Immunology Flashcards
(73 cards)
Sequence of related host defense events beginning when a host encounters a substance as being “foreign” or “non-self” and leading to cellular and chemical defensive actions
Immune Response
What are the 8 various blood cells?
Stem cell Erythrocyte Neutrophil Eosinophil Basophil Monocyte Lymphocyte Macrophage
What are the general functions of lymph nodes and the spleen?
Site of some immune response activities
State the major characteristics of antigens, including the chemical nature and the typical minimal size.
Stimulates an immune response and reacts with antibodies or T-cell receptors.
Chemical Nature: Protein with complex 3-D configuration
Size: Relatively large molecule
The specific part of the immunogen (antigen) that specifies or determines the exact antibody to be produced.
Epitope
Antigen- specific proteins which bind to specific sites on antigens and assist in inactivating the antigen by attaching to it.
Antibody
What is the role of the Fab site? How man Fab is/are there on one immunoglobulin molecule?
Antigen specific binding site (lock and key for specific antigens).
2 Fab sites on outer branches
What are the major characteristics of innate responses?
Innate: non specific, general recognition and response to “foreign” substance.
- Route of transmission or portal or entry and type of microbe determine the nature of innate response.
What are the major characteristics of adaptive responses?
Adaptive: Specific response to “foreign” substance.
- Pre committed cells and tissues respond against the ‘foreign’ substance.
What are the differences between innate and adaptive responses?
Innate:
- Non-specific, general recognition and response.
- Rote, portal, or entry and type of microbe determine the nature.
Adaptive:
- Specific response
- Pre committed cells and tissues respond
Describe the Major Histocompatibility Complex (MHC) protein classes, where each is found, and what are their roles?
Class I: (one amino acid chain) found on virtually every cell in body.
Class II: (two amino acid chains) found only on immunocompetent cells, particularly B-cells and macrophages.
What significant surface molecule are on T-cells and what are their roles?
CD3: Mark mature T-cells
CD28: get the activation co-signal from CD80/86 on APC
CD40 receptor: bonds with B-cell on CD40
LFA-1: adhesion molecule on T-cell
What significant surface molecule are on B-cells and what are their roles?
CD40: Bonds with T-cells (CD40 receptor)
CD19,20, and 21: Used for identification
CD80/86: When B-cell acts as APC (binds with T-cells)
Where do the T-cells mature and where do they concentrate after they mature?
They mature in the thymus and concentrate in the lymph nodes
Where do the B-cells mature and where do they concentrate after they mature?
They mature in the bone marrow and concentrate in the peripheral lymphoid tissue
Bind antigens to specific receptors on the APC surface then place some digested antigen on their MHC-II molecule “present” it to the helper T-cells
Antigen-Presenting Cell
State the different types of Antigen-Presenting Cells and where they are found, significant surface components, and the major roles/ activities of APCs.
Macrophages: Capture antigenic material (whole microbes) via phagocytes
-Found: on Ag on MHC-11
B- Lymphocytes: capture “digested” antigenic material via antigen- specific B-Cell receptors (B-cells are not phagocytic)
-Found: On Ag on MHC-II
Dendritic Cells: little to no phagocytic capacity but process numerous MHC-II (good at capturing and presenting antigens)
- Found: Specific tissues initially then migrate
- Role: initiating antigen- specific T-cell responses
What are the primary cells involved in cell-mediated immunity response?
APC
T-lymphocytes (helper and cytotoxic)
Natural Killer
What are the primary cells involved in humoral immunity?
APC
Activated Helper T-lymphocyte
B-lymphocyte
Describe the key composite and activities of helper T-cells.
- Possess CD4 in addition CD3 and surface proteins
- Recognize antigen bound to MHC-II of APC
Describe the key composition and activities of cytotoxic T-cells.
- Posses CD8 and LFA-1
- Requires IL-2 from activated Helper-T for initial CD8 a activation and proliferation
- Destroy target cells by releasing granules containing toxic substances
A proteoglycan which serves to assemble a complex containing granzymes and perforin
Serglycin
A membrane- penetrating protein which creates an entrance into the target cell
Perforin
Cytotoxic protease molecules which cleave various proteins in the target cell’s cytoplasm thus leading to apoptotic death of the target cell
Granzymes
