International Congress of Immunology 2016
T-bet/Blimp1 double-deficiency resulted in the derepression of
several molecules usually associated with IL-17 producing CD8
T (Tc17) cells and severe immune pathology. Overall, our data
reveal two major pathways of effector differentiation governed
by the availability of Blimp-1 and T-bet and suggest a model
for cytokine-induced transcriptional changes that combine
quantitatively and qualitatively to promote robust effector CD8
The role of SATB1 in virus-specific CD8
T cell mediated
Nuessing, S., Russ, B.E., Grant, E.J., Kedzierska, K., Turner, S.J.
University of Melbourne, Peter Doherty Institute for Infection and
Immunity, Microbiology and Immunology, Melbourne, Australia
T cells are a critical component of the immune response
to viral infection such as the influenza virus. Upon virus
T cells undergo a program
of proliferation and functional differentiation resulting in a large
cells secreting cytotoxic molecules and pro-
inflammatory cytokines required for viral clearance. Importantly,
a long-lived pool of virus-specific
T cells survives after
resolution of the infection and responds more readily following
re-infection, allowing faster viral clearance and providing the
basis of protective T cell-mediated immunity.
Changes to the structure of DNA-protein complexes, within
respondingT cells underpin the differences in gene transcription
that confer the functional and phenotypic differences between
naïve, effector, and memory T cells. SATB1 is a master regulator
of chromatin structure, and as such, a key regulator of
transcription. We have shown that
is expressed in naïve
T cells, down-regulated as naïve cells differentiate to effector
and then memory, in both mice and human. Additionally,
characterization of mice baring a dysfunctional
revealed a depletion of T cells baring the CD44
a gene up-regulated after T cell activation. On this basis, we
hypothesize that SATB1 regulates CD8
T cell differentiation. To
address this hypothesis, we use next generation sequencing
methods to characterize the genome-wide distribution of
SATB1 binding at each stage of T cell differentiation. Combining
these data with transcriptomic analyses of the wild-type and
mutant mice will provide insights into the role of SATB1 in
mediating virus-specific CD8
T cell differentiation.
Transcriptional networks that establish B cell identity
, Miyai, T.
, Kawamoto, H.
RIKENCenter for IntegrativeMedical Sciences, Yokohama, Japan,
KyotoUniversity, Institute for Frontier Medical Sciences, Kyoto, Japan
B lymphocytes are generated from hematopoietic stem
cells (HSCs) through a successive series of lineage restriction
processes. Although many transcription factors (TFs) and
epigenetic regulators have been implicated in controlling the B
cell fate specification, exact mechanisms remain elusive.
We have recently established a culture system that can
examine gene regulatory networks of HSCs differentiating
into B cell lineage (Ikawa et al. 2015). We overexpressed Id3
protein fused with ERT2 (Estrogen receptor) protein whose
nuclear translocation is induced by 4-hydroxytamoxifen (4-
OHT) in hematopoietic progenitors and cultured them in B cell
differentiation condition. B cell development of Id3-transduced
cells was blocked at an early developmental stage and the
cells grew enormously with maintaining multipotency in the
presence of 4-OHT. Virtually all cells became CD19+ B cells by
simply withdrawing 4-OHT within 7 days. We then performed
RNA-Seq analysis at multiple time points in this system.
The expressions of “master” TFs such as Ebf1 and Pax5 were
dramatically upregulated after 48hrs of induction. Notably,
the sequential upregulation of TFs before the onset of the key
TF program was found. The earliest responding TFs such as
Egr1 and Klf4 had a peak at 0.5-2hrs followed by a continuous
stream of TFs within 24hrs. Knockdown of these genes led to
the defected B cell generation both in vivo and in vitro. Taken
together, our findings identified a genome-wide view of the
dynamic transcriptional waves in B cell fate determination.
Hierarchical regulation of enhancer establishment and gene
expression by transcription factors during mononuclear
, Nakabayashi, J.
, Nishiyama, A.
, Sasaki, H.
, Ozato, K.
, Suzuki, Y.
, Tamura, T.
Yokohama City University Graduate School of Medicine,
Department of Immunology, Yokohama, Japan,
University, Advanced Medical Research Center, Yokohama, Japan,
NICHD, NIH, Bethesda, United States,
Graduate School of Frontier
Sciences, University of Tokyo, Department of Computational
Biology, Chiba, Japan
Monocytes and dendritic cells (DCs) are mononuclear
phagocytes essential for innate and adaptive immunity.
These phagocytes develop from hematopoietic stem cells
via intermediate progenitors, such as granulocyte-monocyte
progenitors (GMPs), monocyte-DC progenitors (MDPs), and
common monocyte progenitors (cMoPs) or common DC
progenitors (CDPs). However, the molecular mechanism
underlying their differentiation potential remains incompletely
understood. Recent studies suggest that promoter-distal
enhancers are key for cell fate decision. In this study, we
(ChIP-seq) analysis of enhancer-related histone modifications
(H3K4me1 and H3K27ac) in GMPs, MDPs, cMoPs, CDPs,
monocytes, DCs, and neutrophils. We found that monocyte- and
DC-specific enhancers were gradually established at progenitor
stages prior to gene expression. DNA motif analysis implicated
that these enhancers were regulated by combinations of
lineage-determining transcription factors such as PU.1, RUNX,
C/EBP, and IRF. Interestingly, the motifs specifically enriched
in the mononuclear phagocyte lineage were the IRF binding
motifs. Among IRFs, IRF8 is known to be highly expressed
from the MDP stage and necessary for MDP-to-CDP and
cMoP-to-monocyte transitions. Somewhat unexpectedly,
however, global gene expression patterns were comparable