Talactoferrin stimulates wound healing with modulation of inflammation.

BACKGROUND: Inflammation is an acute, early process during normal wound healing. Talactoferrin, a recombinant human lactoferrin, can induce the secretion of inflammatory mediators. MATERIALS AND METHODS: We measured wound healing activity of topical talactoferrin in full-thickness wounds of normal mice and diabetic (db(-)/db(-)) mice, systemic bioavailability, and the potential to modulate inflammation through in vitro and in vivo binding assays and inflammatory mediator measurements. RESULTS: Talactoferrin significantly increased the closure rate during 12 to 19 d (maximally on d 3 to 6), the 75% closure incidence, and the time to 50% closure versus vehicle or becaplermin (recombinant human platelet-derived growth factor). Systemic bioavailability was less than 0.5% following administration to open wounds. Talactoferrin bound local dermal cells in vivo and human dermal fibroblasts in vitro, and it induced the migration of dermal fibroblasts, THP-1 macrophages, Jurkat T cells, and mouse granulocytes in vitro. Competition binding assays suggested the involvement of IL-8RB and CCR2 chemokine receptors in binding and/or cell migration. Consistently, the induction of migration was partially inhibited in interleukin (IL)-8RB deficient granulocytes. Talactoferrin also enhanced the production of key repair inflammatory mediators IL-8, IL-6, macrophage inflammatory protein-1 alpha, and tumor necrosis factor alpha in d 3 wounds, and IL-8, IL-6, and monocyte chemotactic protein-1 in cultured dermal fibroblasts. CONCLUSION: Talactoferrin promotes wound repair in vivo, correlating with a modulated enhancement of the early inflammatory phase of wound healing. Based on this data, talactoferrin was subsequently tested clinically in a Phase II trial in patients with diabetic ulcers and was found to be effective and safe. Talactoferrin should be further evaluated in patients with diabetic and other types of ulcers.

Requirement for IFN-gamma, CD8+ T lymphocytes, and NKT cells in talactoferrin-induced inhibition of neu+ tumors.

We have previously shown that talactoferrin-alfa (TLF), a recombinant human lactoferrin, is an immunomodulatory protein that is active against implanted tumors, both as a single agent and in combination with chemotherapy. In this study, we show that talactoferrin is active against autochthonous tumors in a transgenic mouse line, which is more analogous to human cancers, and identify key mechanistic steps involved in the anticancer activity of oral TLF. BALB/c mice transgenic for the rat neu (ErbB2) oncogene (BALB-neuT) treated with oral TLF showed a significant delay in carcinogenesis, with 60% tumor protection relative to vehicle-treated mice at week 21. Oral TLF also showed tumor growth inhibition in wild-type BALB/c mice implanted with neu(+) mammary adenocarcinoma, with one third displaying a long-lasting or complete response. Oral TLF induces an increase in intestinal mucosal IFN-gamma production and an increase in Peyer's patch cellularity, including expansion of CD8(+) T lymphocytes and NKT cells, and the enhancement of CD8(+) T-cell cytotoxicity. In IFN-gamma knockout mice, there is an absence of the TLF-induced Peyer's patch cellularity, no expansion of CD8(+) T lymphocytes and NKT cells, and loss of TLF anticancer activity. TLF antitumor activity is also lost in mice depleted of CD8(+) T cells and in CD1 knockout mice, which lack NKT activity. Thus, the inhibition of distant tumors by oral TLF seems to be mediated by an IFN-gamma-dependent enhancement of CD8(+) T- and NKT cell activity initiated within the intestinal mucosa.