Veterinary Research Institute, Hudcova 70, 621 00, Brno, Czech Republic.
Veterinary Faculty, Department for Veterinary Sciences, Ludwig Maximilians University Munich, Planegg, Germany.
Sci Rep. 2024 Oct 25;14(1):25410. doi: 10.1038/s41598-024-76856-2.
The chicken caecum is colonised by hundreds of different bacterial species. Which of these are targeted by immunoglobulins and how immunoglobulin expression shapes chicken caecal microbiota has been addressed in this study. Using cell sorting followed by sequencing of V3/V4 variable region of 16S rRNA, bacterial species with increased or decreased immunoglobulin coating were determined. Next, we determined also caecal microbiota composition in immunoglobulin knockout chickens. We found that immunoglobulin coating was common and major taxa were coated with immunoglobulins. Similarly, more taxa required immunoglobulin production for caecum colonisation compared to those which became abundant in immunoglobulin-deficient chickens. Taxa with low immunoglobulin coating such as Lactobacillus, Blautia, [Eubacterium] hallii, Megamonas, Fusobacterium and Desulfovibrio all encode S-layer proteins which may reduce interactions with immunoglobulins. Although there were taxa which overgrew in Ig-deficient chickens (e.g. Akkermansia) indicating immunoglobulin production acted to exclude them from the chicken caecum, in most of the cases, immunoglobulin production more likely contributed to fixing the desired microbiota in the chicken caecum.
鸡盲肠中定植着数百种不同的细菌物种。本研究旨在探讨这些细菌中哪些是免疫球蛋白的靶标，以及免疫球蛋白的表达如何影响鸡盲肠微生物群。本研究通过细胞分选，然后对 16S rRNA 的 V3/V4 可变区进行测序，确定了免疫球蛋白包被增加或减少的细菌种类。接下来，我们还确定了免疫球蛋白敲除鸡的盲肠微生物群组成。结果发现，免疫球蛋白包被很常见，主要的细菌类群都被免疫球蛋白包被。同样，与在缺乏免疫球蛋白的鸡中大量存在的细菌相比，需要产生免疫球蛋白才能定植盲肠的细菌类群更多。免疫球蛋白包被较少的细菌，如乳酸杆菌、布劳特氏菌、[真杆菌属] hallii、巨单胞菌、梭菌和脱硫弧菌，都编码 S-层蛋白，这可能会减少与免疫球蛋白的相互作用。尽管有一些在 Ig 缺陷鸡中过度生长的细菌（如阿克曼氏菌）表明免疫球蛋白的产生将它们从鸡盲肠中排斥，但在大多数情况下，免疫球蛋白的产生更可能有助于将所需的微生物群固定在鸡盲肠中。
