Immucillins as Antibiotics for T‐Cell Proliferation and Malaria

Abstract

The genetic deficiency of human PNP causes a specific immunodeficiency by inducing apoptosis in dividing T‐cells. Powerful inhibitors of PNP have been designed from the experimental determination of the transition state structure of PNPs. The Immucillins are transition state analogue inhibitors with K _d values as low as 7 pM. In the presence of deoxyguanosine the Immucillins kill activated human T‐cells but not other cell types. The Immucillins are orally available and of low toxicity to mice. Immucillins also inhibit PNP from Plasmodium falciparum. Parasites cultured in human erythrocytes are killed by purine starvation in the presence of Immucillins and can be rescued by hypoxanthine.

Keywords:

• Purine nucleoside phosphorylase
• Immucillin‐H
• DADMe‐Immucillin‐H
• T‐cell proliferation
• Malaria
• Purine salvage
• Transition state
• Transition state analogues

Notes

^aImmucillin‐H is being developed under the trade name BCX‐1777, see Refs. 4 12 13, and is now called Fovodosine (see Ref. 20).