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Updated: Dec 17, 2025
Neutrophil Isolation and Analysis to Determine their Role in Lymphoma Cell Sensitivity to Therapeutic Agents
Published on: March 25, 2016
Plasticity of High-Density Neutrophils in Multiple Myeloma is Associated with Increased Autophagy Via STAT3
Fabrizio Puglisi1,2, Nunziatina Laura Parrinello2,3, Cesarina Giallongo2
1Department of Surgery and Medical Specialties, University of Catania, 95123 Catania, Italy.
Abstract:
In both monoclonal gammopathy of uncertain significance (MGUS) and multiple myeloma (MM) patients, immune functions are variably impaired, and there is a high risk of bacterial infections. Neutrophils are the most abundant circulating leukocytes and constitute the first line of host defense. Since little is known about the contribution of autophagy in the neutrophil function of MGUS and MM patients, we investigated the basal autophagy flux in freshly sorted neutrophils of patients and tested the plastic response of healthy neutrophils to soluble factors of MM. In freshly sorted high-density neutrophils obtained from patients with MGUS and MM or healthy subjects, we found a progressive autophagy trigger associated with soluble factors circulating in both peripheral blood and bone marrow, associated with increased IFNγ and pSTAT3S727. In normal high-density neutrophils, the formation of acidic vesicular organelles, a morphological characteristic of autophagy, could be induced after exposure for three hours with myeloma conditioned media or MM sera, an effect associated with increased phosphorylation of STAT3-pS727 and reverted by treatment with pan-JAK2 inhibitor ruxolitinib. Taken together, our data suggest that soluble factors in MM can trigger contemporary JAK2 signaling and autophagy in neutrophils, targetable with ruxolitinib.
Insights
Soluble factors in multiple myeloma (MM) trigger neutrophil autophagy and JAK2 signaling. This process, involving increased IFNγ and pSTAT3S727, can be targeted by ruxolitinib, offering potential therapeutic strategies for immune dysfunction in MM patients.
Area of Science:
- Immunology
- Cell Biology
- Hematology
Background:
- Patients with monoclonal gammopathy of uncertain significance (MGUS) and multiple myeloma (MM) exhibit impaired immune functions and are at high risk for bacterial infections.
- Neutrophils, critical for host defense, have poorly understood autophagy mechanisms in MGUS and MM.
- Autophagy plays a role in neutrophil function, but its specific contribution in MGUS and MM patients remains largely unexplored.
Purpose of the Study:
- To investigate basal autophagy flux in neutrophils from MGUS and MM patients.
- To examine the response of healthy neutrophils to soluble factors found in MM.
- To elucidate the signaling pathways involved in neutrophil autophagy modulation by MM-associated factors.
Main Methods:
- Analysis of basal autophagy flux in freshly sorted high-density neutrophils from MGUS, MM patients, and healthy subjects.
- Exposure of healthy neutrophils to myeloma-conditioned media and MM sera to assess functional responses.
- Measurement of autophagy markers, including acidic vesicular organelles formation.
- Assessment of signaling pathway activation, specifically IFNγ and STAT3 phosphorylation (pSTAT3S727).
- Evaluation of the effect of JAK2 inhibitor ruxolitinib on MM-induced neutrophil autophagy.
Main Results:
- A progressive autophagy trigger was observed in neutrophils from MGUS and MM patients, linked to circulating soluble factors.
- Exposure to MM-conditioned media or sera induced autophagy in healthy neutrophils, characterized by increased acidic vesicular organelles.
- This induction was associated with elevated STAT3-pS727 phosphorylation.
- Treatment with the pan-JAK2 inhibitor ruxolitinib reverted the MM-induced autophagy.
Conclusions:
- Soluble factors present in multiple myeloma can activate JAK2 signaling and induce autophagy in neutrophils.
- The observed JAK2-STAT3 signaling pathway is implicated in the modulation of neutrophil autophagy by MM-associated factors.
- Ruxolitinib demonstrates potential as a therapeutic agent to target this pathway and restore neutrophil function in MM.
