The germinal center (GC) reaction has a pivotal function in human B-cell lymphomagenesis. Genetic aberrations occurring during somatic hypermutation and class switch recombination deregulate key factors controlling B-cell physiology and proliferation. Several human lymphoma entities are characterized by a constitutive GC phenotype and ongoing somatic hypermutation, but the molecular basis for this phenomenon is only partly understood. We have investigated the reasons for a constitutive GC-like program in Burkitt's lymphoma cells. Here, overexpression of c-Myc leads to a centroblast phenotype, promotes high constitutive expression of the key GC factors Bcl-6, E2A and activation-induced cytidine deaminase and contributes to proliferation and somatic hypermutation. Our findings elucidate how the activity of a pivotal transcription factor may freeze B-cell lymphoma cells in a constitutive GC-like state that is even maintained at an extrafollicular location.
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http://dx.doi.org/10.1038/onc.2009.377 | DOI Listing |
PLoS Pathog
January 2025
Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand.
Expansion of atypical memory B cells (aMBCs) was demonstrated in malaria-exposed individuals. To date, the generation of P. vivax-specific aMBCs and their function in protective humoral immune responses is unknown.
View Article and Find Full Text PDFAm J Clin Exp Immunol
December 2024
Department of Surgery, Medical Faculty, Trakia University Stara Zagora, Bulgria.
Tertiary lymphoid structures (TLS), formerly recognized as Crohn's-like structures, serve as crucial biomarkers for evaluating the progression of colorectal cancer (CRC). Understanding their spatial distribution, cellular composition, and interactions within CRC is paramount for comprehending the immune response in the tumor microenvironment (TME). TLS are comprised of a T-cellular compartment and a B-cellular compartment, the latter encompassing follicular dendritic cells (FDCs), high endothelial venules (HEVs), and lymphatic vessels.
View Article and Find Full Text PDFThe current understanding of humoral immune response in cancer patients suggests that tumors may be infiltrated with diffuse B cells of extra-tumoral origin or may develop organized lymphoid structures, where somatic hypermutation and antigen-driven selection occur locally. These processes are believed to be significantly influenced by the tumor microenvironment through secretory factors and biased cell-cell interactions. To explore the manifestation of this influence, we used deep unbiased immunoglobulin profiling and systematically characterized the relationships between B cells in circulation, draining lymph nodes (draining LNs), and tumors in 14 patients with three human cancers.
View Article and Find Full Text PDFZhonghua Zhong Liu Za Zhi
January 2025
Department of Pathology, China-Japan Friendship Hospital, Beijing100029, China.
To analyze the clinical significance of molecular classification and hereditary phenotype in endometrial carcinoma (EC) based on high throughput sequencing (NGS). 97 EC samples were collected retrospectively from December 2019 to October 2022 in China-Japan Friendship Hospital. NGS technique was used to analyze the molecular classification, POLE hypermutation, microsatellite high Instability/mismatch repair dysfunction (MSI-H/MMRd), P53 protein abnormality (P53 abn), and non-specific molecular profile (NSMP).
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Henan Province Engineering Research Center of Innovation for Synthetic Biology, School of Life Sciences and Technology, Xinxiang Medical University, Xinxiang, 453003, Henan, China; School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, 453003, Henan, China. Electronic address:
The mechanisms underlying antigen receptor germline gene diversification have always been a topic of intensive study. Here, we discovered that the frequency of stem-loop sequences in the antigen receptor germline gene region is remarkably higher than the genomic background. By analyzing these stem-loop sequences' similarity and distribution patterns, we found that clustered regularly interspaced homologous stem-loop pairs (CRIHSP) are widely present on the germline genes of antigen receptors in different species.
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