Fractalkine expression and CD16 monocyte accumulation in glomerular lesions: association with their severity and diversity in lupus models

Fractalkine (Fkn) is expressed on injured endothelial cells and is a membrane-bound chemokine that attracts cells expressing its receptor, CX3CR1, including CD16+ monocytes (CD16+ Mos). To clarify the role played by Fkn in the development of glomerular lesions in lupus nephritis, we examined Fkn expression and CD16+ Mo accumulation induced in experimental C.B-17/Inc-scid/scid (SCID) lupus model mice by injection of IgG3-producing hybridoma clones obtained from MRL/lpr mice. Glomerular Fkn expression and accumulation of CD16+ Mos were semiquantitatively evaluated using laser capture microdissection and real-time PCR. Injection of the 2B11.3 and 7B6.8 clones induced formation of glomerular proliferative and wire-loop lesions, respectively. Immunohistological analysis of the localization of Fkn and CD16+ Mos revealed that Fkn expression and CD16+ Mo accumulation were markedly elevated in glomerular lesions induced by 2B11.3, whereas no elevation was detected in those induced by 7B6.8. In addition, to examine...