Allegretta Bio

hprt Reporter Gene Mutation - Type 1 diabetes mellitus
Dr. Allegretta's research group is studying a reporter gene approach to probe normal and pathological immune responses. Since mutation occurs preferentially in dividing cells, isolating T cells with mutations in the hprt gene will enrich the population for cells of in vivo functional relevance. This approach has been used to detect T cells with pathogenic function in multiple sclerosis, rheumatoid arthritis and systemic lupus erythematosus. We are currently studying individuals at risk for type 1 diabetes mellitus (T1DM). Individuals at risk for developing T1DM can be identified by HLA haplotype, presence of autoantibodies to GAD65 and insulin, and the presence of a sibling with the disease. Because the destructive autoimmune response against the pancreatic beta cell is indolent, by the time overt diabetes develops, the majority of the beta cell mass has been destroyed. We are using the reporter gene approach to detect the early stages of T cell reactivity to pancreatic antigens, with the hope that those individuals might be treated before complete beta cell destruction ensues. The research is sponsored by the Juvenile Diabetes Foundation.

hprt Reporter Gene Mutation - detection of sub-clinical leukemia
Human T lymphotropic virus -1 (HTLV-1) is a virus that causes an aggressive cancer called adult T cell leukemia (ATL). The virus is endemic throughout Japan, with certain regions of the country having elevated prevalence rates. For example, in the Nagasaki Prefecture, (population: 1.5 million), prevalence of HTLV-1 carriers is approximately 10% in the age group over 40 years old. The national average is approximately 1%. Because such a large number of people are carriers of this potentially devastating virus, developing an effective measure to control the endemic cycle of HTLV-1 has been imperative. This is especially important since practical ways to prevent or control ATL are not available.

The primary objective of this project is to determine if the reporter gene selection technology can be used as a diagnostic tool for detection of leukemogenesis in HTLV-1 carriers. The application would be to the test for monoclonal HTLV-1 integration within hprt mutant cells, in order to identify outgrowth of a leukemic T cell clone before it can be detected by current clinical methods. Such a test might allow preventive therapy to be initiated before ATL has progressed to a more aggressive and untreatable state.

In a related collaborative effort with Dr. Richard Albertini, we are testing T cell clones from these individuals for evidence of a mutator phenotype. Many studies have shown that HTLV-1 leukemogenesis is in part mediated by the viral Tax protein. This transcriptional activator also increases genetic instability in infected cells by limiting DNA repair, and it contributes to proliferative hypermutability by causing extensive antigen-nonspecific T cell proliferation. Advances in the methodology developed through this work may be ultimately applied to the detection of pre-clinical disease in B cell leukemia/lymphoma, which are more common hematologic malignancies in humans.

We are also developing other clinical applications of this technology at our biotechnology startup, BioMosaics. Studies are underway to convert the hprt mutation cloning assay to a rapid automated format, and to apply the test in a variety of clinical settings.