Association of NLRP3 Inflammasome and Autophagy Pathways With Cytokine Storm and Disease Severity in Dengue Patients

Dengue infects approximately 350 million people globally, with 25,000 casualties each year. Dengue Infection clinically ranges from mild febrile illness to life-threatening severe dengue with vascular leakage. While dysregulated immune responses are known to drive disease progression, the role of NLRP3 inflammasome activation and Autophagy in dengue pathogenesis remains unclear. Among 1,897 suspected cases, 318 confirmed dengue patients were enrolled and classified as dengue fever with or without warning signs (DF ± WS, n = 229) or severe dengue (SD, n = 89), alongside 50 healthy controls. PBMCs were analyzed for inflammasome and Autophagy gene expression by qRT-PCR, cytokine levels (IL-1β, IL-18) by ELISA, and protein expression (Beclin1, LC3B) by Western blot. PBMCs were stimulated with dengue peptide pools, subjected to NLRP3 siRNA silencing, and treated with rapamycin (Autophagy Inducer) or 3-methyladenine (Autophagy inhibitor) to assess pathway modulation. GraphPad Prism and ImageJ software were used for statistical and protein densitometry analysis, respectively. NLRP3, RIG1, and associated inflammasome genes, along with Beclin1 and LC3B, were significantly upregulated in dengue patients, with the highest expression in severe cases. Elevated IL-1β and IL-18 levels in patient sera and stimulated PBMCs correlated positively with NLRP3 expression. NLRP3 silencing reduced pro-inflammatory cytokine secretion. Rapamycin enhanced Beclin-1/LC3B expression and cytokine production, while 3-methyladenine suppressed these effects. The findings suggest a synergistic role of inflammasome activation and Autophagy in promoting cytokine storm and disease severity. Upregulated NLRP3 inflammasome and Beclin1/LC3B Autophagy pathways in the host may potentially drive hyperinflammatory responses (elevated IL-1β and IL-18 levels), contributing to vascular leakage in severe dengue. However, this mechanism may be regulated in DF ± WS, resulting in their recovery and may offer therapeutic opportunities to mitigate disease severity.

LC3B; NLRP3 inflammasome; autophagy; beclin1; cytokine storm; dengue virus; disease severity.