Institute of Animal Science, University of Hohenheim, 70599 Stuttgart, Germany.
Institute of Animal Science, University of Hohenheim, 70599 Stuttgart, Germany.
Poult Sci. 2021 Nov;100(11):101408. doi: 10.1016/j.psj.2021.101408. Epub 2021 Jul 24.
During life, the number and function of immune cells change with potential consequences for immunocompetence of an organism. In laying hens, studies have primarily focused on early development of immune competence and only few have investigated systemic and lymphatic distribution of leukocyte subsets during adolescence and the egg-laying period. The present study determined the number of various leukocyte types in blood, spleen, and cecal tonsils of 10 Lohmann Brown-Classic and 10 Lohmann LSL-Classic hens per wk of life 9/10, 15/16, 23/24, 29/30, and 59/60, encompassing important production as well as developmental stages, by flow cytometry. Although immune traits differed between the 2 hen strains, identical patterns of age-related immunological changes were found. The numbers of all investigated lymphocyte types in the spleen as well as the numbers of blood γδ T cells increased from wk 9/10 to 15/16. This suggests an ongoing release of lymphocytes from primary lymphoid tissues and an influx of blood lymphocytes into the spleen due to novel pathogen encounters during adolescence. A strong decrease in the number of CTL and γδ T cells and an increase in innate immune cells within blood and spleen were found between wk of life 15/16 and 23/24, covering the transition phase to egg-laying activity. Numbers of peripheral and splenic lymphocytes remained low during the egg-laying period or even further decreased, for example blood CD4 T cells and splenic γδ T cells. Functional assessments showed that in vitro IFN-γ production of mitogen-stimulated splenocytes was lower in wk 60. Taken together, egg-laying activity seems to alter the immune system toward a more pronounced humoral and innate immune response, with probable consequences for the immunocompetence and thus for productivity, health and welfare of the hens.
在生命过程中，免疫细胞的数量和功能会发生变化，这可能对生物体的免疫能力产生影响。在产蛋母鸡中，研究主要集中在免疫能力的早期发展上，只有少数研究调查了青春期和产蛋期全身和淋巴系统白细胞亚群的分布。本研究通过流式细胞术确定了 10 只 Lohmann Brown-Classic 和 10 只 Lohmann LSL-Classic 母鸡在生命第 9/10、15/16、23/24、29/30 和 59/60 周时血液、脾脏和盲肠扁桃体中各种白细胞类型的数量，这些周龄涵盖了重要的生产和发育阶段。尽管两种母鸡品系的免疫特征不同，但发现了相同的与年龄相关的免疫变化模式。从第 9/10 周到 15/16 周，脾脏中所有被调查的淋巴细胞类型以及血液 γδ T 细胞的数量增加。这表明由于青春期新病原体的出现，淋巴细胞从初级淋巴组织释放，并向脾脏输入血液淋巴细胞。在生命第 15/16 周到 23/24 周之间，发现 CTL 和 γδ T 细胞的数量急剧减少，血液和脾脏中的固有免疫细胞数量增加，这是向产蛋活动过渡的阶段。在产蛋期间，外周和脾脏淋巴细胞的数量保持较低水平，甚至进一步减少，例如血液 CD4 T 细胞和脾脏 γδ T 细胞。功能评估表明，在第 60 周时，有丝分裂原刺激的脾细胞体外 IFN-γ 的产生较低。总之，产蛋活动似乎使免疫系统向更明显的体液和固有免疫反应转变，这可能对母鸡的免疫能力和生产力、健康和福利产生影响。
