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23 Cards in this Set
- Front
- Back
What are the three different pathways of the complement system?
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1. Classic pathway- triggered by immune complexes
2. Mannose binding lectin pathway- triggered when this lectin binds mannose groups in bacteria 3. Alternative pathway(properdin)- triggered by contact with various viruses, bacteria fungi and tumor cells. |
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What do complement proteins actually do?
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They help kill invading organisms by opsonization, chemotaxis and eventual lysis of the cells.
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These complement proteins and fragments serve in part as a bridge from innate to acquired immunity by activating B cells and aiding immune memory. TRUE/FALSE
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TRUE. They also help dispose of waste products after apoptosis.
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What are perforins?
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This is involved in cell lysis brought about by complement protein. It is brought about by inserting proteins called perforins.
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What are the three different pathways of the complement system?
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1. Classic pathway- triggered by immune complexes
2. Mannose binding lectin pathway- triggered when this lectin binds mannose groups in bacteria 3. Alternative pathway(properdin)- triggered by contact with various viruses, bacteria fungi and tumor cells. |
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What do complement proteins actually do?
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They help kill invading organisms by opsonization, chemotaxis and eventual lysis of the cells.
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These complement proteins and fragments serve in part as a bridge from innate to acquired immunity by activating B cells and aiding immune memory. TRUE/FALSE
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TRUE. They also help dispose of waste products after apoptosis.
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What are perforins?
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This is involved in cell lysis brought about by complement protein. It is brought about by inserting proteins called perforins.
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Verbally outline the development of the system mediating acquired immunity.
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1. From the bone marrow and lymphocyte precursors are born T lymph. and B lymph.
2. T lymph. mature in the thymus and will become cytotoxic T cells(CD8 T cells) which confirms cellular immunity. These same T lymph, from the thymus will become helper T cells(CD4 T cells) that will help create memory B cells. 3. B lymph will continue development in bone marrow and liver, and will become plasma cells(with the help of Helper T cells). These plasma cells will create and clone immunoglobulins to confer Humoral immunity. |
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The recognition ability is innate and develops without exposure to the antigen. TRUE/FALSE
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TRUE. Stem cells differentiate into many different T and B lymphocytes, each with the ability to respond to a particular antigen.
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What are antigen presenting cells?
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They include specialized cells called dendritic cells in the lymph nodes and spleen and Langherhan cells in the skin.
Macrophages and B cells also can function as APCs. |
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How do APCs basically function?
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In APCs polypeptide products of antigen digestion are coupled to protein products of the MHC complex(MHC) genes genes and presented on the surface of a cell. The products of the MHC genes are called Human Leukocyte Antigen.(HLA)
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What are the two classes of MHC?
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The genes of the MHC, which are located on the short arm of human chromosome 6, encode glycoproteins and are divided into 2 classes on the basis of structure and function.
Class 1 are found on all nucleated cells. Class 11 are heterodimers. They are present in APCs, including B cells and in activated T cells. |
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The class 1 MHC proteins are coupled promarily to peptide fragments generated from proteins synthesized within cells. TRUE/FALSE
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TRUE. Nontolerant peptides, those from mutant or viral proteins, are recognized by T cells. The digestion of these proteins occur in proteasomes(protealytic enzymes) in the MHC group, and the peptide fragments appear to bind to MHC proteins in the endoplasmic reticulum.
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How does this compare to the class 11 proteins?
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These are concerned primarily with peptide products of extracellular antigens, such as bacteria, that enter the cell via endocytosis and are digested in the late endosomes.
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Receptors on T cells must recognize a wide variety of complexes. TRUE/FALSE
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TRUE. Most of the receptors on circulating T cells are made up of two polypeptide units designated a/B(alpha and beta).
They form heterodimers that recognize the MHC proteins and the antigen fragments with which they are combined. These are called a/b T cells. |
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Are these a/b T cells the only T cell receptors?
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No. About 10% of the circulating T cells have 2 different polypeptides designated gamma and theta in their receptors(g/t T cells). They are prominent in the GI tract.
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CD8 occurs on the surface of cytotoxic T cells that bind MHC-1 proteins, and CD4 occurs on the surface of helper T cells that bind MHC-11 proteins. TRUE/FALSE
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TRUE.
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What is immunologic synapse?
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The T cell receptors are surrounded by adhesion molecules and proteins that bind to complementary proteins in the APC when the 2 cells transiently join to form the immunological synapse, that permits T cell activation to occur.
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B cells can bind antigens directly, but they must contact helper T cells to produce full activation and antibody formation. TRUE/FALSE
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TRUE. Infacct, it is the TH2 subtype that is mainly involved. helper T cells are pushed along the TH2 line by the cytokine IL-4.
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What does IL-12 do?
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It pushes helper T cells along the TH-1 line.
IL-2 acts as an autocrine fashion to cause activated T cells to proliferate. |
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What are monoclonal antibodies?
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Large quantities of the immunoglobin produced by a single plasma cell can be obtained by fusing the cell with a tumor cell, producing an antibody factory.
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How are monoclonal antibodies obtained?
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Animals are immunized with a particular antigen or cell preparation. The antibody producing cells are extracted from their spleens and fused to myeloma cells.
Myelomas are B lymphocyte tumors that readily fuse with plasma cells to form antibody forming hybridomas, which grow and produce very well. the fused cells are separated and each starts a clone of cells descended from a single cell. |