Lymphocytes against cancer

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Proteins cytoplasmic granules, causing damage to cell membranes, were called preparename. They are the same in the EC-cells, T-killer cells, eosinophils, cytotoxic macrophages and granulocytes and even pathogenic organisms (pathogens of dysentery), causing the death of the animal cells. However, lymphoid killers, except perforin, there is another protein that can not only increase the permeability of the membrane to the other cells, but also independently almost instantly kill her. This protein called cytolysin. Cytolysin has much in common with the factor of the 9th complement system and serine-protease, also in seconds destroy the cell, "labeled" connected with her antibody.
In lymphoid cells killer actions identified three genes, heads of synthesis of cytolysin (also called the lymphotoxin). The level of their expression and the intensity of the synthesis of proteins encoded by these genes depends on degree of activation of lymphocytes. Therefore, the scheme of inclusion of Killarney functions of lymphocytes can be represented by the following sequence: activation→cascade of serine proteases > stimulation of synthesis of perforin > products cytolysin-lymphotoxin→contact with the cell-target→selection of lymphotoxin, detrimental to the cytoplasm and cell DNA target.
Interestingly, between cytotoxic products allocated T-killer cells, and tumor necrosis factor (TNF) macrophages have a noticeable structural commonality: amino acid sequence on 30% the same. With TNF many analogies and also cytolysin EC-cells. Therefore, tumor cells cause different protective elements production in something similar biological products aimed at the destruction of the tumor mass. The effect Kiliya never cover harmless to the body cells.
For full immunological reactions the process of secretion of titlinov, despite rapid saturation of cells with these proteins, should last for a long time. It is necessary for specificity killer activity and for its reusable implementation. The effect of cell killing one cytotoxic lymphocyte can be repeated in relation to the second, third and even fourth target. Production of cytotoxic proteins necessary for directed migration killer and the correct orientation of its organelles: plate complex (the Golgi apparatus) and the system cytoplasmic microtubules are located towards the object of attack. Killing takes place after the close contact with lymphocyte membrane of the target, in which short shoots lymphocyte penetrate in time-holes in the body of the victim. The contents of protein granules is injected into the cytoplasm of the target sparingly, lymphotoxin not spent in vain not go to the free space.
This multi-stage process, which takes a relatively short period of time, includes the chain of events from the expression of genes of cicolatino to the stage of "legal shot". It is preceded by the activation of killer lymphocytes. This signal T-killer gets from T-helper in the form of interleikina-2 (IL-2). So defect maturation of cytotoxic lymphocytes may depend on insufficient production of proteins system perforin-cicolatino-lymphotoxin and distortion in the signal transmission from the IL-2. You cannot ignore other possible violations of T cells in cancer: the weakening of differentiation of T-predecessors in T-lymphocytes, actions soluble suppressor factor etc.