Background
on apoptotic cell clearance:
· Everyday, we turnover 100-200 billion cells in the
body. Generation of apoptotic cells and their turnover are part
of a normal homeostasis in the bone marrow, thymus, eye, gut etc. More
recently, several disease states such as autoimmunity (best example
being Lupus), atherosclerosis, chronic inflammation and cancer have now
been linked to failed or inadequate corpse clearance. The
apoptotic cell clearance mechanism has also been linked to axonal
pruning and part of the response to neuronal injury.
· While the process of apoptosis has been widely
studied for the past 20 years, how you ‘get rid of these bodies’ has
lagged behind. This is largely because we did not initially appreciate
that cell death in a test tube could be different from cell death
in vivo, i.e. cell death is closely coupled to rapid and
efficient, and ‘immunologically quiet’ clearance of these
corpses. To put it another way, the field of apoptosis did not
recognize the biological significance of this problem until the
‘garbage collection’ was interrupted (e.g. knockout mice with
disruption of engulfment genes or human disease states).
· Recently, the molecules and mechanisms involved in
engulfment are beginning to be defined through a combination of
genetics in C. elegans and
Drosophila, mammalian cell
line studies and mouse knockouts. This has provided a great
opportunity to begin to pick apart this problem both at the molecular
level and whole organism level and in the context of human
disease.
· In the past two years ~15 papers have been
published on this topic, just in Nature, Cell, Science, Nature Cell
Biology and Immunity.
Thus, the apoptotic cell engulfment field is quite hot and perceived by
the scientific community as having a large overall impact to many
different areas.
Why have
this Center for Cell Clearance?
· Initially, work from the Ravichandran
laboratory at the University of Virginia identified some of the
key signaling molecules involved in apoptotic cell clearance and
revealed their relevance in the context of mammals and C.
elegans. Since then, several
investigators at University of Virginia have also become
interested in the problem of apoptotic cell clearance from different
angles: such as cell clearance in the nervous system (Jim
Mandell), apoptosis and its relevance to atherosclerosis (Leitinger
and Ravichandran), turnover of cells in the gut and its relevance to
inflammatory bowel disease (Peter Ernst and Ravichandran), insights on
how amoeba can cause apoptosis and subsequently ingest these dying
lymphocytes (Petri),
clearance of apoptotic germ cells by Sertoli cells of the testes (Jeffrey
Lyisak and Ravichandran), and addressing the importance of
apoptotic cell clearance in autoimmunity (Ken
Tung). Thus, there is now a critical mass of
investigators at the University of Virginia who would be benefited from
a focused and more integrated research effort on the topic of apoptotic
cell clearance. Hence, the birth of this Center for Cell
Clearance!
· Besides those at UVA, investigators from other
institutions in the field of apoptotic cell clearance have often
expressed the view that there is a critical need to bring all of the
investigators together. While this is achieved every two years at
a Gordon Conference dedicated to apoptotic cell clearance, the field is
moving too fast and there needs to be a forum for communication between
investigators. Dr. Kodi Ravichandran, who was a Vice Chair of the
Gordon Research Conference in 2005 and Chair of the GRC meeting in 2007
has taken the lead to initiate this effort to help bring investigators
from within and outside UVA through this Center for Cell
Clearance.
Mission
for the Center for Cell Clearance:
The mission of the
Center is two fold.
First, to unite the
research efforts within University of Virginia on the topic of
apoptotic cell clearance through effective communication of ongoing
research and better sharing of ideas and reagents such that the
collective efforts make better advances than the isolated efforts of
individual investigators.
Second, the Center
for Cell Clearance aims to link investigators from around the world
through a common website run through this Center, and thereby foster
better intellectual exchange and overall progress in the field of
apoptotic cell clearance.
Goals:
Short Term
(0-3 years)
· Facilitate better coordination of the ongoing
efforts within University of Virginia and initiate new collaborative
avenues of investigation
· Hiring new faculty and fully establishing the
Center for Cell Clearance
· Creation of the CCC website useful for all
investigators (inside and outside UVA) to allow the exchange of ideas,
reagents and advice within the engulfment community
· Generation of new mouse lines useful for studies
of engulfment
· Provide a better intellectual exchange between
students, post-docs and faculty working on apoptotic cell
clearance
· Applying for collaborative grant
funding
Long Term
(0-5 years)
· Provide a mouse repository resource for knockout
and transgenic mice for the various engulfment genes that can be
acquired by all investigators in the field of apoptotic cell
clearance
· Using input from the various investigators within
and outside UVA, continually improve the mechanism(s) of intellectual
and reagent exchange between investigators in the field of apoptotic
cell clearance
· Expand the usefulness, visibility and resources of
the CCC through acquisition of additional collaborative grant funding
and Center grants