Figure 2: Our published findings established that in vivo Vpr expression mimics HIV-DSP features in transgenic immunosuppressed vpr/RAG1-/- mice [22,23]. A) Von Frey filament testing confirmed vpr/RAG1-/- mice have a lower pain threshold than their RAG1-/- age-matched control mice. B) Epidermal nerve fiber counts indicated the vpr/RAG1-/- mice have significantly less free nerve terminals than the RAG1-/- age-matched control mice.