Project description:A missense mutation (G158R) in Aiolos, encoded by Ikzf3 gene, resulted in defective generation of B cells in mice. Pre-B cells were profoundly decreased in homozygous mutant mice. Heterozygous mutant mice showed milder B cell developmental defects, and B cells in the secondary lymphoid organs decreased. Genome-wide binding of Aiolos and Ikaros were altered in the thymus of homozygous Ikzf3 G158R mice. Our findings indicate that Aiolos-G158R hinders B cell development by interfering Ikaros' function via formation of heterodimers. A heterozygous missense variant (G159R) in AIOLOS, encoded by IKZF3 gene, resulted in impaired adaptive immunity, which predominantly manifested as profound B cell developmental defect. Genome-wide binding of wild-type AIOLOS and AIOLOS G159R mutant were examined in IKZF3 knock-out human pre-B cell line NALM-6, retrovirally transduced with doxycycline inducible wild-type AIOLOS or AIOLOS G159R. Changes in genome-wide binding and binding motif were observed for AIOLOS G159R mutant.
Project description:A missense mutation (G158R) in Ikzf3 gene resulted in defective generation of B cells in mice. Pre-B cells were profoundly decreased in homozygous mutant mice. Heterozygous mutant mice showed milder B cell developmental defects, and decreased B cells in the secondary lymphoid organs were observed. Ikzf3 encodes Aiolos, which makes heterodimer with Ikaros. Our findings indicate that the loss-of-function mutation in Aiolos hinders B cell development by interfering Ikaros' function via formation of heterodimers.
Project description:Purpose: Cereblon (CRBN), a substrate receptor of the E3 ubiquitin ligase complex CRL4CRBN, is the target of the small molecules lenalidomide (Len) and avadomide (Ava). Upon binding of the drugs, Aiolos and Ikaros are recruited to the E3 ligase, ubiquitylated and subsequently degraded. In DLBCL cells, Aiolos and Ikaros are direct transcriptional repressors of interferon stimulated genes (ISG) and degradation of these substrates results in increased ISG protein levels resulting in decreased proliferation and apoptosis. Herein, we aimed to uncover the mechanism(s) Aiolos and Ikaros use to repress ISG transcription and provide a mechanistic rationale for a combination strategy enhance cell autonomous activites of CELMoDs. Results: We describe that in DLBCL, the repression of ISG transcription is accomplished in part through recruitment of large transcriptional complexes such as the nucleosome remodeling and deacetylase (NuRD) which modify the chromatin landscape of these promoters. A rational combination approach of Ava with a specific HDAC inhibitor leads to a significant increase in ISG transcription compared to either single agent, and synergistic antiproliferative activity in DLBCL cell lines. Conclusion: Our results provide a novel role for lineage factors Aiolos and Ikaros in DLBCL as well as further insight into the mechanism(s) of Aiolos and Ikaros mediated transcriptional repression and unique therapeutic combination strategies.
Project description:Recent studies have demonstrated that the immunomodulatory drugs (IMiDs) lead to the degradation of the transcription factors Ikaros and Aiolos. However, why their loss subsequently leads to multiple myeloma (MM) cell death remains unclear. Using CRISPR-Cas9 genome editing, we have deleted IKZF1 and IKZF3 in human MM cell lines to gain further insight into their downstream gene regulatory networks. Our findings strongly support the central role of Ikaros and Aiolos in the action of the IMiDs. Inactivation of either factor alone recapitulates the cell intrinsic action of the IMiDs, resulting in cell cycle arrest and induction of apoptosis. Furthermore, evaluation of the transcriptional changes resulting from their loss demonstrates striking overlap with lenalidomide treatment.
Project description:Intestinal intraepithelial lymphocytes (IEL) are capable of rapid innate-like responses to microenvironmental cues. While poised to activation, IEL effector functions must be stringently controlled. Aiolos is an Ikaros zinc finger (IKZF) family member encoded by Ikzf3 that promotes histone deacetylation. Here, we found that Aiolos is a crucial regulator of IEL activation. Ikzf3–/– CD8αα+ IEL expressed high levels of innate NK receptors, cytotoxic enzymes, cytokines and chemokines. Single cell RNAseq of IEL revealed that Ikzf3 deficiency mostly amplified the effector machinery of a CD8αα+ IEL subset characterized by high expression CD122, the receptor for IL-15. Furthermore, Ikzf3 deficiency increased IEL responsiveness to IL-15. Aiolos binding sites were close to those for STAT5 and RUNX transcription factors that promote IL-15 signaling and cytolytic programs, respectively; lack of Ikzf3 increased accessibility and histone acetylation of these chromatin regions. Ikzf3 deficiency increased susceptibility to colitis, demonstrating the functional relevance of Aiolos-mediated regulation of IEL effector functions.
Project description:Intestinal intraepithelial lymphocytes (IEL) are capable of rapid innate-like responses to microenvironmental cues. While poised to activation, IEL effector functions must be stringently controlled. Aiolos is an Ikaros zinc finger (IKZF) family member encoded by Ikzf3 that promotes histone deacetylation. Here, we found that Aiolos is a crucial regulator of IEL activation. Ikzf3–/– CD8αα+ IEL expressed high levels of innate NK receptors, cytotoxic enzymes, cytokines and chemokines. Single cell RNAseq of IEL revealed that Ikzf3 deficiency mostly amplified the effector machinery of a CD8αα+ IEL subset characterized by high expression CD122, the receptor for IL-15. Furthermore, Ikzf3 deficiency increased IEL responsiveness to IL-15. Aiolos binding sites were close to those for STAT5 and RUNX transcription factors that promote IL-15 signaling and cytolytic programs, respectively; lack of Ikzf3 increased accessibility and histone acetylation of these chromatin regions. Ikzf3 deficiency increased susceptibility to colitis, demonstrating the functional relevance of Aiolos-mediated regulation of IEL effector functions.
Project description:Intestinal intraepithelial lymphocytes (IEL) are capable of rapid innate-like responses to microenvironmental cues. While poised to activation, IEL effector functions must be stringently controlled. Aiolos is an Ikaros zinc finger (IKZF) family member encoded by Ikzf3 that promotes histone deacetylation. Here, we found that Aiolos is a crucial regulator of IEL activation. Ikzf3–/– CD8αα+ IEL expressed high levels of innate NK receptors, cytotoxic enzymes, cytokines and chemokines. Single cell RNAseq of IEL revealed that Ikzf3 deficiency mostly amplified the effector machinery of a CD8αα+ IEL subset characterized by high expression CD122, the receptor for IL-15. Furthermore, Ikzf3 deficiency increased IEL responsiveness to IL-15. Aiolos binding sites were close to those for STAT5 and RUNX transcription factors that promote IL-15 signaling and cytolytic programs, respectively; lack of Ikzf3 increased accessibility and histone acetylation of these chromatin regions. Ikzf3 deficiency increased susceptibility to colitis, demonstrating the functional relevance of Aiolos-mediated regulation of IEL effector functions.
Project description:Intestinal intraepithelial lymphocytes (IEL) are capable of rapid innate-like responses to microenvironmental cues. While poised to activation, IEL effector functions must be stringently controlled. Aiolos is an Ikaros zinc finger (IKZF) family member encoded by Ikzf3 that promotes histone deacetylation. Here, we found that Aiolos is a crucial regulator of IEL activation. Ikzf3–/– CD8αα+ IEL expressed high levels of innate NK receptors, cytotoxic enzymes, cytokines and chemokines. Single cell RNAseq of IEL revealed that Ikzf3 deficiency mostly amplified the effector machinery of a CD8αα+ IEL subset characterized by high expression CD122, the receptor for IL-15. Furthermore, Ikzf3 deficiency increased IEL responsiveness to IL-15. Aiolos binding sites were close to those for STAT5 and RUNX transcription factors that promote IL-15 signaling and cytolytic programs, respectively; lack of Ikzf3 increased accessibility and histone acetylation of these chromatin regions. Ikzf3 deficiency increased susceptibility to colitis, demonstrating the functional relevance of Aiolos-mediated regulation of IEL effector functions.
Project description:Analysis of transcriptional profiling change comparing A549 cells expressing control empty vector and A549 cells expressing Aiolos. Results provide insight into molecular mechanisms underlying functional consequence of ectopic expression of Aiolos in solid cancer cells. Two-condition experiment, A549-empty vs. A549-Aiolos cells. Biological replicates: 3 control, 3 transfected, independently grown and harvested. One replicate per array.