Search

Antibodies are molecules of glycoprotein nature that have ability to bind antigens either soluble or bound in membranes of cells in a specific way. They are present in plasma and in tissue fluids (lymph, saliva, tears etc.). As most of antibodies belong to the gamma globulins of plasma proteins, they were previously known under the term gammaglobulins; their contemporary nomenclature is immunoglobulins (Ig). There are five classes of immunoglobulins: IgG, IgM, IgA, IgE, and IgE, respectively. They have specific biochemical structure and function. The principal biological role is to bind antigens; except it, they can activate the complement, opsonise bacteria, bind to receptors of various cell of the immune system etc.

B lymphocytes are principal cells that mediate humoral adaptive immunity. After their maturation in the bone marrow, B cells enter peripheral lymphoid tissues, which are the sites of interaction with foreign antigens. Production of antibodies is initiated by the interaction of antigens with a small number of mature B cells specific for each antigen. An antigen binds to the membrane receptors on specific B cells and initiates a series of responses that lead to two principal changes: cell proliferation resulting in expansion of the clone, and differentiation to either plasma cells actively secreting antibodies or to memory cells.

Key words: B cells, subsets of B cells, memory B cells, plasma cells

Protein antigens are no able to induce an immune response without being previously processed by antigen presenting cells (APCs). Following their processing that comprises their splitting to smaller fragments – peptides, APs subsequently present them to T cells; moreover, they activate them and polarise to a specific biological functions. Depending of antigen origin, there are two presentation pathways, exogenous and endogenous. Antigens originated from outside of APC, e.g. bacterial toxins, enzymes, etc., are presented by exogenous pathway and presented molecules are class II HLA molecules. T cell, that recognise presented peptides belong to helper subset of T cells. Antigens originated in the cytosol, such as antigens that appear in the cytoplasm of virus infected cells, are presented by endogenous pathway and presented molecules belong to class I HL-A molecules. T cells, that recognise presented peptides, represent cytotoxic T cells.

Common people perceive Immunology as a scientific branch that studies defence of an organism against germs, cancer cells, toxins etc. Nowadays, Immunology is defined a scientific branch that studies immunity, its cellular and molecular processes that proceed after a foreign substance, an antigen, enters our body. There are many notable personalities who contributed to its development. Let us mention only some of them – Louis Pasteur, Ilja Mecnikov, Jean Dausset and many, many others. They contributed to the fact that Immunology belongs to those scientific disciplines that develop the most intensively in recent years.

Verejnosť vníma imunológiu ako vednú disciplínu, ktorá sa zaoberá štúdiom obranných mechanizmov proti mikroorganizmom, infekčným chorobám. Dnes však Imunológiu vnímame širšie, ako vednú disciplínu, ktorá študuje bunkové a molekulové procesy, ktoré sa odohrávajú v organizme človeka, či zvierat alebo rastlín po vniknutí akejkoľvek cudzej látky do tela. K rozvoju imunológie prispeli početné významné osobnosti, zmieňme sa len o takých velikánoch ako boli Louis Pasteur, Ilja Mečnikov, Jean Dausset a mnohí, mnohí ďalší; svedčia o tom Nobelove ceny, ktoré sa skoro každé 3 – 4 roky dostanú vedeckí pracovníci na poli imunológie. Táto skutočnosť je odrazom prudkého rozmachu tohto fascinujúceho vedného odboru a jeho veľkému významu pre biológiu a medicínu.