Antibodies. B cells
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 and plasma cells
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
Antigen presentation; T cell mediated immunity
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.
Milestones of Immunology, Immune system - an overview, Antigen
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.
Míľniky vývoja imunológie. Imuntný systém - prehľad. Antigén
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.
Foeto-maternal relationships. The immune system of newborns
.. secures it by various mechanisms – special cells, cytokines, HLA molecules, peripheral tolerance.. .. maternal immune response against HLA antigens of the foetus that it has inherited from its.. .. of a blastocyt, invasion of trophoblast cells into decidua and myometrium to enable them an.. ..keywords: NK cells, HLA molecules, tolerance, immune system of..
HLA complex and its significancein biology and medicine
.. derived from the words: “human leucocyte antigens” as its fist molecules were discovered in.. .. proteins present in membranes of all nucleated cells. They form a unique system for which the term.. .. and individuality, they mediate presentation of antigens to T cells, are involved in cooperation of.. .. they mediate presentation of antigens to T cells, are involved in cooperation of cells o the.. ..keywords: molecules, HLA system, chromosome 6, antigen presentation, transplantations, associations..
.. imunitná odpoveď začína po vstupe cudzorodých antigénov do organizmu alebo po objavení sa .. .. rozdiel v rozpoznávaní antigénu alfa/beta T- a B-lymfocytmi je v tom, že .. .. sa ako bunky prezentujúce antigén (antigen presenting cells - APC). Tie pohltený antigén &.. .. bunky prezentujúce antigén (antigen presenting cells - APC). Tie pohltený antigén &.. ..keywords: antigénov, HLA, CD1, MR1,.. .. [?] Klinicky citlivé [?] Licencia Prezentácia antigénov | 27.3.2013 4.13 MB užívateľ vzdelávacej siete ..
Hypersensitivity reactions, types II till V
.. be an inappropriate immune response to an antigen. Several forms of hypersensitive reaction can.. .. belong especially to potentially malignant cells that appear in our organisms as the results of a.. .. effector mechanisms with the aim to remove antigen. Under certain circumstances, however, this.. .. of T cells by antigen on appropriate antigen-presenting cells results in the secretion of various.. .. involve antibody-mediated destruction of cells. This type of reaction is best seen by..
Type I hypersensitivity (Allergy)
.. immediate hypersensitivity), within minutes of antigen challenge, and results in conspicuous clinical.. .. IgE class mediate this type of hypersensitivity; antigens that induce them are called allergens. IgE.. .. IgE antibodies bind to Fc receptors on mast cells and basophils. When these cell-associated..
Serological methods II
.. methods used to identify antibodies and antigens in patient sample. Up-to-date serological.. ..keywords: methods, antigen, antibodies, ELISA, RIA,.. ..keywords: methods, antigen, antibodies, ELISA, RIA,..
.. engulfment and their killing. The phagocytic cells of mammals belong to two complementary systems,.. .. into several steps: recruitment of inflammatory cells into a site where germs entered the body, local..
ENDOCRINE SYSTEM - part II
.. thymus, gonadal glands and also chromaffine cells.. ..keywords: epiphysis, thymus, gonadal glands, chromaffine cells..
Cytokines. PAMPs and PRRs
.. activation, proliferation and differentiation of cells of the immune system. Moreover, cytokines.. .. immunity recognises an infinite variety of antigens by millions of cell-surface receptors. Instead,.. .. without them. Moreover, they are not present in cells of their hosts. The term “Pathogen..
Serological methods I
.. methods used to identify antibodies and antigens in patient sample (serum, plasma)...