Interleukin-8 (IL-8) is a potent inflammatory chemokine, and two gene promoter haplotypes have been previously reported to segregate in cattle populations. Our earlier work showed how these divergent IL8 genotypes influence IL-8 expression and other immune response parameters at a systemic level. Here we extend that work to characterise the influence of haplotype on the local immune response – in primary bovine dermal fibroblasts. Furthermore, we also investigated how this response is modulated by 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃). Significant induction of IL8 expression was observed in cells from both haplotypes at 3 and 24 h post-stimulation with the TLR1/2 ligand, Pam3CSK4 and with the TLR4 ligand, LPS. IL8 expression was elevated in response to both LPS and Pam3CSK4 in fibroblasts carrying the IL8-h1 haplotype and this result was supported by significantly enhanced IL-8 protein secretion. Gene expression profiles for other known fibroblast immune mediators (SAA3 and CCL20) did not show significant differences between haplotypes but NOS2 gene expression was significantly elevated in response to vitamin D, even above the level detected in response to both TLR ligands. In conclusion, this work has demonstrated that the IL-8 response of dermal fibroblasts is dependent on IL8 haplotype and that the immune response profile in these cells is significantly differentially regulated by 1,25(OH)₂D₃. Fibroblasts have important immune response capacity and their function in driving inflammatory responses (including iNOS) is underappreciated. Understanding the relationship between cattle genotype and immune function is critically important for uncovering sustainable solutions for animal disease.

白细胞介素 8 (IL-8) 是一种有效的炎症趋化因子，之前已经报道了两种基因启动子单倍型在牛群中分离。我们早期的工作显示了这些不同的 IL8 基因型如何在全身水平上影响 IL-8 表达和其他免疫反应参数。在这里，我们扩展了这项工作，以表征单倍型对局部免疫反应的影响——在原代牛真皮成纤维细胞中。此外，我们还研究了 1,25-二羟基维生素 D ₃ (1,25(OH) ₂ D ₃ )如何调节这种反应。在用 TLR1/2 配体 Pam3CSK4 和 TLR4 配体 LPS 刺激后 3 和 24 小时，在来自两种单倍型的细胞中观察到IL8表达的显着诱导。IL8在携带 IL8-h1 单倍型的成纤维细胞中，LPS 和 Pam3CSK4 的表达均升高，这一结果得到 IL-8 蛋白分泌显着增强的支持。其他已知成纤维细胞免疫介质（SAA3和CCL20）的基因表达谱没有显示单倍型之间的显着差异，但NOS2基因表达响应维生素 D 显着升高，甚至高于响应两种 TLR 配体检测到的水平。总之，这项工作已经证明真皮成纤维细胞的 IL-8 反应依赖于 IL8 单倍型，并且这些细胞中的免疫反应谱受到 1,25(OH) ₂ D _{3 的}显着差异调节. 成纤维细胞具有重要的免疫反应能力，但它们在驱动炎症反应（包括 iNOS）方面的功能被低估了。了解牛基因型与免疫功能之间的关系对于发现动物疾病的可持续解决方案至关重要。