Volume 12, Number 6—June 2006
Perspective
Host Range Restriction and Pathogenicity in the Context of Influenza Pandemic
Table
Comparison of the hemagglutinin (HA) cleavage sites of highly pathogenic avian influenza viruses and their nonpathogenic predecessors
| Isolate | Type | Amino acid sequence* | Reference |
|---|---|---|---|
| A/chicken/Pennsylvania/1/83 (H5N2) | Avirulent | P Q - - - - - - - - - - - K K K R/ G L F | (36) |
| A/chicken/Pennsylvania/1370/83 (H5N2) | Virulent | P Q - - - - - - - - - - - K K K R/ G L F† | (36) |
| A/chicken/Mexico/31381-7/94 (H5N2) | Avirulent | P Q - - - - - - - - - - - R E T R/ G L F | (37) |
| A/chicken/Queretaro/14588-19/95 (H5N2) | Virulent | P Q - - - - - - - - - R K R K T R/ G L F | (37) |
| A/turkey/Italy/99 (H7N1) consensus | Avirulent | P E I P K G - - - - - - - - - - R/ G L F | (38) |
| A/turkey/Italy/99 (H7N1) consensus | Virulent | P E I P K G - - - - - - S R V R R/ G L F | (38) |
| A/chicken/Chile/176822/02 (H7N3) | Avirulent | P E K P K - - - - - - - - - - T R/ G L F | (39) |
| A/chicken/Chile/4957/02 (H7N3) | Virulent | P E K P K T C S P L S R C R K T R/ G L F | (39) |
| A/chicken/Chile/4322/02 (H7N3) | Virulent | P E K P K T C S P L S R C R E T R/ G L F | (39) |
| Isolate CN6/04 | Avirulent | P E N P K - - - - - - - - - - T R/ G L F | (40) |
| A/chicken/BC/CN12/04(H7N3) | Virulent | P E N P K - - --Q A Y Q K R M T R/ G L F | (40) |
| A/chicken/BC/NS1337-1/04 (H7N3) | Virulent | P E N P K - - - Q A Y K K R M T R/ G L F | (40) |
| A/chicken/BC/NS-1319-2/04(H7N3) | Virulent | P E N P K - - - Q A Y H K R M T R/ G L F | (40) |
| A/chicken/BC/CN7-3/04 (H7N3) | Virulent | P E N P K - - - Q A Y R K R M T R/ G L F | (40) |
| A/chicken/BC/NS-1390-2/04(H7N3) | Virulent | P E N P K - - - Q A H Q K R M T R/ G L F | (40) |
| A/chicken/BC/NS-2035-12/04(H7N3) | Virulent | P E N P K - - - Q A C Q K R M T R/ G L F | (40) |
*HA cleavage sites are indicated by /. For sequence variants, the amino acids that differ from most sequences found are underlined.
†HA cleavability was enhanced by a single amino acid substitution that abrogated glycosylation near the HA cleavage site.


