The influence of TNFα and IL-8 on secretory action of neutrophils isolated from heifers in the course of bovine respiratory disease

Abstract

The goal of this study was to give insight into the lesser known action of neutrophils in the course of bovine respiratory disease (BRD). Neutrophils are principally involved in resistance to infection but under certain conditions these cells participate in lung injury. TNFα and IL-8, primary cytokines which play an essential role in neutrophil activation during the inflammatory process, may lead not only to host defence reaction but also to destructive responses. Neutrophil constituents, such as elastase, myeloperoxidase (MPO), alkaline phosphatase (ALKP) and superoxide among others, contribute to tissue destruction. Also, 5-oxo-eicosatetraenoic acid (5-oxo-ETE), the potent activator of neutrophil chemotaxis and degranulation, can cause lung injury. This study revealed that neutrophils under the influence of TNFα exacerbated the release of elastase, MPO, ALKP and superoxide. IL-8, in turn, triggered those neutrophils which were isolated from heifers suffering from BRD, and released elastase, ALKP and 5-oxo-ETE, but not MPO or superoxide (O 2− ). The most pronounced degranulative response was observed in the acute form of BRD and a lesser response was seen in the chronic form. The secretory action of neutrophils varied not only depending on the form and phase of the disease but it also diminished successively during recovery.

Elastase, Myeloperoxidase, and Alkaline Phosphatase Release and Free Radical Generation in Neutrophils Isolated from Blood of Sows at Different Stages of Oestrous Cycle

“…Blood neutrophils were isolated according to the previously described method (19). After cell counting and differentiation (>85% of neutrophils on MayGrünwald-Giemsa-stained preparations), cell suspensions were adjusted to a final concentration of 2 x 10 6 cells/mL in Dulbecco's Modified Eagle's Medium (DMEM-Sigma).…”

“…MPO and ALKP releases were evaluated after 10 min incubation at room temperature with an equal volume of o-phenylendiamine (OPD-Sigma) or 4-nitrophenyl phosphate disodium salt hexahydrate (pNPP-Sigma), respectively. Absorbance was assessed on an ALAB-PLATE READER ELISA at 492 nm for elastase and MPO, and at 405 nm for ALKP (19,20).…”

The influence of porcine prophenin on neutrophils isolated from rabbit blood during implantation of calcium sulphate graft material into bone tissue

“…Absorbance was measured on ALAB-PLATE READER ELISA at 492 nm. All samples were assayed in duplicate (Wessely-Szponder, 2008).…”

“…This enzyme takes part in oxidative stress by formation of hypochlorous acid from the H 2 O 2 -MPO system (Faurschou and Borregaard, 2003). However, while local neutrophil migration to the site of tissue damage is important for wound healing and protection against invading organisms, systemic activation can lead to sequestration in organs and can cause tissue damage from released enzymes and free radicals (Lentz et al, 2007;Wessely-Szponder, 2008). Hence, diminution of the inflammatory response may provoke postoperative complications such as bacterial infections, whereas excessive inflammation can lead to tissue injury and multiple organ failure (Zhou et al, 2007).…”

Comparison of the effects of two anaesthetic combinations in rabbits on some neutrophil functions in vitro

“…It is known that initial resistance to bacterial infection is mediated by them (Davidson et al, 1995). Activated neutrophils can degranulate and release some enzymes such as elastase, myeloperoxidase (MPO), alkaline phosphatase (ALKP) and free radicals; moreover, they would be more resistant to apoptosis (Lentz et al, 2007, Wessely-Szponder, 2008. MPO is a specific enzyme of primary granules of neutrophils and is a marker of in vivo neutrophil activation (Hans et al, 1991).…”