Cell Proliferation Induced by IL‑5 and Neutralization by Porcine IL‑5 Antibody. Recombinant Porcine IL‑5 (Catalog # 3137-PL) stimulates proliferation in the TF‑1 human erythroleukemic cell line in a dose-dependent manner (orange line). Proliferation elicited by Recombinant Porcine IL‑5 (25 ng/mL) is neutralized (green line) by increasing concentrations of Goat Anti-Porcine IL‑5 Antigen Affinity-purified Polyclonal Antibody (Catalog # AF3137). The ND50 is typically|
IL‑5 in Porcine PBMCs.|
IL‑5 was detected in immersion fixed porcine peripheral blood mononuclear cells treated with calcium ionomycin and PMA using Goat Anti-Porcine IL‑5 Antigen Affinity-purified Polyclonal Antibody (Catalog # AF3137) at 15 µg/mL for 3 hours at room temperature. Cells were stained using the NorthernLights™ 557-conjugated Anti-Goat IgG Secondary Antibody (red; Catalog # NL001) and counterstained with DAPI (blue). Specific staining was localized to cytoplasm. View our protocol for Fluorescent ICC Staining of Non-adherent Cells.
Interleukin-5 (IL-5) is a secreted disulfide-linked homodimeric glycoprotein that belongs to the alpha -helical group of cytokines that includes IL-3, IL-5 and GM-CSF (1‑3). IL-5 is primarily produced by CD4+ Th2 cells, but eosinophils and mast cells also produce IL-5. Porcine IL-5 is synthesized as a 134 amino acid (aa) precursor that contains a 19 aa signal sequence and a 115 aa mature segment (5). Four alpha -helices and two cysteines that form interchain disulfide bonds with a second, antiparallel IL-5 molecule are conserved among species (3 - 5). Monomeric IL-5 is a predicted 14 kDa protein but usage of N-linked glycosylation sites may increase its molecular weight (5). Mature porcine IL-5 shares 90%, 88%, 86%, 85%, 84%, 66%, 68%, 63%, 63% and 59% aa sequence identity with mature bovine, sheep, cat, equine, canine, human, guinea pig, cotton rat, murine and rat IL-5, respectively. Recombinant porcine IL-5 induced proliferation in the human TF-1 cell line (5). The receptor for human IL-5 consists of a 60 kDa ligand-binding subunit (IL-5 R alpha ) and a 120 kDa signal-transducing subunit ( beta c). It is suggested that dimeric IL-5 binding to IL-5 R alpha recruits beta c, which subsequently covalently links with IL-5 R alpha. Two receptor complexes then associate to form the physiologic IL-5 receptor (6, 7). IL-5 binds proteoglycans, potentially enhancing its activity (8). Following receptor binding, IL-5 promotes the maturation, activation and migration of eosinophils, as demonstrated during asthmatic eosinophilic lung inflammation (1‑3). It also mobilizes eosinophils and CD34+ progenitors from marrow. It also enhances Ig release from B cells and contributes to IL-4 production. Finally, it primes basophils for histamine and leukotriene release (1, 2, 9).