Final answer:
V-J rearrangement occurs in both B and T cells. It is part of the immune system's process for generating diverse antigen receptors on naive B and T cells, allowing them to recognize many antigens and participate in both humoral and cell-mediated immune responses.
Step-by-step explanation:
V-J rearrangement occurs in both B and T cells. During the maturation of immune cells, V (Variable) and J (Joining) gene segments undergo recombination to create the variable region of B cell receptors (BCRs) and T cell receptors (TCRs). This genetic rearrangement is crucial for the immune system to produce a diverse array of receptors, enabling it to recognize a vast number of antigens. For B cells, this rearrangement occurs for the BCR light chain, whereas T cells undergo V-J rearrangement for the α chain of the TCR.
Naïve B and T cells, which have not yet encountered their specific antigen, contain receptors that are the result of this rearrangement process. Upon activation by an antigen, these cells can further differentiate and proliferate, with B cells producing antibodies as part of the humoral immune response, and T cells contributing to the cell-mediated immune response.