The experimental system that we employ is, by necessity, not fully reflective of a natural infection because of (i) the high dose of spirochetes that we inject directly into the mouse required to image them; and (ii) the Cd1d−/− mice that lack iNKT cells, which would otherwise disrupt dissemination and phagocytize extravasated spirochetes in the knee joint (46, 48). Here, CD1D is linked to infection.