Division of Nutritional Sciences, University of Illinois, Urbana, Illinois.
Pediatr Res. 2013 Oct;74(4):402-7. doi: 10.1038/pr.2013.125. Epub 2013 Jul 18.
Natural killer (NK) cells are components of the innate immune defense system, and their levels differ between breast and formula-fed (FF) infants. Lactoferrin (Lf) modulates NK cell cytotoxicity ex vivo. We hypothesized that dietary bovine Lf (bLf) would increase NK cell populations and cytotoxicity.
Piglets were sow-reared (SR), FF, or 1 g/l bLf-fed (LF) for 21 d. NK cells (CD3(-)CD4(-)CD8(+)) in blood (peripheral blood mononuclear cells (PBMCs)), spleen, and mesenteric lymph node (MLN) were determined by flow cytometry. PBMC NK cells were tested for cytotoxic activity against target K562 cells ex vivo in the presence of media (unstimulated), interleukin-2, or bLf. NK cell mRNA expression was determined by reverse transcription-quantitative PCR.
SR and LF piglets had more NK cells in MLN (P = 0.0097) and spleen (P = 0.0980) than FF piglets. In PBMCs, SR piglets had more NK cells than FF piglets (P = 0.0072); LF piglets were intermediate and not different from FF or SR piglets. NK cell intelectin-2 mRNA expression was 2.5-fold higher (P = 0.0095) in LF than SR or FF piglets. NK cells in SR piglets exhibited greater (P < 0.0001) cytotoxic activity than those in LF or FF piglets, which was supported by greater perforin mRNA expression.
Dietary bLf increased blood NK cell populations and NK Lf receptor expression but not NK cell cytotoxicity.
自然杀伤 (NK) 细胞是先天免疫防御系统的组成部分，其水平在母乳喂养和配方奶喂养的婴儿之间存在差异。乳铁蛋白 (Lf) 可调节 NK 细胞的细胞毒性。我们假设膳食牛乳铁蛋白 (bLf) 会增加 NK 细胞的数量和细胞毒性。
仔猪通过母猪喂养 (SR)、配方奶喂养 (FF) 或 1g/L bLf 喂养 (LF) 21 天。通过流式细胞术测定血液（外周血单核细胞 (PBMCs)）、脾脏和肠系膜淋巴结 (MLN) 中的 NK 细胞（CD3(-)CD4(-)CD8(+)）。在存在培养基（未刺激）、白细胞介素-2 或 bLf 的情况下，体外检测 PBMC NK 细胞对靶细胞 K562 的细胞毒性。通过逆转录定量 PCR 测定 NK 细胞的 mRNA 表达。
SR 和 LF 仔猪的 MLN（P = 0.0097）和脾脏（P = 0.0980）中的 NK 细胞多于 FF 仔猪。在 PBMCs 中，SR 仔猪的 NK 细胞多于 FF 仔猪（P = 0.0072）；LF 仔猪处于中间水平，与 FF 或 SR 仔猪没有差异。LF 仔猪的 NK 细胞凝集素-2 mRNA 表达比 SR 或 FF 仔猪高 2.5 倍（P = 0.0095）。SR 仔猪的 NK 细胞表现出更强的细胞毒性（P < 0.0001），这与穿孔素 mRNA 表达更高有关。
膳食 bLf 增加了血液 NK 细胞的数量和 NK Lf 受体的表达，但没有增加 NK 细胞的细胞毒性。
