Summary: Human cytomegalovirus (CMV) is a member of the beta herpesvirus family that can cause morbidity and mortality in immuno-compromised individuals. CMV disease can manifest as neuronal defects in infants and is the leading cause of birth defects affecting newborns worldwide. Anti-viral drugs such as ganciclovir and fomivirsen have been approved as anti-CMV drugs. However, these drugs have limitations including poor oral bioavailability, dose-related toxicity and selection of drug resistant viral mutants as well as precluded for use in pregnant women. The main objective of this application is to optimize prophylactic and therapeutic conditions using biologics to inhibit CMV infection and dissemination. We plan to develop and characterize broadly neutralizing CMV human monoclonal antibodies (mAbs) as future therapeutics due to its specificity for viral factors and its safety profile when administered in humans. The ability of CMV to infect multiple cell types such as fibroblasts and endothelial, epithelial, and myeloid cells is essential for viral dissemination and proliferation within the host. We hypothesize that a combinatorial approach using broadly neutralizing CMV mAbs against envelope proteins will provide the basis for effective therapeutics to inhibit CMV entry and dissemination. Our preliminary data and published findings characterizing anti-gH mAbs have demonstrated the effectiveness and specificity of our immunization and screening strategies to identify broadly neutralizing CMV mAbs. Thus, we will evaluate our hypothesis and accomplish our objective by completing the following aims: Aim 1: Identify neutralizing CMV mAbs against viral envelope proteins. A CMV high-throughput infection assay will be employed to identify human mAbs from VelocImmuneTM mice immunized with intact clinical CMV strains. Aim 2: Characterization of broadly neutralizing CMV mAbs that inhibit infection and dissemination. We plan to identify and characterize the CMV mAbs identified from VelocImmuneTM mice as broadly neutralizing mAbs that function as prophylactic and therapeutic agents. Aim 3: Define the mechanism of action of CMV neutralizing mAbs targeting different envelope proteins. We plan to define the inhibitory mechanism of broadly neutralizing mAbs to identify the steps of virus entry amenable to biologic intervention. Aim 4: Determine therapeutic conditions to prevent dissemination in diverse models. We plan to determine the optimal mAb treatment to prevent virus dissemination in cell-based, organoid, and animal models. We expect to optimize human mAb-based therapeutic treatments to inhibit CMV infection and dissemination as a prophylactic and therapeutic strategy to be utilized for patients at high-risk for CMV-associated disorders.

Narrative: Human cytomegalovirus causes a high-rate of morbidity and mortality in newborns, transplant recipients, and other immunocompromised individuals including AIDS patients, and patients with cardiovascular disease and autoimmune diseases. The development of CMV therapeutics effective therapeutics will prevent and treat cytomegalovirus-associated diseases.