TABLE 1.

Neutralization of HIV-1 by CD4i antibodies and antibody fragments (standard neutralization assay A)

MAbFormatNeutralization (IC50 [nM])a of HIV-1 isolate
JR-CSF R5JRFL R5ADA R589.6 X4HxB2 X4
X5IgG1,7991,950>2,000 (14)3478.1
Fab458955>2,000 (33)75974
scFv22411544719116
17bIgG>2,000 (22)>2,000 (20)>2,000 (32)18921
Fab9122881,77824243
scFv15833144712261
48dIgG>2,000 (41)NT1,3804578.7
Fab1,698NT>2,000 (32)>2,000 (36)39
  • a Neutralization was assessed on U87.CD4 cells expressing either the CCR5 (R5) or the CXCR4 (X4) coreceptor. The neutralization of the dual-tropic isolate 89.6 was studied on U87.CD4 cells expressing CXCR4. Where 50% neutralization was not achieved, the percent inhibition at the highest antibody concentration is given in parentheses. IC50, concentration of antibody causing a 50% reduction in viral infection; NT, not tested.