Immunopathogenesis of Systemic Lupus Erythematosus: Interplay of Innate and Adaptive Immunity, Microbiome Dysbiosis, and Emerging Therapeutic Targets

Systemic lupus erythematosus is a multifactorial autoimmune disease characterized by the dysregulation of both innate and adaptive immunity, resulting in chronic inflammation, autoantibody production, and multi-organ damage. Innate immune dysfunction involves macrophages, neutrophils, plasmacytoid dendritic cells, natural killer cells, and the complement system, which collectively amplify autoimmunity through defective clearance of apoptotic cells, overproduction of pro-inflammatory cytokines, and abnormal type I interferon signaling. Adaptive immune abnormalities, including skewed T-cell subsets, impaired regulatory T and B cells, and autoreactive B-cell hyperactivity, further perpetuate pathogenic autoantibody generation. Gut microbiota dysbiosis contributes to SLE pathogenesis via Th17 activation, loss of mucosal tolerance, and molecular mimicry mechanisms. This review synthesizes current knowledge on the immunopathogenesis of SLE, emphasizing the interplay between innate and adaptive immunity and integrating evidence from both human and experimental murine models to provide a comprehensive understanding of disease mechanisms.