Rachel Liou - Academia.edu (original) (raw)

Papers by Rachel Liou

Research paper thumbnail of Optimal surgeon-volume threshold for neck dissections in the setting of primary thyroid malignancies

Research paper thumbnail of Open Repair of a Plantar Artery Pseudoaneurysm after Morton’s Neurectomy

Journal of Vascular Surgery Cases and Innovative Techniques

Research paper thumbnail of LFA-1 and CD62L dependent transient surface CCR5 expression in naïve CD8+ T cells enhances T cell immune memory (CCR3P.214)

The Journal of Immunology, May 1, 2014

Research paper thumbnail of Transient Surface CCR5 Expression by Naive CD8+ T Cells within Inflamed Lymph Nodes Is Dependent on High Endothelial Venule Interaction and Augments Th Cell-Dependent Memory Response

Journal of immunology (Baltimore, Md. : 1950), May 18, 2016

In inflamed lymph nodes, Ag-specific CD4(+) and CD8(+) T cells encounter Ag-bearing dendritic cel... more In inflamed lymph nodes, Ag-specific CD4(+) and CD8(+) T cells encounter Ag-bearing dendritic cells and, together, this complex enhances the release of CCL3 and CCL4, which facilitate additional interaction with naive CD8(+) T cells. Although blocking CCL3 and CCL4 has no effect on primary CD8(+) T cell responses, it dramatically impairs the development of memory CD8(+) T cells upon Ag rechallenge. Despite the absence of detectable surface CCR5 expression on circulating native CD8(+) T cells, these data imply that naive CD8(+) T cells are capable of expressing surface CCR5 prior to cognate Ag-induced TCR signaling in inflamed lymph nodes; however, the molecular mechanisms have not been characterized to date. In this study, we show that CCR5, the receptor for CCL3 and CCL4, can be transiently upregulated on a subset of naive CD8(+) T cells and that this upregulation is dependent on direct contact with the high endothelial venule in inflamed lymph node. Binding of CD62L and CD11a on T...

Research paper thumbnail of Intravital Imaging of the Mouse Popliteal Lymph Node

Lymph nodes (LNs) are secondary lymphoid organs, which are strategically located throughout the b... more Lymph nodes (LNs) are secondary lymphoid organs, which are strategically located throughout the body to allow for trapping and presentation of foreign antigens from peripheral tissues to prime the adaptive immune response. Juxtaposed between innate and adaptive immune responses, the LN is an ideal site to study immune cell interactions 1,2. Lymphocytes (T cells, B cells and NK cells), dendritic cells (DCs), and macrophages comprise the bulk of bone marrow-derived cellular elements of the LN. These cells are strategically positioned in the LN to allow efficient surveillance of self antigens and potential foreign antigens 3-5. The process by which lymphocytes successfully encounter cognate antigens is a subject of intense investigation in recent years, and involves an integration of molecular contacts including antigen receptors, adhesion molecules, chemokines, and stromal structures such as the fibro-reticular network 2,6-12. Prior to the development of high-resolution real-time fluorescent in vivo imaging, investigators relied on static imaging, which only offers answers regarding morphology, position, and architecture. While these questions are fundamental in our understanding of immune cell behavior, the limitations intrinsic with this technique does not permit analysis to decipher lymphocyte trafficking and environmental clues that affect dynamic cell behavior. Recently, the development of intravital two-photon laser scanning microscopy (2P-LSM) has allowed investigators to view the dynamic movements and interactions of individual cells within live LNs in situ 12-16. In particular, we and others have applied this technique to image cellular behavior and interactions within the popliteal LN, where its compact, dense nature offers the advantage of multiplex data acquisition over a large tissue area with diverse tissue sub-structures 11,17-18. It is important to note that this technique offers added benefits over explanted tissue imaging techniques, which require disruption of blood, lymph flow, and ultimately the cellular dynamics of the system. Additionally, explanted tissues have a very limited window of time in which the tissue remains viable for imaging after explant. With proper hydration and monitoring of the animal's environmental conditions, the imaging time can be significantly extended with this intravital technique. Here, we present a detailed method of preparing mouse popliteal LN for the purpose of performing intravital imaging.

Research paper thumbnail of Quantification of lymph node transit times reveals differences in antigen surveillance strategies of naive CD4+ and CD8+ T cells

Proceedings of the National Academy of Sciences, 2012

Research paper thumbnail of Administration of Reconstituted Polyphenol Oil Bodies Efficiently Suppresses Dendritic Cell Inflammatory Pathways and Acute Intestinal Inflammation

PLoS ONE, 2014

Polyphenols are natural compounds capable of interfering with the inflammatory pathways of severa... more Polyphenols are natural compounds capable of interfering with the inflammatory pathways of several in vitro model systems. In this study, we developed a stable and effective strategy to administer polyphenols to treat in vivo models of acute intestinal inflammation. The in vitro suppressive properties of several polyphenols were first tested and compared for dendritic cells (DCs) production of inflammatory cytokines. A combination of the polyphenols, quercetin and piperine, were then encapsulated into reconstituted oil bodies (OBs) in order to increase their stability. Our results showed that administration of low dose reconstituted polyphenol OBs inhibited LPS-mediated inflammatory cytokine secretion, including IL-6, IL-23, and IL-12, while increasing IL-10 and IL-1Rα production. Mice treated with the polyphenol-containing reconstituted OBs (ROBs) were partially protected from dextran sodium sulfate (DSS)-induced colitis and associated weight loss, while mortality and inflammatory scores revealed an overall anti-inflammatory effect that was likely mediated by impaired DC immune responses. Our study indicates that the administration of reconstituted quercetin and piperine-containing OBs may represent an effective and potent anti-inflammatory strategy to treat acute intestinal inflammation.

Research paper thumbnail of Optimal surgeon-volume threshold for neck dissections in the setting of primary thyroid malignancies

Research paper thumbnail of Open Repair of a Plantar Artery Pseudoaneurysm after Morton’s Neurectomy

Journal of Vascular Surgery Cases and Innovative Techniques

Research paper thumbnail of LFA-1 and CD62L dependent transient surface CCR5 expression in naïve CD8+ T cells enhances T cell immune memory (CCR3P.214)

The Journal of Immunology, May 1, 2014

Research paper thumbnail of Transient Surface CCR5 Expression by Naive CD8+ T Cells within Inflamed Lymph Nodes Is Dependent on High Endothelial Venule Interaction and Augments Th Cell-Dependent Memory Response

Journal of immunology (Baltimore, Md. : 1950), May 18, 2016

In inflamed lymph nodes, Ag-specific CD4(+) and CD8(+) T cells encounter Ag-bearing dendritic cel... more In inflamed lymph nodes, Ag-specific CD4(+) and CD8(+) T cells encounter Ag-bearing dendritic cells and, together, this complex enhances the release of CCL3 and CCL4, which facilitate additional interaction with naive CD8(+) T cells. Although blocking CCL3 and CCL4 has no effect on primary CD8(+) T cell responses, it dramatically impairs the development of memory CD8(+) T cells upon Ag rechallenge. Despite the absence of detectable surface CCR5 expression on circulating native CD8(+) T cells, these data imply that naive CD8(+) T cells are capable of expressing surface CCR5 prior to cognate Ag-induced TCR signaling in inflamed lymph nodes; however, the molecular mechanisms have not been characterized to date. In this study, we show that CCR5, the receptor for CCL3 and CCL4, can be transiently upregulated on a subset of naive CD8(+) T cells and that this upregulation is dependent on direct contact with the high endothelial venule in inflamed lymph node. Binding of CD62L and CD11a on T...

Research paper thumbnail of Intravital Imaging of the Mouse Popliteal Lymph Node

Lymph nodes (LNs) are secondary lymphoid organs, which are strategically located throughout the b... more Lymph nodes (LNs) are secondary lymphoid organs, which are strategically located throughout the body to allow for trapping and presentation of foreign antigens from peripheral tissues to prime the adaptive immune response. Juxtaposed between innate and adaptive immune responses, the LN is an ideal site to study immune cell interactions 1,2. Lymphocytes (T cells, B cells and NK cells), dendritic cells (DCs), and macrophages comprise the bulk of bone marrow-derived cellular elements of the LN. These cells are strategically positioned in the LN to allow efficient surveillance of self antigens and potential foreign antigens 3-5. The process by which lymphocytes successfully encounter cognate antigens is a subject of intense investigation in recent years, and involves an integration of molecular contacts including antigen receptors, adhesion molecules, chemokines, and stromal structures such as the fibro-reticular network 2,6-12. Prior to the development of high-resolution real-time fluorescent in vivo imaging, investigators relied on static imaging, which only offers answers regarding morphology, position, and architecture. While these questions are fundamental in our understanding of immune cell behavior, the limitations intrinsic with this technique does not permit analysis to decipher lymphocyte trafficking and environmental clues that affect dynamic cell behavior. Recently, the development of intravital two-photon laser scanning microscopy (2P-LSM) has allowed investigators to view the dynamic movements and interactions of individual cells within live LNs in situ 12-16. In particular, we and others have applied this technique to image cellular behavior and interactions within the popliteal LN, where its compact, dense nature offers the advantage of multiplex data acquisition over a large tissue area with diverse tissue sub-structures 11,17-18. It is important to note that this technique offers added benefits over explanted tissue imaging techniques, which require disruption of blood, lymph flow, and ultimately the cellular dynamics of the system. Additionally, explanted tissues have a very limited window of time in which the tissue remains viable for imaging after explant. With proper hydration and monitoring of the animal's environmental conditions, the imaging time can be significantly extended with this intravital technique. Here, we present a detailed method of preparing mouse popliteal LN for the purpose of performing intravital imaging.

Research paper thumbnail of Quantification of lymph node transit times reveals differences in antigen surveillance strategies of naive CD4+ and CD8+ T cells

Proceedings of the National Academy of Sciences, 2012

Research paper thumbnail of Administration of Reconstituted Polyphenol Oil Bodies Efficiently Suppresses Dendritic Cell Inflammatory Pathways and Acute Intestinal Inflammation

PLoS ONE, 2014

Polyphenols are natural compounds capable of interfering with the inflammatory pathways of severa... more Polyphenols are natural compounds capable of interfering with the inflammatory pathways of several in vitro model systems. In this study, we developed a stable and effective strategy to administer polyphenols to treat in vivo models of acute intestinal inflammation. The in vitro suppressive properties of several polyphenols were first tested and compared for dendritic cells (DCs) production of inflammatory cytokines. A combination of the polyphenols, quercetin and piperine, were then encapsulated into reconstituted oil bodies (OBs) in order to increase their stability. Our results showed that administration of low dose reconstituted polyphenol OBs inhibited LPS-mediated inflammatory cytokine secretion, including IL-6, IL-23, and IL-12, while increasing IL-10 and IL-1Rα production. Mice treated with the polyphenol-containing reconstituted OBs (ROBs) were partially protected from dextran sodium sulfate (DSS)-induced colitis and associated weight loss, while mortality and inflammatory scores revealed an overall anti-inflammatory effect that was likely mediated by impaired DC immune responses. Our study indicates that the administration of reconstituted quercetin and piperine-containing OBs may represent an effective and potent anti-inflammatory strategy to treat acute intestinal inflammation.