RECOMBINANT HUMAN PARAINFLUENZA TYPE 1 VIRUSES (HPIV1S) CONTAINING MUTATIONS IN OR DELETION OF THE C PROTEIN ARE ATTENUATED IN AFRICAN GREEN MONKEYS AND IN CILIATED HUMAN AIRWAY EPITHELIAL CELLS AND ARE POTENTIAL VACCINE CANDIDATES FOR HPIV1

摘要

Two recently characterized live attenuated HPIV1 vaccine candidates, rHPIV1-CR84G/ ?170HNT553ALY942A and rHPIV1-CR84G/? 170HNT553AL? 1710-11, which contain temperature sensitive (ts) attenuating (att) and non-ts att mutations, were evaluated in a Human Airway Epithelium (HAE) model culture system and in vivo in African Green monkeys (AGM). The vaccine candidates were highly restricted in growth in HAE at permissive (32 o C) and restrictive (37 o C) temperatures. The viruses grew slightly better at 37 o C than at 32 oC, and rHPIV1-CR84G/ ?170HNT553ALY942A was less attenuated than rHPIV1-CR84G/ ?170HNT553AL ?1710-11. The level of replication in HAE correlated with that observed in African Green monkeys, suggesting that the HAE model is useful as a tool for pre-clinical evaluation of HPIV1 vaccines. A live attenuated HPIV1 vaccine candidate having a normal P/C gene structure of overlapping P and C open reading frames, but does not express any functional C protein, is found to highly attenuated in AGMs, and provides a significant immune response in AGMs.