Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Cells ; 13(7)2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38607032

RESUMO

Coevolution of hosts and their parasites has shaped heterogeneity of effector hemocyte types, providing immune defense reactions with variable effectiveness. In this work, we characterize hemocytes of Drosophila willistoni, a species that has evolved a cellular immune system with extensive variation and a high degree of plasticity. Monoclonal antibodies were raised and used in indirect immunofluorescence experiments to characterize hemocyte subpopulations, follow their functional features and differentiation. Pagocytosis and parasitization assays were used to determine the functional characteristics of hemocyte types. Samples were visualized using confocal and epifluorescence microscopy. We identified a new multinucleated giant hemocyte (MGH) type, which differentiates in the course of the cellular immune response to parasitoids. These cells differentiate in the circulation through nuclear division and cell fusion, and can also be derived from the central hematopoietic organ, the lymph gland. They have a binary function as they take up bacteria by phagocytosis and are involved in the encapsulation and elimination of the parasitoid. Here, we show that, in response to large foreign particles, such as parasitoids, MGHs differentiate, have a binary function and contribute to a highly effective cellular immune response, similar to the foreign body giant cells of vertebrates.


Assuntos
Drosophila , Parasitos , Animais , Diferenciação Celular , Fagocitose , Imunidade Celular
2.
Bioconjug Chem ; 34(10): 1738-1753, 2023 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-37606258

RESUMO

The complex immunopathology ofMycobacterium tuberculosis(Mtb) is one of the main challenges in developing a novel vaccine against this pathogen, particularly regarding eliciting protection against both active and latent stages. Multistage vaccines, which contain antigens expressed in both phases, represent a promising strategy for addressing this issue, as testified by the tuberculosis vaccine clinical pipeline. Given this approach, we designed and characterized a multistage peptide-based vaccine platform containing CD4+ and CD8+ T cell epitopes previously validated for inducing a relevant T cell response against Mtb. After preliminary screening, CFP10 (32-39), GlfT2 (4-12), HBHA (185-194), and PPE15 (1-15) were selected as promising candidates, and we proved that the PM1 pool of these peptides triggered a T cell response in Mtb-sensitized human peripheral blood mononuclear cells (PBMCs). Taking advantage of the use of thiol-maleimide chemoselective ligation, we synthesized a multiepitope conjugate (Ac-CGHP). Our results showed a structure-activity relationship between the conjugation and a higher tendency to fold and assume an ordered secondary structure. Moreover, the palmitoylated conjugate (Pal-CGHP) comprising the same peptide antigens was associated with an enhanced cellular uptake in human and murine antigen-presenting cells and a better immunogenicity profile. Immunization study, conducted in BALB/c mice, showed that Pal-CGHP induced a significantly higher T cell proliferation and production of IFNγ and TNFα over PM1 formulated in the Sigma Adjuvant System.


Assuntos
Mycobacterium tuberculosis , Vacinas contra a Tuberculose , Tuberculose , Humanos , Animais , Camundongos , Leucócitos Mononucleares , Antígenos de Bactérias , Linfócitos T CD4-Positivos , Tuberculose/prevenção & controle , Linfócitos T CD8-Positivos , Epitopos de Linfócito T , Peptídeos
3.
Molecules ; 25(7)2020 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-32244444

RESUMO

Use of a Pictet-Spengler reaction of tryptamine and l-tryptophan methyl ester and subsequent reduction of the nitro group followed by further cyclocondensation with aryl aldehydes and formyl-substituted carboxylic acids, including ferrocene-based components, furnished a series of diastereomeric 6-aryl-substituted 5,6,8,9,14,14b-hexahydroindolo[2',3':3,4]pyrido[1-c]-quinazolines and 5,5b,17,18-tetrahydroindolo[2',3':3,4]pyrido[1,2-c]isoindolo[2,1-a]quinazolin-11-(15bH)-ones with the elements of central-, planar and conformational chirality. The relative configuration and the conformations of the novel polycyclic indole derivatives were determined by 1H- and 13C-NMR methods supplemented by comparative DFT analysis of the possible diastereomers. The structure of one of the pentacyclic methyl esters with defined absolute configuration "S" was also confirmed by single crystal X-ray diffraction measurement. Accounting for the characteristic substituent-dependent diastereoselective formation of the products multistep mechanisms were proposed on the basis of the results of DFT modeling. Preliminary in vitro cytotoxic assays of the products revealed moderate-to-significant antiproliferative effects against PANC-1-, COLO-205-, A-2058 and EBC-1 cell lines that proved to be highly dependent on the stereostructure and on the substitution pattern of the pending aryl substituent.


Assuntos
Carbolinas/química , Compostos Ferrosos/química , Metalocenos/química , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Carbolinas/síntese química , Carbolinas/farmacologia , Linhagem Celular Tumoral , Técnicas de Química Sintética , Teoria da Densidade Funcional , Compostos Ferrosos/síntese química , Compostos Ferrosos/farmacologia , Humanos , Metalocenos/síntese química , Metalocenos/farmacologia , Modelos Teóricos , Conformação Molecular , Estrutura Molecular , Análise Espectral , Relação Estrutura-Atividade
4.
Acta Vet Hung ; 61(4): 473-6, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23974936

RESUMO

A mouflon showing severe weight loss and cachexia was examined. The animal had horns and a male-like body frame but the preputial fur was missing. The scrotum was completely absent. Both testicles were located next to the inguinal canal under the skin, and appeared only slightly smaller than normal. The prepuce was located in a perianal position under the anus and it resembled a vulva. The penis was underdeveloped and curled up inside the prepuce like an enlarged clitoris. The bulbourethral region and the urinary bladder looked normal. The orifice of the urethra was located in its normal position, but the glans penis appeared deformed. Microscopic examination of the testicles revealed mild degeneration of the seminiferous tubules and a marked proliferation of the interstitial connective tissue with Leydig cells still present. There were no marked changes in the bulbar part of the penis but the apical part exhibited marked interstitial fibrosis. This is the first description of hypospadias and cryptorchidism in mouflon.


Assuntos
Criptorquidismo , Hipospadia , Animais , Masculino , Pênis , Escroto , Carneiro Doméstico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA