Lecture 11 Active immunity Flashcards
immunity based on antibody activity
humoral
immunity based on specific T cells
cellular immunity
what are the APCS
B cells
macrophages
dendritic cells
what can B cells differentiate into when activated?
memory cells
plasma cells
types of T cells
helper T cells
CTLs
Regulatory t cells
how do we differentiate CTL and Helper T cells
CD4– T helper
CD8 – CTL
how do cytotoxic T cells remove infected cells
kill them with perforin pathway
and apoptotic pathway
Class 1 MHC found on
every nucleated cell
Class II MHC
only on APCs
what type of cells do NK cells get rid of?
tumor cells, virally infected cells, and attack parasites
cells that don’t express MHC class I
what all interact with antigen?
MHC (co receptor)
TCR
TCR
reside in the plasma membrane surface
recognize and bind fragment antigens
act as a bridge
Superantigens
bacterial and viral proteins express
stimulate T cells to proliferate nonspecifically
creates a bridge
B cell activation
leads to proliferation and differentiation into plasma cells (Abs) and memory cells
antigen specific
two mechanisms for b cell activation
t dependent
t independent
what type of molecules stimulate T independent
large antigens non proteins (worms)
what do antibodies do
Neutralization Opsinization Complement fixation Agglutination Ab-dependent cell-mediated cytotoxicity
regions of Abs
constant and variable region
variable region makes up
antigen binding site
which part of the Ab does the Ag bind to
Fv (NOT Fc)
class switching
change in antibody class secreted by plasma cells under the influence of T helper cells
unfolds over time
primary response
some time passes but after b cell differentiation into plasma cells, Ab is secreted
first IgM then IgG
even though Ab titer decrease, what happens to cells
activation of memory cells that proliferate to create a secondary response
secondary response
second exposure
greater memory, faster
shorter lag phase, longer persistence
