Lack of developmental neurotoxicity of MN rgp120/HIV-1 administered subcutaneously to neonatal rats

The potential for neurotoxic effects was evaluated in rat offspring after e xposure in utero and/or during the neonatal period to a recombinant subunit vaccine of gp120 prepared from the MN strain of HIV-1 (MN rgp120/HIV-1). T hirty pregnant female rats were given MN rgp120/HIV-1 with alum adjuvant, a nd 30 rats were given vehicle, once every 3 days from Day 1 of presumed ges tation until parturition. One pup/sex/litter from treated and control group dams were given a daily subcutaneous injection, from Day 1 through Day 22 postpartum (PP) of vehicle, MN rgp120/HIV-1, MN rgp120/HIV-1 with alum, or MN rgp120/HIV-1 with QS-21 adjuvant. Neurobehavioral and physical developme nt were evaluated (preweaning reflex and development, sexual maturation, mo tor activity, acoustic startle, passive avoidance, functional observational battery, and water M-maze testing), and tissues were processed for anatomi cal examination (whole and regional brain weights, and neuropathology). Adm inistration of MN rgp120/HIV-1, with or without adjuvant, to pups did not c ause any persistent effect on any parameter evaluated. Neurohistological ex amination did not reveal any pathological effects related to treatment. Thu s, MN rgp120/HIV-1 alone or formulated as a vaccine does not cause neurotox icity or developmental toxicity in neonatal rats after exposure in utero an d/or during the neonatal period.