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Zhilinskaia IN, Maklakova AS, Ashmarin IP. [Influence of isolated virion proteins of hepatitis A virus on the behavior of rats]. Vopr Virusol 2004; 49:26-8. [PMID: 15529860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
Influenza A virus M-proteins can cause depression in experimental animals 1 day after administration. HA and NA, on the contrary, activate motor activity in animals under the similar conditions. The effect of viral proteins is dose-dependent.
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Tao YG, Tan YN, Liu YP, Song X, Zeng L, Gu HH, Tang M, Li W, Yi W, Cao Y. RETRACTED: Nuclear factor kappa B (NFκB) dependent modulation of Epstein–Barr virus latent membrane protein 1 (LMP1) in epidermal growth factor receptor (EGFR) promoter activity. Virus Res 2004; 104:61-70. [PMID: 15177893 DOI: 10.1016/j.virusres.2004.03.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2003] [Revised: 03/03/2004] [Accepted: 03/03/2004] [Indexed: 10/26/2022]
Abstract
The Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) oncoprotein may cause multiple cellular changes, including the induction of epidermal growth factor receptor (EGFR) expression and the activation of the nuclear factor kappa B (NFkappaB) transcription factor. LMP1 increases the levels of both EGFR protein and mRNA but does not stabilize EGFR mRNA. Thus the effects of LMP1 are likely to be mediated by direct activation of the EGFR promoter. In this study, induction of LMP1 increased the EGFR in both protein and promoter levels in a dose dependent manner using tetracycline-regulated LMP1 expression in nasopharyngeal carcinoma (NPC) cell line. Mutational analysis of the LMP1 protein indicated that the C-terminal activation region-1 (CTAR1) domain was mainly involved in the EGFR promoter induction, while CTAR2 was necessary but not sufficient to induce EGFR promoter. Inhibition of LMP1 mediated NFkappaB activation by constitutive repressive inhibitory kappa B alpha (IkappaBalpha) marginally decreased EGFR promoter activity using transiently transfected IkappaBalpha dominant negative mutant. Promoter mutagenesis analysis demonstrated that two putative NFkappaB binding sites of EGFR promoter were very necessary for the transcriptional activity of EGFR induced by LMP1, the proximal NFkappaB binding site was more important than the distal NFkappaB binding site. Taken together, Epstein-Barr virus latent membrane protein 1 modulated the EGFR promoter activity in a NFkappaB dependent manner.
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Li Pira G, Bottone L, Ivaldi F, Pelizzoli R, Bracci L, Lozzi L, Scarso L, Tripodi G, Manca F. Recognition of cmv pp65 protein antigen by human cd4 t-cell lines induced with an immunodominant peptide pool. Hum Immunol 2004; 65:537-43. [PMID: 15172454 DOI: 10.1016/j.humimm.2004.02.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2003] [Revised: 01/15/2004] [Accepted: 02/03/2004] [Indexed: 11/25/2022]
Abstract
Cellular immunity against cytomegalovirus (CMV) is essential for recovery from infection and control of viral latency. In immunocompromised hosts, this balance between CMV and cellular immunity is lost. Accordingly, restoration of the CD8 compartment specific for CMV is beneficial for immunocompromised patients. It is clear that CMV-specific CD4 cells provide helper functions facilitating long-term persistence of CD8 cells. Considering the dearth of data on CMV-specific T-helper cells, we investigated the CD4 responses to the immunodominant protein pp65 to define antigenic peptides. Such peptides were pooled and used to generate long-term T-cell lines. The lines were responsive to CMV and pp65. T cells were selected with individual peptides to produce monospecific lines for accurate definition of fine epitope specificity and to confirm human leukocyte antigen HLA-DR restriction. Furthermore, these lines lost alloreactivity, suggesting that they can be generated from the allodonor for adoptive immunoreconstitution of stem cell graft recipients.
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Kalady MF, Onaitis MW, Emani S, Abdel-Wahab Z, Tyler DS, Pruitt SK. Sequential delivery of maturation stimuli increases human dendritic cell IL-12 production and enhances tumor antigen-specific immunogenicity. J Surg Res 2004; 116:24-31. [PMID: 14732346 DOI: 10.1016/j.jss.2003.09.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Despite the increasing use of dendritic cells (DCs) in clinical trials, questions regarding the optimal means of DC preparation, in particular how to achieve optimal maturation, remain unanswered. We hypothesized that delivering two separate sequential maturation signals to DC in vitro, mimicking the process of DC maturation that occurs in vivo, would enhance the ability of DCs to generate antigen-specific effector T cells in an experimental in vitro antimelanoma model. MATERIALS AND METHODS Human monocyte-derived DCs were transfected with mRNA encoding melanoma-associated antigen Mart-1 (MART) or influenza M1 matrix protein (M1). After mRNA transfection, DCs were left untreated or exposed to different maturation stimuli either added simultaneously or delivered sequentially 18 h after first stimulation. Phenotypic DC cell-surface marker changes and IL-12 secretion were analyzed. Specific antigen presentation by DCs was measured by IFN-gamma release Elispot assay using a CD8(+) MART peptide-specific T cell clone. RNA-transfected and treated DCs were cultured with autologous naive T cells and the induction of antigen-specific effector T cells were assessed by IFN-gamma release Elispot assay. RESULTS DCs transfected and matured had increased cell-surface expression of CD40 and costimulatory molecules CD80, and CD86. DCs matured and further treated by soluble CD40 ligand (sCD40L) had a 10- and 2-fold increase in MART antigen presentation compared to untreated (immature) DCs and DCs treated only with a first maturation signal, respectively (Elispot P = 0.02). Delivery of sequential maturation stimuli resulted in maximal DC IL-12 secretion compared to simultaneous stimuli. Last, generation of antigen-specific effector T cells more than doubled with the sequential addition of sCD40L to mature DC stimulators (Elispot P = 0.009). CONCLUSIONS Maturation of DCs following mRNA transfection increases expression of cell-surface costimulatory molecules. Delivery of a second sequential maturation stimulus enhances antigen presentation, increases IL-12 secretion, and augments immunogenicity as evidenced by generation of tumor antigen-specific effector T cells. This strategy should be considered in the future development of RNA-based DC vaccine strategies for the treatment of cancer.
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Chen F, Liu C, Lindvall C, Xu D, Ernberg I. Epstein-Barr virus latent membrane 2A (LMP2A) down-regulates telomerase reverse transcriptase (hTERT) in epithelial cell lines. Int J Cancer 2004; 113:284-9. [PMID: 15389515 DOI: 10.1002/ijc.20594] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The latent membrane protein (LMP) 2A, one of the membrane-spanning polypeptides encoded by the Epstein-Barr virus (EBV), has been implicated in the maintenance of viral latency and appears to function in part by inhibiting B-cell receptor (BCR) signaling through its ITAM motifs. It has also been suggested that LMP2A is involved in tumorigenesis mediated by EBV. In our study, we determined regulatory effects of LMP2A on the telomerase reverse transcriptase (hTERT) expression. We observed a significant and constant reduction of hTERT mRNA accompanied by decreased telomerase activity in epithelial cells expressing LMP2A. It was further shown that LMP2A inhibited the hTERT promoter activity in transient transfections of both B cells and epithelial cells, and that the ITAM motif was required for this inhibition. Thus LMP2A expression leads to the transcriptional repression of the hTERT gene through specific pathways, which may thereby contribute to the control of EBV-latency.
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Provenzano M, Lim JB, Mocellin S, Monsurro V, Bettinotti M, Marincola FM, Stroncek DF. The matrix protein pp65(341-350): a peptide that induces ex vivo stimulation and in vitro expansion of CMV-specific CD8+ T cells in subjects bearing either HLA-A*2402 or A*0101 allele. Transfusion 2003; 43:1567-74. [PMID: 14617317 DOI: 10.1046/j.1537-2995.2003.00564.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
BACKGROUND The stimulation of PBMNCs with HLA Class I restricted synthetic peptides derived from CMV phosphorylated matrix protein 65 (pp65) evokes CMV-specific cytotoxic T lymphocyte (CTL) activity, a necessary condition for initiating adoptive immunotherapy against CMV-related diseases in immune-compromised patients. It was previously demonstrated that the CMV decamer (10-mer) peptide pp65(341-350), QYDPVAALFF, was able to induce CMV-specific CTLs in HLA-A*2402 CMV-seropositive individuals. STUDY DESIGN AND METHOD We investigated the ability of the peptide pp65(341-350) to reactivate memory CD8+ T cells in CMV-seropositive subjects bearing either the HLA-A24 or A1 allele. CTL responses were measured by IFN-gamma mRNA expression and IFN-gamma protein production as well as cytotoxic activity. RESULTS In this study it was found that peptide pp65(341-350) induced a specific reactivation of memory CD8+ T cells from CMV-seropositive donors expressing either HLA-A*2402 and/or HLA-A*0101. Moreover, a pp65(341-350)-specific selection and expansion using PBMNCs of CMV-seropositive donors bearing both HLA-A*2402 and HLA-A*0101 alleles produced cytotoxic CTLs to both HLA-A24 and A1 peptide-pulsed and autologous CMV-infected target cells. CONCLUSION The results demonstrate that pp65(341-350) induced a specific CTL activity at both molecular and protein levels and that the peptide is specifically processed, presented, and recognized by subjects bearing HLA-A*2402 and/or A*0101. These findings suggest that it may be possible to use this single immune dominant peptide to induce and expand CMV-reactive CTLs for the treatment of individuals with both HLA-A24 and A1 types.
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Toyoda T. [Target of developing the new anti-influenza virus reagents]. NIHON RINSHO. JAPANESE JOURNAL OF CLINICAL MEDICINE 2003; 61:1980-6. [PMID: 14619442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
Two types of specific anti-influenza virus drugs are available in Japan; amantadine and neuraminidase inhibitors(zanamivir and osertamivir). Because of emerging of drug-resistant viruses, we have to develop new types of antiviral reagents. New type anti-influenza virus reagents are developed against viral specific growth steps other than M2 ion channel or NA. Cleavage and activation, attachment, and fusion steps are unique to HA. Transcription initiation step is unique to the viral RNA polymerase. The capped short RNA inhibited the viral RNA polymerase. The peptide derived from matrix protein inhibited the RNA polymerase activity. Antisense oligonucleotide, DNA enzyme and RNAi are also available to inhibit gene expression of influenza virus.
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Gou XM, Chen Y, Chen XY, Arrand JR. [Effects of Epstein-Barr virus latent membrane protein 1(EBV-LMP1) on related factors of metastasis of nasopharyngeal carcinoma cell line CNE1]. AI ZHENG = AIZHENG = CHINESE JOURNAL OF CANCER 2003; 22:481-5. [PMID: 12753707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
BACKGROUND & OBJECTIVE It has been proved that Epstein- Barr virus (EBV) latent membrane protein 1 (EBV-LMP1) can induce the expression of matrix metalloproteinase-9 (MMP-9). This study was designed to investigate the effect of EBV-LMP1 on related factors of metastasis of nasopharyngeal carcinoma cell line CNE1. METHODS Expression of MMP-9 was studied in human NPC cell lines cultured in vitro: CNE1 (well differentiated cell line of NPC) and CNE1-GL (CNE1 cell line transfected with an eukaryotic LMP1-expression plasmid) by SP immunohistochemistry and Western blot analysis. Cell-matrix adhesion assay was used to study the adhesive ability of CNE1-GL cells. The effects of LMP1 on the invasion and migration of CNE1 cells were investigated by transwell methods. RESULTS MMP-9 was expressed in both cell lines but the intensity of the staining was different. The positive rates of expression of MMP-9 in CNE1 and CNE1-GL cells were 30.2% and 98.2%, respectively (P< 0.05). The increased expression of MMP-9 was also shown in CNE1-GL cells by Western blot analysis. Cell-matrix adhesion assay showed that the adhesive ability of CNE1-GL with the matrix (mean A value: 1.2508+/-0.0711) was higher than that of CNE1 cell (mean A value: 0.9519+/-0.068) (P< 0.001). Invasion assay and migration assay showed that the invasion and migration of CNE1-GL cell were higher than those of CNE1 cells (P< 0.01). CONCLUSION The transfection of LMP1 can increase the expression of MMP-9 in CNE1 cells. Abilities of adhesion, migration, and invasion of CNE1 cell were induced by LMP1. It is suggested that MMP-9 may have a role in the LMP1-induced acceleration of invasion and metastasis of NPC cells.
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Prince S, Keating S, Fielding C, Brennan P, Floettmann E, Rowe M. Latent membrane protein 1 inhibits Epstein-Barr virus lytic cycle induction and progress via different mechanisms. J Virol 2003; 77:5000-7. [PMID: 12663807 PMCID: PMC152124 DOI: 10.1128/jvi.77.8.5000-5007.2003] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Epstein-Barr virus (EBV) is a potent growth-transforming agent of human B cells. It has previously been shown that viral latent membrane protein 1 (LMP1) is essential for EBV-induced transformation of normal B cells and contributes to maintenance of latency in vitro. Using the EBV-positive Burkitt's lymphoma line P3HR1-c16, which lacks LMP1 during latency and which can readily be activated into virus-productive lytic cycle, we found that LMP1 inhibits lytic cycle induction via the transcription factor NF-kappa B. In addition, LMP1 inhibits lytic cycle progress via two distinct NF-kappa B-independent mechanisms: one involving the cytosolic C-terminal activating regions and the other involving the transmembrane region of LMP1. These findings indicate that in B cells EBV self-limits its lytic cycle via three distinct LMP1-mediated mechanisms.
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Kopecky SA, Lyles DS. Contrasting effects of matrix protein on apoptosis in HeLa and BHK cells infected with vesicular stomatitis virus are due to inhibition of host gene expression. J Virol 2003; 77:4658-69. [PMID: 12663772 PMCID: PMC152120 DOI: 10.1128/jvi.77.8.4658-4669.2003] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Vesicular stomatitis virus (VSV) is a potent inducer of apoptosis in host cells. Recently, it has been shown that two VSV products are involved in the induction of apoptosis, the matrix (M) protein, and another viral product that has yet to be identified (S. A. Kopecky et. al., J. Virol. 75:12169-12181, 2001). Comparison of recombinant viruses containing wild-type (wt) or mutant M proteins showed that wt M protein accelerates VSV-induced apoptosis in HeLa cells, while wt M protein delays apoptosis in VSV-infected BHK cells. Our hypothesis to explain these results is that both effects of M protein are due to the ability of M protein to inhibit host gene expression. This hypothesis was tested by infecting cells with an M protein mutant virus defective in the inhibition of host gene expression (rM51R-M virus) in the presence or absence of actinomycin D, another inhibitor of host gene expression. Actinomycin D accelerated induction of apoptosis of HeLa cells infected with rM51R-M virus and delayed apoptosis in BHK cells infected with rM51R-M virus, similar to the effects of wt M protein. The idea that the induction of apoptosis by M protein in HeLa cells is due to its ability to inhibit host gene expression was further tested by comparing the activation of upstream caspase pathways by M protein versus that by actinomycin D or 5,6-dichlorobenzimidazole riboside (DRB). Expression of M protein activated both caspase-8 and caspase-9-like enzymes, as did treatment with actinomycin D or DRB. Induction of apoptosis by M protein, actinomycin D, and DRB was inhibited in stably transfected HeLa cell lines that overexpress Bcl-2, an antiapoptotic protein that inhibits the caspase-9 pathway. A synthetic inhibitor of caspase-8, Z-IETD-FMK, did not inhibit induction of apoptosis by M protein, actinomycin D, or DRB. Taken together, our data support the hypothesis that the induction of apoptosis by M protein is caused by the inhibition of host gene expression and that the caspase-9 pathway is more important than the caspase-8 pathway for the induction of apoptosis by M protein and other inhibitors of host gene expression.
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Abstract
CD40 is an important regulator of diverse aspects of the immune response including the T-cell-dependent humoral immune response, the development of antigen-presenting cells (APCs) and inflammation. Latent membrane protein 1 (LMP1), a protein encoded by Epstein-Barr Virus (EBV), appears to mimic CD40 in multiple ways. CD40 and LMP1 bind similar sets of cellular signalling proteins and activate overlapping signalling pathways. Despite many similarities shared between CD40 and LMP1, they also differ substantively. In this review, we will compare and contrast the signalling mediated by CD40 and LMP1.
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Bishop GA, Hostager BS, Brown KD. Mechanisms of TNF receptor-associated factor (TRAF) regulation in B lymphocytes. J Leukoc Biol 2002; 72:19-23. [PMID: 12101258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023] Open
Abstract
A key component of signaling by members of the tumor necrosis factor receptor (TNF-R) family is interaction with the cytoplasmic adapter proteins known as TRAFs. Several proteins encoded by microbes also interact with TRAFs. A notable example is the CD40 receptor, expressed on antigen presenting cells and providing key activation signals in T cell-dependent B cell activation. CD40 signals to B cells are mimicked by a constitutively active viral protein produced by the Epstein-Barr virus. For each of these receptors, multiple mechanisms of TRAF regulation contribute to signal transduction and the ultimate effect on the B cell. Recent findings concerning these regulatory mechanisms are summarized in this overview.
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Prokova V, Mosialos G, Kardassis D. Inhibition of transforming growth factor beta signaling and Smad-dependent activation of transcription by the Latent Membrane Protein 1 of Epstein-Barr virus. J Biol Chem 2002; 277:9342-50. [PMID: 11781310 DOI: 10.1074/jbc.m109099200] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Inhibition of transforming growth factor beta (TGFbeta) signaling by the Epstein-Barr virus Latent Membrane Protein 1 (LMP1) may account, at least in part, for the oncogenic activity of LMP1. We found that LMP1 is a potent inhibitor of TGFbeta signaling and Smad-dependent activation of transcription in 293 epithelial cells and COS-7 fibroblasts. LMP1 strongly inhibited the uninduced and the Smad-inducible activity of the promoters of the human p21/WAF1/Cip1 gene and the mouse Smad7 gene. Inhibition of TGFbeta signaling and Smad-dependent activation of transcription by LMP1 was greatly reduced by deletion of both C-terminal activating regions 1 and 2 of LMP1 as well as by overexpression of a non-degradable form of IkappaB. In contrast, specific inhibitors of p38 kinase or MEK kinase did not reverse the inhibitory activity of LMP1. TGFbeta signaling was enhanced by overexpression of dominant negative forms of the LMP1 effectors TRAF2, NIK, and IKKbeta and was abolished by overexpression of p65/RelA or a p50/p65 fusion protein. Deletion of the transactivation domain of p65 abolished its inhibitory activity. Immunoblotting and immunofluorescence microscopy indicated that suppression of TGFbeta signaling and Smad transcriptional activity by LMP1 was not due to Smad degradation or cytoplasmic retention suggesting that LMP1 affects the nuclear function of Smad proteins. Our data are consistent with an essential role of NF-kappaB activation by LMP1 in the inhibition of TGFbeta signaling and Smad-mediated transcriptional responses.
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Wang C, Deng X, Li X, Gu H, Yi W, Weng X, Xia L, Cao Y. [Matrix metalloproteinase 9 expression is induced by Epstein-Barr virus LMP1 via NF-kappa B or AP-1 signaling pathway in nasopharyngeal carcinoma cells]. ZHONGHUA ZHONG LIU ZA ZHI [CHINESE JOURNAL OF ONCOLOGY] 2002; 24:9-13. [PMID: 11977651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
OBJECTIVE To clarify if Epstein-Barr virus encoded LMP1 induces matrix metalloproteinase 9 expression via NF-kappa B or AP-1 signaling pathway, which gives evidence to the elucidation of the mechanism of LMP1- mediated carcinogenesis. METHODS To determine whether LMP1 or its mutants contribute to MMP9 production via NF-kappa B or AP-1 transcription factor, MMP9-chloramphenicol acetyl transferase (CAT), NF-kappa B mut 9-CAT, AP-1 mut MMP9-CAT were transfected into human nasopharyngeal carcinoma cells stably expressing LMP1 (HNE2-LMP1) or its mutants, [HNE2-LMP1 (1-185), HNE2-LMP1 (1-231), HNE2-LMP1 delta 187-351] by electroporation technic. The difference of MMP9 reporter activity among those cell lines was detected by CAT assay and expression of MMP9 was determined in nasopharyngeal carcinoma cells stably expressing LMP1 or its mutants by zymographic analysis. In the meantime, efforts were made to demonstrate if LMP1 regulates NF-kappa B or AP-1 activation using reporter gene analysis. RESULTS In contrast with vector-transfected cells, MMP9 CAT activity in HNE2-LMP1, HNE2-LMP1 (1-185), HNE2-LMP1(1-231), HNE2-LMP1 delta 187-351 increased 7.2, 1.3, 3.3, 4.0 times respectively. Zymographic analysis demonstrated that the 92 kDa MMP9 expression was induced in HNE2-LMP1, HNE2-LMP1(1-231) and HNE2-LMP1 delta 187-351 cells, whereas it was negative in HNE2-pSG5 and HNE2-LMP1 (1-185) cells. As compared to the HNE2 cells, NF-kappa B or AP-1 reporter activity in HNE2-LMP1 cells were increased 13.8, 8.4 fold respectively. Moreover, In contrast with MMP9 CAT-transfected cells, MMP9 CAT activity in NF-kappa B mut MMP9-CAT or AP-1 mut MMP9-CAT transfected HNE2-LMP1, HNE2-LMP1 (1-185), HNE2-LMP1(1-231) and HNE2-LMP1 delta 187-351 cells were significantly decreased by 18.1% or 16.3%, 35.0% or 33.3%, 29.1% or 26.1% from the original level. However, there was no difference in NF-kappa B mut MMP9-CAT or AP-1 mut MMP9-CAT transfected HNE2-pSG5, HNE2-LMP1 (1-185) cells. CONCLUSION In nasophargyngeal carcinoma, Epstein-Barr virus-encoded LMP1 induces MMP9 transcription and enzymatic activity via an NF-kappa B or AP-1 signaling pathway, which may contribute to invasiveness and metastasis.
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Busch LK, Bishop GA. Multiple carboxyl-terminal regions of the EBV oncoprotein, latent membrane protein 1, cooperatively regulate signaling to B lymphocytes via TNF receptor-associated factor (TRAF)-dependent and TRAF-independent mechanisms. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:5805-13. [PMID: 11698454 DOI: 10.4049/jimmunol.167.10.5805] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Latent membrane protein 1 (LMP1) is an EBV-encoded transforming protein that strongly mimics the B cell-activating properties of a normal cellular membrane protein, CD40. LMP1 and CD40 both associate with the cytoplasmic adapter proteins called TNFR-associated factors (TRAFs). TRAFs 1, 2, and 3 bind to a region of LMP1 that is essential for EBV to transform B lymphocytes, carboxyl-terminal activating region (CTAR) 1. However, studies of transiently overexpressed LMP1 molecules, primarily in epithelial cells, indicated that a second region, CTAR2, is largely responsible for LMP1-mediated activation of NF-kappaB and c-Jun N-terminal kinase. To better understand LMP1 signaling in B lymphocytes, we performed a structure-function analysis of the LMP1 C-terminal cytoplasmic domain stably expressed in B cell lines. Our results demonstrate that LMP1-stimulated Ig production, surface molecule up-regulation, and NF-kappaB and c-Jun N-terminal kinase activation require both CTAR1 and CTAR2, and that these two regions may interact to mediate LMP1 signaling. Furthermore, we find that the function of CTAR1, but not CTAR2, correlates with TRAF binding and present evidence that as yet unidentified cytoplasmic proteins may associate with LMP1 to mediate some of its signaling activities.
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Lee IS, Shin YK, Chung DH, Park SH. LMP1-induced downregulation of CD99 molecules in Hodgkin and Reed-Sternberg cells. Leuk Lymphoma 2001; 42:587-94. [PMID: 11697486 DOI: 10.3109/10428190109099318] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Hodgkin's and Reed-Sternberg (H-RS) cells are morphological hallmarks of Hodgkin's disease (HD). So far, several characteristics frequently seen in H-RS cells from different origins have been described, such as the high expression of Epstein-Barr virus latent membrane protein 1 (LMP1), the elevation of NF-kappaB activity, and the aberrant expression of molecules such as CD15, CD30, and CD99. Despite extensive studies on the nature of H-RS cells, the molecular mechanism by which H-RS cells are generated remained elusive. Recently, the forced down-regulation of CD99 was reported to induce typical H-RS phenotypes in vitro in a B cell line. Furthermore, it was revealed that LMP1 markedly reduces the CD99 expression at the transcriptional level. Since the presence of LMP1 is known to be associated with the H-RS cell formation, the data provide a possibility of linkage between LMP1 and HD via CD99, thus suggesting that, at least in part, the loss of CD99 may play a critical role in the pathogenic sequence to the formation of H-RS cells in HD. In this review, the role of CD99 in the generation of H-RS cells and its molecular mechanism will be suggested.
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Horikawa T, Sheen TS, Takeshita H, Sato H, Furukawa M, Yoshizaki T. Induction of c-Met proto-oncogene by Epstein-Barr virus latent membrane protein-1 and the correlation with cervical lymph node metastasis of nasopharyngeal carcinoma. THE AMERICAN JOURNAL OF PATHOLOGY 2001; 159:27-33. [PMID: 11438450 PMCID: PMC1850422 DOI: 10.1016/s0002-9440(10)61669-0] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Nasopharyngeal carcinoma (NPC) is distinctive in head and neck carcinomas for its close association with Epstein-Barr virus and its highly metastatic nature. Up-regulation of cell motility is essential for enhancement of metastatic potential. The expression of c-Met proto-oncogene, a high-affinity receptor for hepatocyte growth factor/scatter factor, has been reported to correlate with metastatic ability of the tumor cell. We observed close association of c-Met expression with cervical lymph node metastasis (P = 0.0272) in 39 NPC specimens studied immunohistochemically. Epstein-Barr virus-encoding latent membrane protein-1 (LMP-1) is a primary oncogene and is suggested to enhance the metastatic property of NPC. Previously, we reported that LMP-1 enhanced the motility of Madin-Darby canine kidney (MDCK) epithelial cells that was mediated by activation of Ets-1 transcription factor. Therefore, we examined the interrelationships of LMP-1, Ets-1, and c-Met. In immunohistochemical studies, the expression of LMP-1, Ets-1, and c-Met correlated significantly with each other in NPC (LMP-1 versus Ets-1, P < 0.0001; Ets-1 versus c-Met, P = 0.0012; LMP-1 versus Met, P = 0.0005). Transfection of LMP-1-expressing plasmid in MDCK cells induced c-Met protein expression. The c-Met protein was also induced by Ets-1 expression, and induction of c-Met by LMP-1 was suppressed by introducing a dominant-negative form of Ets-1 in LMP-1-expressing MDCK cells. These results suggest that LMP-1 induces c-Met through the activation of Ets-1, which may contribute in part to the highly metastatic potential of NPC.
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Lee I, Kim MK, Choi EY, Mehl A, Jung KC, Gil MC, Rowe M, Park SH. CD99 expression is positively regulated by Sp1 and is negatively regulated by Epstein-Barr virus latent membrane protein 1 through nuclear factor-kappaB. Blood 2001; 97:3596-604. [PMID: 11369656 DOI: 10.1182/blood.v97.11.3596] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Epstein-Barr virus (EBV)-encoded latent membrane protein-1 (LMP1) is highly expressed in Hodgkin and Reed-Sternberg (H-RS) cells from patients with EBV-associated Hodgkin disease. It was previously demonstrated that CD99 can be negatively regulated by LMP1 at the transcriptional level, and the decreased expression of CD99 in a B lymphocyte cell line generates H-RS-like cells. In this study, detailed dissection of the CD99 promoter region was performed to search regulatory factor(s) involved in the expression of the gene. Using various mutant constructs containing deletions in the promoter region, it was revealed that the maximal promoter activity was retained on 5'-deletion to the position -137 from the transcriptional initiation site. Despite the presence of multiple putative Sp1-binding sites in the promoter region, the site located at -95 contributes heavily as a positive cis-acting element to its basal promoter activity. However, on examination of the involvement of the positive-acting Sp1-binding site of the promoter for the repressive activity of LMP1, it appeared to be dispensable. Instead, the repressive effect was mapped to the nuclear factor (NF)-kappaB activation domains in the cytoplasmic carboxyl terminus of LMP1 despite the absence of the NF-kappaB consensus sequences in the CD99 promoter region. Furthermore, the decreased CD99 promoter activity by LMP1 was markedly restored when NF-kappaB activity was inhibited. Taken together, these data suggest that Sp1 activates, whereas LMP1 represses, transcription from the CD99 promoter through the NF-kappaB signaling pathway, and they might aid in the understanding of the molecular mechanisms of viral pathogenesis in EBV-positive Hodgkin disease. (Blood. 2001;97:3596-3604)
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Maecker HT, Ghanekar SA, Suni MA, He XS, Picker LJ, Maino VC. Factors affecting the efficiency of CD8+ T cell cross-priming with exogenous antigens. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:7268-75. [PMID: 11390476 DOI: 10.4049/jimmunol.166.12.7268] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Processing of exogenous protein Ags by APC leads predominantly to presentation of peptides on class II MHC and, thus, stimulation of CD4+ T cell responses. However, "cross-priming" can also occur, whereby peptides derived from exogenous Ags become displayed on class I MHC molecules and stimulate CD8+ T cell responses. We compared the efficiency of cross-priming with exogenous proteins to use of peptide Ags in human whole blood using a flow cytometry assay to detect T cell intracellular cytokine production. CD8+ T cell responses to whole CMV proteins were poorly detected (compared with peptide responses) in most CMV-seropositive donors. Such responses could be increased by using higher doses of Ag than were required to achieve maximal CD4+ T cell responses. A minority of donors displayed significantly more efficient CD8+ T cell responses to whole protein, even at low Ag doses. These responses were MHC class I-restricted and dependent upon proteosomal processing, indicating that they were indeed due to cross-priming. The ability to efficiently cross-prime was not a function of the number of dendritic cells in the donor's blood. Neither supplementation of freshly isolated dendritic cells nor use of cultured, Ag-pulsed dendritic cells could significantly boost CD8 responses to whole-protein Ags in poorly cross-priming donors. Interestingly, freshly isolated monocytes performed almost as well as dendritic cells in inducing CD8 responses via cross-priming. In conclusion, the efficiency of cross-priming appears to be poor in most donors and is dependent upon properties of the individual's APC and/or T cell repertoire. It remains unknown whether cross-priming ability translates into any clinical advantage in ability to induce CD8+ T cell responses to foreign Ags.
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45
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Liao W, Tang M, Yin L. [EBV latent membrane protein 1 induces p53 expression via NF-kappa B in nasopharyngeal carcinoma]. ZHONGHUA ZHONG LIU ZA ZHI [CHINESE JOURNAL OF ONCOLOGY] 2001; 23:199-201. [PMID: 11783085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To ascertain if EBV-encoded latent membrane protein 1 (LMP1) induces p53 expression via NF-kappa B signaling. METHODS A nasopharyngeal carcinoma cell line, Tet-on-LMP1 HNE2, transfected with LMP1, the expression of which was regulated by tetracycline, was used in this study. Functional activity of NF-kappa B was determined by luciferase reporter assay and expression of p53 and bcl-2 was detected by Western blot. RESULTS LMP1 induced p53 expression via NF-kappa B signaling pathway. Induction of p53 expression could be blocked by phosphorothiate analogs of antisense oligonucleotides to NF-kappa B p65 and LMP1, but not by NF-kappa B p50. However, it seemed that LMP1 had no influence on bcl-2 expression in nasopharyngeal carcinoma. CONCLUSION Induction expression of p53 by EBV-encoded LMP1 implies that p53 may act as a mediator in apoptosis triggered by LMP1, which brings about a complex balance in nasopharyngeal carcinogenesis.
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Komanduri KV, Donahoe SM, Moretto WJ, Schmidt DK, Gillespie G, Ogg GS, Roederer M, Nixon DF, McCune JM. Direct measurement of CD4+ and CD8+ T-cell responses to CMV in HIV-1-infected subjects. Virology 2001; 279:459-70. [PMID: 11162802 DOI: 10.1006/viro.2000.0697] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Data from murine models of chronic viral infection suggest that CD4+ T-cell responses to viral pathogens are important in sustaining the number and/or function of CD8+ cytotoxic T-cell (CTL) effectors. In this study, we used cytokine flow cytometry (CFC), staining with HLA-A*0201-peptide tetramers, and peptide stimulation with epitopic peptides to study functional CD4+ and CD8+ T-cell responses to cytomegalovirus (CMV) in human subjects coinfected with CMV and the human immunodeficiency virus, type 1 (HIV-1). We show that strong CD4+ and CD8+ T-cell responses to CMV antigens are sustained over time in HIV-1-infected individuals. Those who maintain a strong CD4+ T-cell response to CMV are also likely to maintain higher frequencies of CD8+ T cells capable of binding to HLA-A*0201-CMV pp65 (A2-pp65) tetramers as well as responses to pp65 peptide stimulation with effector cytokine production. These data support the hypothesis that declines in frequencies of CD4+ T-cell responses to CMV are associated with an inability to sustain high levels of CMV-specific CD8+ T-cell responses in HIV-1-infected subjects. These declines may precede the onset of CMV-associated end organ disease.
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Dyall J, Latouche JB, Schnell S, Sadelain M. Lentivirus-transduced human monocyte-derived dendritic cells efficiently stimulate antigen-specific cytotoxic T lymphocytes. Blood 2001; 97:114-21. [PMID: 11133750 DOI: 10.1182/blood.v97.1.114] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Dendritic cells (DCs) are professional antigen-presenting cells that are highly effective adjuvants for immunizing against pathogens and tumor antigens. The potential merit of genetic approaches to loading DCs with antigens is to express high and sustained levels of proteins that can be subsequently processed and presented to T lymphocytes. Replication-defective oncoretroviruses are able to efficiently transduce CD34(+) progenitor-derived DCs but not monocyte-derived DCs. Here, it is shown that efficient gene transfer is obtained using a human immunodeficiency virus-1-derived lentiviral vector deleted of all structural and accessory genes. Infection of immature DCs with the lentiviral vector at a multiplicity of infection of 20 resulted in stable gene expression in 30% to 40% of the matured DCs. Proviral DNA was detectable by Alu polymerase chain reaction for the lentiviral but not the oncoretroviral vector. Most importantly, it is demonstrated that lentivirus-transduced DCs were fully functional and effectively activated autologous HLA A2.1(+) peripheral blood cytotoxic T lymphocytes (CTLs). DCs expressing lentiviral vector-encoded Flu peptide were at least as efficient as DCs pulsed with the same peptide in stimulating specific CTLs. The efficacy of the lentivirus-transduced DCs was further demonstrated by their ability to directly activate freshly harvested peripheral blood Flu-specific CTLs in the absence of CD4(+) T-cell help and exogenous cytokines. The availability of a stable gene delivery system based on a multiply attenuated lentivirus that does not encode any viral protein and that allows sustained antigen presentation by DCs derived from blood monocytes will be very useful for the biologic investigation of DCs and the improvement of immunotherapeutic strategies involving DCs.
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Vivarelli M, De Ruvo N, Lazzarotto T, Bellusci R, Landini MP, Varani S, Cavallari A. Abstension from treatment of low-level pp65 cytomegalovirus antigenemia after liver transplantation: a prospective study. Transplantation 2000; 70:1183-7. [PMID: 11063338 DOI: 10.1097/00007890-200010270-00010] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Ganciclovir is a highly effective and relatively safe drug to treat cytomegalovirus (CMV) infection in liver transplant patients; CMV resistance to ganciclovir is progressively emerging due to the extensive use of the drug in transplant and AIDS patients; CMV pp65 antigenemia allows early diagnosis of CMV infection and quantitation of the viral load; preemptive antigenemia-guided therapy of CMV infection can prevent CMV disease but the threshold of antigenemia value above which treatment has to be instituted is unclear. METHODS To demonstrate the safety of abstention from preemptive treatment in the presence of low levels of antigenemia 77 consecutive liver transplant recipients were prospectively evaluated. Antigenemia was tested twice a week from transplantation until discharge, then once a week until the third postoperative month. In absence of risk factors for CMV disease, namely donor positive/recipient negative CMV serology, treatment with antibodies to lymphocytes and retransplantation, only patients with antigenemia of more than 50 or symptoms possibly related to CMV infection had preemptive treatment. RESULTS A total of 32 patients had at least one positive antigenemia test with a value less than 50; 22 (68.7%) spontaneously cleared the virus, 3 were treated with i.v. ganciclovir for the presence of fever, and the other 7 (21,8%) progressed to values of antigenemia of more than 50 and were treated even if asymptomatic. No CMV disease was observed in these patients. CONCLUSION CMV antigenemia less than 50 in liver transplant recipients with low and intermediate risk for CMV disease does not mandate preemptive ganciclovir treatment. Close surveillance with repeated determination of antigenemia until its negativization and careful clinical and laboratory monitoring is advisable.
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Gibson GA, Hill WG, Weisz OA. Evidence against the acidification hypothesis in cystic fibrosis. Am J Physiol Cell Physiol 2000; 279:C1088-99. [PMID: 11003589 DOI: 10.1152/ajpcell.2000.279.4.c1088] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The pleiotropic effects of cystic fibrosis (CF) result from the mislocalization or inactivity of an apical membrane chloride channel, the cystic fibrosis transmembrane conductance regulator (CFTR). CFTR may also modulate intracellular chloride conductances and thus affect organelle pH. To test the role of CFTR in organelle pH regulation, we developed a model system to selectively perturb the pH of a subset of acidified compartments in polarized cells and determined the effects on various protein trafficking steps. We then tested whether these effects were observed in cells lacking wild-type CFTR and whether reintroduction of CFTR affected trafficking in these cells. Our model system involves adenovirus-mediated expression of the influenza virus M2 protein, an acid-activated ion channel. M2 expression selectively slows traffic through the trans-Golgi network (TGN) and apical endocytic compartments in polarized Madin-Darby canine kidney (MDCK) cells. Expression of M2 or treatment with other pH perturbants also slowed protein traffic in the CF cell line CFPAC, suggesting that the TGN in this cell line is normally acidified. Expression of functional CFTR had no effect on traffic and failed to rescue the effect of M2. Our results argue against a role for CFTR in the regulation of organelle pH and protein trafficking in epithelial cells.
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D'Addario M, Ahmad A, Morgan A, Menezes J. Binding of the Epstein-Barr virus major envelope glycoprotein gp350 results in the upregulation of the TNF-alpha gene expression in monocytic cells via NF-kappaB involving PKC, PI3-K and tyrosine kinases. J Mol Biol 2000; 298:765-78. [PMID: 10801347 DOI: 10.1006/jmbi.2000.3717] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Epstein-Barr virus (EBV) is a human herpesvirus that interacts with various immunocompetent cells that carry the EBV receptor (CD21/CR2). EBV binds to CR2 through its major envelope glycoprotein 350 (gp350). Previously we had demonstrated that EBV and other human herpesviruses are capable of modulating cytokine synthesis through the deregulated expression of cytokine genes interleukin-1 (IL-1), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and interleukin-2 (IL-2). Here we show that, in contrast to infectious EBV, purified recombinant gp350 upregulates TNF-alpha gene expression in human monocyte/macrophages (M/M) as well as in a monocytoid cell line, U937. Our results also demonstrate that this increased expression is due to both enhanced transcription and stability of TNF-alpha mRNA in gp350-treated cells. The specificity of this effect is evidenced by the fact that pre-incubation of cells with anti-CR2 monoclonal antibody OKB7, which blocks binding of gp350 to CR2, inhibits the above mentioned effects of gp350. Furthermore, we demonstrate that activation of TNF-alpha by gp350 is mediated by NF-kappaB through signal transduction pathways involving PKC, PI3-K and tyrosine kinases. To our knowledge this is the first report describing the modulation of TNF-alpha gene expression by the EBV-gp350 molecule following its interaction with the viral receptor CR2 on cells of the monocytic lineage.
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MESH Headings
- Antibodies, Monoclonal/immunology
- Antibodies, Monoclonal/pharmacology
- Cells, Cultured
- Cyclic AMP Response Element-Binding Protein/metabolism
- Dactinomycin/pharmacology
- Half-Life
- Herpesvirus 4, Human/physiology
- Humans
- Monocytes/drug effects
- Monocytes/enzymology
- Monocytes/metabolism
- NF-kappa B/metabolism
- Phosphatidylinositol 3-Kinases/metabolism
- Phosphoinositide-3 Kinase Inhibitors
- Protein Biosynthesis/drug effects
- Protein Kinase C/antagonists & inhibitors
- Protein Kinase C/metabolism
- Protein-Tyrosine Kinases/antagonists & inhibitors
- Protein-Tyrosine Kinases/metabolism
- RNA Stability/drug effects
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Complement 3d/antagonists & inhibitors
- Receptors, Complement 3d/immunology
- Receptors, Complement 3d/metabolism
- Recombinant Proteins/antagonists & inhibitors
- Recombinant Proteins/genetics
- Recombinant Proteins/metabolism
- Recombinant Proteins/pharmacology
- Signal Transduction/drug effects
- Transcription, Genetic/drug effects
- Tumor Necrosis Factor-alpha/analysis
- Tumor Necrosis Factor-alpha/biosynthesis
- Tumor Necrosis Factor-alpha/genetics
- Tumor Necrosis Factor-alpha/metabolism
- U937 Cells
- Up-Regulation/drug effects
- Viral Matrix Proteins/antagonists & inhibitors
- Viral Matrix Proteins/genetics
- Viral Matrix Proteins/metabolism
- Viral Matrix Proteins/pharmacology
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