Current Research and Scholarly Interests
The focus of my laboratory is defining the immune response to viral vaccines evaluating the ontogeny of responses in infants and limitations in immunocompromised hosts. We have studied the memory effector T cells response in infants given an early two-dose measles vaccine regimen, measuring CD4+, CD4+CD45RO+ and CD4+CD45RO+CCR7-T cells that produce IFN?;. We have also analyzed key markers of activation, using cell surface markers CD69 and CD40-ligand. In addition, we have studied innate immunity and the interactions with the adaptive immune system. We have measured dendritic cell and monocyte populations and function in infants and children and the effects on measles-specific CD4+ T cell responses. These analyses have also been applied to both term and preterm infants receiving polio vaccine, and children receiving varicella vaccination. Our findings have revealed relative limitations in both the innate and adaptive immune system of healthy infants and children as compared with adults. Currently, we are investigating mechanisms responsible for these restrictions. We are also examining the acquisition and persistence of viral immunity in two immunocompromised states, HIV infection and transplantation. The goals of these studies are to define immune profiles in populations where obstacles to vaccination exist to offer insights for the development of novel vaccine strategies.
In my role as Co-director of the Pediatric Infectious Diseases Program for Immunocompromised Hosts I am involved with research related to these populations, including outcome studies, epidemiologic studies focusing on respiratory illness in solid organ transplant, fever and neutropenia in Oncology, and risk factors for Post-transplant Lymphoproliferative Disease and cytomegalovirus disease in transplant recipients. In addition, we are studying the efficacy of vaccines and prophylactic measures, such as synagis, in these populations.