Table 5.
Reported residues of antigenic relevance identified with mouse monoclonal and chicken polyclonal antibodies
| Most frequent amino acid residue in naturec | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Residuea | Conservation %b | Antigenic site | American | Y439 | Korean | G1-E | G1-W | BJ94 | Published mAb escape | Impact on chicken antisera | Reference(s) |
| 72 | 82.2 | H9-B | G | G | G | G/E | G | G/E | G-E | G-E | Okamatsu et al. 2008; Peacock et al. 2018 |
| 74 | 73.9 | K | K | K | R | R | R | R-K, R-Gd | R-G | Zhu et al. 2015; Peacock et al. 2018 | |
| 98 | 98.9 | L | L | L | L | L | L | L-Q | – | Okamatsu et al. 2008; Peacock et al. 2018 | |
| 109 | 56.4 | K/S/R | N | R | S | S | R/S | S-R, S-I | – | Kaverin et al. 2004; Peacock et al. 2018 | |
| 115 | 91.5 | H9-B | Q | Q | L | Q | Q | Q/L | Q-P, Q-R, Q-L | Q-P | Peacock et al. 2016, 2018; Jin et al. 2019 |
| 120 | 81.7 | H9-B | T/R | T | R | T/A | T/S | T/S | T-K | – | Peacock et al. 2016, 2018 |
| 121 | 54.6 | I/T | I | T | I | I | I | I-Td | I-T | Peacock et al. 2018 | |
| 127 | 49 | Overlap | S | S | T | T/D | T/S | S/D | S-Ne | T-Ne | Kaverin et al. 2004; Okamatsu et al. 2008; Peacock et al. 2018 |
| 129 | 99.6 | Site I | T | T | T | T | T | T | T-A, T-K | T-K | Kaverin et al. 2004; Peacock et al. 2018 |
| 131 | 84.8 | K/R | K | K | K | K | K/T | K-Ne, K-Id, K-Rd, A-Rd | K-I | Okamatsu et al. 2008; Peacock et al. 2018 | |
| 135 | 62.4 | H9-B/site II | N/D | N | G/N/D | D/G | D | D/G | D-E, D-N, D-Gd | D-G | Kaverin et al. 2004; Wan et al. 2014; Peacock et al. 2018 |
| 137 | 99.8 | F | F | F | F | F | F | F-L | F-L | Kaverin et al. 2004; Peacock et al. 2018 | |
| 139 | 98.9 | H9-B | R | R | R | R | R | R | R-G, R-M | – | Peacock et al. 2016, 2018 |
| 145 | 99.8 | H9-A | T | T | T | T | T | T | T-I | T-I, S-N | Ping et al. 2008; Zhu et al. 2015; Peacock et al. 2016, 2018 |
| 146 | 70.8 | H9-A/site I | H | H | H | Q | Q | Q/R | Q-K | Q-H | Wan et al. 2014; Peacock et al. 2018 |
| 147 | 99.3 | Site I | K | K | K | K | K | K | K-T | – | Kaverin et al. 2004; Wan et al. 2014; Peacock et al. 2018 |
| 148 | 59.9 | Site I | S | S | S | S | N | N/S/D | N-D | N-D | Okamatsu et al. 2008; Zhu et al. 2015; Peacock et al. 2018 |
| 149 | 54.3 | H9-A/site I | N | N | N | G | G | N | N-D, N-K | G-D/K | Wan et al. 2014; Peacock et al. 2018 |
| 150 | 33 | Site I | S | S | S | S/N/F | L/N/F/V/G | A/N/D/E | A-Te, A-D A/N-V/Ld, A-Fd, F-Ld, F-S- Td | A-L/F, L-Se/A | Wan et al. 2014; Peacock et al. 2018 |
| 152 | 99.5 | Site I | P | P | P | P | P | P | P-L | – | Kaverin et al. 2004; Peacock et al. 2018 |
| 162 | 50.6 | H9-B | E/K | E | W | R | R/Q | Q/R | R-W | – | Peacock et al. 2016, 2018 |
| 178 | 95.5 | Site II | D | D | D | D/E | D | D/E | D-V | – | Wan et al. 2014; Peacock et al. 2018 |
| 179 | 93.6 | H9-A/overlap | T | T | T | T | T | T/D | T-A | T-N | Kaverin et al. 2004; Zhu et al. 2015; Peacock et al. 2018 |
| 180 | 46.8 | H9-A | E | E | E | A/E | A/T/V | A/V/T | A-E-Td, A-Vd, E-Dd | A-E | Peacock et al. 2018 |
| 182 | 85.7 | N/T | T | M | T | T | T/R | T-I | T-R | Okamatsu et al. 2008; Peacock et al. 2018 | |
| 183 | 86.8 | H9-A/site II | N/D | N | N | N | N | N/D | N-D, N-S, N-T, N-E/Td | N-T | Kaverin et al. 2004; Okamatsu et al. 2008; Wan et al. 2014; Peacock et al. 2016, 2018 |
| 188 | 75 | Overlap | T/A | A/D | A | T/N | T/N | T | T-Ne | T-Ne | Kaverin et al. 2004; Peacock et al. 2018 |
| 189 | 98.7 | D | D | D | D | D | D | D-Ne | D-Ne | Wan et al. 2014; Peacock et al. 2018; Jin et al. 2019 | |
| 195 | 59.7 | T | T | T | T/A | T | A/T | A-Td | NT | Peacock et al. 2018 | |
| 198 | 46.6 | D | D | D | D/N | N/D | E/D | D-N | – | Peacock et al. 2018 | |
| 200 | 68.6 | N | N | N | N | D | N/D | N-D | N-D | Wan et al. 2014; Jin et al. 2019 | |
| 212 | 96.9 | H9-A | L | L | L/I | L | L | L | L-H, L-P | – | Okamatsu et al. 2008; Peacock et al. 2016, 2018 |
| 216 | 62.3 | Site II | Q | Q | Q | Q/L | L/Q | L/Q | L-Q | L-Q | Kaverin et al. 2004; Peacock et al. 2018 |
| 217 | 55.4 | H9-A | Q | Q | Q | Q | I | Q/M | I-T | I-L/M/Q | Peacock et al. 2016, 2018 |
| 234 | 99.8 | H9-A | R | R | R | R | R | R | R-Q, L-M | – | Peacock et al. 2016, 2018; Jin et al. 2019 |
| 249 | 65.7 | V | I | I | I/V | V/I | I | I-V/Ad | I-V | Peacock et al. 2018 | |
| 264 | 51.4 | N | N | N/K | N/K | N/K/S | K/N | K-Nd | NT | Peacock et al. 2018 | |
| 276 | 83.7 | R/K | K | K | K | K | K/R | K-Rd | NT | Peacock et al. 2018 | |
| 288 | 61.9 | I/V | V | V | I | I/V | V | I-Vd | NT | Peacock et al. 2018 | |
| 306 | 99.3 | K | K | K | K | K | K | I-Kd | NT | Peacock et al. 2018 | |
The most frequent residues at those positions for each H9N2 lineage are reported.
(NT) Not tested.
aAll HA positions follow the H9 numbering. Percent of conservation at selected residues is based on the global avian H9N2 HA1 amino acid alignment of 600 sequences from the analysis in Figure 3 with Scop3D entropy calculation (Vermeire et al. 2015).
bPercent of conservation.
cMost frequent amino acid residue at selected positions based on global H9 phylogenetic analysis of HA1.
dIdentified by integrated modeling of HI titers and gene sequence data.
ePotential glycosylation sites.