Transcript Foundations of Immunology (Bio 5051)

BIO 5051
Foundations in Immunology
Signaling in lymphocytes
(transcription factors)
November 04, 2005
Robert H. Arch
[email protected]
phone 747-4681
Inflammation
• response to?microbial infections and tissue injury
• local features include? upregulation of adhesion
molecules and enzymes, increased blood flow,
and phagocytosis of debris and dead cells
as well as tissue repair by cell proliferation
• systemic features include? fever and acute phase
response
• mediated and resolved by? a large array of
soluble factors, cell surface molecules, and
enzymes
2003 0390
Inflammation
• response to infections, allergens and tissue injury
• local features include? upregulation of adhesion
molecules and enzymes, increased blood flow,
and phagocytosis of debris and dead cells
as well as tissue repair by cell proliferation
• systemic features include? acute phase response
and fever
• mediated and resolved by? a large array of
soluble factors, cell surface molecules, and
enzymes
2003 0390
Inflammation
• response to infections, allergens and tissue injury
• local features include upregulation of adhesion
molecules and enzymes, increased blood flow,
and phagocytosis of debris and dead cells
as well as tissue repair by cell proliferation
• systemic features include? acute phase response
and fever
• mediated and resolved by? a large array of
soluble factors, cell surface molecules, and
enzymes
2003 0390
Inflammation
• response to infections, allergens and tissue injury
• local features include upregulation of adhesion
molecules and enzymes, increased blood flow,
and phagocytosis of debris and dead cells
as well as tissue repair by cell proliferation
• systemic features include acute phase response
and fever
• mediated and resolved by? a large array of
soluble factors, cell surface molecules, and
enzymes
2003 0390
Inflammation
• response to infections, allergens and tissue injury
• local features include upregulation of adhesion
molecules and enzymes, increased blood flow,
and phagocytosis of debris and dead cells
as well as tissue repair by cell proliferation
• systemic features include acute phase response
and fever
• mediated and resolved by a large array of soluble
factors, cell surface molecules and enzymes
2003 0390
Glucocorticoids activate transcription
of anti-inflammatory genes
dexamethasone
cortisol,
hydrocortisone
HSP-90
HSP-90
Adcock et al. (2004). Proc. Am. Thorac. Soc. 1:247-54
2005 0536
Acetylation of core histones regulates
gene repression and transcription
Adcock et al. (2004). Proc. Am. Thorac. Soc. 1:247-54
2005 0533
Glucocorticoids inhibit transcription
of pro-inflammatory genes
Adcock et al. (2004). Proc. Am. Thorac. Soc. 1:247-54
2005 0535
Transcription factors
of the immune system
•
•
•
•
•
GR
NF-kB
NFAT
AP-1
STAT
glucocorticoid receptor
nuclear factor kappa B
nuclear factor of activated T cells
activating protein-1
signal transducer and activator
of transcription
• GATA-3 (A/T)GATA(A/G) consensus binding motif
• T-bet
T box expressed in T cells
• p53
tumor suppressor p53
• Smad
Sma/Mad (C. elegans/Drosophila)
2003 0349
Transcription factors
of the immune system
•
•
•
•
•
GR
NF-kB
NFAT
AP-1
STAT
glucocorticoid receptor
nuclear factor kappa B
nuclear factor of activated T cells
activating protein-1
signal transducer and activator
of transcription
• GATA-3 (A/T)GATA(A/G) consensus binding motif
• T-bet
T box expressed in T cells
• p53
tumor suppressor p53
• Smad
Sma/Mad (C. elegans/Drosophila)
2003 0349
Nuclear factor kappa B (NF-kB)
• first described as a nuclear factor in B cells that
binds to a 10 bp region of the k intronic enhancer
and is pivotal for Ig k light chain transcription
• can be found in the cytoplasm of most cell types
• family of dimeric transcription factors
• monomers have 300 aa Rel homology region
required for dimerization, DNA binding, and
interaction with inhibitor proteins (IkB)
• release from IkB results in nuclear translocation
2003 0357
•
•
•
•
•
Li and Verma (2002), Nature Rev. Immunol. 2:725-34
RHD: Rel-homology domain
TD: transactivation domain
N:
nuclear localization signal
LZ: leucine zipper
GRR: glycine-rich region
ANK: ankyrin repeats
transcriptionally active:
p65/p50, p65/p65, p50/c-Rel
transcriptionally inactive:
p50/p50, p52/p52
p100/p52 and l05/p50 are
precursors
processing (signal-dependent and
-independent pathways?) is ATPdependent, requires polyubiquitination of IkB, and can be
blocked by proteasome inhibitors
2003 0379
•
•
•
•
•
Chen et al. (1998), Nature 391:410-3
RHD: Rel-homology domain
TD: transactivation domain
N:
nuclear localization signal
LZ: leucine zipper
GRR: glycine-rich region
ANK: ankyrin repeats
transcriptionally active:
p65/p50, p65/p65, p50/c-Rel
transcriptionally inactive:
p50/p50, p52/p52
p100/p52 and l05/p50 are
precursors
processing (signal-dependent and
-independent pathways?) is ATPdependent, requires polyubiquitination of IkB, and can be
blocked by proteasome inhibitors
2003 0379
•
•
•
•
•
Li and Verma (2002), Nature Rev. Immunol. 2:725-34
RHD: Rel-homology domain
TD: transactivation domain
N:
nuclear localization signal
LZ: leucine zipper
GRR: glycine-rich region
ANK: ankyrin repeats
transcriptionally active:
p65/p50, p65/p65, p50/c-Rel
transcriptionally inactive:
p50/p50, p52/p52
p100/p52 and l05/p50 are
precursors
processing (signal-dependent and
-independent pathways?) is ATPdependent, requires polyubiquitination of IkB, and can be
blocked by proteasome inhibitors
2003 0379
NF-kB inhibitors (IkB)
• IkBa, IkBb, IkBg, IkBd, IkBe, Bcl-3
• central ankyrin repeat mediate interaction with
rel-homology domains of NF-kB proteins
• N-terminal domain is phosphorylated in
response to NF-kB activating signals
• phosphorylation of two conserved Ser residues
is required for ubiquitylation and degradation
• C-terminal PEST domain involved in basal
turnover
2003 0384
Yilmaz et al., (2003) EMBO J. Vol 22:121-30
NF-kB activation by LTbR vs. TNFR-I
2003 267
NF-kB-regulated genes
adhesion molecules
enzymes
intercellular adhesion molecule-1 (ICAM-1)
vascular cell adhesion molecule-1 (VCAM-1)
E-selectin
inducible nitric oxide synthase (iNOS)
cyclooxygenase-2 (COX-2)
cytosolic phospholipase A2
5-lipidoxygenase (5-LOX)
cytokines
tumor necrosis factor a (TNF-a)
interleukin-1b
interleukin-6
interleukin-11
granulocyte-macrophage colony stimulating factor
(GMCSF)
anti-apoptotic proteins
chemokines
NF-kB and IkB family members
interleukin-8
CCL3 (macrophage inflammatory protein (MIP)-1a )
CCL7 (monocyte chemotactic protein (MCP)-3)
CCL5 (RANTES)
CCL11 (eotaxin)
TNFR-associated factors (TRAF) 1 and
TRAF2
cellular inhibitor of apoptosis (c-IAP) 1 and
c-IAP2
bcl-2 homologues AI/Bfl-1 and bcl-xL
IkBa
NF-kB1 (p105/p50)
NF-kB2 (p100/p52)
RelB
2003 0358
A central role for ubiquitin
in multiple signalling pathways
CYLD
Chen (2005). Nature Cell Biol. 7:758-65
A20
2005 0532
The NF-kB signalling pathways
TNFRs
canonical
IL-1R, TLR
BAFF-R, LTbR, CD40
non-canonical
modified from Chen (2005).
Nature Cell Biol. 7:758-65
2005 0531
ikka-/- and ikkb-/• ikka-/- mice die post-natally due to multiple
morphological defects; shiny taut skin prevents
emergence of fore- and hind-limbs, absence of
ears, truncation of head, skeletal abnormalities
• ikkb-/- mice die between E12.5 and E14.5 as a
result of fetal hepatocyte apoptosis; embryonic
lethality is rescued by crossing with TNFR-I-/and TNF-a-/- animals
IKKa
-/-
Hu et al. (1999), Science 284:316
2003 0350
IKKa
-/-
Hu et al. (1999), Science 284:316
2003 0350
IKKb
-/-
Li et al. (1999), J. Exp. Med. 189:1839
2003 0351
Li and Verma (2002), Nature Reviews 2:725
2002 006
ikba-/• normal embryonic development, but mice die
7-10 days post-natally due to severe widespread
dermatitis and granulocytosis (delayed in DKO)
• increased expression of distinct pro-inflammatory
cytokines and factors associated with granulocyte
recruitment, such as TNF-a, G-CSF and VCAM
• not all genes induced by NF-kB are upregulated
rela-/• embryonic lethality between E15 and E16 due to
fetal hepatocyte apoptosis induced by TNF-a
• embryonic lethality can be rescued by crossing
with TNFR-I-/- and TNF-a-/- animals
• reconstitution of SCID mice with fetal hepatocytes
revealed defects in mitogen-induced proliferation
and isotype switching but normal lymphopoiesis
Doi et al. (1997), J. Exp. Med. 185:953
rela-/• embryonic lethality between E15 and E16 due to
fetal hepatocyte apoptosis induced by TNF-a
• embryonic lethality can be rescued by crossing
with TNFR-I-/- and TNF-a-/- animals
• reconstitution of SCID mice with fetal hepatocytes
revealed defects in mitogen-induced proliferation
and isotype switching but normal lymphopoiesis
p50-/- (NFKB1-/-)
• despite nearly ubiquitous expression and its role as
major partner of p65 (Rel A), which is essential for
embryogenesis, surprisingly normal development
• although not essential for hematopoiesis, multiple
defects in functions of immune system
Histone acetylation regulates
NF-kB-induced transcription
Adcock et al. (2004). Proc. Am. Thorac. Soc. 1:247-54
2005 0534
Activating protein 1 (AP-1)
•
•
•
•
family of dimeric transcription factors
expressed at low levels
usually constitutively bound to their DNA sites
rapid changes of complex composition upon
stimulation of cells due to de novo synthesis
• phosphorylation by MAPK, e.g., c-Jun Nterminal kinase (JNK), strongly enhances
transactivating capacity
• play crucial roles in cell proliferation, apoptosis
and oncogenesis
2003 0355
Signals leading to
IL-2 expression in CD4+ cells
Foletta et al (1998) J. Leukoc. Biol. 63:139.
2004 0474
Interactions between AP-1 proteins
and other transcription factors
Foletta et al (1998) J. Leukoc. Biol. 63:139.
2004 0475
Co-operative DNA binding
of NFAT and AP-1 proteins
Monomeric NFAT and heterotrimeric
AP-1 transcription factors have
low affinity for their respective
binding sites. Interactions between
NFAT and AP1 stabilize the
NFAT-AP1-DNA complex.
Fig 11.24 Lodish et al. Molecular Cell Biology
2004 0471
Nuclear factor of activated T cells
(NFAT)
• first identified in T cells as rapidly inducible
nuclear factor binding to the IL-2 promoter
• family of transcription factors related to NF-kB
• expressed in most cells of the immune system,
including lymphocytes, mast cells, basophils,
NK cells and endothelial cells
• target genes include cytokines, cell surface
receptors, signaling proteins and transcription
factors
2003 0381
The NFAT family
renal atrophy and lack of tonicity-responsive gene expression
modified from Macián et al. (2001) Oncogene 20:2476.
2004 0472
Signal transduction by
Ca2+, calcineurin and NF-AT
Crabtree (1999) Cell 96:611.
2004 0473
Signal transduction by
Ca2+, calcineurin and NF-AT
Macian (2005) Nature Reviews Immunology 5, 472-84.
2004 0473
Macián et al. (2001) Oncogene 20:2476.
ST1
ST5
ST8
Analysis of NFAT1 Phosphorylation.
Okamura et al. (2000) Mol. Cell 6:539.
ST4
ST2
The SRR-1 Region Regulates the Active Conformation of NFAT1.
Okamura et al. (2000) Mol. Cell 6:539.
Macián et al. (2001) Oncogene 20:2476.
Janus kinases
o Jak1
o Jak2
o Jak3
o Tyk2
O’Shea et al. (2004), Nature Rev. Drug Disc. 3:555-64
Signal transducer and
activator of transcription
o Stat1
o Stat2
o Stat3
o Stat4
o Stat5a
o Stat5b
o Stat6
O’Shea et al. (2004), Nature Rev. Drug Disc. 3:555-64
Benekli et al. (2003), Blood 101:2940-54
JAK/STAT signal transduction
2003 0366
STAT1 is activated by IFNg
McBride et al. (2000), EMBO J. 19:6196-206
2003 0376
STAT domain structure
and protein binding sites
Levy and Darnell. (2003),
Nature Rev. Mol. Cell Biol. 3:651-62
2003 0368
Leptomycin B inhibits nuclear export
of STAT1
McBride et al. (2000), EMBO J. 19:6196-206
2003 0372
Intracellular localization of
STAT1 DNA binding mutant
McBride et al. (2000), EMBO J. 19:6196-206
2003 0373
Identification of
STAT1 nuclear export signal
McBride et al. (2000), EMBO J. 19:6196-206
2003 0373
McBride et al. (2000), EMBO J. 19:6196-206
Effect of NES placement outside of
the STAT1 DNA biding domain
2003 0374
Grogan and Locksley (2002), Curr. Opin. Immunol. 14:366
Transcription factors in the helper
T cell differentiation
Serfling et al. (2000) Biochim. Biophys. Acta. 1498:1.
2004 0476