Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
1.
Scand J Immunol ; 94(3): e13089, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35971920

RESUMEN

CD226 and the inhibitory T-cell immunoglobulin and ITIM domain (TIGIT) belong to a co-stimulatory receptor system found in both T and natural killer cells. Although data from genome-wide studies have suggested a strong association between the CD226 locus and multiple autoimmune diseases, the understanding of the balance of CD226/TIGIT axis during the activation of human T-cell subpopulation remains incomplete. In this study, we aimed to compare pre- and post-stimulation expression profiles of CD226 and TIGIT with those of CD28 in human CD4+ and CD8+ T-cell subpopulations using flow cytometry. The impact of the CD226 single nucleotide polymorphism, rs763361, on cell surface CD226 expression and effector cytokine secretion was also examined. Peripheral blood mononuclear cells from healthy blood donors (n = 65) were studied. Most naïve CD4+ and CD8+ T-cells did not express CD226 and TIGIT, predominantly upregulating activating receptors following stimulation. Memory CD4+ T-cells exhibited a balanced expression of activating and inhibitory receptors, pre- and post-stimulation. In contrast, memory CD8+ T-cells predominantly expressed TIGIT. The rs763361 TT genotype was associated with both a reduction in CD226 expression on the cell surface of CD4+ memory T-cells (P = .004) and increased interleukin-17A secretion from activated T-cells (P = .036). Description of different expression patterns on T lymphocyte subpopulations provided in this work will lead to a more comprehensive understanding of the role of the CD226/TIGIT axis in control over T-cell activation and suppression.


Asunto(s)
Antígenos de Diferenciación de Linfocitos T , Linfocitos T CD4-Positivos , Linfocitos T CD8-positivos , Receptores Inmunológicos , Antígenos de Diferenciación de Linfocitos T/genética , Humanos , Receptores Inmunológicos/genética , Subgrupos de Linfocitos T/metabolismo
2.
Cytometry A ; 93(11): 1150-1156, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30343519

RESUMEN

B cells with regulatory properties have been recently identified and described in different immune disorders, including autoimmunity, infection, cancer, and allergy. in vitro studies of regulatory B cells are usually performed following prolonged cell culture and stimulation in order to obtain B cells capable of IL-10 secretion. We describe the isolation of viable IL-10-positive B cells directly from ex vivo unstimulated samples using the IL-10 secretion assay from Miltenyi Biotec, which was originally designed for IL-10-positive T cell analysis and isolation. IL-10-positive B cells from unstimulated samples represented approximately 2% of all B cells in healthy individuals, suppressed T cell proliferation and were enriched for surface markers of B cell activation. This tool has a potential to boost functional studies of IL-10-secreting B cells in health and disease. © 2018 International Society for Advancement of Cytometry.


Asunto(s)
Linfocitos B Reguladores/inmunología , Interleucina-10/inmunología , Activación de Linfocitos/inmunología , Proliferación Celular/fisiología , Citometría de Flujo/métodos , Humanos , Fenotipo , Linfocitos T/inmunología
3.
Med Microbiol Immunol ; 205(3): 231-9, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26696529

RESUMEN

Some individuals remain uninfected despite repeated exposure to HIV. This protection against HIV has been partly associated with altered T cell subset distributions and CCR5 expression levels. However, the majority of studies have been conducted in sexually exposed subjects. We aimed to assess whether HIV infection and intravenous drug use were associated with differences in CCR5 expression, immune activation on the CD4+ and CD8+ T cells and T cell distribution among Caucasian persons who inject drugs (PWIDs). Analyses of the data from 41 HIV-positive PWIDs, 47 HIV-exposed seronegative PWIDs (ESNs) and 47 age- and gender-matched HIV-negative non-drug users are presented. Of all of the study subjects, 111 (82 %) were male, and the median age was 29 years. T cell phenotyping was performed in peripheral blood mononuclear cells with multicolour flow cytometry using anti-CD3, CD4, CD8, CD45RA, CD45RO, HLA-DR and CCR5 antibodies. The ESNs exhibited greater levels of immune activation and higher percentages of CD4+ CD45RA+RO+ and CD8+ CD45RA+RO+ cells compared to the controls but not the HIV-positive people. The CCR5 expression on the CD4+ T cell subsets in the ESNs was lower than that in the controls but similar to that the HIV positives. The percentages of CCR5+ T cells were similar in all study groups and in most of the studied cell populations. Intravenous drug use was similarly associated with differences in T cell subset distributions and CCR5 expression among both the HIV-positive and HIV-negative PWIDs compared with the controls.


Asunto(s)
Exposición a Riesgos Ambientales , Infecciones por VIH/inmunología , Receptores CCR5/análisis , Abuso de Sustancias por Vía Intravenosa/complicaciones , Subgrupos de Linfocitos T/química , Subgrupos de Linfocitos T/inmunología , Femenino , Citometría de Flujo , Humanos , Inmunofenotipificación , Masculino
4.
J Immunotoxicol ; 21(1): 2373247, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-39066679

RESUMEN

Molecular mimicry has been proposed to be a possible mechanism of induction of autoimmunity. In some cases, it is believed that such events could lead to a disease such as Type 1 diabetes (T1D). One of the primary MHC-I epitopes in the non-obese diabetic (NOD) mouse model of T1D has been identified as a peptide from the islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP) protein. In humans, the most common MHC-I model allele is HLA-A02; based on this, the study here identified a potential HLA-A0201-restricted human IGRP epitope as YLKTNLFLFL and also found a homologous A0201-restricted peptide in an Enterococcal protein. Using cells obtained from healthy human donors, it was seen that after a 2-week incubation with the synthetic bacterial protein, healthy A0201+ donor CD8+ cells displayed increased staining for human IGRP-peptide-dextramer. On the other hand, in control cultures, no significant levels of dextramer-staining CD8+ T-cells were detectable. From these outcomes, it is possible to conclude that certain bacterial proteins may initiate CD8+ T-cell-mediated immune reaction toward homologous human antigens.


Asunto(s)
Antígenos Bacterianos , Linfocitos T CD8-positivos , Reacciones Cruzadas , Diabetes Mellitus Tipo 1 , Epítopos de Linfocito T , Glucosa-6-Fosfatasa , Antígeno HLA-A2 , Humanos , Diabetes Mellitus Tipo 1/inmunología , Antígeno HLA-A2/inmunología , Antígeno HLA-A2/metabolismo , Antígenos Bacterianos/inmunología , Glucosa-6-Fosfatasa/inmunología , Glucosa-6-Fosfatasa/genética , Reacciones Cruzadas/inmunología , Epítopos de Linfocito T/inmunología , Linfocitos T CD8-positivos/inmunología , Animales , Ratones , Imitación Molecular/inmunología , Ratones Endogámicos NOD , Proteínas Bacterianas/inmunología , Células Cultivadas
5.
Front Immunol ; 9: 2707, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30515176

RESUMEN

Vitiligo is a chronic multifactorial depigmentation disorder characterized by the destruction and functional loss of melanocytes. Although a direct cytotoxic T cell attack is thought to be responsible for melanocyte damage, the events leading to the loss of self-tolerance toward melanocytic antigens are not understood. This research aimed to identify novel cellular and molecular factors that participate in vitiligo pathogenesis through the application of gene expression and immunofluorescence analysis of skin biopsy samples along with immunophenotyping of circulating cells. Our study provides insights into the mechanisms involved in melanocyte destruction. The upregulation of stress-ligand MICA/MICB, recognized by activating receptors on innate and innate-like T cells, imply involvement of lymphoid stress surveillance responses in vitiligo lesions. A simultaneous increase in the expression of transcription factor EOMES that is characteristic for innate-like virtual memory T cells, suggest a similar scenario. Local lymphoid stress surveillance has been previously associated with the amplification of systemic humoral responses that were mirrored in our study by increased T follicular helper cells and switched memory B cell proportions in patients with active vitiligo. In addition, microtubule-associated protein light chain 3 staining was compatible with the activation of autophagy in keratinocytes and in the remaining melanocytes of vitiligo lesional skin.


Asunto(s)
Linfocitos B/inmunología , Inmunidad Humoral , Estrés Fisiológico/inmunología , Linfocitos T Colaboradores-Inductores/inmunología , Vitíligo/inmunología , Adulto , Autofagia/inmunología , Linfocitos B/patología , Femenino , Antígenos de Histocompatibilidad Clase I/inmunología , Humanos , Queratinocitos/inmunología , Queratinocitos/patología , Masculino , Melanocitos/inmunología , Melanocitos/patología , Persona de Mediana Edad , Proteínas de Dominio T Box/inmunología , Linfocitos T Colaboradores-Inductores/patología , Vitíligo/patología
6.
Sci Rep ; 7(1): 7553, 2017 08 08.
Artículo en Inglés | MEDLINE | ID: mdl-28790368

RESUMEN

Psoriasis is a chronic inflammatory disease that affects skin and is associated with systemic inflammation and many serious comorbidities ranging from metabolic syndrome to cancer. Important discoveries about psoriasis pathogenesis have enabled the development of effective biological treatments blocking the T helper 17 pathway. However, it has not been settled whether psoriasis is a T cell-mediated autoimmune disease or an autoinflammatory disorder that is driven by exaggerated innate immune signalling. Our comparative gene expression and hierarchical cluster analysis reveal important gene circuits involving innate receptors. Innate immune activation is indicated by increased absent in melanoma 2 (AIM2) inflammasome gene expression and active caspase 1 staining in psoriatic lesional skin. Increased eomesodermin (EOMES) expression in lesional and non-lesional skin is suggestive of innate-like virtual memory CD8+ T cell infiltration. We found that signs of systemic inflammation were present in most of the patients, correlated with the severity of the disease, and pointed to IL-6 involvement in the pathogenesis of psoriatic arthritis. Among the circulating T cell subpopulations, we identified a higher proportion of terminally differentiated or senescent CD8+ T cells, especially in patients with long disease duration, suggesting premature immunosenescence and its possible implications for psoriasis co-morbidities.


Asunto(s)
Inmunidad Innata/inmunología , Inmunosenescencia/inmunología , Psoriasis/inmunología , Piel/inmunología , Adulto , Estudios de Casos y Controles , Citocinas/sangre , Citocinas/genética , Citocinas/metabolismo , Femenino , Expresión Génica/inmunología , Humanos , Inmunidad Innata/genética , Inmunosenescencia/genética , Inflamación/genética , Inflamación/inmunología , Masculino , Persona de Mediana Edad , Psoriasis/sangre , Psoriasis/genética , Piel/metabolismo , Piel/patología , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo , Adulto Joven
7.
Viral Immunol ; 29(8): 464-470, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27564643

RESUMEN

Intravenous drug use (IDU) is one of the most important transmission routes for blood borne viruses, including human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV). These infections alter the subset distributions of T cells; however, knowledge of such effects during HIV, HBV, and or HCV coinfection is limited. Therefore, we aimed to evaluate any associations between T cell distribution and the presence of HIV, HBV, and HCV coinfections among persons who inject drugs (PWID). Blood samples from 88 Caucasian PWID (mean age 30; 82% male) and 47 age-matched subjects negative for all three infections (mean age of 29; 83% male) were analyzed. The T cell markers CD3, CD4, CD8, CD45RA, CCR7, HLA-DR, and CCR5 were assessed using flow cytometry. Of the PWID, 40% were HIV+HBV+HCV+, 20% HBV+HCV+, 19% HCV+, and 13% negative for all three infections. The HIV+HBV+HCV+ PWID had lower percentages of CD4+ and higher percentages of CD8+ cells compared to triple negative PWID (p < 0.001 in all cases). The only difference between HBV+HCV+ with triple negative PWID was the lower CD4+ cell percentages among the former (52.1% and 58.6%, p = 0.021). Triple negative PWID had higher immune activation and number of CCR5+ cells compared to the controls. We suggest that the altered T cell subset distribution among PWID is mainly triggered by HIV infection and or IDU, while HBV and or HCV seropositivity has minimal additional effects on CD4+ cell distribution.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA