Kwun Wah Wen | University of Pennsylvania (original) (raw)
Papers by Kwun Wah Wen
PLoS pathogens, 2012
Heat-shock protein 90 (Hsp90) inhibitors exhibit activity against human cancers. We evaluated a s... more Heat-shock protein 90 (Hsp90) inhibitors exhibit activity against human cancers. We evaluated a series of new, oral bioavailable, chemically diverse Hsp90 inhibitors (PU-H71, AUY922, BIIB021, NVP-BEP800) against Kaposi sarcoma (KS). All Hsp90 inhibitors exhibited nanomolar EC(50) in culture and AUY922 reduced tumor burden in a xenograft model of KS. KS is associated with KS-associated herpesvirus (KSHV). We identified the viral latency associated nuclear antigen (LANA) as a novel client protein of Hsp90 and demonstrate that the Hsp90 inhibitors diminish the level of LANA through proteasomal degradation. These Hsp90 inhibitors also downregulated EphA2 and ephrin-B2 protein levels. LANA is essential for viral maintenance and EphA2 has recently been shown to facilitate KSHV infection; which in turn feeds latent persistence. Further, both molecules are required for KS tumor formation and both were downregulated in response to Hsp90 inhibitors. This provides a rationale for clinical test...
Immunity, 2012
The mitochondrial protein MAVS (also known as IPS-1, VISA, and CARDIF) interacts with RIG-I-like ... more The mitochondrial protein MAVS (also known as IPS-1, VISA, and CARDIF) interacts with RIG-I-like receptors (RLRs) to induce type I interferon (IFN-I). NLRX1 is a mitochondrial nucleotide-binding, leucine-rich repeats (NLR)-containing protein that attenuates MAVS-RLR signaling. Using Nlrx1 À/À cells, we confirmed that NLRX1 attenuated IFN-I production, but additionally promoted autophagy during viral infection. This dual function of NLRX1 paralleled the previously described functions of the autophagy-related proteins Atg5-Atg12, but NLRX1 did not associate with Atg5-Atg12. High-throughput quantitative mass spectrometry and endogenous protein-protein interaction revealed an NLRX1interacting partner, mitochondrial Tu translation elongation factor (TUFM). TUFM interacted with Atg5-Atg12 and Atg16L1 and has similar functions as NLRX1 by inhibiting RLR-induced IFN-I but promoting autophagy. In the absence of NLRX1, increased IFN-I and decreased autophagy provide an advantage for host defense against vesicular stomatitis virus. This study establishes a link between an NLR protein and the viral-induced autophagic machinery via an intermediary partner, TUFM.
Oncogene, 2010
Kaposi sarcoma-associated herpesvirus (KSHV) is a member of the gammaherpesvirus family. It is th... more Kaposi sarcoma-associated herpesvirus (KSHV) is a member of the gammaherpesvirus family. It is the etiological agent of three different human cancers, Kaposi sarcoma (KS), primary effusion lymphoma (PEL) and multicentric Castleman disease. The far left end of the KSHV genome encodes a unique transmembrane glycoprotein called K1. K1 possesses the ability to transform rodent fibroblasts and block apoptosis. K1 has also been shown to activate the PI3K/Akt/mTOR pathway in different cells. Using tandem affinity purification, we identified heat shock protein 90b (Hsp90b) and endoplasmic reticulum-associated Hsp40 (Erdj3/DnaJB11), as cellular binding partners of K1. Interactions of K1 with Hsp90b and Hsp40 were confirmed by co-immunoprecipitation in both directions. Furthermore, K1 also interacted with the Hsp90a isoform. We report that smallinterfering RNAs directed against Hsp90 and Hsp40/ Erdj3, as well as pharmacological inhibitors of Hsp90, dramatically reduced K1 expression, suggesting that K1 is a client protein of these chaperones. In addition, both Hsp90 and Hsp40/Erdj3 were essential for K1's antiapoptotic function. Finally, we report that the Hsp90 inhibitors, 17-AAG and 17-DMAG, can suppress the proliferation of KSHV-positive PEL cell lines and exhibited IC 50 values of 50 nM and below.
The propensity of naive CD4 T cells to become T helper (Th) type 2 cells correlates with suscepti... more The propensity of naive CD4 T cells to become T helper (Th) type 2 cells correlates with susceptibility to infection by the protozoal parasite Leishmania major . Using genetic linkage analysis, we earlier identified Dice1 as a Th2 cell bias-controlling quantitative trait locus on chromosome 16. Using interval-specific congenic mapping, we now resolve Dice1 into two independent genetic loci, Dice1.1 and Dice1.2 , which control Il4 expression from naive Th cells and thereby indirectly control Th2 cell bias. Interestingly, only one of the two congenic intervals containing Dice1.1 and Dice1.2 , respectively, also contained an L. major response locus, indicating that L. major responsiveness can be insensitive to determinants that influence Th2 cell bias by controlling naive T cell Il4 expression. These results lay the groundwork for identifying the Dice1.1 and Dice1.2 genes controlling naive T cell Il4 expression and L. major responses, and for testing whether these control other Th2 cell-dependent processes such as worm expulsion, allergic asthma, and dermatitis.
Journal of Virology, 2009
RRV is the closest relative to KSHV that has a fully sequenced genome and serves as an in vitro a... more RRV is the closest relative to KSHV that has a fully sequenced genome and serves as an in vitro and an in vivo model system for KSHV. The latency-associated nuclear antigen (LANA) protein of both KSHV and RRV plays key roles in the establishment and maintenance of these herpesviruses. We have constructed a RRV recombinant virus (RRV⌬LANA/GFP) in which the RRV LANA open reading frame has been disrupted with a green fluorescent protein (GFP) expression cassette generated by homologous recombination. The integrity of the recombinant virus was confirmed by diagnostic PCR, restriction digestion, Southern blot analysis, and whole-genome sequencing. We compared the single-step and multistep replication kinetics of RRV⌬LANA/GFP, RRV-GFP, wild-type (WT) RRV H26-95, and a revertant virus using traditional plaque assays, as well as real-time quantitative PCR-based genome quantification assays. The RRV⌬LANA/GFP recombinant virus exhibited significantly higher lytic replicative properties compared to RRV-GFP, WT RRV, or the revertant virus. This was observed upon de novo infection and in the absence of chemical inducers such as phorbol esters. In addition, by using a quantitative real-time PCR-based viral array, we are the first to report differences in global viral gene expression between WT and recombinant viruses. The RRV⌬LANA/GFP virus displayed increased lytic gene transcription at all time points postinfection compared to RRV-GFP. Moreover, we also examined several cellular genes that are known to be repressed by KSHV LANA and report that these genes are derepressed during de novo lytic infection with the RRV⌬LANA/GFP virus compared to RRV-GFP. Finally, we also demonstrate that the RRV⌬LANA/GFP virus fails to establish latency in B cells, as measured by the loss of GFP-positive cells and intracellular viral genomes.
Cancer Letters, 2010
Kaposi sarcoma-associated herpesvirus (KSHV) is a double-stranded DNA herpesvirus belonging to th... more Kaposi sarcoma-associated herpesvirus (KSHV) is a double-stranded DNA herpesvirus belonging to the c-herpesvirinae subfamily. KSHV has been associated with the development of three neoplastic diseases: Kaposi sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman disease (MCD). In this review, we discuss the three KSHV-associated malignancies, KSHV genome, latent and lytic aspects of the viral lifecycle, putative viral oncogenes, as well as therapeutic regimens used for the treatment of KS, PEL, and MCD.
Kaposi sarcoma-associated herpesvirus (KSHV) is a double-stranded DNA herpesvirus belonging to th... more Kaposi sarcoma-associated herpesvirus (KSHV) is a double-stranded DNA herpesvirus belonging to the c-herpesvirinae subfamily. KSHV has been associated with the development of three neoplastic diseases: Kaposi sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman disease (MCD). In this review, we discuss the three KSHV-associated malignancies, KSHV genome, latent and lytic aspects of the viral lifecycle, putative viral oncogenes, as well as therapeutic regimens used for the treatment of KS, PEL, and MCD.
PLoS pathogens, 2012
Heat-shock protein 90 (Hsp90) inhibitors exhibit activity against human cancers. We evaluated a s... more Heat-shock protein 90 (Hsp90) inhibitors exhibit activity against human cancers. We evaluated a series of new, oral bioavailable, chemically diverse Hsp90 inhibitors (PU-H71, AUY922, BIIB021, NVP-BEP800) against Kaposi sarcoma (KS). All Hsp90 inhibitors exhibited nanomolar EC(50) in culture and AUY922 reduced tumor burden in a xenograft model of KS. KS is associated with KS-associated herpesvirus (KSHV). We identified the viral latency associated nuclear antigen (LANA) as a novel client protein of Hsp90 and demonstrate that the Hsp90 inhibitors diminish the level of LANA through proteasomal degradation. These Hsp90 inhibitors also downregulated EphA2 and ephrin-B2 protein levels. LANA is essential for viral maintenance and EphA2 has recently been shown to facilitate KSHV infection; which in turn feeds latent persistence. Further, both molecules are required for KS tumor formation and both were downregulated in response to Hsp90 inhibitors. This provides a rationale for clinical test...
Immunity, 2012
The mitochondrial protein MAVS (also known as IPS-1, VISA, and CARDIF) interacts with RIG-I-like ... more The mitochondrial protein MAVS (also known as IPS-1, VISA, and CARDIF) interacts with RIG-I-like receptors (RLRs) to induce type I interferon (IFN-I). NLRX1 is a mitochondrial nucleotide-binding, leucine-rich repeats (NLR)-containing protein that attenuates MAVS-RLR signaling. Using Nlrx1 À/À cells, we confirmed that NLRX1 attenuated IFN-I production, but additionally promoted autophagy during viral infection. This dual function of NLRX1 paralleled the previously described functions of the autophagy-related proteins Atg5-Atg12, but NLRX1 did not associate with Atg5-Atg12. High-throughput quantitative mass spectrometry and endogenous protein-protein interaction revealed an NLRX1interacting partner, mitochondrial Tu translation elongation factor (TUFM). TUFM interacted with Atg5-Atg12 and Atg16L1 and has similar functions as NLRX1 by inhibiting RLR-induced IFN-I but promoting autophagy. In the absence of NLRX1, increased IFN-I and decreased autophagy provide an advantage for host defense against vesicular stomatitis virus. This study establishes a link between an NLR protein and the viral-induced autophagic machinery via an intermediary partner, TUFM.
Oncogene, 2010
Kaposi sarcoma-associated herpesvirus (KSHV) is a member of the gammaherpesvirus family. It is th... more Kaposi sarcoma-associated herpesvirus (KSHV) is a member of the gammaherpesvirus family. It is the etiological agent of three different human cancers, Kaposi sarcoma (KS), primary effusion lymphoma (PEL) and multicentric Castleman disease. The far left end of the KSHV genome encodes a unique transmembrane glycoprotein called K1. K1 possesses the ability to transform rodent fibroblasts and block apoptosis. K1 has also been shown to activate the PI3K/Akt/mTOR pathway in different cells. Using tandem affinity purification, we identified heat shock protein 90b (Hsp90b) and endoplasmic reticulum-associated Hsp40 (Erdj3/DnaJB11), as cellular binding partners of K1. Interactions of K1 with Hsp90b and Hsp40 were confirmed by co-immunoprecipitation in both directions. Furthermore, K1 also interacted with the Hsp90a isoform. We report that smallinterfering RNAs directed against Hsp90 and Hsp40/ Erdj3, as well as pharmacological inhibitors of Hsp90, dramatically reduced K1 expression, suggesting that K1 is a client protein of these chaperones. In addition, both Hsp90 and Hsp40/Erdj3 were essential for K1's antiapoptotic function. Finally, we report that the Hsp90 inhibitors, 17-AAG and 17-DMAG, can suppress the proliferation of KSHV-positive PEL cell lines and exhibited IC 50 values of 50 nM and below.
The propensity of naive CD4 T cells to become T helper (Th) type 2 cells correlates with suscepti... more The propensity of naive CD4 T cells to become T helper (Th) type 2 cells correlates with susceptibility to infection by the protozoal parasite Leishmania major . Using genetic linkage analysis, we earlier identified Dice1 as a Th2 cell bias-controlling quantitative trait locus on chromosome 16. Using interval-specific congenic mapping, we now resolve Dice1 into two independent genetic loci, Dice1.1 and Dice1.2 , which control Il4 expression from naive Th cells and thereby indirectly control Th2 cell bias. Interestingly, only one of the two congenic intervals containing Dice1.1 and Dice1.2 , respectively, also contained an L. major response locus, indicating that L. major responsiveness can be insensitive to determinants that influence Th2 cell bias by controlling naive T cell Il4 expression. These results lay the groundwork for identifying the Dice1.1 and Dice1.2 genes controlling naive T cell Il4 expression and L. major responses, and for testing whether these control other Th2 cell-dependent processes such as worm expulsion, allergic asthma, and dermatitis.
Journal of Virology, 2009
RRV is the closest relative to KSHV that has a fully sequenced genome and serves as an in vitro a... more RRV is the closest relative to KSHV that has a fully sequenced genome and serves as an in vitro and an in vivo model system for KSHV. The latency-associated nuclear antigen (LANA) protein of both KSHV and RRV plays key roles in the establishment and maintenance of these herpesviruses. We have constructed a RRV recombinant virus (RRV⌬LANA/GFP) in which the RRV LANA open reading frame has been disrupted with a green fluorescent protein (GFP) expression cassette generated by homologous recombination. The integrity of the recombinant virus was confirmed by diagnostic PCR, restriction digestion, Southern blot analysis, and whole-genome sequencing. We compared the single-step and multistep replication kinetics of RRV⌬LANA/GFP, RRV-GFP, wild-type (WT) RRV H26-95, and a revertant virus using traditional plaque assays, as well as real-time quantitative PCR-based genome quantification assays. The RRV⌬LANA/GFP recombinant virus exhibited significantly higher lytic replicative properties compared to RRV-GFP, WT RRV, or the revertant virus. This was observed upon de novo infection and in the absence of chemical inducers such as phorbol esters. In addition, by using a quantitative real-time PCR-based viral array, we are the first to report differences in global viral gene expression between WT and recombinant viruses. The RRV⌬LANA/GFP virus displayed increased lytic gene transcription at all time points postinfection compared to RRV-GFP. Moreover, we also examined several cellular genes that are known to be repressed by KSHV LANA and report that these genes are derepressed during de novo lytic infection with the RRV⌬LANA/GFP virus compared to RRV-GFP. Finally, we also demonstrate that the RRV⌬LANA/GFP virus fails to establish latency in B cells, as measured by the loss of GFP-positive cells and intracellular viral genomes.
Cancer Letters, 2010
Kaposi sarcoma-associated herpesvirus (KSHV) is a double-stranded DNA herpesvirus belonging to th... more Kaposi sarcoma-associated herpesvirus (KSHV) is a double-stranded DNA herpesvirus belonging to the c-herpesvirinae subfamily. KSHV has been associated with the development of three neoplastic diseases: Kaposi sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman disease (MCD). In this review, we discuss the three KSHV-associated malignancies, KSHV genome, latent and lytic aspects of the viral lifecycle, putative viral oncogenes, as well as therapeutic regimens used for the treatment of KS, PEL, and MCD.
Kaposi sarcoma-associated herpesvirus (KSHV) is a double-stranded DNA herpesvirus belonging to th... more Kaposi sarcoma-associated herpesvirus (KSHV) is a double-stranded DNA herpesvirus belonging to the c-herpesvirinae subfamily. KSHV has been associated with the development of three neoplastic diseases: Kaposi sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman disease (MCD). In this review, we discuss the three KSHV-associated malignancies, KSHV genome, latent and lytic aspects of the viral lifecycle, putative viral oncogenes, as well as therapeutic regimens used for the treatment of KS, PEL, and MCD.