Anti-cytokines as a Strategy in Alpha-1 Antitrypsin Deficiency

For many years, the lung disease associated with alpha-1 antitrypsin (AAT) deficiency (AATD) was perceived as being secondary to an imbalance between this serine protease inhibitor and the target protease, neutrophil elastase (NE). More recently, a greater understanding of the pathways leading to lung inflammation has shed light on new potential attributes and presented AATD as an inflammatory condition in which proteases and neutrophils still play a major role, but in which pro-inflammatory cytokines, either induced by the actions of NE or by other pro-inflammatory processes normally modulated by AAT, are involved. In this review, we will look at the various cytokines centrally involved in AATD lung disease, and how a greater understanding of their contribution may help development of targeted therapies.

IRF5-mediated immune responses and its implications in immunological disorders

Transcription factors are gene regulators that activate or repress target genes. One family of the transcription factors that have been extensively studied for their crucial role in regulating gene network in the immune system is the interferon regulatory factors (IRFs). IRFs possess a novel turn-helix turn motif that recognizes a specific DNA consensus found in the promoters of many genes that are involved in immune responses. IRF5, a member of IRFs has recently gained much attention for its role in regulating inflammatory responses and autoimmune diseases. Here, we discuss the role of IRF5 in regulating immune cells functions and how the dysregulation of IRF5 contributes to the pathogenesis of immune disorders. We also review the latest findings of potential IRF5 inhibitors that modulate IRF5 activity in the effort of developing therapeutic approaches for treating inflammatory disorders.

Porcine reproductive and respiratory syndrome virus (PRRSV) induces IL-12p40 production through JNK-AP-1 and NF-κB signaling pathways

Porcine reproductive and respiratory syndrome virus (PRRSV) mainly infects monocyte/macrophage cells and modulates cytokine production to regulate host immune response. IL-12p40 is the basic subunit of IL-12, a heterodimeric cytokine, which plays key roles in the cell-mediated immune response. In the present study, we demonstrated that PRRSV infection induced IL-12p40 production in vitro and in vivo. Subsequently, we showed that inhibitors of p38 MAPK, JNK, and NF-κB dramatically reduced PRRSV-induced IL-12p40 expression. To further characterize the molecular mechanism of IL-12p40 production induced by PRRSV infection, we cloned and analyzed the porcine IL-12p40 promoter, in which AP-1 and NF-κB motifs were found. In addition, both JNK-AP-1 and NF-κB signaling pathways were activated by PRRSV infection. Taken together, these data indicate that PRRSV induces IL-12p40 expression through the JNK-AP-1 and NF-κB signaling pathways. Our findings might facilitate our understanding of the molecular mechanisms of IL-12 production induced by PRRSV infection.