B Cells Antibodies Humoral Immunity Activated Antigens Pathogen

Humoral immunity (body responds to antigens outside cells and APCs, humoral immunity system produces antibodies soluble in blood/tissue fluid, 

- B lymphocytes have antibodies (IgM), once pathogen (with specific antigen/toxins acting as antigens) enters, B cell with complementary antibodies bind, engulfs and processed antigens to become APCs

- activated T helper cells bind to B cell APC (clonal selection, which is the point where B cell with correct antibody cloned), interleukins produced by activated T helper cells activate B cells

- activated B cell divides to give clones of plasma/B memmory cells (clonal expansion)

- cloned plasma cells produce antibodies that fit antigens, they bind and disable them, or act as opsonins/agglutinins (primary immune response, which takes days/weeks for full effectivness so symptoms before PIR fully operational

- some cloned B cells develop into B memmory cells, which upon second invasion, divide into plasma cell clones, producing right antibody to wipe out pathogen before it causes symptoms (secondary immune response)