<i>Anaplasma phagocytophilum</i> Transmission Activates Immune Pathways While Repressing Wound Healing in the Skin

<i>Anaplasma phagocytophilum,</i> the causative agent of human granulocytic anaplasmosis (HGA), is an obligate intracellular bacterium transmitted by the bite of black-legged ticks, <i>Ixodes scapularis</i>. The main host cells in vertebrates are neutrophils. However, the fir...

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Main Authors: Jacob Underwood, Cristina Harvey, Elizabeth Lohstroh, Branden Pierce, Cross Chambers, Stephanie Guzman Valencia, Adela S. Oliva Chávez
Format: Article
Language:English
Published: MDPI AG 2022-11-01
Series:Life
Subjects:
Online Access:https://www.mdpi.com/2075-1729/12/12/1965
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author Jacob Underwood
Cristina Harvey
Elizabeth Lohstroh
Branden Pierce
Cross Chambers
Stephanie Guzman Valencia
Adela S. Oliva Chávez
author_facet Jacob Underwood
Cristina Harvey
Elizabeth Lohstroh
Branden Pierce
Cross Chambers
Stephanie Guzman Valencia
Adela S. Oliva Chávez
author_sort Jacob Underwood
collection DOAJ
description <i>Anaplasma phagocytophilum,</i> the causative agent of human granulocytic anaplasmosis (HGA), is an obligate intracellular bacterium transmitted by the bite of black-legged ticks, <i>Ixodes scapularis</i>. The main host cells in vertebrates are neutrophils. However, the first site of entry is in the skin during tick feeding. Given that the initial responses within skin are a crucial determinant of disease outcome in vector-borne diseases, we used a non-biased approach to characterize the transcriptional changes that take place at the bite during <i>I. scapularis</i> feeding and <i>A. phagocytophilum</i> transmission. Experimentally infected ticks were allowed to feed for 3 days on C57BL/6J mice to allow bacterial transmission and establishment. Skin biopsies were taken from the attachment site of uninfected ticks and <i>A. phagocytophilum</i>-infected ticks. Skin without ticks (intact skin) was used as baseline. RNA was isolated and sequenced using next-generation sequencing (NGS). The differentially expressed genes were used to identify over-represented pathways by gene ontology (GO) and pathway enrichment (PE). <i>Anaplasma phagocytophilum</i> transmission resulted in the activation of interferon signaling and neutrophil chemotaxis pathways in the skin. Interestingly, it also led to the downregulation of genes encoding extracellular matrix (ECM) components, and upregulation of metalloproteinases, suggesting that <i>A. phagocytophilum</i> delays wound healing responses and may increase vascular permeability at the bite site.
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spelling doaj.art-5fe4de01354d498a91b55cce0c55a7c22023-11-24T16:11:13ZengMDPI AGLife2075-17292022-11-011212196510.3390/life12121965<i>Anaplasma phagocytophilum</i> Transmission Activates Immune Pathways While Repressing Wound Healing in the SkinJacob Underwood0Cristina Harvey1Elizabeth Lohstroh2Branden Pierce3Cross Chambers4Stephanie Guzman Valencia5Adela S. Oliva Chávez6Department of Entomology, Texas A&M University, College Station, TX 77845, USADepartment of Entomology, Texas A&M University, College Station, TX 77845, USADepartment of Entomology, Texas A&M University, College Station, TX 77845, USADepartment of Entomology, Texas A&M University, College Station, TX 77845, USADepartment of Entomology, Texas A&M University, College Station, TX 77845, USADepartment of Entomology, Texas A&M University, College Station, TX 77845, USADepartment of Entomology, Texas A&M University, College Station, TX 77845, USA<i>Anaplasma phagocytophilum,</i> the causative agent of human granulocytic anaplasmosis (HGA), is an obligate intracellular bacterium transmitted by the bite of black-legged ticks, <i>Ixodes scapularis</i>. The main host cells in vertebrates are neutrophils. However, the first site of entry is in the skin during tick feeding. Given that the initial responses within skin are a crucial determinant of disease outcome in vector-borne diseases, we used a non-biased approach to characterize the transcriptional changes that take place at the bite during <i>I. scapularis</i> feeding and <i>A. phagocytophilum</i> transmission. Experimentally infected ticks were allowed to feed for 3 days on C57BL/6J mice to allow bacterial transmission and establishment. Skin biopsies were taken from the attachment site of uninfected ticks and <i>A. phagocytophilum</i>-infected ticks. Skin without ticks (intact skin) was used as baseline. RNA was isolated and sequenced using next-generation sequencing (NGS). The differentially expressed genes were used to identify over-represented pathways by gene ontology (GO) and pathway enrichment (PE). <i>Anaplasma phagocytophilum</i> transmission resulted in the activation of interferon signaling and neutrophil chemotaxis pathways in the skin. Interestingly, it also led to the downregulation of genes encoding extracellular matrix (ECM) components, and upregulation of metalloproteinases, suggesting that <i>A. phagocytophilum</i> delays wound healing responses and may increase vascular permeability at the bite site.https://www.mdpi.com/2075-1729/12/12/1965transmissionticksinnate immune responsesmetalloproteinasesextracellular matrixneutrophils
spellingShingle Jacob Underwood
Cristina Harvey
Elizabeth Lohstroh
Branden Pierce
Cross Chambers
Stephanie Guzman Valencia
Adela S. Oliva Chávez
<i>Anaplasma phagocytophilum</i> Transmission Activates Immune Pathways While Repressing Wound Healing in the Skin
Life
transmission
ticks
innate immune responses
metalloproteinases
extracellular matrix
neutrophils
title <i>Anaplasma phagocytophilum</i> Transmission Activates Immune Pathways While Repressing Wound Healing in the Skin
title_full <i>Anaplasma phagocytophilum</i> Transmission Activates Immune Pathways While Repressing Wound Healing in the Skin
title_fullStr <i>Anaplasma phagocytophilum</i> Transmission Activates Immune Pathways While Repressing Wound Healing in the Skin
title_full_unstemmed <i>Anaplasma phagocytophilum</i> Transmission Activates Immune Pathways While Repressing Wound Healing in the Skin
title_short <i>Anaplasma phagocytophilum</i> Transmission Activates Immune Pathways While Repressing Wound Healing in the Skin
title_sort i anaplasma phagocytophilum i transmission activates immune pathways while repressing wound healing in the skin
topic transmission
ticks
innate immune responses
metalloproteinases
extracellular matrix
neutrophils
url https://www.mdpi.com/2075-1729/12/12/1965
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