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1.
Arch Gynecol Obstet ; 296(4): 811-817, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28795241

RESUMO

PURPOSE: Few studies have described the epidemiology of human papillomavirus (HPV) in vulvar intraepithelial neoplasia (VIN). The aim of this study was to genotype HPV on formalin fixed paraffin-embedded tissues in VIN lesions. METHODS: A 5-year retrospective study was conducted by including all patients attending the teaching hospital of Nice with a diagnosis of VIN between 1st January 2010 and 31st December 2014. For all patients, HPV genotyping was performed with the PapilloCheck® microarray kit, routinely used on cervical cytology samples, and optimized for formaldehyde fixed paraffin-embedded tissues in VIN. RESULTS: Forty patients were included in the study: 39 patients had usual VIN and one presented with differentiated VIN. Among the 39 patients with usual VIN, the prevalence of HPV was 90% (35/39). Thirty-two patients had high grade VIN (82%) and seven low grade VIN (18%). In high grade VIN, the most represented HPV types were: HPV 16 (21/32 66%), HPV 56 (3/32 9%) and HPV 33 (2/32 6%). In low grade VIN, the most represented HPV types were: HPV 16 (4/7 57%) and HPV 6 (3/7 43%). Interestingly, 5/39 (13%) of patients diagnosed with usual VIN also had co-existing lichen sclerosus. CONCLUSIONS: We have optimized a HPV genotyping technique, routinely used on cervical cytology samples, and on paraffin fixed embedded tissue showing VIN. Moreover, we have identified five patients with lichen sclerosus co-existing with usual VIN. This association has rarely been reported and proves that these two entities can coexist.


Assuntos
Carcinoma in Situ/virologia , Papillomavirus Humano 16/genética , Papillomaviridae/genética , Infecções por Papillomavirus/virologia , Inclusão em Parafina , Neoplasias Vulvares/virologia , Adulto , Carcinoma in Situ/patologia , DNA Viral/análise , Feminino , Formaldeído , Genótipo , Humanos , Pessoa de Meia-Idade , Infecções por Papillomavirus/patologia , Estudos Retrospectivos , Neoplasias Vulvares/patologia
2.
Gynecol Obstet Fertil ; 42(10): 692-5, 2014 Oct.
Artigo em Francês | MEDLINE | ID: mdl-25281479

RESUMO

OBJECTIVES: Analysis of the distribution of human papillomavirus (HPV) genotypes amongst HIV-negative and HIV-positive women diagnosed with atypical squamous cells of undetermined significance (ASC-US). PATIENTS AND METHODS: We performed a retrospective study of HPV genotype distribution in 313 ASC-US Pap smears from women who consulted at the University Hospital of Nice between 2008 and 2012. HPV genotyping results, conducted on PapilloCheck(®) HPV DNA Chip, and information on the status of HIV patients were retrospectively collected. The odds ratio were calculated by logistic regression. RESULTS: In co-infected HIV/HPV women we observed a low prevalence of HPV16, a high prevalence of oncogenic HPV low risk and a high prevalence of HPV 68 compared to non-co-infected women. By grouping HPV HR based on their prevalence in cervical cancer of the uterus and their genetic proximity we observe that HPV 18, 45, 68 (the "alpha-7") are 7.4 times more represented (CI95 [2.48 to 22.35]) than HPV 16, 31, 33, 52, 58 (the "alpha-9") in the population of women co-infected with HIV. DISCUSSION AND CONCLUSION: Given that HPV "alpha-7" are responsible for 46.3% of adenocarcinomas, the high prevalence of these HPV found in ASC-US Pap smears of co-infected women should be put in relation with the highest prevalence of glandular abnormalities found in this population. HPV genotyping could become an essential tool for gynecological care for HIV positive women.


Assuntos
Células Escamosas Atípicas do Colo do Útero/virologia , Genótipo , Soronegatividade para HIV , Soropositividade para HIV/virologia , Papillomaviridae/genética , Adenocarcinoma/virologia , Alphapapillomavirus/genética , Coinfecção/virologia , Feminino , Infecções por HIV/virologia , Humanos , Papillomaviridae/classificação , Infecções por Papillomavirus/virologia , Estudos Retrospectivos , Neoplasias do Colo do Útero/virologia , Esfregaço Vaginal
3.
J Clin Virol ; 54(1): 76-8, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22336086

RESUMO

In European countries, epidemiology of hepatitis E virus (HEV) infection is not well known. Although, seroprevalence of HEV Immunoglobulin G reached a few percent in European women, no acute hepatitis E during pregnancy has been described so far. Here, we report a case of an autochthonous HEV genotype 3 infection in a 41-years-old pregnant woman living in a non-endemic country. The acute hepatitis had a spontaneous good outcome for the mother and the child. In non-endemic areas where Hepatitis E infections are emerging, unexplained cytolysis, whatever its level, in a pregnant woman could be investigated for HEV, using biological molecular and serology tools.


Assuntos
Vírus da Hepatite E/isolamento & purificação , Hepatite E/diagnóstico , Complicações Infecciosas na Gravidez/diagnóstico , RNA Viral/genética , Adulto , Feminino , França , Genótipo , Vírus da Hepatite E/classificação , Vírus da Hepatite E/genética , Humanos , Lactente , Recém-Nascido , Gravidez , Resultado do Tratamento
4.
Virologie (Montrouge) ; 11(4): 289-296, 2007 Aug 01.
Artigo em Francês | MEDLINE | ID: mdl-36131476

RESUMO

The curvature of host cell membranes during the budding of HIV viruses occurs by an opposite topology, as compared to endocytosis and phagocytosis phenomena. This topology of vesicle formation is indeed observed during the formation of internal vesicles of late endosomal compartments called multivesicular bodies (MVB). Formation of these vesicles is controlled by ubiquitylation and the recruitment of the endosomal sorting complex required for transport (ESCRT). The sorting of HIV-1 structural protein Pr55gag into the viral bud requires the recruitment of the ESCRT complex, potentiated by Pr55gag ubiquitylation. Interestingly, in response to viral infection, type I interferon triggers the expression of the ubiquitin-like polypeptide ISG15 which then inhibits the recruitment of the ESCRT machinery by inhibiting Pr55gag ubiquitylation.

6.
C R Acad Sci III ; 324(12): 1125-32, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11803813

RESUMO

In vitro, LSLCL is expressed by numerous myeloid, promyelocytic, and T or B lymphoblastoid cell lines. In vivo, LSLCL is strongly expressed in bone marrow and only faintly in lymphoid organs. We show here that, in bone marrow, LSLCL is detected: (i) concentrated in the cytoplasm of immature neutrophils but not in myeloblasts nor in mature neutrophils, (ii) in extracellular bone marrow fluid. Besides, numerous cDNAs, similar to LSLCL (identity of 93-99%), are found in 'expressed sequence tags' databases from various origins, mostly fetal and undifferentiated tumour tissues. Since LSLCL and various closely related cDNAs are expressed at definite stages of cellular maturation processes, we hypothesize that this class of proteins could play an important role in the control of cellular differentiation.


Assuntos
Regulação da Expressão Gênica , Fatores de Crescimento de Células Hematopoéticas , Lectinas Tipo C , Lectinas/genética , Neutrófilos/fisiologia , Animais , Northern Blotting , Células da Medula Óssea/citologia , Células da Medula Óssea/fisiologia , Galinhas , Bases de Dados de Ácidos Nucleicos , Etiquetas de Sequências Expressas , Feminino , Doenças Hematológicas/sangue , Doenças Hematológicas/genética , Humanos , Lectinas/sangue , Leucemia/sangue , Leucemia/genética , Neutrófilos/citologia
9.
J Biol Chem ; 273(4): 1911-6, 1998 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-9442024

RESUMO

We have previously demonstrated hyposialylation of the two major CD45 and leukosialin (CD43) molecules at the surface of latently human immunodeficiency virus type 1-infected CEM T cells (CEMLAI/NP), (Lefebvre, J. C., Giordanengo, V., Doglio, A., Cagnon, L., Breittmayer, J. P., Peyron, J. F., and Lesimple, J. (1994) Virology 199, 265-274; Lefebvre, J. C., Giordanengo, V., Limouse, M., Doglio, A., Cucchiarini, M., Monpoux, F., Mariani, R., and Peyron, J. F. (1994) J. Exp. Med. 180, 1609-1617). Searching to clarify mechanism(s) of hyposialylation, we observed two sulfated secreted glycoproteins (molecular mass approximately 47 and approximately 40 kDa) (P47 and P40), which were differentially sulfated and/or differentially secreted in the culture supernatants of CEMLAI/NP cells when compared with parental CEM cells. A hybridoma clone (7H1) resulting from the fusion between CEMLAI/NP and human embryonic fibroblasts MRC5 cells produced very large amounts of P47 that was purified using Jacalin lectin (specific for O-glycans) and microsequenced. Cloning of P47 was achieved using a CEMLAI/NP cDNA library screened with a degenerate oligonucleotide probe based on its NH2-terminal amino acid sequence. A single open reading frame encoding a protein of 323 amino acids was deduced from the longest isolated recombinant (1.4 kilobase). P47 is a secreted sulfated protein. It carries an NH2-terminal RGD (Arg-Gly-Asp) triplet, a striking alpha-helical leucine zipper composed of six heptads, and a C-terminal C-type lectin domain. The NH2-terminal portion is rich in glutamic acids with a predicted pI of 3.9. In addition, a hinge region with numerous condensed potential sites for O-glycan side chains, which are also the most likely sulfation sites, is located between the RGD and leucine zipper domains. Transcripts were detected in lymphoid tissues (notably bone marrow) and abundantly in T and B lymphoblastoid but very faintly in monocytoid cell lines.


Assuntos
Antígenos CD , Fatores de Crescimento de Células Hematopoéticas , Lectinas Tipo C , Lectinas/genética , Ativação Linfocitária , Linfócitos T/química , Sequência de Aminoácidos , Animais , Biomarcadores Tumorais , Proteínas Sanguíneas/química , Clonagem Molecular , Glicosilação , Infecções por HIV/metabolismo , HIV-1 , Células HL-60 , Humanos , Células Jurkat , Lectinas/química , Zíper de Leucina , Antígenos Comuns de Leucócito/química , Leucossialina , Dados de Sequência Molecular , Peso Molecular , Proteína Tirosina Fosfatase não Receptora Tipo 1 , Coelhos , Receptores de IgE/química , Alinhamento de Sequência , Sialoglicoproteínas/química , Linfócitos T/virologia
10.
Clin Exp Immunol ; 110(1): 22-5, 1997 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9353144

RESUMO

In previous studies, we have demonstrated that O-glycans at the surface of HIV-1-infected cell lines were hyposialylated. Moreover, we and others have shown that HIV+ individuals produced autoantibodies that react with hyposialylated CD43, on T cell lines. Since the autoantigen responsible for this abnormal immune response was not easily found in the peripheral blood cells of corresponding patients, we searched for its possible presence in other sites. Using fluorescence staining of alveolar macrophages with various lectins, we show that the binding of the PNA lectin specific for asialo O-glycans is much more efficient on cells from HIV-1-infected individuals. Moreover, the degree of reactivity of PNA is correlated with the clinical stage of the illness.


Assuntos
Infecções por HIV/imunologia , HIV-1 , Macrófagos Alveolares/metabolismo , Polissacarídeos/metabolismo , Adulto , Infecções por HIV/patologia , Humanos , Lectinas/metabolismo , Macrófagos Alveolares/imunologia , Pessoa de Meia-Idade , Ácido N-Acetilneuramínico
11.
Eur J Biochem ; 247(2): 558-66, 1997 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-9266697

RESUMO

Complementary DNA encoding a human Gal(beta1-3)GalNAc alpha2,3-sialyltransferase type II (hST3Gal II) was cloned from a CEM T-cell cDNA library using a 23-base oligonucleotide probe. The sequence of this probe was established on the basis of a slightly divergent sialylmotif L that was obtained by polymerase chain reaction with degenerate oligonucleotide primers based on the conserved sialylmotif L of mammalian Gal(beta1-3)GalNAc alpha2,3-sialyltransferases. It was thus confirmed that a short oligonucleotide probe may be sensitive and highly specific. The nucleotide and amino acid sequences of hST3Gal II show, respectively, 56.3% and 49.3% similarity to hST3Gal I [Kitagawa, H. & Paulson, J. C. (1994) J. Biol. Chem. 269, 17872-17878] and 88.1% and 93.7% similarity to murine ST3Gal II [Lee, Y. C., Kojima, N., Wada, E., Kurosawa, N., Nakaoka, T., Hamamoto, T. & Tsuji, S. (1994) J. Biol. Chem. 269, 10028-10033]. hST3Gal II mRNA was highly expressed in heart, liver, skeletal muscle and various lymphoid tissues but not in brain and kidney. A soluble form of hST3Gal II expressed in COS-7 cells was tested in vitro for substrate specificity and kinetic properties. Asialofetuin and asialo-bovine submaxillary mucin appeared better substrates for hST3Gal II than for its murine counterpart as previously reported [Kojima, N., Lee, Y.-C., Hamamoto, T., Kurosawa, N. & Tsuji, S. (1994) Biochemistry 33, 5772-5776]. In previous studies, we have shown hyposialylation of O-glycans attached to two major lymphocyte CD43 and CD45 cell surface molecules in human-immunodeficiency-virus-1(HIV-1)-infected T-cell lines. Since comparable levels of hST3Gal I and hST3Gal II mRNA and enzymatic activity were observed in parental and HIV-1-infected CEM T-cell lysates, the sialylation defect associated with HIV infection of this cell line is probably due to a mechanism different from a simple altered catalytic activity of these sialyltransferases.


Assuntos
Sialiltransferases/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Células COS , Linhagem Celular , Primers do DNA , DNA Complementar , Humanos , Cinética , Dados de Sequência Molecular , Especificidade de Órgãos , Reação em Cadeia da Polimerase , RNA Mensageiro/biossíntese , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Sialiltransferases/biossíntese , Sialiltransferases/química , Linfócitos T , Transfecção
12.
AIDS Res Hum Retroviruses ; 12(17): 1615-22, 1996 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-8947296

RESUMO

CD44 is known to interfere in HIV replication and to participate in many physiological processes such as lymphocyte binding to high endothelial venules of lymphoid tissue, lymph nodes, and mucosal endothelium. The T cell lines MOLT-4 and CEM, and CEM subclones were infected with the HIV-1 LAI strain and monitored for the expression of CD44 during the course of chronic virus production until the infected cells were at the stage of latent infection. The levels of CD44 protein expression were quantified using cell surface immunostaining and biotinylation. The maturation of CD44 molecules was evaluated by metabolic sulforadiolabeling and CD44 mRNA was visualized by Northern blot analysis. We show a downmodulation of CD44 expression in infected T cell lines and subclones. This phenomenon was most evident at the stage of latent infection. Then, CD44 molecules were undetectable at both the protein and mRNA levels in latently infected CEM cells and CEM subclones. In addition, the 97-kDa standard CD44 isoform showed a shift upward, while detectable during the stage of chronic virus production. In latently infected MOLT-4 cells, the CD44 protein levels were dramatically decreased; CD44 mRNA was detected, but the sizes differed from the mRNA in uninfected cells. Since CD44 is known to regulate in part lymphocyte homing and HIV replication, the alterations that were observed in the expression of this molecule could interfere with the particular homing of HIV-infected cells and/or viral latency.


Assuntos
Processamento Alternativo , Regulação da Expressão Gênica , HIV-1/fisiologia , Receptores de Hialuronatos/genética , Linfócitos T/imunologia , Biotina , Linhagem Celular , Membrana Celular/imunologia , Humanos , Receptores de Hialuronatos/imunologia , RNA Mensageiro , Solubilidade , Sulfatos , Linfócitos T/citologia , Células Tumorais Cultivadas
13.
Blood ; 86(6): 2302-11, 1995 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-7662977

RESUMO

Autoantibodies to lymphocytes have been detected in sera from human immunodeficiency virus type 1 (HIV-1)-infected individuals, and several autoantigens have been described. Among them, hyposialylated CD43 has been shown to be a target for autoantibodies in up to 47% of HIV+ individuals. However, the corresponding autoantigen (ie, the incompletely sialylated CD43) has not been isolated from blood cells of HIV-1-infected individuals. Recently, we have observed in vitro that HIV-1 productively or latently infected CEM cells (CEMLAI/NP) express CD43 molecules with modified glycosylation (mogly CD43). Using CEMLAI/NP cells, which do not express any structural viral antigen, we show now that all of the tested HIV+ sera from asymptomatic individuals, and up to 86% of those from subjects at the acquired immunodeficiency syndrome stage contain antibodies (mainly IgM and, to a lesser degree, IgG) that recognize the surface of CEMLAI/NP cells, and precipitate mogly CD43 molecules from the cells lysates. Taken together with our previous demonstration of altered glycosylation of CD43 from HIV-1-infected CEM cells in vitro, the constant antimogly CD43 autoimmune response observed from asymptomatic HIV-1+ subjects is likely to illustrate the occurrence of an altered glycosylation in vivo of the major lymphocyte surface CD43 glycoprotein, associated with HIV-1 infection.


Assuntos
Antígenos CD , Autoanticorpos/imunologia , Autoantígenos/imunologia , Infecções por HIV/imunologia , HIV-1 , Sialoglicoproteínas/imunologia , Linfócitos T/imunologia , Síndrome da Imunodeficiência Adquirida/imunologia , Artrite Reumatoide/imunologia , Autoantígenos/química , Linhagem Celular , Reações Cruzadas , Glicosilação , Hepatite B/imunologia , Humanos , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Leucossialina , Lúpus Eritematoso Sistêmico/imunologia , Peso Molecular , Ácido N-Acetilneuramínico , Ácidos Siálicos/análise , Sialoglicoproteínas/química , Linfócitos T/virologia
14.
Artigo em Inglês | MEDLINE | ID: mdl-7697438

RESUMO

HIV-1 appears to use a multiple gene strategy to regulate CD4 receptor expression, which emphasizes the importance of this regulation in the viral life cycle. The cytoplasmic interaction between gp160 and CD4 is probably the major event governing CD4 down-regulation, although other viral proteins, such as Nef (CD4 cell surface localization) and Vpu (CD4 degradation), are thought to participate as well. Because of the lack of vpu in HIV-2, we investigated the effects of two HIV-2 isolates (ROD 10 and EHO) on CD4 expression in the CEM T-cell line. We found that these HIV-2 strains induce CD4 degradation to a similar extent as that induced by an HIV-1 isolate (BRU). To assess the role of each viral protein involved in CD4 regulation (gp, Nef and Vpu), we developed cell lines expressing a mutated form of CD4 unable to efficiently bind gp160, in addition to their endogenous CD4. Using this system, we provide evidence that the mutated CD4 is always expressed in HIV-1-, and HIV-2-infected cells, independent of the presence of Nef, while the endogenous CD4 is completely lost. These results highlight the key role of intracytoplasmic gp-CD4 interaction, explaining in vitro the CD4 down-regulation in T-cell lines.


Assuntos
Antígenos CD4/metabolismo , Regulação para Baixo/genética , Produtos do Gene env/metabolismo , HIV-1/metabolismo , HIV-2/metabolismo , Precursores de Proteínas/metabolismo , Sequência de Bases , Western Blotting , Antígenos CD4/genética , Linhagem Celular , Primers do DNA/química , Ensaio de Imunoadsorção Enzimática , Regulação Viral da Expressão Gênica/genética , Produtos do Gene nef/genética , Produtos do Gene nef/fisiologia , Proteína gp120 do Envelope de HIV/metabolismo , Proteína gp160 do Envelope de HIV , HIV-1/genética , HIV-1/fisiologia , HIV-2/genética , HIV-2/fisiologia , Proteínas do Vírus da Imunodeficiência Humana , Humanos , Dados de Sequência Molecular , Mutação , Reação em Cadeia da Polimerase , Proteínas Virais Reguladoras e Acessórias/genética , Proteínas Virais Reguladoras e Acessórias/fisiologia , Replicação Viral , Produtos do Gene env do Vírus da Imunodeficiência Humana , Produtos do Gene nef do Vírus da Imunodeficiência Humana
15.
Eur J Immunol ; 25(1): 274-8, 1995 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-7843243

RESUMO

CD43 is a major heavily glycosylated lymphocyte surface molecule. It has been shown to play an important role in lymphocyte activation and cell-cell interactions. Here we demonstrate that in human activated lymphocytes and CEM T cells, CD43 is a sulfated molecule. We also observed that CD45, another lymphocyte surface glycoprotein, is a sulfated molecule. 35SO4(2-) incorporation would thus appear to be an appropriate labeling method for CD43 and CD45 visualization. Moreover, we show that the level of cell surface protein sulfation can modulate CD43-mediated homotypic aggregation induced by CD43 monoclonal antibodies. It is well known that glycoprotein sulfation is required for various recognition phenomena. Since there are numerous potential sulfation sites on CD43 and CD45, these residues could play an important role in regulating cell-cell interactions.


Assuntos
Antígenos CD/química , Adesão Celular/imunologia , Antígenos Comuns de Leucócito/química , Linfócitos/imunologia , Sialoglicoproteínas/química , Sulfatos/análise , Anticorpos Monoclonais/imunologia , Antígenos CD/imunologia , Linhagem Celular , Humanos , Antígenos Comuns de Leucócito/imunologia , Leucossialina , Sialoglicoproteínas/imunologia , Relação Estrutura-Atividade
16.
J Exp Med ; 180(5): 1609-17, 1994 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-7964449

RESUMO

CD43 (leukosialin, gpL115, sialophorin) is a major sialoglycoprotein widely expressed on hematopoietic cells that is defective in the congenital immunodeficiency Wiskott-Aldrich syndrome. It is thought to play an important role in cell-cell interactions and to be a costimulatory molecule for T lymphocyte activation. Using a metabolic 35SO4(2-) radiolabeling assay or biotinylation of cell surface proteins, we describe here that CD43 are sulfated molecules the glycosylation of which is altered in human immunodeficiency virus type 1 (HIV-1)-infected leukemic T cells of the CEM line. Hyposialylation of O-glycans and changed substitution on N-acetylgalactosamine residues are observed. The glycosylation defect is associated with an impairment of CD43-mediated homotypic aggregation which can be restored by resialylation. The hyposialylation of CD43 on HIV-1+ cells may explain the high prevalence of autoantibodies directed against nonsialylated CD43 that have been detected in HIV-1-infected individuals. A defect in glycosylation of important molecules such as CD43 or, as we recently described, CD45 may explain alterations of T cell functions and viability in HIV-1-infected individuals. In addition, a possible implication of hyposialylation in the HIV-1-infected cells entrapment in lymph nodes could be envisioned.


Assuntos
Antígenos CD , HIV-1/fisiologia , Sialoglicoproteínas/metabolismo , Anticorpos Monoclonais/imunologia , Autoimunidade , Agregação Celular , Linhagem Celular , Glicosilação , Humanos , Leucossialina , Peso Molecular , Ácido N-Acetilneuramínico , Ácidos Siálicos/metabolismo , Sialoglicoproteínas/análise , Sialoglicoproteínas/química , Linfócitos T/imunologia
17.
Virology ; 199(2): 265-74, 1994 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8122360

RESUMO

Immunodeficiency caused by HIV infection probably results from profound dysregulation of normal T lymphocyte properties by the virus. Despite description of the virus cytopathicity and numerous modifications in T cell functions, such as perturbation of antigen receptor signaling, CD4 downregulation, and induction of apoptosis, the precise mechanisms underlying the disruption of normal immune responses have not yet been elucidated. In the present study, we show that HIV-1-infected lymphocytes of the CEM cell line (either latent or virus-producing) and HIV-1-infected CD4+ lymphocytes have several membrane proteins with altered glycosylation patterns. Using lectins with specificity for different carbohydrate moieties, we could demonstrate the presence of two exposed nonsialylated disaccharides: a terminal Gal beta 1-->3GalNAc and a terminal Gal beta 1-->4GlcNAc. In particular, CD45, one of the major T cell glycoproteins, appeared to be partially sialylated on N- and O-linked carbohydrate moieties. Concerning the latter, PNA lectin which recognizes nonsialylated terminal Gal beta 1-->3GalNAc might precipitate up to 75% of the total tyrosine phosphatase activity displayed by CD45 molecules from one latently HIV-1-infected CEM cell line. Since CD45 glycoproteins are thought to play an important regulatory role in cell-to-cell interactions owing to their variable extracellular region and because they may regulate membrane signaling through their intracellular phosphatase domains, we suggest that these altered CD45 molecules may present an abnormal signal for natural ligands such as the B-cell-specific surface receptor CD22, thus perturbing the normal immune response in HIV-1-infected individuals.


Assuntos
HIV-1 , Antígenos Comuns de Leucócito/biossíntese , Sialoglicoproteínas/biossíntese , Linfócitos T/metabolismo , Linfócitos T/microbiologia , Sequência de Carboidratos , Células Cultivadas , Glicosilação , Antígenos Comuns de Leucócito/metabolismo , Dados de Sequência Molecular , Proteínas Tirosina Fosfatases/metabolismo , Sialoglicoproteínas/metabolismo
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