dna vaccine induces th1 response
TRANSCRIPT
DNA vaccine induces TH1 response.
CpG
plasmid
APC
TLR9 IL12 TH1
CTL
IgG2a
B cell
DNA vaccine is preferred for inducing immunity against intracellular infection.
pXL2 (RSV DNA vaccine): TH1 responsepXL0 (control)
Live RSV vaccine: balanced TH1/TH2
Formalin inactivated RSV: TH2 response
DNA vaccine expressing multiple antigens
DNA vaccine priming / boosting with other vaccines
Mucosal vaccine
Mucosal surface is the major site of pathogen entry.
Mucosal vaccine induces both mucosal and systemic immunity.Injected vaccines are poor inducers of mucosal immunity.
DC
M
B
GCT T
Plasma cells, memory B cells TH cells, CTL
Mucosal lymphocytes home to mucosal tissues.
Peyer’s patch
Plasma cells, CTL, TH cellsMemory cells
Lymph node
Blood circulation Blood circulation
Other mucosal tissuesOther mucosal tissues
Inductive site
Effector siteEffector site
Common mucosal immune system
Lymphocyte homing to mucosal tissueMucosal tissue-specific adhesion molecules and chemokine/chemokine receptors
plasma cells
CCR10 CCL28
Epithelial cellsof intestine andother mucosal tissues
47 integrin
Endothelial cells of venules in intestine
MADCAM1 (addressin)
CCR9 CCL25
Epithelial cellsof intestine andother mucosal tissues
47 integrin
Endothelial cells of venules in intestine
MADCAM1 (addressin)
Effector T cells
Mucosal induction site
Mucosal effector site
Mucosal immunization also induces systemic immunity.
DC
M
B
GCT T
Mucosal lymphoid tissue
Lymph node
Systemic immunity
Mucosal immunity
Mucosal plasma cells produce IgA.
Epithelial cells
Mucus Dimeric IgA Neutralization
IgA+
Mucosal plasma cells IgG
Systemic immunity(lymph nodes, spleen)
Blood circulation
Blood circulationMucosal effectorT and B cells
CTL
TH
IgA > IgG
IgG > IgA
Preferential localization of mucosal immunityto induction site
Challenges in mucosal vaccine
Degradation, dilution on mucosal surface
Live attenuated pathogen (polio vaccine, S. typhi vaccine)
Use as recombinant vectors vaccines
Prevent tolerance
Mucosal adjuvant to induce “danger signal” (activate DCs)
Mutated enterotoxins of bacteria (e.g. cholera toxin)
PAMPs (e.g. CpG, flagellin)
Immune response against tumor
Tumor cells Tumor Ag
Uptake of Tumor AgBy immature DCs
Mature DCsMHC I and II-antigen
B7
CD4 T
CD8T
CTL
CTL
Kill tumor cells
Lymph node
Cancer vaccine
Boosting Immune response against tumor
Tumor cellsTumor Ag
Uptake of Tumor AgBy immature DCs
Mature DCsMHC I and II-antigen
B7
CD4 T
CD8T
CTL
CTL
Kill tumor cells
Lymph node
Immunization with Tumor Ag
Loading DCs with Tumor Ag (DC vaccine)
In vitro activation of anti-tumor T cellsAdoptive transfer
Cytokine stimulation
Dendritic cell vaccine
patient
monocytes
Immature DCs
CD34+ HSCDirect isolation
Mature DCs
Cytokines
DC loaded with tumor Ag
Peptides or proteins (tumor Ag)
Tumor cell lysate
cytokinescytokines
Cancer vaccine trials
Peptide vaccines alone or with IL-12 or GM-CSF
Recombinant virus expressing tumor antigens
Irradiated autologous tumor cells or tumor cell lysates
Dendritic cells loaded with peptides, proteins, or tumor lysates, etc.
Immunosuppression mechanisms of tumor
HSC
Inhibition of DC maturation
CMP iMC
Immature Myeloid cells
myeloid DCs
M
granulocyte
Immature DC
activation
Mature DCBone marrow
Peripheral tissues
Immature DCs capture antigens.
Mature DCs activate T cells.
Immature DC Mature DC
MHC II-
B7-
MHC I+ MHC I+
MHC II+
B7+ Antigen capture Antigen presentation
CD4 T
CD8 T
TH
CTL
2o lymphoid tissues
T cell toleranceT cell activation
Tumors inhibit DC maturation.
Immature DC Mature DC
MHC II-
B7-
MHC I+MHC I+
MHC II+
B7+
Tumor cells
VEGF
M-CSF IL6
Cyclooxygenase-2 (COX2) produces prostaglandin E2, PGE2)
VEGF (vascular endothelial growth factor)
M-CSF (macrophage colony-stimulating factor)
PGE2
IL10
TGF-
gangliosides
Tumor microenvironment
Reduced number of DCs in cancer patientsClinical Cancer Research 6, 1755-1766 (2000)
HNSCC: head and neck cancer
Defective DC function in cancer patients
DCs (mismatched class II MHC) CD4 T cells Proliferation (3H incorporation)
Cancer patients have higher proportions of Immature DCs.
Immature DCs: HLA-DR- (class II MHC)
B7-
CD40-
Surgery removal of tumor reduces immature DCs.
5 patients
Proportion of immature DCs
Reduction of immature DCs after chemotherapy and Anti-VEGF antibody treatment.
Tumors induce the expression of B7-H1, H4 in APCs.
Normal maturation
B7.1(CD80), B7.2(CD86)
T cell activation
B7-H1, H4
Tumor microenvironment
B7-H1, B7-H4 inhibit T cell activation (co-inhibitory molecules)
Some tumor cells express B7-H1,B7-H4.
B7-H1,B7-H4
CD4+CD25+FoxP3+ T cells (5-10% of peripheral CD4 T cells)
Cancer patients have higher levels of Treg cells.
Inhibit T cell response.
Depletion of CD25+ cells increases tumor rejection.
Depletion of Treg cells by DAB389IL-2 (denileukin diftitox, ONTAK)
High affinity IL2 receptor
IL2R: CD25
Low affinity IL2 receptor
Naive T cellEffector T cellCD4+CD25+Treg
CD25+ T cell
IL2Diphtheria toxin
DAB389IL-2
CD25- T cell
DAB389IL-2 preferentially kill CD25+ T cells.
DAB preferentially kills CD25high Treg cells.
CD4+CD25neg
CD4+CD25int
CD4+CD25highCD4+CD25neg T cells: naïve resting T cells
CD4+CD25int T cells: activated T cells
CD4+CD25high T cells: Treg cells (FoxP3+)
J. Clinical Investigation 115, 3623-3633 (2005)
RCC: Renal cell carcinoma
Donor: healthy control
Cancer patients have highly levels of CD25+Treg cells(FoxP3+)
Depletion of CD25+Treg cells enhances T cell response against tumor.
patient Vaccinated with DC vaccineagainst RCC
Determine the frequency of CD8+ T cellsthat express IFN- in response to tumor.
Patient Treat with DAB
Treatment with CTLA4-specific antibodyCD4+CD25+Treg cells constitutively express CTLA4.
CTLA4 antibodies improve tumor rejection, but cause autoimmunity.
Adoptive transfer of anti-tumor T cellsScience 298, 850-854 (2002)
13 Cancer Patients
(metastatic melanoma)
Melanoma
Tumor cells
TIL(tumor infiltrating
Lymphocyte)
Expansion of TIL in cell culture
Anti-CD3+IL2
These T cells can be activatedBy tumor antigens in self-MHC
Lymphodepleted patients
Cyclophosphamidefludarabine
Infusion of anti-tumor T cell with IL2
6/13 responded5/13 have autoimmune melanocyte destruction
Tumor regression after a few month
Relevant part in book
Cancer vaccine and therapy: page 511-520