<p>03698 Increasing Expression of CXCR4 in GHOST cells for Biological and Structural Studies of HIV-1 Hannah Oh Mentor: David Camerini</p><p>HIV-1 enters cells by binding to CD4 receptors on T cells, macrophages, and dendritic cells. The virus needs the help of other coreceptors (chemokine receptors) to fuse with the cell membrane. CXCR4 is one of the main coreceptors used by many isolates of HIV-1 during cell entry. CXCR4 is also the receptor for the chemokine CXCL16. We built retroviral vectors that express the HIV-1 coreceptor CXCR4 and used them to stably transfect 293GPG cells thereby creating the retroviral vector producer cell line, 293GPG- MFG-CXCR4. We induced production of the vector and concentrated it as well. The vector was then used to create GHOST cell lines, derived from HOS cells, expressing the CXCR4 receptor. After spinfection of GHOST-CXCR4 cells with the vector, they were analyzed for CXCR4 expression using fluorochrome- conjugated monoclonal antibodies directed to CXCR4. FACSCalibur flow cytometric analysis indicated that the expression of CXCR4 receptor was increased by 20 times the original amount after two consecutive spinfections were performed. The GHOST-CXCR42 cell line will be used for further biological and structural studies of HIV-1.</p>