Linfócitos T auxiliares foliculares e subpopulações de linfócitos B em pacientes com mucopolissacaridoses
Data
2024-10-21
Autores
Gonzalez, Isabela Garrido da SIlva 
Orientadores
Pinto, Maria Isabel Moraes
Tipo
Tese de doutorado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Introdução: a mucopolissacaridose é uma doença lisossômica decorrente da deficiência de enzimas necessárias para o metabolismo de glicosaminoglicanos. Os lisossomos são organelas que desempenham funções vitais em células do sistema imunológico e, consequentemente, estão diretamente envolvidos em diferentes processos da resposta imunitária, como a autofagia, processamento e apresentação de antígenos via MHC II, além da liberação de diferentes substâncias pró-inflamatórias através da ativação de receptores Toll-like. Por conseguinte, ao se considerar o papel relevante dos lisossomos em vias da resposta imunológica, torna-se plausível que pacientes com mucopolissacaridose possam apresentar comprometimento imunológico, tendo em vista que manifestações clínicas respiratórias são comuns em todos os tipos de MPS. Objetivo: avaliar as características imunofenotípicas dos linfócitos T auxiliares foliculares e das subpopulações de linfócitos B em pacientes com mucopolissacaridose. Casuística e métodos: este é um estudo transversal realizado em um centro de referência para pacientes com doenças genéticas, em São Paulo. Dezenove pacientes diagnosticados com diferentes tipos de mucopolissacaridose e sem infecção ativa tiveram amostras de sangue coletadas em 2019. Dezoito indivíduos saudáveis pareados pela idade tiveram amostras de sangue coletadas no mesmo ano. Através da análise por citometria de fluxo, as seguintes células foram comparadas entre os pacientes e grupo controle: células T CD3+, T CD4+, B e NK, bem como células T auxiliares foliculares circulantes e suas subpopulações. A expressão dos marcadores PD-1 e ICOS e de CXCR5, CCR6 e CXCR3 nas células T auxiliares foliculares circulantes foi também avaliada. Ademais, nove subpopulações de células B foram analisadas. Resultados: o número absoluto de células T CD3+, T CD4+, B e NK foi similar entre pacientes com mucopolissacaridose e controles. Entretanto, foi evidenciada menor proporção de células T auxiliares foliculares circulantes nos pacientes com mucopolissacaridose quando comparados aos controles saudáveis (4,34% vs 6,0%, p = 0,011). Do mesmo modo, a intensidade de fluorescência média de CXCR5+ está reduzida nos pacientes com mucopolissacaridose em comparação aos controles (mediana: 781 vs 998; p: 0,004). Por outro lado, as proporções de subpopulações de linfócitos T auxiliares foliculares circulantes, Tfh1, Tfh2 e Tfh17 em pacientes com mucopolissacaridose foram semelhantes àquelas observadas nos controles. Não houve diferença na expressão de PD-1 e ICOS entre pacientes e controles. No que concerne aos linfócitos B, as proporções de células B transicionais, células B CD21low e células B naive maduras foram similares entre pacientes e controles. Quando analisamos as células B de memória, os pacientes apresentaram maior proporção de células B de memória IgG típica quando comparados ao grupo controle (34,2% vs 21,8%, p=0,0218). A proporção de células B de memória sem troca de isotipo, células B de memória com troca de isotipo, células B de memória IgM-only, células B de memória IgG atípicas e plasmablastos foram semelhantes entre pacientes e grupo controle. Conclusões: a proporção de linfócitos T auxiliares foliculares circulantes, subpopulação envolvida na resposta imunológica do centro germinativo, está reduzida em pacientes com mucopolissacaridose, sugerindo que doenças lisossômicas têm um impacto proeminente não apenas na resposta inata, mas também na resposta adaptativa, com consequente predisposição a infecções respiratórias de repetição, característica clínica proeminente desses pacientes. Estudos funcionais futuros podem fornecer maior compreensão das causas e consequências dos nossos achados, fornecendo novas indicações de como tratar e manejar a mucopolissacaridose.
Introduction: Mucopolysaccharidosis diseases are lysosomal storage disorders arising from deficiencies in enzymes required for the catabolism of glycosaminoglycans. Mucopolysaccharidosis are likely to encompass immune involvement, as lysosomes represent vital components of immune cell processes, including autophagy, antigen processing and presentation on MHC II, along with release of different inflammatory substances through the activation of Toll-like receptors. Therefore, when considering the relevant role of lysosomes in immune response pathways, it becomes plausible that patients with mucopolysaccharidosis may present immunological impairment, given that clinical respiratory manifestations are common in all types of MPS. The aim of this study is to evaluate the immunophenotypic characteristics of follicular helper T-cells and B-cells subsets in mucopolysaccharidosis patients. Material and methods: This is a transversal study conducted at a Brazilian referral Centre for patients with genetic diseases, in São Paulo. Nineteen patients diagnosed with mucopolysaccharidosis and without active infection had their samples collected in 2019. Eighteen healthy age matched control subjects had their samples collected in the same year. Through Flow Cytometer analysis we compared the following cells subsets between patients and controls: CD3+T, CD4+T, B and NK cell, as well as circulating T follicular helper cells and their subsets. The expression of PD1, ICOS, CXCR5, CCR6 and CXCR3 in the total number of circulating T follicular helper cells was also evaluated. Furthermore, nine B-cell subsets were analysed. Results: The absolute number of T CD3+, T CD4+, B and NK cells was similar between mucopolysaccharidosis patients and controls. Nevertheless, mucopolysaccharidosis patients had lower percentages of circulating T follicular helper cells than controls (4.34% vs 6.0%, p = 0,011). Similarly, the expression of CXCR5 in total circulating T follicular helper cells was decreased in patients when compared with health controls (median: 781 vs 998; p = 0,004). On the other hand, the percentages of circulating T follicular helper cells subsets, Tfh1, Tfh2 and Tfh17-cells in mucopolysaccharidosis patients were similar to those observed in controls. No difference in PD-1 or ICOS expression were observed between patients and controls. Regarding B cells, the proportions of transitional, CD21-low and naïve-mature B-cells were similar between patients and controls. When we analysed memory B cells subset, patients showed a higher proportion in IgG memory B-cells (34.2% vs 21.8%, p = 0,033). The proportion of natural effector B-cells, IgM only B-cells, memory with switch B-cells, atypical IgG memory B-cells, and plasmablasts were similar between patients and control subjects. Conclusions: The proportion of circulating T follicular cells is reduced in mucopolysaccharidosis patients, the cell subset responsible for the germinal center immune response, suggesting that lysosomal diseases are likely to have a prominent impact not only on innate, but also on adaptive immunity, with consequent predisposition to recurrent respiratory infections, a prominent clinical characteristic of these patients. Future functional studies may provide a better understanding of the causes and consequences of our findings, offering new insights on how to treat mucopolysaccharidosis.
Introduction: Mucopolysaccharidosis diseases are lysosomal storage disorders arising from deficiencies in enzymes required for the catabolism of glycosaminoglycans. Mucopolysaccharidosis are likely to encompass immune involvement, as lysosomes represent vital components of immune cell processes, including autophagy, antigen processing and presentation on MHC II, along with release of different inflammatory substances through the activation of Toll-like receptors. Therefore, when considering the relevant role of lysosomes in immune response pathways, it becomes plausible that patients with mucopolysaccharidosis may present immunological impairment, given that clinical respiratory manifestations are common in all types of MPS. The aim of this study is to evaluate the immunophenotypic characteristics of follicular helper T-cells and B-cells subsets in mucopolysaccharidosis patients. Material and methods: This is a transversal study conducted at a Brazilian referral Centre for patients with genetic diseases, in São Paulo. Nineteen patients diagnosed with mucopolysaccharidosis and without active infection had their samples collected in 2019. Eighteen healthy age matched control subjects had their samples collected in the same year. Through Flow Cytometer analysis we compared the following cells subsets between patients and controls: CD3+T, CD4+T, B and NK cell, as well as circulating T follicular helper cells and their subsets. The expression of PD1, ICOS, CXCR5, CCR6 and CXCR3 in the total number of circulating T follicular helper cells was also evaluated. Furthermore, nine B-cell subsets were analysed. Results: The absolute number of T CD3+, T CD4+, B and NK cells was similar between mucopolysaccharidosis patients and controls. Nevertheless, mucopolysaccharidosis patients had lower percentages of circulating T follicular helper cells than controls (4.34% vs 6.0%, p = 0,011). Similarly, the expression of CXCR5 in total circulating T follicular helper cells was decreased in patients when compared with health controls (median: 781 vs 998; p = 0,004). On the other hand, the percentages of circulating T follicular helper cells subsets, Tfh1, Tfh2 and Tfh17-cells in mucopolysaccharidosis patients were similar to those observed in controls. No difference in PD-1 or ICOS expression were observed between patients and controls. Regarding B cells, the proportions of transitional, CD21-low and naïve-mature B-cells were similar between patients and controls. When we analysed memory B cells subset, patients showed a higher proportion in IgG memory B-cells (34.2% vs 21.8%, p = 0,033). The proportion of natural effector B-cells, IgM only B-cells, memory with switch B-cells, atypical IgG memory B-cells, and plasmablasts were similar between patients and control subjects. Conclusions: The proportion of circulating T follicular cells is reduced in mucopolysaccharidosis patients, the cell subset responsible for the germinal center immune response, suggesting that lysosomal diseases are likely to have a prominent impact not only on innate, but also on adaptive immunity, with consequent predisposition to recurrent respiratory infections, a prominent clinical characteristic of these patients. Future functional studies may provide a better understanding of the causes and consequences of our findings, offering new insights on how to treat mucopolysaccharidosis.
Descrição
Citação
GONZALEZ, Isabela Garrido da SIlva. Linfócitos T auxiliares foliculares e subpopulações de linfócitos B em pacientes com mucopolissacaridoses. 2024. 135 f. Tese (Doutorado em Pediatria e Ciências Aplicadas à Pediatria) - Escola Paulista de Medicina, Universidade Federal de São Paulço (UNIFESP). São Paulo, 2024.