Seybold, A. C. | Search bioRxiv

bioRxiv2025

Amphibian-derived peptide analog TB_KKG6K: A powerful drug candidate against Candida albicans with anti-biofilm efficacy

Candida albicans, a commensal and opportunistic fungal pathogen, is a major clinical concern due to its ability to cause infections ranging from mild mucosal conditions to life-threatening systemic diseases, particularly in immunocompromised patients. Its capacity to form biofilms on medical devices further complicates treatment by enhancing antifungal resistance and immune evasion. In the search for novel therapeutic strategies, the lysine-enriched amphibian-derived temporin B analog, TB_KKG6K, has emerged as a promising antifungal agent. This study demonstrates that TB_KKG6K exhibits potent activity against planktonic C. albicans cells, with a low potential to induce adaptation or resistance, even after prolonged exposure. TB_KKG6K has no adverse impact on the anti-Candida efficacy of standard antifungal drugs like amphotericin B, caspofungin, fluconazole or 5-flucytosine, when applied in combination. Additionally, TB_KKG6K effectively reduces biofilm maturation on silicone elastomers, a material commonly used in medical devices, further highlighting its therapeutic potential. These data together with our previous documentation of minimal cytotoxicity and irritation potential in human cells, makes TB_KKG6K a strong candidate for combating both planktonic and biofilm-associated C. albicans infections. These findings underscore the dual efficacy of TB_KKG6K and its potential to address the challenges posed by C. albicans in clinical settings.

microbiology↗

bioRxiv2025

Ectopic head regeneration after nervous system ablation in a sea anemone

Some animals are able to regenerate all missing cell types and large body parts after bisection, a phenomenon called whole-body regeneration. Many of these animals regenerate the correct tissues and structures with remarkable fidelity according to the original polarity of the body, reflecting positional information present in the remaining tissue. Understanding the cellular and molecular basis of this positional information is a central question in regeneration biology. In planarians and acoels, muscle cells have been shown to carry such positional information, but where this information originates and whether this function is conserved in other highly regenerative animals, is not well understood. Here we use the cnidarian Nematostella vectensis to address the role of the nervous system in whole-body regeneration. We generated a transgenic line for conditional ablation of neurons and first showed that Nematostella can repeatedly regenerate its nervous system. Bisection experiments following nervous system ablation showed that all head fragments regenerate a second head instead of a foot, whereas foot fragments correctly regenerate the missing head. We further found that regenerating head fragments of nervous system-ablated animals increase the expression of Wnt signaling genes that in wildtype animals are only upregulated in regenerating foot fragments. These molecular changes and the initiation of ectopic head regeneration precede the re-appearance of neurons, suggesting that the nervous system does not directly control whether a head or foot will be regenerated. Instead, we propose a model in which the nervous system provides positional information to the tissue of the body column, and that this information allows foot regeneration by suppressing a default program for head regeneration.

developmental biology↗