The in vivo interaction of Streptococcal mAb10F5 in Lewis rat brains : an honors thesis (HONRS 499)

Abstract

Group A streptococcal infection is being implicated in the formation of movement disorders such as PANDAS, Tourette syndrome, Sydenham's chorea, and general tics. It is suggested that antibodies produced against the conservative region of streptococcal M proteins are cross-reacting with neuronal tissue in an autoimmune response. One area of proposed cross-reactivity within the brain is the basal ganglia, the center for movement regulation. Antibodies against this region are called anti-basal ganglia antibodies. Monoclonal mouse antibody 10F5 (mAb10F5) is a streptococcal M6 antibody. Previous studies in our laboratory, using in vitro techniques, demonstrated that mAb10F5 bound in the basal ganglia of Lewis rats and has antiphospholipid properties. The current study sought to examine the interaction of mAb10F5 in Lewis rat brains in vivo. Rats were injected with either mAb10F5 or a positive control, myosin (type II) antibody, and euthanized after 24, 48, or 72 hours. Slices from the rostral and midrostral sections of these brains along with those of uninjected controls were analyzed using immunofluorescence and fluorescent microscopy. The caudate and putamen (CPu), a part of the basal ganglia, was significantly positive compared to controls at 24, 48, and 72 hours in the mAb10F5 treated group and at 24 and 48 hours in the myosin (type II) antibody treated group. It was discerned that in the mAb10F5 group the antibody crossed the blood-brain-barrier at 24 hours and remained in the CPu through 72 hours. The myosin (type II) antibody did not cross the blood-brain-barrier until 48 hours, and was no longer significantly in the CPu after 72 hours. These findings suggest that mAb10F5 is an anti-basal ganglia antibody and may be involved in movement disorders.