Reparative Outcomes in Corneal Infection: Linking Adjunctive Tβ4 Treatment to Nerve Regeneration and Visual Function. — VialBase Research

Summary

This animal study tested whether adding thymosin β4 (Tβ4) to antibiotic treatment improves nerve and vision outcomes after corneal infection. Bacterial keratitis was induced in C57BL/6 mice with Pseudomonas aeruginosa, then treated topically three times daily with PBS, Tβ4 alone, ciprofloxacin alone, or adjunctive Tβ4 + ciprofloxacin, beginning 24 hours after infection. The combination therapy markedly improved visual acuity and contrast sensitivity and enhanced corneal sensitivity and nerve regeneration versus each monotherapy, restoring nerve density and architecture toward uninfected-control levels. Tβ4 is the full-length parent peptide of the synthetic fragment TB-500.

Key Findings

• Bacterial keratitis was induced in C57BL/6 mice by inoculating wounded corneas with Pseudomonas aeruginosa (ATCC strain 19660); topical PBS, Tβ4 monotherapy, ciprofloxacin monotherapy, or adjunctive Tβ4 + ciprofloxacin was administered three times daily starting 24 hours post infection.
• Adjunctive Tβ4 + ciprofloxacin markedly improved visual acuity (cycles/degree) and contrast sensitivity (%) compared with PBS, Tβ4 monotherapy, and ciprofloxacin monotherapy.
• Combination therapy significantly enhanced corneal sensitivity and nerve regeneration relative to the monotherapies, quantified via corneal sensitivity testing and β-III tubulin immunofluorescence in corneal flat mounts.
• The combination restored corneal nerve density and architecture to levels comparable to those of uninfected controls.

Relevance to TB-500

TB-500 is the synthetic acetylated fragment of thymosin β4 (Tβ4), so preclinical work on Tβ4’s tissue-repair biology speaks directly to the rationale behind TB-500. This study adds a specific, functionally meaningful endpoint to that literature: adjunctive Tβ4 did not merely reduce infection severity but restored corneal nerve integrity and measurable visual function that antibiotic alone did not, positioning Tβ4 as a repair-promoting adjunct rather than a stand-alone antimicrobial. The nerve-regeneration signal is notable because it aligns with the broader regenerative framing that Tβ4-derived peptides share with other repair-oriented peptides such as BPC-157. As a mouse study without reported human dosing or long-term safety data, it informs mechanism and rationale rather than clinical use.

Citation

Ebrahim AS, Liu L, Carion TW, et al. Reparative Outcomes in Corneal Infection: Linking Adjunctive Tβ4 Treatment to Nerve Regeneration and Visual Function. Investigative ophthalmology & visual science. 2026. doi:10.1167/iovs.67.6.22.

See Also

• Parent compound: TB-500
• BPC-157