Which statement describes antigen-independent maturation of B lymphocytes?

Which statement describes antigen-independent maturation of B lymphocytes?

• A. It occurs in the thymus.
• B. It occurs in the bone marrow.
• C. It requires antigen stimulation.
• D. It occurs in the lymph nodes.

Answer: (B)

Antigen-independent maturation of B lymphocytes happens in the bone marrow. Here, precursor B cells undergo rearrangement of their immunoglobulin genes (V(D)J recombination) to form a functional B cell receptor, with survival and development guided by signals from bone marrow stromal cells and cytokines like IL-7. This process yields immature B cells that express surface IgM and then migrate to the periphery to become mature naive B cells. In contrast, the thymus is for T cell maturation, and lymph nodes are sites where mature B cells encounter antigen and participate in antigen-driven responses, which require antigen stimulation. Thus, the bone marrow is the site of antigen-independent B cell maturation.

Antigen-independent maturation of B lymphocytes happens in the bone marrow. Here, precursor B cells undergo rearrangement of their immunoglobulin genes (V(D)J recombination) to form a functional B cell receptor, with survival and development guided by signals from bone marrow stromal cells and cytokines like IL-7. This process yields immature B cells that express surface IgM and then migrate to the periphery to become mature naive B cells. In contrast, the thymus is for T cell maturation, and lymph nodes are sites where mature B cells encounter antigen and participate in antigen-driven responses, which require antigen stimulation. Thus, the bone marrow is the site of antigen-independent B cell maturation.