7th International AIDS Conference Florence, Italy — June 16-21, 1991

Int Conf AIDS 1991 Jun 16-21; 7:27 (abstract no. M.A.21)
Putkonen P, Thorstensson R, Albert J, Hild K, Biberfeld G, Norrby E; Dept. of Immunology, National Bact. Lab.

OBJECTIVE: To evaluate the efficacy of passive immunization against HIV-2 and SIVsm infection in cynomolgus monkeys (Macaca Fascicularis).

METHODS: Sera with high antibody titers were heat treated and injected intravenously (iv) into naive animals six hours before iv challenge with live homologous cell-free virus. In the first experiment four animals received a low dose (3 ml/kg) and three a high dose (9 ml/kg) of anti-HIV-2 serum (from a vaccinated monkey). Passively immunized animals together with 7 controls were challenged with 10 animal ID50 of HIV-2SBL-6669/H5. In the second experiment four animals received 9 ml/kg of anti-SIVsm serum (from a clinically healthy SIVsm infected monkey) and were challenged along with 6 controls with 1-10 ID50 of SIVsm. Infection was determined by virus isolation, by antibody response and by PCR analysis.

RESULTS: In the first experiment at a low dose of anti-HIV-2 antiserum one of four animals and at the higher dose two of three monkeys showed no signs of infection after the homologous HIV-2 challenge. All 7 control animals became infected with HIV-2. In the second experiment three of four monkeys pretreated with SIVsm antiserum were protected against a SIVsm challenge whereas all six controls became infected.

CONCLUSIONS: These results show that passively transferred antibodies can protect against a low dose lentivirus challenge in a non-human primate.

Copyright © 1991 - International AIDS Society (IAS). Reproduction of this abstract (other than one copy for personal reference) must be cleared through the IAS.