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Gangopadhyay K, Roy S, Sen Gupta S, Chandradasan A, Chowdhury S, Das R. Regulating the discriminatory response to antigen by T-cell receptor. Biosci Rep 2022; 42:BSR20212012. [PMID: 35260878 PMCID: PMC8965820 DOI: 10.1042/bsr20212012] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 03/04/2022] [Accepted: 03/08/2022] [Indexed: 11/17/2022] Open
Abstract
The cell-mediated immune response constitutes a robust host defense mechanism to eliminate pathogens and oncogenic cells. T cells play a central role in such a defense mechanism and creating memories to prevent any potential infection. T cell recognizes foreign antigen by its surface receptors when presented through antigen-presenting cells (APCs) and calibrates its cellular response by a network of intracellular signaling events. Activation of T-cell receptor (TCR) leads to changes in gene expression and metabolic networks regulating cell development, proliferation, and migration. TCR does not possess any catalytic activity, and the signaling initiates with the colocalization of several enzymes and scaffold proteins. Deregulation of T cell signaling is often linked to autoimmune disorders like severe combined immunodeficiency (SCID), rheumatoid arthritis, and multiple sclerosis. The TCR remarkably distinguishes the minor difference between self and non-self antigen through a kinetic proofreading mechanism. The output of TCR signaling is determined by the half-life of the receptor antigen complex and the time taken to recruit and activate the downstream enzymes. A longer half-life of a non-self antigen receptor complex could initiate downstream signaling by activating associated enzymes. Whereas, the short-lived, self-peptide receptor complex disassembles before the downstream enzymes are activated. Activation of TCR rewires the cellular metabolic response to aerobic glycolysis from oxidative phosphorylation. How does the early event in the TCR signaling cross-talk with the cellular metabolism is an open question. In this review, we have discussed the recent developments in understanding the regulation of TCR signaling, and then we reviewed the emerging role of metabolism in regulating T cell function.
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Affiliation(s)
- Kaustav Gangopadhyay
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur campus, Mohanpur 741246, India
| | - Swarnendu Roy
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur campus, Mohanpur 741246, India
| | - Soumee Sen Gupta
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur campus, Mohanpur 741246, India
| | - Athira C. Chandradasan
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur campus, Mohanpur 741246, India
| | - Subhankar Chowdhury
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur campus, Mohanpur 741246, India
| | - Rahul Das
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur campus, Mohanpur 741246, India
- Centre for Advanced Functional Materials, Indian Institute of Science Education and Research Kolkata, Mohanpur campus, Mohanpur 741246, India
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Kim MS, Park D, Lee S, Park S, Kim KE, Kim TS, Park HJ, Cho D. Erythroid Differentiation Regulator 1 Strengthens TCR Signaling by Enhancing PLCγ1 Signal Transduction Pathway. Int J Mol Sci 2022; 23:ijms23020844. [PMID: 35055028 PMCID: PMC8776247 DOI: 10.3390/ijms23020844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 12/27/2021] [Accepted: 01/11/2022] [Indexed: 02/05/2023] Open
Abstract
Erythroid differentiation regulator 1 (Erdr1) has previously been reported to control thymocyte selection via TCR signal regulation, but the effect of Erdr1 as a TCR signaling modulator was not studied in peripheral T cells. In this report, it was determined whether Erdr1 affected TCR signaling strength in CD4 T cells. Results revealed that Erdr1 significantly enhanced the anti-TCR antibody-mediated activation and proliferation of T cells while failing to activate T cells in the absence of TCR stimulation. In addition, Erdr1 amplified Ca2+ influx and the phosphorylation of PLCγ1 in CD4 T cells with the TCR stimuli. Furthermore, NFAT1 translocation into nuclei in CD4 T cells was also significantly promoted by Erdr1 in the presence of TCR stimulation. Taken together, our results indicate that Erdr1 positively modulates TCR signaling strength via enhancing the PLCγ1/Ca2+/NFAT1 signal transduction pathway.
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Affiliation(s)
- Myun Soo Kim
- Kine Sciences, 525, Seolleung-ro, Gangnam-gu, Seoul 06149, Korea; (M.S.K.); (D.P.); (S.L.); (S.P.); (H.J.P.)
| | - Dongmin Park
- Kine Sciences, 525, Seolleung-ro, Gangnam-gu, Seoul 06149, Korea; (M.S.K.); (D.P.); (S.L.); (S.P.); (H.J.P.)
| | - Sora Lee
- Kine Sciences, 525, Seolleung-ro, Gangnam-gu, Seoul 06149, Korea; (M.S.K.); (D.P.); (S.L.); (S.P.); (H.J.P.)
| | - Sunyoung Park
- Kine Sciences, 525, Seolleung-ro, Gangnam-gu, Seoul 06149, Korea; (M.S.K.); (D.P.); (S.L.); (S.P.); (H.J.P.)
| | - Kyung Eun Kim
- Department of Cosmetic Sciences, Sookmyung Women’s University, Cheongpa-ro 47-gil 100 (Cheongpa-dong 2ga), Yongsan-gu, Seoul 04310, Korea;
| | - Tae Sung Kim
- Division of Life Sciences, College of Life Sciences and Biotechnology, Korea University, 5-ga, Anam-dong, Seongbuk-gu, Seoul 02841, Korea;
| | - Hyun Jeong Park
- Kine Sciences, 525, Seolleung-ro, Gangnam-gu, Seoul 06149, Korea; (M.S.K.); (D.P.); (S.L.); (S.P.); (H.J.P.)
| | - Daeho Cho
- Kine Sciences, 525, Seolleung-ro, Gangnam-gu, Seoul 06149, Korea; (M.S.K.); (D.P.); (S.L.); (S.P.); (H.J.P.)
- Institute of Convergence Science, Korea University, Anam-ro 145, Seongbuk-gu, Seoul 02841, Korea
- Correspondence: ; Tel.: +82-2-3290-3739; Fax: +82-2-928-8273
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An allosteric hot spot in the tandem-SH2 domain of ZAP-70 regulates T-cell signaling. Biochem J 2020; 477:1287-1308. [PMID: 32203568 DOI: 10.1042/bcj20190879] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 03/18/2020] [Accepted: 03/23/2020] [Indexed: 12/28/2022]
Abstract
T-cell receptor (TCR) signaling is initiated by recruiting ZAP-70 to the cytosolic part of TCR. ZAP-70, a non-receptor tyrosine kinase, is composed of an N-terminal tandem SH2 (tSH2) domain connected to the C-terminal kinase domain. The ZAP-70 is recruited to the membrane through binding of tSH2 domain and the doubly phosphorylated ITAM motifs of CD3 chains in the TCR complex. Our results show that the tSH2 domain undergoes a biphasic structural transition while binding to the doubly phosphorylated ITAM-ζ1 peptide. The C-terminal SH2 domain binds first to the phosphotyrosine residue of ITAM peptide to form an encounter complex leading to subsequent binding of second phosphotyrosine residue to the N-SH2 domain. We decipher a network of noncovalent interactions that allosterically couple the two SH2 domains during binding to doubly phosphorylated ITAMs. Mutation in the allosteric network residues, for example, W165C, uncouples the formation of encounter complex to the subsequent ITAM binding thus explaining the altered recruitment of ZAP-70 to the plasma membrane causing autoimmune arthritis in mice. The proposed mechanism of allosteric coupling is unique to ZAP-70, which is fundamentally different from Syk, a close homolog of ZAP-70 expressed in B-cells.
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Zhou XX, Bracken CJ, Zhang K, Zhou J, Mou Y, Wang L, Cheng Y, Leung KK, Wells JA. Targeting Phosphotyrosine in Native Proteins with Conditional, Bispecific Antibody Traps. J Am Chem Soc 2020; 142:17703-17713. [PMID: 32924468 DOI: 10.1021/jacs.0c08458] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Engineering sequence-specific antibodies (Abs) against phosphotyrosine (pY) motifs embedded in folded polypeptides remains highly challenging because of the stringent requirement for simultaneous recognition of the pY motif and the surrounding folded protein epitope. Here, we present a method named phosphotyrosine Targeting by Recombinant Ab Pair, or pY-TRAP, for in vitro engineering of binders for native pY proteins. Specifically, we create the pY protein by unnatural amino acid misincorporation, mutagenize a universal pY-binding Ab to create a first binder B1 for the pY motif on the pY protein, and then select against the B1-pY protein complex for a second binder B2 that recognizes the composite epitope of B1 and the pY-containing protein complex. We applied pY-TRAP to create highly specific binders to folded Ub-pY59, a rarely studied Ub phosphoform exclusively observed in cancerous tissues, and ZAP70-pY248, a kinase phosphoform regulated in feedback signaling pathways in T cells. The pY-TRAPs do not have detectable binding to wild-type proteins or to other pY peptides or proteins tested. This pY-TRAP approach serves as a generalizable method for engineering sequence-specific Ab binders to native pY proteins.
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Affiliation(s)
- Xin X Zhou
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94158, United States
| | - Colton J Bracken
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94158, United States
| | - Kaihua Zhang
- Department of Biochemistry and Biophysics, University of California, San Francisco, California 94158, United States
| | - Jie Zhou
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94158, United States
| | - Yun Mou
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94158, United States
| | - Lei Wang
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94158, United States
| | - Yifan Cheng
- Department of Biochemistry and Biophysics, University of California, San Francisco, California 94158, United States.,Howard Hughes Medical Institute, University of California, San Francisco, California 94158, United States
| | - Kevin K Leung
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94158, United States
| | - James A Wells
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94158, United States.,Chan Zuckerberg Biohub, San Francisco, California 94158, United States.,Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California 94158, United States
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Alatoom A, Sapudom J, Soni P, Mohamed WKE, Garcia-Sabaté A, Teo J. Artificial Biosystem for Modulation of Interactions between Antigen-Presenting Cells and T Cells. ACTA ACUST UNITED AC 2020; 4:e2000039. [PMID: 32453495 DOI: 10.1002/adbi.202000039] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 05/08/2020] [Indexed: 12/12/2022]
Abstract
T cell activation is triggered by signal molecules on the surface of antigen-presenting cells (APC) and subsequent exertion of cellular forces. Deciphering the biomechanical and biochemical signals in this complex process is of interest and will contribute to an improvement in immunotherapy strategies. To address underlying questions, coculture and biomimetic models are established. Mature dendritic cells (mDC) are first treated with cytochalasin B (CytoB), a cytoskeletal disruption agent known to lower apparent cellular stiffness and reduction in T cell proliferation is observed. It is attempted to mimic mDC and T cell interactions using polyacrylamide (PA) gels with defined stiffness corresponding to mDC (0.2-25 kPa). Different ratios of anti-CD3 (aCD3) and anti-CD28 (aCD28) antibodies are immobilized onto PA gels. The results show T cell proliferation is triggered by both aCD3 and aCD28 in a stiffness-dependent manner. Cells cultured on aCD3 immobilized on gels has significantly enhanced proliferation and IL-2 secretion, compared to aCD28. Furthermore, ZAP70 phosphorylation is enhanced in stiffer substrate a in a aCD3-dependent manner. The biosystem provides an approach to study the reduction of T cell proliferation observed on CytoB-treated mDC. Overall, the biosystem allows distinguishing the impact of biophysical and biochemical signals of APC and T cell interactions in vitro.
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Affiliation(s)
- Aseel Alatoom
- Laboratory for Immuno Bioengineering Research and Applications, Division of Engineering, New York University Abu Dhabi, Abu Dhabi, UAE
| | - Jiranuwat Sapudom
- Laboratory for Immuno Bioengineering Research and Applications, Division of Engineering, New York University Abu Dhabi, Abu Dhabi, UAE
| | - Priya Soni
- Laboratory for Immuno Bioengineering Research and Applications, Division of Engineering, New York University Abu Dhabi, Abu Dhabi, UAE
| | - Walaa Kamal E Mohamed
- Laboratory for Immuno Bioengineering Research and Applications, Division of Engineering, New York University Abu Dhabi, Abu Dhabi, UAE
| | - Anna Garcia-Sabaté
- Laboratory for Immuno Bioengineering Research and Applications, Division of Engineering, New York University Abu Dhabi, Abu Dhabi, UAE
| | - Jeremy Teo
- Laboratory for Immuno Bioengineering Research and Applications, Division of Engineering, New York University Abu Dhabi, Abu Dhabi, UAE.,Department of Mechanical Engineering, Tandon School of Engineering New York University, USA.,Department of Biomedical Engineering, Tandon School of Engineering New York University, USA
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Intensity and duration of TCR signaling is limited by p38 phosphorylation of ZAP-70 T293 and destabilization of the signalosome. Proc Natl Acad Sci U S A 2018; 115:2174-2179. [PMID: 29440413 DOI: 10.1073/pnas.1713301115] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
ZAP-70 is a tyrosine kinase that is essential for initiation of T cell antigen receptor (TCR) signaling. We have found that T cell p38 MAP kinase (MAPK), which is directly phosphorylated and activated by ZAP-70 downstream of the TCR, in turn phosphorylates Thr-293 in the interdomain B region of ZAP-70. Mutant T cells expressing ZAP-70 with an alanine substitution at this residue (ZAP-70T293A) had enhanced TCR proximal signaling and increased effector responses. Lack of ZAP-70T293 phosphorylation increased association of ZAP-70 with the TCR and prolonged the existence of TCR signaling microclusters. These results identify a tight negative feedback loop in which ZAP-70-activated p38 reciprocally phosphorylates ZAP-70 and destabilizes the signaling complex.
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A cycle of Zap70 kinase activation and release from the TCR amplifies and disperses antigenic stimuli. Nat Immunol 2016; 18:86-95. [PMID: 27869819 PMCID: PMC5490839 DOI: 10.1038/ni.3631] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 10/28/2016] [Indexed: 12/14/2022]
Abstract
Cell-surface-receptor pathways amplify weak, rare and local stimuli to induce cellular responses. This task is accomplished despite signaling components that segregate into nanometer-scale membrane domains. Here we describe a 'catch-and-release' mechanism that amplified and dispersed stimuli by releasing activated kinases from receptors lacking intrinsic catalytic activity. Specifically, we discovered a cycle of recruitment, activation and release for Zap70 kinases at phosphorylated T cell antigen receptors (TCRs). This turned the TCR into a 'catalytic unit' that amplified antigenic stimuli. Zap70 released from the TCR remained at the membrane, translocated, and phosphorylated spatially distinct substrates. The mechanisms described here are based on widely used protein domains and post-translational modifications; therefore, many membrane-associated pathways might employ similar mechanisms for signal amplification and dispersion.
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8
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Increased PTPN22 expression and defective CREB activation impair regulatory T-cell differentiation in non-ST-segment elevation acute coronary syndromes. J Am Coll Cardiol 2015; 65:1175-1186. [PMID: 25814225 DOI: 10.1016/j.jacc.2015.01.027] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 01/07/2015] [Accepted: 01/14/2015] [Indexed: 01/08/2023]
Abstract
BACKGROUND Critical impairment of adaptive immune response has been observed in patients with acute coronary syndromes (ACS) with reduced expansion of regulatory T cells (Treg) and enhanced effector T-cell responsiveness, both associated with poorer outcomes. OBJECTIVES This study investigated the mechanisms underlying T-cell dysregulation in ACS. METHODS We evaluated both early and downstream T-cell receptor activation pathways after ex vivo stimulation with anti-CD3 and anti-CD28 crosslink in CD4(+) T cells from 20 patients with non-ST-segment elevation myocardial infarction (NSTEMI), 20 with stable angina (SA), and 20 controls. We reassessed 10 NSTEMI and 10 SA patients after 1 year. RESULTS Phospho-flow analysis revealed reduced phosphorylation of the zeta-chain-associated protein kinase of 70 kDa at the inhibitory residue tyrosine 292, enhancing T-cell activation, in NSTEMI helper T cells versus SA and controls (each, p < 0.001), resulting from increased expression of the protein tyrosine phosphatase, nonreceptor type, 22 (PTPN22) (p < 0.001 for both comparisons), persisting at follow-up. We also observed reduced phosphorylation (p < 0.001 versus controls) and lower levels of binding to interleukins 2 and 10 core promoter regions of the transcription factor cyclic adenosine monophosphate response element-binding protein (CREB) in NSTEMI (p < 0.05 vs. controls), which recovered at 1 year. Finally, in NSTEMI patients, helper T cells had a reduced ability in T-cell receptor-induced Treg generation (p = 0.002 vs. SA; p = 0.001 vs. controls), partially recovered at 1 year. Restoring CREB activity and silencing PTPN22 enhanced NSTEMI patients' ability to generate Treg. CONCLUSIONS The persistent overexpression of PTPN22 and the transient reduction of CREB activity, associated with impaired Treg differentiation, might play a role in ACS.
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9
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Resolving Early Signaling Events in T-Cell Activation Leading to IL-2 and FOXP3 Transcription. Processes (Basel) 2014. [DOI: 10.3390/pr2040867] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Dielschneider RF, Xiao W, Yoon JY, Noh E, Banerji V, Li H, Marshall AJ, Johnston JB, Gibson SB. Gefitinib targets ZAP-70-expressing chronic lymphocytic leukemia cells and inhibits B-cell receptor signaling. Cell Death Dis 2014; 5:e1439. [PMID: 25275600 PMCID: PMC4649506 DOI: 10.1038/cddis.2014.391] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 07/04/2014] [Accepted: 08/06/2014] [Indexed: 01/03/2023]
Abstract
Chronic lymphocytic leukemia (CLL) can be divided into groups based on biomarkers of poor prognosis. The expression of the tyrosine kinase ZAP-70 (member of the Syk tyrosine kinase family) in CLL cells is associated with shorter overall survival in CLL patients. Currently, there is a lack of targeted therapies for patients with ZAP-70 expression in CLL cells. The tyrosine kinase inhibitor gefitinib has been shown to be effective at induce apoptosis in acute myeloid leukemia through inhibition of Syk. In this study, we sought to test the efficacy of gefitinib in primary human ZAP-70+ CLL cells. We demonstrate that gefitinib preferentially induces cell death in ZAP-70-expressing CLL cells with a median IC50 of 4.5 μM. In addition, gefitinib decreases the viability of ZAP-70+ Jurkat T leukemia cells but fails to affect T cells from CLL patients. Western blot analysis shows gefitinib reduces both basal and B-cell receptor (BCR)-stimulated phosphorylation of Syk/ZAP-70, ERK, and Akt in ZAP-70+ CLL cells. Moreover, gefitinib inhibits the pro-survival response from BCR stimulation and decreases pro-survival proteins such as Mcl-1. Finally, ZAP-70 expression sensitizes Raji cells to gefitinib treatment. These results demonstrate that gefitinib specifically targets ZAP-70+ CLL cells and inhibits the BCR cell survival pathway leading to apoptosis. This represents the likelihood of tyrosine kinase inhibitors being effective targeted treatments for ZAP-70+ CLL cells.
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Affiliation(s)
- R F Dielschneider
- 1] Department of Immunology, University of Manitoba, Winnipeg, MB, Canada [2] Manitoba Institute of Cell Biology, Winnipeg, MB, Canada
| | - W Xiao
- Manitoba Institute of Cell Biology, Winnipeg, MB, Canada
| | - J-Y Yoon
- 1] Manitoba Institute of Cell Biology, Winnipeg, MB, Canada [2] Department of Internal Medicine, University of Manitoba, Winnipeg, MB, Canada
| | - E Noh
- Manitoba Institute of Cell Biology, Winnipeg, MB, Canada
| | - V Banerji
- 1] Manitoba Institute of Cell Biology, Winnipeg, MB, Canada [2] Department of Internal Medicine, University of Manitoba, Winnipeg, MB, Canada [3] Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB, Canada
| | - H Li
- Department of Immunology, University of Manitoba, Winnipeg, MB, Canada
| | - A J Marshall
- Department of Immunology, University of Manitoba, Winnipeg, MB, Canada
| | - J B Johnston
- 1] Manitoba Institute of Cell Biology, Winnipeg, MB, Canada [2] Department of Internal Medicine, University of Manitoba, Winnipeg, MB, Canada
| | - S B Gibson
- 1] Department of Immunology, University of Manitoba, Winnipeg, MB, Canada [2] Manitoba Institute of Cell Biology, Winnipeg, MB, Canada [3] Department of Internal Medicine, University of Manitoba, Winnipeg, MB, Canada [4] Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB, Canada
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Some findings of FADD knockdown in inhibition of HIV-1 replication in Jurkat cells and PBMCs. Mol Cell Biochem 2014; 393:181-90. [PMID: 24752353 DOI: 10.1007/s11010-014-2058-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 04/03/2014] [Indexed: 10/25/2022]
Abstract
Fas-associated protein with death domain (FADD) is a key adaptor molecule transmitting the death signal mediated by death receptors, and it is also required for T cell proliferation. A recent study indicated that FADD is able to affect HIV-1 production, but the mechanism is not known. Using the susceptible Jurkat cell line and peripheral blood mononuclear cells, we studied the effects of FADD on HIV-1 production. TaqMan RT-PCR was used to quantify HIV-1 viral RNA copies, and Western blot analysis was used to detect protein expression. FADD knockdown decreased HIV-1 replication and inactivated caspase-3 activity in the cells and blocked CD4 translocation to the lipid rafts of the plasma membrane. Reduced expression of FADD suppressed TCR signaling through downregulation of TCR, CD3, and Zap-70 in response to HIV-1 infection and blocked the trafficking of TCR, CD3, CD28, and Zap-70 to lipid rafts, leading to reduced activation of NF-κB and NFAT, which are required for HIV-1 replication. FADD knockdown diminished caspase-8 migration to lipid rafts and its expression in response to HIV-1 infection. These results indicate that FADD, as a host pro-apoptotic protein, plays important roles in regulating HIV-1 replication and production in several ways, and apoptotic pathway inhibition is able to decrease HIV-1 replication and production.
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ZAP-70 tyrosines 315 and 492 transmit non-genomic glucocorticoid (GC) effects in T cells. Mol Immunol 2013; 53:111-7. [DOI: 10.1016/j.molimm.2012.07.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Revised: 07/20/2012] [Accepted: 07/21/2012] [Indexed: 01/16/2023]
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