immune - modulating therapies ( drugs which adjust the activity of the immune response to a desired level), interferon beta-1b (Betaferon)
Monocyte A relatively large mononuclear leukocyte (16–22 4m in diameter), that normally constitutes 3–7% of the leukocytes of the circulating blood, and is normally found in lymph nodes, spleen, bone marrow, and loose connective tissue. When treated with the usual dyes, monocytes manifest an abundant pale blue or blue-gray cytoplasm that contains numerous, fine, dustlike, red-blue granules; vacuoles are frequently present; the nucleus is usually indented, or slightly folded, and has a stringy chromatin structure that seems more condensed where the delicate strands are in contact. See Also: monocytoid cell, endothelial leukocyte. Origin [mono- + G. kytos, cell]
This slide shows some features of the structure and functions of the Ab
Apoptosis: Programmed cell death; deletion of individual cells by fragmentation into membrane-bound particles, which are phagocytosed by other cells. Whereas some cells (e.g., cardiac and skeletal muscle fibers, CNS neurons) last a lifetime, others (e.g., epithelial and glandular cells, erythrocytes) have limited life-spans, at the end of which they are genetically programmed to self-destruct, usually to be replaced by others formed by mitosis from surviving cells. Cells in tissue cultures spontaneously undergo apoptosis after about 50 cell divisions . In contrast to cell death caused by injury, infection, or circulatory impairment, apoptosis elicits no inflammatory response in adjacent cells and tissues . Features of apoptosis detectable by histological and histochemical methods include cell shrinkage , due chiefly to dehydration; increased membrane permeability , with a rise in intracellular calcium and a fall in pH ; endonucleolysis (fragmentation of nuclear DNA); and ultimately formation of apoptotic bodies , which are absorbed and removed by macrophages . Besides being due to genetic programming, apoptosis can be induced by injury to cellular DNA, as by irradiation and some cytotoxic agents used to treat cancer. It can be suppressed by naturally occurring factors (e.g., cytokines) and by some drugs (e.g., protease inhibitors). Apoptosis typically does not occur in malignant cells. Such cells therefore escape the destiny of their nonmalignant precursor cells and are said to be immortal. Immortalization can occur in various ways. The bcl-2 gene, present in many cancers, directs the production of an enzyme that blocks apoptosis and immortalizes affected cells. Injury to DNA normally triggers apoptosis by activating the p53 tumor suppressor gene, which is missing or mutated in about one-half of all human cancers. Cells that lack this gene can survive chemotherapy and irradiation intended to destroy cancer cells. Failure of apoptosis to occur is also involved in some degenerative diseases, including lupus erythematosus, and may be responsible for cellular damage caused by certain viruses, including HIV. Origin [G. a falling or dropping off, fr. apo, off, + ptosis, a falling]
Clonal expansion- expansion means become more or grow larger; expand your wealth from $1000 to $1 million. clonal means here a clone is expanded; a clone of B or T cells, namely the clone that recognized the Ag
Not based on beneficial or harmful antigen
These reactions may be triggered by the intrinsic ability of the complement system to recognize microbial components or by Abs bound to the microorganism Ehrlich term for the thermolabile substance, normally present in serum, that is destructive to certain bacteria and other cells sensitized by a specific complement-fixing antibody. Complement is a group of at least 20 distinct serum proteins, the activity of which is affected by a series of interactions resulting in enzymatic cleavages and which can follow one or the other of at least two pathways. In the case of immune hemolysis (classical pathway), the complex comprises nine components (designated C1 through C9) that react in a definite sequence and the activation of which is usually effected by the antigen-antibody complex; only the first seven components are involved in chemotaxis, and only the first four are involved in immune adherence or phagocytosis or are fixed by conglutinins. An alternative pathway (see properdin system) may be activated by factors other than antigen-antibody complexes and involves components other than C1, C4, and C2 in the activation of C3. See Also: component of complement. Origin [L. complementum, that which completes, fr. com-pleo, to fill up] complement pathways heparin complement
Fig 2-1 Cells involved in the immune response
LGL =large granulocyte
Uncommitted cells have no specialized receptor Committed B cells possess a specific receptor that recognizes one and only one EPITOPE of an antigen