The role of CCL22 (MDC) for the recruitment of eosinophils during allergic pleurisy in mice

Abstract

Eosinophils are important inflammatory cells in allergic diseases. In the present study, we have investigated the effects of CCL22 on the recruitment of eosinophils in vivo and in vitro. CCL22 induced a dose- and time-dependent recruitment of eosinophils into the pleural cavity of mice, and this was dependent on the release of platelet-activating factor (PAF) and subsequent generation of CCL11. However, in an allergic pleurisy model, an anti-CCL22 polyclonal antibody given during sensitization or before challenge had no significant effect on eosinophil recruitment. CCL22 did not induce eosinophil chemotaxis in vitro but was able to induce eosinophil degranulation in vitro and in vivo. In conclusion, we show that although exogenously added CCL22 may induce eosinophil migration in vivo via release of PAF and CCL11 (eotaxin), endogenous production of CCL22 does not drive eosinophil migration during allergic inflammation. However, CCL22 may be an important activator of eosinophils once these cells have migrated into tissue.

A simple preparation method for mouse eosinophils and their responses to anti-allergic drugs

“…On the other hand, RANTES failed to elicit eosinophil migration. These results indicate that mouse eosinophils prepared by this method are functionally comparable to previously reported mouse eosinophils in terms of migration activity [25], and that at least CCR3 and PAF receptors expressed on these eosinophils were functional.…”

“…As shown in Figure 1B, almost all of the cells purified mouse eosinophils expressed CCR3, which has been used as eosinophil markers in peripheral blood cells from IL-5 TG mice [4]. The confirmation of eosinophil functions indicated that these cells were comparable to Schistosoma mansoni-infected mice derived [25] or human [1] eosinophils, in terms of eotaxin-induced chemotaxis. In addition, RANTES, which can bind to CCR1, CCR3 and CCR5 [32], had no significant effect on the migration of mouse eosinophils in vitro (Fig.…”

“…teristics of eosinophils. The cells from parasite-infected mice are also used in in vitro study, since eosinophils had been considered as the cells terminally differentiated and involved in host protection against parasites [19,25,31]. Many lines of recent findings, however, have changed this hypothesis to one that eosinophils are pleiotropic multifunctional leukocytes involved in the initiation and propagation of diverse allergic inflammatory responses [1].…”

Role of CCR4 Ligands, CCL17 and CCL22, During Schistosoma mansoni Egg-Induced Pulmonary Granuloma Formation in Mice

“…Although it is not know whether either chemokine directly activates pulmonary fibroblasts to generate collagen, both chemokines have been shown to regulate the movement of eosinophils into the lung. 18,19 Human 70 and mouse 71 eosinophils express CCR4 particularly during an allergic inflammatory response, and these cells have been implicated in experimental and clinical fibrotic responses in the lung. 72 In the present study, we observed that the immunoneutralization of either CCL17 or CCL22 significantly reduced the eosinophilia associated with the egg granuloma.…”

Cellular Mechanisms of CCL22-Mediated Attenuation of Autoimmune Diabetes

“…Notably, it has been reported that CCR4 and its ligands are able to modulate innate immune responses (17,18). A potential role for CCL22 in Treg function has been suggested by the observation that in breast tumors producing CCL22, infiltrating Tregs are characterized by higher activation status and proliferation rate (5).…”