Summary Human antibodies to HIV-1 can neutralize a broad range of viral isolates in vitro and protect non-human primates against infection1,2. Previous work showed that antibodies exert selective pressure on the virus but escape variants emerge within a short period of time3,4. However, these experiments were performed before the recent discovery of more potent anti-HIV-1 antibodies and their improvement by structure-based design5-9. Here we re-examine passive antibody transfer as a therapeutic modality in HIV-1-infected humanized mice (hu-mice). Although HIV-1 can escape from antibody monotherapy, combinations of broadly neutralizing antibodies (bNAbs) can effectively control HIV-1 infection and suppress viral load to levels below detection. Moreover, in contrast to antiretroviral therapy (ART)10-12, the longer half-life of antibodies led to viremic control for an average of 60 days after cessation of therapy. Thus, combinations of potent monoclonal antibodies can effectively control HIV-1 replication in hu-mice, and should be re-examined as a therapeutic modality in HIV-1-infected individuals.

Antibodies to double-stranded DNA are pathognomonic of systemic lupus erythematosus and deposit in the kidneys of lupus patients to cause glomerulonephritis. Recent data suggest that a significant proportion of anti-DNA antibodies may cross-react with renal antigens and be sequestered in the kidney by virtue of this cross-reactivity. If this is true, antigenic competition for pathogenic antibodies might prevent their deposition in kidneys and the ensuing tissue damage. To generate surrogate antigens that could be used for this purpose, we have used peptide display phage libraries to identify peptides that react with R4A, a pathogenic mouse monoclonal anti-DNA antibody that deposits in glomeruli. We have demonstrated that the peptides bind in or near the double-stranded DNA binding site. Furthermore, the peptides are bound preferentially by the R4A antibody as compared with two closely related antibodies derived from it, one of which deposits in renal tubules and one of which displays no renal pathogenicity. Administration of one of these peptides in a soluble form protects mice from renal deposition of the R4A anti-DNA antibody in vivo. This represents a new therapeutic approach in systemic lupus erythematosus that focuses on protecting target organs from antibody mediated injury.

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