Hartshorn K L, Sastry K N, Chang D, White M R, Crouch E C
Departments of Medicine and Pathology, Boston University School of Medicine, Boston, Massachusetts 02118, USA.
Am J Physiol Lung Cell Mol Physiol. 2000 Jan;278(1):L90-8. doi: 10.1152/ajplung.2000.278.1.L90.
We previously demonstrated that bovine serum conglutinin has markedly greater ability to inhibit influenza A virus (IAV) infectivity than other collectins. We now show that recombinant conglutinin and a chimeric protein containing the NH(2) terminus and collagen domain of rat pulmonary surfactant protein D (rSP-D) fused to the neck region and carbohydrate recognition domain (CRD) of conglutinin (termed SP-D/Cong(neck+CRD)) have markedly greater ability to inhibit infectivity of IAV than wild-type recombinant rSP-D, confirming that the potent IAV-neutralizing activity of conglutinin resides in its neck region and CRD. Furthermore, by virtue of incorporation of the NH(2) terminus and collagen domain of SP-D, SP-D/Cong(neck+CRD) caused substantially greater aggregation of IAV particles and enhancement of neutrophil binding of, and H(2)O(2) responses to, IAV than recombinant conglutinin or recombinant rSP-D. Hence, SP-D/Cong(neck+CRD) combined favorable antiviral and opsonic properties of conglutinin and SP-D. This study demonstrates an association of specific structural domains of SP-D and conglutinin with specific functional properties and illustrates that antimicrobial activities of wild-type collectins can be enhanced through recombinant strategies.
我们之前证明，牛血清胶固素比其他凝集素具有更强的抑制甲型流感病毒（IAV）感染性的能力。我们现在表明，重组胶固素以及一种嵌合蛋白，该嵌合蛋白包含大鼠肺表面活性物质蛋白D（rSP-D）的NH₂末端和胶原结构域，并与胶固素的颈部区域和碳水化合物识别结构域（CRD）融合（称为SP-D/Cong(neck+CRD)），其抑制IAV感染性的能力比野生型重组rSP-D明显更强，这证实了胶固素强大的IAV中和活性存在于其颈部区域和CRD中。此外，由于并入了SP-D的NH₂末端和胶原结构域，SP-D/Cong(neck+CRD)比重组胶固素或重组rSP-D能引起IAV颗粒更大程度的聚集，并增强中性粒细胞对IAV的结合以及对IAV的H₂O₂反应。因此，SP-D/Cong(neck+CRD)兼具了胶固素和SP-D良好的抗病毒和调理特性。本研究证明了SP-D和胶固素的特定结构域与特定功能特性之间的关联，并表明通过重组策略可以增强野生型凝集素的抗菌活性。
