Question

A. Discuss the importance of the bone marrow stroma for B-cell development.

B. What would be the effect of anti-IL-7 antibodies on the development of B cells in the bone marrow, and at which stage would development be impaired? Explain your answer.

C. What is MHC restriction? How is it achieved during T-cell development?

D. How is self-tolerance achieved during B- and T-cell development?

Answer 1

Answer : Question A

In bone marrow, hematopoietic cells grow and mature on a meshwork of stromal cells, which are nonhematopoietic cells that support the growth and differentiation of hematopoietic cells. Stromal cells include fat cells, endothelial cells, fibroblasts, and macrophages. Stromal cells influence the differentiation of hematopoietic stem cells by providing a hematopoietic-inducing microenvironment consisting of a cellular matrix and factors that promote growth and differentiation. Many of these hematopoietic growth factors are soluble agents that arrive at their target cells by diffusion, others are membrane-bound molecules on the surface of stromal cells that require cell-to-cell contact between the responding cells and the stromal cells.