Request Expert

Expert has been involved in numerous animal studies examining various aspects of infectious disease agents. Expert has worked with animal models of infection with the following diverse pathogens: Schistosoma mansoni, Candida albicans, Borrelia burgdorferi, and S. aureus. In addition, he has been a part of vaccine design studies aimed at developing vaccine formulations for the preventions of Lyme disease (B. burgdorferi) and S. aureus infections. The findings of these studies have been published in peer-reviewed journals and can be found on routine Pub-Med searches.

Expert was the lead investigator on a CDC-sponsored project to explore candidate antigens for the development of a Second Generation Lyme vaccine. The results from this study have been published in the journal Vaccine. Currently, Expert is involved in a research project aimed at developing a vaccine that can be used to protect against methicillin-resistant S. aureus-induced pneumonia. Both of these research projects involved mouse models of disease. In both models of disease, cellular and humoral responses were measured using ELISA-type assays and measuring the delayed-type hypersensitivity responses to specific antigens following immunization or infection.

Expert has experience with several bacterial models of disease. His early work involved examining the role of ultraviolet radiation (a known immunosuppressant) on bacterial dissemination. Specifically this work was done using the Lyme spirochete Borrelia burgdorferi. He later used the primary disease manifestations caused by this pathogen (arthritis) as a read out for vaccine efficacy in projects developing novel vaccines for the prevention of disease. Expert has used various models of disease to study the mechanisms of immune evasion employed by S. aureus and is currently involved with vaccine research related to preventing staphylococcal disease.

Many disease manifestations resulting from S. aureus infections are a function of toxins produced by this organism. One toxin in particular called the Panton Valentine leukocidin is associated with the methicillin-resistant strains of S. aureus responsible for the current epidemic that primarily affects otherwise healthy children. Expert was part of a team that developed a mouse model to study the effects of this toxin in the development of necrotizing pneumonia. These results are published in Science magazine (2007).

Expert’s doctoral work explored the effects of ultraviolet radiation on various immune functions. Ultraviolet radiation is a known immunosuppressant that can suppress both humoral and cellular responses including contact and delayed-type hypersensitivity. Expert used suppression of CHS and DTH in various capacities during his graduate career and understands the effector mechanisms associated with both hypersensitivity responses.

The enzyme-linked immunosorbent assay (ELISA) has been a technique used by Expert in various capacities for over 20 years. ELISA assays were used and are currently being used to assess the type of immune response that develops to various antigens following either infection or immunization.

Expert has been involved in various vaccine studies aimed at developing formulations that can protect against Borrelia burgdorferi (the Lyme spirochete) or Staphylococcus aureus, respectively. For each study, recombinant proteins were used as vaccinogens. The genes to each recombinant protein used in the vaccine studies were cloned into respective expression vectors and the proteins generated from this process were purified using affinity chromatography and used in the vaccination experiments. For the different studies, various adjuvants were used to stimulate the immune response depending on the route of vaccination. Intraperitoneal vaccinations included vaccine candidates emulsified with either Freund’s complete and incomplete adjuvant, alum, or titermax and intranasal vaccinations were done using Cholera toxin as an adjuvant.

Pathogens use various strategies to escape immune recognition. One common strategy is immunomodulation of humoral or cellular responses (or both). Expert has researched immunomodulation in S. aureus for several years. Specifically, he has shown that the S. aureus Map protein (MHC class II analog protein) can inhibit T cell-mediated responses (delayed-type hypersensitivity) and the Efb protein (Extracellular fibrinogen-binding protein) can inhibit complement-mediated lysis. Both of these proteins are the subject current patent applications that propose the use of these proteins as modulators of the immune response in the context of certain autoimmune diseases.

Expert spent several years working with the trematode Schistosoma mansoni. This helminth is second only to Malaria as a cause of morbidity and mortality in endemic regions and infections begin through the skin and after several weeks adult worms live in the hepatic portal system laying eggs that get lodged in the microvasculature causing tissue destruction. Using ultraviolet radiation (an immunosuppressant that can destroy immune cell in the skin), Expert explored the role of the cutaneous immune system on S. mansoni infections.