scholarly journals Expansion and long-range differentiation of the NKT cell lineage in mice expressing CD1d exclusively on cortical thymocytes

2005 ◽  
Vol 202 (2) ◽  
pp. 239-248 ◽  
Author(s):  
Datsen G. Wei ◽  
Hyunji Lee ◽  
Se-Ho Park ◽  
Lucie Beaudoin ◽  
Luc Teyton ◽  
...  
Keyword(s):  
Cell Lineage ◽  
Cell Types ◽  
Interferon Γ ◽  
Interleukin 4 ◽  
Thymic Epithelial Cells ◽  
Nkt Cell ◽  
Extensive Cell ◽  
Cell Type Specific ◽  
Necessary And Sufficient ◽  
Antigen Presenting

Unlike conventional major histocompatibility complex–restricted T cells, Vα14-Jα18 NKT cell lineage precursors engage in cognate interactions with CD1d-expressing bone marrow–derived cells that are both necessary and sufficient for their thymic selection and differentiation, but the nature and sequence of these interactions remain partially understood. After positive selection mediated by CD1d-expressing cortical thymocytes, the mature NKT cell lineage undergoes a series of changes suggesting antigen priming by a professional antigen-presenting cell, including extensive cell division, acquisition of a memory phenotype, the ability to produce interleukin-4 and interferon-γ, and the expression of a panoply of NK receptors. By using a combined transgenic and chimeric approach to restrict CD1d expression to cortical thymocytes and to prevent expression on other hematopoietic cell types such as dendritic cells, macrophages, or B cells, we found that, to a large extent, expansion and differentiation events could be imparted by a single-cognate interaction with CD1d-expressing cortical thymocytes. These surprising findings suggest that, unlike thymic epithelial cells, cortical thymocytes can provide unexpected, cell type–specific signals leading to lineage expansion and NKT cell differentiation.

scholarly journals Differential Regulation of Cathepsin S and Cathepsin L in Interferon γ–treated Macrophages

2003 ◽  
Vol 197 (2) ◽  
pp. 169-179 ◽  
Author(s):  
Courtney Beers ◽  
Karen Honey ◽  
Susan Fink ◽  
Katherine Forbush ◽  
Alexander Rudensky
Keyword(s):  
Cathepsin L ◽  
Specific Inhibitor ◽  
Cell Types ◽  
Interferon Γ ◽  
Cathepsin S ◽  
Antigen Presenting Cell ◽  
Relative Contribution ◽  
Helper Cell Type ◽  
Ifn Γ ◽  
Antigen Presenting

Cathepsin S (catS) and cathepsin L (catL) mediate late stages of invariant chain (Ii) degradation in discrete antigen-presenting cell types. Macrophages (Mϕs) are unique in that they express both proteases and here we sought to determine the relative contribution of each enzyme. We observe that catL plays no significant role in Ii cleavage in interferon (IFN)-γ–stimulated Mϕs. In addition, our studies show that the level of catL activity is significantly decreased in Mϕs cultured in the presence of IFN-γ whereas catS activity increases. The decrease in catL activity upon cytokine treatment occurs despite the persistence of high levels of mature catL protein, suggesting that a specific inhibitor of the enzyme is up-regulated in IFN-γ–stimulated peritoneal Mϕs. Similar inhibition of activity is observed in dendritic cells engineered to overexpress catL. Such enzymatic inhibition in Mϕs exhibits only partial dependence upon Ii and therefore, other mechanisms of catL inhibition are regulated by IFN-γ. Thus, during a T helper cell type 1 immune response catL inhibition in Mϕs results in preferential usage of catS, such that major histocompatibility complex class II presentation by all bone marrow–derived antigen-presenting cell is regulated by catS.

scholarly journals Th2 Cytokine Modulates Herpesvirus Reactivation in a Cell Type Specific Manner

2021 ◽  
Author(s):  
Guoxun Wang ◽  
Christina Zarek ◽  
Tyron Chang ◽  
Lili Tao ◽  
Alexandria Lowe ◽  
...  
Keyword(s):  
B Cells ◽  
Cell Types ◽  
The Body ◽  
Receptor Expression ◽  
Conditional Knockout ◽  
Interleukin 4 ◽  
Virus Reactivation ◽  
Cell Type ◽  
Murine Gammaherpesvirus ◽  
Cell Type Specific

Gammaherpesviruses, such as Epstein-Barr virus (EBV), Kaposi’s sarcoma associated virus (KSHV), and murine γ-herpesvirus 68 (MHV68), establish latent infection in B cells, macrophages, and non-lymphoid cells, and can induce both lymphoid and non-lymphoid cancers. Research on these viruses has relied heavily on immortalized B cell and endothelial cell lines. Therefore, we know very little about the cell type specific regulation of virus infection. We have previously shown that treatment of MHV68-infected macrophages with the cytokine interleukin-4 (IL-4) or challenge of MHV68-infected mice with an IL-4-inducing parasite leads to virus reactivation. However, we do not know if all latent reservoirs of the virus, including B cells, reactivate the virus in response to IL-4. Here we used an in vivo approach to address the question of whether all latently infected cell types reactivate MHV68 in response to a particular stimulus. We found that IL-4 receptor expression on macrophages was required for IL-4 to induce virus reactivation, but that it was dispensable on B cells. We further demonstrated that the transcription factor, STAT6, which is downstream of the IL-4 receptor and binds virus gene 50 N4/N5 promoter in macrophages, did not bind to the virus gene 50 N4/N5 promoter in B cells. These data suggest that stimuli that promote herpesvirus reactivation may only affect latent virus in particular cell types, but not in others. Importance Herpesviruses establish life-long quiescent infections in specific cells in the body, and only reactivate to produce infectious virus when precise signals induce them to do so. The signals that induce herpesvirus reactivation are often studied only in one particular cell type infected with the virus. However, herpesviruses establish latency in multiple cell types in their hosts. Using murine gammaherpesvirus-68 (MHV68) and conditional knockout mice, we examined the cell type specificity of a particular reactivation signal, interleukin-4 (IL-4). We found that IL-4 only induced herpesvirus reactivation from macrophages, but not from B cells. This work indicates that regulation of virus latency and reactivation is cell type specific. This has important implications for therapies aimed at either promoting or inhibiting reactivation for the control or elimination of chronic viral infections.

scholarly journals Epigenetic mechanisms mediating cell state transitions in chondrocytes

2020 ◽  
Author(s):  
Manuela Wuelling ◽  
Christoph Neu ◽  
Andrea M. Thiesen ◽  
Simo Kitanovski ◽  
Yingying Cao ◽  
...  
Keyword(s):  
Metabolic Pathways ◽  
Cell Lineage ◽  
Cell Types ◽  
State Transitions ◽  
Epigenetic Mechanisms ◽  
Cell Type ◽  
Transition Analysis ◽  
Lineage Differentiation ◽  
A Cell ◽  
Cell Type Specific

AbstractEpigenetic modifications play critical roles in regulating cell lineage differentiation, but the epigenetic mechanisms guiding specific differentiation steps within a cell lineage have rarely been investigated. To decipher such mechanisms, we used the defined transition from proliferating (PC) into hypertrophic chondrocytes (HC) during endochondral ossification as a model. We established a map of activating and repressive histone modifications for each cell type. ChromHMM state transition analysis and Pareto-based integration of differential levels of mRNA and epigenetic marks revealed that differentiation associated gene repression is initiated by the addition of H3K27me3 to promoters still carrying substantial levels of activating marks. Moreover, the integrative analysis identified genes specifically expressed in cells undergoing the transition into hypertrophy.Investigation of enhancer profiles detected surprising differences in enhancer number, location, and transcription factor binding sites between the two closely related cell types. Furthermore, cell type-specific upregulation of gene expression was associated with a shift from low to high H3K27ac decoration. Pathway analysis identified PC-specific enhancers associated with chondrogenic genes, while HC-specific enhancers mainly control metabolic pathways linking epigenetic signature to biological functions.

scholarly journals Neural stem cells induce the formation of their physical niche during organogenesis

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Ali Seleit ◽  
Isabel Krämer ◽  
Bea F Riebesehl ◽  
Elizabeth M Ambrosio ◽  
Julian S Stolper ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cell Lineage ◽  
Cell Types ◽  
Neural Lineage ◽  
Posterior Lateral Line ◽  
4D Imaging ◽  
Outer Border ◽  
Embryonic Life ◽  
Independent Life ◽  
Necessary And Sufficient

Most organs rely on stem cells to maintain homeostasis during post-embryonic life. Typically, stem cells of independent lineages work coordinately within mature organs to ensure proper ratios of cell types. Little is known, however, on how these different stem cells locate to forming organs during development. Here we show that neuromasts of the posterior lateral line in medaka are composed of two independent life-long lineages with different embryonic origins. Clonal analysis and 4D imaging revealed a hierarchical organisation with instructing and responding roles: an inner, neural lineage induces the formation of an outer, border cell lineage (nBC) from the skin epithelium. Our results demonstrate that the neural lineage is necessary and sufficient to generate nBCs highlighting self-organisation principles at the level of the entire embryo. We hypothesise that induction of surrounding tissues plays a major role during the establishment of vertebrate stem cell niches.

scholarly journals From spiral cleavage to bilateral symmetry: The developmental cell lineage of the annelid brain

2018 ◽  
Author(s):  
Pavel Vopalensky ◽  
Maria Antonietta Tosches ◽  
Kaia Achim ◽  
Mette Handberg-Thorsager ◽  
Detlev Arendt
Keyword(s):  
Nervous System ◽  
Marine Invertebrates ◽  
Rotational Symmetry ◽  
Cell Lineage ◽  
Bilateral Symmetry ◽  
Cell Types ◽  
Spiral Cleavage ◽  
Larval Brain ◽  
Larval Stages ◽  
Extensive Cell

AbstractThe spiral cleavage pattern is characteristic for Spiralia (Lophotrochozoa), a large assembly of marine invertebrates. In most cases, spiral cleavage produces freely swimming, trochophora-type larvae with a simple nervous system that controls ciliary locomotion. These larvae acquire bilateral symmetry, as manifested for example in the larval brain. The transition from the rotational symmetry of spiral cleavage into the bilateral adult body has not yet been understood. Here, we present the developmental cell lineage of the brain of the annelid Platynereis dumerilii from the zygote until the mid-trochophore stage (~30 hpf), in combination with a gene expression atlas for several embryonic and larval stages. Comparison of multiple embryos reveals a highly stereotypical development and an invariant cell lineage of the differentiated cell types. In addition, we observe a fundamental subdivision of the larval brain into a highly proliferative dorsolateral region and an early differentiating ventromedial region that gives rise to the apical nervous system. The transition from rotational to bilateral symmetry progresses gradually from the lateral to the central regions. Strikingly, the spiral-to-bilateral transition does not involve extensive cell migration. Rather, corresponding cells in different spiral quadrants acquire highly divergent identities in line with their bilateral position.

scholarly journals Neural stem cells induce the formation of their physical niche during organogenesis

2017 ◽  
Author(s):  
Ali Seleit ◽  
Isabel Krämer ◽  
Bea Riebesehl ◽  
Elizabeth M. Ambrosio ◽  
Julian S. Stolper ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cell Lineage ◽  
Cell Types ◽  
Neural Lineage ◽  
Posterior Lateral Line ◽  
4D Imaging ◽  
Outer Border ◽  
Embryonic Life ◽  
Independent Life ◽  
Necessary And Sufficient

AbstractMost organs rely on stem cells to maintain homeostasis during post-embryonic life. Typically, stem cells of independent lineages work coordinately within mature organs to ensure proper ratios of cell types. Little is known, however, on how these different stem cells locate to forming organs during development. Here we show that neuromasts of the posterior lateral line in medaka are composed of two independent life-long lineages with different embryonic origins. Clonal analysis and 4D imaging revealed a hierarchical organisation with instructing and responding roles: an inner, neural lineage induces the formation of an outer, border cell lineage (nBC) from the skin epithelium. Our results demonstrate that the neural lineage is necessary and sufficient to generate nBCs highlighting self-organisation principles at the level of the entire embryo. We hypothesise that transformation of surrounding tissues plays a major role during the establishment of vertebrate stem cell niches.

scholarly journals Predicting CTCF-mediated chromatin interactions by integrating genomic and epigenomic features

2017 ◽  
Author(s):  
Yan Kai ◽  
Jaclyn Andricovich ◽  
Zhouhao Zeng ◽  
Jun Zhu ◽  
Alexandros Tzatsos ◽  
...  
Keyword(s):  
Gene Expression ◽  
Long Range ◽  
Zinc Finger Protein ◽  
Cell Types ◽  
Learning Framework ◽  
Chromatin Interactions ◽  
Long Range Interactions ◽  
Extensive Cell ◽  
Cell Type Specific ◽  
And Function

AbstractThe CCCTC-binding zinc finger protein (CTCF)-mediated network of long-range chromatin interactions is important for genome organization and function. Although this network has been considered largely invariant, we found that it exhibits extensive cell-type-specific interactions that contribute to cell identity. Here we present Lollipop—a machine-learning framework—which predicts CTCF-mediated long-range interactions using genomic and epigenomic features. Using ChIA-PET data as benchmark, we demonstrated that Lollipop accurately predicts CTCF-mediated chromatin interactions both within and across cell-types, and outperforms other methods based only on CTCF motif orientation. Predictions were confirmed computationally and experimentally by Chromatin Conformation Capture (3C). Moreover, our approach reveals novel determinants of CTCF-mediated chromatin wiring, such as gene expression within the loops. Our study contributes to a better understanding about the underlying principles of CTCF-mediated chromatin interactions and their impact on gene expression.

scholarly journals Control of T helper cell differentiation through cytokine receptor inclusion in the immunological synapse

2009 ◽  
Vol 206 (4) ◽  
pp. 877-892 ◽  
Author(s):  
Roberto A. Maldonado ◽  
Michelle A. Soriano ◽  
L. Carolina Perdomo ◽  
Kirsten Sigrist ◽  
Darrell J. Irvine ◽  
...  
Keyword(s):  
Immunological Synapse ◽  
Nuclear Translocation ◽  
Interferon Γ ◽  
Membrane Receptors ◽  
Interleukin 4 ◽  
T Helper ◽  
Tcr Signaling ◽  
Effector Cells ◽  
Antigen Presenting ◽  
Th2 Differentiation

The antigen recognition interface formed by T helper precursors (Thps) and antigen-presenting cells (APCs), called the immunological synapse (IS), includes receptors and signaling molecules necessary for Thp activation and differentiation. We have recently shown that recruitment of the interferon-γ receptor (IFNGR) into the IS correlates with the capacity of Thps to differentiate into Th1 effector cells, an event regulated by signaling through the functionally opposing receptor to interleukin-4 (IL4R). Here, we show that, similar to IFN-γ ligation, TCR stimuli induce the translocation of signal transducer and activator of transcription 1 (STAT1) to IFNGR1-rich regions of the membrane. Unexpectedly, STAT1 is preferentially expressed, is constitutively serine (727) phosphorylated in Thp, and is recruited to the IS and the nucleus upon TCR signaling. IL4R engagement controls this process by interfering with both STAT1 recruitment and nuclear translocation. We also show that in cells with deficient Th1 or constitutive Th2 differentiation, the IL4R is recruited to the IS. This observation suggest that the IL4R is retained outside the IS, similar to the exclusion of IFNGR from the IS during IL4R signaling. This study provides new mechanistic cues for the regulation of lineage commitment by mutual immobilization of functionally antagonistic membrane receptors.

scholarly journals Lack of Foxp3 function and expression in the thymic epithelium

2007 ◽  
Vol 204 (3) ◽  
pp. 475-480 ◽  
Author(s):  
Adrian Liston ◽  
Andrew G. Farr ◽  
Zhibin Chen ◽  
Christophe Benoist ◽  
Diane Mathis ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Differentiation ◽  
T Cell ◽  
Epithelial Cells ◽  
Cell Population ◽  
Cell Lineage ◽  
Thymic Epithelial Cells ◽  
Thymic Epithelium ◽  
Thymocyte Differentiation ◽  
Necessary And Sufficient

Foxp3 is essential for the commitment of differentiating thymocytes to the regulatory CD4+ T (T reg) cell lineage. In humans and mice with a genetic Foxp3 deficiency, absence of this critical T reg cell population was suggested to be responsible for the severe autoimmune lesions. Recently, it has been proposed that in addition to T reg cells, Foxp3 is also expressed in thymic epithelial cells where it is involved in regulation of early thymocyte differentiation and is required to prevent autoimmunity. Here, we used genetic tools to demonstrate that the thymic epithelium does not express Foxp3. Furthermore, we formally showed that genetic abatement of Foxp3 in the hematopoietic compartment, i.e. in T cells, is both necessary and sufficient to induce the autoimmune lesions associated with Foxp3 loss. In contrast, deletion of a conditional Foxp3 allele in thymic epithelial cells did not result in detectable changes in thymocyte differentiation or pathology. Therefore, in mice the only known role for Foxp3 remains promotion of T reg cell differentiation within the T cell lineage, whereas there is no role for Foxp3 in thymic epithelial cells.

Analysis of R-Ras signalling pathways

2001 ◽  
Vol 114 (7) ◽  
pp. 1357-1366 ◽  
Author(s):  
A.J. Self ◽  
E. Caron ◽  
H.F. Paterson ◽  
A. Hall
Keyword(s):  
Map Kinase ◽  
Cell Cycle Progression ◽  
Cell Types ◽  
Small Gtpase ◽  
Signalling Pathways ◽  
Extensive Cell ◽  
Cell Type Specific ◽  
High Degree ◽  
Map Kinase Pathways ◽  
Ras Signalling

R-Ras has a high degree of sequence homology to Ras and to other members of the Ras subfamily including Rap, TC21 and M-Ras. Activated versions of Ras and TC21 are highly transforming in a variety of cell lines and mutated forms of both proteins have been found in human tumours. R-Ras interacts with many of the same proteins as Ras and TC21, including c-Raf1, and can induce transformed foci, although this activity is weak compared to Ras and appears to be cell-type specific. Here, we have investigated R-Ras signalling pathways in a variety of cell types. We find that microinjection of activated R-Ras into quiescent fibroblasts stimulates cell cycle progression through G(1) phase and subsequent DNA synthesis. However, unlike Ras, R-Ras does not activate the ERK MAP kinase pathway nor does it activate the JNK or p38/Mpk2 MAP kinase pathways. Microinjection of R-Ras into PC12 cells does not induce terminal differentiation, but instead causes extensive cell spreading, consistent with R-Ras having a role in integrin activation. Finally, in a macrophage cell line, R-Ras activates the (α)(M)(β)(2)integrin via the small GTPase Rap1, leading to phagocytosis of opsonized red blood cells, whereas Ras does not. These results indicate that R-Ras has an important role in the regulation of cell growth and adhesion, but that this is mediated through downstream signals distinct from those used by Ras.

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