Toyoshima M, Chida K, Sato A
Department of Internal Medicine, Hamamatsu University School of Medicine, Japan.
Respirology. 2000 Jun;5(2):141-5. doi: 10.1046/j.1440-1843.2000.00241.x.
Bronchus-associated lymphoid tissue (BALT) plays an important role in the immunological defence of airways. However, the mechanisms of BALT development, antigen sampling, and subsequent cell kinetics remain unclear. To clarify these chronological processes, we used a Pseudomonas aeruginosa-exposed mouse model.
In BALB/c and C57BL/6 mice, BALT development was induced by inhalation of heat-killed P. aeruginosa after sensitization with subcutaneous injection of P. aeruginosa in the presence of Freund's complete adjuvant. Subsequently, we chronologically killed these mice who had inhaled PKH26-labelled P. aeruginosa and examined bacterial transport using fluorescence microscopy. The distribution of interleukin-4-positive cells and interferon-gamma-positive cells was studied immunohistochemically.
The degree of BALT hyperplasia was greater in sensitized mice than in non-sensitized mice and in BALB/c mice than in C57BL/6 mice. PKH26-labelled bacteria were found in BALT earlier in sensitized mice than in non-sensitized mice. Immunohistochemical studies revealed that interleukin-4-positive cells predominated over interferon-gamma-positive cells in the peripheral areas of lymphoid follicles.
These results indicate that administered antigens are actively transported into BALT and that sensitized Th2 lymphocytes play an important role in forming and maintaining BALT.
支气管相关淋巴组织（BALT）在气道免疫防御中发挥重要作用。然而，BALT发育、抗原摄取及后续细胞动力学机制仍不清楚。为阐明这些按时间顺序发生的过程，我们使用了铜绿假单胞菌感染的小鼠模型。
在BALB/c和C57BL/6小鼠中，在弗氏完全佐剂存在的情况下，通过皮下注射铜绿假单胞菌致敏后，吸入热灭活的铜绿假单胞菌诱导BALT发育。随后，我们按时间顺序处死吸入PKH26标记的铜绿假单胞菌的小鼠，并使用荧光显微镜检查细菌转运情况。通过免疫组织化学研究白细胞介素-4阳性细胞和干扰素-γ阳性细胞的分布。
致敏小鼠的BALT增生程度高于未致敏小鼠，且BALB/c小鼠高于C57BL/6小鼠。在致敏小鼠中，PKH26标记的细菌比未致敏小鼠更早出现在BALT中。免疫组织化学研究显示，在淋巴滤泡周边区域，白细胞介素-4阳性细胞多于干扰素-γ阳性细胞。
这些结果表明，给予的抗原被主动转运至BALT中，且致敏的Th2淋巴细胞在BALT的形成和维持中起重要作用。
