IMMUNOLOGY

Detailed explanation-1: -Helper T cells are arguably the most important cells in adaptive immunity, as they are required for almost all adaptive immune responses. They not only help activate B cells to secrete antibodies and macrophages to destroy ingested microbes, but they also help activate cytotoxic T cells to kill infected target cells.

Detailed explanation-2: -B cell activation is triggered by the binding of specific antigen to the BCR. The end result of this process will depend on the characteristics of the antigen, the B cell subpopulation activated, and the co-stimulatory signals provided by the antigen itself, T cells, and the microenvironment.

Detailed explanation-3: -B cells act as antigen presenting cells to induce T cell responses to specific antigens. B cells also have roles in development and maintenance of memory T cells (6, 66–68) to provide optimal T cell response to antigens in long-term antigen exposure.