Humoral Immunity

B lymphocytes, i. e. white blood cells, origin in bone marrow.

Antibody proteins are present on the cell’s surface and are receptors that enable combining antigens. Binding antigens stimulate cell division, lymphocyte multiply into clones. Some of them became plasma cells and produce antibodies. Differentiating into plasma cells is caused by interleukins presence. This proteins are secreted by helper T cells after binding with antigens. Some of the clones became long-lived memory cells that quicken immune response should the same antigen appear again. Exposure to the antigen, for example vaccine, immunizes organism for several years.