Francis Ka-Ming Chan

Overview:

Our lab is interested in how cell death impacts innate inflammation and immune responses.  We have a long-standing interest in the biology and signaling mechanism of tumor necrosis factor (TNF), a key cytokine that regulates many inflammatory diseases (e.g. rheumatoid arthritis, inflammatory bowel diseases etc), pathogen infections, and cancer.  Several key discoveries made by the PI during his graduate school and postdoctoral training include identification of one of the first cell cycle inhibitors, INK4d-p19 (Mol Cell Biol. 1995, cited over 300 times), and the discovery of the "pre-ligand assembly domain (PLAD)" that mediates TNF receptors signal transduction (Science 2000, cited over 800 times).

In recent years, we have focused our effort on elucidating the signaling mechanism of a novel form of inflammatory cell death termed necroptosis.  In 2009, our group identified Receptor Interacting Protein kinase 3 (RIPK3) as a central mediator of necroptosis (Cell, 2009, cited over 1000 times).  Current projects include (1) deciphering the signaling mechanisms of necroptosis, (2) interrogation of the biology of RIPK3 and related necroptosis signaling molecules in intestinal wound healing and inflammation, (3) elucidation of the role of necroptosis in pathogen infections, and many others. 

We aim to take the knowledge we gain from basic pathway discovery to better understand the principles of immune regulation.  We believe our endeavor will pave the way for more efficacious therapeutic intervention in auto-inflammatory diseases, cancers and pathogen infections.

Current research projects in the lab include the following broad areas.  Interested students and postdoctoral candidates are encouraged to contact Dr. Chan for more information on rotation projects and research opportunities.

1. The role of necroptosis signal adaptors in inflammatory diseases
We are interested in how the kinases RIPK1 and RIPK3, both of which have critical functions in cell death, contribute to injury-induced inflammation and tissue repair.  Currently, we are using mouse models of intestinal injury and inflammation to study the function of these signal adaptors in intestinal homeostasis.

2. The role of cell death in anti-viral immune responses
We have discovered that necroptosis is an important innate immune defense mechanism against certain viruses.  We are interested in how host cell death during pathogen infections can alter the course of the host immune response.  On the other hand, we are also interested in exploring the mechanisms employed by different viral pathogens in combating the host cell death machinery.

3. Signaling mechanism of RIP kinases in cell death and inflammation
We found that the RIP kinases can promote inflammation through cell death-dependent and independent mechanisms.  What are the molecular events that regulate the diverse functions of the RIP kinases?  We are using biochemical, cell biological, and genetic tools to dissect the molecular regulation of these important immune signaling molecules.

Positions:

Adjunct Professor in the Department of Immunology

Immunology
School of Medicine

Member of the Duke Cancer Institute

Duke Cancer Institute
School of Medicine

Education:

Ph.D. 1996

University of California - Berkeley

Grants:

Necroptosis signaling adaptors in inflammatory diseases

Administered By
Immunology
Awarded By
National Institutes of Health
Role
Principal Investigator
Start Date
End Date

Viral mechanisms of necroptosis evasion

Administered By
Immunology
Awarded By
National Institutes of Health
Role
Principal Investigator
Start Date
End Date

Viral inhibition of cell death in host immune responses

Administered By
Immunology
Awarded By
National Institutes of Health
Role
Principal Investigator
Start Date
End Date

Viral inhibition of cell death in host immune responses

Administered By
Immunology
Awarded By
National Institutes of Health
Role
Principal Investigator
Start Date
End Date

Viral inhibition of cell death in host immune responses

Administered By
Immunology
Awarded By
National Institutes of Health
Role
Principal Investigator
Start Date
End Date

Publications:

Generation of recombinant vaccinia virus and analysis of virus-induced cell death.

Vaccinia virus is a large double-stranded DNA virus that is widely used to express foreign genes from different origins. We generated recombinant vaccinia virus that expresses a viral inhibitor to examine its effect on virus-induced necroptosis. We provide a detailed protocol to describe the generation of recombinant vaccinia virus, validation of protein expression, and determination of necroptosis using live cell imaging. This approach can be adapted to examine the effect of other cell death regulators on virus-induced cell death. For complete details on the use and execution of this protocol, please refer to Liu et al. (2021).
Authors
Liu, Z; Kang, K; Ka-Ming Chan, F
MLA Citation
Liu, Zhijun, et al. “Generation of recombinant vaccinia virus and analysis of virus-induced cell death.” Star Protoc, vol. 2, no. 4, Dec. 2021, p. 100871. Pubmed, doi:10.1016/j.xpro.2021.100871.
URI
https://scholars.duke.edu/individual/pub1499241
PMID
34661172
Source
pubmed
Published In
Star Protocols
Volume
2
Published Date
Start Page
100871
DOI
10.1016/j.xpro.2021.100871

Necroptosis at a glance.

Necroptosis, or programmed necrosis, is an inflammatory form of cell death with important functions in host defense against pathogens and tissue homeostasis. The four cytosolic receptor-interacting protein kinase homotypic interaction motif (RHIM)-containing adaptor proteins RIPK1, RIPK3, TRIF (also known as TICAM1) and ZBP1 mediate necroptosis induction in response to infection and cytokine or innate immune receptor activation. Activation of the RHIM adaptors leads to phosphorylation, oligomerization and membrane targeting of the necroptosis effector protein mixed lineage kinase domain-like (MLKL). Active MLKL induces lesions on the plasma membrane, leading to the release of pro-inflammatory damage-associated molecular patterns (DAMPs). Thus, activities of the RHIM adaptors and MLKL are tightly regulated by posttranslational modifications to prevent inadvertent release of immunogenic contents. In this Cell Science at a Glance article and the accompanying poster, we provide an overview of the regulatory mechanisms of necroptosis and its biological functions in tissue homeostasis, pathogen infection and other inflammatory diseases.
Authors
MLA Citation
Kang, Kidong, et al. “Necroptosis at a glance.” J Cell Sci, vol. 135, no. 17, Sept. 2022. Pubmed, doi:10.1242/jcs.260091.
URI
https://scholars.duke.edu/individual/pub1550019
PMID
36098620
Source
pubmed
Published In
J Cell Sci
Volume
135
Published Date
DOI
10.1242/jcs.260091

Tumor-intrinsic and immune modulatory roles of receptor-interacting protein kinases.

Receptor-interacting protein kinase 1 (RIPK1) and RIPK3 are signaling adaptors that critically regulate cell death and inflammation. Tumors have adapted to subvert RIPK-dependent cell death, suggesting that these processes have key roles in tumor regulation. Moreover, RIPK-driven cancer cell death might bolster durable antitumor immunity. By contrast, there are examples in which RIPKs induce inflammation and aid tumor progression. Furthermore, the RIPKs can exert their effects on tumor growth through regulating the activity of immune effectors in the tumor microenvironment, thus highlighting the context-dependent roles of RIPKs. Here, we review recent advances in the regulation of RIPK activity in tumors and immune cells and how these processes coordinate with each other to control tumorigenesis.
Authors
Rucker, AJ; Chan, FK-M
MLA Citation
Rucker, A. Justin, and Francis Ka-Ming Chan. “Tumor-intrinsic and immune modulatory roles of receptor-interacting protein kinases.” Trends Biochem Sci, vol. 47, no. 4, Apr. 2022, pp. 342–51. Pubmed, doi:10.1016/j.tibs.2021.12.004.
URI
https://scholars.duke.edu/individual/pub1506125
PMID
34998669
Source
pubmed
Published In
Trends in Biochemical Sciences
Volume
47
Published Date
Start Page
342
End Page
351
DOI
10.1016/j.tibs.2021.12.004

RIPK1-RIPK3-MLKL-Associated Necroptosis Drives Leishmania infantum Killing in Neutrophils.

Necroptosis is a pro-inflammatory cell death, which happens in the context of caspase-8 inhibition, allowing activation of the receptor interacting protein kinase 1-receptor interacting protein kinase 3-mixed lineage kinase domain-like (RIPK1-RIPK3-MLKL) axis. Recently, necroptosis has emerged as a key component of resistance against pathogens including infected macrophage by Leishmania infantum, the ethiologic agent of Visceral leishmaniasis (VL). VL is the most severe form of Leishmaniasis, characterized by systemic inflammation and neutropenia. However, the role of neutrophil cell death in VL has not been characterized. Here, we showed that VL patients exhibited increased lactate dehydrogenase levels in the serum, a hallmark of cell death and tissue damage. We investigated the effect of necroptosis in neutrophil infection in vitro. Human neutrophils pretreated with zVAD-fmk (pan-caspase inhibitor) and zIETD-fmk (caspase-8 inhibitor) increased reactive oxygen species (ROS) level in response to Leishmania infection, which is associated with necroptotic cell death. MLKL, an important effector molecule downstream of necroptosis pathway, was also required for Leishmania killing. Moreover, in absence of caspases-8, murine neutrophils displayed loss of membrane integrity, higher levels of ROS, and decreased L. infantum viability. Pharmacological inhibition of RIPK1 or RIPK3 increased parasite survival when caspase-8 was blocked. Electron microscopy assays revealed morphological features associated with necroptotic death in L. infantum infected-neutrophils pretreated with caspase inhibitor, whereas infected cells pretreated with RIPK1 and RIPK3 inhibitors did not show ultra-structural alterations in membrane integrity and presented viable Leishmania within parasitophorous vacuoles. Taken together, these findings suggest that inhibition of caspase-8 contributes to elimination of L. infantum in neutrophils by triggering necroptosis. Thus, targeting necroptosis may represent a new strategy to control Leishmania replication.
Authors
Barbosa, LA; Fiuza, PP; Borges, LJ; Rolim, FA; Andrade, MB; Luz, NF; Quintela-Carvalho, G; Lima, JB; Almeida, RP; Chan, FK; Bozza, MT; Borges, VM; Prates, DB
MLA Citation
Barbosa, Laiana A., et al. “RIPK1-RIPK3-MLKL-Associated Necroptosis Drives Leishmania infantum Killing in Neutrophils.” Front Immunol, vol. 9, 2018, p. 1818. Pubmed, doi:10.3389/fimmu.2018.01818.
URI
https://scholars.duke.edu/individual/pub1489400
PMID
30154785
Source
pubmed
Published In
Frontiers in Immunology
Volume
9
Published Date
Start Page
1818
DOI
10.3389/fimmu.2018.01818

Detection of necrosis by release of lactate dehydrogenase activity.

Apoptosis and necrosis are two major forms of cell death observed in normal and disease pathologies. Although there are many assays for detection of apoptosis, relatively few assays are available for measuring necrosis. A key signature for necrotic cells is the permeabilization of the plasma membrane. This event can be quantified in tissue culture settings by measuring the release of the intracellular enzyme lactate dehydrogenase (LDH). When combined with other methods, measuring LDH release is a useful method for the detection of necrosis. In this chapter, we describe the step-by-step procedure for detection of LDH release from necrotic cells using a microtiter plate-based colorimetric absorbance assay.
Authors
Chan, FK-M; Moriwaki, K; De Rosa, MJ
MLA Citation
Chan, Francis Ka-Ming, et al. “Detection of necrosis by release of lactate dehydrogenase activity.” Methods Mol Biol, vol. 979, 2013, pp. 65–70. Pubmed, doi:10.1007/978-1-62703-290-2_7.
URI
https://scholars.duke.edu/individual/pub1498613
PMID
23397389
Source
pubmed
Published In
Methods Mol Biol
Volume
979
Published Date
Start Page
65
End Page
70
DOI
10.1007/978-1-62703-290-2_7
Adjunct Professor in the Department of Immunology

Contact:

Profile

https://scholars.duke.edu/person/FrancisKaMing.Chan

Email

franciskaming.chan@duke.edu
312 Jones Building, DUMC 3010, Durham, NC 27710
Jones 312, DUMC 3010, Durham, NC 27710