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1.
Blood ; 125(19): 2937-47, 2015 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-25833958

RESUMO

CD4(+)CD25(+)FoxP3(+) regulatory T cells (Treg) are critical elements for maintaining immune tolerance, for instance to exogenous antigens that are introduced during therapeutic interventions such as cell/organ transplant or gene/protein replacement therapy. Coadministration of antigen with rapamycin simultaneously promotes deletion of conventional CD4(+) T cells and induction of Treg. Here, we report that the cytokine FMS-like receptor tyrosine kinase ligand (Flt3L) enhances the in vivo effect of rapamycin. This occurs via selective expansion of plasmacytoid dendritic cells (pDCs), which further augments the number of Treg. Whereas in conventional DCs, rapamycin effectively blocks mammalian target of rapamycin (mTOR) 1 signaling induced by Flt3L, increased mTOR1 activity renders pDCs more resistant to inhibition by rapamycin. Consequently, Flt3L and rapamycin synergistically promote induction of antigen-specific Treg via selective expansion of pDCs. This concept is supported by the finding that Treg induction is abrogated upon pDC depletion. The combination with pDCs and rapamycin is requisite for Flt3L/antigen-induced Treg induction because Flt3L/antigen by itself fails to induce Treg. As co-administering Flt3L, rapamycin, and antigen blocked CD8(+) T-cell and antibody responses in models of gene and protein therapy, we conclude that the differential effect of rapamycin on DC subsets can be exploited for improved tolerance induction.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Células Dendríticas/imunologia , Fatores de Transcrição Forkhead/metabolismo , Subunidade alfa de Receptor de Interleucina-2/metabolismo , Proteínas de Membrana/metabolismo , Sirolimo/farmacologia , Linfócitos T Reguladores/imunologia , Animais , Antibióticos Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Western Blotting , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/metabolismo , Células Cultivadas , Citocinas , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/metabolismo , Sinergismo Farmacológico , Citometria de Fluxo , Humanos , Tolerância Imunológica/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fosforilação , Transdução de Sinais , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/metabolismo , Serina-Treonina Quinases TOR/metabolismo
2.
Egypt Heart J ; 76(1): 48, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38625596

RESUMO

BACKGROUND: This systematic review and meta-analysis aimed to compare the efficacy and safety of cangrelor as compared to ticagrelor in patients with ST-elevated myocardial infarction (STEMI) who underwent percutaneous intervention. METHODS: PubMed, Embase, Scopus, Web of Science, Cochrane CENTRAL, and ClinicalTrials.gov databases were searched for relevant head-on-comparison or swapping studies. The primary outcome was the rate of high platelet reactivity (HPR) at specific time intervals after stopping cangrelor infusion during the first 24 h. Secondary outcomes were the risks of thrombosis, all-cause mortality and bleeding. Pooled odds ratios (ORs) were calculated using random-effects models. RESULTS: A total of 1018 studies were screened and eight were included in the analysis. There were four head-on-comparison studies and four swapping studies. There was no significant difference in the proportion of patients achieving a high platelet reactivity in swapping studies [OR, 0.71 (95% CI 0.04, 13.87), p = 0.82, i2 = 88%]. In head-on-comparison studies, PRU from Fig. 2B shows there was no significant reduction in high platelet reactivity [mean difference - 77.83 (95% CI - 238.84, 83.18), p < 0.001, i2 = 100%]. PRU results from (Fig. 2C) show a mean difference of 7.38 (95% CI - 29.74, 44.51), p < 0.001, i2 = 97%. There was no significant difference in the risks of thrombosis [OR, 0.91 (95% CI 0.20, 4.13), p = 0.81, i2 = 0%], all-cause mortality [OR, 3.52 (95% CI 0.44, 27.91), p = 0.24, i2 = 26%] and bleeding [OR, 0.89 (95% CI 0.37, 2.17), p = 0.93, i2 = 0%] between the two groups as revealed in the head-on-comparison studies. CONCLUSION: The efficacy and safety profiles of cangrelor and ticagrelor were similar in patients with STEMI.

3.
Int J Cancer ; 130(2): 328-37, 2012 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-21365650

RESUMO

Cancer stem cells (CSCs) are initiating cells in colorectal cancer (CRC). Colorectal tumours undergo epithelial to mesenchymal transition (EMT)-like processes at the invasive front, enabling invasion and metastasis, and recent studies have linked this process to the acquisition of stem cell-like properties. It is of fundamental importance to understand the molecular events leading to the establishment of cancer initiating cells and how these mechanisms relate to cellular transitions during tumourigenesis. We use an in vitro system to recapitulate changes in CRC cells at the invasive front (mesenchymal-like cells) and central mass (epithelial-like cells) of tumours. We show that the mesoderm inducer BRACHYURY is expressed in a subpopulation of CRC cells that resemble invasive front mesenchymal-like cells, where it acts to impose characteristics of CSCs in a fully reversible manner, suggesting reversible formation and modulation of such cells. BRACHYURY, itself regulated by the oncogene ß-catenin, influences NANOG and other 'stemness' markers including a panel of markers defining CRC-CSC whose presence has been linked to poor patient prognosis. Similar regulation of NANOG through BRACHYURY was observed in other cells lines, suggesting this might be a pathway common to cancer cells undergoing mesenchymal transition. We suggest that BRACHYURY may regulate NANOG in mesenchymal-like CRC cells to impose a 'plastic-state', allowing competence of cells to respond to signals prompting invasion or metastasis.


Assuntos
Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Proteínas Fetais/genética , Células-Tronco Neoplásicas/fisiologia , Proteínas com Domínio T/genética , Antígeno AC133 , Antígenos CD/biossíntese , Antígenos CD/genética , Carcinoma Embrionário/genética , Carcinoma Embrionário/metabolismo , Carcinoma Embrionário/patologia , Moléculas de Adesão Celular Neuronais/biossíntese , Moléculas de Adesão Celular Neuronais/genética , Contagem de Células , Processos de Crescimento Celular/genética , Linhagem Celular Tumoral , Neoplasias Colorretais/metabolismo , Transição Epitelial-Mesenquimal , Proteínas Fetais/biossíntese , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Glicoproteínas/biossíntese , Glicoproteínas/genética , Proteínas de Homeodomínio/biossíntese , Proteínas de Homeodomínio/genética , Humanos , Receptores de Hialuronatos/biossíntese , Receptores de Hialuronatos/genética , Proteína Homeobox Nanog , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Peptídeos/genética , Proteínas com Domínio T/biossíntese , beta Catenina/biossíntese , beta Catenina/genética
4.
Cureus ; 14(10): e30201, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36381755

RESUMO

Diabetes mellitus (DM) is a chronic metabolic disease characterized by inappropriately elevated blood glucose levels. If not treated at the early stage, it can lead to complications like diabetic retinopathy (DR) and diabetic nephropathy (DN) which are often associated with severe morbidity and mortality. This study was designed to identify the prevalence of retinopathy and nephropathy in diabetic patients and also to determine the correlation between DR and DN. In this cross-sectional study, a total of 84 diabetic patients (Male: Female- 53:31) were included. The mean age at presentation was 54.06 ± 9.85 years. Among them, 28% of patients had a duration of diabetes of < 5 years. Nearly 42% and 30% of patients had diabetes between 5-10 years, and more than 10 years respectively. At the time of presentation to us, a total of 42.8% of patients had a combination of nephropathy and retinopathy, 40.4% of patients had only retinopathy, and 16.6% of patients with only nephropathy. Among patients with nephropathy and microalbuminuria, only 5.9% had DR ranging from mild to a moderate degree and none had severe DR. In patients with macroalbuminuria, 26.2% had moderate to severe DR. Microvascular complications are more prevalent in diabetics with disease progression. Microalbuminuria is a marker for retinopathy and these patients require ophthalmic evaluation at the earliest. Early recognition and management of these, can reduce the occurrence of complications as well as disease progression, thus reducing the related mortality.

5.
N Am J Med Sci ; 6(1): 50-7, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24678479

RESUMO

BACKGROUND: The increase in invasive fungal infections (IFIs) in neonatal intensive care unit (NICU) is jeopardizing the survival of preterm neonates. Probiotics modulating the intestinal microflora of preterm neonates may minimize enteral fungal colonization. AIMS: This study was to examine whether probiotic supplementation in neonates reduced fungal septicemia. MATERIALS AND METHODS: This prospective, randomized, double blind trial investigating the supplementation of preterm infants with a probiotic was done from May 2012 to April 2013, with 112 subjects randomized into two groups. PRIMARY OUTCOME: Decreased fungal colonization in gastrointestinal tract. Others: Incidence of late onset septicemia; duration of the primary hospital admission; number of days until full enteral feeds established. RESULTS: Full feed establishment was earlier in probiotics group compared to placebo group (P = 0.016). The duration of hospitalization was less in the probiotic group (P = 0.002). Stool fungal colonization, an important outcome parameter was 3.03 ± 2.33 × 10(5) colony formation units (CFU) in the probiotics group compared to 3 ± 1.5 × 10(5) CFU in the placebo group (P = 0.03). Fungal infection is less in the study group (P = 0.001). CONCLUSION: The key features of our study were reduced enteral fungal colonization, reduce invasive fungal sepsis, earlier establishment of full enteral feeds, and reduced duration of hospital stay in the probiotics group.

6.
Artigo em Inglês | MEDLINE | ID: mdl-25364772

RESUMO

Adoptive cell therapy utilizing ex vivo expanded polyclonal CD4+CD25+FOXP3+ regulatory T cells (Treg) is in use in clinical trials for the treatment of type 1 diabetes and prevention of graft vs host disease in bone marrow transplantation. Here we seek to evaluate this approach in the treatment of inherited protein deficiencies, i.e. hemophilia, which is often complicated by antibody formation against the therapeutic protein. Treg from mice that express GFP-marked FoxP3 were highly purified by two-step magnetic/flow sorting and ex vivo expanded 50- to 80-fold over a 2-week culture period upon stimulation with antibody-coated microbeads. FoxP3 expression was maintained in >80% of expanded Treg, which also expressed high levels of CD62L and CTLA-4. Transplanted Treg suppressed inhibitory antibody formation against coagulation factors VIII and IX in protein and gene therapies in strain-matched hemophilia A and B mice, including in mice with pre-existing antibodies. Although transplanted Treg became undetectable within two weeks, suppression persisted for >2 months. Additional studies suggested that antigen-specific suppression emerged due to induction of endogenous Treg. The outcomes of these studies support the concept that cell therapy with ex vivo expanded autologous Treg can be used successfully to minimize immune responses in gene and protein replacement therapies.

7.
N Am J Med Sci ; 5(8): 480-5, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24083224

RESUMO

BACKGROUND: The spectrum of liver dysfunction in children with dengue infection is wide and has been associated with disease severity. AIMS: This study was undertaken to estimate the range of hepatic involvement in dengue infection in children. MATERIALS AND METHODS: This study assessed the biochemical and clinical profile of hepatic involvement by dengue virus in 120 children with serologically positive dengue fever (DF), aged 2 months to 14 years. RESULTS: All cases were grouped into DF without warning signs (Group 1), DF with warning signs (Group 2) and severe dengue (Group 3) according to revised World Health Organization 2009 criteria. The spectrum of hepatic manifestations included hepatomegaly (80.8%), hepatic tenderness (46.3%), jaundice (60%), raised aspartate transaminase (AST), alanine transaminase (ALT) and prolonged prothrombin time (41.7%) and reduced serum albumin (56%). CONCLUSIONS: Hepatic dysfunction was observed more in Groups 2 and 3. There was 84.4% and 93.75% ALT and AST elevation respectively in Group 2 and 94.5% and 95.9% ALT and AST elevation respectively in Group 3 and fulminant hepatic failure was observed in Group 3. Therefore in a child with fever, jaundice, hepatomegaly and altered liver function tests, the diagnosis of dengue infection should be strongly considered in areas where dengue infection is endemic.

8.
Case Rep Vasc Med ; 2013: 386961, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24369523

RESUMO

Internal jugular phlebectasia presents as a soft cystic mass in the neck that appears on straining. We present a case of a 7-year-old girl who presented with a painless soft cystic mass in the neck associated with hoarseness of voice. Based on clinical examination and CT image, diagnosis of right internal jugular phlebectasia was made.

9.
Front Microbiol ; 2: 244, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22279442

RESUMO

Intramuscular (IM) administration of an adeno-associated viral (AAV) vector represents a simple and safe method of gene transfer for treatment of the X-linked bleeding disorder hemophilia B (factor IX, F.IX, deficiency). However, the approach is hampered by an increased risk of immune responses against F.IX. Previously, we demonstrated that the drug cocktail of immune suppressants rapamycin, IL-10, and a specific peptide (encoding a dominant CD4(+) T cell epitope) caused an induction of regulatory T cells (Treg) with a concomitant apoptosis of antigen-specific effector T cells (Nayak et al., 2009). This protocol was effective in preventing inhibitory antibody formation against human F.IX (hF.IX) in muscle gene transfer to C3H/HeJ hemophilia B mice (with targeted F9 gene deletion). Here, we show that this protocol can also be used to reverse inhibitor formation. IM injection of AAV1-hF.IX vector resulted in inhibitors of on average 8-10 BU within 1 month. Subsequent treatment with the tolerogenic cocktail accomplished a rapid reduction of hF.IX-specific antibodies to <2 BU, which lasted for >4.5 months. Systemic hF.IX expression increased from undetectable to >200 ng/ml, and coagulation times improved. In addition, we developed an alternative prophylactic protocol against inhibitor formation that did not require knowledge of T cell epitopes, consisting of daily oral administration of rapamycin for 1-month combined with frequent, low-dose intravenous injection of hF.IX protein. Experiments in T cell receptor transgenic mice showed that the route and dosing schedule of drug administration substantially affected Treg induction. When combined with intravenous antigen administration, oral delivery of rapamycin had to be performed daily in order to induce Treg, which were suppressive and phenotypically comparable to natural Treg.

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