Phagocytes
Types
T Reg
Inhibits immature dendritic cells
TFH
Help isotype switching of B cells
CD4 TH17
Enhance neutrophil response. Promote barrier integrity
CD4 TH2
Parasitic and allergies. Helps B cells produce antibodies
CD4 TH1
Activate infected macrophages and help B cells in antibody production
CD8 Cytotoxic T cells
Kill virally infected cells
Ways to Activate
IL-2
CD8 to proliferate
CD4 T Cell
APC
B7 and IL-2 to activate CD8 T Cell
B7 activates CD8 T Cell
Generation of Diversity
T-Cell Development
Beta chain
2 on each chromosome
Alpha Chain
DN4 to DP
Rearrange multiple times
DN2
pTalpha
Checks functionality of receptor
B-Cell Development
Heavy chain
Large pre-B
Is chain funtional?
2 (4 if counting DJ and VD separately
2 Rearrangements
Light chain
Immature B
Do light and heavy chain produce functional binding site?
Many rearrangements
Small pre-B cell stage
Lambda 5, VproB
Bone marrow
Early pre-B to large pre-B cell stage
CD4 T Cells
Complement Cascade
Alternative
C3b (from other pathways)
C3bBb3b
C3bBb
Classical
C4b2a3b
C1
Lectin
C4b2a
Manose Binding Lectin
Direct lysis of pathogen
Opsonization
Coating of a pathogen by antibodies so phagocytic cells can destroy it
Recruitment
Antibodies
bind to antigen and remove it
Dendritic Cells
T-Lymphocyte
Clonal Selection Theory
Clones
Enters Circulation
Long-lived memory cells
Short-lived effector cells
Lymphoid Tissues
T Cell Trafficking
Diapedesis
CCL21 and CXL12
Adhesion
Integrins
LFA-1
Chemokines
CCL21
Rolling
Selectins
L-selectin
Activation of T Cell
Processes MHC II
CD40L: CD40
Anergent
CD28: B7
IL2 binds to IL-2R
Proliferate
Secondary Lymphoid Tissue
Activates macrophages and Dendritics
Inflammatory Response
Cytotoxic T Cells
Helper T Cells
Memory Cells
APCs
Clonal Expansion of Naive T Cells
Differentiation
Cytokines tell cell what to turn into
Survival
CD28-B7
Activation
MHC to TCR
Macrophages
Antigen
Natural Killer Cells
B-Lymphocyte
Surface
Activation of B cell
T cell
CD40 Ligand
Cytokines IL-4, IL-5, and IL-6
Affinity Maturation
Positively selected B cell
Negatively selected B cell
Apoptosis
affinity for antigen
T cell Help
B cell cross linking
Memory cell
Germinal Center
Centrocytes
Centroblasts
Isotype Switching
T Cells
Somatic Hypermutation
Point Mutations
Selection
Plasma Cell
Memory Cell
MHC II
MHC I
Anchor Residues
Which peptides bound to MHC
alpha-2
Size Restriction
8-10 Amino Acids
More than 10 amino acids
Length Unrestricted
beta-1
alpha-1
CR2
B cell
CD40
CD3
antigen
Cross-link Antigen
Plasma Cells
Bone marrow stem cells
Immune Responses
Innate Immunity
Pathogen Recognition
Receptors (PRR)
4 different types
and functions
Cytoplasmic signaling
receptors
Lysis, opsonization,
inflammation
Membrane bound
signaling receptors
Stimulate phagocytosis
Membrane bound
phagocytic receptors
Sense potential pathogens
and initiate inflammatory response
Free receptors in
serum
Sense intracellular pathogens and
initiate inflammatory response
Inflammation
Tumor
Fluid enters site to attack pathogen
Dolor
Foreign invader notice
Rubor
More cells into area of need
Calor
Increased heat up regulates immune response
Generalized/ Nonspecific
Response to wide array of antigens
Adaptive Immunity
Selection Process
T Cell Development
MHC present self antigen
Any in thymus, DCs, macrophages
Throughout thymus, mostly corticomedullary junction and medulla
Recognize self MHC
Lives
Dies
No receptor editing
Thymic Epithelial Cells
Thymus
Cortex
Double Positive
B Cell Development
Negative Selection
If responds to self cells: either apoptosis
Receptor Editing!
Any in bone marrow
Bone Marrow
B cells that bind soluble antigens within bone marrow
Immature B Cell
Positive Selection
No Receptor Editing
FDC's
Positive life signal, otherwise die in 3 days
Secondary Lymphoid Organ
B Cell Follicle
Immature to Mature B Cell
Checks that receptors don't become activated due to presence of self
Lymphocytes
