Centrocyte

File:Histopathology of centrocytes in follicular lymphoma.jpg

Centrocyte is a type of B cell found within the germinal centers of lymph nodes. These cells are crucial in the immune system's response to antigens, particularly in the process of affinity maturation and class switch recombination. Centrocytes are characterized by their small size, condensed chromatin, and cleaved or indented nuclei, distinguishing them from their precursors, the centroblasts.

Characteristics

Centrocytes are the smaller, non-dividing descendants of centroblasts and play a pivotal role in the humoral immune response. After undergoing rapid proliferation, centroblasts differentiate into centrocytes. These cells then participate in the selection process, where those with high-affinity B cell receptors (BCRs) for the antigen are selected for survival and further differentiation. This selection occurs through interactions with follicular dendritic cells (FDCs) and T follicular helper cells (Tfh cells) within the germinal centers.

Function

The primary function of centrocytes is to undergo the processes of affinity maturation and class switch recombination. Affinity maturation enhances the ability of antibodies to bind specifically and strongly to an antigen. This process involves somatic hypermutation of the variable region of the BCR gene, followed by selection for B cells that bind antigen with high affinity. Class switch recombination, on the other hand, allows the B cell to produce antibodies of different isotypes, enabling various effector functions such as neutralization, opsonization, and activation of the complement system.

Clinical Significance

Alterations in centrocyte function or regulation can lead to various immunodeficiency disorders or contribute to the development of lymphoma. For instance, aberrant activation or proliferation of centrocytes can be observed in certain types of B-cell lymphomas, such as Follicular lymphoma, which is characterized by the uncontrolled growth of centrocytes and centroblasts within lymph nodes.

See Also

• B cell
• Germinal center
• Lymph node
• Immune system
• Follicular lymphoma