Term
| What are some nonspecific defenses? |
|
Definition
lipids & pH of skin
mucus
cilia
cough mechanism
inflammation
digestive enzymes |
|
|
Term
| What characterizes the immune response? |
|
Definition
specificity
memory
amplification |
|
|
Term
|
Definition
molecules which evoke an immune response when introduced to a host
-typically proteins |
|
|
Term
| What is the humoral immunity? |
|
Definition
| transformation of B cells into plasma cells |
|
|
Term
| What is the cell-mediated immunity? |
|
Definition
| transformation of T cells into effector 'killer' cells & helper cells |
|
|
Term
| What are B cells? types? function? |
|
Definition
from bone marrow
plasma cells - generate antibodies
memory cells - specific & enhanced immunity |
|
|
Term
|
Definition
CD4+ are 'helper' cells, secrete cytokines
Th3: activate macrophages & B cells
Th2: activate mast cells & eosinophils
CD8+: cytotoxic killer cells |
|
|
Term
| What happens when B cells come in contact with an antigen? |
|
Definition
antibody & antigen form a complex
cause proliferation of B cells
differentiation into plasma & memory |
|
|
Term
| What happens when T cells come in contect with antigens? |
|
Definition
-interact with fragments expressed by phagocytotic cells
-proliferate into CD4 & CD8 cells |
|
|
Term
| What do effector T cells do? |
|
Definition
cause lysis of virus-infecting cells
(these are CD8 cells) |
|
|
Term
| What are the main classes of immunoglobulins? |
|
Definition
IgG: colostrum, memory immune responses
IgA: mucosal
IgM: viruses, bacteria, first immune response
IgE: parasites, bind to Fc receptors on mast cells & eosinophils
IgD: signal activation of B cells |
|
|
Term
| How do B cells make antibodies? |
|
Definition
-naive cell is activated by an antigen
-differentiates into an effector cell
-secrete lots of soluble antibody with the same antigen binding site as the one that stimulated it |
|
|
Term
| What is the role of macrophages in the immune response? |
|
Definition
| phagocytize offending particles & present antigen |
|
|
Term
| Steps of antigen-antibody interactions? |
|
Definition
Aggulitnation: Ag & Ab clump together, cross link
Opsonization: antigen is coated with antibody to increase phagocytosis
Complement fixation: production of proteins which punch moles in cell membranes |
|
|
Term
|
Definition
| compartments for B & T cells which will undergo clonal expansion after being presented antigens by macrophages or dendritic cells |
|
|
Term
| What is the primary immune response? |
|
Definition
-first exposure to an antigen
-clonal expansion of B cells to create plasma cells which secrete antibody, especially IgM |
|
|
Term
| What is the secondary immune response? |
|
Definition
-accelerated response, producing specific antibodies quite rapidly
-primarly IgG |
|
|
Term
| What is active immunization? |
|
Definition
| developing antibodies in response to an antigen, either naturally or induced through vaccination |
|
|
Term
| What are hypersensitivity reactions? |
|
Definition
| an immune response that leads to tissue injury |
|
|
Term
| What are the types of hypersensitivity reactions? |
|
Definition
Type 1: anaphylactic
Type 2: antibody-dependent
Type 3: complex-mediated
Type 4: cell-mediated |
|
|
Term
| What is type 1 hypersensitivity? |
|
Definition
First exposure: B cells produce IgE antibodies
-IgE bind to F receptors on mast cells & eosinophilsm sensitizing them
Second exposure: IgE on mast cells cross links, causing degranulaton & secretion of mediators |
|
|
Term
| What mediators are released in Type 1 hypersensitivity? |
|
Definition
histamine
leukotriene
prostaglandin |
|
|
Term
| What is released during the immediate phase of type 1 hypersensitivity? |
|
Definition
vasoactive amines
lipid mediators |
|
|
Term
| What is released during the late phase response of Type 1 hypersensitivity? |
|
Definition
| eosinophils which release mediators |
|
|
Term
| What effect does histamine have in type 1 hypersensitivity? |
|
Definition
|
|
Term
| Hay fever & asthma are related to what type of hypersensitivity? |
|
Definition
|
|
Term
| What is type 2 hypersensitivity? |
|
Definition
| antibodies produced by the immune response bind to antigens on the patients own cells (some of which are self) |
|
|
Term
| Rh incompatibility is an example of what type of hypersensitivity? |
|
Definition
|
|
Term
| Myasthenia gravis is an example of what type of hypersensitivity |
|
Definition
|
|
Term
| What mechanisms cause Type 2 Hypersensitivity? |
|
Definition
Opsonization of a normal cell surface component
Inflammation in tissues due to activation of the complement system (neutrophils & monocytes recruited)
Anti-body Mediated Cellular Dysfunction |
|
|
Term
| What is Anti-body Mediated Cellular Dysfunction |
|
Definition
| formation of an antibody against a surface molecule or receptor which inhbits/stimulates function without causing necrosis |
|
|
Term
| What is Type 3 hypersensitivity? |
|
Definition
| formation of intravascular immune complexes as a result of antibody-antigen interactions, which are deposited in small vessels & activate the complement system |
|
|
Term
| What happens after the complement system is activated in type 3 hypersensitvitiy? |
|
Definition
| neotrophils are recruited to phagocytize cells, which leads to significant necrosis |
|
|
Term
| What is the end result of immune-complex mediated hypersensitivity> |
|
Definition
|
|
Term
| Local Immune Complex Disease is what type of hypersensitivity? What does it do? |
|
Definition
Type 3
-tissue injury at the site of antigen entry
-repeated exposure to antigen = formation of complexes which are deposited & cause acute vasculitis & tissue necrosis |
|
|
Term
| What is systemic immune complex disease? |
|
Definition
A type 3 hypersensitivity
-large dose of antigen exposure, more than available antibodies, causing formation of small complexes which pass through endothelial pores & are deposited in vessel walls
-activate the complement, lead to tissue necrosis |
|
|
Term
| What is Type IV hypersensitivity? |
|
Definition
CD4+ cells recognize an antigen in a major histocompatibility complex
-secretion of cytokines mediate an immune response by activating macrophages
-CD8 cells will kill cells on contact, forming giant cells |
|
|
Term
| Diabetus mellitus, chrone's disease & poison ivy are examples of what kind of hypersensitivity? |
|
Definition
|
|
Term
| What cells cause necrosis of grafted tissue? |
|
Definition
|
|
Term
| What produces HLA antigens? |
|
Definition
| the major histocompatibility complex |
|
|
Term
| How would DTH lea to classic acute rejection? |
|
Definition
-T cells destroy the parenchyma & endothelial cells of the grafted tissue
-T cells damage graft vasculature
CD8 cells directly kill |
|
|
Term
| Hyperacute rejection occurs when.... |
|
Definition
| preformed antibodies bind to the graft endothelium causing ischemia & thrombosis |
|
|
Term
| What is the defining characteristic of AIDS? |
|
Definition
| loss of CD4+ cells leading to increased susceptibility to pathogens & cancers |
|
|
Term
| What causes a loss of CD4+ cells in AIDS? |
|
Definition
increased destruction of infected cells
reduces production of CD4 cells |
|
|
Term
| What cells are affected by HIV? How? |
|
Definition
monocytes (reservoirs)
macrophages (reservoirs, transportation)
CD4+
Dendritic cells |
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