We discuss here important pro-inflammatory molecules and leucocyte populations that were identified as key players in the murine model of DENV-2 infection using the mouse-adapted strain P23085. The inflammatory response triggered by this model of DENV infection frequently leads to tissue damage and death. However, it is possible in this model to assess and distinguish mechanisms necessary for the host response
to deal with infection from those that cause unwanted, misplaced and uncontrolled inflammation and drive disease. selleckchem By understanding where/how host–pathogen interactions lead to disease, we may be able to suggest novel strategies to restrain severe systemic and local inflammatory responses. Chemokines are members of a structurally related family of cytokines involved in leucocyte Epacadostat traffic during infection and inflammation. They are classified according to the relative position of conserved N-terminal cysteine residues, in which CC
chemokines represent the most abundant family and have the first two cysteines placed adjacently. Chemokine receptors are expressed on the surface of leucocytes and are G protein-coupled receptors containing seven transmembrane domains. Experimental and epidemiological evidence suggests an important role for chemokines, especially those from the CC family, and their receptors in infectious diseases such as HIV and herpes simplex virus 1.[74, 75] The expression of CC chemokines dominates over the expression of CXC chemokines during
viral infections, although this observation does not represent a general rule. Among the CC chemokines, CCL3/MIP-1α and CCL5/regulated upon activation, normal T cell-expressed and secreted (RANTES) are widely associated with viral infections [74, 76] During intranasal influenza virus infection in mice, CCL2/monocyte chemotactic protein-1 (MCP-1) is detected in the lungs at various time-points post-infection, whereas other chemokines, including CCL3 and CCL5, are not expressed. On the other hand, respiratory syncytial virus-infected mice display high levels of expression of numerous about chemokines in the lungs, including CCL3 and CCL5. Among flaviviruses, CC chemokine receptors play an important role in leucocyte recruitment to the central nervous system. Besides a deleterious pro-inflammatory role that CC chemokines could play in central nervous system, a well-studied example involves acute infection by West Nile virus in mice, in which the lack of CCR2 and CCR5 leads to decreased leucocyte recruitment, increased viral load in the central nervous system and enhanced mortality. West Nile virus infection induces high and continuous levels of CCL2 and CCL5, which are required for the local accumulation of NK cells, macrophages and T lymphocytes to control infection.