Pathobiology of bovine leukocyte adhesion deficiency in Holstein cattle and its DNA-diagnosis.

本文对荷斯坦牛白细胞粘附缺陷症（BLAD）进行了研究，结果如下：1.中性粒细胞功能分析：患牛的中性粒细胞具有粘附、趋化、吞噬、鲁米诺依赖性荧光反应和O_2产生等功能缺陷。通过流式细胞术清楚地检测到中性粒细胞上的CD 18表达缺陷。体外白细胞功能异常与CD 18受损有关。2.单个核细胞分析：在BLAD牛的单个核细胞上清楚地检测到CD 18表达缺陷。有没有显着差异的群体中的PNA阳性，SIg轴承淋巴细胞和淋巴细胞胚细胞从控制和牛与BLAD。3.分析中性粒细胞从骨髓的有核细胞的数量是2.9至8.8倍高，骨髓的髓细胞与红细胞的比例从2.4至12牛与BLAD的范围。BLAD牛骨髓中性粒细胞趋化运动和吞噬功能严重受损。4.采用DNA-PCR方法对BLAD病牛和260头荷斯坦奶牛的白细胞进行BLAD纯合子和杂合子的检测。平均10%（26/260）的荷斯坦奶牛为BLAD携带者，年龄分布在2 ~ 10岁之间，表明BLAD的特征与白细胞表面CD 18表达受损密切相关，BLAD携带基因在荷斯坦奶牛群体中分布广泛。本研究为荷斯坦牛BLAD的防治提供了有价值的信息。

Studies on bovine leukocyte adhesion deficiency (BLAD) in Holstein cattle were performed and results were summarized as follows :1.Analysis of neutrophil function-Neutrophils from affected cattle had function defect, characterized by severely decreased adherence, chemotactic movements, phagocytosis, luminol-dependent chemiluminescent response, and O_2-producing activities. Deficient CD18 expression on neutrophils was clearly detected by flow cytometry. In vitro leukocyte functional abnormalities were associated with impaired CD18.2.Analysis of mononuclear cells-Deficient CD18 expression on mononuclear cells from cattle with BLAD was clearly detected. There were no significant differences in the population of PNA-positive, SIg-bearing lymphocytes and lymphocyte blastogenesis from control and cattle with BLAD.3.Analysis of neutrophils from bone marrow-The number of nucleated cells was 2.9 to 8.8 times higher and the myeloid to erythroid ratio of bone marrow from cattle with BLAD ranged from 2.4 to 12. Activities of chemotactic movements and phagocytosis of neutrophils isolated from bone marrow of cattle with BLAD were documented to be severely impaired.4.DNA-PCR analysis-DNA-PCR method for homolzygous and heterolozygous BLAD was applied to leukocytes from BLAD-affected cattle and 260 Holstein dairy cattle. Mean 10% (26/260) of Holstein dairy cows was proved to be BLAD-carrier, and age was ranged from 2 to 10 years old.These results demonstrate that characteristic of BLAD is closely associated with impaired CD18 expression on leukocytes, and the gene of BLAD-carrier is widely distributed in Holstein populations. This study provide a valuable information for the control of BLAD in Holstein cattle.