Different Murine High-Risk Corneal Transplant Settings Vary Significantly in Their (Lymph)angiogenic and Inflammatory Cell Signatures

Abstract

Purpose Pathologic conditions in the cornea, such as transplant rejection or trauma, can lead to corneal neovascularization, creating a high-risk environment that may compromise subsequent transplantation. This study aimed to evaluate the impact of different types of corneal injury on hemangiogenesis (HA), lymphangiogenesis (LA) and immune cell pattern in the cornea. Methods We used five different corneal injury models, namely, incision injury, alkali burn, suture placement, and low-risk keratoplasty, as well as high-risk keratoplasty and naïve corneas as control. One week after incision and 2 weeks after all other different injuries, corneal HA and LA were quantified by morphometric analysis. In addition, immune cell patterns of the whole cornea and the recipient rim were analyzed by immunohistochemistry. Immune cells in the draining lymph nodes (dLNs) were quantified by flow cytometry. Results Different types of corneal injury caused significantly different HA and LA responses (both P < 0.0001). The infiltration of corneal macrophages, dendritic cells, neutrophils, major histocompatibility complex (MHC) II + cells, CD4 + T cells, and CD8 + T cells varied significantly in different high-risk settings (all P < 0.0001). Both the expression of MHC II on macrophages ( P = 0.0005) and the frequency of MHC II + dendritic cells ( P = 0.0014) in the draining lymph nodes were significantly different across the various high-risk scenarios. Conclusions Murine high-risk settings caused by different underlying pathologies vary significantly in their (lymph)angiogenic and inflammatory cell patterns. Therefore, anti(lymph)angiogenic or immunomodulatory strategies to prevent and/or treat immune responses after subsequent corneal transplantation may need to be customized according to their immune-vascular “signatures.”

New targets of nascent lymphatic vessels in ocular diseases

“…Alkali burns have also been used as a modeling tool to induce inflammatory lymphangiogenesis. Zhang et al's experiments in the murine model of incision injury, alkali burn, suture placement, low-risk keratoplasty, and high-risk keratoplasty revealed that corneal alkali burns produced fewer nascent lymphatic vessels than suture and graft burn wounds but significantly more nascent lymphatic vessels than incision burns ( Zhang et al, 2022b ).…”

Lymphangiogenesis Guidance Mechanisms and Therapeutic Implications in Pathological States of the Cornea

“…Different methods of corneal injury can induce vastly different inflammatory profiles including various degrees of lymphangiogenesis [207]. Corneal alkali burns induce a relatively modest lymphangiogenic response compared to keratoplasty and suture placement but a stronger response than incision [207].…”

“…Different methods of corneal injury can induce vastly different inflammatory profiles including various degrees of lymphangiogenesis [207]. Corneal alkali burns induce a relatively modest lymphangiogenic response compared to keratoplasty and suture placement but a stronger response than incision [207]. In a direct comparison between suture-induced and alkali burn-induced corneal inflammation, alkali burn produced a less pronounced lymphangiogenic response but a similar hemangiogenic response, indicating that differences in the method of induction of inflammation may be significant for corneal lymphangiogenesis [208].…”