Bsejtklón

Bsejtklón, or B-sejtklón in Hungarian, refers to a population of B lymphocytes descended from a single progenitor cell and sharing the same B-cell receptor (BCR). In immunology, a clone represents a group of cells that recognize the same antigen epitope and have a common genetic origin.

Origin and characteristics describe how a B cell clone forms and how it functions in an immune response. When a B cell binds its specific antigen and receives help from helper T cells, it proliferates to form a clonal expansion. All members of the resulting clone express the same BCR, enabling a targeted and coordinated response against the antigen. In germinal centers, the clone may undergo somatic hypermutation and class switch recombination, increasing antibody affinity and altering antibody isotype.

Outcomes of clonal expansion include differentiation into antibody-secreting plasma cells and the formation of memory B cells, which provide longer-lasting protection. Clonality is a key feature in both normal immunity and disease. It can be assessed diagnostically by detecting restricted light-chain expression (kappa versus lambda) through flow cytometry or by analyzing immunoglobulin gene rearrangements with molecular methods to confirm a dominant B-cell clone.

Clinical relevance encompasses both protective and pathological roles. Dominant B-cell clones drive normal humoral responses to pathogens and vaccines, but malignant B-cell clones underpin certain hematologic cancers, such as chronic lymphocytic leukemia and some lymphomas. Monitoring clonality aids diagnosis, prognosis, and tracking of disease burden. In research and therapy, cloning concepts underpin monoclonal antibody production and advances in BCR sequencing to map immune repertoires.