Molecular Cloning, Chromosomal Location, and Biological Activity of Porcine Interleukin-21

Abstract

ABSTRACT. A pig interleukin-21 (IL-21) cDNA was successfully cloned and sequenced from porcine peripheral blood lymphocytes (PBL) stimulated with 10 µg/ml concanavalin A (ConA), 10 µg/ml phytohemagglutinin P (PHA), 50 ng/ml phorbol 12-myristate 13-acetate (PMA), and 0.5 µg/ml anti-porcine CD3 antibody for 48 hr. The open reading frame of the porcine IL-21 cDNA is 459 base pairs in length and encodes 152 amino acids. The predicted amino acid sequence of the porcine IL-21 shows 86.2%, 77.7%, and 58.4% identi ty to the bovine, human, and murine IL-21, respectively. The porcine IL-21 gene was mapped to porcine chromosome 8 (8q22→q23) by means of fluorescence in situ hybridization and radiation hybrid mapping, where the porcine IL-2 gene had been mapped nearby. The recombinant porcine mature IL-21 expressed by E. coli induced dose-dependent proliferation and IFN-γ production from a human NK cell line, NK0. The porcine IL-21 identified in this study will be helpful for the enhancement of innate immune responses of pigs. KEY WORDS: cloning, innate immunity, interleukin-21, NK cell, porcine.J. Vet. Med. Sci. 66(3): 269-275, 2004 Interleukin-21 (IL-21) is a novel cytokine that regulates the proliferation of T and B cells, and involves the maturation and expansion of NK cells from bone marrow progenitor cells [20]. IL-21 is produced by activated T cells [20,21], and is a four-helix-bundle type I cytokine with structural similarity to IL-2, 21]. IL-21 receptor also has significant amino acid similarities with IL-2, , and shares the common γ chain for the subunit of the IL-21 receptor complex [2]. The common γ chain-containing receptor binded by its ligand such as IL-2 and IL-21 causes the activation of the Janus tyrosine kinase family 3 (JAK3) [6,17], and transduce its signal to the downstream molecules. Recent studies have indicated that IL-21 has various biological activities that affect T and NK cell functions [20,21] . Currently, IL-21 is thought to be a mediator cytokine, which promotes the transition from innate to adaptive immunity [9,21].One of the most interesting characteristics of IL-21 is its effect on NK cell maturation and expansion [20], because pigs have high NK cell populations in the peripheral blood [31], and many piglets suffer from diarrhea and respiratory diseases in their neonatal periods during which adaptive immunity is immature. We previously reported the cloning and expression of porcine , and the IFN-γ induction by IL-18 from neonatal piglets [13]. Recently, Strengell et al. reported that IL-21 also enhances IFN-γ production from human NK and T cells in synergy with . Taken, together, we would like to isolate porcine IL-21, a recent cytokine that promotes the transition from innate to adaptive immunity [9,21], in order to utilize this cytokine for the enhancement of neonatal immunity of pigs. We also reported the cloning, and the expression of bovine IL-21 using a baculovirus expression system [15].In the present study, cDNA encoding porcine IL-21 was cloned and characterized, and the chromos...

Quantitative trait loci for white blood cell numbers in swine

“…2004) on SSC1 and IL2 (the interleukin 2 gene, Ellegren et al. 1993), IL21 (the interleukin 21 gene, Muneta et al. 2004), IL8 (the interleukin 8 gene, Shimanuki et al.…”

“…The QTL maximum on SSC8 (day 14) maps to a region harbouring the genes for IL2 , IL15 and IL21 (Ellegren et al. 1993; Muneta et al. 2004).…”

Confirmation of QTL on porcine chromosomes 1 and 8 influencing leukocyte numbers, haematological parameters and leukocyte function

“…2002). Interestingly, the IL21 gene was recently cytogenetically mapped to this region (Muneta et al. 2004) and might also be involved in the observed effects as this cytokine is involved in lymphocyte maturation (Nutt et al.…”

The common gamma chain cytokine interleukin‐21 is expressed by activated lymphocytes from two macropod marsupials, Macropus eugenii and Onychogalea fraenata

“…Interleukin‐21 is characterized in a wide variety of vertebrate species including humans, mice (Parrish‐Novak et al ., , ), pigs (Muneta et al ., ), cattle (Muneta et al ., ), chickens (Rothwell et al ., ), pufferfish (Bird et al ., ) and rainbow trout (Wang et al ., ). In mammals such as humans and mice, the canonical IL‐21 gene is composed of five exons and both of these species also express an IL‐21 isoform, which retains intron four in the mature protein (Rahman et al ., ).…”