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1.
Proc Natl Acad Sci U S A ; 116(3): 970-975, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30591564

RESUMO

Receptor-interacting serine/threonine-protein kinase 1 (RIPK1) is a critical regulator of cell death and inflammation, but its relevance for human disease pathogenesis remains elusive. Studies of monogenic disorders might provide critical insights into disease mechanisms and therapeutic targeting of RIPK1 for common diseases. Here, we report on eight patients from six unrelated pedigrees with biallelic loss-of-function mutations in RIPK1 presenting with primary immunodeficiency and/or intestinal inflammation. Mutations in RIPK1 were associated with reduced NF-κB activity, defective differentiation of T and B cells, increased inflammasome activity, and impaired response to TNFR1-mediated cell death in intestinal epithelial cells. The characterization of RIPK1-deficient patients highlights the essential role of RIPK1 in controlling human immune and intestinal homeostasis, and might have critical implications for therapies targeting RIPK1.


Assuntos
Diferenciação Celular , Imunidade nas Mucosas/genética , Doenças Inflamatórias Intestinais , Mucosa Intestinal , Proteína Serina-Treonina Quinases de Interação com Receptores , Imunodeficiência Combinada Severa , Linfócitos B/imunologia , Linfócitos B/patologia , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Células Epiteliais/imunologia , Células Epiteliais/patologia , Feminino , Células HCT116 , Células HEK293 , Humanos , Doenças Inflamatórias Intestinais/genética , Doenças Inflamatórias Intestinais/imunologia , Doenças Inflamatórias Intestinais/patologia , Mucosa Intestinal/imunologia , Mucosa Intestinal/patologia , Masculino , Mutação , NF-kappa B/genética , NF-kappa B/imunologia , Proteína Serina-Treonina Quinases de Interação com Receptores/deficiência , Proteína Serina-Treonina Quinases de Interação com Receptores/imunologia , Imunodeficiência Combinada Severa/genética , Imunodeficiência Combinada Severa/imunologia , Imunodeficiência Combinada Severa/patologia , Linfócitos T/imunologia , Linfócitos T/patologia
2.
Cell Discov ; 4: 61, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30455981

RESUMO

A loss-of-function mutation in tetratricopeptide repeat domain 7A (TTC7A) is a recently identified cause of human intestinal and immune disorders. However, clues to related underlying molecular dysfunctions remain elusive. It is now shown based on the study of TTC7A-deficient and wild-type cells that TTC7A is an essential nuclear protein. It binds to chromatin, preferentially at actively transcribed regions. Its depletion results in broad range of epigenomic changes at proximal and distal transcriptional regulatory elements and in altered control of the transcriptional program. Loss of WT_TTC7A induces general decrease in chromatin compaction, unbalanced cellular distribution of histones, higher nucleosome accessibility to nuclease digestion along with genome instability, and reduced cell viability. Our observations characterize for the first time unreported functions for TTC7A in the nucleus that exert a critical role in chromatin organization and gene regulation to safeguard healthy immune and intestinal status.

3.
Clin Immunol ; 161(2): 103-9, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26187144

RESUMO

Autosomal recessive human ZAP70 deficiency is a rare cause of combined immunodeficiency (CID) characterized by defective CD4 T cells and profound CD8 T cell lymphopenia. Herein, we report two novel patients that extend the molecular genetics, the clinical and functional phenotypes associated with the ZAP70 deficiency. The patients presented as infant-onset CID with severe infections caused by varicella zoster virus and live vaccines. Retrospective TCR excision circle newborn screening was normal in both patients. One patient carried a novel non-sense mutation (p.A495fsX75); the other a previously described misense mutation (p.A507V). In contrast to CD4 T cells, the majority of the few CD8 T cells showed expression of the ZAP70-related tyrosine kinase SYK that correlated with residual TCR signaling including calcium flux and degranulation. Our findings highlight the differential requirements of ZAP70 and SYK during thymic development, peripheral homeostasis as well as effector functions of CD4 and CD8 T cells.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Peptídeos e Proteínas de Sinalização Intracelular/imunologia , Proteínas Tirosina Quinases/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Imunodeficiência Combinada Severa/imunologia , Proteína-Tirosina Quinase ZAP-70/deficiência , Linfócitos T CD4-Positivos/imunologia , Pré-Escolar , Humanos , Síndromes de Imunodeficiência/imunologia , Lactente , Masculino , Mutação/imunologia , Estudos Retrospectivos , Transdução de Sinais/imunologia , Quinase Syk , Proteína-Tirosina Quinase ZAP-70/imunologia
4.
J Clin Invest ; 124(1): 328-37, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24292712

RESUMO

Multiple intestinal atresia (MIA) is a rare cause of bowel obstruction that is sometimes associated with a combined immunodeficiency (CID), leading to increased susceptibility to infections. The factors underlying this rare disease are poorly understood. We characterized the immunological and intestinal features of 6 unrelated MIA-CID patients. All patients displayed a profound, generalized lymphocytopenia, with few lymphocytes present in the lymph nodes. The thymus was hypoplastic and exhibited an abnormal distribution of epithelial cells. Patients also had profound disruption of the epithelial barrier along the entire gastrointestinal tract. Using linkage analysis and whole-exome sequencing, we identified 10 mutations in tetratricopeptide repeat domain­7A (TTC7A), all of which potentially abrogate TTC7A expression. Intestinal organoid cultures from patient biopsies displayed an inversion of apicobasal polarity of the epithelial cells that was normalized by pharmacological inhibition of Rho kinase. Our data indicate that TTC7A deficiency results in increased Rho kinase activity, which disrupts polarity, growth, and differentiation of intestinal epithelial cells, and which impairs immune cell homeostasis, thereby promoting MIA-CID development.


Assuntos
Atresia Intestinal/genética , Mucosa Intestinal/patologia , Proteínas/genética , Imunodeficiência Combinada Severa/genética , Sequência de Bases , Polaridade Celular , Células Cultivadas , Criança , Consanguinidade , Análise Mutacional de DNA , Células Epiteliais/fisiologia , Exoma , Feminino , Estudos de Associação Genética , Ligação Genética , Humanos , Lactente , Atresia Intestinal/imunologia , Atresia Intestinal/mortalidade , Atresia Intestinal/patologia , Linfonodos/patologia , Linfopenia/genética , Linfopenia/imunologia , Linfopenia/patologia , Masculino , Linhagem , Proteínas/metabolismo , Imunodeficiência Combinada Severa/imunologia , Imunodeficiência Combinada Severa/mortalidade , Imunodeficiência Combinada Severa/patologia , Timo/anormalidades , Timo/patologia , Quinases Associadas a rho/metabolismo
5.
Antimicrob Agents Chemother ; 56(5): 2750-2, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22314533

RESUMO

Screening for in vitro susceptibility to pyrimethamine and sequencing of the pfmdr2 and pfdhfr genes were performed in 140 Plasmodium falciparum isolates. The risk of in vitro resistance to pyrimethamine was analyzed with a logistic regression model. The mutation F423Y in pfmdr2 (odds ratio [OR] = 2.12 [confidence interval {CI}, 1.02 to 4.59]; P = 0.0489) and the mutation N51I, C59R, or S108N in pfdhfr (OR = 42.34 [CI, 5.52 to 324.61]; P = 0.0003) were independently associated with in vitro resistance to pyrimethamine.


Assuntos
Resistência a Medicamentos/genética , Antagonistas do Ácido Fólico/farmacologia , Genes de Protozoários , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Plasmodium falciparum/genética , Pirimetamina/farmacologia , Tetra-Hidrofolato Desidrogenase/genética , Antimaláricos/farmacologia , Humanos , Modelos Logísticos , Malária Falciparum/parasitologia , Análise Multivariada , Mutação , Plasmodium falciparum/isolamento & purificação , Reação em Cadeia da Polimerase , Análise de Sequência de DNA
6.
J Antimicrob Chemother ; 65(7): 1387-94, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20501488

RESUMO

OBJECTIVES: The aim of the study was to assess the in vitro potentiating effects of atorvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, in combination with mefloquine, chloroquine or monodesethylamodiaquine against Plasmodium falciparum and to evaluate whether the effects of atorvastatin could be associated with mutations or gene copy number in multidrug resistance (MDR)-like protein genes. METHODS: The susceptibilities of 21 parasite strains to combinations of atorvastatin with mefloquine, chloroquine or monodesethylamodiaquine were assessed using the in vitro isotopic microtest. Genotypes and gene copy number were assessed for pfmdr1, pfmdr2 and pfmrp genes. RESULTS: Atorvastatin demonstrated synergistic effects in combination with mefloquine. The mefloquine IC(50) (50% inhibitory concentration) was reduced by 7%, 24% and 37% in the presence of atorvastatin at concentrations of 0.1, 0.5 and 1.0 microM, respectively. The synergistic effect of atorvastatin on the response to mefloquine was significantly associated with pfmdr1 copy number. The concentration of atorvastatin that could reduce the IC(50) of mefloquine by 50% was 2.4 +/- 1.3 microM for the 12 strains that contained one copy of pfmdr1 and 5.8 +/- 2.1 microM for the 9 strains that contained two copies or more. The synergistic effect of atorvastatin in combination with mefloquine was found to be significantly unrelated to mutations in pfmdr1, pfmdr2 or pfmrp genes. CONCLUSIONS: The synergy of the effect of mefloquine at concentrations relevant to its achievable plasma concentrations in patients taking 80 mg of atorvastatin daily suggests that atorvastatin will be a good candidate in combination with mefloquine for malaria treatment.


Assuntos
Amodiaquina/análogos & derivados , Antimaláricos/farmacologia , Cloroquina/farmacologia , Ácidos Heptanoicos/farmacologia , Mefloquina/farmacologia , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Plasmodium falciparum/efeitos dos fármacos , Pirróis/farmacologia , Amodiaquina/farmacologia , Atorvastatina , DNA de Protozoário/genética , Sinergismo Farmacológico , Dosagem de Genes , Genótipo , Humanos , Concentração Inibidora 50 , Testes de Sensibilidade Parasitária , Plasmodium falciparum/genética
7.
Malar J ; 9: 139, 2010 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-20497586

RESUMO

BACKGROUND: Quinine (QN) remains the first line anti-malarial drug for the treatment of complicated malaria in Europe and Africa. The emergence of QN resistance has been documented. QN resistance is not yet a significant problem, but there is an urgent need to discover partners for use in combination with QN. The aim of the study was to assess the in vitro potentiating effects of atorvastatin (AVA), a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, in combination with QN against Plasmodium falciparum and to evaluate whether the effects of AVA could be associated with gene copy number or mutations in genes involved in QN resistance, such as pfcrt, pfmdr1, pfmrp and pfnhe. METHODS: The susceptibilities to combination of AVA with QN were assessed against 21 parasite strains using the in vitro isotopic microtest. Genotypes and gene copy number were assessed for pfcrt, pfmdr1, pfmdr2, pfmrp genes. In addition, the number of DNNND, DDNHNDNHNN repeats in pfnhe-1 ms4760 and the ms4760 profile were determined for each strains of P. falciparum. RESULTS: AVA demonstrated synergistic effects in combination with QN against 21 P. falciparum strains. The QN IC50 was reduced by 5% (0% to 15%; 95%CI: 1%-8%), 10% (3% to 23%; 95%CI: 7%-14%) and 22% (14% to 40%; 95%CI: 19%-25%) in presence of AVA at concentrations of 0.1, 0.5 and 1.0 microM, respectively. These reductions were all significant (p < 0.009). The reduction in the QN IC50 in presence of AVA was not significantly correlated with the QN IC50 (r = 0.22, P = 0.3288) or the AVA IC50 (r = 0.03, P = 0.8946). The synergistic effect of AVA in combination with QN was not significantly associated with polymorphisms in the pfcrt, pfmdr1, pfmrp, and pfnhe-1 genes that could be involved in QN resistance. The synergistic effect of AVA on QN responses was not significantly associated with pfmdr1 copy number (P = 0.0428). CONCLUSION: The synergistic effect of AVA in combination with QN was found to be unrelated to mutations occurring in transport protein genes involved in QN drug resistance. The different mechanisms of drug uptake and/or mode of action for AVA compared to the other anti-malarial drugs, as well as the AVA-mediated synergy of the anti-malarial effect of QN, suggests that AVA will be a good candidate for combinatorial malaria treatment. All of these observations support calls for both an in vivo evaluation with pharmacokinetic component and clinical trials of AVA as an anti-malarial therapy.


Assuntos
Antimaláricos/farmacologia , Ácidos Heptanoicos/farmacologia , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Mutação , Plasmodium falciparum/efeitos dos fármacos , Pirróis/farmacologia , Quinina/farmacologia , Transportadores de Cassetes de Ligação de ATP/genética , Antimaláricos/uso terapêutico , Atorvastatina , Resistência a Medicamentos , Sinergismo Farmacológico , Dosagem de Genes/efeitos dos fármacos , Variação Genética , Genótipo , Concentração Inibidora 50 , Malária Falciparum/tratamento farmacológico , Malária Falciparum/genética , Proteínas de Membrana Transportadoras/genética , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Testes de Sensibilidade Parasitária , Plasmodium falciparum/genética , Plasmodium falciparum/isolamento & purificação , Proteínas de Protozoários/genética , Quinina/uso terapêutico
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