TABLE 1.
Summary of HobJo screens
| Screenc | Target(s)d | No. of VHHs with indicated specificitya |
TNAb |
||||||
|---|---|---|---|---|---|---|---|---|---|
| A | B | R | Total | +++ | ++ | + | − | ||
| 1 | RTA | 11 | 0 | 0 | 11 | 2 | 2 | 2 | 5 |
| 2 | RTB | 0 | 9 | 0 | 9 | 1 | 0 | 0 | 8 |
| 3 | RTA | 7 | 0 | 0 | 7 | 0 | 2 | 2 | 3 |
| 4 | RTB | 0 | 9 | 0 | 9 | 0 | 0 | 0 | 9 |
| 5 | R-ASF | 5 | 0 | 1 | 6 | 0 | 1 | 1 | 4 |
| 6 | R-PB10 | 5 | 2 | 0 | 7 | 1 | 0 | 1 | 5 |
| 7 | Peptides | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| 8 | RTB-ASF | 0 | 5 | 0 | 5 | 0 | 0 | 1 | 4 |
| 9 | R-F5 + F6 | 4e | 8 | 3 | 15e | 3 | 2 | 0 | 9 |
| Total | 31 | 33 | 4 | 68e | 7 | 7 | 7 | 47 | |
a
A, RTA; B, RTB; R, ricin holotoxin.
b
Toxin neutralizing activity, based on IC50, indicated as follows: +++, IC50 < 10 nM; ++, IC50 < 100 nM; +, IC50 < 500 nM; −, IC50 > 500 nM or undetectable.
c
VHHs in screens 1 and 2 were reported previously (12).
d
R-ASF, ricin captured by ASF; R-PB10, ricin captured by PB10; RTB-ASF, RTB captured by ASF; R-F5 + F6, ricin captured with VHH JIV-F5 and then blocked with excess JIV-F6.
e
One anti-RTA VHH from screen 9 was not successfully expressed and thus was not characterized for TNA and also was not included in the final VHH total of 68.