NLRP3 inflammasome activation and symptom burden in KRAS-mutated CMML patients is reverted by IL-1 blocking therapy

Area of Science:

• Hematology
• Immunology
• Molecular Biology

Background:

• Chronic myelomonocytic leukemia (CMML) often involves RAS gene mutations, correlating with poorer patient outcomes.
• RAS mutations lead to constitutively active RAS-GTP, promoting myeloid cell proliferation and survival.
• RAS activation can trigger the NLRP3 inflammasome, leading to caspase-1 activation and Interleukin-1 beta (IL-1β) release.

Purpose of the Study:

• To investigate NLRP3 inflammasome activation in CMML patients with RAS mutations.
• To assess the therapeutic potential of targeting the IL-1 pathway in a KRAS-mutated CMML patient.

Main Methods:

• Analysis of NLRP3 inflammasome activation markers (ASC oligomerization, IL-1β release) in monocytes from CMML patients.
• Characterization of the inflammatory cytokine signature in these patients.
• Clinical treatment of a CMML patient with a KRAS^G12D mutation using anakinra, an IL-1 receptor blocker.

Main Results:

• Constitutive NLRP3 inflammasome activation was observed in monocytes of CMML patients with KRAS mutations, indicated by ASC oligomerization and IL-1β release.
• A distinct inflammatory cytokine profile was identified in these patients.
• Anakinra treatment in a patient with KRAS^G12D mutation successfully inhibited NLRP3 inflammasome activation, reduced monocyte counts, and improved clinical status, facilitating a stem cell transplant.

Conclusions:

• RAS-mutated CMML exhibits basal NLRP3 inflammasome activation.
• Targeting the NLRP3 inflammasome and IL-1 signaling represents a promising therapeutic strategy for RAS-mutated CMML.