Gene expression from mouse models of B cell lymphomagenesis driven by gp130 signaling

This study examines the transcriptional changes invoked by activation of gp130 signaling in different mouse models of B cell lymphomagenesis. In order to study the in vivo effects of aberrant activity of IL-6/IL-6R/gp130-JAK/STAT3 signaling, we designed a transgene that allows conditional expression of L-gp130 by generating a ROSA26 knock-in mouse strain where compound L-gp130 and ZsGreen expression from the CAG promoter is prevented by a loxP- and a rox-flanked stop cassette. Total RNA extracted from purified B cells from young CD19Cre+/- ;L-gp130fl/+ and wildtype control mice was sequenced using unique molecular identifiers (UMI) in a paired end design where read1 corresponds to the cDNA and read2 contains the UMI. Furthermore, aging CD19Cre+/- ;L-gp130fl/+ animals developed tumors located predominantly in mesenteric lymph nodes. Infiltration of CD19;L-gp activated B cells was determined by Flow Cytometry and ZsGreen expression. Total RNA from tumors generally containing >60% ZsGreen+ cells was profiled as described above, for tumors with lower CD19;L-gp activated B cell content FACS was applied. In order to study the effects of activated IL-6/IL-6R/gp130-JAK/STAT3 signaling on Eµ-Myc-driven lymphomagenesis, CD19Cre;L-gp130fl;Eµ-Myc triple transgenic mice were generated and fetal liver hematopoietic stem/progenitor cell (FL-HSPC) grafts were transplanted into lethally irradiated syngeneic mice alongside FL-HSPC from CD19Cre;L-gp130f and Eµ-Myc control mice. Lastly, IL-6/IL-6R/gp130-JAK/STAT3 signaling was activated in the entire hematopoetic system using Vav1Cre resulting in Vav1Cre+/- ;L-gp130fl/+ animals. Independent of the time point of activation during hematopoietic and B cell differentiation, all Cre;L-gp compound mice succumbed to tumors of B cell origin.