6.2 Antigen Antibody Lec 6 Flashcards
B cell Adaptive immunity utilizes what to recognize antigen?
surface antibody (immunoglobulin) *THOSANDS of immunoglobulins on each B-cell
B cell can directly bind antigen
in its? why is this important
native configuration (NO processing required) **so it can bind back and react to the SAME antigen
What is required for B cell adaptive immunity to recognize antiegn?
both the sequence of amino acids and the three dimensional configuration of the antigen are required
ANTIGENS have a three dimensional structure
primary structure
secondary structure
tertiary structure
primary structure
Sequence of amino acids-1 or 2 dimensional
secondary structure
Biochemistry of the stretch of amino acids determines secondary structure
*beta sheets AND alpha helixe
tertiary structure
Association of all of the patterns determines final conformation
T cell Adaptive immunity utilizes what to recognize antigen?
utilizes a T Cell Receptor (TCR) for to recognize antigen
TCR cannot bind _____ antigen? T-cells require that?
native (unlike B-cell)
*T-cells require that the antigen be processed with histocompatibility molecules and presented by antigen presenting cell
for TCR to work, antigens must first be?
processed and presented by antigen presenting cells
TCR can only “see” an antigens peptide IF?
peptide of antigen is bound with histocompatibility molecules
what are antigen presenting cells for CD4+ T cells?
macrophages, dendritic cells, and even B cells (breaks antigen down to about 8 AA long)
what are antigen presenting cells for CD8+ T cells?
could be any cell infected by a virus or a cell that develops a mutation
*can also be macrophages, dendritic cells, and even B cells (just same as CD4+)
Besides protein, what other molecuels could be antigens?
- Carbohydrates and polysaccharides
- –a. lipopolysaccharide
- –b. capsular dextran - Lipids
- Nucleic acids
Carbohydrates and polysaccharides as antigen usually induce?
a. lipopolysaccharide- usually induce IgM
b. capsular dextran- usually induce IgM
.Lipid antigens from mycobacteria have their own specific?
T cell iimmune response!
***by CD1 molecules on APCs
Nucleic acids as antigens are associated with?
immune response to these is associated with autoimmune disease
what fraction of blood contains antibody in myeloma patients?
gamma globulin fraction of blood contains antibody
gamma globulins originally found in?
serum of patients with plasma cell cancer (myeloma)
Gamma globulins can be separated from rest of blood proteins by ?
electrophoresis
Gamma globulin fraction is large in _____ serum? This is how we got
myeloma serum
- but not in healthy ppl
- *how we got IgG
why must proteins be stored properly?
if not, they may become denatured. Then you’ll have immune response to unraveled protein… remember you NEED the 3D shape and AA sequence in order to make antibodies that recognize real antigen (aka native protein)
antigens in MHC class 1 histocompatibility are bound where?
in the center flanked by alpha helixs
*thousand fold decrease in AA for antibody’s to recognize
antibody response are SUPER SPECIFIC MEANING?
antigen only needs to change one AA for the antibody to no longer recognize it
what does papain do?
breaks down immunological molecule into 3 framents
*two of which bind antigen
what are the papain fractions that attach antibodies called?
Fab
what is the 3rd papain fraction that is crystalizable?
Fc
what was used to degrade the Fc fraction of pepain?
pepsin
what is fab2 or fab’ ?
compare this to how you got fab
a single molecule that binds two copies of an antigen when pepsin is broken down
*SO pepsin= fab2 and degraded Fc
pepain= 2 fab fractions and whole Fc
