further examination of the biochemical proper-
ties and specificities of the naïve Abs. Twenty-
three HMP Fabs bound to N332-GT1 and/or
N332-GT2 by SPR and did not bind detect-
ably to the MD39 native-like trimer, demon-
strating proper N332 glycan supersite epitope
specificity (Fig. 3, E and F). These SPR-
validated epitope-specific clones were highly
enriched for VL3-25, VL3-1, or the closely related
VL3-10 (Fig. 3E). Thus, the protein designstrategy resulted in Envtrimersthatcould
successfully bind human naïve B cells with
BG18-like LCs.
All N332-supersite bnAbs identified to date
require a long HCDR3 [≥20 amino acids (aa)],Steichenet al.,Science 366 , eaax4380 (2019) 6 December 2019 5of13
45N332-GT2 AF647N332-GT2 AF488N332-KO AF568N332-GT2 A4880.05912.479.095.8B220+ GT2++BG18gHWTNon-immunizedVHgenesVLgenes IGKV6-32*01
IGKV4-80*01
IGKV4-79*01
IGKV4-69*01IGKV4-68*01
IGKV4-55*01
IGKV3-4*01
IGKV3-10*01
IGKV4-61*01
IGKV3-5*01
IGKV3-1*01IGKV12-41*01
IGKV4-57-1*01IGKV10-96*01IGKV12-46*01IGKV10-94*01IGKV12-44*014848
20.8%20.9%12.5%10.
5%Frequency of B cells (%)GT2++KO-Day8
post-immunizationDay42
post-immunizationVHgenesVLgenes Tree scale: 0.01GT2 MD390.012.525.0GT2 MD390.000.631.25*
**CD45.2 GT2++KO- CD45.1 GT2++KO-Frequency of B cells [%] Frequency of B cells [%]GC formation CD45.2IgG ED50Immunogen:
GT2GT2KOGT2KOGT2KOGT2KO1×10-11×10^01×10^11×10^21×10^31×10^41×10^5***Immunogen:
MD39051015BG18gH
WT134134Day8
post-immunizationDay42
post-immunizationGT2-AF488 GT2-AF488GT2-AF647 GT2-AF647ELISAGT2 MD390.000.400.80*
**GT2 MD390.000.060.12*
nsIGKV12-41*01
IGKV4-57-1*01IGKV12-46*01
IGKV12-44*01IGHV4-4*02IGHV4-4*0245BCFAHID EGJ K
IC50
(μg/mL)
<0.01
0.01 - 0.1
0.1 - 1
1 - 50
>50BG505_V1modSF162P3_V1 modAC10_V1 mod
AD8_V1modBG505_7mutBG505_MD39N332-GT2_KO1×10^11×10^21×10^31×10^41×10^5KD(nM) d42_iGL
d42naive7mutBG505_MD39N332-GT2_KOd42_iGL
d42naiveKD(nM)Ab BG505 T332N BG505-V1mod
d42.4 >50 3.3
d42.8 >50 0.06
d42.13 >50 1.61
d42.11 >50 0.45
d42.12 >50 0.1
d42.10 >50 ND
d42.iGL1 >50 >50
d42.iGL2 >50 >50
d42.iGL3 >50 >50
d42.iGL4 >50 >50
d42.iGL5 >50 >50
naive1 >50 >50
naive2 >50 >50
naive3 >50 >50
naive4 >50 >50
naive5 >50 >50
BG18 0.005 0.006RESEARCH | RESEARCH ARTICLE
on December 12, 2019^http://science.sciencemag.org/Downloaded from