title: Heat-killed whole-cell products of the probiotic Pseudomonas aeruginosa VSG2 strain affect in vitro cytokine expression in head kidney macrophages of Labeo rohita.
abstract: Present study was undertaken to investigate the efficiency of heat-killed whole-cell products (HKWCPs) of probiotic Pseudomonas aeruginosa VSG2 strain in stimulating the cytokine responses in the head kidney (HK) macrophages of Labeo rohita. The HK macrophages were incubated with HKWCPs or lipopolysaccharide (LPS), and the responses of cytokine genes, namely interleukin-10 (IL-10), IL-1β, IL-p35, IL-12p40, tumour necrosis factor-α (TNF-α), nuclear factor kappa B (NF-κB), cyclooxygenase-2 (COX-2), interferon-alpha (IFN-α), and interferon-gamma (IFN-γ) were assessed by quantitative real-time PCR (qRT-PCR) at 2, 8, 16, 24, 48, 72 h post-stimulation (hps). Among proinflammatory cytokines, significantly higher expression of IL-1β and TNF-α was observed at 8-24 hps, and 2-16 hps with HKWCPs, respectively, as compared to controls. However, COX-2 and NF-κB displayed strong expression (P < 0.05) at 2-8 hps, and 8, 16 and 72 hps with HKWCPs, respectively. Antiviral cytokines IFN-α and IFN-γ displayed strong expression (P < 0.05) at 8-24 hps, and 2, 24 and 48 hps with HKWCPs, respectively. Expressions of cell-mediated immune factor genes (IL-12p35 and IL-12p40) were also significantly upregulated at various time points, except IL-12p40 at 72 hps, in HK macrophages stimulated with HKWCPs. Expression of the anti-inflammatory cytokine IL-10 was upregulated (P < 0.05) at 2-24 hps HKWCPs, compared to controls. Enhanced cellular (phagocytic activity and superoxide anion production) and humoral (lysozyme) immune parameters of treated HK macrophages confirmed the induction of inflammatory response. Thus, our results indicated that HKWCPs of probiotic P. aeruginosa VSG2 had greater potential for stimulating the in vitro expression of cytokines in fish and that these HKWCPs may be used as vaccine adjuvants in aquaculture.
authors.affiliation: Laboratory of Aquatic Biomedicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul 151742, South Korea; Dept. of Biotechnology, Periyar Maniammai University, Thanjavur 613403, Tamil Nadu, India. Electronic address: giribiotek@gmail.com.
authors.forename: Sib Sankar
authors.initials: SS
authors.lastname: Giri
authors.affiliation: School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India. Electronic address: shibsankar.iicb@gmail.com.
authors.forename: Shib Sankar
authors.initials: SS
authors.lastname: Sen
authors.affiliation: Laboratory of Aquatic Biomedicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul 151742, South Korea. Electronic address: advancewoo@snu.ac.kr.
authors.forename: Jin Woo
authors.initials: JW
authors.lastname: Jun
authors.affiliation: Laboratory of Aquatic Biomedicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul 151742, South Korea. Electronic address: parksec@snu.ac.kr.
authors.forename: Se Chang
authors.initials: SC
authors.lastname: Park
authors.affiliation: Dept. of Biotechnology, Periyar Maniammai University, Thanjavur 613403, Tamil Nadu, India; Dept. of Zoology, Kundavai Nachiyar Government Arts College for Women (Autonomous), Thanjavur 613007, Tamil Nadu, India. Electronic address: drvsukumar@gmail.com.
authors.forename: V
authors.initials: V
authors.lastname: Sukumaran
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D003530:Cyprinidae / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism; D016207:Cytokines / Q000235:genetics* / Q000378:metabolism; D060226:Head Kidney / Q000276:immunology; D008264:Macrophages / Q000276:immunology; D019936:Probiotics / Q000008:administration & dosage / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000737:chemistry*; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary
chemical_list: D016207:Cytokines
keywords: Cytokine response; HKWCPs; LPS; Labeo rohita; Macrophage; Pseudomonas aeruginosa VSG2