Response of porcine peripheral blood mononuclear cells to CpG-containing oligodeoxynucleotide

Exposure to bacterial DNA generates a "danger signal" that stimulates cellu lar elements of the mammalian immune system to proliferate and/or secrete c ytokines. Stimulation is critically dependent on hexameric motifs that cont ain an unmethylated CpG dinucleotide: these are commonly found in bacterial but not vertebrate DNA. Different motifs are optimally stimulatory in diff erent species. This work examines whether oligodeoxynucleotides (ODNs) cont aining CpG motifs stimulate peripheral blood mononuclear cells from pigs. R esults show that pigs respond to CpG ODN by proliferating and secreting IL- 6, IL-12 and TNF-alpha. By screening a large panel (>100) of ODNs, the pali ndromic hexamer 'ATCGAT' was identified as being optimally active in all an imals examined (N = 10). These findings are the first to establish the immu nostimulatory activity of CpG ODN in pigs, and suggest that the therapeutic uses envisioned for these ODNs (as vaccine adjuvants and immunoprotective agents) may be applicable to husbandry animals. (C) 2001 Elsevier Science B .V. All rights reserved.