Yolkin is a product of proteolytic degradation of vitellogenin, a protein contained in eggs' yolk, with already described procognitive properties. Here, we investigated effects of yolkin on the humoral and cellular immune response in mice, phenotype of cells from lymphoid organs and function of innate immunity cells. In vitro studies included effects of yolkin on mitogen-induced thymocyte proliferation, percentage of CD19 cells in bone marrow cells culture, expression of signaling molecules in Jurkat cells, interleukin 2 receptor (IL-2R) subunits in WEHI 231 cells and susceptibility of these cells to anti-Ig-induced cell death. The results showed that repeatable i.p. injections of yolkin stimulated the humoral immune response to sheep red blood cells (SRBC) irrespective of the time of the treatment. On the other hand, yolkin inhibited contact sensitivity to oxazolone. Treatment of mice with yolkin diminished the percentage of double positive cells and increasing the content of single positive CD4+ and CD8+ cells in the thymus. At the same time an increase of percentage of CD19 + B cells in the spleen and mesenteric lymph nodes was observed. In addition, the protein, given i.p., diminished ex vivo ability to synthesize nitric oxide by resident, peritoneal macrophages, stimulated with lipopolisaccharide (LPS). In vitro studies showed that yolkin increased CD19+ cell content in bone marrow cell population. The protein also enhanced proliferation of thymocytes to concanavalin A and stimulated expression of MAP kinases in Jurkat cells. In WEHI 231 B cell line yolkin caused a loss of IL-2R gamma chain expression, correlated with an increased resistance of these cells to proapoptotic action of anti-Ig antibodies. In conclusion, this is a first demonstration of immunotropic properties of yolkin in in vitro and in vivo tests. The results provide evidence for induction of maturation and stimulatory signals in immature T and B cells by the protein, suggesting its potential role in the development of an embryo's immune system.

中文翻译：

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洋金对小鼠免疫反应的影响及其可能的作用机制。

卵黄蛋白是卵黄蛋白原的蛋白水解降解产物，卵黄蛋白原是蛋黄中的一种蛋白质，具有已描述的认知特性。在这里，我们调查了洋金对小鼠体液和细胞免疫反应，淋巴器官细胞表型和先天免疫细胞功能的影响。体外研究包括约尔金对丝裂原诱导的胸腺细胞增殖的影响，骨髓细胞培养物中CD19细胞的百分比，Jurkat细胞中信号分子的表达，WEHI 231细胞中白介素2受体（IL-2R）亚基的表达以及这些细胞的敏感性抗Ig诱导的细胞死亡。结果表明，与处理时间无关，可重复腹腔注射约尔金刺激了对绵羊红细胞（SRBC）的体液免疫反应。另一方面，约金抑制了对恶唑酮的接触敏感性。用约尔金（yolkin）处理小鼠可减少胸腺中双阳性细胞的百分比并增加单阳性CD4 +和CD8 +细胞的含量。同时观察到脾脏和肠系膜淋巴结中CD19 + B细胞的百分比增加。此外，腹膜内给予的蛋白质降低了通过脂多糖（LPS）刺激的常驻腹膜巨噬细胞合成一氧化氮的离体能力。体外研究表明，约尔金增加了骨髓细胞群中CD19 +细胞的含量。该蛋白还增强了胸腺细胞向伴刀豆球蛋白A的增殖，并刺激了Jurkat细胞中MAP激酶的表达。在WEHI 231 B细胞系中，约金引起IL-2Rγ链表达的丧失，这些细胞与抗Ig抗体促凋亡作用的抗性增加有关。总而言之，这是洋金蛋白在体外和体内测试中的免疫特性的首次证明。该结果提供了该蛋白质诱导未成熟T和B细胞成熟和刺激信号的证据，表明其在胚胎免疫系统发育中的潜在作用。