ANATOMY

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 cells activate humoral immunity, whereas T cells activate cell-mediated immunity. The major difference between humoral and cell-mediated immunity is that humoral immunity produces antigen-specific antibodies, whereas cell-mediated immunity does not.

Detailed explanation-3: -Humoral immunity is also called antibody-mediated immunity. With assistance from helper T cells, B cells will differentiate into plasma B cells that can produce antibodies against a specific antigen. The humoral immune system deals with antigens from pathogens that are freely circulating, or outside the infected cells.

Detailed explanation-4: -T helper cells aid in both the humoral and cellular immune response. CD4* T cells are helper cells that bind to the major histocompatibility complex (MHC) II class molecules on B cells and antigen-pressing cells (APCs).

Detailed explanation-5: -T cells regulate the activities cells participating in immune responses. They provide help for antibody production by B cells, and they are also the effectors of antigen-specific cell-mediated immunity (CMI).