7. AIDS: Acquired Immunodeficiency Syndrome Collection of symptoms and infections caused by specific damage to the immune system Caused by Human Immunodeficiency Virus Single Stranded RNA Virus (retroviridae) Stage I: asymptomatic Stage II: Minor mucocutaneous manifestations and recurrent upper respiratory tract infections Stage III: includes unexplained chronic diarrhea for longer than a month, severe bacterial infections and pulmonary tuberculosis Stage IV: includes toxoplasmosis of the brain, candidiasis of the esophagus, trachea, bronchi or lungs and Kaposi's sarcoma
12. Bone Marrow Abnormalities of HIV-1 Infected Patients Suppression of cell growth in the bone marrow (Moses A, Nelson J, Bagby G., 1998) Infection of accessory cells (macrophages, microvascular endothelial cells) result in impairment of the HSC growth network Unable to directly infect hematopoietic stem cells due to: High expression of fas-l and cytokines (ifn-g) inhibits viral invasion of HSC’s (Maciejewski J, Selleri C, Anderson S, Young NS, 1995) A consequence is also a high rate of apoptosis in hematopoietic stem cells (G. Zauli and S. Capitani, 1996) .
21. Rationale of the Therapeutic Approach The main pathology of AIDS is immunodeficiency Poor prognosis not directly related to virus but opportunistic infection Hematopoietic stem cells are the precursors to all immune cells It has been demonstrated that HSC’s can be stably transfected in Cases where mutations/polymorphisms in CXCR4/CCR5 co-receptors have controlled infection exist (Long Term Nonprogressive HIV patients)
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23. Research Approach Phase I 1. Developing transgenic versions of CXCR4/CCR5 that are HIV-1 impermissible. -Sequence analysis of known medical cases of HIV resistance -Development of a library of mutants in a yeast expression system 2. Efficient transfection system for modification of implanted HSC’s 3. Appropriate animal for model for studying the effects of HIV-1 Phase II Testing for long term non-progression in mice transplanted with modified HSC's using both X4 and R5 viral HIV viral types. Probe for modification conditions that would provide the best clinical outcome for infected animals
24. 1. Proposes the transplantation of Modified Hematopoietic Stem cells 2. Gammaretroviral vector for M87o, which encodes an artificial transmembrane molecule which inhibits fusion mediated uptake of the virus with CD4 cells. 3. Successfully transfected gene into hematopoietic stem cells into NOD-SCID mice and sustained expression for one generation.