Department of pathology, College of Veterinary Medicine, Gansu Agricultural University, Lanzhou, China.
PLoS One. 2023 Mar 22;18(3):e0279417. doi: 10.1371/journal.pone.0279417. eCollection 2023.
Gastrointestinal associated lymphoid tissue (GALT) is an important component of the mucosal immune system. It is the largest mass of lymphoid tissues in the body and makes up more than 70% immune cells of entire body. GALT is considered to be the origin of systemic mucosal immunity and consists of solitary lymphoid nodules, aggregated lymphoid nodules (Peyer's patches, PPs), scattered lymphoid tissues, and follicular associated epithelia. PPs play important roles as antigen inductive sites of the mucosal immune system, which are mainly distributed in the intestine of animals and humans (especially ileum and appendix). However, a special area of well-developed aggregated lymphoid nodules in the abomasum of Dromedary camel was found in our laboratory. Its existence was rarely described in the stomach before. In the present study, we investigated this special structure with the dromedary camels of different ages (young, 0.5-2 years; pubertal, 3-5 years; middle-aged, 6-16 years; old, 17-20 years), by the anatomical, histological and immunohistochemical approaches. The results showed that the special structure was mainly distributed in the cardiac glandular area of the abomasum, forming a triangular area. The mucosal folds in this area were significantly thicker than those in the surrounding region. These mucosal folds had two different forms, namely reticular mucosal folds (RMF) and longitudinal mucosal folds (LMF). There were abundant lymphoid nodules in the submucosa of RMF and LMF, which were arranged in one or multiple rows. The statistical analysis of the height and thickness of RMF and LMF showed that the structure was most developed in pubertal dromedary camels. The histological characteristics of the structure were the same as PPs in the intestine of the Dromedary camel, while anatomical appearance showed some difference. The immunohistochemical examination revealed that both immunoglobulin A (IgA) and G (IgG) antibodies-producing cells (APCs) were extensively distributed in the gastric lamina propria (LP) in all age group. Our finding suggest that camel stomach not only performs digestive functions, but also involves parts of body immunity.
胃肠道相关淋巴组织（GALT）是黏膜免疫系统的重要组成部分。它是体内最大的淋巴组织群，构成了全身 70%以上的免疫细胞。GALT 被认为是全身黏膜免疫的起源，由孤立淋巴小结、聚集淋巴小结（派尔集合淋巴结，PPs）、散在淋巴组织和滤泡相关上皮组成。PPs 在黏膜免疫系统中作为抗原诱导部位发挥重要作用，主要分布在动物和人类的肠道（特别是回肠和阑尾）。然而，我们实验室在单峰驼的皱胃中发现了一个特殊的、发达的聚集淋巴小结区域。在此之前，胃中很少有关于这种特殊结构的描述。在本研究中，我们通过解剖学、组织学和免疫组织化学方法，对不同年龄（幼龄，0.5-2 岁；性成熟，3-5 岁；中年，6-16 岁；老年，17-20 岁）的单峰驼进行了研究。结果表明，该特殊结构主要分布在皱胃的贲门腺区，形成一个三角形区域。该区域的黏膜皱襞明显比周围区域厚。这些黏膜皱襞有两种不同的形式，即网状黏膜皱襞（RMF）和纵向黏膜皱襞（LMF）。在 RMF 和 LMF 的黏膜下层有丰富的淋巴小结，呈单行或多行排列。RMF 和 LMF 高度和厚度的统计学分析表明，该结构在性成熟的单峰驼中发育最为完善。该结构的组织学特征与单峰驼肠道中的 PPs 相同，但解剖外观存在一些差异。免疫组织化学检查显示，在所有年龄组的胃固有层（LP）中，免疫球蛋白 A（IgA）和 G（IgG）抗体产生细胞（APCs）广泛分布。我们的发现表明，骆驼的胃不仅具有消化功能，还参与了机体的部分免疫功能。
