Question

Explain how the humoral immunity and cellular immunity work together.

Answer 1

Ans. -

Humoral immunity secretes antibodies to fight against antigens, whereas cell mediated immunity secretes cytokines and no antibodies to attack the pathogens. The Humoral immunity is rapid or quick in their action against antigens, while the Cell mediated immunity show delay though permanent action against any pathogens. Lymphocytes, the cells competent to initiate immune responses, can be divided into two major groups: thymus derived or T cells responsible for cellular immunity and bursa derived or B cells which produce immunoglobulin molecules and are involved in humoral immunity. Accessory cells, such as monocytes, polymorphonuclear leucocytes and mast cells act in an auxiliary manner by facilitating antigen processing or presentation, which modify the various manifestations of the immune response. Antigen activated T cells produce factors with various activities: some are involved in recruiting inflammatory cells, others activate macrophages and enhance their microbicidal activities, and others modify B-cell responsiveness either by facilitating it.

A variety of interactions between T and B cells and between lymphocytes and accessory cells have been described in both cellular and humoral immunity. These factors are T-cell regulation of immune responsiveness. Antibody produced by B cells also plays a role in immuno regulation, acting either as an immunopotentiating influence or as a negative feedback, e.g. when complexed with antigen, turning off the response of T or B cells.