Lymphokine-augmented activation of avian heterophils

Abstract

Heterophils are important mediators of innate resistance in poultry, especially in young birds that have not yet developed an acquired immune response. Invasion of the intestinal mucosa by Salmonella spp. initiates the recruitment of large numbers of heterophils to the lamina propria. Thus, the heterophilic response can control, but not eliminate, bacterial numbers in the bird until development of acquired immunity. Unfortunately, chicks and turkey poults are highly susceptible to Salmonella infections during the first 4 d posthatch due to the functional immaturity of both the innate and acquired immune systems. We have previously shown that the administration of Salmonella enteritidis (SE)-immune lymphokines (ILK) into either 18-d-old developing embryos or day-of-hatch chicks and poults conferred increased resistance to SE organ invasion. In this review, we present evidence that the protection induced by ILK is mediated by vigorous recruitment and activation of heterophils. These activated heterophils migrate rapidly to the site of bacterial invasion where they phagocytize and kill the SE. Specifically, in vitro studies demonstrate an enhancement of functional activities of the heterophils including chemotaxis, adherence, phagocytosis, and bacterial killing. In addition, during the activation process, membrane expression of adhesion molecules rapidly changes from L-selectins to beta2 integrins (CB11b/CD18) on the cells that become activated. These results further demonstrate the validity of preventive activation in poultry to induce the migration of large numbers of activated phagocytic cells to the site of infection by a pathogenic organism. Importantly, this immunopotentiation of the inflammatory response by ILK, as described here, induces the functional maturation of heterophils during the first 4 d posthatch.

Local immunity of the respiratory mucosal system in chickens and turkeys

“…Their functions include chemotaxis, adherence, phagocytosis and killing bacteria, with the activity level being age-dependent in many birds (Kogut et al 1998).…”

Effect of Lidocaine Hydrochloride on the Function of Bovine Peripheral Leukocytes

“…It has been reported that Lid reduces the MFI of CD11b by half in human leukocytes [13]. Lan et al [14] reported that exposure of Lid-treated cells to hypoxia-reoxygenation resulted in lower neutrophil CD18 expression compared with controls. These results indicate that reduction of CD18 expression by Lid reduces firm adhesion of granulocytes to the endothelium and thus reduces granulocyte extravasation.…”

“…L-selectin, which is also referred to as CD62L, is a surface molecule constitutively expressed and functional in all granulocytes. CD62L is involved in initial contact of the granulocytes with the endothelium and mediates leukocyte rolling in order to find the sites of infections [14]. Beta2 integrins, also referred to as CD11/CD18 adhesion molecules, mediate firm adhesion of granulocytes to the endothelium following the rolling process by L-selectin, and they then facilitate granulocyte extravasation [14].…”

“…CD62L is involved in initial contact of the granulocytes with the endothelium and mediates leukocyte rolling in order to find the sites of infections [14]. Beta2 integrins, also referred to as CD11/CD18 adhesion molecules, mediate firm adhesion of granulocytes to the endothelium following the rolling process by L-selectin, and they then facilitate granulocyte extravasation [14]. It has been reported that Lid reduces the MFI of CD11b by half in human leukocytes [13].…”

Metabolismo oxidativo de heterófilos de avestruzes jovens

“…Sob estímulo, expressam receptores de membrana responsáveis pela aderência e migração pelo endotélio vascular, dirigindo-se por quimiotaxia ao sítio de infecção. Após fagocitose, há a morte do agente infeccioso por meio de enzimas líticas e agentes oxidantes (RODRÍGUEZ et al, 1997;KOGUT et al, 1998;FARNELL et al, 2003).…”