Types of Joints and Bursae Ana Soldo 2013/2014 Zagreb Medical School Mentor: A. Žmegač Horvat.
Maja Marković, 2nd year, 2013/2014 Mentor: A. Žmegač Horvat.
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Transcript of Maja Marković, 2nd year, 2013/2014 Mentor: A. Žmegač Horvat.
Maja Marković, 2nd year,2013/2014
Mentor: A. Žmegač Horvat
Antigen word origin: antibody generator /
anti(body)-gen
= any substance foreign to the body that evokes an immune response
parts of bacteria, viruses, parasites, foods, venoms, blood components, and cells and tissues of various species, including other humans
epitope - a molecular region on the surface of an antigen capable of eliciting an immune response and combining with a specific antibody
antigen ≠ immunogen
hapten - a small molecule that can elicit an immune response only when attached to a large carrier such as a protein
urushiol → quinone (reacts with skin proteins)hydralazine (blood pressure-lowering drug) → drug-induced lupus
erythematosus halothane (anesthetic gas) → hepatitispenicillin-class drugs → autoimmune hemolytic anemia
allergens
= antigens which produce an abnormally vigorous immune response to a perceived threat that would otherwise be harmless to the body
superantigens (SAg)
produced by pathogenic microbes as a defense mechanism against the immune system
cause non-specific activation of T-cells → polyclonal T cell activation and massive cytokine release (interferon gamma → macrophages → proinflammarory cytokines IL-1, IL-6, TNF-alpha)
antigen-induced T-cell response: 0.0001 - 0.001% → 25 %
shock and multiple organ failure
tumor antigens
presented by MHC I or MHC II molecules on the surface of tumor cells
tumor-specific antigens (TSAs) - presented only by tumor cells
tumor-associated antigens (TAAs) - presented by tumor cells and normal cells
cytotoxic T lymphocytes may be able to destroy tumor cells before they proliferate, B-cells recognize mutated cell receptors
used as tumor markers (alphafetoprotein, carcinoembryonic antigen CA-125, MUC-1, epithelial tumor antigen ) and vaccines
Antibodieslarge glycoproteins, part of the
immunoglobulin superfamily produced by plasma cells soluble or membrane-bound basic structure: "Y"-shaped molecule two identical heavy chains (α, ε, γ, δ, and μ,
define the class) two identical light chains (λ and κ) connected
by disulfide bonds constant and variable regions
Fab region - antigen-bindingparatope - at the amino terminal end of the
antibody, variable domains from the heavy and light chains
FV region, variable loops of β-strands, three each on VL and VH
Fc region - ensures that each antibody generates an appropriate immune response for a given antigen (recognition of opsonized particles, lysis of cells, and degranulation of mast cells, basophils and eosinophils)
more than 350 types of molecules
markers on the cell surface
critical in antigen recognition (CD4, CD8)
cell surface receptors for growth factors (CD135)
MHC molecules = major histocompatibility complex (human
leukocyte antigen, HLA) a set of cel-surface molecules encoded by a
large gene family in all vertebrates
MHC-I: all nucleated cells; cytotoxic T lymphocyteMHC-II: dendritic cells, mononuclear phagocytes, B lymphocytes, some endothelial cells, epithelium of thymus; helper T
lymphocytes
MHC determines compatibility of donors for organ transplant and one's susceptibility to an autoimmune disease via crossreacting immunization
SourcesTaradi, Milan: Imunologija, 7. dopunjeno
izdanje, 2010.http://www.merriam-webster.com/http://en.wikipedia.org/wiki/Antigenhttp://en.wikipedia.org/wiki/Antibody