Serpinb9 is a marker of antigen cross-presenting dendritic cells

Authors:

• Mangan, M.S.
• Vega-Ramos, J.
• Joeckel, L.T.
• Mitchell, A.J.
• Rizzitelli, A.
• Roediger, B.
• Kaiserman, D.
• Weninger, W.W.
• Villadangos, J.A.
• Bird, P.I.

Details:

Molecular Immunology, Volume 82, 2017-02-28

Article Link: Click here

Serpinb9 (Sb9, also called Spi6) is an intracellular inhibitor of granzyme B (grB) that protects cytotoxic lymphocytes from grB-mediated death. In addition, Sb9 is also expressed in accessory immune cells, including dendritic cells (DCs), although its role is debated. Recently, we have demonstrated that Sb9 plays a grB-independent role in cross-presentation of antigens by CD8+ DCs. Here, using a mouse line expressing green fluorescent protein knocked in under the control of the Sb9 promoter, we demonstrate that Sb9 expression is highest in those tissue-resident and migratory DC subsets capable of cross-presentation. Further, we show that CD8+ DCs can be divided into two subsets based on Sb9 expression, and that only the subset expressing higher levels of Sb9 is capable of cross-presentation. These findings add support for role for Sb9 cross-presentation, and indicate that high Sb9 expression is a novel marker of cross-presentation capable DCs.