THE JAK1/2 INHIBITOR RUXOLITINIB MODULATES ANTIGEN PRESENTING FUNCTIONS OF ACTIVATED PRIMARY B CELLS ON A METABOLIC LEVEL
(Abstract release date: 05/19/16)
EHA Library. Theurich S. 06/09/16; 132665; E1116
Dr. Sebastian Theurich
Contributions
Contributions
Abstract
Abstract: E1116
Type: Eposter Presentation
Background
B lymphocytes not only balance the physiologic immune response but can also be involved in a variety of immune pathologies. Besides their traditional function as antibody producing plasma cells, it has been shown that B cells, upon activation, can develop into professional antigen-presenting cells (APCs) which mediate further cellular immune responses. Moreover, cytokines modulate B cell activation via the Janus kinase - signal transducer and activator of transcription (JAK-STAT) pathway. Inhibition of the JAK-STAT pathway has been introduced into clinical practice with the specific JAK1/2 inhibitor ruxolitinib. Approved for the treatment of JAK2 mutated myeloproliferative diseases, ruxolitinib has also shown to alleviate immune mediated symptoms such as fatigue and night sweat. Also in steroid-refractive graft-versus-host disease, ruxolitinib has shown activity.
Aims
Given the broad employment of JAK-STAT signaling in immune responses and the suggested clinical benefits of ruxolitinib mediated JAK1/2 inhibition in immune pathologies, we analyzed if such “off-target” effects can also mediate B cell activation.
Methods
Primary human B cells from healthy donors as well as from ruxolitinib treated patients were used for in vitro analyses. Here, CD40ligand mediated B-cell activation was applied as a well established model for T-cell dependent B-cell activation. Morphologic, phenotypic and functional changes were analyzed by 10-color flow cytometry. Cell metabolism was analyzed via extracellular flux changes (Seahorse Bio.).
Results
We found that ruxolitinib treatment significantly suppressed CD40L induced B-cell activation. These alterations became manifest in a reduced cell size and less homotypic cluster formation as well as in a reduced expression of co-stimulatory (CD80, CD86) and HLA-class-II molecules. On a functional level, JAK1/2 inhibition significantly reduced the ability of CD40L activated B cells to induce T-cell activation in a mixed allogeneic lymphocyte reaction. As a mechanism of action we found that ruxolitinib reduced glycolysis and the glycolytic capacity of activated B cells. Vice versa, inhibition of glycolysis via 2-deoxyglucose could recapitulate the ruxolitinib induced phenotype. Finally, data from ruxolitinib treated patients suggest that similar alterations of B cells also occur in vivo.
Conclusion
Taken together, our data suggest that ruxolitinib has important effects on B-cell activation which might contribute to its previously reported immunosuppressive features. Furthermore, we show that ruxolitinib can modulate APC-features of activated human B cells via glycolysis.
Session topic: E-poster
Keyword(s): Antigen presentation, B cell, Immune response, Ruxolitinib
Type: Eposter Presentation
Background
B lymphocytes not only balance the physiologic immune response but can also be involved in a variety of immune pathologies. Besides their traditional function as antibody producing plasma cells, it has been shown that B cells, upon activation, can develop into professional antigen-presenting cells (APCs) which mediate further cellular immune responses. Moreover, cytokines modulate B cell activation via the Janus kinase - signal transducer and activator of transcription (JAK-STAT) pathway. Inhibition of the JAK-STAT pathway has been introduced into clinical practice with the specific JAK1/2 inhibitor ruxolitinib. Approved for the treatment of JAK2 mutated myeloproliferative diseases, ruxolitinib has also shown to alleviate immune mediated symptoms such as fatigue and night sweat. Also in steroid-refractive graft-versus-host disease, ruxolitinib has shown activity.
Aims
Given the broad employment of JAK-STAT signaling in immune responses and the suggested clinical benefits of ruxolitinib mediated JAK1/2 inhibition in immune pathologies, we analyzed if such “off-target” effects can also mediate B cell activation.
Methods
Primary human B cells from healthy donors as well as from ruxolitinib treated patients were used for in vitro analyses. Here, CD40ligand mediated B-cell activation was applied as a well established model for T-cell dependent B-cell activation. Morphologic, phenotypic and functional changes were analyzed by 10-color flow cytometry. Cell metabolism was analyzed via extracellular flux changes (Seahorse Bio.).
Results
We found that ruxolitinib treatment significantly suppressed CD40L induced B-cell activation. These alterations became manifest in a reduced cell size and less homotypic cluster formation as well as in a reduced expression of co-stimulatory (CD80, CD86) and HLA-class-II molecules. On a functional level, JAK1/2 inhibition significantly reduced the ability of CD40L activated B cells to induce T-cell activation in a mixed allogeneic lymphocyte reaction. As a mechanism of action we found that ruxolitinib reduced glycolysis and the glycolytic capacity of activated B cells. Vice versa, inhibition of glycolysis via 2-deoxyglucose could recapitulate the ruxolitinib induced phenotype. Finally, data from ruxolitinib treated patients suggest that similar alterations of B cells also occur in vivo.
Conclusion
Taken together, our data suggest that ruxolitinib has important effects on B-cell activation which might contribute to its previously reported immunosuppressive features. Furthermore, we show that ruxolitinib can modulate APC-features of activated human B cells via glycolysis.
Session topic: E-poster
Keyword(s): Antigen presentation, B cell, Immune response, Ruxolitinib
Abstract: E1116
Type: Eposter Presentation
Background
B lymphocytes not only balance the physiologic immune response but can also be involved in a variety of immune pathologies. Besides their traditional function as antibody producing plasma cells, it has been shown that B cells, upon activation, can develop into professional antigen-presenting cells (APCs) which mediate further cellular immune responses. Moreover, cytokines modulate B cell activation via the Janus kinase - signal transducer and activator of transcription (JAK-STAT) pathway. Inhibition of the JAK-STAT pathway has been introduced into clinical practice with the specific JAK1/2 inhibitor ruxolitinib. Approved for the treatment of JAK2 mutated myeloproliferative diseases, ruxolitinib has also shown to alleviate immune mediated symptoms such as fatigue and night sweat. Also in steroid-refractive graft-versus-host disease, ruxolitinib has shown activity.
Aims
Given the broad employment of JAK-STAT signaling in immune responses and the suggested clinical benefits of ruxolitinib mediated JAK1/2 inhibition in immune pathologies, we analyzed if such “off-target” effects can also mediate B cell activation.
Methods
Primary human B cells from healthy donors as well as from ruxolitinib treated patients were used for in vitro analyses. Here, CD40ligand mediated B-cell activation was applied as a well established model for T-cell dependent B-cell activation. Morphologic, phenotypic and functional changes were analyzed by 10-color flow cytometry. Cell metabolism was analyzed via extracellular flux changes (Seahorse Bio.).
Results
We found that ruxolitinib treatment significantly suppressed CD40L induced B-cell activation. These alterations became manifest in a reduced cell size and less homotypic cluster formation as well as in a reduced expression of co-stimulatory (CD80, CD86) and HLA-class-II molecules. On a functional level, JAK1/2 inhibition significantly reduced the ability of CD40L activated B cells to induce T-cell activation in a mixed allogeneic lymphocyte reaction. As a mechanism of action we found that ruxolitinib reduced glycolysis and the glycolytic capacity of activated B cells. Vice versa, inhibition of glycolysis via 2-deoxyglucose could recapitulate the ruxolitinib induced phenotype. Finally, data from ruxolitinib treated patients suggest that similar alterations of B cells also occur in vivo.
Conclusion
Taken together, our data suggest that ruxolitinib has important effects on B-cell activation which might contribute to its previously reported immunosuppressive features. Furthermore, we show that ruxolitinib can modulate APC-features of activated human B cells via glycolysis.
Session topic: E-poster
Keyword(s): Antigen presentation, B cell, Immune response, Ruxolitinib
Type: Eposter Presentation
Background
B lymphocytes not only balance the physiologic immune response but can also be involved in a variety of immune pathologies. Besides their traditional function as antibody producing plasma cells, it has been shown that B cells, upon activation, can develop into professional antigen-presenting cells (APCs) which mediate further cellular immune responses. Moreover, cytokines modulate B cell activation via the Janus kinase - signal transducer and activator of transcription (JAK-STAT) pathway. Inhibition of the JAK-STAT pathway has been introduced into clinical practice with the specific JAK1/2 inhibitor ruxolitinib. Approved for the treatment of JAK2 mutated myeloproliferative diseases, ruxolitinib has also shown to alleviate immune mediated symptoms such as fatigue and night sweat. Also in steroid-refractive graft-versus-host disease, ruxolitinib has shown activity.
Aims
Given the broad employment of JAK-STAT signaling in immune responses and the suggested clinical benefits of ruxolitinib mediated JAK1/2 inhibition in immune pathologies, we analyzed if such “off-target” effects can also mediate B cell activation.
Methods
Primary human B cells from healthy donors as well as from ruxolitinib treated patients were used for in vitro analyses. Here, CD40ligand mediated B-cell activation was applied as a well established model for T-cell dependent B-cell activation. Morphologic, phenotypic and functional changes were analyzed by 10-color flow cytometry. Cell metabolism was analyzed via extracellular flux changes (Seahorse Bio.).
Results
We found that ruxolitinib treatment significantly suppressed CD40L induced B-cell activation. These alterations became manifest in a reduced cell size and less homotypic cluster formation as well as in a reduced expression of co-stimulatory (CD80, CD86) and HLA-class-II molecules. On a functional level, JAK1/2 inhibition significantly reduced the ability of CD40L activated B cells to induce T-cell activation in a mixed allogeneic lymphocyte reaction. As a mechanism of action we found that ruxolitinib reduced glycolysis and the glycolytic capacity of activated B cells. Vice versa, inhibition of glycolysis via 2-deoxyglucose could recapitulate the ruxolitinib induced phenotype. Finally, data from ruxolitinib treated patients suggest that similar alterations of B cells also occur in vivo.
Conclusion
Taken together, our data suggest that ruxolitinib has important effects on B-cell activation which might contribute to its previously reported immunosuppressive features. Furthermore, we show that ruxolitinib can modulate APC-features of activated human B cells via glycolysis.
Session topic: E-poster
Keyword(s): Antigen presentation, B cell, Immune response, Ruxolitinib
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