Recognizing antigen

Interfaces play a predominant role in metabolic processes [78], as well as in immune recognition (e.g. T lymphocytes recognizing antigens on the surface of antigen presenting cells, section c2.14.6.2. Historically, the bulk of experimental... 

It is clear that generated by such a random process the initial repertoire of antigen specifity in all individuals of human beings should be quite similar. This implies that initially in each individal there develop lymphocytes which recognize antigens of this very individual, i.e. autoantigens. 

Genetic unresponsiveness. If the animal lacks the necessary genetic ability to recognize antigenic material it will be immunologically silent. 

Molecular recognition is critical for fife enzymes recognize substrates, antibodies recognize antigens, receptors recognize signaling molecules, and so on. 

Particles are most efficiently phagocytized when they are opsonized with complement components or immunoglobulins. This is accomplished by incubating the particles with autologous or normal human pooled serum, or with specific antibodies that recognize antigens on the particle surface. 

The receptors of the B lymphocytes recognize antigens in the form of foreign proteins, which exist in soluble, particle-boimd or cell-boimd forms. 

Note that the mechanism proposed for helper T-cell function requires that T cells have surface receptors that recognize antigen-processing cells, antigen itself, and the appropriate B cell. We will shortly discuss the nature of T-cell receptors, as well as the surface structures they recognize, in a broader context. 

There are three different kinds of lymphocytes that have specific functions T cells, B cells and NK cells. T cells develop in the thymus while B cells develop in the adult bone marrow. The thymus and the bone marrow are the primary lymphoid organs where lymphocytes acquire specific cell surface receptors that give them the ability to recognize antigens. NK cells are cytotoxic lymphocytes that develop in the bone marrow. The phagocytes are made up of either monocytes (macrophages) or polymorphonuclear granulocytes, which include neutrophils, eosinophils and basophils. 

After recognizing antigens through membrane-bound antibodies, there is B cell proliferation and differentiation for about 4-5 days. This results in the production of plasma and memory cells. One of the five classes of antibodies are produced and secreted by plasma cells that do not possess membrane-bound antibodies. Plasma cells survive for about 1-2 weeks. 

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