IBRUTINIB STIMULATES IL-10 SECRETION BY NLCS, MEDIATING A PARTIAL PROTECTION OF CLL CELLS FROM APOPTOSIS
(Abstract release date: 05/19/16)
EHA Library. Fiorcari S. 06/09/16; 132569; E1020
Dr. Stefania Fiorcari
Contributions
Contributions
Abstract
Abstract: E1020
Type: Eposter Presentation
Background
In lymphatic tissues, CLL cells establish intimate contact with accessory cells, such as nurse-like cells (NLCs). NLCs have a pivotal role in CLL clone maintenance and support CLL cell survival, proliferation and protection from drug-induced apoptosis. Ibrutinib is a potent inhibitor of Btk kinase, able to counteract the pro-survival effects in CLL cells provided by microenvironment. A peculiar effect of ibrutinib includes reduced retention and homing of CLL cells to tissue compartments and a mobilization from microenvironmental niches into the peripheral blood.
Aims
Here, we investigated the biological effects and mechanism mediated by ibrutinib on CLL- NLCs crosstalk.
Methods
CLL-PBMCs were cultured in complete medium for 12 days and then treated with 1µM ibrutinib. NLC phenotype was analyzed upon ibrutinib exposure. IL-10 production was tested by real time PCR and CSA in NLCs. CD19+ CLL cells viability and analysis of signaling pathways in presence of IL-10 stimulation were evaluated after treatment with ibrutinib.
Results
First, we found that CLL cells cultured without NLCs are more sensitive to ibrutinib-induced apoptosis if compared to CLL cultured with NLCs. Indeed ibrutinib does not completely hamper the protective effect mediated by NLCs on leukemic cells when both CLL and NLCs are exposed to the drug (p<0.05 at 24h, 48h and 72h) . Among the plethora of factors potentially involved in CLL desensitization to ibrutinib effect, NLCs were characterized by a strong up-regulation of IL10 and NAMPT known to be involved in CLL protection from apoptosis (p<0.05). We focused our attention on IL-10 and we demonstrated that treatment with ibrutinib for 24h improves NLCs secretion of IL-10. CD19+ CLL cells stimulated with IL-10 in a dose escalation experiment (from 0.1 ng/ml to 100 ng/ml) show good protection from apoptosis at different doses at different time-points. We then analyzed the ability of ibrutinib to abrogate the pro-survival signal induced by IL10 stimulation (1 ng/ml) in CD19+ CLL cells after 24-48h of culture. Ibrutinib does not completely antagonize the ability of IL-10 to protect CLL cells from apoptosis and to activate pSTAT3 and pERK signaling pathways. In accordance, ibrutinib is able to potentiate the immunosuppressive and permissive profile of NLCs stimulating the expression of CD163, CD206 and the activation of pSTAT6 with a concomitant inhibition of pSTAT1.
Conclusion
The ability of ibrutinib to effectively disrupt the crosstalk between CLL cells and NLCs is still unclear. Our data demonstrate that ibrutinib may also target NLCs, potentiating their permissive features through the secretion of unwanted survival factors such as IL-10. .
Session topic: E-poster
Keyword(s): Chronic lymphocytic leukemia, Immunomodulation, Microenvironment, Signal transduction
Type: Eposter Presentation
Background
In lymphatic tissues, CLL cells establish intimate contact with accessory cells, such as nurse-like cells (NLCs). NLCs have a pivotal role in CLL clone maintenance and support CLL cell survival, proliferation and protection from drug-induced apoptosis. Ibrutinib is a potent inhibitor of Btk kinase, able to counteract the pro-survival effects in CLL cells provided by microenvironment. A peculiar effect of ibrutinib includes reduced retention and homing of CLL cells to tissue compartments and a mobilization from microenvironmental niches into the peripheral blood.
Aims
Here, we investigated the biological effects and mechanism mediated by ibrutinib on CLL- NLCs crosstalk.
Methods
CLL-PBMCs were cultured in complete medium for 12 days and then treated with 1µM ibrutinib. NLC phenotype was analyzed upon ibrutinib exposure. IL-10 production was tested by real time PCR and CSA in NLCs. CD19+ CLL cells viability and analysis of signaling pathways in presence of IL-10 stimulation were evaluated after treatment with ibrutinib.
Results
First, we found that CLL cells cultured without NLCs are more sensitive to ibrutinib-induced apoptosis if compared to CLL cultured with NLCs. Indeed ibrutinib does not completely hamper the protective effect mediated by NLCs on leukemic cells when both CLL and NLCs are exposed to the drug (p<0.05 at 24h, 48h and 72h) . Among the plethora of factors potentially involved in CLL desensitization to ibrutinib effect, NLCs were characterized by a strong up-regulation of IL10 and NAMPT known to be involved in CLL protection from apoptosis (p<0.05). We focused our attention on IL-10 and we demonstrated that treatment with ibrutinib for 24h improves NLCs secretion of IL-10. CD19+ CLL cells stimulated with IL-10 in a dose escalation experiment (from 0.1 ng/ml to 100 ng/ml) show good protection from apoptosis at different doses at different time-points. We then analyzed the ability of ibrutinib to abrogate the pro-survival signal induced by IL10 stimulation (1 ng/ml) in CD19+ CLL cells after 24-48h of culture. Ibrutinib does not completely antagonize the ability of IL-10 to protect CLL cells from apoptosis and to activate pSTAT3 and pERK signaling pathways. In accordance, ibrutinib is able to potentiate the immunosuppressive and permissive profile of NLCs stimulating the expression of CD163, CD206 and the activation of pSTAT6 with a concomitant inhibition of pSTAT1.
Conclusion
The ability of ibrutinib to effectively disrupt the crosstalk between CLL cells and NLCs is still unclear. Our data demonstrate that ibrutinib may also target NLCs, potentiating their permissive features through the secretion of unwanted survival factors such as IL-10. .
Session topic: E-poster
Keyword(s): Chronic lymphocytic leukemia, Immunomodulation, Microenvironment, Signal transduction
Abstract: E1020
Type: Eposter Presentation
Background
In lymphatic tissues, CLL cells establish intimate contact with accessory cells, such as nurse-like cells (NLCs). NLCs have a pivotal role in CLL clone maintenance and support CLL cell survival, proliferation and protection from drug-induced apoptosis. Ibrutinib is a potent inhibitor of Btk kinase, able to counteract the pro-survival effects in CLL cells provided by microenvironment. A peculiar effect of ibrutinib includes reduced retention and homing of CLL cells to tissue compartments and a mobilization from microenvironmental niches into the peripheral blood.
Aims
Here, we investigated the biological effects and mechanism mediated by ibrutinib on CLL- NLCs crosstalk.
Methods
CLL-PBMCs were cultured in complete medium for 12 days and then treated with 1µM ibrutinib. NLC phenotype was analyzed upon ibrutinib exposure. IL-10 production was tested by real time PCR and CSA in NLCs. CD19+ CLL cells viability and analysis of signaling pathways in presence of IL-10 stimulation were evaluated after treatment with ibrutinib.
Results
First, we found that CLL cells cultured without NLCs are more sensitive to ibrutinib-induced apoptosis if compared to CLL cultured with NLCs. Indeed ibrutinib does not completely hamper the protective effect mediated by NLCs on leukemic cells when both CLL and NLCs are exposed to the drug (p<0.05 at 24h, 48h and 72h) . Among the plethora of factors potentially involved in CLL desensitization to ibrutinib effect, NLCs were characterized by a strong up-regulation of IL10 and NAMPT known to be involved in CLL protection from apoptosis (p<0.05). We focused our attention on IL-10 and we demonstrated that treatment with ibrutinib for 24h improves NLCs secretion of IL-10. CD19+ CLL cells stimulated with IL-10 in a dose escalation experiment (from 0.1 ng/ml to 100 ng/ml) show good protection from apoptosis at different doses at different time-points. We then analyzed the ability of ibrutinib to abrogate the pro-survival signal induced by IL10 stimulation (1 ng/ml) in CD19+ CLL cells after 24-48h of culture. Ibrutinib does not completely antagonize the ability of IL-10 to protect CLL cells from apoptosis and to activate pSTAT3 and pERK signaling pathways. In accordance, ibrutinib is able to potentiate the immunosuppressive and permissive profile of NLCs stimulating the expression of CD163, CD206 and the activation of pSTAT6 with a concomitant inhibition of pSTAT1.
Conclusion
The ability of ibrutinib to effectively disrupt the crosstalk between CLL cells and NLCs is still unclear. Our data demonstrate that ibrutinib may also target NLCs, potentiating their permissive features through the secretion of unwanted survival factors such as IL-10. .
Session topic: E-poster
Keyword(s): Chronic lymphocytic leukemia, Immunomodulation, Microenvironment, Signal transduction
Type: Eposter Presentation
Background
In lymphatic tissues, CLL cells establish intimate contact with accessory cells, such as nurse-like cells (NLCs). NLCs have a pivotal role in CLL clone maintenance and support CLL cell survival, proliferation and protection from drug-induced apoptosis. Ibrutinib is a potent inhibitor of Btk kinase, able to counteract the pro-survival effects in CLL cells provided by microenvironment. A peculiar effect of ibrutinib includes reduced retention and homing of CLL cells to tissue compartments and a mobilization from microenvironmental niches into the peripheral blood.
Aims
Here, we investigated the biological effects and mechanism mediated by ibrutinib on CLL- NLCs crosstalk.
Methods
CLL-PBMCs were cultured in complete medium for 12 days and then treated with 1µM ibrutinib. NLC phenotype was analyzed upon ibrutinib exposure. IL-10 production was tested by real time PCR and CSA in NLCs. CD19+ CLL cells viability and analysis of signaling pathways in presence of IL-10 stimulation were evaluated after treatment with ibrutinib.
Results
First, we found that CLL cells cultured without NLCs are more sensitive to ibrutinib-induced apoptosis if compared to CLL cultured with NLCs. Indeed ibrutinib does not completely hamper the protective effect mediated by NLCs on leukemic cells when both CLL and NLCs are exposed to the drug (p<0.05 at 24h, 48h and 72h) . Among the plethora of factors potentially involved in CLL desensitization to ibrutinib effect, NLCs were characterized by a strong up-regulation of IL10 and NAMPT known to be involved in CLL protection from apoptosis (p<0.05). We focused our attention on IL-10 and we demonstrated that treatment with ibrutinib for 24h improves NLCs secretion of IL-10. CD19+ CLL cells stimulated with IL-10 in a dose escalation experiment (from 0.1 ng/ml to 100 ng/ml) show good protection from apoptosis at different doses at different time-points. We then analyzed the ability of ibrutinib to abrogate the pro-survival signal induced by IL10 stimulation (1 ng/ml) in CD19+ CLL cells after 24-48h of culture. Ibrutinib does not completely antagonize the ability of IL-10 to protect CLL cells from apoptosis and to activate pSTAT3 and pERK signaling pathways. In accordance, ibrutinib is able to potentiate the immunosuppressive and permissive profile of NLCs stimulating the expression of CD163, CD206 and the activation of pSTAT6 with a concomitant inhibition of pSTAT1.
Conclusion
The ability of ibrutinib to effectively disrupt the crosstalk between CLL cells and NLCs is still unclear. Our data demonstrate that ibrutinib may also target NLCs, potentiating their permissive features through the secretion of unwanted survival factors such as IL-10. .
Session topic: E-poster
Keyword(s): Chronic lymphocytic leukemia, Immunomodulation, Microenvironment, Signal transduction
{{ help_message }}
{{filter}}