Studies in a Murine Model Confirm the Safety of Griffithsin and Advocate Its Further Development as a Microbicide Targeting HIV-1 and Other Enveloped Viruses

Kouokam, Joseph Calvin; Lasnik, Amanda B.; Palmer, Kenneth E.

In the first experiment, groups of four animals were injected with either 10 mg/kg dose of GRFT in 100 µL PBS or the vehicle only at Day 1. Animal survival, behavior, and fitness were recorded after one and two weeks, and animals were euthanized at Day 15. In parallel, a higher single dose of 50 mg/kg GRFT was administered to 30 mice divided into three subgroups of 10 evaluated at one, seven, and 14 days post-treatment, respectively. As controls, three groups of five animals were treated with the vehicle PBS. Next, we studied the effects of GRFT after chronic administration. Here, two groups of 15 mice each were treated with 10 mg/kg GRFT or PBS on a daily basis for 14 days. Animals were sacrificed at Day 14 (nine mice per treatment group), Days 16 and 21 (three per treatment group at each time point, respectively). In all experiments, blood was collected immediately after euthanasia, and blood samples were submitted to complete blood count (CBC). In addition, plasma samples were evaluated for a panel of markers of organ toxicity, using blood chemistry techniques. After euthanasia, spleens, lungs, kidneys, livers, and hearts were extracted and weighed. In the case of the chronic treatment, kidney, liver, and spleen tissues were stained for histopathology studies. In addition, spleen cells were isolated and assessed for activation. In the last experiment, mice were injected with 10 daily doses of 2 mg/kg GRFT in 100 µL PBS, or vehicle only. Toxicity was assessed by measuring body and spleen weights, as well as splenocyte activation.