Accessory cell function of human eosinophils. HLA-DR-dependent, MHC-restricted antigen-presentation and IL-1 alpha expression.
Although peripheral blood eosinophils express little of the class II MHC protein, HLA-DR, eosinophils could be induced to express HLA-DR by exposures to cytokines, including granulocyte-macrophage-CSF, IL-4, and IFN-gamma, with granulocyte-macrophage-CSF eliciting the greatest level of HLA-DR expression as assessed by flow cytometry. The capacity of HLA-DR+ eosinophils to function as APC was evaluated with blood eosinophils isolated free of mononuclear cells, cultured with granulocyte-macrophage-CSF to induce HLA-DR expression and then exposed to the Ag tetanus toxoid. HLA-DR+ eosinophils fixed with paraformaldehyde after Ag exposure stimulated T cell proliferation, whereas HLA-DR+ eosinophils fixed with paraformaldehyde before Ag exposure failed to stimulate lymphocyte proliferation. The lymphocyte proliferative responses elicited by Ag-pulsed HLA-DR+ eosinophils were inhibited by anti-HLA-DR mAb and were restricted to HLA-DR compatible lymphocytes. Moreover, eosinophils from a hypereosinophilic donor, both before and more prominently after stimulation with PMA, contained transcripts for IL-1-alpha mRNA detectable by Northern blot hybridization and in situ hybridization and expressed IL-1-alpha protein detectable by immunohistochemistry. These findings indicate that human eosinophils can process Ag, express the costimulatory cytokine IL-1-alpha, and after cytokine-elicited induction of HLA-DR expression can function as HLA-DR-dependent, MHC-restricted APC in stimulating T lymphocyte responses.
Weller
P F
PF
Department of Medicine, Beth Israel Hospital, Boston, MA 02215.
Rand
T H
TH
Barrett
T
T
Elovic
A
A
Wong
D T
DT
Finberg
R W
RW
D000938:Antigen-Presenting Cells / Q000502:physiology*; D002478:Cells, Cultured; D016207:Cytokines / Q000494:pharmacology; D004804:Eosinophils / Q000276:immunology* / Q000378:metabolism / Q000502:physiology; D006684:HLA-DR Antigens / Q000032:analysis / Q000502:physiology*; D006801:Humans; D007375:Interleukin-1 / Q000096:biosynthesis* / Q000235:genetics
D016207:Cytokines; D006684:HLA-DR Antigens; D007375:Interleukin-1