Antimicrobial Role of RNASET2 Protein During Innate Immune Response in the Medicinal Leech
Research article published in Frontiers in immunology (2020)
Abstract
The innate immune response represents a first-line defense against pathogen infection that has been widely conserved throughout evolution. Using the invertebrate Hirudo verbana (Annelida, Hirudinea) as an experimental model, we show here that the RNASET2 ribonuclease is directly involved in the immune response against Gram-positive bacteria. Injection of lipoteichoic acid (LTA), a key component of Gram-positive bacteria cell wall, into the leech body wall induced a massive migration of granulocytes and macrophages expressing TLR2 (the key receptor involved in the response to Gram-positive bacteria) toward the challenged/inoculated area. We hypothesized that the endogenous leech RNASET2 protein (HvRNASET2) might be involved in the antimicrobial response, as already described for other vertebrate ribonucleases, such as RNase3 and RNase7. In support of our hypothesis, HvRNASET2 was mainly localized in the granules of granulocytes, and its release in the extracellular matrix triggered the recruitment of macrophages toward the area stimulated with LTA. The activity of HvRNASET2 was also evaluated on Staphylococcus aureus living cells by means of light, transmission, and scanning electron microscopy analysis. HvRNASET2 injection triggered the formation of S. aureus clumps following a direct interaction with the bacterial cell wall, as demonstrated by immunogold assay. Taken together, our data support the notion that, during the early phase of leech immune response, granulocyte-released HvRNASET2 triggers bacterial clumps formation and, at the same time, actively recruits phagocytic macrophages in order to elicit a rapid and effective eradication of the infecting microorganisms from inoculated area.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Resumen
The innate immune response represents a first-line defense against pathogen infection that has been widely conserved throughout evolution.
Por qué esto importa para la hirudoterapia
Este estudio examinó el papel de la ribonucleasa endógena HvRNASET2 en la respuesta inmunitaria innata de la sanguijuela medicinal Hirudo verbana frente a bacterias Gram-positivas, demostrando que la proteína se almacena en los gránulos de los granulocitos, se libera tras el estímulo con ácido lipoteicoico, recluta macrófagos e induce la agregación de Staphylococcus aureus mediante interacción directa con la pared celular. Para la hirudoterapia y el ámbito de la ASH, este trabajo es directamente relevante porque caracteriza un mecanismo de defensa antimicrobiana intrínseco en la misma especie utilizada clínicamente, informando nuestra comprensión de cómo las sanguijuelas medicinales resisten naturalmente la colonización bacteriana, una consideración importante dado el riesgo de infección asociado con la terapia con sanguijuelas. Los hallazgos también pueden estimular el interés por si el RNASET2 derivado de sanguijuelas o componentes salivales relacionados poseen propiedades antimicrobianas aprovechables. Sin embargo, el estudio es experimental y se limita a la biología inmunitaria propia de la sanguijuela; no evalúa la eficacia terapéutica en contextos mamíferos o clínicos, ni demuestra que HvRNASET2 se secreta en la saliva a concentraciones funcionalmente relevantes durante la alimentación o la terapia.
Citación
Antimicrobial Role of RNASET2 Protein During Innate Immune Response in the Medicinal Leech
Baranzini N et al. · Frontiers in immunology, 2020
Contexto clínico relacionado
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Añadido a la biblioteca ASH: March 18, 2026 · Última actualización del sitio: June 18, 2026