Tick innate immunity involves humoral and cellular responses. Among the humoral effector molecules in ticks are the defensins which are a family of small peptides with a conserved γ-core motif that is crucial for their antimicrobial activity. Defensin families have been identified in several hard and soft tick species. However, little is known about the presence and antimicrobial activity of defensins from the Australian paralysis tick Ixodes holocyclus. In this study the I. holocyclus transcriptome was searched for the presence of defensins. Unique and non-redundant defensin sequences were identified and designated as holosins 1 - 5. The antimicrobial activity of holosins 2 and 3 and of the predicted γ-cores of holosins 1-4 (HoloTickCores 1-4), was assessed using Gram-negative and Gram-positive bacteria as well as the fungus Fusarium graminearum and the yeast Candida albicans. All holosins had molecular features that are conserved in other tick defensins. Furthermore holosins 2 and 3 were very active against the Gram-positive bacteria Staphylococcus aureus and Listeria grayi. Holosins 2 and 3 were also active against F. graminearum and C. albicans and 5 μM of peptide abrogate the growth of these microorganisms. The activity of the synthetic γ-cores was lower than that of the mature defensins apart from HoloTickCore 2 which had activity comparable to mature holosin 2 against the Gram-negative bacterium Escherichia coli. This study reveals the presence of a multigene defensin family in I. holocyclus with wide antimicrobial activity.

• MeSH
• antibakteriální látky chemie   farmakologie   MeSH
• antifungální látky chemie   farmakologie   MeSH
• Candida albicans účinky léků   MeSH
• defensiny chemie   genetika   imunologie   MeSH
• Fusarium účinky léků   MeSH
• fylogeneze MeSH
• gramnegativní bakterie účinky léků   MeSH
• grampozitivní bakterie účinky léků   MeSH
• klíště genetika   imunologie   MeSH
• proteiny členovců chemie   genetika   imunologie   MeSH
• sekvence aminokyselin MeSH
• sekvenční seřazení MeSH
• transkriptom MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Austrálie MeSH

Tick-borne infectious diseases and allergies are a growing problem worldwide. Tick bite allergy has been associated with the direct effect of immunoglobulin E (IgE) response to tick salivary antigens, or secondary to the induction of allergy to red meat consumption through IgE antibodies against the carbohydrate α-Gal (Gal α 1-3Gal β 1-(3)4GlcNAc-R). However, despite the growing burden of this pathology, the proteins associated with anaphylaxis to tick bite have not been characterized. To address this question, a comparative proteomics approach was used to characterize tick proteins producing an IgE antibody response in a healthy individual with record of tick bites, which had not resulted in any allergic reactions, and two patients with anaphylactic reactions to Rhipicephalus bursa or Hyalomma marginatum tick bites. Both patients and the healthy individual were red meat tolerant. The results supported a patient-specific IgE antibody response to tick species responsible for the anaphylaxis to tick bite. Both patients and the healthy individual serologically recognized tick proteins with and without α-Gal modifications, with proteins differentially recognized by patients but not control sera. These proteins could be used as potential antigens for diagnostics, treatment and prevention of tick bite-induced allergies.

• MeSH
• 2D gelová elektroforéza MeSH
• anafylaxe imunologie   MeSH
• antigeny imunologie   MeSH
• imunoglobulin E imunologie   MeSH
• klíšťata imunologie   MeSH
• kousnutí klíštětem komplikace   imunologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• proteiny členovců imunologie   MeSH
• proteomika MeSH
• western blotting MeSH
• zvířata MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH