Immunohistochemical assessment of fractalkine, inflammatory cells, and human herpesvirus 7 in human salivary glands.
Human fractalkine (CX3CL1), a delta-chemokine, is implicated in the mediation of multiple cell functions. In addition to serving as a chemotactic factor for mononuclear cell subtypes, membrane-bound fractalkine may promote viral infection by interacting with virions that encode putative fractalkine-binding proteins. Fractalkine expression in normal epithelial tissues studied to date is either constitutive or is upregulated with inflammation. In salivary glands, the expression of fractalkine is unknown. Moreover, salivary glands are a major site for the persistent and productive infection by human herpesvirus (HHV)-7, which encodes two putative fractalkine-binding gene products, U12 and U51. Surprisingly, the cellular distribution of HHV-7 in major salivary glands has not been explored. We therefore determined by immunohistochemistry the cellular localization of fractalkine in three different salivary glands: parotid, submandibular, and labial glands. Fractalkine expression was highly variable, ranging from high to undetectable levels. We further examined the association of fractalkine with inflammatory cell infiltration or HHV-7 infection of salivary epithelial cells. Inflammatory cells were always adjacent to epithelial cells expressing fractalkine, consistent with a function of fractalkine in inflammatory cell recruitment and/or retention in salivary glands. In contrast, HHV-7-infected epithelial cells did not always express fractalkine, suggesting that fractalkine may not be an absolute requirement for viral entry.
Latchney
Lisa R
LR
Center for Oral Biology, University of Rochester Medical Center, Rochester, New York, USA.
Fallon
Margaret A
MA
Culp
David J
DJ
Gelbard
Harris A
HA
Dewhurst
Stephen
S
D000328:Adult; D000368:Aged; D017252:CD3 Complex / Q000378:metabolism; D054428:Chemokine CX3CL1; D020523:Chemokines, CX3C / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism / Q000821:virology; D005260:Female; D016199:Herpesvirus 7, Human / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D007249:Inflammation / Q000276:immunology* / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism*; D008875:Middle Aged; D010306:Parotid Gland / Q000378:metabolism / Q000473:pathology / Q000821:virology; D012469:Salivary Glands / Q000378:metabolism* / Q000473:pathology / Q000821:virology; D013363:Submandibular Gland / Q000378:metabolism / Q000473:pathology / Q000821:virology
D017252:CD3 Complex; C515538:CX3CL1 protein, human; D054428:Chemokine CX3CL1; D020523:Chemokines, CX3C; D008565:Membrane Proteins