共查询到20条相似文献,搜索用时 24 毫秒
1.
Expression of the pX gene of HTLV-I: general splicing mechanism in the HTLV family 总被引:43,自引:0,他引:43
Human T-cell leukemia virus type I (HTLV-I) is an etiological agent of adult T-cell leukemia. A viral gene pX encodes for p40X and it has been proposed that this protein trans-activates the viral long terminal repeat and possibly some cellular genes; this activation may be associated with T-cell transformation. The mechanism of pX gene expression and the primary structure of p40X are now reported. Two-step splicing generates the 2.1-kilobase pX mRNA; the initiator methionine for env becomes part of the pX protein. These splicing signals are conserved among all members of the HTLV family except for the acquired immune deficiency syndrome-associated viruses. 相似文献
2.
U3 sequences from HTLV-I and -II LTRs confer pX protein response to a murine leukemia virus LTR 总被引:8,自引:0,他引:8
H Kitado I S Chen N P Shah A J Cann K Shimotohno H Fan 《Science (New York, N.Y.)》1987,235(4791):901-904
3.
《Science (New York, N.Y.)》1983,221(4609):418
In table 1 of the report by M. Essex et al., "Antibodies to cell membrane antigens associated with human T-cell leukemia virus in patients with AIDS" (20 May, p. 859), the heading for columns 4 and 5 should have read "Cells positive (> 40 percent)" 相似文献
4.
Inhibition of lymphocyte proliferation by a synthetic peptide homologous to retroviral envelope proteins 总被引:47,自引:0,他引:47
The retroviral transmembrane envelope protein p15E is immunosuppressive in that it inhibits immune responses of lymphocytes, monocytes, and macrophages. A region of p15E has been conserved among murine and feline retroviruses; a homologous region is also found in the transmembrane envelope proteins of the human retroviruses HTLV-I and HTLV-II and in a putative envelope protein encoded by an endogenous C-type human retroviral DNA. A peptide (CKS-17) was synthesized to correspond to this region of homology and was examined for its effects on lymphocyte proliferation. CKS-17 inhibited the proliferation of an interleukin-2-dependent murine cytotoxic T-cell line as well as alloantigen-stimulated proliferation of murine and human lymphocytes. Four other peptides, representing different regions of virus proteins, were inactive. These results suggest that the immunosuppressive portion of retroviral transmembrane envelope proteins may reside, at least in part, in a-conserved sequence represented by the CKS-17 peptide. 相似文献
5.
The pX protein of HTLV-I is a transcriptional activator of its long terminal repeats 总被引:120,自引:0,他引:120
B K Felber H Paskalis C Kleinman-Ewing F Wong-Staal G N Pavlakis 《Science (New York, N.Y.)》1985,229(4714):675-679
6.
Characterization of envelope and core structural gene products of HTLV-III with sera from AIDS patients 总被引:63,自引:0,他引:63
W G Robey B Safai S Oroszlan L O Arthur M A Gonda R C Gallo P J Fischinger 《Science (New York, N.Y.)》1985,228(4699):593-595
The envelope (env) and structural (gag) gene products of human T-cell leukemia (lymphotropic) virus type III were identified by immunoaffinity chromatography, immunoprecipitation, and two-dimensional oligopeptide mapping methods. The env gene specifies a glycosylated polypeptide with a molecular weight of 160,000 (gp160) that is processed to gp120 and smaller gene products. The gag gene specifies two polypeptides of 70,000 and 55,000 molecular weight (p70 and p55), both of which contain p24, the major structural protein of the mature virion. The techniques in this study can be used to define the extent of variability of the env gene product among different virus isolates and may identify the nature and patterns of the humoral immune response that lead to an immunologically protected state. 相似文献
7.
Diagnostic potential for human malignancies of bacterially produced HTLV-I envelope protein 总被引:8,自引:0,他引:8
K P Samuel J A Lautenberger C L Jorcyk S Josephs F Wong-Staal T S Papas 《Science (New York, N.Y.)》1984,226(4678):1094-1097
Two regions of the gene for the human T-cell leukemia virus subgroup I (HTLV-I) envelope were expressed in Escherichia coli by use of the vector pJLA16. One corresponds to the carboxyl terminal region of the major envelope protein p46, and the other corresponds to the transmembrane protein p21E. Reactivity of the expressed protein with human serum was tested by the Western blot procedure. Each of 11 sera tested that had been shown to contain antibodies to HTLV-I or HTLV-II by an enzyme-linked immunosorbent assay recognized the bacterially synthesized envelope proteins. There was no reaction detected when 17 control sera were tested. This system will be useful for large-scale seroepidemiological surveys for HTLV-I and related human retroviruses. 相似文献
8.
9.
Antigens encoded by the 3'-terminal region of human T-cell leukemia virus: evidence for a functional gene 总被引:47,自引:0,他引:47
T H Lee J E Coligan J G Sodroski W A Haseltine S Z Salahuddin F Wong-Staal R C Gallo M Essex 《Science (New York, N.Y.)》1984,226(4670):57-61
Antibodies in sera from patients with adult T-cell leukemia-lymphoma or from healthy carriers of type I human T-cell leukemia virus (HTLV) recognize an antigen of approximately 42 kilodaltons (p42) in cell lines infected with HTLV-I. Radiolabel sequence analysis of cyanogen bromide fragments of p42 led to the conclusion that this antigen is encoded in part by LOR, a conserved portion of the "X" region that is flanked by the envelope gene and the 3' long terminal repeat of HTLV-I. It is possible that this novel product mediates the unique transformation properties of the HTLV family. 相似文献
10.
Antibodies reactive with human T-lymphotropic retroviruses (HTLV-III) in the serum of patients with AIDS 总被引:125,自引:0,他引:125
M G Sarngadharan M Popovic L Bruch J Schüpbach R C Gallo 《Science (New York, N.Y.)》1984,224(4648):506-508
In cats, infection with T-lymphotropic retroviruses can cause T-cell proliferation and leukemia or T-cell depletion and immunosuppression. In humans, some highly T4 tropic retroviruses called HTLV-I can cause T-cell proliferation and leukemia. The subgroup HTLV-II also induces T-cell proliferation in vitro, but its role in disease is unclear. Viruses of a third subgroup of human T-lymphotropic retroviruses, collectively designated HTLV-III, have been isolated from cultured cells of 48 patients with acquired immunodeficiency syndrome (AIDS). The biological properties of HTLV-III and immunological analyses of its proteins show that this virus is a member of the HTLV family, and that it is more closely related to HTLV-II than to HTLV-I. Serum samples from 88 percent of patients with AIDS and from 79 percent of homosexual men with signs and symptoms that frequently precede AIDS, but from less than 1 percent of heterosexual subjects, have antibodies reactive against antigens of HTLV-III. The major immune reactivity appears to be directed against p41, the presumed envelope antigen of the virus. 相似文献
11.
Association of human papillomavirus types 16 and 18 E6 proteins with p53 总被引:175,自引:0,他引:175
Human papillomavirus type 16 (HPV-16) is a DNA tumor virus that is associated with human anogenital cancers and encodes two transforming proteins, E6 and E7. The E7 protein has been shown to bind to the retinoblastoma tumor suppressor gene product, pRB. This study shows that the E6 protein of HPV-16 is capable of binding to the cellular p53 protein. The ability of the E6 proteins from different human papillomaviruses to form complexes with p53 was assayed and found to correlate with the in vivo clinical behavior and the in vitro transforming activity of these different papillomaviruses. The wild-type p53 protein has tumor suppressor properties and has also been found in association with large T antigen and the E1B 55-kilodalton protein in cells transformed by SV40 and by adenovirus type 5, respectively, providing further evidence that the human papillomaviruses, the adenoviruses, and SV40 may effect similar cellular pathways in transformation. 相似文献
12.
Virus envelope protein of HTLV-III represents major target antigen for antibodies in AIDS patients 总被引:41,自引:0,他引:41
F Barin M F McLane J S Allan T H Lee J E Groopman M Essex 《Science (New York, N.Y.)》1985,228(4703):1094-1096
In this study, two glycoproteins (gp160 and gp120) that are encoded by human T-cell lymphoma virus type III (HTLV-III) were the antigens most consistently recognized by antibodies found in patients with the acquired immune deficiency syndrome (AIDS) and with the AIDS-related complex (ARC) and in healthy homosexual males. The techniques used to detect the glycoproteins were radioimmunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (RIP/SDS-PAGE). Although most antibody-positive samples from ARC patients and from healthy homosexual males also reacted with the virus core protein p24, less than half of the AIDS patients revealed a positive band with p24 under the same conditions. The ability to detect antibodies against a profile of both the major env gene encoded antigens and the gag gene encoded antigens suggests that the RIP/SDS-PAGE may be a valuable confirmatory assay for establishing the presence or absence of antibodies to HTLV-III in human serum samples. 相似文献
13.
The human papilloma virus-16 E7 oncoprotein is able to bind to the retinoblastoma gene product 总被引:265,自引:0,他引:265
Deletions or mutations of the retinoblastoma gene, RB1, are common features of many tumors and tumor cell lines. Recently, the RB1 gene product, p105-RB, has been shown to form stable protein/protein complexes with the oncoproteins of two DNA tumor viruses, the adenovirus E1A proteins and the simian virus 40 (SV40) large T antigen. Neither of these viruses is thought to be associated with human cancer, but they can cause tumors in rodents. Binding between the RB anti-oncoprotein and the adenovirus or SV40 oncoprotein can be recapitulated in vitro with coimmunoprecipitation mixing assays. These assays have been used to demonstrate that the E7 oncoprotein of the human papilloma virus type-16 can form similar complexes with p105-RB. Human papilloma virus-16 is found associated with approximately 50 percent of cervical carcinomas. These results suggest that these three DNA viruses may utilize similar mechanisms in transformation and implicate RB binding as a possible step in human papilloma virus-associated carcinogenesis. 相似文献
14.
Infection of HTLV-III/LAV in HTLV-I-carrying cells MT-2 and MT-4 and application in a plaque assay 总被引:120,自引:0,他引:120
The human T-cell lines MT-2 and MT-4 carry the human T-cell leukemia virus type I (HTLV-I). When MT-2 and MT-4 were infected with HTLV-III, the probable etiologic agent of the acquired immune deficiency syndrome (AIDS), rapid cytopathogenic effects and cytotoxicity were observed that made it possible to titrate the biologically active virus in a plaque-forming assay. The cytopathogenic effects were preceded by the rapid induction and increase of HTLV-III antigens as revealed by immunofluorescence and immunoprecipitation. Activities of HTLV-III were neutralized by the human antibodies against the virus when immunofluorescence and plaque assays were used. Essentially the same results were obtained with the lymphadenopathy-associated virus (LAV1). 相似文献
15.
HTLV-III/LAV-neutralizing antibodies to an E. coli-produced fragment of the virus envelope 总被引:87,自引:0,他引:87
S D Putney T J Matthews W G Robey D L Lynn M Robert-Guroff W T Mueller A J Langlois J Ghrayeb S R Petteway K J Weinhold 《Science (New York, N.Y.)》1986,234(4782):1392-1395
Immunization with either an Escherichia coli recombinant segment of the human T-cell lymphotropic virus (HTLV-III/LAV) envelope protein (gp 120) or with deglycosylated gp 120 envelope protein produced antibodies that neutralize HTLV-III/LAV infection in vitro. Virus neutralization titers of these antisera were equivalent to those obtained with purified native gp120 as immunogen. This localizes at least one class of neutralizing epitopes to the carboxyl-terminal half of the molecule. In addition, native gp120 prevented HTLV-III/LAV--mediated cell fusion, whereas the recombinant gp120 fragment did not. This shows that although glycosylation is not required for induction of neutralizing antibodies, it may be important for interaction with CD4, the virus receptor. A segment of the HTLV-III/LAV envelope produced in E. coli may be an important ingredient of a vaccine for acquired immune deficiency syndrome. 相似文献
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17.
Functional properties of antigen-specific T cells infected by human T-cell leukemia-lymphoma virus (HTLV-I) 总被引:14,自引:0,他引:14
H Mitsuya H G Guo J Cossman M Megson M S Reitz S Broder 《Science (New York, N.Y.)》1984,225(4669):1484-1486
Tetanus-toxoid specific helper-inducer T-cell clones, which had been infected and transformed by human T-cell leukemia-lymphoma virus (HTLV-I), were obtained from an antigen-specific human T cell line by using a limiting dilution technique in the presence of the virus. These HTLV-I-infected T-cell clones proliferated specifically in response to soluble tetanus toxoid but, unlike normal T cells, they could do so in the absence of accessory cells. The HTLV-I-infected T-cell clones did not present the antigen to autologous antigen-specific T cells that were not infected with HTLV-I. The capacity of helper-inducer T cells to retain antigen-specific reactivity after infection by HTLV-I, while losing the normal T-cell requirement for accessory cells, has clinical and theoretical implications. 相似文献
18.
Sequence homology and morphologic similarity of HTLV-III and visna virus, a pathogenic lentivirus 总被引:59,自引:0,他引:59
M A Gonda F Wong-Staal R C Gallo J E Clements O Narayan R V Gilden 《Science (New York, N.Y.)》1985,227(4683):173-177
A study was conducted of the genetic relation between human T-cell lymphotropic retroviruses and visna virus. The human T-cell lymphotropic viruses include those associated with T-cell malignancies (HTLV-I and HTLV-II) as well as the etiologic agent of the acquired immune deficiency syndrome (HTLV-III). Visna virus, a slowly replicating and pathogenic but nononcogenic retrovirus of sheep, is a member of the subfamily Lentivirinae. Results obtained by molecular hybridization and heteroduplex analysis indicated that a greater extent of nucleotide sequence homology exists between HTLV-III and visna virus than between HTLV-III and any of the other viruses. The homology observed under conditions of low stringency spanned the entire genome, but was strongest in the gag/pol region. The morphogenesis and fine structure of HTLV-III and visna virus also demonstrated striking similarities. The data provide strong evidence for a close taxonomic and thus evolutionary relation between HTLV-III and the Lentivirinae subfamily. 相似文献
19.
Detection, isolation, and continuous production of cytopathic retroviruses (HTLV-III) from patients with AIDS and pre-AIDS 总被引:450,自引:0,他引:450
A cell system was developed for the reproducible detection of human T-lymphotropic retroviruses (HTLV family) from patients with the acquired immunodeficiency syndrome (AIDS) or with signs or symptoms that frequently precede AIDS (pre-AIDS). The cells are specific clones from a permissive human neoplastic T-cell line. Some of the clones permanently grow and continuously produce large amounts of virus after infection with cytopathic (HTLV-III) variants of these viruses. One cytopathic effect of HTLV-III in this system is the arrangement of multiple nuclei in a characteristic ring formation in giant cells of the infected T-cell population. These structures can be used as an indicator to detect HTLV-III in clinical specimens. This system opens the way to the routine detection of HTLV-III and related cytopathic variants of HTLV in patients with AIDS or pre-AIDS and in healthy carriers, and it provides large amounts of virus for detailed molecular and immunological analyses. 相似文献
20.
Suramin protection of T cells in vitro against infectivity and cytopathic effect of HTLV-III 总被引:24,自引:0,他引:24
H Mitsuya M Popovic R Yarchoan S Matsushita R C Gallo S Broder 《Science (New York, N.Y.)》1984,226(4671):172-174