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1.
Sci Immunol ; 3(30)2018 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-30578351

RESUMO

Hundreds of patients with autosomal recessive, complete IL-12p40 or IL-12Rß1 deficiency have been diagnosed over the last 20 years. They typically suffer from invasive mycobacteriosis and, occasionally, from mucocutaneous candidiasis. Susceptibility to these infections is thought to be due to impairments of IL-12-dependent IFN-γ immunity and IL-23-dependent IL-17A/IL-17F immunity, respectively. We report here patients with autosomal recessive, complete IL-12Rß2 or IL-23R deficiency, lacking responses to IL-12 or IL-23 only, all of whom, unexpectedly, display mycobacteriosis without candidiasis. We show that αß T, γδ T, B, NK, ILC1, and ILC2 cells from healthy donors preferentially produce IFN-γ in response to IL-12, whereas NKT cells and MAIT cells preferentially produce IFN-γ in response to IL-23. We also show that the development of IFN-γ-producing CD4+ T cells, including, in particular, mycobacterium-specific TH1* cells (CD45RA-CCR6+), is dependent on both IL-12 and IL-23. Last, we show that IL12RB1, IL12RB2, and IL23R have similar frequencies of deleterious variants in the general population. The comparative rarity of symptomatic patients with IL-12Rß2 or IL-23R deficiency, relative to IL-12Rß1 deficiency, is, therefore, due to lower clinical penetrance. There are fewer symptomatic IL-23R- and IL-12Rß2-deficient than IL-12Rß1-deficient patients, not because these genetic disorders are rarer, but because the isolated absence of IL-12 or IL-23 is, in part, compensated by the other cytokine for the production of IFN-γ, thereby providing some protection against mycobacteria. These experiments of nature show that human IL-12 and IL-23 are both required for optimal IFN-γ-dependent immunity to mycobacteria, both individually and much more so cooperatively.


Assuntos
Imunidade Inata/imunologia , Interferon gama/imunologia , Interleucina-12/imunologia , Interleucina-23/imunologia , Infecções por Micobactéria não Tuberculosa/imunologia , Mycobacterium/imunologia , Humanos , Interleucina-12/deficiência , Interleucina-12/genética , Interleucina-23/deficiência , Interleucina-23/genética , Linhagem
2.
Nature ; 562(7725): 63-68, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30232458

RESUMO

Narcolepsy is a chronic sleep disorder caused by the loss of neurons that produce hypocretin. The close association with HLA-DQB1*06:02, evidence for immune dysregulation and increased incidence upon influenza vaccination together suggest that this disorder has an autoimmune origin. However, there is little evidence of autoreactive lymphocytes in patients with narcolepsy. Here we used sensitive cellular screens and detected hypocretin-specific CD4+ T cells in all 19 patients that we tested; T cells specific for tribbles homologue 2-another self-antigen of hypocretin neurons-were found in 8 out of 13 patients. Autoreactive CD4+ T cells were polyclonal, targeted multiple epitopes, were restricted primarily by HLA-DR and did not cross-react with influenza antigens. Hypocretin-specific CD8+ T cells were also detected in the blood and cerebrospinal fluid of several patients with narcolepsy. Autoreactive clonotypes were serially detected in the blood of the same-and even of different-patients, but not in healthy control individuals. These findings solidify the autoimmune aetiology of narcolepsy and provide a basis for rapid diagnosis and treatment of this disease.

3.
Nat Immunol ; 19(9): 973-985, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30127434

RESUMO

Human inborn errors of IFN-γ immunity underlie mycobacterial diseases. We describe patients with Mycobacterium bovis (BCG) disease who are homozygous for loss-of-function mutations of SPPL2A. This gene encodes a transmembrane protease that degrades the N-terminal fragment (NTF) of CD74 (HLA invariant chain) in antigen-presenting cells. The CD74 NTF therefore accumulates in the HLA class II+ myeloid and lymphoid cells of SPPL2a-deficient patients. This toxic fragment selectively depletes IL-12- and IL-23-producing CD1c+ conventional dendritic cells (cDC2s) and their circulating progenitors. Moreover, SPPL2a-deficient memory TH1* cells selectively fail to produce IFN-γ when stimulated with mycobacterial antigens in vitro. Finally, Sppl2a-/- mice lack cDC2s, have CD4+ T cells that produce small amounts of IFN-γ after BCG infection, and are highly susceptible to infection with BCG or Mycobacterium tuberculosis. These findings suggest that inherited SPPL2a deficiency in humans underlies mycobacterial disease by decreasing the numbers of cDC2s and impairing IFN-γ production by mycobacterium-specific memory TH1* cells.

4.
PLoS One ; 12(11): e0187731, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29112951

RESUMO

Congenital human cytomegalovirus (HCMV) infection is the major cause of birth defects and a precise definition of the HCMV-specific T-cell response in primary infection may help define reliable correlates of immune protection during pregnancy. In this study, a high throughput method was used to define the frequency of CD4+ and CD8+ T cells specific for four HCMV proteins in the naïve compartment of seronegative subjects and the effector/memory compartments of subjects with primary/remote HCMV infection. The naïve repertoire displayed comparable frequencies of T cells that were reactive with HCMV structural (pp65, gB and the pentamer gHgLpUL128L) and non-structural (IE-1) proteins. Whereas, following natural infection, the majority of effector/memory CD4+ and CD8+ T cells recognized either gB or IE-1, respectively, and pp65. The pattern of T cell reactivity was comparable at early and late stages of infection and in pregnant women with primary HCMV infection transmitting or not transmitting the virus to the fetus. At an early stage of primary infection, about 50% of HCMV-reactive CD4+ T cells were long-term IL-7Rpos memory cells, while 6-12 months later, the frequency of these cells increased to 70%, approaching 100% in remote infections. In contrast, only 10-20% of HCMV-specific CD8+ T cells were long-term memory cells up to 12 months after infection onset, thereafter increasing to 70% in remote infections. Interestingly, a significantly higher frequency of HCMV-specific CD4+ T cells with a long-term IL-7Rpos memory phenotype was observed in non-transmitting compared to transmitting women. These findings indicate that immunodominance in HCMV infection is not predetermined in the naïve compartment, but is the result of virus-host interactions and suggest that prompt control of HCMV infection in pregnancy is associated with the rapid development of long-term IL-7Rpos memory HCMV-specific CD4+ T cells and a low risk of virus transmission to the fetus.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Infecções por Citomegalovirus/imunologia , Memória Imunológica , Imunofenotipagem , Transmissão Vertical de Doença Infecciosa/prevenção & controle , Complicações Infecciosas na Gravidez/prevenção & controle , Feminino , Humanos , Gravidez
6.
Science ; 353(6301): 823-6, 2016 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-27417494

RESUMO

Zika virus (ZIKV), a mosquito-borne flavivirus with homology to Dengue virus (DENV), has become a public health emergency. By characterizing memory lymphocytes from ZIKV-infected patients, we dissected ZIKV-specific and DENV-cross-reactive immune responses. Antibodies to nonstructural protein 1 (NS1) were largely ZIKV-specific and were used to develop a serological diagnostic tool. In contrast, antibodies against E protein domain I/II (EDI/II) were cross-reactive and, although poorly neutralizing, potently enhanced ZIKV and DENV infection in vitro and lethally enhanced DENV disease in mice. Memory T cells against NS1 or E proteins were poorly cross-reactive, even in donors preexposed to DENV. The most potent neutralizing antibodies were ZIKV-specific and targeted EDIII or quaternary epitopes on infectious virus. An EDIII-specific antibody protected mice from lethal ZIKV infection, illustrating the potential for antibody-based therapy.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Infecção por Zika virus/imunologia , Zika virus/imunologia , Animais , Anticorpos Monoclonais/química , Anticorpos Monoclonais/uso terapêutico , Anticorpos Neutralizantes/química , Anticorpos Neutralizantes/uso terapêutico , Anticorpos Antivirais/química , Anticorpos Antivirais/uso terapêutico , Especificidade de Anticorpos , Reações Cruzadas , Vírus da Dengue/imunologia , Modelos Animais de Doenças , Humanos , Epitopos Imunodominantes/imunologia , Memória Imunológica , Estrutura Terciária de Proteína , Linfócitos T/imunologia , Proteínas do Envelope Viral/imunologia , Proteínas não Estruturais Virais/imunologia , Infecção por Zika virus/prevenção & controle , Infecção por Zika virus/terapia
7.
J Gen Virol ; 97(8): 1928-41, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27113912

RESUMO

Analysis of human cytomegalovirus (HCMV) primary infection in immunocompetent (n=40) and immunocompromised transplant patients (n=20) revealed that the median peak antibody titre neutralizing infection of epithelial cells was 16-fold higher in immunocompromised patients. The mechanism of this finding was investigated by measuring: (i) HCMV DNAemia; (ii) HCMV neutralizing antibodies; (iii) ELISA IgG antibody titre to HCMV glycoprotein complexes gHgLpUL128L, gHgLgO and gB; and (iv) HCMV-specific (IFN-γ+) CD4+ and CD8+ T-cells. Circulating CXCR5+ CD4+ (memory T follicular helper - TFH-cells) were identified as activated TFH (ICOS+PD-1++CCR7lo) and quiescent cells. In the early stages of primary infection, activated TFH cells increased in number. Concomitantly, both neutralizing and IgG antibodies to HCMV glycoproteins reached a peak, followed by a plateau. A stop in antibody rise occurred upon appearance of HCMV-specific CD4+ T-cells, HCMV clearance and progressive reduction in activated TFH cells. The main differences between healthy and transplant patients were that the latter had a delayed DNA peak, a much higher DNA load and delayed activated TFH cells and antibody peaks. Similar events were observed in clinically severe HCMV reactivations of transplant patients. A preliminary analysis of the specificity of the activated TFH cell response to viral proteins showed a major response to the pentamer gHgLpUL128L and gB. In conclusion, in the absence of T-cell immunity, one of the first lines of defence, during primary infection, is conferred by antibodies produced through the interaction of TFH cells and B-cells of germinal centres, resulting in differentiation of B-cells into antibody producing plasma cells.


Assuntos
Anticorpos Antivirais/sangue , Formação de Anticorpos , Citomegalovirus/imunologia , Centro Germinativo/citologia , Linfócitos T Auxiliares-Indutores/imunologia , Transplantados , Anticorpos Neutralizantes/sangue , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Infecções por Citomegalovirus/imunologia , DNA Viral/sangue , Ensaio de Imunoadsorção Enzimática , Humanos , Hospedeiro Imunocomprometido , Imunoglobulina G/sangue , Testes de Neutralização , Carga Viral , Viremia
8.
Science ; 349(6248): 606-613, 2015 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-26160376

RESUMO

Human inborn errors of immunity mediated by the cytokines interleukin-17A and interleukin-17F (IL-17A/F) underlie mucocutaneous candidiasis, whereas inborn errors of interferon-γ (IFN-γ) immunity underlie mycobacterial disease. We report the discovery of bi-allelic RORC loss-of-function mutations in seven individuals from three kindreds of different ethnic origins with both candidiasis and mycobacteriosis. The lack of functional RORγ and RORγT isoforms resulted in the absence of IL-17A/F-producing T cells in these individuals, probably accounting for their chronic candidiasis. Unexpectedly, leukocytes from RORγ- and RORγT-deficient individuals also displayed an impaired IFN-γ response to Mycobacterium. This principally reflected profoundly defective IFN-γ production by circulating γδ T cells and CD4(+)CCR6(+)CXCR3(+) αß T cells. In humans, both mucocutaneous immunity to Candida and systemic immunity to Mycobacterium require RORγ, RORγT, or both.


Assuntos
Candida albicans/imunologia , Candidíase Mucocutânea Crônica/genética , Imunidade/genética , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Imunodeficiência Combinada Severa/genética , Tuberculose Bovina/genética , Tuberculose Pulmonar/genética , Alelos , Animais , Candidíase Mucocutânea Crônica/complicações , Candidíase Mucocutânea Crônica/imunologia , Bovinos , Criança , Pré-Escolar , Análise Mutacional de DNA , Exoma/genética , Feminino , Rearranjo Gênico da Cadeia alfa dos Receptores de Antígenos dos Linfócitos T , Humanos , Interferon gama/imunologia , Interleucina-17/imunologia , Camundongos , Mutação , Mycobacterium bovis/imunologia , Mycobacterium bovis/isolamento & purificação , Mycobacterium tuberculosis/imunologia , Mycobacterium tuberculosis/isolamento & purificação , Linhagem , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/genética , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Linfócitos T/imunologia , Timo/anormalidades , Timo/imunologia , Tuberculose Bovina/imunologia , Tuberculose Pulmonar/imunologia
9.
Nat Commun ; 6: 6431, 2015 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-25775432

RESUMO

T helper (TH) cell polarization during priming is modulated by a number of signals, but whether polarization to a given phenotype also influences recall responses of memory TH cells is relatively unknown. Here we show that miR-181a is selectively induced in both human and mouse naive T cells differentiating into the TH17, but not TH1 or TH2 subset. In human memory TH17 cells, miR-181a regulates responses to cognate antigens through modulation of ERK phosphorylation. By enhancing the signalling cascade from the T-cell receptor, such molecular network reduces the threshold of TH17 cell activation. Moreover, at a late time point, the same network induces a self-regulatory mechanism dependent on ID3, a negative regulator of transcription factors that control RORC expression, thus modulating TH17 activity. Our results demonstrate that the phenotype acquired by TH cells during priming contributes to their threshold of activation to secondary antigenic stimulations, thus influencing memory responses.


Assuntos
MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Memória Imunológica , MicroRNAs/metabolismo , Células Th17/citologia , Animais , Antígenos/química , Candida albicans/metabolismo , Diferenciação Celular , Feminino , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , MicroRNAs/genética , Fenótipo , Fosforilação , Interferência de RNA , Transdução de Sinais
10.
Science ; 347(6220): 400-6, 2015 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-25477212

RESUMO

Distinct types of CD4(+) T cells protect the host against different classes of pathogens. However, it is unclear whether a given pathogen induces a single type of polarized T cell. By combining antigenic stimulation and T cell receptor deep sequencing, we found that human pathogen- and vaccine-specific T helper 1 (T(H)1), T(H)2, and T(H)17 memory cells have different frequencies but comparable diversity and comprise not only clones polarized toward a single fate, but also clones whose progeny have acquired multiple fates. Single naïve T cells primed by a pathogen in vitro could also give rise to multiple fates. Our results unravel an unexpected degree of interclonal and intraclonal functional heterogeneity of the human T cell response and suggest that polarized responses result from preferential expansion rather than priming.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Candida albicans/imunologia , Interações Hospedeiro-Patógeno/imunologia , Memória Imunológica , Mycobacterium tuberculosis/imunologia , Subpopulações de Linfócitos T/imunologia , Vacinas/imunologia , Sequência de Aminoácidos , Células Cultivadas , Células Clonais , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Ativação Linfocitária , Dados de Sequência Molecular , Receptores de Antígenos de Linfócitos T/genética , Células Th1/imunologia , Células Th17/imunologia , Células Th2/imunologia
11.
Proc Natl Acad Sci U S A ; 112(2): E147-55, 2015 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-25548174

RESUMO

A previous unbiased genome-wide analysis of CD4 Mycobacterium tuberculosis (MTB) recognition using peripheral blood mononuclear cells from individuals with latent MTB infection (LTBI) or nonexposed healthy controls (HCs) revealed that certain MTB sequences were unexpectedly recognized by HCs. In the present study, it was found that, based on their pattern of reactivity, epitopes could be divided into LTBI-specific, mixed reactivity, and HC-specific categories. This pattern corresponded to sequence conservation in nontuberculous mycobacteria (NTMs), suggesting environmental exposure as an underlying cause of differential reactivity. LTBI-specific epitopes were found to be hyperconserved, as previously reported, whereas the opposite was true for NTM conserved epitopes, suggesting that intragenus conservation also influences host pathogen adaptation. The biological relevance of this observation was demonstrated further by several observations. First, the T cells elicited by MTB/NTM cross-reactive epitopes in HCs were found mainly in a CCR6(+)CXCR3(+) memory subset, similar to findings in LTBI individuals. Thus, both MTB and NTM appear to elicit a phenotypically similar T-cell response. Second, T cells reactive to MTB/NTM-conserved epitopes responded to naturally processed epitopes from MTB and NTMs, whereas T cells reactive to MTB-specific epitopes responded only to MTB. Third, cross-reactivity could be translated to antigen recognition. Several MTB candidate vaccine antigens were cross-reactive, but others were MTB-specific. Finally, NTM-specific epitopes that elicit T cells that recognize NTMs but not MTB were identified. These epitopes can be used to characterize T-cell responses to NTMs, eliminating the confounding factor of MTB cross-recognition and providing insights into vaccine design and evaluation.


Assuntos
Antígenos de Bactérias/genética , Antígenos de Bactérias/imunologia , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/imunologia , Adulto , Sequência de Aminoácidos , Estudos de Casos e Controles , Sequência Conservada , Reações Cruzadas , Genoma Bacteriano , Estudo de Associação Genômica Ampla , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Humanos , Tuberculose Latente/genética , Tuberculose Latente/imunologia , Tuberculose Latente/microbiologia , Dados de Sequência Molecular , Micobactérias não Tuberculosas/genética , Micobactérias não Tuberculosas/imunologia , Receptores CCR6/metabolismo , Receptores CXCR3/metabolismo , Especificidade da Espécie , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/microbiologia , Vacinas contra a Tuberculose/genética , Vacinas contra a Tuberculose/imunologia
12.
PLoS Pathog ; 9(1): e1003130, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23358848

RESUMO

An understanding of the immunological footprint of Mycobacterium tuberculosis (MTB) CD4 T cell recognition is still incomplete. Here we report that human Th1 cells specific for MTB are largely contained in a CXCR3(+)CCR6(+) memory subset and highly focused on three broadly immunodominant antigenic islands, all related to bacterial secretion systems. Our results refute the notion that secreted antigens act as a decoy, since both secreted proteins and proteins comprising the secretion system itself are targeted by a fully functional T cell response. In addition, several novel T cell antigens were identified which can be of potential diagnostic use, or as vaccine antigens. These results underline the power of a truly unbiased, genome-wide, analysis of CD4 MTB recognition based on the combined use of epitope predictions, high throughput ELISPOT, and T cell libraries using PBMCs from individuals latently infected with MTB.


Assuntos
Memória Imunológica , Tuberculose Latente/imunologia , Mycobacterium tuberculosis/imunologia , Receptores CCR6/metabolismo , Receptores CXCR3/metabolismo , Células Th1/imunologia , Adulto , Idoso , Genoma Bacteriano , Estudo de Associação Genômica Ampla , Interações Hospedeiro-Patógeno , Humanos , Tuberculose Latente/genética , Pessoa de Meia-Idade , Mycobacterium tuberculosis/genética , Receptores CCR6/genética , Receptores CXCR3/genética , Células Th1/metabolismo , Adulto Jovem
13.
Nature ; 484(7395): 514-8, 2012 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-22466287

RESUMO

IL-17-producing CD4+ T helper cells (TH17) have been extensively investigated in mouse models of autoimmunity. However, the requirements for differentiation and the properties of pathogen-induced human TH17 cells remain poorly defined. Using an approach that combines the in vitro priming of naive T cells with the ex vivo analysis of memory T cells, we describe here two types of human TH17 cells with distinct effector function and differentiation requirements. Candida albicans-specific TH17 cells produced IL-17 and IFN-γ, but no IL-10, whereas Staphylococcus aureus-specific TH17 cells produced IL-17 and could produce IL-10 upon restimulation. IL-6, IL-23 and IL-1ß contributed to TH17 differentiation induced by both pathogens, but IL-1ß was essential in C. albicans-induced TH17 differentiation to counteract the inhibitory activity of IL-12 and to prime IL-17/IFN-γ double-producing cells. In addition, IL-1ß inhibited IL-10 production in differentiating and in memory TH17 cells, whereas blockade of IL-1ß in vivo led to increased IL-10 production by memory TH17 cells. We also show that, after restimulation, TH17 cells transiently downregulated IL-17 production through a mechanism that involved IL-2-induced activation of STAT5 and decreased expression of ROR-γt. Taken together these findings demonstrate that by eliciting different cytokines C. albicans and S. aureus prime TH17 cells that produce either IFN-γ or IL-10, and identify IL-1ß and IL-2 as pro- and anti-inflammatory regulators of TH17 cells both at priming and in the effector phase.


Assuntos
Candida albicans/imunologia , Interferon gama/biossíntese , Interleucina-10/biossíntese , Interleucina-1beta/imunologia , Staphylococcus aureus/imunologia , Células Th17/imunologia , Células Th17/metabolismo , Apresentação do Antígeno/imunologia , Diferenciação Celular , Regulação para Baixo , Humanos , Memória Imunológica/imunologia , Interleucina-17/biossíntese , Interleucina-2/antagonistas & inibidores , Interleucina-2/imunologia , Ativação Linfocitária , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Fator de Transcrição STAT5/metabolismo , Células Th17/citologia , Fator de Necrose Tumoral alfa/metabolismo
14.
Immunol Rev ; 240(1): 40-51, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21349085

RESUMO

Studies on immunologic memory in animal models and especially in the human system are instrumental to identify mechanisms and correlates of protection necessary for vaccine development. In this article, we provide an overview of the cellular basis of immunologic memory. We also describe experimental approaches based on high throughput cell cultures, which we have developed to interrogate human memory T cells, B cells, and plasma cells. We discuss how these approaches can provide new tools and information for vaccine design, in a process that we define as 'analytic vaccinology'.


Assuntos
Linfócitos B/imunologia , Interações Hospedeiro-Patógeno , Memória Imunológica , Linfócitos T/imunologia , Desenho de Drogas , Humanos , Vacinas/imunologia
15.
Expert Opin Ther Targets ; 13(2): 141-52, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19236233

RESUMO

OBJECTIVE: Cell infection by HIV-1 is inhibited by both the expression of CD38 and a soluble peptide (sCD38p) corresponding to its extracellular membrane-proximal amino acid sequence (amino acids 51 - 74). We show here the effects of PEG conjugation to sCD38p and provide new insights into the mechanisms behind the anti-HIV-1 effects of CD38 and derived peptides. RESEARCH DESIGN/METHODS: In-vitro and in-silico study. RESULTS: PEGylation of sCD38p increased its ability to inhibit replication of HIV-1 in MT-4 cells and syncytia formation in cocultures of MT-2 and persistently HIV-1(IIIB)-infected H9(IIIB) cells. In silico modeling suggests that sCD38p and CD4 form stable heterodimers involving, among others, an interaction between lysine 57 (K57) of CD38 and a groove in the CD4 receptor, which, in CD4/gp120 complexes, is partially occupied by a lysine residue of the HIV-1 envelope glycoprotein. K57 substitution with a glycine in sCD38p impaired its ability to inhibit syncytia formation in MT-2/H9(IIIB) cell cocultures and gp120 binding to CD4 in a mouse T cell line expressing human but not mouse CD4. CONCLUSIONS: PEGylation significantly improves the anti-HIV-1 activity of sCD38p, whose effect is probably due to competition with gp120 for a common binding site on CD4 although other mechanisms cannot be excluded so far. The inhibitory concentrations of the sCD38p-PEG as well as its poor toxicity, merit further consideration in anti-HIV-1 strategies.


Assuntos
ADP-Ribosil Ciclase 1/farmacologia , Fármacos Anti-HIV/farmacologia , HIV-1/efeitos dos fármacos , Polietilenoglicóis/química , ADP-Ribosil Ciclase 1/química , Animais , Sítios de Ligação , Antígenos CD4/metabolismo , Linhagem Celular , Linhagem Celular Tumoral , Técnicas de Cocultura , Células Gigantes/efeitos dos fármacos , Células Gigantes/virologia , Proteína gp120 do Envelope de HIV/metabolismo , Infecções por HIV/tratamento farmacológico , HIV-1/metabolismo , Humanos , Camundongos , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo , Replicação Viral/efeitos dos fármacos
16.
Curr HIV Res ; 6(4): 306-17, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18691029

RESUMO

The feline AIDS model for HIV-1 treatment failed in the 1990s, due to structural features resembling protease inhibitor (PI) resistant HIV-1 variants. Widespread drug-resistance to PIs now invokes the possibility of rescuing feline immunodeficiency virus (FIV) as a model for PI treatment. We here analyzed susceptibility of FIV to second generation PIs, lopinavir, atazanavir, and the structurally unrelated non-peptidic PI tipranavir. We found that FIV protease resembles HIV-1 protease drug resistance mutations limiting binding of lopinavir and atazanavir but not tipranavir. All three PIs were found to inhibit FIV replication in a concentration-dependent manner, but only tipranavir inhibited FIV similarly to HIV-1. This drug inhibited FIV synergistically with ritonavir. Inhibition of protease activity was confirmed by Western blot analysis. In molecular docking simulations, tipranavir displayed energetically favorable interactions with the catalytic cavity of the mature dimeric FIV protease. The calculated hydrogen bond network was similar to that found in HIV-1 protease/tipranavir complexes and involved atoms in the protein backbone. We also modeled the interaction of tipranavir with an immature protease monomer, suggesting that inhibition of protease dimerization may be a secondary modality for FIV inhibition by tipranavir. In conclusion, tipranavir is the first FDA-approved non-reverse transcriptase inhibitor of HIV-1 to show anti-FIV properties. The tipranavir response by FIV may 1) support the idea of using FIV as a small animal model for PI-resistant HIV-1, thus expanding access to animal AIDS models; and 2) pave the way for development of novel broad-based inhibitors for treatment of drug resistant HIV-1.


Assuntos
Fármacos Anti-HIV/farmacologia , Modelos Animais de Doenças , Farmacorresistência Viral , Inibidores da Protease de HIV/farmacologia , HIV-1/efeitos dos fármacos , Vírus da Imunodeficiência Felina/efeitos dos fármacos , Piridinas/farmacologia , Pironas/farmacologia , Inibidores da Transcriptase Reversa/farmacologia , Sequência de Aminoácidos , Animais , Fármacos Anti-HIV/metabolismo , Gatos , Linhagem Celular , Farmacorresistência Viral/genética , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , Protease de HIV/química , Protease de HIV/efeitos dos fármacos , Protease de HIV/genética , Inibidores da Protease de HIV/metabolismo , HIV-1/enzimologia , Humanos , Vírus da Imunodeficiência Felina/enzimologia , Modelos Moleculares , Dados de Sequência Molecular , Mutação , Piridinas/metabolismo , Pironas/metabolismo , Inibidores da Transcriptase Reversa/metabolismo
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