We took advantage of the recently generated 4F7 mAb, which recognizes an epitope expressed on dendritic cells (DC) from different tissues, to freshly isolate and positively sort for these cells and to characterize their cytokine pattern and antigen-presenting capacity in comparison with epidermal Langerhans cells (LC). RT-PCR and Northern blot analyses demonstrated constitutive mRNA expression of MIP-1γ, MIP-1α, C10, and IL-1β in both 4F7+ DC and LC. Lipopolysaccharide (LPS) treatment resulted in the upregulation of mRNA expression of all four cytokines and in a newly detected signal for TNFα. Immunoblot analysis showed constitutive secretion of MIP-1γ, with LPS treatment resulting in the upregulation of IL-1β production and in newly detected TNFα secretion. 4F7+ DC were also shown to express mRNA for the common γ chain receptor of IL-2 and for the receptor of IL-4. Finally, we demonstrated freshly isolated 4F7+ DC to be equivalent to freshly isolated LC in their capacity to present alloantigen in the mixed leukocyte reaction (MLR) and to process and present purified protein derivative (PPD) to Th1 and Th2 clones, We conclude that 4F7 is a useful marker for positively sorting DC from dermis, spleen, and lymph nodes. Regardless of tissue source, 4F7+ DC exhibit uniform cytokine and antigen-presenting capacity profiles that mimic the properties of freshly isolated epidermal LC.
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