IFN priming is necessary but not sufficient to turn on a migratory dendritic cell program in lupus monocytes.
J Immunol 2014 Jun 15; 192(12):5586-98.
Blood monocytes from children with systemic lupus erythematosus (SLE) behave similar to dendritic cells (DCs), and SLE serum induces healthy monocytes to differentiate into DCs in a type I IFN-dependent manner. In this study, we found that these monocytes display significant transcriptional changes, including a prominent IFN signature, compared with healthy controls. Few of those changes, however, explain DC function. Exposure to allogeneic T cells in vitro reprograms SLE monocytes to acquire DC phenotype and function, and this correlates with both IFN-inducible (IP10) and proinflammatory cytokine (IL-1β and IL6) expression. Furthermore, we found that both IFN and SLE serum induce the upregulation of CCR7 transcription in these cells. CCR7 protein expression, however, requires a second signal provided by TLR agonists such as LPS. Thus, SLE serum "primes" a subset of monocytes to readily (<24 >h) respond to TLR agonists and acquire migratory DC properties. Our findings might explain how microbial infections exacerbate lupus. J Immunol 2014 Jun 15; 192(12):5586-98.
Rodriguez-Pla, Alicia; Patel, Pinakeen; Maecker, Holden T; Rossello-Urgell, Jose; Baldwin, Nicole; Bennett, Lynda; Cantrell, Victoria; Baisch, Jeanine; Punaro, Marilynn; Gotte, Alisa; Nassi, Lorien; Wright, Tracey; Palucka, Anna Karolina; Banchereau, Jacques; and Pascual, Virginia, "IFN priming is necessary but not sufficient to turn on a migratory dendritic cell program in lupus monocytes." (2014). Faculty Research 2014. 105.