Arizona State University-Tempe Campus

NIH Research Projects · FY 2025 · 2015-05

Project Summary With our ethnically and socioeconomically diverse longitudinal twin study, in this competing continuation we aim to understand the genetic and environmental mechanisms linking sleep and physical health across pubertal development. We also elucidate mechanisms accounting for longitudinal associations between these health processes and both mental health and inflammation in adolescence. Further, we examine a key proximal sociocultural process - daily media use - which is pervasive in the everyday lives of adolescents. With inflammation and mental health problems on the rise among youth, it is imperative that we utilize a well- powered (N=700 twin youth), representative (recruited from birth records), genetically-informed (twin study), longitudinal (followed since infancy with proposed assessments at 12 and 14 years) design to identify risk and resilience processes across the major transition from childhood to adolescence. To date, our results suggest that sleep is linked with cognition and health for genetic rather than environmental reasons (see C1), suggesting that third variables are involved that may vary by development (puberty). More specifically, we add two follow ups of a diverse twin sample recruited from birth records and assessed at 1, 2, 5, 8, 9, 10 & 11 years (N=700 youth; Arizona Twin Project). At 12 years, we add new assessments of the environment (e.g. media use) and extend our objective measures of sleep and health (aerobic, muscular, adiposity, physiology). At age 14, we add new outcome assessments (inflammatory biomarkers, mental health). Under Aim 1, we use parallel process growth models from childhood into adolescence to determine direction of effects among puberty, sleep, and multiple indicators of health. Under Aim 2, we dynamically extend this work by using intercepts and growth parameters from the parallel process growth models outlined in Aim 1 to predict inflammation and mental health at age 14. Under Aim 3, we examine the genetic and environmental overlap among puberty, sleep, and health and pinpoint aspects of the environment that play a role in health. Such an examination is critical as our work has shown that common risk factors and health are often associated for genetic as opposed to environmental reasons which can shift the focus of potential interventions. Under Aim 4, we disentangle genetic and environmental contributions to associations between daily sociocultural contexts, sleep and health. The proposed study builds on existing collaborations with complementary expertise. The project is notable as it is the only twin sample of youth to obtain longitudinal objective sleep, health, and sociocultural context data, for its developmental cultural and genetic approach that uncovers gene-environment interplay, measurement of physiological and inflammation biomarkers, and examination of proximal sociocultural processes including objective media use in adolescence. Combining these design features exponentially increases the scientific contribution, elucidating processes that support preventive intervention efforts.

NIH Research Projects · FY 2024 · 2012-05

Much of what we know about poxvirus innate immune evasion comes from work with the prototype orthopoxvirus, vaccinia virus (VACV). However, it is becoming clear that what we know for VACV is not always true for other poxviruses. The example we have been working on is monkeypox virus (MPXV). VACV has an E3L gene, which is essential for interferon-resistance, both in cells in culture and in the animal model. Despite being highly pathogenic, MPXV is missing 37 residues from the N-terminus of its E3 homologue. Thus, it is surprising that MPXV is as pathogenic as it is, despite missing this essential region of the E3 innate immune evasion protein. We have shown that while the lack of an N-terminal innate immune evasion domain in MPXV allows the virus to be sensed by the host, MPXV has evolved at least two apparently independent mechanisms to overcome the effects of being sensed in cells. The goals of this research are to understand how this unique human pathogen is sensed in infected cells and how it has evolved to counter the effects of sensing. Loss of this innate immune evasion domain makes vaccination against MPXV problematic. The final goal of this project is to develop a vaccine that can safely protect against MPXV infection.

NIH Research Projects · FY 2025 · 2009-03

In this proposal we will uncover the fundamental mechanisms by which cellular factors of the RNA helicase superfamily and virus encoded host range factors modulate each other’s function, which is key for virus-host interactions, innate immunity, cellular transformation and use of oncolytic viruses for cancer treatment. Myxoma virus (MYXV) is a rabbit specific poxvirus that also exhibits the capacity to infect a wide spectrum of human cancer and transformed cells. MYXV is currently being developed as an oncolytic virotherapeutic to treat various classes of cancer. We have recently reported the identification of members of cellular DEAD-box containing RNA helicases that tightly regulate the tropism of MYXV in human cancer cells. One of our goals is to discover the novel virus-host interactions and dissect the pro- vs anti-viral functions of selected key RNA helicases in human cells. In addition, we discovered that blocking the exportin1-nuclear export pathway not only enhances viral replication but also synergistically promotes killing of human cancer cells without affecting normal human cells. Our goal is to study the in vitro and in vivo impact of this nuclear export pathway in MYXV oncolytic virotherapy. We will continue our effort on understanding the function of two key MYXV host range proteins M029 and M-T5. M029 is a member of the poxvirus E3 family of dsRNA Binding Domain (dsRBD) containing proteins, which modulates the functions of key anti-viral RNA helicases such as DHX9 and PKR in human cancer cells. M-T5 is a member of the ANK family of proteins, and our new preliminary data suggests that M-T5 is required for the enhanced MYXV replication in human cancer cells when nuclear export pathway is inhibited. Thus, our goal is to further understand the host range and immune regulatory functions of M029 and M-T5. Based on our observations we propose to investigate the followings: 1. Elucidate the role of select RNA helicases in MYXV replication and cellular tropism. We propose to investigate the anti-viral and pro-viral functions of key cellular RNA helicases that regulate MYXV tropism in human cancer cells and primary immune cells. 2. Investigate the role of M029 in cellular tropism and innate immune responses. We will dissect the molecular mechanisms by which M029 modulates different cellular pathways in cancer and innate immune cells that depend upon nuclear/cytoplasmic shuttling of host restriction factors. We will identify additional M029 and host interactions and dissect the mechanisms by which the M029 interacting proteins DHX9 and PKR regulate MYXV tropism and oncolysis of human cancer cells. 3. Investigate how combination of nuclear export inhibitor and oncolytic MYXV enhances virus replication, cancer cell killing, and oncolytic virotherapy. We will perform in vitro and in vivo studies to understand the mechanisms how inhibition of nuclear export pathway enhances MYXV replication and oncolytic activity in cancer cell, where MYXV replication is restricted. Additionally, we will investigate the role of MYXV-encoded ANK protein M-T5, which is required for this enhanced virus replication when nuclear export pathway is restricted.

NIH Research Projects · FY 2025 · 1999-07

PROJECT SUMMARY Macrophage fusion resulting in the formation of multinucleated giant cells (MGCs) accompanies a variety of disorders associated with chronic inflammation, including the foreign body response (FBR) elicited by implanted biomaterials. MGCs are a major factor contributing to long-term failures in human vascular prosthetic grafts, pacemaker leads, and other implanted medical devices. Despite the long history of research, the molecular and cellular mechanisms of macrophage fusion and, generally, cell-to-cell fusion remain poorly understood. During the current funding period, we have shown that fibrin polymer, but not its precursor, fibrinogen, deposited on the surface of implanted biomaterials, drives macrophage fusion. Our preliminary in vitro studies found that fibrinogen deposited on the surface at its physiological concentration does not support macrophage fusion, consistent with our previous findings that, upon contact with various surfaces, fibrinogen undergoes self-assembly forming nonadhesive soft matrices. Surprisingly, although the three-dimensional (3D) fibrin gel supports adhesion, it does not support fusion. However, removing the gel, leaving a "2D footprint" consisting of fibrils attached to the rigid surface, restores macrophage fusion. We hypothesize that adsorbed fibrinogen and deposited fibrin polymer form matrices with different mechanical properties and surface patterns, which macrophages sense, initiating different mechanotransduction responses. Specific Aim 1 is to determine why and how the fibrin polymer drives macrophage fusion during the foreign body reaction to implanted biomaterials. Using cell signaling assays with mechanosensitive molecules, ultrastructural studies, the hydrogels with different stiffness, and micropatterned surfaces, we will examine differential sensing by macrophages of the mechanical properties of 3D and 2D matrices prepared from wild-type and mutant fibrin(ogens) and characterize their architectural features. The knowledge obtained will be translated into generating biomaterials with a reduced ability to support macrophage fusion and testing their properties in vivo bioimplant models. Specific Aim 2 will determine the cellular and molecular organization of the macrophage fusion site. Following our finding that macrophage fusion is initiated by an actin-based protrusion and some preliminary data, we hypothesize that a strong actin-propelled protrusion is formed at the leading edge of a donor macrophage enriched in podosomes and situated within the interface restricted by zipper-forming proteins. Taking advantage of our methodological platform consisting of high-resolution microscopy, live cell imaging, mice with myeloid cell-specific knockouts, and macrophages with knockdowns of selected regulators of branched actin network, we will determine the cellular and molecular determinants of the fusion site and fusion pore formation. Overalls, these studies will define the novel biology of macrophage fusion and characterize new mechanisms that have the potential to modulate the FBR.