Exam 4 Flashcards
Cytotoxic T cells express what?
CD8 to recognize MHC 1 proteins on infected cell
How do cytotoxic T cells act?
they kill antigen-bearing target cells direclty
What do T-helper cells express?
CD4 to recognize MHC 2 protein on infected cell
How do T-helper cells act?
they act through cytokines to promote immune reactions
Cytokines signal what?
B-cells
What are the two subclasses of T-helper cells?
T-helper 1
T-helper 2
Which T-helper cell is less specific?
T-helper 1
How do T-helper 1 cells work?
they attract and activate macrophages for non-specific cellular defense
initiate inflammation
How do T-helper 2 cells work?
stimulate B-cells to produce antibodies
very specific
How do natural killer cells work?
they have no memory but recognize any foreign cells and kill the entire cell
Natural killer cells are an effective defense against what cells?
cancer and virus infected cells
What cells make antibodies?
B-cells
Where are antibodies found?
serum, milk, and gastric secretions
How do B-cells work?
antibodies on cell surface interacts with antigens & B-cell uses phagocytosis to ingest pathogen
Antibodies are also known as what?
immunoglobulins
What is the structure of antibodies?
two heavy chains
two light chains
What fragments of antibodies can bind antigens?
Fab fragments (top 2 parts of the Y shaped antibody)
What fragments of antibodies cannot bind antigens?
Fc fragment (bottom stem of the Y shaped antibody)
What is the protease that digests the antibody into its 3 fragments?
papain
What part of the Fab fragment on an antibody actually binds the antigen?
variable region
it varies from antibody to antibody
What are the 5 types of antibodies?
IgG
IgM
IgA
IgE
IgD
Which type of antibody is found in secretions from mucous membranes?
IgA
Which types of antibodies are found in blood?
IgG and IgM
Which type of antibody is found in serum & is involved in parasite immunity & allergies?
IgE
Which type of antibody is found on the surface of B-cells?
IgD