Question

What is the difference between the immature and naïve lymphocyte?

Answer 1

Immature lymphocytes differentiate to form mature lymphocytes when an antigen binds to it.

Lymphocytes which have not met a specific antigen and therefore did not have the opportunity to be activated by the antigen and subsequently be differentiated into memory and efficient cells. All lymphocytes that leave the central lymphoid organs are called naive lymphocytes. Those leaving bone marrow are naive B lymphocytes and those leaving the thymus are naive T lymphocytes.

Naive strictly means that an adaptive lymphocyte (either a B-cell or a T-cell) has not been exposed to their complementary antigen.

Immature B-cells can only express IgM i.e, there will be no other isotypes at this stage. However, Naive mature B-cells can express IgM and IgD.