HPD Research Day | February 16, 2018

24 Terry, Jonas, and Finkelstein Auditoriums Terry, Jonas, and Finkelstein Auditoriums 10:45 – 11:15 a.m. Autophagy-Mediated Immunoregulatory Properties of MIAMI Cells Vladimir Beljanski, Ph.D., Assistant Professor, College of Allopathic Medicine, Nova Southeastern University Fiorella Rossi, Center for Collaborative Research, Nova Southeastern University Mesenchymal stromal cells (MSCs) are frequently used in tissue regeneration as they can be easily isolated and expanded; they maintain progenitor properties, possess a capacity to differentiate into specific cell types, and secrete soluble factors that facilitate regeneration of damaged tissues by multiple mechanisms, including immunomodulation. Immunomodulatory properties of MSCs are associated with their ability to 1) secrete soluble factors upon sensing an inflammatory environment and 2) engage in cell-cell contact with immune cells. Autophagy is a lysosomal-dependent catabolic stress-response mechanism that is upregulated in response to a variety of “stressors” such as starvation, growth factor deprivation, endoplasmic reticulum stress, and/or pathogen infection. Autophagy regulates antigen presentation, cytokine secretion and also secretion of soluble factors. Therefore, we hypothesize that autophagy may be involved in regulating MSCs’ immunomodulatory properties. To test this hypothesis, we utilized a subtype of MSCs called “marrow-isolated adult multilineage inducible” (MIAMI) cells due to their ease of isolation from bone marrow, high differentiation capacity, as well as their immunomodulatory and tissue repair capacities. To enhance MIAMI cells immune-regulatory properties, we pre-treated them with IFN- gamma and, at the same time, treated them with autophagy stimulator or inhibitor drugs. MIAMI cells were exposed to 500U/ml IFN-gamma alone or together with 5µM Tamoxifen (an autophagy stimulator), or 10µM of Chloroquine (an autophagy inhibitor) for 4 days. The cells were subjected to RNA sequencing (RNA-seq) to determine the effects of autophagy modulation on global gene expression. In addition to RNA-seq, we are also evaluating changes in expression of regulatory microRNAs in these cells. Furthermore, preliminary results using co-culture assays suggest that MIAMI cells increase CD4+ T cells regulatory phenotype indicated by the increase in T cell regulatory markers (CD4+CD25+CD127+). Altogether, this project will contribute to development of novel therapeutic approaches where modulation of autophagy may be used to modify therapeutic properties of MIAMI cells. Videoconferencing: Broadcast from Jonas Auditorium to regional campuses, and Terry and Finkelstein Auditoriums. Terry, Jonas, and Finkelstein Auditoriums 11:15 – 11:45 a.m. Dendritic Cell Gene Expression and CD4 T Cell Viral Reservoirs in HIV Infections Travis Craddock, Ph.D., Associate Director/Assistant Professor, College of Allopathic Medicine, Nova Southeastern University Gordon Broderick, Ph.D., Center for Clinical Systems Biology, Rochester General Hospital Mario Stevenson, Ph.D., Leonard M. Miller School of Medicine, University of Miami Shannon Murray, Ph.D., College of Allopathic Medicine, Cell Therapy Institute, Nova Southeastern University Objective. To determine whether gene expression in myeloid dendritic cells (mDC) is correlated to the size of the human immunodeficiency virus (HIV) reservoir in CD4 T cells during antiretroviral therapy (ART)-treated HIV infections. Background. mDC are innate immune cells that respond to viral infections. One barrier to curing HIV infections is the existence of latent reservoirs after HIV integrates into the genome of CD4 T cells. There is a critical need to examine the role of mDC in viral reservoir maintenance to inform strategies to counteract HIV latency. Methods. We will quantify the HIV reservoir in CD4 T cells and assess the gene expression of mDCs from successfully ART-treated (ST) individuals. Using these data, we will develop a computational approach to model the relationship between mDC gene expression and the size of HIV reservoirs in CD4 T cells. Results. We identified genes and pathways in mDC that correlated with HIV reservoir levels in CD4 T cells, which differed depending on treatment status. We anticipate that a larger cohort of ST subjects will enable the further identification of genes and pathways of mDC that correlate with HIV reservoir levels. Conclusion. These results will inform targets for the control or elimination of latent reservoirs in HIV curative approaches. This work has the potential to identify new biomarkers for determining reservoir size and inform strategies such as DC vaccination regimes for eradicating viral