Observations on the functional integrity of neutrophil leucocytes infected with tick-borne fever

Foster, W.N.M.; Cameron, A. E.

doi:10.1016/0021-9975(70)90081-2

Cited by 27 publications

(11 citation statements)

References 6 publications

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“…Similarly, defects in leukocyte adhesion, as demonstrated here, also contribute to an immunosuppressive state (32). Defects in phagocytosis, microbicidal activity, and motility have also been described for A. phagocytophilum-infected cells (19,41). The possibility that these abnormalities support clinical manifestations is suggested by opportunistic infections in humans and horses and more dramatically by the occurrence of frequently fatal infections such as pyemia (disseminated staphylococcal infection) in pasture-raised sheep and goats after tick-borne fever (16,39,41).…”

Section: Discussionsupporting

confidence: 73%

Diminished Adhesion ofAnaplasma phagocytophilum-Infected Neutrophils to Endothelial Cells Is Associated with Reduced Expression of Leukocyte Surface Selectin

et al. 2003

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Anaplasma phagocytophilum propagates within neutrophils and causes a disease marked by inflammatory tissue injury or complicated by opportunistic infections. We hypothesized that infection with A. phagocytophilum modifies the binding of neutrophils to endothelial cells and the expression of neutrophil adhesion molecules and studied these changes in vitro. Infected dimethyl sulfoxide-differentiated HL-60 cells and neutrophils showed reduced binding to cultured brain and systemic endothelial cells and lost expression of P-selectin glycoprotein ligand 1 (PSGL-1, CD162) and L-selectin (CD62L) (to 33 and 5% of control values, respectively), at a time when the levels of ␤ 2 integrin and immunoglobulin superfamily adhesion molecules and activation markers Mac-1 and intercellular adhesion molecule 1 increased (5 to 10 times that of the control). The loss of CD162 and CD62L expression was inhibited by EDTA, which suggests that neutrophil activation and sheddase cleavage occurred. The loss of selectin expression and the retained viability of the neutrophils persisted for at least 18 h with A. phagocytophilum infection, whereas Escherichia coli and Staphylococcus aureus rapidly killed neutrophils. The adhesion defect might increase the numbers of infected cells and their persistence in the blood prior to tick bites. However, decreased CD162 expression and poor endothelial cell binding may partly explain impaired host defenses, while simultaneous neutrophil activation may aggravate inflammation. These observations may help us to understand the modified biological responses, host inflammation, and immune response that occur with A. phagocytophilum infections.

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Section: Discussionsupporting

confidence: 73%

Diminished Adhesion ofAnaplasma phagocytophilum-Infected Neutrophils to Endothelial Cells Is Associated with Reduced Expression of Leukocyte Surface Selectin

et al. 2003

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“…Earlier investigations have shown that lambs are susceptible to secondary infections, especially in the bacteraemic and neutropenic periods of TBF [14,27-29]. In the present study, only the rate of bacteraemia is different between the two breeds.…”

Section: Discussioncontrasting

confidence: 49%

A comparative study of clinical manifestations, haematological and serological responses after experimental infection with Anaplasma phagocytophilum in two Norwegian sheep breeds

et al. 2011

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BackgroundIt has been questioned if the old native Norwegian sheep breed, Old Norse Sheep (also called Norwegian Feral Sheep), normally distributed on coastal areas where ticks are abundant, is more protected against tick-borne infections than other Norwegian breeds due to a continuously high selection pressure on pasture. The aim of the present study was to test this hypothesis in an experimental infection study.MethodsFive-months-old lambs of two Norwegian sheep breeds, Norwegian White (NW) sheep and Old Norse (ON) sheep, were experimentally infected with a 16S rRNA genetic variant of Anaplasma phagocytophilum (similar to GenBank accession number M73220). The experiment was repeated for two subsequent years, 2008 and 2009, with the use of 16 lambs of each breed annually. Ten lambs of each breed were inoculated intravenously each year with 0.4 ml A. phagocytophilum-infected blood containing approximately 0.5 × 106 infected neutrophils/ml. Six lambs of each breed were used as uninfected controls. Half of the primary inoculated lambs in each breed were re-challenged with the same infectious dose at nine (2008) and twelve (2009) weeks after the first challenge. The clinical, haematological and serological responses to A. phagocytophilum infection were compared in the two sheep breeds.ResultsThe present study indicates a difference in fever response and infection rate between breeds of Norwegian sheep after experimental infection with A. phagocytophilum.ConclusionAlthough clinical response seems to be less in ON-lambs compared to NW-lambs, further studies including more animals are needed to evaluate if the ON-breed is more protected against tick-borne infections than other Norwegian breeds.

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“…e Measurements are based on plots of daily temperature on 5-mm 2 grids (see text for details). lambs in the bacteremic and neutropenic periods of TBF are more susceptible to secondary infections (2,5,7,19). The present study may indicate, therefore, that general resistance to other infectious agents is less affected in lambs infected with A. phagocytophilum variant 2.…”

Section: Discussionmentioning

confidence: 56%

Differences in Clinical Manifestations and Hematological and Serological Responses after Experimental Infection with Genetic Variants ofAnaplasma phagocytophilumin Sheep

Stuen

Bergström

Petrovec

et al. 2003

Clin Vaccine Immunol

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Five-month-old lambs were experimentally infected with two 16S rRNA genetic variants of Anaplasma phagocytophilum, variants 1 (GenBank accession no. M73220) and 2 (GenBank accession no. AF336220). Additional sequencing of the groESL heat shock operon gene indicated that these variants differ in three nucleotides at positions 782, 824, and 890. The variants were obtained by blood sampling of A. phagocytophiluminfected lambs from one sheep flock in Norway and were stored at ؊70°C with 10% dimethyl sulfoxide as a cryoprotectant before being inoculated intravenously into susceptible lambs. The infectious blood contained, per ml, approximately 0.5 ؋ 10 6 neutrophils infected with either of the variants. Six weeks after the primary inoculation, the lambs were challenged with the same infectious dose of the heterologous variant. The results of the study indicate a marked difference in clinical manifestation, neutropenia, antibody response, and cross-protection after experimental infection with the two variants of A. phagocytophilum.

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Observations on the functional integrity of neutrophil leucocytes infected with tick-borne fever

Cited by 27 publications

References 6 publications

Diminished Adhesion ofAnaplasma phagocytophilum-Infected Neutrophils to Endothelial Cells Is Associated with Reduced Expression of Leukocyte Surface Selectin

Diminished Adhesion ofAnaplasma phagocytophilum-Infected Neutrophils to Endothelial Cells Is Associated with Reduced Expression of Leukocyte Surface Selectin

A comparative study of clinical manifestations, haematological and serological responses after experimental infection with Anaplasma phagocytophilum in two Norwegian sheep breeds

Differences in Clinical Manifestations and Hematological and Serological Responses after Experimental Infection with Genetic Variants ofAnaplasma phagocytophilumin Sheep

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