[Basic principles of the humoral immune response].

Lymphocytes carry on their cell surface receptors capable of specifically recognizing substances foreign to the organism. During the humoral immune response these foreign substances bind to the receptors of B lymphocytes and induce these cells to divide, to produce increased amounts of the receptors and to secrete the receptors in the form of soluble immunoglobulins into the extracellular milieu. This process requires the participation of T helper lymphocytes, factors called cytokines and organized microanatomic structures.