Question

Deficiency in RAG-1 and/or RAG-2 can affect the proper development of which of the following cell types, resulting in decreased numbers of circulating cells of those types?

A. B cells
B. T cells
C. NK cells
D. Both A and B
E. All of the above

Answer 1

Deficiency in RAG-1 and/or RAG-2 impairs the development of both B cells and T cells, which are critical components of the adaptive immune system, but does not significantly affect NK cells.

Step-by-step explanation:

Deficiency in RAG-1 and/or RAG-2 can affect the proper development of B cells and T cells, resulting in decreased numbers of circulating cells of those types. The correct answer to the question is D. Both A and B. RAG-1 and RAG-2 are crucial for the recombination process that generates the diverse antigen receptor repertoire in B and T cells, and thus play an essential role in the adaptive immune system. Without these enzymes, the processes of V(D)J recombination cannot occur, leading to an inability to produce a diverse array of B cell receptors (BCRs) and T cell receptors (TCRs), which are essential for the specific immune response.

B cells mature in red bone marrow and are responsible for the production of antibodies that are part of the humoral immune response. T cells, which mature in the thymus after initial development in bone marrow, are vital for cell-mediated immune responses and include cytotoxic T cells, helper T cells, and suppressor T cells. Deficiencies in RAG enzymes predominantly affect these two types of lymphocytes; whereas natural killer (NK) cells, part of the innate immune system, are typically not affected by RAG deficiencies.

Answer 2

A deficiency in RAG-1 and RAG-2 negatively impacts the development and maturation of both B cells and T cells, leading to a decreased number of these cells in circulation.

Step-by-step explanation:

Deficiency in RAG-1 and/or RAG-2 can affect the proper development of B cells and T cells. Both of these cell types are crucial components of the adaptive immune system.

RAG proteins are essential for the rearrangement of immunoglobulin and T cell receptor genes, which is a critical step in the development of B cells in the bone marrow and T cells in the thymus. Without functional RAG proteins, these cells cannot properly mature, leading to a decrease in their numbers in the bloodstream and lymphoid organs.

Consequently, the correct option for which types of cells would have decreased circulation due to a deficiency in RAG proteins is D. Both A and B.