RESUMO

INTRODUCTION: In ST-elevation myocardial infarction (STEMI), inflammation is pivotal, with early senescent CD4+CD28null cells implicated in its pathogenesis. However, the functional phenotype of these cells within the coronary circulation remains unclear. METHODS: We examined CD4+ cell subpopulations in blood samples from the coronary sinus and vena cava of 24 STEMI patients and the cephalic vein of seven healthy controls. RESULTS: Our findings revealed reduced CD4+ cell counts in STEMI patients compared to controls (1,998, 1,275-3,268 vs. 4,278, 3,595-4,449), alongside an increased proportion of CD4+ cells lacking CD28 expression (20.1 vs. 6.1%). These CD4+CD28null cells in STEMI predominantly exhibited a Th1 phenotype (47.8% vs. 6.6%). Intriguingly, no significant differences were detected in CD4+CD28null cells between coronary sinus and vena cava, and cytokine levels in these compartments remained similar. CONCLUSION: CD4+CD28null cells are increased in STEMI, mainly polarized toward a Th1 phenotype, and distributed equally between the different vascular beds.

Assuntos

Antígenos CD28 , Linfócitos T CD4-Positivos , Circulação Coronária , Citocinas , Fenótipo , Infarto do Miocárdio com Supradesnível do Segmento ST , Células Th1 , Humanos , Infarto do Miocárdio com Supradesnível do Segmento ST/sangue , Infarto do Miocárdio com Supradesnível do Segmento ST/imunologia , Infarto do Miocárdio com Supradesnível do Segmento ST/patologia , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Estudos de Casos e Controles , Antígenos CD28/metabolismo , Células Th1/imunologia , Citocinas/sangue , Citocinas/metabolismo , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Senescência Celular , Seio Coronário , Mediadores da Inflamação/sangue , Mediadores da Inflamação/metabolismo , Contagem de Linfócito CD4 , Imunofenotipagem

RESUMO

Innate immune system activation is crucial in the inflammatory response, but uncontrolled activation can lead to autoimmune diseases. Cellular exhaustion and senescence are two processes that contribute to innate immune tolerance breakdown. Exhausted immune cells are unable to respond adequately to specific antigens or stimuli, while senescent cells have impaired DNA replication and metabolic changes. These processes can impair immune system function and disrupt homeostasis, leading to the emergence of autoimmunity. However, the influence of innate immune exhaustion and senescence on autoimmune disorders is not well understood. This review aims to describe the current findings on the role of innate immune exhaustion and senescence in autoimmunity, focusing on the cellular and molecular changes involved in each process. Specifically, the article explores the markers and pathways associated with immune exhaustion, such as PD-1 and TIM-3, and senescence, including Β-galactosidase (β-GAL), lamin B1, and p16ink4a, and their impact on autoimmune diseases, namely type 1 diabetes, rheumatoid arthritis, systemic lupus erythematosus, and immune-mediated myopathies. Understanding the mechanisms underlying innate immune exhaustion and senescence in autoimmunity may provide insights for the development of novel therapeutic strategies.