Expression of HCC-4 mRNA is increased in the presence of IL-10. (A) Two cDNA libraries were made from pools of elutriated human monocytes stimulated for 1, 2, 6, 12, and 24 hours with LPS (5 μg/mL) and IFN-γ (200 U/mL) in the presence of IL-10 (200 U/mL) or the neutralizing anti–IL-10 MoAb 19F1 (α-IL-10; 10 μg/mL). The cDNAs were treated with restriction enzymes to release their inserts and analyzed by Southern blotting with either a ³²P-labeled cDNAs for HCC-4 or MIP-3β, as indicated. For reference, the prominent MIP-3β band is approximately 800 bp in length. (B) Total RNA was obtained from elutriated human monocytes activated as described above for 1 or 12 hours. Ten micrograms of total RNA (per lane) was analyzed by Northern blotting with a ³²P-labeled HCC-4 probe. The sizes of the two HCC-4 messages found are indicated with arrows. The equivalence of loading was assessed by ethidium bromide staining of the RNA.