Phagocyte chemotaxis in the perinatal period

Raghunathan, Rukmani; Miller, Michael E.; Everett, Susan L.; Leake, Rosemary D.

doi:10.1007/bf00915228

Cited by 28 publications

(12 citation statements)

References 8 publications

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“…In the human neonate, factors suggested to be responsible for the defect include deficiency of membrane receptors, cytoskeletal abnormalities, and membrane rigidity (2)(3)(4)(5)17). We have previously shown that chemotaxis of neutrophils obtained from human cord blood is comparable to adult values and "increased" in comparison to chemotaxis of neutrophils from same infant 48-72 h after birth (18). Similarly, the present study has documented "normal" values in 120 day gestational age "stressed" (delivered 20 min after the first) lambs whereas their unstressed twins had significantly decreased chemotaxis.…”

Section: Neutrophil Chemotaxis Withsupporting

confidence: 80%

Ontogeny of Neutrophil Chemotaxis in Fetal Lambs

et al. 1986

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ABSTRAfl. Ontogeny of neutrophil chemotactic response using endotoxin activated adult sheep plasma as a source of complement derived chemotactic factor was examined in fetal lambs of gestational age 120-150 days. (Gestational period in sheep is approximately 150 days.) Neutrophils from fetal lambs of gestational age 120-130 days failed to respond to this chemotactic factor whereas neutrophils from fetal lambs above 131 days of gestational age responded at levels comparable to adult values. Examination of neutrophil chemotaxis in older fetuses using a different chemotactic factor derived from mitogen stimulated adult mononuclear cells revealed a selective failure of fetal neutrophils to respond to lymphocyte-derived chemotactic factor in the presence of a normal response to complement derived chemotactic factor. Among prematurely delivered twin fetuses alterations in comparison with the first twin or age-matched controls in peripheral neutrophi1 count (increase) and in chemotaxis (increase or decrease) were noted in second of twins delivered r 20 min after the first lamb, suggesting an extreme sensitivity of neutrophil functions to a variety of influences, similar to that seen in humans. Directed migration or chemotaxis of phagocytes induced by various chemotactic agents is an essential component of inflammatory response. Defects in chemotaxis are associated, as a clinical consequence, with an increased susceptibility to infections. Defects in phagocyte chemotaxis may be due to membrane defects, reduced number of receptors for the chemotactic agent, or to cytoskeletal abnormalities. The chemotactic defect of human neonatal phagocyte originally described by Miller (1) may be due to deficiencies in any or all these components (2-5). Ontogeny of some phagocytic functions, but not chemotaxis, has been evaluated in fetal and neonatal animal models (6, 7). The ovine fetus has been shown by us and other investigators to be an appropriate animal model to study the ontogeny of various biological phenomena (8,9). In this report, we describe the developmental sequence of neutrophil chemotaxis in fetal lambs, utilizing EAP as a source of complement-derived chemotactic factor. Results from simultaneous evaluation of neutrophil chemotactic responses to EAP and another chemotactic factor derived from mitogen-stimulated adult ovine mononuclear leukocyte (N-LDCF) in a limited number of fetuses are presented. In addition, neutrophil counts and chemotaxis in normal fetal lambs and their twins have been compared to document alterations that may be due to "stress" of delayed delivery. MATERIALS AND METHODSSample collection. Normal adult sheep were used as controls.Heparinized (10 U/ml) blood was collected from the external jugular vein. Lambs of gestational age 120-1 50 days and postnatal age 1-6 days were compared with adults. The gestational age was determined by time-dated breeding. The fetal lambs were normal and were being delivered prematurely for other studies. The fetuses were exposed by hysterotomy under maternal spinal anes...

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Section: Neutrophil Chemotaxis Withsupporting

confidence: 80%

Ontogeny of Neutrophil Chemotaxis in Fetal Lambs

et al. 1986

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“…A mildly to moderately decreased chemotaxis of neonatal monocytes in response to zymosan-activated serum has been demonstrated by a number of investigators [2,10,13,26]. However, normal to increased chemotactic response was observed when neonatal monocytes were exposed to either endotoxin-activated serum or chemotactic factor derived from adult lymphocytes [11,19,21]. Differences probably can be explained by variations in test procedures.…”

Section: Discussionmentioning

confidence: 99%

Phagocytic activities in neonatal monocytes

et al. 1986

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Monocytes play an essential role in cellular host defense as circulating phagocytes, as well as precursors of macrophages. We investigated the principal phagocytic activities in monocytes from cord blood of term infants by analysing adherence, random migration, chemotaxis, bactericidal activity, phagocytosis-associated chemiluminescence, production of superoxide anion (O-2) and generation of hydrogen peroxide (H2O2). All phagocytic functions of monocytes from neonates were shown quantitatively to be comparable to those of cells from healthy adult volunteers. The increased susceptibility of the human neonate to serious systemic infections cannot be related to an abnormality in monocyte function.

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“…Neutrophils in the perinatal period migrate more slowly (2) and granulopoiesis is decreased (3) compared with adults. As a consequence of this relative immunodeficiency, and defects in other aspects of innate and acquired immunity, the preterm and newborn infant has a higher incidence of bacterial infections and a more frequent occurrence of neutropenia in response to sepsis than older children or adults (4,5).…”

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confidence: 99%