Monoclonal antibodies to p24-core protein of HIV-1 mediate ADCC and inhibit virus spread in vitro.
BACKGROUND
Certain antigens of the HIV-1, e.g., gp120-envelop proteins, can be expressed on the membrane of HIV-infected cells. Little is known about the membrane expression of other HIV-antigens and their interaction with specific antibodies.


OBJECTIVE
To develop murine monoclonal antibodies (mAbs) to the p24-core protein of HIV-1 and to characterise their binding sites and biological activities on HIV-infected T cells.


METHODS
Monoclonal antibodies were developed from mice hyperimmunised with a recombinant p24-core protein from HIV-1. Two mAbs were epitope-mapped on overlapping peptides and characterised for their reactivity with non-fixed HIV-infected T cells by immunofluorescence staining and flow cytometric analysis. Their biological activities were studied for antibody-dependent cellular cytotoxicity (ADCC) and suppression of viral spread in vitro.


RESULTS
The epitopes of two selected mAbs were located on the amino terminal region of p24 in the regions 147-152 aa and 178-187 aa, respectively. The antibodies were able to react with living HIV-1 infected cells. The expression of the antigens was time-dependent after the infection of certain cell lines by HIV-1. The mAbs mediated a strong HIV-1-specific ADCC and were able to delay the spread of HIV-1 for about 6 days in cell cultures.


CONCLUSIONS
Certain epitopes of the p24-core protein of HIV-1 can be expressed on living, HIV-infected T cells and are recognised by specific antibodies. Such antibodies can destroy infected cells by ADCC or delay the virus spread, and therefore, should be considered in immunisation strategies against HIV.
Grunow
R
R
Institute of Immunology and Allergology, Inselspital, Bern, CH-3010 Bern, Switzerland.
Franke
L
L
Hinkula
J
J
Wahren
B
B
Fenyö
E M
EM
Jondal
M
M
von Baehr
R
R