title: Dendritic cells in hyperplastic thymuses from patients with myasthenia gravis.
abstract: To investigate the role of dendritic cells (DCs) in the hyperplastic myasthenia gravis (MG) thymus, we studied the frequency and distribution of three mature DC phenotypes (CD83(+)CD11c(+), CD86(+)CD11c(+), and HLA-DR(+)CD11c(+)) in samples from patients with MG whose symptoms dramatically improved following thymectomy and in non-MG control thymuses. In hyperplastic MG thymuses, mature DCs were much more numerous in nonmedullary areas, such as the subcapsular/outer cortex; around the germinal centers; and in extralobular connective tissue, particularly around blood vessels. Mature DCs strongly coexpressed CD44 and appeared to be components of a CD44-highly positive (CD44(high)) cell population migrating from the vascular system. Furthermore, in the hyperplastic MG thymus, the expression of secondary lymphoid-tissue chemokine (SLC) markedly increased especially around extralobular blood vessels, where the CD44(high) cell population accumulated. These findings suggest that DCs may migrate into the hyperplastic thymus from the vascular system via mechanisms that involve CD44 and SLC. DCs may present self-antigens, thereby promoting the priming and/or boosting of potentially autoreactive T cells against the acetylcholine receptor.
authors.affiliation: Department of Neurology, Iwate Medical University, Uchimaru 19-1, Morioka 020-8505, Japan.
authors.forename: Yuriko
authors.initials: Y
authors.lastname: Nagane
authors.forename: Kimiaki
authors.initials: K
authors.lastname: Utsugisawa
authors.forename: Daiji
authors.initials: D
authors.lastname: Obara
authors.forename: Munehisa
authors.initials: M
authors.lastname: Yamagata
authors.forename: Hideo
authors.initials: H
authors.lastname: Tohgi
mesh_terms: D000293:Adolescent; D000328:Adult; D002465:Cell Movement / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology / Q000473:pathology*; D005260:Female; D015870:Gene Expression / Q000276:immunology; D006801:Humans; D018960:Hyaluronan Receptors / Q000235:genetics; D008297:Male; D009157:Myasthenia Gravis / Q000276:immunology / Q000473:pathology*; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D013950:Thymus Gland / Q000276:immunology / Q000473:pathology*; D013952:Thymus Hyperplasia / Q000276:immunology / Q000473:pathology*
chemical_list: D018960:Hyaluronan Receptors