CCR5 and infection: CCL3 and CCL4 are produced by dendritic cells [52], neutrophils [53], lymphocytes [54], and non-hematopoietic cells, such as endothelial and epithelial cells [55] in the peripheral tissue in situations of inflammation or infection, and orchestrate the immune responses by promoting the recruitment of CCR5-expressing leukocytes and also by contributing to their effector functions [13,53,56].