Identification of heat shock protein 60 as the ligand on Histoplasma capsulatum that mediates binding to CD18 receptors on human macrophages
Identification of heat shock protein 60 as the ligand on Histoplasma capsulatum that mediates binding to CD18 receptors on human macrophages
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DOI：
10.4049/jimmunol.170.1.487
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发表时间：
2003-01-01
影响因子：
4.4
通讯作者：
Newman, SL
中科院分区：
文献类型：
--
作者：
Long, KH;Gomez, FJ;Newman, SL
荚膜组织胞浆菌 (Hc) 是一种兼性细胞内真菌，可与巨噬细胞 (Mphi) 上的 CD11/CD18 受体结合。为了鉴定 Hc 酵母上 Mphi 识别的配体，使用纯化的人补体受体 3 型（CR3、CD11b/CD18）来探测 Hc 细胞壁和细胞膜去污剂提取物的 Far Western 印迹。 CR3 识别单个 60 kDa 蛋白，该蛋白被鉴定为热休克蛋白 60 (hsp60)。对活酵母进行生物素化，然后用链霉亲和素包被的珠子进行沉淀，并用抗 hsp60 进行蛋白质印迹，证明 hsp60 位于 Hc 酵母的表面。电子和共聚焦显微镜显示 hsp60 以离散的簇形式驻留在酵母细胞壁上。重组 hsp60 (rhsp60) 抑制 Hc 酵母与 Mphi 的附着。重组 hsp60 以及针对 CD11b 和 CD18 的抗体抑制酵母与转染 CR3 (CHO3) 的中国仓鼠卵巢细胞的结合。涂有 rhsp60 的聚苯乙烯珠与 Mphi 结合，并且 CD11 和 CD18 的附着被 Ab 抑制。冷冻/解冻提取物 (F/TE) 是一种含有 hsp60 的 He 酵母表面蛋白制剂，可抑制 Hc 酵母与 Mphi 的附着。 F/TE 中 hsp60 的耗尽消除了 F/TE 阻断 Hc 与 Mphi 结合的能力。有趣的是，rhsp60 不会抑制 Hc 酵母与树突状细胞 (DC) 的结合，树突状细胞通过非常晚的 Ag 5 识别 Hc。此外，即使 hsp60 耗尽，F/TE 也会抑制 Hc 与 DC 的附着。因此，Hc hsp60 似乎是介导 Hc 与 Mphi CD11/CD18 附着的主要配体，而 DC 通过不同的配体识别 Hc。
Histoplasma capsulatum (Hc), is a facultative intracellular fungus that binds to CD11/CD18 receptors on macrophages (Mphi), To identify the ligand(s) on Hc yeasts that is recognized by Mphi, purified human complement receptor type 3 (CR3, CD11b/CD18) was used to probe a Far Western blot of a detergent extract of Hc cell wall and cell membrane. CR3 recognized a single 60-kDa protein, which was identified as heat shock protein 60 (hsp60). Biotinylation of viable yeasts, followed by precipitation with streptavidin-coated beads, and Western blotting with anti-hsp60 demonstrated that hsp60 was on the surface of Hc yeasts. Electron and confocal microscopy revealed that hsp60 resided on the yeast cell wall in discrete clusters. Recombinant hsp60 (rhsp60) inhibited attachment of Hc yeasts to Mphi. Recombinant hsp60 and Abs to CD11b and CD18 inhibited binding of yeasts to Chinese hamster ovary cells transfected with CR3 (CHO3). Polystyrene beads coated with rhsp60 bound to Mphi, and attachment was inhibited by Abs to CD11 and CD18. Freeze/thaw extract (F/TE), a preparation of He yeast surface proteins that contained hsp60, inhibited the attachment of Hc yeasts to Mphi. Depletion of hsp60 from F/TE removed the capacity of F/TE to block binding of Hc to Mphi. Interestingly, rhsp60 did not inhibit binding of Hc yeasts to dendritic cells (DC), which recognize Hc via very late Ag 5. Moreover, F/TE inhibited attachment of Hc to DC even when depleted of hsp60. Thus, Hc hsp60 appears to be a major ligand that mediates attachment of Hc to Mphi CD11/CD18, whereas DC recognize Hc via a different ligand(s).