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1.
J Immunol ; 212(12): 1904-1912, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38668728

RESUMO

NK cells have been shown to exhibit inflammatory and immunoregulatory functions in a variety of healthy and diseased settings. In the context of chronic viral infection and cancer, distinct NK cell populations that inhibit adaptive immune responses have been observed. To understand how these cells arise and further characterize their immunosuppressive role, we examined in vitro conditions that could polarize human NK cells into an inhibitory subset. TGF-ß1 has been shown to induce regulatory T cells in vitro and in vivo; we therefore investigated if TGF-ß1 could also induce immunosuppressive NK-like cells. First, we found that TGF-ß1/IL-15, but not IL-15 alone, induced CD103+CD49a+ NK-like cells from peripheral blood NK cells, which expressed markers previously associated with inhibitory CD56+ innate lymphoid cells, including high expression of GITR and CD101. Moreover, supernatant from ascites collected from patients with ovarian carcinoma also induced CD103+CD49a+ NK-like cells in vitro in a TGF-ß-dependent manner. Interestingly, TGF-ß1/IL-15-induced CD103+CD56+ NK-like cells suppressed autologous CD4+ T cells in vitro by reducing absolute number, proliferation, and expression of activation marker CD25. Collectively, these findings provide new insight into how NK cells may acquire an inhibitory phenotype in TGF-ß1-rich environments.


Assuntos
Interleucina-15 , Células Matadoras Naturais , Fator de Crescimento Transformador beta1 , Humanos , Células Matadoras Naturais/imunologia , Interleucina-15/imunologia , Interleucina-15/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Feminino , Antígenos CD/metabolismo , Antígenos CD/imunologia , Neoplasias Ovarianas/imunologia , Neoplasias Ovarianas/patologia , Cadeias alfa de Integrinas/metabolismo , Cadeias alfa de Integrinas/imunologia , Antígeno CD56/metabolismo , Células Cultivadas , Subpopulações de Linfócitos/imunologia , Subpopulações de Linfócitos/metabolismo , Ativação Linfocitária/imunologia
2.
Proc Natl Acad Sci U S A ; 120(12): e2214512120, 2023 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-36913566

RESUMO

Biocatalytic C-H activation has the potential to merge enzymatic and synthetic strategies for bond formation. FeII/αKG-dependent halogenases are particularly distinguished for their ability both to control selective C-H activation as well as to direct group transfer of a bound anion along a reaction axis separate from oxygen rebound, enabling the development of new transformations. In this context, we elucidate the basis for the selectivity of enzymes that perform selective halogenation to yield 4-Cl-lysine (BesD), 5-Cl-lysine (HalB), and 4-Cl-ornithine (HalD), allowing us to probe how site-selectivity and chain length selectivity are achieved. We now report the crystal structure of the HalB and HalD, revealing the key role of the substrate-binding lid in positioning the substrate for C4 vs C5 chlorination and recognition of lysine vs ornithine. Targeted engineering of the substrate-binding lid further demonstrates that these selectivities can be altered or switched, showcasing the potential to develop halogenases for biocatalytic applications.


Assuntos
Aminoácidos , Lisina , Halogenação , Ornitina
3.
Nat Chem Biol ; 18(2): 171-179, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34937913

RESUMO

FeII/α-ketoglutarate (FeII/αKG)-dependent enzymes offer a promising biocatalytic platform for halogenation chemistry owing to their ability to functionalize unactivated C-H bonds. However, relatively few radical halogenases have been identified to date, limiting their synthetic utility. Here, we report a strategy to expand the palette of enzymatic halogenation by engineering a reaction pathway rather than substrate selectivity. This approach could allow us to tap the broader class of FeII/αKG-dependent hydroxylases as catalysts by their conversion to halogenases. Toward this goal, we discovered active halogenases from a DNA shuffle library generated from a halogenase-hydroxylase pair using a high-throughput in vivo fluorescent screen coupled to an alkyne-producing biosynthetic pathway. Insights from sequencing halogenation-active variants along with the crystal structure of the hydroxylase enabled engineering of a hydroxylase to perform halogenation with comparable activity and higher selectivity than the wild-type halogenase, showcasing the potential of harnessing hydroxylases for biocatalytic halogenation.


Assuntos
Halogênios/metabolismo , Oxigenases de Função Mista/química , Oxigenases de Função Mista/metabolismo , Domínio Catalítico , Halogenação , Modelos Moleculares , Conformação Proteica , Engenharia de Proteínas , Especificidade por Substrato
4.
Cancer Immunol Immunother ; 72(7): 2375-2392, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36943460

RESUMO

Immunotherapeutic strategies aimed at enhancing tumor cell killing by tumor-specific T cells hold great potential for reducing tumor burden and prolonging survival of cancer patients. Although many potential tumor antigens have been described, identifying relevant targets when designing anti-cancer vaccines or targeted cell therapies remains a challenge. To identify novel, potentially immunogenic candidate tumor antigens, we performed integrated tumor transcriptomic, seromic, and proteomic analyses of high grade serous ovarian cancer (HGSC) patient tumor samples. We identified tumor neo-antigens and over-expressed antigens using whole exome and RNA sequencing and examined these in relation to patient-matched auto-antibody repertoires. Focusing on MHC class I epitopes recognized by CD8+ T cells, HLA-binding epitopes were identified or predicted from the highly expressed, mutated, or auto-antibody target antigen, or MHC-associated peptides (MAPs). Recognition of candidate antigenic peptides was assessed within the tumor-infiltrating T lymphocyte (TIL) population expanded from each patient. Known tumor-associated antigens (TAA) and cancer/testis antigens (CTA) were commonly found in the auto-antibody and MAP repertoires and CD8+ TILs recognizing epitopes from these antigens were detected, although neither expression level nor the presence of auto-antibodies correlated with TIL recognition. Auto-antibodies against tumor-mutated antigens were found in most patients, however, no TIL recognition of the highest predicted affinity neo-epitopes was detected. Using high expression level, auto-antibody recognition, and epitope prediction algorithms, we identified epitopes in 5 novel antigens (MOB1A, SOCS3, TUBB, PRKAR1A, CCDC6) recognized by HGSC patient TILs. Furthermore, selection of epitopes from the MAP repertoire identified 5 additional targets commonly recognized by multiple patient TILs. We find that the repertoire of TIL specificities includes recognition of highly expressed and immunogenic self-antigens that are processed and presented by tumors. These results indicate an ongoing autoimmune response against a range of self-antigens targeted by HGSC TILs.


Assuntos
Linfócitos do Interstício Tumoral , Neoplasias Ovarianas , Masculino , Humanos , Feminino , Epitopos/metabolismo , Linfócitos T CD8-Positivos , Proteômica , Multiômica , Antígenos de Neoplasias , Peptídeos , Autoantígenos , Epitopos de Linfócito T
6.
Int J Mol Sci ; 24(17)2023 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-37686192

RESUMO

Globally, over 3.5 billion people are infected with intestinal parasites each year, resulting in over 200,000 deaths. Three of the most common protozoan pathogens that affect the gastrointestinal tract of humans are Cryptosporidium spp., Giardia intestinalis, and Entamoeba histolytica. Other protozoan agents that have been implicated in gastroenteritis in humans include Cyclospora cayetanensis, Dientamoeba fragilis, Blastocystis hominis, and the microsporidia Enterocytozoon bieneusi and Encephalitozoon intestinalis. Genetic Signatures previously developed a 3base™ multiplexed Real-Time PCR (mRT-PCR) enteric protozoan kit (EP001) for the detection of Giardia intestinalis/lamblia/duodenalis, Cryptosporidium spp., E. histolytica, D. fragilis, and B. hominis. We now describe improvements to this kit to produce a more comprehensive assay, including C. cayetanensis, E. bieneusi, and E. intestinalis, termed EP005. The clinical performance of EP005 was assessed using a set of 380 clinical samples against a commercially available PCR test and other in-house nucleic acid amplification tests where commercial tests were not available. All methods provided at least 90% agreement. EP005 had no cross-reactivity against 82 organisms commonly found in the gut. The EP005 method streamlines the detection of gastrointestinal parasites and addresses the many challenges of traditional microscopic detection, resulting in cost savings and significant improvements in patient care.


Assuntos
Doenças Transmissíveis , Criptosporidiose , Cryptosporidium , Gastroenteropatias , Giardia lamblia , Infecções por Protozoários , Humanos , Infecções por Protozoários/diagnóstico , Giardia lamblia/genética
7.
J Immunol ; 195(10): 4632-40, 2015 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-26447227

RESUMO

TLR-induced maturation of dendritic cells (DCs) leads to the production of proinflammatory cytokines as well as the upregulation of various molecules involved in T cell activation. These are believed to be the critical events that account for the induction of the adaptive immune response. In this study, we have examined the role of miR-155 in DC function and the induction of immunity. Using a model in which the transfer of self-Ag-pulsed, TLR-matured DCs can induce a functional CD8 T cell response and autoimmunity, we find that DCs lacking miR-155 have an impaired ability to break immune tolerance. Importantly, transfer of self- Ag-pulsed DCs overexpressing miR-155 was sufficient to break tolerance in the absence of TLR stimuli. Although these unstimulated DCs induced T cell function in vivo, there was no evidence for the upregulation of costimulatory ligands or cytokine secretion. Further analysis showed that miR-155 influenced the level of the phosphatase SHIP1 in DCs and that the lack of SHIP1 in DCs was sufficient to break T cell tolerance in vivo, again in the absence of TLR-induced DC maturation. Our study demonstrates that the overexpression of miR-155 in DCs is a critical event that is alone sufficient to break self-tolerance and promote a CD8-mediated autoimmune response in vivo. This process is independent of the induction of conventional DC maturation markers, indicating that miR-155 regulation of SHIP represents a unique axis that regulates DC function in vivo.


Assuntos
Células Dendríticas/metabolismo , Tolerância Imunológica/imunologia , MicroRNAs/biossíntese , Monoéster Fosfórico Hidrolases/metabolismo , Animais , Autoimunidade/genética , Autoimunidade/imunologia , Linfócitos T CD8-Positivos/imunologia , Diferenciação Celular/imunologia , Células Cultivadas , Células Dendríticas/citologia , Tolerância Imunológica/genética , Inositol Polifosfato 5-Fosfatases , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , MicroRNAs/genética , Fosfatidilinositol-3,4,5-Trifosfato 5-Fosfatases , Monoéster Fosfórico Hidrolases/genética , Regulação para Cima
8.
Microorganisms ; 11(5)2023 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-37317133

RESUMO

Arboviruses are a diverse family of vector-borne pathogens that include members of the Flaviviridae, Togaviridae, Phenuviridae, Peribunyaviridae, Reoviridae, Asfarviridae, Rhabdoviridae, Orthomyxoviridae and Poxviridae families. It is thought that new world arboviruses such as yellow fever virus emerged in the 16th century due to the slave trade from Africa to America. Severe disease-causing viruses in humans include Japanese encephalitis virus (JEV), yellow fever virus (YFV), dengue virus (DENV), West Nile virus (WNV), Zika virus (ZIKV), Crimean-Congo hemorrhagic fever virus (CCHFV), severe fever with thrombocytopenia syndrome virus (SFTSV) and Rift Valley fever virus (RVFV). Numerous methods have been developed to detect the presence of these pathogens in clinical samples, including enzyme-linked immunosorbent assays (ELISAs), lateral flow assays (LFAs) and reverse transcriptase-polymerase chain reaction (RT-PCR). Most of these assays are performed in centralized laboratories due to the need for specialized equipment, such as PCR thermal cyclers and dedicated infrastructure. More recently, molecular methods have been developed which can be performed at a constant temperature, termed isothermal amplification, negating the need for expensive thermal cycling equipment. In most cases, isothermal amplification can now be carried out in as little as 5-20 min. These methods can potentially be used as inexpensive point of care (POC) tests and in-field deployable applications, thus decentralizing the molecular diagnosis of arboviral disease. This review focuses on the latest developments in isothermal amplification technology and detection techniques that have been applied to arboviral diagnostics and highlights future applications of these new technologies.

9.
J Immunol ; 183(9): 5728-37, 2009 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-19812207

RESUMO

Inflammation following tissue damage promotes lymphocyte recruitment, tissue remodeling, and wound healing while maintaining self tolerance. Endogenous signals associated with tissue damage and cell death have been proposed to initiate and instruct immune responses following injury. In this study, we have examined the effects of elevated levels of a candidate endogenous danger signal, heat shock cognate protein 70 (hsc70), on stimulation of inflammation and autoimmunity following cell damage. We find that damage to pancreatic beta cells expressing additional cytosolic hsc70 leads to an increased incidence of diabetes in a transgenic mouse model. Steady-state levels of activated APC and T cell populations in the draining lymph node were enhanced, which further increased following streptozotocin-induced beta cell death. In addition, proinflammatory serum cytokines, and lymphocyte recruitment were increased in hsc70 transgenic mice. Islet Ag-specific T cells underwent a greater extent of proliferation in the lymph nodes of mice expressing hsc70 following beta cell damage, suggesting elevated Ag presentation following release of Ag in the presence of hsc70. These findings suggest that an elevated content of hsc70 in cells undergoing necrotic or apoptotic cell death can increase the extent of sterile inflammation and increase the susceptibility to autoimmunity.


Assuntos
Diabetes Mellitus Experimental/imunologia , Diabetes Mellitus Experimental/patologia , Proteínas de Choque Térmico HSC70/biossíntese , Proteínas de Choque Térmico HSC70/genética , Ilhotas Pancreáticas/imunologia , Ilhotas Pancreáticas/patologia , Animais , Doenças Autoimunes/epidemiologia , Doenças Autoimunes/genética , Doenças Autoimunes/patologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/patologia , Bovinos , Morte Celular/genética , Morte Celular/imunologia , Movimento Celular/genética , Movimento Celular/imunologia , Citosol/imunologia , Citosol/metabolismo , Diabetes Mellitus Experimental/epidemiologia , Diabetes Mellitus Experimental/genética , Modelos Animais de Doenças , Incidência , Ilhotas Pancreáticas/metabolismo , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Transgênicos , Ratos
10.
Nat Med ; 9(12): 1469-76, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14625545

RESUMO

Pathogens or pathogen-associated molecular patterns can signal to cells of the innate immune system and trigger effective adaptive immunity. However, relatively little is known about how the innate immune system detects tissue injury or necrosis. Evidence suggests that the release of heat-shock proteins (HSPs) may provide adjuvant-like signals, but the ability of HSPs to promote activation or tolerance in vivo has not been addressed. In this study we show that Hsp70 promotes dendritic cell (DC) function and, together with antigen, triggers autoimmune disease in vivo.


Assuntos
Células Apresentadoras de Antígenos/imunologia , Proteínas de Choque Térmico HSP70/imunologia , Linfócitos T/imunologia , Animais , Autoimunidade , Sequência de Bases , Antígenos CD40/metabolismo , DNA Complementar/genética , Diabetes Mellitus Tipo 1/etiologia , Diabetes Mellitus Tipo 1/imunologia , Humanos , Tolerância Imunológica , Técnicas In Vitro , Interleucina-12/biossíntese , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Proteínas Recombinantes/imunologia , Transdução de Sinais
11.
PLoS One ; 15(1): e0227550, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31951602

RESUMO

BACKGROUND: The family flaviviridae and alphaviridae contain a diverse group of pathogens that cause significant morbidity and mortality worldwide. Diagnosis of the virus responsible for disease is essential to ensure patients receive appropriate clinical management. Very few real-time RT-PCR based assays are able to detect the presence of all members of these families using a single primer and probe set. We have developed a novel chemistry, 3base, which simplifies the viral nucleic acids allowing the design of RT-PCR assays capable of pan-family identification. METHODOLOGY/PRINCIPAL FINDING: Synthetic constructs, viral nucleic acids, intact viral particles and characterised reference materials were used to determine the specificity and sensitivity of the assays. Synthetic constructs demonstrated the sensitivities of the pan-flavivirus detection component were in the range of 13 copies per PCR. The pan-alphavirus assay had a sensitivity range of 10-25 copies per reaction depending on the viral strain. Lower limit of detection studies using whole virus particles demonstrated that sensitivity for assays was in the range of 1-2 copies per reaction. No cross reactivity was observed with a number of commonly encountered viral strains. Proficiency panels showed 100% concordance with the expected results and the assays performed as well as, if not better than, other assays used in laboratories worldwide. After initial assay validation the pan-viral assays were then tested during the 2016-2017 Vanuatu dengue-2 outbreak. Positive results were detected in 116 positives from a total of 187 suspected dengue samples. CONCLUSIONS/SIGNIFICANCE: The pan-viral screening assays described here utilise a novel 3base technology and are shown to provide a sensitive and specific method to screen and thereafter speciate flavi- and/or alpha- viruses in clinical samples. The assays performed well in an outbreak situation and can be used to detect positive clinical samples containing any flavivirus or alphavirus in approximately 3 hours 30 minutes.


Assuntos
Vírus da Dengue/genética , Vírus da Dengue/isolamento & purificação , Dengue/epidemiologia , Surtos de Doenças , Reação em Cadeia da Polimerase em Tempo Real , Sequência de Bases , Vírus da Dengue/fisiologia , Humanos , Limite de Detecção , Vanuatu/epidemiologia
12.
Sci Rep ; 10(1): 21244, 2020 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-33277521

RESUMO

Breast cancer metastasis occurs via blood and lymphatic vessels. Breast cancer cells 'educate' lymphatic endothelial cells (LECs) to support tumor vascularization and growth. However, despite known metabolic alterations in breast cancer, it remains unclear how lymphatic endothelial cell metabolism is altered in the tumor microenvironment and its effect in lymphangiogenic signaling in LECs. We analyzed metabolites inside LECs in co-culture with MCF-7, MDA-MB-231, and SK-BR-3 breast cancer cell lines using [Formula: see text] nuclear magnetic resonance (NMR) metabolomics, Seahorse, and the spatial distribution of metabolic co-enzymes using optical redox ratio imaging to describe breast cancer-LEC metabolic crosstalk. LECs co-cultured with breast cancer cells exhibited cell-line dependent altered metabolic profiles, including significant changes in lactate concentration in breast cancer co-culture. Cell metabolic phenotype analysis using Seahorse showed LECs in co-culture exhibited reduced mitochondrial respiration, increased reliance on glycolysis and reduced metabolic flexibility. Optical redox ratio measurements revealed reduced NAD(P)H levels in LECs potentially due to increased NAD(P)H utilization to maintain redox homeostasis. [Formula: see text]-labeled glucose experiments did not reveal lactate shuttling into LECs from breast cancer cells, yet showed other [Formula: see text] signals in LECs suggesting internalized metabolites and metabolic exchange between the two cell types. We also determined that breast cancer co-culture stimulated lymphangiogenic signaling in LECs, yet activation was not stimulated by lactate alone. Increased lymphangiogenic signaling suggests paracrine signaling between LECs and breast cancer cells which could have a pro-metastatic role.


Assuntos
Neoplasias da Mama/metabolismo , Células Endoteliais/metabolismo , Metabolômica/métodos , Linhagem Celular Tumoral , Técnicas de Cocultura , Feminino , Humanos , Linfangiogênese/genética , Linfangiogênese/fisiologia , Células MCF-7 , Oxirredução , Transdução de Sinais/genética , Transdução de Sinais/fisiologia
13.
Cancer Immunol Res ; 8(4): 544-555, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32047025

RESUMO

High-grade serous ovarian cancer (HGSC), the principal cause of death from gynecologic malignancies in the world, has not significantly benefited from advances in cancer immunotherapy. Although HGSC infiltration by lymphocytes correlates with superior survival, the nature of antigens that can elicit anti-HGSC immune responses is unknown. The goal of this study was to establish the global landscape of HGSC tumor-specific antigens (TSA) using a mass spectrometry pipeline that interrogated all reading frames of all genomic regions. In 23 HGSC tumors, we identified 103 TSAs. Classic TSA discovery approaches focusing only on mutated exonic sequences would have uncovered only three of these TSAs. Other mutated TSAs resulted from out-of-frame exonic translation (n = 2) or from noncoding sequences (n = 7). One group of TSAs (n = 91) derived from aberrantly expressed unmutated genomic sequences, which were not expressed in normal tissues. These aberrantly expressed TSAs (aeTSA) originated primarily from nonexonic sequences, in particular intronic (29%) and intergenic (22%) sequences. Their expression was regulated at the transcriptional level by variations in gene copy number and DNA methylation. Although mutated TSAs were unique to individual tumors, aeTSAs were shared by a large proportion of HGSCs. Taking into account the frequency of aeTSA expression and HLA allele frequencies, we calculated that, in Caucasians, the median number of aeTSAs per tumor would be five. We conclude that, in view of their number and the fact that they are shared by many tumors, aeTSAs may be the most attractive targets for HGSC immunotherapy.


Assuntos
Antígenos de Neoplasias/análise , Biomarcadores Tumorais/análise , Cistadenocarcinoma Seroso/patologia , Imunoterapia/métodos , Mutação , Neoplasias Ovarianas/patologia , Proteogenômica/métodos , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/metabolismo , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Cistadenocarcinoma Seroso/genética , Cistadenocarcinoma Seroso/metabolismo , Feminino , Humanos , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/metabolismo
14.
Elife ; 92020 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-32314731

RESUMO

HLA-restricted T cell responses can induce antitumor effects in cancer patients. Previous human T cell research has largely focused on the few HLA alleles prevalent in a subset of ethnic groups. Here, using a panel of newly developed peptide-exchangeable peptide/HLA multimers and artificial antigen-presenting cells for 25 different class I alleles and greater than 800 peptides, we systematically and comprehensively mapped shared antigenic epitopes recognized by tumor-infiltrating T lymphocytes (TILs) from eight melanoma patients for all their class I alleles. We were able to determine the specificity, on average, of 12.2% of the TILs recognizing a mean of 3.1 shared antigen-derived epitopes across HLA-A, B, and C. Furthermore, we isolated a number of cognate T cell receptor genes with tumor reactivity. Our novel strategy allows for a more complete examination of the immune response and development of novel cancer immunotherapy not limited by HLA allele prevalence or tumor mutation burden.


The immune system is the body's way of defending itself, offering protection against diseases such as cancer. But to remove the cancer cells, the immune system must be able to identify them as different from the rest of the body. All cells break down proteins into shorter fragments, known as peptides, that are displayed on the cell surface by a protein called human leukocyte antigen, HLA for short. Cancer cells display distinctive peptides on their surface as they generate different proteins to those of healthy cells. Immune cells called T cells use these abnormal peptides to identify the cancer so that it can be destroyed. Sometimes T cells can lack the right equipment to detect abnormal peptides, allowing cancer cells to hide from the immune system. However, T cells can be trained through a treatment called immunotherapy, which provides T cells with new tools so that they can spot the peptides displayed by HLA on the previously 'hidden' cancer cells. There are many different forms of HLA, each of which can display different peptides. Current research in immunotherapy commonly targets only a subset of HLA forms, and not all cancer patients have these types. This means that immunotherapy research is only likely to be of most benefit to a limited number of patients. Immunotherapy could be made effective for more people if new cancer peptides that are displayed by the other 'under-represented' forms of HLA were identified. Murata, Nakatsugawa et al. have now used T cells that were taken from tumors in eight patients with melanoma, which is a type of skin cancer. A library of fluorescent HLA-peptides was generated ­ using a new, simplified methodology ­ with 25 forms of HLA that displayed over 800 peptides. T cells were then mixed with the library to identify which HLA-peptides they can target. As a result, Murata, Nakatsugawa et al. found the cancer targets of around 12% of the tumor-infiltrating T cells tested, including those from under-represented forms of HLA. Consequently, these findings could be used to develop new immunotherapies that can treat more patients.


Assuntos
Antígenos de Neoplasias/imunologia , Epitopos de Linfócito T/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Linfócitos do Interstício Tumoral/imunologia , Melanoma/imunologia , Humanos , Receptores de Antígenos de Linfócitos T/imunologia
15.
Int J Dev Biol ; 52(8): 1033-42, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18956336

RESUMO

Culture of mesenchymal stem cells (MSCs) under conditions promoting proliferation and differentiation, while supporting genomic and epigenetic stability, is essential for therapeutic use. We report here the extent of genome-wide DNA gains and losses and of DNA methylation instability on 170 cancer-related promoters in bone marrow (BM) MSCs during culture to late passage in medium containing fetal bovine serum (FBS) or autologous serum (AS). Comparative genomic hybridization indicates that expansion of BMMSCs elicits primarily telomeric deletions in a subpopulation of cells, the extent of which varies between donors. However, late passage cultures in AS consistently display normal DNA copy numbers. Combined bisulfite restriction analysis and bisulfite sequencing show that although DNA methylation states are overall stable in culture, AS exhibits stronger propensity than FBS to maintain unmethylated states. Comparison of DNA methylation in BMMSCs with freshly isolated and cultured adipose stem cells (ASCs) also reveals that most genes unmethylated in both BMMSCs and ASCs in early passage are also unmethylated in uncultured ASCs. We conclude that (i) BMMSCs expanded in AS or FBS may display localized genetic alterations, (ii) AS tends to generate more consistent genomic backgrounds and DNA methylation patterns, and (iii) the unmethylated state of uncultured MSCs is more likely to be maintained in culture than the methylated state.


Assuntos
Meios de Cultura , Epigênese Genética , Instabilidade Genômica , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Adipócitos/citologia , Adipócitos/metabolismo , Células-Tronco Adultas/citologia , Células-Tronco Adultas/metabolismo , Animais , Células da Medula Óssea/citologia , Células da Medula Óssea/metabolismo , Bovinos , Técnicas de Cultura de Células , Hibridização Genômica Comparativa , Metilação de DNA , Dosagem de Genes , Humanos , Especificidade da Espécie
16.
Trop Med Infect Dis ; 4(4)2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31683788

RESUMO

Leishmaniasis is caused by the flagellated protozoan Leishmania, and is a neglected tropical disease (NTD), as defined by the World Health Organisation (WHO). Bisulphite conversion technology converts all genomic material to a simplified form during the lysis step of the nucleic acid extraction process, and increases the efficiency of multiplex quantitative polymerase chain reaction (qPCR) reactions. Through utilization of qPCR real-time probes, in conjunction with bisulphite conversion, a new duplex assay targeting the 18S rDNA gene region was designed to detect all Leishmania species. The assay was validated against previously extracted DNA, from seven quantitated DNA and cell standards for pan-Leishmania analytical sensitivity data, and 67 cutaneous clinical samples for cutaneous clinical sensitivity data. Specificity was evaluated by testing 76 negative clinical samples and 43 bacterial, viral, protozoan and fungal species. The assay was also trialed in a side-by-side experiment against a conventional PCR (cPCR), based on the Internal transcribed spacer region 1 (ITS1 region). Ninety-seven percent of specimens from patients that previously tested positive for Leishmania were positive for Leishmania spp. with the bisulphite conversion assay, and a limit of detection (LOD) of 10 copies per PCR was achieved, while the LOD of the ITS1 methodology was 10 cells/1000 genomic copies per PCR. This method of rapid, accurate and simple detection of Leishmania can lead to improved diagnosis, treatment and public health outcomes.

17.
J Clin Virol ; 42(1): 22-6, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18262463

RESUMO

BACKGROUND: It is well established that human papillomavirus (HPV) infection is highly related to the development of precursor lesions of cervical cancer and uterine cancers. However, for a pre-cancerous lesion to develop, a persistent infection with a high-risk type HPV is necessary. The Digene Hybrid Capture II (hcII) assay is the only FDA approved method used in conjunction with cytology for HPV screening of women older than 30. The hcII has moderate sensitivity (64.7%) and is dependent on the cellular content of samples, rendering occasionally false positive and false negative results. OBJECTIVE: This study aims to evaluate the performance of a new HPV diagnostic kit (High-Risk HPV detection kit, manufactured by Human Genetic Signatures (HGS), Sydney, Australia). METHODS: The method under evaluation was assessed by comparing the results obtained from testing 834 cervical specimens with the HGS method and the Digene hcII method, using genotyping as the reference standard. RESULTS: Results of the study showed that the specificity and positive predictive value of the HGS High-Risk HPV detection test are significantly greater than those of the Digene hcII test. Overall the HGS HPV assay provides a more accurate system for the detection of high-risk HPV strains, with simpler technical use compared with PCR-sequencing methods.


Assuntos
Papillomaviridae/classificação , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/diagnóstico , Infecções por Papillomavirus/virologia , Austrália , Feminino , Humanos , Hibridização de Ácido Nucleico/métodos , Reação em Cadeia da Polimerase/métodos , Valor Preditivo dos Testes , Kit de Reagentes para Diagnóstico , Sensibilidade e Especificidade
18.
Sci Immunol ; 3(30)2018 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-30552102

RESUMO

Antigen recognition by T cells bearing αß T cell receptors (TCRs) is restricted by major histocompatibility complex (MHC). However, how antigens are recognized by T cells bearing γδ TCRs remains unclear. Although γδ T cells can recognize nonclassical MHC, it is generally thought that recognition of antigens is not MHC restricted. Here, we took advantage of an in vitro system to generate antigen-specific human T cells and show that melanoma-associated antigens, MART-1 and gp100, can be recognized by γδ T cells in an MHC-restricted fashion. Cloning and transferring of MART-1-specific γδ TCRs restored the specific recognition of the initial antigen MHC/peptide reactivity and conferred antigen-specific functional responses. A crystal structure of a MART-1-specific γδ TCR, together with MHC/peptide, revealed distinctive but similar docking properties to those previously reported for αß TCRs, recognizing MART-1 on HLA-A*0201. Our work shows that antigen-specific and MHC-restricted γδ T cells can be generated in vitro and that MART-1-specific γδ T cells can also be found and cloned from the naïve repertoire. These findings reveal that classical MHC-restricted human γδ TCRs exist in the periphery and have the potential to be used in developing of new TCR-based immunotherapeutic approaches.


Assuntos
Antígeno MART-1/imunologia , Melanoma/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Linfócitos T/imunologia , Adulto , Células Cultivadas , Cristalografia por Raios X , Humanos , Antígeno MART-1/química , Modelos Moleculares , Receptores de Antígenos de Linfócitos T gama-delta/química
19.
Cancer Med ; 5(3): 389-97, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26806010

RESUMO

Within PrefHer (NCT01401166), patients and healthcare professionals (HCPs) preferred subcutaneous (SC) over intravenous (IV) trastuzumab. We undertook a prospective, observational time and motion study to quantify patients' time in infusion chairs and active HCP time in PrefHer. Patients with HER2-positive early breast cancer received four adjuvant cycles of SC trastuzumab (600 mg fixed dose via SC single-use injection device [SID, Cohort 1] or SC handheld syringe [HHS, Cohort 2]) then four cycles of standard IV trastuzumab or the reverse sequence. Generic case report forms for IV and SC management, both in the treatment room and the drug preparation area, were tailored to reflect center practices. Patient chair time and active HCP time were recorded. We compared pooled Cohort 1 + 2 IV with Cohort 1 SC SID and Cohort 2 SC HHS mean times across eight countries and individually within them utilizing a random intercept generalized linear mixed-effects model. Per session, the SC SID saved a mean of 57 min of patient chair time versus IV (range across countries: 47-86; P < 0.0001); the SC HHS saved 55 min (40-81; P < 0.0001). Active HCP time was reduced by a mean of 13 min per session with the SC SID (range across countries: 4-16; P < 0.0001) and 17 min with the SC HHS (5-28; P < 0.0001) versus IV. SC trastuzumab, delivered via SID or HHS, saved patient chair and active HCP times versus IV infusion, supporting a transition to either SC method.


Assuntos
Antineoplásicos/administração & dosagem , Neoplasias da Mama/tratamento farmacológico , Receptor ErbB-2/genética , Trastuzumab/administração & dosagem , Antineoplásicos/uso terapêutico , Neoplasias da Mama/genética , Esquema de Medicação , Feminino , Humanos , Injeções Intravenosas , Injeções Subcutâneas , Estudos Prospectivos , Estudos de Tempo e Movimento , Trastuzumab/uso terapêutico , Resultado do Tratamento
20.
Mol Endocrinol ; 16(2): 213-20, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11818495

RESUMO

Inhibin is composed of an alpha- and a beta-subunit. Transgenic studies assigned a tumor-suppressive role to the inhibin alpha-subunit, and in human prostate cancer inhibin alpha-subunit gene expression was down-regulated. This study examined the inhibin alpha-subunit gene promoter and gene locus to determine whether promoter hypermethylation or LOH occurred in DNA from prostate cancer. The 5'-untranslated region of the human inhibin alpha-subunit gene was sequenced and shown to be highly homologous to the bovine, rat, and mouse inhibin alpha-subunit promoter sequences. A 135-bp region of the human promoter sequence that continued a cluster of CpG sites was analyzed for hypermethylation. Significant (P < 0.001) hypermethylation of the inhibin alpha-subunit gene promoter occurred in DNA from Gleason pattern 3, 4, and 5 carcinomas compared with nonmalignant tissue samples. A subset of the carcinomas with a cribriform pattern were unmethylated. LOH at 2q32-36, the chromosomal region harboring the inhibin alpha-subunit gene, was observed in 42% of prostate carcinomas. These data provide the first demonstration that promoter hypermethylation and LOH are associated with the inhibin alpha-subunit gene and gene locus in prostate cancer.


Assuntos
Metilação de DNA , Inibinas/genética , Neoplasias da Próstata/genética , Regiões 5' não Traduzidas/genética , Animais , Sequência de Bases , Biópsia , Bovinos , Cromossomos Humanos Par 2/genética , Humanos , Perda de Heterozigosidade/genética , Masculino , Camundongos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Regiões Promotoras Genéticas/genética , Neoplasias da Próstata/patologia , Ratos , Homologia de Sequência do Ácido Nucleico
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