Study Guide Sheet 2 (pt1) Flashcards
Define immune response
A 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
What are the general functions of lymph nodes?
Lymphatic fluid containing antigens and Antigen-Presenting Cells flows through lymph nodes where the antigens encounter and activate precommitted lymphocytes
responds to local or regional infections
What are the general functions of the spleen?
Filters blood and traps blood-borne antigens
responds to systemic infections
State the major characteristics of antigens, including the chemical nature and the typical minimal size.
- Substance appears foreign to host’s immune system
- Size – relatively large molecule, molecular weight usually greater than 10,000
- Chemical nature – usually protein with complex 3-D configuration
What is an epitope?
The specific part of the immunogen that specifies or determines the exact antibody to be produced
Define and characterize antibody: specificity
- Anitbody - antigen-specific proteins which bind to specific sites on antigens and assist in inactivating the antigen by attaching to it
What is the chemical makeup of an antibody?
Chemical – glycoproteins (4-18% carbohydrate) produced/secreted by plasma cells
What is the basic shape of an antibody?
“Y” shaped with Fab sites and FC region
What is the specificity of an antibody?
Specificity - a macromolecule consisting of at least one monomer (one basic unit) comprised of two heavy chains and two light chains. Some classes are comprised of more than one monomer.
What is the role of the Fab site?
The role of the fragment antigen binding site, is to actually bind to the epitope of the antigen in a “lock and key” fashion.
How many Fab is/are there on one immunoglobulin molecule?
There are two fab sites per monomeric molecule
Draw and label a detailed illustration of an immunoglobulin structure.
Draw it
What are the major characteristics of and differences between innate and adaptive responses?
Innate is the Non-specific, general recognition and response to “foreign” substances, using physical and chemical barriers.
Adaptive is the Specific response to “foreign” substance using pre-committed cells and tissues
Describe phagocytosis.
When a phagocyte, ingests an antigen or opsonized cell, and uses its lysosomal enzymes to digest it, resulting in debris.
Describe the major histocompatibility complex protein classes, where each is found, and what are their roles?
- MHC 1 is a one chain amino acid protein that about every host cell in the body has. This differentiates “Self” from “non-self”
- MHC 2 is a two chain amino acid molecule that only APC’s carry (macrophages, dendritic cells, and B-cells). This allows them to present the epitope of an antigen to the T helper cells.
What significant surface molecules are on T-cells ?
- CD3 – identifies mature T-cell
- CD28 – receives activation co-signal from CD80/86 molecule on APC
- CD40 – receptor binds with CD-40 molecule on B-cell
- LFA-1 – (Leukocyte Function-associated Antigen-1) – an adhesion molecule on T-cells
What significant surface molecules are on B-cells?
- CD80/86 – when utilized as an APC
- CD40 - significant for binding with certain T-lymphocytes (Th)
- CD19, CD20, CD21 - used for identification
Where do the T-cells mature and where do they concentrate after they mature?
T-cells mature in the thymus, and concentrate to the lymph nodes.
Where do the B-cells mature & concentrate?
B-cells mature from bone marrow and concentrate in peripheral lymphoid tissues, e.g. spleen, mucosal-associated-lymphoid-tissue, lymph nodes, and bone marrow
Define “Antigen-Presenting Cell”
A cell that can present the epitope of an antigen to a helper T-cell
Where are macropahges found, and what significant surface components, and the major roles/activities do they have?
MHC II, presents the epitope of the antigen to the helper T cell
Where are B-cells found, and what significant surface components, and the major roles/activities do they have?
- Found in the spleen, MALT, lymph nodes, and bone marrow.
- CD40, CD19/20/21, CD80/86 and MHC II (as APC)
Where are Dendritic cells found, and what significant surface components, and the major roles/activities do they have?
Numerous MHC II’s.
Alveolar macrophage (lung)
Kupffer cells (liver)
microglial cells (brain)
Langerhans cells (skin)
interdigitating dendritic cells (lymph nodes and spleen most frequent APC)
What are the primary cells involved in cell-mediated immunity response?
- APC (macrophages and dendritic cells)
- T-helper cells
- CTL’s
- NK cells
What are the primary cells involved in humoral immunity?
- APC (Macrophages, dendritic cells, and B-cells)
- T-helper cells
- B-cells to Plasma cells to produce: IgM, IgG
