Hematopoietic stem cell (HSC) gene therapy for adenosine deaminase (ADA)-deficient severe combined immunodeficiency (SCID) has shown limited clinical efficacy because of the small proportion of engrafted genetically corrected HSCs. We describe an improved protocol for gene transfer into HSCs associated with nonmyeloablative conditioning. This protocol was used in two patients for whom enzyme replacement therapy was not available, which allowed the effect of gene therapy alone to be evaluated. Sustained engraftment of engineered HSCs with differentiation into multiple lineages resulted in increased lymphocyte counts, improved immune functions (including antigen-specific responses), and lower toxic metabolites. Both patients are currently at home and clinically well, with normal growth and development. These results indicate the safety and efficacy of HSC gene therapy combined with nonmyeloablative conditioning for the treatment of SCID.

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Mucuna pruriens seeds have been widely used against snakebite in traditional medicine. The antivenin property of a water extract of seeds was assessed in vivo in mice. The serum of mice treated with extract was tested for its immunological properties. Two proteins of Echis carinatus venom with apparent molecular masses of 25 and 16 kDa were detected by Western blot analysis carried out using IgG of mice immunized with extract or its partially purified protein fractions. By enzymatic in-gel digestion and electrospray ionization-mass spectrometry/mass spectrometry analysis of immunoreactive venom proteins, phospholipase A 2, the most toxic enzyme of snake venom, was identified. These results demonstrate that the observed antivenin activity has an immune mechanism. Antibodies of mice treated with non-lethal doses of venom reacted against some proteins of M. pruriens extract. Proteins of E. carinatus venom and M. pruriens extract have at least one epitope in common as confirmed by immunodiffusion assay.Snakebite is a considerable problem in certain tropical and subtropical countries. According to World Health Organization estimates, 40,000 of 5 million cases of snakebite are fatal. Antivenins obtained from horses treated with snake venom are one of the principal remedies against snakebite. This therapy has the disadvantage that antivenins must be given immediately, and snakebite victims may develop an adverse reaction including anaphylactic shock (1). The use of endogenous plants with a reputation against snakebite is therefore worth considering (2).In preliminary experiments (3, 4) we demonstrated that extract of M. pruriens (MPE), 1 a medicinal plant widely used in Nigeria for its chemical and pharmacological properties, protects mice against the lethal effect of Echis carinatus venom (EV). Both MPE and EV are heterogeneous mixtures, their interaction represents a complex phenomenon, and there is no information about its biochemical mechanism. EV contains proteins with different toxic properties including opposite effects on blood clotting. Well known proteins are: disintegrins EC3 (5), EC6 (6), and echistatin (7), which inhibit the interaction of fibrinogen with the glycoprotein IIb-IIIa receptor on the platelet surface; echicetin (8) and ECLVIX/Xbp (9) with an opposite effect on platelet aggregation; two metalloproteases, ecarin (10, 11) and carinactivase (12), which are prothrombin activators and act as procoagulant enzymes; and phospholipase A 2 (PLA 2 ) (13-15), the most abundant enzyme, which has many effects including inhibition of prothrombin activation by ecarin and carinactivase (16). When injected into mice, this complex mixture of proteins induces disseminated intravascular coagulation leading to death in less than a day. The composition of the M. pruriens seed is also complex and variable, with 20 -30% protein (lectins, globulins, protease inhibitors), 1-10% fat, 4 -5% ash, 4 -9% water, 4 -7% fiber (17-20), and L-DOPA (21), an interesting non-protein component. The aim of the present study was to stud...

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Adenosine is known to be associated with effects such as inhibition of immune response, coronary vasodilation, stimulation of angiogenesis, and inhibition of inflammatory reactions. Some authors suggest that adenosine may also have similar functions in tumor tissues. Tissue levels of adenosine are under close regulation by different enzymes acting at different levels. Adenosine is produced from AMP by the action of 5'-nucleotidase (5'-NT) and is converted back into AMP by adenosine kinase (AK) or into inosine by adenosine deaminase (ADA). Inosine is converted into purine catabolites by purine nucleoside phosphorylase (PNP), whereas AMP is converted into ADP and ATP by adenylate kinase (MK). The aim of this study was to analyze the activities of the above enzymes in fragments of neoplastic and apparently normal mucosa, obtained less than 5 cm and at least 10 cm from tumors, in 40 patients with colorectal cancer. The results showed much higher activities of ADA, AK, 5'-NT, and PNP in tumor tissue than in neighboring mucosa (p > 0.01 for ADA, AK, and PNP; p > 0.05 for 5'-NT), suggesting that the activities of purine metabolizing enzymes increase to cope with accelerated purine metabolism in cancerous tissue. The simultaneous increase in ADA and 5'-NT activities might be a physiological attempt by cancer cells to provide more substrate to accelerate salvage pathway activity.