Emmune, Inc. is a start-up biotechnology company that has a novel approach for treating and preventing HIV infection. We engineered a synthetic antibody from the receptors that HIV uses to infect T cells, CD4 and CCR5. Because this synthetic antibody, known as “eCD4-Ig,” is built from the viral receptor and co-receptor, it recognizes 100% of HIV-1 isolates. A single intramuscular inoculation with an AAV vector expressing eCD4-Ig protected monkeys from multiple intravenous challenges with live virus.