1. Prothymosin α and its C-Terminal Immunoreactive Decapeptide Show No Evidence of Acute Toxicity: A Preliminary In Silico, In Vitro and In Vivo Investigation
- Author
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Margarita Skopeliti, David Toukli, Eleftheria Klagkou, Anastasios I. Birmpilis, Panagiotis Vitsos, Themis Gkraikou, Wolfgang Voelter, Hubert Kalbacher, Nikolaos Angelis, Pinelopi Samara, Niki Kappa, Ourania E. Tsitsilonis, Persefoni Klimentzou, Nikos E. Papaioannou, Elena Alyfanti, Spiridoula Nikou, Kyriaki Ioannou, Meletios-Athanasios Dimopoulos, Chrysoula-Evangelia Karachaliou, Nikolaos G. Gavalas, Ioannis Kostopoulos, Ioannis F. Voutsas, Lillian Williams, Evangelia Livaniou, and Aristotelis Bamias
- Subjects
Pharmacology ,Chemistry ,In silico ,Organic Chemistry ,Cell cycle ,Prothymosin Alpha ,Biochemistry ,In vitro ,Proinflammatory cytokine ,In vivo ,Cell culture ,Drug Discovery ,Cancer cell ,Molecular Medicine - Abstract
Background: Members of the α-thymosin family have long been studied for their immunostimulating properties. Among them, the danger-associated molecular patterns (DAMPs) prothymosin α (proTα) and its C-terminal decapeptide proTα(100–109) have been shown to act as immunomodulators in vitro, due to their ability to promote T helper type 1 (Th1) responses. Recently, we verified these findings in vivo, showing that both proTα and proTα(100-109) enhance antitumor-reactive T cell-mediated responses. Methods: In view of the eventual use of proTα and proTα(100-109) in humans, we investigated their safety profile in silico, in human leukocytes and cancer cell lines in vitro, and in immunocompetent mice in vivo, in comparison to the proTα derivative thymosin alpha 1 (Τα1), a 28-mer peptide extensively studied for its safety in clinical trials. Results: In silico prediction via computational tools showed that all three peptide sequences likely are non-toxic or do not induce allergic regions. In vitro, pro- Tα, proTα(100-109) and Tα1 did not affect the viability of human cancer cell lines and healthy donor-derived leukocytes, did not promote apoptosis or alter cell cycle distribution. Furthermore, mice injected with proTα, proTα(100-109) and Tα1 at doses equivalent to the suggested dose regimen of Tα1 in humans, did not show signs of acute toxicity, whereas proTα and proTα(100-109) increased the levels of proinflammatory and Th1- type cytokines in their peripheral blood. Conclusion: Our preliminary findings suggest that proTα and proTα(100-109), even at high concentrations, are non-toxic in vitro and in an acute toxicity model in vivo; moreover, we show that the two peptides retain their immunomodulatory properties in vivo and, eventually, could be considered for therapeutic use in humans.
- Published
- 2022