July 19, 2012

Long antibodies better against HIV

Understanding how antibodies with long “loops” form may be important for HIV vaccine development.

Antibodies that contain a long “loop” in a particular region (HCDR3) of the antibody protein efficiently inhibit a wide variety of pathogens. Some of the most broad and potently neutralizing HIV antibodies have extremely long HCDR3s. Induction of long HCDR3 antibodies may be critical for an effective HIV vaccine, but how to select for or induce such antibodies is unclear.

(Wellcome Images)

To explore how long HCDR3 antibodies are generated, James Crowe Jr., Ingram Professor of Cancer Research, and colleagues examined expressed antibody sequences in human circulating blood samples. They found that antibodies containing long HCDR3s are formed during early genetic recombination events in immune system B cells, not by later genetic insertions during B cell maturation processes. They also identified conserved genetic sequence elements in the long HCDR3 antibody population.

The findings, reported in the May issue of PLoS ONE, could guide strategies for inducing the expansion of particular B cells that encode antibodies with long HCDR3s, which may be important for HIV vaccine development.

This research was supported by a grant (AI078407) and a contract (HHSN272200900047C) from the National Institute of Allergy and Infectious Diseases of the National Institutes of Health, and in part by the Vanderbilt CTSA grant (RR024975) from the National Center for Advancing Translational Sciences of the National Institutes of Health.

Send suggestions for research to highlight in Aliquots to: