scholarly journals E-protein–regulated expression of CXCR4 adheres preselection thymocytes to the thymic cortex

2019 ◽  
Vol 216 (8) ◽  
pp. 1749-1761 ◽  
Author(s):  
Tejas Kadakia ◽  
Xuguang Tai ◽  
Michael Kruhlak ◽  
Jan Wisniewski ◽  
Il-Young Hwang ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Chemokine Receptor ◽  
Chemokine Receptors ◽  
Cxcr4 Expression ◽  
Receptor Expression ◽  
Thymic Epithelial Cells ◽  
E Protein ◽  
Regulated Expression ◽  
Genes Encoding ◽  
Protein Transcription

Preselection thymocytes are normally retained in the thymic cortex, but the mechanisms responsible remain incompletely understood. We now report that deletion of genes encoding the E-protein transcription factors E2A and HEB disorders chemokine receptor expression on developing thymocytes to allow escape of preselection TCR−CD8+ thymocytes into the periphery. We document that CXCR4 expression normally anchors preselection thymocytes to the thymic cortex via interaction with its ligand CXCL12 on cortical thymic epithelial cells, and that disruption of CXCR4–CXCL12 engagements release preselection thymocytes from the thymic cortex. We further document that CXCR4 expression must be extinguished by TCR-mediated positive selection signals to allow migration of TCR-signaled thymocytes out of the thymic cortex into the medulla. Thus, E-protein transcription factors regulate the ordered expression pattern of chemokine receptors on developing thymocytes, and the interaction of the chemokine receptor CXCR4 with its ligand adheres TCR-unsignaled preselection thymocytes to the thymic cortex.

scholarly journals Biphasic Expression of Atypical Chemokine Receptor (ACKR) 2 and ACKR4 in Colorectal Neoplasms in Association with Histopathological Findings

Biomolecules ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 8
Author(s):  
Paulina Lewandowska ◽  
Jaroslaw Wierzbicki ◽  
Marek Zawadzki ◽  
Anil Agrawal ◽  
Małgorzata Krzystek-Korpacka
Keyword(s):  
Lymph Node ◽  
Lymph Node Metastasis ◽  
Chemokine Receptor ◽  
Growth Pattern ◽  
Chemokine Receptors ◽  
Receptor Expression ◽  
Transcriptional Analysis ◽  
Neoplastic Tissue ◽  
Node Metastasis ◽  
Affected Tissue

Facilitating resolution of inflammation using atypical chemokine receptors (ACKR) as an anticancer strategy is considered but requires a deeper understanding of receptor role in carcinogenesis. We aimed at transcriptional analysis (RTqPCR) of ACKR2 and ACKR4 expression in colorectal adenoma-adenocarcinoma sequence in paired normal-neoplastic tissues from 96 polyps and 51 cancers. On average, ACKR2 was downregulated in neoplastic as compared to non-affected tissue in polyp (by 2.7-fold) and cancer (by 3.1-fold) patients. The maximal downregulation (by 8.2-fold) was observed in adenomas with the highest potential for malignancy and was gradually lessening through cancer stages I-IV, owing to increased receptor expression in tumors. On average, ACKR4 was significantly downregulated solely in adenocarcinomas (by 1.5-fold), less so in patients with lymph node metastasis, owing to a gradual decrease in ACKR4 expression among N0-N1-N2 cancers in non-affected tissue without changes in tumors. In adenomas, ACKR4 downregulation in neoplastic tissue increased with increasing potential for malignancy and contribution of villous growth pattern. ACKR4 expression increased in non-affected tissue with a concomitant decrease in pathological mucosa. In conclusion, the changes in ACKRs expression occur already in precancerous colorectal lesions, culminating in the adenomas with the highest potential for malignancy. Therefore, chemoprevention by manipulating ACKRs’ expression is worth exploration.

scholarly journals Chemokine and Chemokine Receptor Dynamics during Genital Chlamydial Infection

2002 ◽  
Vol 70 (2) ◽  
pp. 844-850 ◽  
Author(s):  
Tesfaye Belay ◽  
Francis O. Eko ◽  
Godwin A. Ananaba ◽  
Samera Bowers ◽  
Terri Moore ◽  
...  
Keyword(s):  
Chemokine Receptor ◽  
Chemokine Receptors ◽  
Primary Infection ◽  
Chlamydial Infection ◽  
Time Course ◽  
Secondary Infection ◽  
Receptor Expression ◽  
Microbial Pathogens ◽  
Intercellular Adhesion Molecule ◽  
Regulation Of Expression

ABSTRACT Current design strategies for vaccines against certain microbial pathogens, including Chlamydia trachomatis, require the induction and targeting of specific immune effectors to the local sites of infection known as the mucosal effector sites. Chemokines and their receptors are important mediators of leukocyte trafficking and of the controlled recruitment of specific leukocyte clonotypes during host defense against infections and during inflammation. We analyzed the dynamics of chemokine and chemokine receptor expression in genital mucosae during genital chlamydial infection in a murine model to determine how these molecular entities influence the development of immunity and the clearance of infection. A time course study revealed an increase of up to threefold in the levels of expression of RANTES, monocyte chemotactic protein 1 (MCP-1), gamma-interferon-inducible protein 10 (IP-10), macrophage inflammatory protein 1α (MIP-1α), and intercellular adhesion molecule type 1 (ICAM-1) after genital infection with the C. trachomatis agent of mouse pneumonitis. Peak levels of expression of RANTES, MCP-1, and MIP-1α occurred by day 7 after primary infection, while those of IP-10 and ICAM-1 peaked by day 21. Expression levels of these molecules decreased by day 42 after primary infection, by which time all animals had resolved the infection, suggesting an infection-driven regulation of expression. A rapid upregulation of expression of these molecules was observed after secondary infection. The presence of cells bearing the chemokine receptors CCR5 and CXCR3, known to be preferentially expressed on Th1 and dendritic cells, was also synchronous with the kinetics of immune induction in the genital tract and clearance of infection. Results demonstrated that genital chlamydial infection is associated with a significant induction of chemokines and chemokine receptors that are involved in the recruitment of Th1 cells into the site of infection. Future studies will focus on how selective modulation of chemokines and their receptors can be used to optimize long-term immunity against Chlamydia.

Neuropeptide substance P upregulates chemokine and chemokine receptor expression in primary mouse neutrophils

2007 ◽  
Vol 293 (2) ◽  
pp. C696-C704 ◽  
Author(s):  
Jia Sun ◽  
Raina Devi Ramnath ◽  
Madhav Bhatia
Keyword(s):  
Substance P ◽  
Chemokine Receptor ◽  
Chemokine Receptors ◽  
Binding Activity ◽  
Receptor Expression ◽  
Chemokine Production ◽  
Chemokine Receptor Expression ◽  
Cc Chemokine ◽  
Primary Mouse ◽  
Cxc Chemokine

Neuropeptides play an important role in the active communication between the nervous and immune systems. Substance P (SP) is a prominent neuropeptide involved in neurogenic inflammation and has been reported to exert various proinflammatory actions on inflammatory leukocytes including neutrophils. The present study further investigated the modulatory effect of SP (1 μM) on chemokine production and chemokine receptor expression in primary mouse neutrophils. Our results showed that SP primed neutrophils for chemotactic responses not only to the CXC chemokine macrophage inflammatory protein (MIP)-2/CXCL2 but also to the CC chemokine MIP-1α/CCL3. The activating effect of SP on neutrophils was further evidenced by upregulation of the CD11b integrin, the activation marker of neutrophils. SP induced both the mRNA and protein expression of the chemokines MIP-1α/CCL3 and MIP-2/CXCL2 in neutrophils and upregulated the chemokine receptors CC chemokine receptor (CCR)-1 and CXC chemokine receptor (CXCR)-2. This stimulatory effect on chemokine and chemokine receptor expression in neutrophils was further found to be neurokinin-1 receptor (NK-1R) specific. Pretreatment with selective NK-1R antagonists inhibited SP-triggered activation of neutrophils and chemokine and chemokine receptor upregulation. Moreover, SP-induced chemokine upregulation was NF-κB dependent. SP time dependently induced NF-κB p65 binding activity, IκBα degradation, and NF-κB p65 nuclear translocation in neutrophils. Inhibition of NF-κB activation with its inhibitor Bay11-7082 (10 μM) abolished SP-induced NF-κB binding activity and upregulation of MIP-1α/CCL3 and MIP-2/CXCL2 in neutrophils. Together, these results suggest that SP exerts a direct stimulatory effect on the expression of chemokines and chemokine receptors in mouse neutrophils. The effect is NK-1R mediated, involving NF-κB activation.

scholarly journals CD134 and CXCR4 expression corresponds to feline immunodeficiency virus infection of lymphocytes, macrophages and dendritic cells

2008 ◽  
Vol 89 (1) ◽  
pp. 277-287 ◽  
Author(s):  
F. Reggeti ◽  
C. Ackerley ◽  
D. Bienzle
Keyword(s):  
Dendritic Cells ◽  
Feline Immunodeficiency Virus ◽  
Chemokine Receptors ◽  
Cell Activation ◽  
Cxcr4 Expression ◽  
Receptor Expression ◽  
Subtype B ◽  
Feline Immunodeficiency Virus Infection ◽  
Immunodeficiency Virus ◽  
Gene Transcripts

The lymphotropic lentiviruses feline immunodeficiency virus (FIV) and human immunodeficiency virus (HIV) enter cells by sequential interaction with primary receptors CD134 or CD4, respectively, and subsequently with chemokine receptors. The host-cell range for FIV is broader than that for HIV, but whether this is a function of receptor expression is unknown. Lack of reagents specific to feline molecules has limited detection and analysis of receptors and their interaction with viral components. Here, the expression of CD134 and CXCR4 on feline T and B lymphocytes, dendritic cells (DCs) and macrophages was examined and the kinetics of FIV replication were assessed. Quantification of CD134 mRNA by real-time PCR indicated expression in all leukocytes, with significantly more transcripts in CD4+ lymphocytes than in other leukocytes. Antibodies against human CD134 bound inconsistently to feline leukocytes. CXCR4 was detected with antibody clone 12G5 on the surface of monocyte-derived cells only, but gene transcripts were present in all cells, with the highest copy number in lymphocytes. CXCR4 expression decreased and CD134 expression increased with cell activation in lymphocytes. A subtype B biological isolate of FIV infected DCs, macrophages and lymphocytes, with the highest replication in CD4+ lymphocytes, whilst cloned FIV P14 infected all cells, but replicated less efficiently. Although viral replication was lower in DCs and macrophages than in lymphocytes, DCs expressed specific receptors and were infected productively with FIV, as indicated by viral ultrastructure and DNA detection. These results may implicate altered function of DCs in the induction of specific immunity against FIV.

Coreceptor/Chemokine Receptor Expression on Human Hematopoietic Cells: Biological Implications for Human Immunodeficiency Virus–Type 1 Infection

Blood ◽  
1999 ◽  
Vol 93 (4) ◽  
pp. 1145-1156 ◽  
Author(s):  
Benhur Lee ◽  
Janina Ratajczak ◽  
Robert W. Doms ◽  
Alan M. Gewirtz ◽  
Mariusz Z. Ratajczak
Keyword(s):  
Chemokine Receptor ◽  
Chemokine Receptors ◽  
Hematopoietic Cells ◽  
Receptor Expression ◽  
Chemokine Receptor Expression ◽  
Cd34 Cells ◽  
Immunodeficiency Virus ◽  
Γ Interferon ◽  
Hiv 1

Abstract The recent discovery of chemokine receptors as coreceptors for human immunodeficiency virus–type 1 (HIV-1) entry offers new avenues for investigating the pathogenesis of acquired immunodeficiency syndrome (AIDS)-related cytopenias. To this end, we sought to (1) phenotype human hematopoietic cells for CD4 and the HIV-1 coreceptors CXCR4, CCR5, CCR3, and CCR2b; (2) correlate CD4 and chemokine receptor expression with their susceptibility to HIV-1 infection; and (3) examine any potential interplay between inflammatory cytokines released during HIV-1 infection and regulation of chemokine receptor expression. Fluorescence-activated cell sorting (FACS) analysis of bone marrow mononuclear cells (BMMNC), cells derived from serum-free expanded hematopoietic lineages (colony-forming unit–granulocyte-macrophage [CFU-GM], colony-forming unit-megakaryocyte [CFU-Meg], and burst-forming unit-erythroid [BFU-E]), and CD34+ cells showed differential expression of chemokine receptors and CD4 with some lineage specificity. Significantly, FACS-sorted CXCR4+/CD34+ cells had the same clonogeneic potential as CXCR4−/CD34+ cells. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of FACS-sorted human candidate stem cells (HSC; CD34+, c-kit+, Rho123low) showed the presence of CXCR4 mRNA but not CD4 mRNA. Infection studies with HIV-1 Env-pseudotyped luciferase reporter viruses indicated that X4 Env (CXCR4-using) pseudotypes infected megakaryocytic cells, whereas R5 Env (CCR5-using) pseudotypes did not. Similarly, R5 but not X4 Env-pseudotyped viruses infected granulocyte-macrophage cells in a CD4/CCR5-dependent manner. Erythroid cells were resistant to R5 or X4 viral infection. Finally, we found that γ-interferon treatment upregulated CXCR4 expression on primary hematopoietic cells. In summary, the delineation of chemokine receptor expression on primary hematopoietic cells is a first step towards dissecting the chemokine-chemokine receptor axes that may play a role in hematopoietic cell proliferation and homing. Furthermore, susceptibility of hematopoietic cells to HIV-1 infection is likely to be more complicated than the mere physical presence of CD4 and the cognate chemokine receptor. Lastly, our results suggest a potential interplay between γ-interferon secretion and CXCR4 expression.

Coreceptor/Chemokine Receptor Expression on Human Hematopoietic Cells: Biological Implications for Human Immunodeficiency Virus–Type 1 Infection

Blood ◽  
1999 ◽  
Vol 93 (4) ◽  
pp. 1145-1156 ◽  
Author(s):  
Benhur Lee ◽  
Janina Ratajczak ◽  
Robert W. Doms ◽  
Alan M. Gewirtz ◽  
Mariusz Z. Ratajczak
Keyword(s):  
Chemokine Receptor ◽  
Chemokine Receptors ◽  
Hematopoietic Cells ◽  
Receptor Expression ◽  
Chemokine Receptor Expression ◽  
Cd34 Cells ◽  
Immunodeficiency Virus ◽  
Γ Interferon ◽  
Hiv 1

The recent discovery of chemokine receptors as coreceptors for human immunodeficiency virus–type 1 (HIV-1) entry offers new avenues for investigating the pathogenesis of acquired immunodeficiency syndrome (AIDS)-related cytopenias. To this end, we sought to (1) phenotype human hematopoietic cells for CD4 and the HIV-1 coreceptors CXCR4, CCR5, CCR3, and CCR2b; (2) correlate CD4 and chemokine receptor expression with their susceptibility to HIV-1 infection; and (3) examine any potential interplay between inflammatory cytokines released during HIV-1 infection and regulation of chemokine receptor expression. Fluorescence-activated cell sorting (FACS) analysis of bone marrow mononuclear cells (BMMNC), cells derived from serum-free expanded hematopoietic lineages (colony-forming unit–granulocyte-macrophage [CFU-GM], colony-forming unit-megakaryocyte [CFU-Meg], and burst-forming unit-erythroid [BFU-E]), and CD34+ cells showed differential expression of chemokine receptors and CD4 with some lineage specificity. Significantly, FACS-sorted CXCR4+/CD34+ cells had the same clonogeneic potential as CXCR4−/CD34+ cells. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of FACS-sorted human candidate stem cells (HSC; CD34+, c-kit+, Rho123low) showed the presence of CXCR4 mRNA but not CD4 mRNA. Infection studies with HIV-1 Env-pseudotyped luciferase reporter viruses indicated that X4 Env (CXCR4-using) pseudotypes infected megakaryocytic cells, whereas R5 Env (CCR5-using) pseudotypes did not. Similarly, R5 but not X4 Env-pseudotyped viruses infected granulocyte-macrophage cells in a CD4/CCR5-dependent manner. Erythroid cells were resistant to R5 or X4 viral infection. Finally, we found that γ-interferon treatment upregulated CXCR4 expression on primary hematopoietic cells. In summary, the delineation of chemokine receptor expression on primary hematopoietic cells is a first step towards dissecting the chemokine-chemokine receptor axes that may play a role in hematopoietic cell proliferation and homing. Furthermore, susceptibility of hematopoietic cells to HIV-1 infection is likely to be more complicated than the mere physical presence of CD4 and the cognate chemokine receptor. Lastly, our results suggest a potential interplay between γ-interferon secretion and CXCR4 expression.

Chemokine receptors and their role in inflammation and infectious diseases

Blood ◽  
2000 ◽  
Vol 95 (10) ◽  
pp. 3032-3043 ◽  
Author(s):  
Craig Murdoch ◽  
Adam Finn
Keyword(s):  
Infectious Diseases ◽  
Chemokine Receptor ◽  
Intracellular Signaling ◽  
Chemokine Receptors ◽  
Cell Activation ◽  
Cell Types ◽  
Receptor Expression ◽  
Chemokine Receptor Expression ◽  
Disease States ◽  
Receptor Biology

Chemokines are small peptides that are potent activators and chemoattractants for leukocyte subpopulations and some nonhemopoietic cells. Their actions are mediated by a family of 7-transmembrane G-protein–coupled receptors, the size of which has grown considerably in recent years and now includes 18 members. Chemokine receptor expression on different cell types and their binding and response to specific chemokines are highly variable. Significant advances have been made in understanding the regulation of chemokine receptor expression and the intracellular signaling mechanisms used in bringing about cell activation. Chemokine receptors have also recently been implicated in several disease states including allergy, psoriasis, atherosclerosis, and malaria. However, most fascinating has been the observation that some of these receptors are used by human immunodeficiency virus type 1 in gaining entry into permissive cells. This review will discuss structural and functional aspects of chemokine receptor biology and will consider the roles these receptors play in inflammation and in infectious diseases.

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