Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Scand J Immunol ; 98(5): e13318, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38441343

RESUMEN

T cell subsets (CD4 and CD8) play a prominent role in the development of chronic rhinosinusitis with nasal polyposis (CRSwNP). Colonization with Aspergillus flavus is recognized as a trigger for the growth of nasal polyps. The fungal proteins initiate the recruitment of T cells into the nasal mucosa, which contributes to the progression of nasal polyps. The study included 50 cases of CRSwNP and 50 healthy controls. Biopsies were subjected to KOH and culture for mycological investigation. We examined the changes in T helper (CD4+) and T cytotoxic (CD8+) in total T cells (CD3+) and expression of naive (CD45RA) and memory (CD45RO) cell markers in T cell subsets in peripheral blood mononuclear cells (PBMCs) challenged by A. flavus antigens in cases before and after treatment and in healthy controls by flow cytometry. Predominantly, A. flavus (86%) identified in nasal polyp biopsies of patients. An increased percentage of CD3+CD4+ T cells observed after A. flavus stimulation in patients when compared with healthy controls. The expression of CD4+CD45RA+ cells was significantly (P < .05) reduced in patients and increased CD4+CD45RO+ was observed upon stimulation with A. flavus in patients when compared with healthy control. Continuous exposure to inhaled fungal spores may induce aberrant immune responses to A. flavus spores, causing an allergic immunological reaction with high CD4+T cell responses, resulting in an unfavourable outcome. Elevated CD4+CD45RO+ T cells may transform the pathogenic response and highlight the chances of A. flavus reactive T cells involvement in prompting inflammation in CRSwNP.


Asunto(s)
Hipersensibilidad , Pólipos Nasales , Rinosinusitis , Humanos , Aspergillus flavus , Leucocitos Mononucleares , Subgrupos de Linfocitos T , Antígenos Comunes de Leucocito
2.
Microb Cell Fact ; 19(1): 215, 2020 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-33238997

RESUMEN

BACKGROUND: T helper (Th)17 and regulatory T (Treg) cells with toll-like receptor (TLR)-2 have been acknowledged to play a critical role in chronic rhinosinusitis with nasal polyposis (CRSwNP). However, its pathogenesis has been perplexed by conflicting reports on the role of Th17/Treg cells in patients of distinct ethnicities. We attempted to understand the role of Th responses induced during host defense against Aspergillus flavus. RESULTS: The percentages of Th17 (CD4+CD161+IL23R+) and Treg (CD4+CD25+FoxP3+) cell populations and various cytokine profiles in peripheral blood mononuclear cells (PBMCs) challenged by A. flavus antigens were characterized from 50 CRSwNP cases, before and after treatment, and in 50 healthy controls. TLR-2 expression was analyzed in tissues of cases and controls for disease co-relation. The major pathogen identified in our study was A. flavus by mycological investigations. A marked immune imbalance was noted with elevated Th17 and decreased Tregs in PBMCs of CRSwNP patients after A. flavus stimulation. Comparatively, interleukin (IL)-17 and IL-10 levels were increased, with low transforming growth factor (TGF)-ß levels in A. flavus stimulated PBMC supernatants of patients. The mRNA expression of TLR-2 in polyps of CRSwNP patients indicated significant (p = 0.001) upregulation in comparison to the controls. CONCLUSIONS: Our data highlights the excessive expression of TLR-2 in nasal polyps contributing to the imbalance in Th17/Tregs population in patients. After therapy, recovery of Tregs cells indicates restoration and tissue homeostasis, though high circulating CD4+CD161+ Th17 cells may continue to be a threat to patients predisposed to future recurrences. The constant exposure and tendency of A. flavus to colonize nasal cavities can lead to a Th17 driven airway inflammation. Dysregulated Th17 with TLR-2 promote resistance to treatment and progression to the chronicity of the disease.


Asunto(s)
Aspergilosis/inmunología , Citocinas/inmunología , Pólipos Nasales/inmunología , Linfocitos T Reguladores/inmunología , Células Th17/inmunología , Receptor Toll-Like 2/inmunología , Adolescente , Adulto , Aspergillus flavus , Enfermedad Crónica , Femenino , Regulación de la Expresión Génica , Interacciones Huésped-Patógeno , Humanos , Interleucina-10/inmunología , Interleucina-17/inmunología , Masculino , Persona de Mediana Edad , ARN Mensajero/inmunología , Rinitis/inmunología , Rinitis/microbiología , Sinusitis/inmunología , Sinusitis/microbiología , Receptor Toll-Like 2/genética , Adulto Joven
3.
Ann Lab Med ; 38(2): 125-131, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29214756

RESUMEN

BACKGROUND: Fungi, especially Aspergillus flavus, can cause chronic rhinosinusitis with nasal polyposis and modulate host innate immune components. The objective of this study was to examine the serum levels of T helper (Th) cell subset Th1, Th2, and Th17 cytokines and total IgE in patients having chronic rhinosinusitis with nasal polyposis and Aspergillus flavus infection. METHODS: A case-control study including 40 patients with chronic rhinosinusitis with nasal polyposis and 20 healthy controls was conducted. Aspergillus flavus infection was confirmed by standard potassium hydroxide (KOH) testing, culture, and PCR. Serum samples of all patients and controls were analyzed for various cytokines (interleukins [IL]-1ß, IL-2, IL-4, IL-6, IL-17, IL-21, IL-27, TGF-ß) and total IgE by ELISA. Data from patients with Aspergillus flavus infection and healthy volunteers were compared using the independent t-test and non-parametric Mann-Whitney U test. RESULTS: Aspergillus flavus infection was found in 31 (77.5%) patients with chronic rhinosinusitis with nasal polyposis. IL-1ß, IL-17, IL-21, and TGF-ß serum levels were significantly higher in these patients than in controls; however, IL-2, IL-4, IL-6, and IL-27 levels were lower. Compared with nine (22.5%) patients without Aspergillus flavus infection, IL-17 level was higher while IL-2 level was lower in patients with Aspergillus flavus infection. Total IgE was significantly higher in patients with Aspergillus flavus infection than in controls. CONCLUSIONS: High levels of IL-17 and its regulatory cytokines in patients with chronic rhinosinusitis with nasal polyposis infected by Aspergillus flavus raise a concern about effective disease management and therapeutic recovery. Surgical removal of the nasal polyp being the chief management option, the choice of post-operative drugs may differ in eosinophilic vs. non-eosinophilic nasal polyposis. The prognosis is likely poor, warranting extended care.


Asunto(s)
Aspergilosis/patología , Citocinas/sangre , Sinusitis/patología , Adolescente , Adulto , Anciano , Aspergilosis/sangre , Aspergilosis/microbiología , Aspergillus flavus/aislamiento & purificación , Estudios de Casos y Controles , Enfermedad Crónica , Femenino , Humanos , Inmunoglobulina E/sangre , Interleucina-12/sangre , Interleucina-17/sangre , Masculino , Persona de Mediana Edad , Pólipos Nasales/patología , Estudios Prospectivos , Sinusitis/sangre , Sinusitis/microbiología , Subgrupos de Linfocitos T/citología , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo , Adulto Joven
4.
Autoimmunity ; 50(3): 158-169, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28010120

RESUMEN

The association of interleukin-6 (IL-6)-174G > C (rs1800795) single nucleotide polymorphism (SNP) with the risk of acquiring rheumatoid arthritis (RA) is a relevant issue because of conflicting and consensus lacking reports published in literature. We investigated IL-6-174G > C promoter polymorphism in 34 RA patients, attending a tertiary care hospital in north India. We also performed a meta-analysis, of the previously published studies reporting this genetic relationship, in overall population, and independently in Asian and Caucasian ethnicities to further elucidate this association. A total of 13 studies, including the current one, involving 3291 RA cases and 3812 controls were analyzed. Out of the 13 studies, 6 were from Asian, 6 from Caucasian and 1 from a mixed population. Our case-control study showed significant association of IL-6-174G > C SNP with increased RA risk: allelic (OR = 3.750, 95% CI = 1.800-7.813, p < 0.001); dominant (OR = 2.800, 95% CI = 1.167-6.721, p = 0.021); and recessive (OR = 36.72, 95% CI = 2.004-672.7, p = 0.015). The meta-analysis revealed the increased RA risk associated with IL-6-174G > C SNP in overall population: allelic (OR = 1.650, 95% CI = 1.169-2.329, p = 0.004); homozygous (OR = 1.380, 95% CI = 0.906-2.101, p = 0.133); heterozygous (OR = 1.559, 95% CI = 1.001-2.428, p = 0.049); dominant (OR = 1.663, 95% CI = 1.078-2.567, p = 0.022); and recessive (OR = 1.366, 95% CI = 0.964-1.935, p = 0.079). Subgroup analysis also showed this polymorphism to be associated with increased RA risk in Asian population: allelic (OR = 3.724, 95% CI = 1.361-10.190, p = 0.010); dominant (OR = 3.823, 95% CI = 1.320-11.074, p = 0.013); and recessive (OR = 4.357, 95% CI = 1.634-11.623, p = 0.003), but not in Caucasian population. This meta-analysis shows that IL-6-174G > C SNP is significantly associated with increased RA risk in overall, and specifically in Asian population.


Asunto(s)
Artritis Reumatoide/genética , Artritis Reumatoide/patología , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Interleucina-6/genética , Polimorfismo de Nucleótido Simple , Alelos , Estudios de Casos y Controles , Genotipo , Humanos , Oportunidad Relativa , Grupos de Población/genética , Sesgo de Publicación
5.
Autoimmunity ; 49(3): 179-87, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26761187

RESUMEN

Pemphigus is an autoimmune blistering disorder of skin and/or mucosal surfaces characterized by intraepithelial lesions and immunoglobulin-G autoantibodies against desmogleins (proteins critical in cell-to-cell adhesion). Genetic, immunological, hormonal, and environmental factors are known to contribute to its etiology. Tumor necrosis factor-alpha (TNF-α) which plays a key role in pathogenesis of many infectious and inflammatory diseases has been found in high levels in lesional skin and sera of pemphigus patients. However, studies on association of single nucleotide polymorphism (SNP) in promoter region of TNF-α at position -308 affecting G to A transition with pemphigus has been scarce. This study was conducted to evaluate the TNF-α -308G/A SNP distribution in North Indian cohort, and to define the association between the TNF-α -308G/A SNP distribution and pemphigus, globally, by means of meta-analysis. TNF-α -308G/A SNP in pemphigus patients was investigated by cytokine genotyping using genomic DNA by PCR with sequence-specific primers. Meta-analysis of the data, including four previously published studies from other populations, was performed to generate a meaningful relationship. The results of our case-control study indicate non-significant differences between patients and controls in TNF-α -308G/A SNP. The meta-analysis also revealed that TNF-α -308G/A SNP is not associated with pemphigus risk in population at large; however, it may be contributing towards autoimmune phenomenon in pemphigus by being a part of its multi-factorial etiology. This study provides evidence that the TNF-α -308G/A polymorphism is not associated with overall pemphigus susceptibility. Nevertheless, further studies on specific ethnicity and pemphigus variants are necessary to validate the findings.


Asunto(s)
Alelos , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Pénfigo/genética , Polimorfismo de Nucleótido Simple , Factor de Necrosis Tumoral alfa/genética , Población Blanca/genética , Estudios de Casos y Controles , Femenino , Genotipo , Humanos , India , Masculino , Oportunidad Relativa , Pénfigo/diagnóstico , Sesgo de Publicación
6.
Immunol Res ; 64(4): 1001-12, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-26676360

RESUMEN

Risk posed by microbial superantigens in triggering or exacerbating SLE in genetically predisposed individuals, thereby altering the response to its treatment strategies, has not been studied. Using streptococcal pyrogenic exotoxin A and staphylococcal enterotoxin B as prototype superantigens, we have demonstrated that they profoundly affect the magnitude of polyclonal T cell response, particularly CD4(+) T cells and expression of CD45RA and CD45RO, and cytokine secretion in vitro in SLE patient PBMCs. Also, reduced proportions of FoxP3 expressing CD4(+)CD25(+) T cells were detected in SLE as compared to healthy control PBMCs. Furthermore, polymorphism in IL-10 and TGF-ß showed significant association with SLE in our study population. These results indicate that accumulation of superantigen-reactive T cells and cytokine polymorphism may cause disease exacerbation, relapse, or therapeutic resistance in SLE patients. Attempts to contain colonizing and/or superantigen-producing microbial agents in SLE patients in addition to careful monitoring of their therapy may be worthwhile in decreasing disease severity or preventing frequent relapses. The study suggests that superantigen interference in conjunction with cytokine polymorphism may play a role in immune dysregulation, thereby contributing to autoimmunity in SLE. Therefore, changes in T cell phenotypes and cytokine secretion might be good indicators of therapeutic efficacy in these patients.


Asunto(s)
Proteínas Bacterianas/inmunología , Toxinas Bacterianas/inmunología , Linfocitos T CD4-Positivos/inmunología , Exotoxinas/inmunología , Interleucina-10/metabolismo , Lupus Eritematoso Sistémico/inmunología , Proteínas de la Membrana/inmunología , Linfocitos T Reguladores/inmunología , Factor de Crecimiento Transformador beta/metabolismo , Adulto , Anticuerpos Antinucleares/sangre , Células Cultivadas , Progresión de la Enfermedad , Femenino , Factores de Transcripción Forkhead/metabolismo , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Interleucina-10/genética , Lupus Eritematoso Sistémico/tratamiento farmacológico , Activación de Linfocitos , Masculino , Polimorfismo Genético , Factor de Crecimiento Transformador beta/genética , Adulto Joven
7.
FEMS Microbiol Lett ; 362(8): fnv039, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25761751

RESUMEN

Trichophyton rubrum is one of the major causative agents of dermatophytosis in humans worldwide. We report the draft genome sequence of T. rubrum var. raubitschekii from Delhi, India, isolated from a patient presenting symptoms of onychomycosis. The total estimated genome size of the clinical isolate is 25.2 MB containing 8265 predicted protein-coding sequences, 91 tRNA and 15 rRNA genes. Sequence analysis of the secreted subtilases, one of the major virulence factors in dermatophytes, clusters them into three subfamilies with distinct sequence features. The genome sequence is a step in understanding diversity of dermatophytes worldwide and will aid in identification of virulence factors and dissecting mechanisms of pathogenesis among them.


Asunto(s)
Genoma Fúngico , Onicomicosis/microbiología , Trichophyton/genética , Arthrodermataceae/genética , Secuencia de Bases , Humanos , India , Datos de Secuencia Molecular , Análisis de Secuencia de ADN
8.
Indian J Dermatol ; 57(3): 175-80, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22707766

RESUMEN

BACKGROUND: There is great disagreement regarding which effector T-cells are responsible for the pathogenesis of systemic sclerosis. Further, the possible role of superantigens in modulating the T-cell phenotype responsible for the immunopathogenesis of this disease and the response of these patients to common recall antigens have not been adequately determined. AIMS: To investigate the T-cell subsets and activation markers in peripheral blood mononuclear cells of systemic sclerosis patients before and after stimulation with different bacterial superantigens and common recall antigens to better understand the immunopathogenesis of this disease. MATERIALS AND METHODS: T-cells (CD3(+)) from 20 systemic sclerosis patients and 17 age-matched healthy controls were studied using flow cytometry for the expression of CD4, CD8, CD45RA, and CD45RO at baseline and upon stimulation with different superantigens and recall antigens. Patients were also tested for skin delayed hypersensitivity to common recall antigens. RESULTS: The proportions of CD45RA(+) (naive) and CD45RO(+) (memory) CD4(+) T-cells were found to be significantly higher in patients than in controls upon stimulation with bacterial superantigens. However, T-cells from these patients responded weakly to recall antigen stimulation, indicating a loss of specific memory cells. This was further supported by the skin delayed hypersensitivity test in which 16 patients were found to be anergic. CONCLUSIONS: Our findings suggest that both naïve (CD45RA(+)) and memory (CD45RO(+)) CD4(+) superantigen-reactive T-cells are effector T-cells that may modulate the pathogenic autoantibody response in systemic sclerosis. Accumulation of these cells in these patients may result in increased risk of relapses and resistance to therapy.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...