微生物殖民影响了肠道内膜自身的早期B系发展
Duane R Wesemann1, Andrew J Portuguese, Robin M Meyers
1Program in Cellular and Molecular Medicine and Department of Medicine, Children's Hospital Boston, Boston, Massachusetts 02115, USA. dwesemann@research.bwh.harvard.edu
Nature
|August 23, 2013
概括
B细胞的发育发生在小鼠的肠膜内,而不仅仅是骨髓. 这种与肠道相关的B细胞发育,涉及V(D) J重组和受体编辑,受到肠道微生物的影响,并形成抗体谱.
科学领域:
- 免疫学 免疫学 免疫学
- 发育生物学 发展生物学
- 微生物组研究 微生物组研究
背景情况:
- RAG1/RAG2内核酶 (RAG) 对于V(D) J重组至关重要,它组装免疫球蛋白基因以产生抗体多样性.
- 主要的B细胞发育和免疫球蛋白谱的多样化主要发生在骨髓中.
- 在不成熟的B细胞中进行受体编辑,涉及持续的RAG表达,在对抗原遭遇的反应中改进抗体特异性.
研究的目的:
- 调查早期B细胞发育是否发生在外骨部位,特别是小鼠肠道内膜 (LP).
- 为了确定V(D) J重组和受体编辑过程是否能调节LP中的免疫球蛋白谱.
- 探索开始性微生物对肠关联B细胞发育和免疫球蛋白库的影响.
主要方法:
- 在断奶年龄的小鼠肠膜自身 (LP) 中分析B系细胞.
- 在LP B系细胞中检测RAG表达和V(D) J重组中间体.
- 在LP和骨髓B系细胞之间比较VH和Vκ谱.
- 在与肠道微生物群结合的无菌小鼠中评估B细胞发育和免疫球蛋白表达 (Igκ与Igλ).
主要成果:
- 在小鼠LP中鉴定出具有pro-B,pre-B和编辑表型的RAG表达B系细胞.
- LP B系细胞表现出正在进行的V(D) J重组和受体编辑,与骨髓对应物不同.
- 与骨髓细胞相比,LP B系细胞显示了类似的VH谱,但与骨髓细胞相比显著不同的Vκ谱.
- 无菌小鼠的殖民导致Igλ增加到Igκ表达B细胞比率,特别是在LP.
结论:
- 早期的B细胞发育发生在肠道粘膜内,特别是自身膜.
- V(D) J重组和LP中的受体编辑调节了肠道的初级免疫球蛋白谱.
- 来自共生微生物的细胞外信号调节了与肠道相关的B细胞发育,并影响了免疫球蛋白谱.
相关概念视频
Development of Human Microbiota
The human microbiota begins developing at birth and undergoes continual change as we age. Infancy marks a critical period of microbial sensitivity, offering a “window of opportunity” during which beneficial microbes help mature the immune system. By age three, children typically develop a more stable and diverse microbial community. Newborns acquire microbes from their immediate environment; vaginal delivery favors maternal vaginal microbes, while cesarean births favor microbes from the skin...
Development of the Oral Microbiota
The establishment of the oral microbiome begins before birth, challenging the long-held belief that the fetal oral cavity is sterile. The presence of oral microbes such as Streptococcus and Fusobacterium in amniotic fluid suggests that microbial exposure may occur in utero, potentially through translocation from the maternal oral or gastrointestinal tract. This early colonization primes the neonatal immune system and sets the stage for subsequent microbial succession. Maternal health,...
Introduction to the Human Microbiota
Microorganisms colonize various regions of the human body, including the mouth, nasal passages, throat, stomach, intestines, urogenital tract, and skin. The total number of microbial cells is estimated to range from 10¹³ to 10¹⁴—comparable to, or exceeding, the number of human somatic cells. This host–microbiome relationship has led to the conceptualization of humans as supraorganisms, wherein microbial communities perform vital roles in development, immunity, and disease...
Microbiota of the Stomach and Small Intestine
The human gastrointestinal (GI) tract is characterized by distinct physicochemical conditions that shape its microbial communities. Among these, the stomach presents a particularly challenging environment for microbial colonization due to its highly acidic pH, ranging from 1 to 3. This extreme acidity effectively limits microbial density. However, certain acid-tolerant microorganisms are capable of surviving in this niche. Notably, Helicobacter pylori can colonize the gastric mucosa,...
Anatomy of the Intestines
Although digestion of proteins, carbohydrates, and lipids may begin in the stomach, it is completed in the intestine. The absorption of nutrients, water, and electrolytes from food and drink also occurs in the intestine. The intestines can be divided into two structurally distinct organs—the small and large intestines.
Small Intestines
The small intestine is an ~7 meter-long tube with an inner diameter of just 2.5 cm. Since most nutrients are absorbed here, the inner lining of the small...
Small Intestines
The small intestine is an ~7 meter-long tube with an inner diameter of just 2.5 cm. Since most nutrients are absorbed here, the inner lining of the small...
Microbiota of the Large Intestine
The large intestine hosts the most densely populated microbial ecosystem in the human body. This complex community primarily consists of anaerobic bacteria, with Bacillota (formerly Firmicutes) and Bacteroidota (formerly Bacteroidetes) as the predominant groups. The distribution of these microbes varies along different sections of the large intestine, influenced by local environmental factors such as oxygen availability and nutrient composition.The cecum, located at the beginning of the large...


