Cell Development In Thymus Research Articles

Impact of perinatal administration of probiotics on immune cell composition in neonatal mice.

Newborns and especially preterm infants are much more susceptible to infections than adults. The pathogens causing infections in newborns are often detectable in the intestinal flora of affected children even before disease onset. Therefore, it seems reasonable to prevent dysbiosis in newborns and preterm infants. An approach followed in many neonatal intensive care units (NICUs) is to prevent infections in preterm infants with probiotics however their mechanisms of action of probiotics are incompletely understood. Here, we investigated the effect of perinatal probiotic exposure on immune cells in newborn mice. Pregnant mice were orally treated with a combination of Lactobacillus acidophilus and Bifidobacterium bifidum (Infloran®) from mid-pregnancy until the offspring were harvested. Immune cell composition in organs of the offspring were analyzed by flow cytometry. Perinatal probiotic exposure had profound effects on immune cell composition in the intestine, liver and lungs of newborn mice with reduction of myeloid and B cells and induction of T cells in the probiotic treated animals' organs at weaning. Furthermore, probiotic exposure had an effect on T cell development in the thymus. Our results contribute to a better understanding of the interaction of probiotics with the developing immune system. probiotics have profound effects on immune cell composition in intestines, livers and lungs of newborn mice. probiotics modulate T cell development in thymus of newborn mice. effects of probiotics on neonatal immune cells are particularly relevant in transition phases of the microbiome. our results contribute to a better understanding of the mechanisms of action of probiotics in newborns.

RIPK1 deficiency prevents thymic NK1.1 expression and subsequent iNKT cell development.

Receptor Interacting Protein Kinase 1 (RIPK1) and caspase-8 (Casp8) jointly orchestrate apoptosis, a key mechanism for eliminating developing T cells which have autoreactive or improperly arranged T cell receptors. Mutations in the scaffolding domain of Ripk1 gene have been identified in humans with autoinflammatory diseases like Cleavage Resistant RIPK1 Induced Autoinflammatory (CRIA) and Inflammatory Bowel Disease. RIPK1 protein also contributes to conventional T cell differentiation and peripheral T cell homeostasis through its scaffolding domain in a cell death independent context. Ripk1 deficient mice do not survive beyond birth, so we have studied the function of this kinase in vivo against a backdrop Ripk3 and Casp8 deficiency which allows the mice to survive to adulthood. These studies reveal a key role for RIPK1 in mediating NK1.1 expression, including on thymic iNKT cells, which is a key requirement for thymic stage 2 to stage 3 transition as well as iNKT cell precursor development. These results are consistent with RIPK1 mediating responses to TcR engagement, which influence NK1.1 expression and iNKT cell thymic development. We also used in vivo and in vitro stimulation assays to confirm a role for both Casp8 and RIPK1 in mediating iNKT cytokine effector responses. Finally, we also noted expanded and hyperactivated iNKT follicular helper (iNKTFH) cells in both DKO (Casp8-, Ripk3- deficient) and TKO mice (Ripk1-, Casp8-, Ripk3- deficient). Thus, while RIPK1 and Casp8 jointly facilitate iNKT effector function, RIPK1 uniquely influenced thymic iNKT cell development most likely by regulating molecular responses to T cell receptor engagement. iNKT developmental and functional aberrances were not evident in mice expressing a kinase-dead version of RIPK1 (RIPK1kd), indicating that the scaffolding function of this protein exerts the critical regulation of iNKT cells. Our findings suggest that small molecule inhibitors of RIPK1 could be used to regulate iNKT cell development and effector function to alleviate autoinflammatory conditions in humans.

Synergistic regulation of Notch signaling by different O-glycans promotes hematopoiesis.

Glycosylation of Notch receptors by O-fucose glycans regulates Notch ligand binding and Notch signaling during hematopoiesis. However, roles in hematopoiesis for other O-glycans that modify Notch receptors have not been determined. Here we show that the EGF domain specific GlcNAc transferase EOGT is required in mice for the optimal production of lymphoid and myeloid cells. The phenotype of Eogt null mice was largely cell-autonomous, and Notch target gene expression was reduced in T cell progenitors. Moreover, EOGT supported residual Notch signaling following conditional deletion of Pofut1 in hematopoietic stem cells (HSC). Eogt : Pofut1 double mutant HSC had more severe defects in bone marrow and in T and B cell development in thymus and spleen, compared to deletion of Pofut1 alone. The combined results show that EOGT and O-GlcNAc glycans are required for optimal hematopoiesis and T and B cell development, and that they act synergistically with POFUT1 and O-fucose glycans to promote Notch signaling in lymphoid and myeloid differentiation.

Analyses of thymocyte commitment to regulatory T cell lineage in thymus of healthy subjects and patients with 22q11.2 deletion syndrome.

The Chromosome 22q11.2 deletion syndrome (22q11.2DS) results in an inborn error of immunity due to defective thymic organogenesis. Immunological abnormalities in 22q11.2DS patients are thymic hypoplasia, reduced output of T lymphocytes by the thymus, immunodeficiency and increased incidence of autoimmunity. While the precise mechanism responsible for increased incidence of autoimmunity is not completely understood, a previous study suggested a defect in regulatory T cells (Treg) cell lineage commitment during T cell development in thymus. Here, we aimed to analyze this defect in more detail. Since Treg development in human is still ill-defined, we first analyzed where Treg lineage commitment occurs. We performed systematic epigenetic analyses of the Treg specific demethylation region (TSDR) of the FOXP3 gene in sorted thymocytes at different developmental stages. We defined CD3+CD4+CD8+ FOXP3+CD25+ as the T cell developmental stage in human where TSDR demethylation first occurs. Using this knowledge, we analyzed the intrathymic defect in Treg development in 22q11.2DS patients by combination of TSDR, CD3, CD4, CD8 locus epigenetics and multicolor flow cytometry. Our data showed no significant differences in Treg cell frequencies nor in their basic phenotype. Collectively, these data suggest that although 22q11.2DS patients present with reduced thymic size and T cell output, the frequencies and the phenotype of Treg cell at each developmental stage are surprisingly well preserved.

CD226 knockout reduces the development of CD8+ T by impairing the TCR sensitivity of double-positive thymocytes.

The costimulation molecule CD226 is widely involved in T cell differentiation, activation and immune functional regulation in peripheral immune tissues. CD226-deficient mice have impaired immune response capacity. The function of CD226 in regulating T cell development in the thymus, a central immune organ, is not yet fully understood. We investigated the development of thymocytes using CD226 knockout mice and single-cell sequencing techniques. CD226 began to be expressed in the second half of thymocyte development, with a gradual increase from the double-positive (DP) to single-positive (SP) phase and higher levels of CD226 on CD8+ T cells than on CD4+ T cells from the SP phase to mature T cells. In the thymus of CD226KO mice, the proportion of DPT at the quiescent phase (DPT-Q) increased, of which the Gzma+ cluster that tends to be CD8+ T cells and CD5+ cluster that is undergoing positive selection decreased dramatically. Afterward, the proportion of mature CD8+ T cells reduced dramatically. Depletion of CD226 impaired TCR activation signalling and diminished AKT/ERK/NF-κB/p38 phosphorylation levels. The diminished TCR responsiveness of DPT cells impeded their positive selection process and influenced the maturation of CD8+ T cells. In mechanism, CD226 knockout enhanced DPT cell apoptosis via impairing AKT phosphorylation. These results suggest that CD226 plays a significant role in T cell thymic development via modulation of TCR signalling, affecting CD8+ T cell maturation.

Cell-intrinsic expression of the hemichannel Pannexin-1 promotes effector and memory CD8+ T cells via distinct metabolic pathways

Abstract Tissue-derived extracellular ATP (eATP) is a “danger signal” sensed by immune cells via purinergic receptors (e.g. P2RX7). In addition, healthy cells can export eATP through transmembrane channels, such as the hemichannel Pannexin-1 (Panx1). CD8+ T cells express Panx1 constitutively throughout developmental and immune response stages. However, the biological role of Panx1 in CD8+ T cells is undefined. Here, we used genetic and pharmacological tools to address this question. T-cell specific Panx1 deletion did not affect CD8+ T cell thymic development. In contrast, CD8+ T cell responses to viral infection (LCMV) are impaired by Panx1 inhibition or deletion. This is true for effector expansion of CD8+ T cells and for the survival of memory CD8+ T cells. Using adoptive transfer of tamoxifen-conditional Panx1 knockout LCMV-specific (P14) cells into LCMV-infected mice, we showed that memory CD8+ T cell survival requires sustained Panx1 – except for small intestinal-resident cells. Mechanistically, Panx1 promotes memory CD8+ T cell survival via P2RX7, which also favors memory CD8+ T cells - as suggested by our data with Panx1/P2RX7-double knockout P14 cells. The role of Panx1 for effector CD8+ T cell expansion, however, is unlikely to be via P2RX7 since this receptor does not have a role in effector CD8+ T cells. Our transcriptional and metabolic data suggests that, while memory CD8+ T cells require Panx1 for optimal mitochondrial function and expression of pro-memory genes, effector CD8+ T cells lacking Panx1 had decreased activation of the glycolytic pathway. Collectively, these results suggest that, in response to acute virus, Panx1 induces CD8+ T cell effector expansion and memory survival through distinct metabolic pathways. Supported by grants from NIH (R00 AI139381, NIAID).

Gangliosides in T cell development and function of mice.

The molecular diversity of glycosphingolipids (GSLs) that arouse during thecourseof evolution clearly plays an essential role in maintenance of biological homeostasis. Why is such a wide variety of GSLs necessary, and what gave rise to the expression mechanisms that are selective and specific to individual cells, tissues, or organs? What is the biological significance of these mechanisms? The same questions apply to GSLs involved in T cell development and activation.Primary CD4+ T cells and CD8+ T cells preferentially express differing ganglioside series: a-series and o-series, respectively. Conversely, a-series and o-series ganglioside deficiency results respectively in CD4+ and CD8+ T cell dysfunction. Dynamic changes in ganglioside expression occur during T cell development in thymus. Ganglioside GM3 synthase deficiency, which results in lack of a-series gangliosides, ameliorated CD4+ T cell-mediated airway hypersensitivity in a mouse model of allergic asthma. In this review, we summarize findings from these and many studies to illustrate the key roles of gangliosides in T cell differentiation and function.

Thpok promotes CD4+-lineage differentiation by recruiting the NuRD chromatin remodeling complex

Abstract T cell precursors develop into helper CD4 or cytotoxic CD8 T cells in thymus. Thpok, a BTB/POZ family transcription factor, enforces MHC II restricted thymocytes commitment to the CD4 lineage, while Runx3 protein drives MHC I restricted thymocytes to the CD8 lineage. However, the molecular mechanisms underlying Thpok functions during CD4 T cell development are not understood. Replacing the BTB domain from Thpok with that from Bcl6, another BTB/POZ zinc finger transcription factor that recruits NCOR-family co-repressors through its BTB domain, abrogated CD4 T cell development in thymus; this suggests a unique feature associated with Thpok BTB domain. Here, using mass-spectrometry, we identified nucleosome remodeling and deacetylase (NuRD) complex as a novel Thpok cofactor. We demonstrated that the Thpok BTB domain is essential for NuRD recruitment. Moreover, we identified BTB domain amino acid residues critical for NuRD complex interaction, and showed that mutation of these Thpok residues disrupts CD4 T cell development in vivo. Reciprocally, a fusion protein reconstituting NuRD binding to a BTB-less version of Thpok (which cannot bind NuRD) restored CD4 T cells in vivo. In addition, we found that CD4-lineage thymocytes expressing that fusion protein have a transcriptome similar to that of thymocytes expressing wild type Thpok. Finally, we found that NuRD binding is required for Thpok to antagonize Runx3 expression in thymocytes. Thus, our results demonstrate that NuRD recruitment is both necessary and sufficient for the functions of the Thpok BTB domain in CD4 T cell development and it is also required to antagonize Runx3-dependent differentiation towards CD8 lineage.

The ATP-Exporting Hemichannel Pannexin-1 Promotes CD8+ T Cell Memory Establishment

Abstract Release of extracellular ATP (eATP) by dying cells is often identified as a "danger signal" by immune cells. However, eATP export by healthy cells is common, and a major transmembrane ATP exporter is the Pannexin 1 (Panx1) molecule. CD8+ T cells express Panx1 during thymic development, at steady-state and during immune response. However, the role of Panx1 on CD8+ T cell-mediated immune response is not well defined. Here, we used genetic and pharmacological ablation tools to address this question. T cell-specific Panx1 deletion does not affect CD8+ T cell thymic development or effector responses to viral infection (LCMV). In contrast, memory CD8+ T cell establishment is impaired by either pharmacological inhibition or CD8-specific Panx1 deletion. Using a tamoxifen-controlled, conditional Panx1 knockout LCMV-specific (P14) CD8+ T cell system, we found that both memory CD8+ T cell generation and survival rely on Panx1. In vitro data further supports these findings: two Panx1 inhibitors, 10Panx and Probenecid, reduce the expression of the central memory marker CD62L. Panx1-deficient CD8+ T cells develop a memory-like phenotype in response to IL-15, but fail to engage mitochondrial respiration and present decreased mitochondrial membrane potential, suggesting Panx1 promotes optimal mitochondrial function. These defects are partially reverted with exogenous eATP. Collectively, our data indicates that cell-intrinsic Panx1-mediated eATP export favors memory CD8+ T cell differentiation. We are currently testing whether CD8-intrinsic Panx1 controls memory CD8+ T cell generation solely as an autocrine eATP source, or if Panx1 also serves as a “rheostat” controlling intracellular ATP levels in antigen-responding CD8+ T cells.

Redefining the targets of the vitamin D receptor (VDR) utilizing a novel VDR reporter mouse.

Abstract The vitamin D receptor (VDR) is a ligand-activated nuclear protein that regulates gene transcription. Vitamin D target cells are identified by the expression of VDR. Kidney and colon epithelial cells constitutively express high levels of the VDR. Immune cells also express the VDR; however, at significantly lower levels. Western blots show very low expression of the VDR in spleen, and lymph nodes. Gene expression studies in macrophage, B cells and T cells showed that activation for 24–48 hours increased the VDR mRNA levels. We have developed transgenic mice that express Cre recombinase within the VDR locus (VDRcre) and crossed these with a reporter line (Tdtomatofl/fl). Cre expression in the VDR locus results in a VDR +/− mice. The frequencies of immune cells were similar between VDR−/− and VDR +/− mice. The VDRcre expressing offspring had pink skin. Kidneys, small intestine and colon were also distinctly pink suggesting high expression of the Tdtomato-VDR reporter. Splenic T cells, activated with CD3e antibody showed upregulation of VDR mRNA and protein. Regardless of activation status, naive, effector or memory T cells had similar and high levels of the VDR reporter. VDR expression was detected at various stages of T cell thymic development with a 80% in the CD4-CD8- cells and 90% of CD4+CD8+ cells, 84% CD4+ and 88% CD8+ thymocytes. High expression of the VDR reporter in multiple T cell types and precursors suggests that the VDR is expressed throughout the life of a T cell. Future work will identify immune cells negative for the VDR reporter and the kinetics of VDR expression following activation in various cell types.

Critical role for adhesion and degranulation promoting adaptor protein in homeostasis and function of invariant natural killer T cells

Abstract Invariant natural killer T cells (iNKTs) are innate T lymphocytes that are critical in modulating immune response in cancer, infection and inflammation. However, the mechanisms that regulate iNKT cell development and function are not fully known. In the current study, we demonstrate that adhesion and degranulation promoting adaptor protein (ADAP) is dispensable for iNKT cell thymic development but is required for their peripheral maintenance. Strikingly, ADAP-deficient (Adap−/−) mice have significantly reduced iNKTs in the periphery that is associated with decreased surface expression of the critical homing receptor (CXCR6), homeostatic proliferation and increased apoptosis. Consistently, Adap−/− iNKTs have markedly reduced expression of pro-survival factors (PLZF, ICOS, GATA-3 and Id2) but increased levels of pro-apoptotic molecules (Bax, Bad and Bim). Functionally, Adap−/− iNKTs have significantly reduced cytokine production and bystander immune cell activation as well as poor anti-tumor response, both in vitro and in vivo. In agreement with these findings, ADAP-silenced human iNKTs have remarkably impaired cytokine production and cytotoxicity against leukemia targets in vitro. Mechanistically, preformed transcripts for interleukin (IL)-4 and IFN-g as well as several microRNAs are reduced in Adap−/− iNKTs. Additionally, these cells exhibit reduced capacity to form conjugates and have diminished actin polymerization at the immunological synapse. Collectively, our findings establish a novel and pivotal role for ADAP in iNKT cell homeostasis and function.

Retroviral Gene Transduction into T Cell Progenitors for Analysis of T Cell Development in the Thymus.

The thymus is an organ where T cells develop throughout life. Using mice as a model animal, molecular mechanisms of intrathymic T cell development have been studied. Fetal thymus organ culture technique enables ex vivo reconstitution of fetal-specific T cell development, while bone marrow chimera technique allows in vivo reconstitution of T cell development in adult thymus. These techniques can be combined with retroviral gene transduction into the T cell progenitors to evaluate the function of genes of interest in developing T cells. Here, we describe the basic protocols for retrovirus gene transduction into fetal or adult T cell progenitors and reconstitution of thymic T cell development including experimental tips such as using cryopreserved fetal liver or bone marrow cells as sources of T cell progenitors.

Complex and Multilayered Role of IL-21 Signaling during Thymic Development

Unlike IL-7, which is known to be critical for T cell thymic development, the role of IL-21 in this process is still controversial. IL-21 has been shown to accelerate thymic recovery in mice treated with glucocorticoids and revives the peripheral T cell pool in aged animals. However, mice with a defect in IL-21 signaling exhibit normal thymic cellularity, challenging the importance of this cytokine in the thymic developmental process. Using mixed bone marrow chimeric mice, our studies describe a multilayered role for IL-21 in thymopoiesis. In this system, IL-21R-deficient cells are unable to compete with wild-type populations at different stages of the thymic development. Using a mixed bone marrow chimeric animal model, IL-21 seems to be involved as early as the double-negative 1 stage, and the cells from the knockout compartment have problems transitioning to subsequent double-negative stages. Also, similar to IL-7, IL-21 seems to be involved in the positive selection of double-positive lymphocytes and appears to play a role in the migration of single-positive T cells to the periphery. Although not as critical as IL-7, based on our studies, IL-21 plays an important complementary role in thymic T cell development, which, to date, has been underrecognized.

Jeju ground water containing vanadium induces normal T cell development and immune activation in chronically stressed mice.

Containing high concentration of vanadium served by the volcanic bedrock, Jeju ground water has long been known for various implicit health benefits including immune-promotion. Exposure to stress has been reported to be associated with immunosuppression such as reducing lymphocyte population or antibody production due to stress hormones. In this study, we aimed at evaluating the effects of Jeju ground water on chronically stressed mice. C57BL/6 mice were subjected to various stressors such as restraint stress, water swimming stress, heat stress, acoustic stress, and Jeju ground water was supplied for 28days with two different concentrations, S1 (vanadium 15-20μg/l, pH 8.3) and S2 (vanadium 20-25μg/l, pH 8.5). Treatment with Jeju ground water increased CD4+CD8- or CD4-CD8+ single-positive thymocytes. It also increased the proliferation of splenocytes and the populations of CD4+ T cells, CD45R/B220+ B cells, CD11b+ macrophages or Gr-1+ granulocytes in spleen. In addition, the production of IgG was increased in chronically stressed mice by treatment with Jeju ground water. These results suggest vanadium-rich Jeju ground water may be helpful in T cell development in thymus and immune cell proliferation and its function in spleen against chronic stress.

Interleukin-23 deficiency alters thymic selection in lupus-prone mice.

We have previously reported that IL-23 receptor deficiency in MRL.lpr mice ameliorates lupus by altering the balance of pro- and anti-inflammatory cytokines in secondary lymphoid organs. As IL-23 may also impact thymic selection, we evaluated the effect of IL-23 on thymic T cell development in lupus-prone mice. We generated IL-23p19-deficient MRL.lpr mice and harvested their thymus at 8 weeks of age. We found that the late stage double negative DN4 population was increased in IL-23p19-/- MRL.lpr mice when compared to IL-23p19+/+ MRL.lpr mice. Despite this, mature thymocytes (CD24-TCRβ+) were decreased by more than 50% in the IL-23p19-deficient mice versus wild-type controls. This was associated with a decrease in the generation of CD8+ T cells, possibly through downregulation of the IL-7 receptor. CD8+ T cells were not only fewer in numbers but also had decreased expression of the migration-related receptors CD44 and CD62L in the thymus and spleens of IL-23p19-deficient versus wild-type mice. We propose that IL-23 promotes the development of lupus-like autoimmunity not only through T cell polarization and cytokine production in the peripheral lymphoid organs but also by influencing T cell thymic development.

CD5 expression influences T cell metabolism and mice behavior

Abstract T cells are key players in the adaptive immune response and undergo metabolic changes upon activation. CD5 is a co-receptor found on T cells and plays a significant role in regulating T cell thymic development, intracellular signaling and cytokine production. Previous studies have found that naïve T cells with high CD5 expression (CD5hi) have increased TCR signal strength and enhances immune response to foreign peptide in the periphery. Additionally, we have reported that CD5hi naïve T cells have higher calcium mobilization and improved T cell activation compared to CD5lo T cells. Calcium influx levels can modulate and influence metabolic changes in T cells. Thus, we hypothesized that CD5hi, CD5lo and CD5 deficient T cells have different bioenergetic demands that affect metabolic pathways and T cell activation. We evaluated the effects of CD5 levels on metabolism using CD5 deficient mice vs wild type controls and found CD5 deficient T cells had significant differences in metabolic function. Recently published work has described a connection between increased T cell metabolism and altered cognitive function in PD-1 deficient mice. We have also found significant differences between CD5 deficient and wild type mice in marble burying rates, elevated plus and water maze behavior and open field activity. These behavioral test results suggest CD5 deficient mice have altered cognitive function and higher levels of anxiety. Thus, CD5 deficiency alters T cell metabolic and cognitive function.

The Bacterial Peptidoglycan-Sensing Molecules NOD1 and NOD2 Promote CD8+ Thymocyte Selection.

Nucleotide-binding and oligomerization domain (NOD)-like receptors NOD1 and NOD2 are cytosolic innate immune receptors that recognize microbial peptidoglycans. Although studies have addressed the role of NOD proteins in innate immune responses, little attention has been given to their impact on the developing adaptive immune system. We have assessed the roles of NOD1 and NOD2 deficiency on T cell development in mice. Our results demonstrate that NOD1 and NOD2 promote the positive selection/maturation of CD8 single-positive thymocytes in a thymocyte-intrinsic manner. TCR-mediated ERK phosphorylation is significantly reduced in the absence of NOD proteins, but receptor-interacting protein 2 is not involved in CD8 single-positive thymocyte selection or ERK signaling. Commensal bacteria-free animals have thymocyte maturation defects, and exogenous NOD ligands can enhance thymocyte maturation in culture. These results raise the intriguing possibility that abnormal lymphocyte responses observed in NOD-dependent inflammatory diseases are not driven solely by microbial signals in the gut, but may also involve intrinsic lymphocyte defects resulting from impaired CD8 T cell thymic development.

Thyrotropin Alters T Cell Development in the Thymus in Subclinical Hypothyroidism Mouse Model.

Subclinical hypothyroidism (SCH) is highly prevalent in the general population and is associated with potential deleterious effects. Although developing T cells express thyroid-stimulating hormone receptor (TSH-R), the changes of T cell development in thymus in SCH have not been fully clarified. SCH mouse model, which is characterized by elevated serum TSH but similar thyroid hormone levels, was used to study the role of TSH in T cell development. Thymus weight of SCH mice increased 18% compared with controls. Importantly, the frequencies of CD4+ and CD8+ single-positive (SP) thymocytes increased 38% and 44%, respectively. We demonstrated that TSH protected thymocytes from apoptosis as evidenced by a significant decrease of Annexin V-positive thymocytes in SCH mice. Further analysis showed that extracellular-regulated kinases (ERK) 1/2 in thymus were activated in SCH mice. With analysis of T cell receptor excision circles (TREC), we found that TSH increased recent thymic emigrants (RTE) in spleen tissue in SCH mice. Thus, these results suggest that TSH promoted T cell development and enhanced the thymic recent output in SCH mice, possibly by suppression of apoptosis of thymocytes, indicating that modification of the ERK signalling pathways.

Abnormal Expression of the Chemokine (C-C Motif) Ligand 17 Gene in Adult B-Cell Acute Lymphoblastic Leukemia

AbstractBackground: Chemokine (C-C Motif) Ligand 17 is a protein coding gene. This chemokine plays important roles in T cell development in thymus as well as in trafficking and activation of mature T cells. Diseases associated with CCL17 include mycosis fungoides, paragonimiasis and some hematologic malignancies such as Hodgkin¡¯s lymphoma, B cell lymphoma, and Nasal natural killer/T cell lymphoma (NNKTL). However, our knowledge of the expression levels of CCL17 in B-cell acute lymphoblastic leukemia (ALL) remains limited.Aims: The purpose of this study was to investigate the expression levels of human CCL17 messenger RNA in adult B-cell ALL.Methods: A real-time quantitative reverse transcription-polymerase chain reaction assay based on TaqMan fluorescence methodology was used to quantify the CCL17 mRNA copy number in the bone marrow cells from patients with adult leukemia and in 16 human hematologic malignant cell lines. Normal marrow samples from the allogeneic stem cell transplantation donors were served as control. Informed consent was obtained for every marrow sample.Results:Expression levels of the CCL17 gene in leukemic cell lines, leukemia patients and normal donor marrow are shown in Figure 1. These results showed that the relative levels of CCL17 gene expression in marrow from 189 newly diagnosed B-cell ALL(median 0.23%; range 0%¡«69000%) was significantly higher than those of bone marrow from the 43 healthy donors (median 0.05%; range 0%¡«6.87%;P =0.0007). Significant CCL17 mRNA overexpression was found in the de novo B-cell ALL patients compared with 102 treated B-cell ALL patients(median 0.02%; range 0%¡«3339%) who achieved complete remission or 70 de novo AML (median 0.02%; range 0%¡«9.132%;P¡¯s <0.0001). The expression levels of CCL17 was higher in 21 refractory/relapsed B-cell ALL patients (median 0.68%; range 0.003%¡«13490%) than that newly diagnosed B-cell ALL, but no statistical significant difference was observed (P=0.34). Besides, no statistical significant difference was observed in 16 newly diagnosed T-cell ALL(median 0.06%, range 0%¡«9.947%), 70 AML and 43 healthy donors (P¡¯s > 0.05), but it was higher in SupB15 and Nalm-6 cells from B-cell ALL cell lines than in other cells from AML or T-cell ALL cell lines.Conclusion: These results suggest that abnormal expression of CCL17 in leukemia may be involved in the pathomechanism of B-cell ALL. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Id2 regulates hyporesponsive invariant natural killer T cells.

While the invariant natural killer T (iNKT)-cell response to primary stimulation with the glycolipid, α-galactosylceramide (αGalCer), is robust, the secondary response to this stimulus is muted resulting in a hyporesponsive state characterized by anti-inflammatory interleukin-10 (IL-10) production and high expression of programmed cell death 1 (PD1) and neuropilin 1 (NRP1). The E protein transcription factors and their negative regulators, the Id proteins, have previously been shown to regulate iNKT cell thymic development, subset differentiation and peripheral survival. Here, we provide evidence that the expression of the transcriptional regulator Id2 is downregulated upon stimulation of iNKT cells with their cognate antigen. Moreover, loss of Id2 expression by iNKT cells resulted in a hyporesponsive state, with splenic Id2-deficient iNKT cells expressing low levels of TBET, high levels of PD1 and NRP1 and production of IL-10 upon stimulation. We propose that downregulation of Id2 expression is an essential component of induction of the anti-inflammatory, hyporesponsive state in iNKT cells.