Antimicrobial and Immunoregulatory Activities of TS40, a Derived Peptide of a TFPI-2 Homologue from Black Rockfish (Sebastes schlegelii)

Abstract

Tissue factor pathway inhibitor-2 (TFPI-2) is a Kunitz-type serine protease inhibitor. Previous reports have shown that TFPI-2 plays an important role in innate immunity, and the C-terminal region of TFPI-2 proved to be active against a broad-spectrum of microorganisms. In this study, the TFPI-2 homologue (SsTFPI-2) of black rockfish (Sebastods schegelii) was analyzed and characterized, and the biological functions of its C-terminal derived peptide TS40 (FVSRQSCMDVCAKGAKQHTSRGNVRRARRNRKNRITYLQA, corresponding to the amino acid sequence of 187-226) was investigated. The qRT-PCR (quantitative real-time reverse transcription-PCR) analysis showed that the expression of SsTFPI-2 was higher in the spleen and liver. The expression of SsTFPI-2 increased significantly under the stimulation of Listonella anguillarum. TS40 had a strong bactericidal effect on L. anguillarum and Staphylococcus aureus. Further studies found that TS40 can destroy the cell structure and enter the cytoplasm to interact with nucleic acids to exert its antibacterial activity. The in vivo study showed that TS40 treatment could significantly reduce the transmission of L. anguillarum and the viral evasion in fish. Finally, TS40 enhanced the respiratory burst ability, reactive oxygen species production and the expression of immune-related genes in macrophages, as well as promoted the proliferation of peripheral blood leukocytes. These results provide new insights into the role of teleost TFPI-2.

Synthetic Antimicrobial Peptides Fail to Induce Leucocyte Innate Immune Functions but Elicit Opposing Transcriptomic Profiles in European Sea Bass and Gilthead Seabream

“…The low toxicity of AMPs has been previously documented, pointing to this feature as a key factor for its use in several fields and among different species [51], and it also occurs in our study. Afterwards, we evaluated their immunomodulatory potential by exposing HK cells to a range of peptide concentrations from 5 to 200 µg/mL for 6 h, according to previous studies in other species [14,35,[52][53][54]. Unfortunately, respiratory burst and phagocytic activities were unaltered by the tested AMPs.…”

“…Similarly, mudskipper (Boleophthamus pectinirostris) macrophages exposed to 1 µg/mL Nkl for 8 h had unaltered phagocytic ability but increased bactericidal ability [13]. Otherwise, the ability of Nkl to enhance the respiratory burst has been described both at shorter (1 h of incubation with 1 µg/mL of peptide) and longer (12 h with 10, 20, 50, and 80 µM) stimulation times in barbel steed (Hemibarbus labeo) and in black rockfish (Sebastes schlegelii), respectively [14,53,54]. The notable differences observed among species might suggest that even if Nkl peptides are highly conserved, the immunomodulation elicited by each peptide can be speciesdependent.…”

Heterologous expression of the insect SVWC peptide WHIS1 inhibits Candida albicans invasion into A549 and HeLa epithelial cells

“…Hence, insects represent a rich source for the discovery of new AMPs. Many studies have confirmed the biological functions of AMPs, such as their anticancer (Bao et al, 2021 ; Timmons and Hewage, 2022 ), antiviral (Liu R. et al, 2022 ; Nabeta et al, 2022 ; Nikyar et al, 2022 ), antibacterial (Maleki Dizaj et al, 2022 ; Wang et al, 2022b ) and immunoregulatory activities (Liu et al, 2018 ; Liu H. et al, 2022 ). There are also some reports on the anti- C. albicans activity of AMPs (Hu et al, 2022 ; Nabeta et al, 2022 ; Peng-Wei et al, 2022 ).…”

Antibacterial Activity and Mechanisms of TroHepc2-22, a Derived Peptide of Hepcidin2 from Golden Pompano (Trachinotus ovatus)

“…The peptide was purified to 96.66% via high performance liquid chromatography (HPLC), and it was identified using mass spectrometry (MS) analysis. The control peptide P86P15 (FKFLDNMAKVAPTEC), which is derived from a viral protein and is usually used as a negative control peptide, was synthesized in a similar manner [35,82,83]. Meanwhile, we synthesized the classical antimicrobial peptide Human hepcidin-25 (Hepc-25) in our studies.…”