TABLE 2.

Characterization of a panel of human MAbs for their capacities to neutralize human and zoonotic SARS-CoV strains and to inhibit the binding of the SARS-CoV S glycoprotein to human ACE2a

GroupMAb50% Neutralization titer (ng/ml)b for the indicated virusInhibition of SARS-CoV S binding to ACE-2c
HumanZoonoticNeutralization escape variant% InhibitionIC50 (ng/ml)
Late (Urbani)Middle (CUHK-W1)Early (GZ02)Palm civet (HC/SZ/61/03)Raccoon dog (A031G)GZ02-109-1GZ02-109-2GZ02-230
IS1321,984NTNTNT602,570
S228.11196NTNTNT97598
IIS111.71541,232NTNTNT961,208
S224.171941,552NTNTNT98297
IIIS3.145180720NTNTNT96868
S127.665259518NTNTNT97876
S217.43059118NTNTNT99114
S222.151202808NTNTNT9898
S237.186734NTNTNT9766
IVS110.4813226441,288NTNTNT99476
S218.9311232461,968NTNTNT101280
S223.42079158316NTNTNT99112
S225.129187272NTNTNT9968
S226.102390360180NTNTNT9992
S231.1918711412,256NTNTNT99120
S232.17901803602,880NTNTNT10095
S234.6642,032254254NTNTNT100142
VS124.51,4005,6001,1205,600NTNTNT564,700
S219.2248992496NTNTNT44>3,000
VIS109.84248483,392424533,30085525
S215.17251002004003,200NTNTNT98200
S227.14197715330677150150150100126
S230.152040160160801551559984
  • a A panel of 23 human mAbs was tested for their capacities to neutralize recombina NT SARS-CoV S glycoprotein variants (Urbani, CUHK-W1, GZ02, HC/SZ/61/03, and A031G) and neutralization escape variants (GZ02-109-1, GZ02-109-2, and GZ02-230). MAbs are ranked in six groups according to their capacities to neutralize different SARS-CoV S glycoprotein variants.

  • b MAb concentration at which 50% of the viruses are neutralized. −, no neutralizing titer detected at 10 μg/ml; NT, not tested.

  • c The percentage of maximal inhibition by each MAb of SARS-CoV S glycoprotein binding to human ACE2 expressed by murine DBT cells is shown, along with the concentration at which 50% of the binding is blocked (IC50).