In vitro modulation of the toxicity associated with the use of zidovudine on normal murine, human, and murine retrovirus-infected hematopoietic progenitor stem cells with basic fibroblast growth factor and synergistic activity with interleukin-1

Diversity analysis of 14 156 molecules tested by the National Cancer Institute for anti-HIV activity using the quantitative structure-activity relational expert system MCASE

Using the MCASE program, a procedure to analyze the diversity of the large amount of available HIV-1 antiviral data was proposed. A subset of 1 819 chemicals was logically selected from the original 14 156 chemicals tested by NCI. This subset of chemicals was shown to contain most of the structural and the functional information of the original database. A full analysis of the 1 819 chemicals by the MCASE program produced a correlation between chemical structures and HIV antiviral activity. In our model, 74 fragments were identified as being responsible for all the chemical's HIV antiviral activity. These fragments may be related to different inhibiting mechanisms, some known and some probably still unknown. The expert system resulting from this analysis can be used to predict the activity of new chemicals and to design new agents that can target multiple enzymes. This was shown to be the case by using the model to predict the activity of 10 diverse chemicals whose activities were not known at the time of model development. Of these, 8 were predicted in agreement with experimental observations. As far as we can tell, this is probably the first project ever to attempt to create a quantitative model of activity for such a massive database of diverse chemicals.

The tetrapeptide AcSerAspLysPro (Seraspenide), a hematopoietic inhibitor, may reduce the in vitro toxicity of 3'-azido-3'-deoxythymidine to human hematopoietic progenitors

3'-azido-3'-deoxythymidine (AZT), the main antiviral drug used in AIDS treatment, is known to induce anemia and neutropenia. These effects have been attributed to its toxicity to hematopoietic progenitors. In this report, we present a new approach to reduce AZT hematotoxicity by using an inhibitory factor of the hematopoietic stem cells, the tetrapeptide AcSerAspLysPro (AcSDKP, Seraspenide), which has been shown to increase the survival of mice subjected to high doses of chemotherapy and to block reversibly the cycling of human granulocyte-macrophage colony forming unit (CFU-GM) and burst forming unit erythroid (BFU-E) progenitors. Normal bone marrow mononuclear cells (BMMNC) from 14 subjects were incubated with or without AcSDKP (10(-10) M) for 20 h and with or without AZT (100 microM) for another 2 h. After washing, cells were plated in methylcellulose in the presence of interleukin 3 (IL-3), granulocyte-macrophage colony stimulating factor (GM-CSF) and erythropoietin (EPO). Under these conditions, the preincubation of cells with AcSDKP reduced significantly the toxicity of AZT to both BFU-E and CFU-GM at least in 3 out of 8 and 4 out of 10 cases, respectively. A careful statistical analysis of these observations indicates that AcSDKP may be an efficient factor in preserving progenitors against AZT-induced hematopoietic toxicity.