Tick feeding modulates the human skin immune landscape to facilitate tick-borne pathogen transmission

Abstract

During cutaneous tick attachment, the feeding cavity becomes a site of transmission for tick salivary compounds and tick-borne pathogens. However, the immunological consequences of tick feeding on human skin remain unclear. Here, we assessed human skin and blood samples upon tick bite and developed a human skin explant model mimicking Ixodes ricinus bite and tick-borne pathogen infection. Following tick attachment, we observed rapidly occurring patterns of immunomodulation including increase in neutrophils and cutaneous B and T cells. T cells up-regulated tissue-residency markers, while lymphocytic cytokine production was impaired.In early stages of Borrelia burgdorferi model infections, we detected strain-specific immune responses and close spatial relationships of macrophages and spirochetes. Pre-incubation of spirochetes with tick salivary gland extracts hampered accumulation of immune cells and increased spirochete loads. Collectively, we showed that tick feeding exerts profound changes on the skin immune network, which interfere with the primary response against tick-borne pathogens.

The tick saliva peptide HIDfsin2 promotes the tick-borne virus SFTSV replication in vitro by enhancing p38 signal pathway

“…There are a variety of complex and biologically active substances in the salivary gland of ticks, which have anticoagulant, anti-inflammatory and immunomodulatory activities. These bioactive molecules can alter the local environment at the bite sites of ticks, and thus they are important factors for ticks to effectively transmit viral, bacterial and protozoan pathogens (Boulanger and Wikel 2021 ; Strobl et al 2022 ). Therefore, an in-depth understanding of the interface reactions at tick bite sites is of great significance for the prevention and treatment of tick-borne diseases.…”

Functional heterogeneity of human skin‐resident memory T cells in health and disease

“…This results in increased transmission of Borrelia burgdorferi in transmission by tick vectors. 119 Similarly, in Aedes aegypti bites, mosquito saliva suppressed proinflammatory responses, resulting in regulatory T cells and Th2 polarization in the skin. 120 In clearance of infection and in wound healing, tissue-resident T regs come into action: Directly following barrier breach, skinresident T regs initially promote inflammation at the keratinocyte layer.…”

“…Interestingly, in some vector‐borne skin infection T RM function may be impaired, as haemophagous pathogen vectors have adapted to prolong feeding by suppressing local immune reactions. This results in increased transmission of Borrelia burgdorferi in transmission by tick vectors 119 . Similarly, in Aedes aegypti bites, mosquito saliva suppressed pro‐inflammatory responses, resulting in regulatory T cells and Th2 polarization in the skin 120 …”

Dermatologie und Venerologie 2021–2022: Eine persönliche Sicht

“…Dabei zeigte sich als Kontrast zu den praktischen klinisch‐organisatorischen Schwierigkeiten der Jahre 2021–2022 erfreuliche Entwicklungen der österreichischen Dermatologie auf dem Gebiet der Wissenschaft. Das breite Spektrum der dermatologischen Krankheiten zeigte sich in den Gebieten, die durch hochrangige Publikationen abgedeckt wurden, wie atopische Dermatitis, Epidermolysis bullosa, T‐Zell Lymphom und Borrelien‐Krankheiten 1–5 . Das wissenschaftliche Alter der jeweiligen Erst‐ und Letztautor:innen zeigt, dass eine neue Generation von Biolog:innen und Clinician Scientists angetreten ist, um in die Fußstapfen eines Phänomens zu treten, das gemeinhin als „Wolff‐Rudel“ bekannt geworden ist (© unklar; aber wahrscheinlich Universität Innsbruck; kürzlich erwähnt bei der Klaus Wolff Vorlesung 2022 während der Jahrestagung der ÖGDV 2022 durch Prof. Gerold Schuler).…”

“…Das breite Spektrum der dermatologischen Krankheiten zeigte sich in den Gebieten, die durch hochrangige Publikationen abgedeckt wurden, wie atopische Dermatitis, Epidermolysis bullosa, T-Zell Lymphom und Borrelien-Krankheiten. [1][2][3][4][5] Das wissenschaftliche Alter der jeweiligen Erst-und Letztautor:innen zeigt, dass eine neue…”