Figure 4.

Dynamic of monocyte and monocyte derived cells during an ongoing adaptive immune response against L.a. infection: recruitment, activation and cell clusters. Infected monocytes (A) and CXCR3⁺ Th1 cells (B) produce CXCL9 and CXCL10 facilitating continuous recruitment of permissive immature inflammatory monocytes (C) that provides a niche for ongoing infection (D) and possibly favors the formation of monocyte-Th1 cell clusters. After infection, mon-Macs mediate some parasite killing when activated by IFN-γ (E); but when activated simultaneously by IFN-γ and Th2 cytokines (F) or by Th2 cytokines alone (G) support parasite replication. Infected monocytes can also be suppressed by IL-10, while receiving signals from IFN-γ and/or Th2 cytokines, which also favors parasite replication (H). Mature mon-DCs are more efficient at restricting parasite growth versus mon-Macs but this developmental program takes 7-14 days (I). Embryonic derived resident macrophages due to CCL24 production, cluster with eosinophils, which are an important source of IL-4 and IL-10 (J). Created with BioRender.com.