Spleen deposition of Cryptococcus neoformans capsular glucuronoxylomannan in rodents occurs in red pulp macrophages and not marginal zone macrophages expressing the C-type lectin SIGN-R1
Spleen deposition of Cryptococcus neoformans capsular glucuronoxylomannan in rodents occurs in red pulp macrophages and not marginal zone macrophages expressing the C-type lectin SIGN-R1
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DOI：
10.1080/13693780701747182
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发表时间：
2008-01-01
期刊：
影响因子：
2.9
通讯作者：
Casadevall, Arturo
中科院分区：
文献类型：
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作者：
De Jesus, Magdia;Park, Chae Gyu;Casadevall, Arturo
微生物多糖在宿主组织中的命运是一个重要的考虑因素，因为这些化合物通常是免疫调节剂。表达C型凝集素受体SIGN-R1的脾边缘区巨噬细胞摄取中性多糖，如葡聚糖和肺炎链球菌的荚膜多糖。鉴于新生隐球菌荚膜多糖的主要成分葡萄糖醛酸甘露聚糖（GXM）在静脉注射时定位于脾脏，我们研究了GXM摄取是否由表达SIGN-R1受体的小鼠脾脏巨噬细胞介导。当与对照相比时，在用SIGN-R1阻断抗体处理的小鼠的脾脏中未检测到GXM沉积的量和位置的显著差异。类似地，Dectin-1（SIGN-R1的共受体）的阻断抗体对脾脏内的GXM分布没有影响。注射FITC-葡聚糖和GXM的小鼠和大鼠脾脏的组织学检查显示无显著共定位，葡聚糖和GXM分别在边缘和红髓巨噬细胞中发现。因此，我们得出结论，GXM不是沉积在边缘区巨噬细胞。然而，GXM沉积在红髓中。这些结果表明，这些多糖有一个选择性定位到不同的受体，如SIGN-R1的FITC葡聚糖在边缘区和一个待确定的受体选择性表达的红髓巨噬细胞GXM。
The fate of microbial polysaccharides in host tissues is an important consideration because these compounds are often immune modulators. Splenic marginal zone macrophages that express the C-type lectin receptor SIGN-R1, take up neutral polysaccharides such as dextran and the capsular polysaccharide of Streptococcus pneumoniae. Given that the major component of Cryptococcus neoformans capsular polysaccharide, glucuronoxylomannan (GXM), localizes in the spleen when injected intravenously, we investigated whether GXM uptake was mediated by splenic macrophages expressing the SIGN-R1 receptor in mice. No significant differences in the amount and location of GXM deposition were detected in the spleens of mice treated with a SIGN-R1 blocking antibody when compared to controls. Similarly, a blocking antibody to Dectin-1, a co-receptor of -SIGN-R1, had no effects on GXM distribution within the spleen. Histological examination of spleens from mice and rats injected with FITC-Dextran and GXM revealed no significant co-localization, with Dextran and GXM being found in marginal and red pulp macrophages, respectively. Hence we conclude that GXM was not deposited in marginal zone macrophages. However, GXM deposition was found in the red pulp. These results indicate that there is a selective localization of these polysaccharides to different receptors such as SIGN-R1 for FITC dextran in marginal zone and a to-be-identified receptor selectively expressed by red pulp macrophages for GXM.