Papel del IFN-λ en la patogénesis del Lupus eritematoso sistémico: mecanismos Biomoleculares

Introducción: El lupus eritematoso sistémico (LES) es una enfermedad autoinmune que causa inflamación sistémica y alteraciones en la tolerancia inmunológica. La activación de los genes inducibles por interferón (IFN), contribuye en más del 50% de su patogenia. Objetivo: relacionar el papel del IFN-λ en la patogenia del LES. Materiales y Métodos: Búsqueda sistémica en base de datos; a través de las palabras claves del MeSH and DeCS. Fue incluido adicionalmente la palabra "Interferón Lambda". Resultados: Se encontró que la producción aberrante de interferón tipo I contribuye a la desregulación de IFN-λ, producido principalmente por células dendríticas plasmocitoides. Este proceso conduce a la estimulación inmunológica por autoanticuerpos y a un aumento de IFNλR-1 en células B, potenciando la generación de anticuerpos. IFN-λ3 se asocia particularmente con nefritis lúpica, y el IFN-λ en general aumenta la expresión de MHC-I, intensificando la respuesta de células T CD8+ y posiblemente afectando la tolerancia central y la regulación en el timo. Conclusión: Se destaca que el IFN-λ favorece la activación inmune, formación de inmunocomplejos, inflamación crónica y producción de autoanticuerpos, vinculándose niveles altos de IFN-λ3 con mayor actividad de la enfermedad.

Introduction: Systemic lupus erythematosus (SLE) is an autoimmune disease that causes systemic inflammation and alterations in immunological tolerance. The activation of interferon (IFN)-inducible genes contributes to more than 50% of its pathogenesis. Objective: to review the role of IFN-λ in the pathogenesis of SLE. Materials and Methods: Systemic search in database; through the MeSH and DeCS keywords. The word "Lambda Interferon" was additionally included. Results: Aberrant production of type I interferon was found to contribute to the deregulation of IFN-λ, produced mainly by plasmacytoid dendritic cells. This process leads to immunological stimulation by autoantibodies and an increase in IFNλR-1 in B cells, enhancing the generation of antibodies. IFN-λ3 is particularly associated with lupus nephritis, and IFN-λ generally increases MHC-I expression, enhancing the CD8+ T cell response and possibly affecting central tolerance and regulation in the thymus. Conclusion: It is highlighted that IFN-λ favors immune activation, formation of immune complexes, chronic inflammation and production of autoantibodies, linking high levels of IFN-λ3 with greater disease activity.

Pathways of IFN-alpha Activation in Patients with Cervical Intraepithelial Neoplasia (CIN) / Vias de ativação de IFN-alfa em pacientes com Neoplasia Intraepitelial Cervical (NIC)

Abstract Objective The aim of the present study was to compare the local and systemic expression of the factors linked to the interferon alpha (IFN-α) activation pathway in different degrees of cervical intraepithelial neoplasia (CIN) and cervical cancer. Methods A total of 128 patients with CIN I, CIN II, CIN III and cervical cancer was evaluated. The real-time polymerase chain reaction (RT-PCR) technique was used to evaluate the gene expression of IFNR1, IFNR2, IFN-α, oligoadenylate synthase (2'5′OAS), cytokine signal suppressor 1 (SOCS) 1, SOCS3, signal transducer and transcription activator 1 (STAT1), and IRF9 from 128 biopsies. A total of 46 out of 128 samples were evaluated by flow cytometry for IFNAR1, IFNAR2, STAT1, IRF7 and IFN-α in peripheral blood cells. Results Patients with CIN II and III (63 samples) had a low local expression of IFNR1, but not IFNR2. Patients with some degree of injury showed high expression of SOCS1 and SOCS3. Systemically, patients with CIN II and III (20 samples) had a significant increase in IFNR1, IFNR2, STAT1, IRF7, and IFN-α in helper, cytotoxic T lymphocytes, and in monocytes. Conclusion Patients with high-grade lesions have increased systemic expression of IFN-α and its activation pathways in helper and cytotoxic T lymphocytes, as well as in monocytes due to an exacerbation of the immune response in these patients. This phenomenon is not accompanied by resolution of the lesion due to a defect in the IFN-α activation pathway that revealed by low local IFNAR1 expression and high local expression of SOCS1 and SOCS3.

Resumo Objetivo O objetivo do presente estudo foi comparar a expressão local e sistêmica dos fatores ligados à via de ativação do interferon alfa (IFN-α) em diferentes graus de neoplasia intraepitelial cervical (NIC) e câncer cervical (CA) Métodos Foram avaliados 128 pacientes com NIC I, NIC II, NIC III e CA. A técnica de reação de cadeia de polimerase em tempo real (RT-PCR, na sigla em inglês) foi realizada para avaliar a expressão gênica do receptor de interferon (IFNR) 1, IFNR2, IFN-α, 2′-5′- oligoadenilato sintetase (2′5′OAS), supressor de sinalização de citocina (SOCS)1, SOCS3, transdutor de sinal e ativador de transcrição 1 (STAT1) e fator regulador de interferon 9 (IRF9) das 128 biópsias. Das 128 amostras, 46 foram avaliadas por citometria de fluxo para IFNAR1, IFNAR2, STAT1, IRF7 e IFN-α em células de sangue periférico. Resultados Pacientes com NIC II e III (63 amostras) tiveram baixa expressão local de IFNR1 mas não de IFNR2. Pacientes com algum grau de lesão apresentaram alta expressão de SOCS1 e SOCS3. Sistemicamente, os pacientes com NIC II e III (20 amostras) tiveram um aumento significativo de IFNR1, IFNR2, STAT1, IRF7 e IFN-α em linfócitos T auxiliares, citotóxicos e monócitos. Conclusão Pacientes com lesões de alto grau apresentam expressão sistêmica aumentada de IFN-α e suas vias de ativação em linfócitos T auxiliares e citotóxicos, bem como em monócitos, devido à exacerbação da resposta imune nesses pacientes. Este fenômeno não é acompanhado pela resolução da lesão devido a um defeito na via de ativação do IFN-α que é revelado pela baixa expressão local de IFNR1 e alta expressão local de SOCS1 e SOCS3.

Partial Interferon-gamma Receptor Deficiency in Patients with Disseminated Tuberculosis / 결핵및호흡기질환

BACKGROUND: Interferon-gamma (IFN-gamma) is essential in the immune response to mycobacterial infections, and a complete or partial deficiency in the IFN-gamma receptor 1 (IFNgammaR1) or the IFN-gamma receptor 2 (IFNgammaR2) have been reported to confer susceptibility to a disseminated infection with nontuberculous mycobacteria. However, similar mutations in the IFN-gamma receptor have not been specifically examined in the patients with clinical tuberculosis. METHODS: This study searched for mutations in the IFN-gamma receptor gene that resulted in a partial IFN-gamma receptor deficiency in six patients with disseminated tuberculosis. The previously identified IFNgammaR1 and IFNgammaR2 coding regions were sequenced after amplification. RESULTS: There was no partial IFNgammaR1 deficiency including a homozygous recessive missense mutation causing an amino-acid substitution in the extracellular domain of the receptor (I87T) and a hotspot for small deletions (818delT, 818del4, 818insA) found in any of the patients. In addition, a partial IFNgammaR2 deficiency of the homozygous missense mutation (R114C) was not found in any of the patients. CONCLUSION: Genetic defects causing a partial IFN-gamma receptor deficiency were not identified in our patients with disseminated tuberculosis.