction (PCR) with synovial tissues from RA (n = 30), OA (n = 26) and AS patients (n = 20), was in agreement with the microarray data. Immunohistochemistry revealed significant CD38 expression and E2F2 in synovial membranes from RA patients (n = 5). The CD38(+) cells had high a percentage in the RA patients' blood (n = 103) and in the CD3(+) and CD56(+) subsets. The CD38(+) cell percentage was correlated significantly with RF level (P = 0·026) in RA patients. The IL-1α and IL-β levels were depressed significantly in the culture medium of RA synovial fibroblast cells (n = 5) following treatment with siRNAs targeting the E2F2 or CD38 genes. This study suggests that the uniquely increased expression of CD38 and E2F2 in RA synovial tissues contribute to the immunoactivation of the disease., (© 2014 British Society for Immunology.)

Tumor-associated macrophages (TAMs) have essential roles in tumor progression and metastasis. Tumor cells recruit myeloid progenitors and monocytes to the tumor site, where they differentiate into TAMs; however, this process is not well studied in humans. Here we show that human CD7, a T-cell and NK cell receptor, is highly expressed by monocytes and macrophages. Expression of CD7 decreases in M-CSF-differentiated macrophages and in melanoma-conditioned medium-induced macrophages (MCMI/Mφ) in comparison to monocytes. A ligand for CD7, SECTM1 (secreted and transmembrane protein 1), is highly expressed in many tumors, including melanoma cells. We show that SECTM1 binds to CD7 and significantly increases monocyte migration by activation of the PI3K (phosphatidylinositol 3'-kinase) pathway. In human melanoma tissues, tumor-infiltrating macrophages expressing CD7 are present. These melanomas, with CD7-positive inflammatory cell infiltrations, frequently highly express SECTM1, including an N-terminal, soluble form, which can be detected in the sera of metastatic melanoma patients but not in normal sera. Taken together, our data demonstrate that CD7 is present on monocytes and tumor macrophages and that its ligand, SECTM1, is frequently expressed in corresponding melanoma tissues, possibly acting as a chemoattractant for monocytes to modulate the melanoma microenvironment.

Objectives: To investigate the expression and function of CD74 in normal renal tissue and clear cell-renal cell carcinoma (ccRCC), as well as related renal tubule epithelial lines. We also analyzed the association between clinicopathological characteristics of ccRCCs and the expression levels of CD74., Methods: Immunostaining of CD74 was performed in 107 patients' renal tissue and cell lines. We evaluated the association between clinicopathological characteristics of ccRCC and CD74 levels using image analysis. CD74 expression levels were also analyzed by Western blot. Lentivirus-mediated CD74 knockdown inhibited the growth and invasion, of ccRCC cell lines 786-O in vitro and in vivo. Cell proliferation, apoptosis, and invasion as well as HIF-1α pathway-related proteins, were estimated by Western blot. All experiments were repeated at least 3 times., Results: Immunostaining and image analysis showed strong immunoreactions of CD74 in all patients' ccRCC tissue and malignant cell lines, while CD74 expression levels were associated with tumor grade (P = 0.013). Western blot indicated that ccRCC tissue and malignant cell lines expressed higher levels of CD74 and hypoxia inducible factor 1α (HIF-1α) than adjacent normal renal tissue and normal cell HK-2. Vitro and vivo tests demonstrated that lentivirus-mediated CD74 knockdown inhibited the proliferation of ccRCC cell lines, induced G1/S arrest and apoptosis, and inhibited invasion. Inhibition of CD74 resulted in down-regulation of HIF-1α pathway proteins., Conclusions: CD74 was overexpressed in human ccRCCs and associated with tumor grade, and inhibition of CD74 produced ccRCC proliferation arrest, induced apoptosis, and inhibited invasion, which impinged on HIF-1α pathway-related proteins. It might represent a potential therapeutic target for ccRCC., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Poly(amidoamine) (PAMAM) dendrimers are branched water-soluble polymers defined by consecutive generation numbers (Gn) indicating a parallel increase in size, molecular weight, and number of surface groups available for conjugation of bioactive agents. In this article, we compare the biodistribution of N-acetylgalactosamine (NAcGal)-targeted [(14) C]1 -G5-(NH2 )5 -(Ac)108 -(NAcGal)14 particles to non-targeted [(14) C]1 -G5-(NH2 )127 and PEGylated [(14) C]1 -G5-(NH2 )44 -(Ac)73 -(PEG)10 particles in a mouse hepatic cancer model. Results show that both NAcGal-targeted and non-targeted particles are rapidly cleared from the systemic circulation with high distribution to the liver. However, NAcGal-targeted particles exhibited 2.5-fold higher accumulation in tumor tissue compared to non-targeted ones. In comparison, PEGylated particles showed a 16-fold increase in plasma residence time and a 5-fold reduction in liver accumulation. These results motivated us to engineer new PEGylated G5 particles with PEG chains anchored to the G5 surface via acid-labile cis-aconityl linkages where the free PEG tips are functionalized with NAcGal or SP94 peptide to investigate their potential as targeting ligands for hepatic cancer cells as a function of sugar conformation (α versus β), ligand concentration (100-4000 nM), and incubation time (2 and 24 hours) compared to fluorescently (Fl)-labeled and non-targeted G5-(Fl)6 -(NH2 )122 and G5-(Fl)6 -(Ac)107 -(cPEG)15 particles. Results show G5-(Fl)6 -(Ac)107 -(cPEG[NAcGalβ ])14 particles achieve faster uptake and higher intracellular concentrations in HepG2 cancer cells compared to other G5 particles while escaping the non-specific adsorption of serum protein and phagocytosis by Kupffer cells, which make these particles the ideal carrier for selective drug delivery into hepatic cancer cells., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Here we have developed a versatile liposome-mediated drug delivery system (DDS) allowing a strong bridge between the streptavidin-tagged liposome (SAL) and biotin (Bi)-tagged biomaterials which has strong affinity to surface proteins expressed in restricted cell lineages. This DDS was effective and specific for many leukemia cells in vitro and in vivo. When examining 6 human leukemia cell lines using calcein-encapsulated SALs in combination with Bi-granulocyte colony-stimulating factor (G-CSF), Bi-anti-CD33 monoclonal antibody (MAb) or Bi-anti-CD7 MAb, the fluorescent positive rate of each cell line was in almost proportion to degree of G-CSF receptor, CD33 or CD7 expression, respectively. More importantly, the binding ability was shown to be well maintained in a mouse xenograft model. Furthermore the cytosine arabinoside (AraC)-encapsulated SALs could kill the corresponding cells much more effectively in combination with Bi-biomaterials than free AraC, as expected. These findings strongly indicate that our SAL/Bi-biomaterial system could allow various types of medical agents to be delivered reliably and stably to the cells targeted., (Copyright © 2013. Published by Elsevier B.V.)

Most T cell responses to pathogens or self antigens are modulated through the action of regulatory T cells and tissue-specific inhibitory mechanisms. To this end, several receptor-ligand pairs have evolved which either augment or diminish T cell function. Here we describe the tissue ligand SECTM1A (Secreted and transmembrane1A) as an alternative murine CD7 ligand. We show that SECTM1A, like SECTM1B, binds strongly to CD7, and that SECTM1B was able to compete with SECTM1A for CD7 binding. SECTM1A is ubiquitously expressed and has two major alternative transcripts which differ in expression between tissues. Both immobilised soluble forms of SECTM1A and SECTM1B and cell surface anchored forms demonstrated opposing effects on CD4+ T cell activation. Whereas SECTM1A acted as a co-stimulator of T cells, enhancing IL-2 production and proliferation, SECTM1B proved inhibitory to TCR mediated T cell activation. Surprisingly, both functional outcomes proved to be CD7-independent, indicating the existence of alternative receptors for both ligands. We used a SECTM1A-Fc fusion protein to immunoprecipitate potential alternative ligands from detergent lysates of CD7(-/-) T cells and, using mass spectrometry, identified GITR as a SECTM1A binder. SECTM1A was found to bind to activated CD4+ and CD8+ T cells as well as to CHO cells expressing cell surface GITR. Binding of SECTM1A to activated primary T cells was inhibited by either GITRL-Fc or anti GITR antibodies. Thus SECTM1A and SECTM1B represent novel reciprocal alternative ligands which may function to modulate the activation of effector and regulatory T cells. The ability of SECTM1A to activate T cells may be explained by its ability to bind to GITR.

T cell precursors are an attractive target for adoptive immunotherapy. We examined the regulation of human early T lymphopoiesis by human bone marrow stromal cells to explore in vitro manipulation of human T cell precursors in a human-only coculture system. The generation of CD7(+)CD56(-)cyCD3(-) proT cells from human hematopoietic progenitors on telomerized human bone marrow stromal cells was enhanced by stem cell factor, flt3 ligand, and thrombopoietin, but these stimulatory effects were suppressed by interleukin 3. Expression of Notch ligands Delta-1 and -4 on stromal cells additively promoted T cell differentiation into the CD7(+)cyCD3(+) pre-T cell stage, while cell growth was strongly inhibited. By combining these coculture systems, we found that initial coculture with telomerized stromal cells in the presence of stem cell factor, flt3 ligand, and thrombopoietin, followed by coculture on Delta-1- and -4-coexpressing stromal cells led to a higher percentage and number of pre-T cells. Adoptive immunotherapy using peripheral blood T cells transduced with a tumor antigen-specific T cell receptor (TCR) is a promising strategy but has several limitations, such as the risk of forming a chimeric TCR with the endogenous TCR. We demonstrated that incubation of TCR-transduced hematopoietic progenitors with the combination of coculture systems gave rise to CD7(+)TCR(+)CD3(+)CD1a(-) T cell precursors that rapidly proliferated and differentiated under the culture condition to induce mature T cell differentiation. These data show the regulatory mechanism of early T lymphopoiesis on human stromal cells and the potential utility of engineered human stromal cells to manipulate early T cell development for clinical application., (Copyright © 2013 ISEH - Society for Hematology and Stem Cells. Published by Elsevier Inc. All rights reserved.)

Background: Mutations in NPM1 and FLT3 genes represent the most frequent genetic alterations and important diagnostic and prognostic indicators in patients with acute myeloid leukemia (AML)., Objective: We investigated the prevalence and clinical characteristics of NPM1 and FLT3 mutations in 161 patients of de novo AML including adults and children., Results: NPM1 mutation was found in 21% and FLT3 mutation in 25% of the AML patients. Thirteen (8%) samples were positive for both NPM1 and FLT3/ITD mutations. Adult patients had significantly higher frequency of NPM1 mutation than children (25.8% versus 8.8%; P = 0.02). Further, NPM1 mutation was found to be more frequent in patients above 45 years of age (P = 0.02). NPM1 mutation was significantly associated with higher platelet count (P = 0.05) and absence of hepatosplenomegaly (P = 0.01), while FLT3/ITD mutation was associated with higher white blood count (P = 0.01). Immunophenotypically, NPM1 mutation was associated with the lack of CD34 (P < 0.001) and HLD-DR expression (P < 0.001), while FLT3/ITD mutation was positively associated with the expression of CD7 (P = 0.04). No correlation was found between NPM1 mutation and fusion gene. Interestingly, FLT3/ITD mutation was found to be inversely associated with AML/ETO fusion gene (P = 0.04)., Conclusions: The results suggest that distinct clinical and immunophenotypic characteristics of NPM1 and FLT3/ITD mutations present further insight into the molecular mechanism of leukemogenesis.

Introduction: The classification of acute leukemias has revolutionized over the years. Immunophenotyping of acute leukemia has gained popularity because of its influence on treatment and prognosis of the disease. The various antigens expressed by the leukemic cells can be assessed by flowcytometry (FCA) and can be used in rendering specific treatment and predicting the outcome of the different types of acute leukemia., Aims: The main aim of this study was to compare the morphologic and cytochemical diagnoses with flowcytometric diagnoses in acute leukemia and to analyze the usefulness of FCA over morphology., Results: In this study we analyzed 50 cases of acute leukemia and found concordance rate as high as 86% between morphologic/cytochemical diagnosis and flowcytometric diagnosis. Of these, complete concordance was seen in 58% of the cases and partial concordance was seen in 22% of the cases. Non-concordance was seen in only 4% of our cases. In remaining 16% of our cases FCA helped in sub classifying the acute leukemia where morphology and cytochemistry had failed to do so. CD19 and 20 were found to be consistent B-cell markers and CD3 was a very specific marker for T-cell leukemia. CD13 and 33 were important myeloid markers and were aided by other secondary panel of markers like CD14, CD117 and CD41., Conclusion: FCA not only helps in confirming morphologic diagnosis in acute leukemia but also helps in assigning specific lineage to the blasts, particularly in acute lymphoid leukemia. Immunophenotyping is of utmost importance in classifying acute leukemia as it greatly influences the treatment and the prognosis.

Purpose: In a recent study to purify adult T-cell leukemia-lymphoma (ATL) cells from acute-type patients by flow cytometry, three subpopulations were observed in a CD3 versus CD7 plot (H: CD3(high)CD7(high); D: CD3(dim)CD7(dim); L: CD3(dim)CD7(low)). The majority of leukemia cells were enriched in the L subpopulation and the same clone was included in the D and L subpopulations, suggesting clonal evolution. In this study, we analyzed patients with indolent-type ATL and human T-cell leukemia virus type I (HTLV-I) asymptomatic carriers (ACs) to see whether the CD3 versus CD7 profile reflected progression in the properties of HTLV-I-infected cells., Experimental Design: Using peripheral blood mononuclear cells from patient samples, we performed multi-color flow cytometry. Cells that underwent fluorescence-activated cell sorting were subjected to molecular analyses, including inverse long PCR., Results: In the D(%) versus L(%) plot, patient data could largely be categorized into three groups (Group 1: AC; Group 2: smoldering- and chronic-type ATL; and Group 3: acute-type ATL). Some exceptions, however, were noted (e.g., ACs in Group 2). In the follow-up of some patients, clinical disease progression correlated well with the CD3 versus CD7 profile. In clonality analysis, we clearly detected a major clone in the D and L subpopulations in ATL cases and, intriguingly, in some ACs in Group 2., Conclusion: We propose that the CD3 versus CD7 plot reflects progression of disease stage in patients infected with HTLV-I. The CD3 versus CD7 profile will be a new indicator, along with high proviral load, for HTLV-I ACs in forecasting disease progression.

We conducted a multicenter, flow cytometry study to validate differences in immunophenotypes among disease types in melodysplastic syndromes (MDS). The data obtained from 115 patients were combined into three groups according to disease grade, i.e., low-grade MDS, refractory anemia with excess blasts, and acute leukemia transformed from MDS (AL-MDS). The data comparison showed that with the progression of disease grade, the immunophenotypes of CD34(+) myeloblasts were more immature, with an increase and a decrease in CD7 and CD15 expression, respectively, and the percentages of CD34(+) B-progenitors among total CD34(+) cells and the granularity of granulocytes decreased. Logistic regression analyses showed that, in addition to myeloblast percentages, the expression of CD7 and B7-H1 on myeloblasts was independently associated with AL-MDS patients., (Copyright © 2012 Elsevier Ltd. All rights reserved.)