Studies in humans and mice indicate the critical role of the surrogate light chain in the selection of the productive immunoglobulin repertoire during B cell development. However, subsequent studies using mutant mice have also demonstrated that alternative pathways are allowed. Our recent investigation has shown that some species, such as pig, physiologically use preferential rearrangement of authentic light chains, and become independent of surrogate light chains. Here we summarize the findings from swine and compare them with results in other species. In both groups, allelic and isotypic exclusions remain intact, so the different processes do not alter the paradigm of B-cell monospecificity. Both groups also retained some other essential processes, such as segregated and sequential rearrangement of heavy and light chain loci, preferential rearrangement of light chain kappa before lambda, and functional κ-deleting element recombination. On the other hand, the respective order of heavy and light chains rearrangement may vary, and rearrangement of the light chain kappa and lambda on different chromosomes may occur independently. Studies have also confirmed that the surrogate light chain is not required for the selection of the productive repertoire of heavy chains and can be substituted by authentic light chains. These findings are important for understanding evolutional approaches, redundancy and efficiency of B-cell generation, dependencies on other regulatory factors, and strategies for constructing therapeutic antibodies in unrelated species. The results may also be important for explaining interspecies differences in the proportional use of light chains and for the understanding of divergences in rearrangement processes. Therefore, the division into two groups may not be definitive and there may be more groups of intermediate species.

• MeSH
• alely MeSH
• B-lymfocyty MeSH
• geny pro imunoglobuliny * MeSH
• imunoglobuliny - kappa-řetězce * genetika   MeSH
• myši MeSH
• náhradní lehké řetězce imunoglobulinů genetika   MeSH
• prasata MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

TCF3-HLF-positive acute lymphoblastic leukemia (ALL) is currently incurable. Using an integrated approach, we uncovered distinct mutation, gene expression and drug response profiles in TCF3-HLF-positive and treatment-responsive TCF3-PBX1-positive ALL. We identified recurrent intragenic deletions of PAX5 or VPREB1 in constellation with the fusion of TCF3 and HLF. Moreover somatic mutations in the non-translocated allele of TCF3 and a reduction of PAX5 gene dosage in TCF3-HLF ALL suggest cooperation within a restricted genetic context. The enrichment for stem cell and myeloid features in the TCF3-HLF signature may reflect reprogramming by TCF3-HLF of a lymphoid-committed cell of origin toward a hybrid, drug-resistant hematopoietic state. Drug response profiling of matched patient-derived xenografts revealed a distinct profile for TCF3-HLF ALL with resistance to conventional chemotherapeutics but sensitivity to glucocorticoids, anthracyclines and agents in clinical development. Striking on-target sensitivity was achieved with the BCL2-specific inhibitor venetoclax (ABT-199). This integrated approach thus provides alternative treatment options for this deadly disease.

• MeSH
• aktivátorový protein specifický pro B-buňky genetika   MeSH
• akutní lymfatická leukemie farmakoterapie   genetika   mortalita   MeSH
• antitumorózní látky farmakologie   terapeutické užití   MeSH
• chemorezistence MeSH
• exprese genu MeSH
• fúzní onkogenní proteiny genetika   metabolismus   MeSH
• genetické asociační studie MeSH
• genomika MeSH
• inhibiční koncentrace 50 MeSH
• Kaplanův-Meierův odhad MeSH
• kohortové studie MeSH
• kokultivační techniky MeSH
• lidé MeSH
• mutace MeSH
• mutační analýza DNA MeSH
• myši inbrední NOD MeSH
• myši SCID MeSH
• náhradní lehké řetězce imunoglobulinů genetika   MeSH
• sekvenční delece MeSH
• xenogenní modely - testy antitumorózní aktivity MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

When a BCR on a mature B cell is engaged by its ligand, the cell becomes activated, and the Ab-mediated immune response can be triggered. The initiation of BCR signaling is orchestrated by kinases of the Src and Syk families. However, the proximal BCR-induced phosphorylation remains incompletely understood. According to a model of sequential activation of kinases, Syk acts downstream of Src family kinases (SFKs). In addition, signaling independent of SFKs and initiated by Syk has been proposed. Both hypotheses lack sufficient evidence from relevant B cell models, mainly because of the redundancy of Src family members and the importance of BCR signaling for B cell development. We addressed this issue by analyzing controlled BCR triggering ex vivo on primary murine B cells and on murine and chicken B cell lines. Chemical and Csk-based genetic inhibitor treatments revealed that SFKs are required for signal initiation and Syk activation. In addition, ligand and anti-BCR Ab-induced signaling differ in their sensitivity to the inhibition of SFKs.

• MeSH
• aktivace enzymů imunologie   MeSH
• buněčné linie MeSH
• intracelulární signální peptidy a proteiny metabolismus   fyziologie   MeSH
• kultivované buňky MeSH
• kur domácí MeSH
• modely u zvířat MeSH
• myši inbrední C57BL MeSH
• myši transgenní MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• receptory antigenů B-buněk metabolismus   fyziologie   MeSH
• receptory pre-B lymfocytů metabolismus   fyziologie   MeSH
• signální transdukce imunologie   MeSH
• skupina kinas odvozených od src-genu metabolismus   fyziologie   MeSH
• tyrosinkinasy metabolismus   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH