Differential gene expression of TLR7 overexpressing inflammatory hemophagocytes, Ly6Chi Monocytes, and Red Pulp Macrophages

We have defined a novel population of monocyte-derived hemophagocytes (inflammatory hemophagocytes (iHPC)) found in situations of inflammation, such as TLR7.1 mice that overexpress TLR7. These iHPC are similar yet distinct from red pulp macrophages (RPM) and differentiate in response to chronic TLR7 signals. In vivo, iHPC phagocytose red blood cells and platelets causing anemia and thrombocytopenia. We performed this study to further understand iHPC and their relationship to RPM and monocytes and determine what gene signatures make them unique. We sorted the following populations from spleens of 9-16 week old female WT B6 and TLR7.1 mice: iHPCs (TLR7.1 mice), Ly6Chi monocytes (WT B6 and TLR7.1 mice), and RPM (WT B6 and TLR7.1 mice). iHPC were identified as Live, CD45.2+, SiglecF-, Ly6G-, Ly6C-, CD31hi,VCAMlow, F4/80low,CD11b+ cells; monocytes were defined as Live, CD45.2+, SiglecF-, Ly6G-, Ly6C+, Ccr2+, CD11b+ cells; and RPM were defined as Live, CD45.2+, SiglecF-, Ly6G-, Ly6C-, CD31low,VCAMhi, F4/80+,CD11b-/int cells. We submitted lysates from 6 samples of each population (a total of 30 samples).