Characterization of leukocyte functions from cattle with leukocyte adhesion deficiency (BLAD) and prevalence of BLAD-carrier in Holstein cattle in Japan

我们进行了上述研究，结果总结如下：x线检查显示BLAD小母牛由于白细胞功能障碍导致严重的骨吸收、骨溶解和严重的进行性下颌下牙周炎。使用抗cd18抗体对blad小母牛淋巴结进行免疫组化分析，未发现cd18阳性细胞。通过对对照和BLAD母牛血液单核吞噬细胞Fc受体表达、细胞质Ca^<2+>信号、化学发光（CL）反应、电子自旋共振（ESR）结合自旋捕获的研究，探讨补体受体3型（CR3）与Fc受体表达及其功能反应的关系。受聚集IgG （Agg-IgG）的刺激，单核吞噬细胞上的Fc受体增强，胞质Ca^<2+>信号转导、CL反应和esr -自旋捕获等与Fc受体增强有关。测定对照和cd18缺陷牛中性粒细胞在预涂有ⅰ型胶原、ⅳ型胶原、纤维连接蛋白和层粘连蛋白的培养板上的粘附性，以评估细胞外基质粘附的可能因素。cd18缺失的中性粒细胞对ⅰ型胶原、ⅳ型胶原和纤维连接蛋白的粘附活性显著降低；然而，在cd18缺陷中性粒细胞和对照中性粒细胞中观察到与层粘连蛋白相似的粘附。测定了牛白细胞中CD11/CD18的生物合成、细胞内Ca^<2+>信号、CL反应和中性粒细胞的膜流动性。CD11/CD18复合物的合成在正常母牛的白细胞中被清楚地检测到，但在blad母牛中没有。在受OPZ、Agg-IgG刺激的blad母牛中性粒细胞中，可以明显检测到Ca^<2+>的短暂期增加，而与对照组相比，持续期缺乏或显著减少。来自对照组和blad牛的中性粒细胞在膜流动性方面没有发现差异。采用DNA-PCR方法对日本6个地区20个畜群的796头荷斯坦奶牛的血液样本进行了无BLAD、携带BLAD和受BLAD影响的检测，BLAD携带率为0 ~ 23.5%，平均为8.1%（70/796）。大约35%的奶牛群的brad携带者患病率超过10%。据估计，日本荷斯坦奶牛出生时BLAD的发生率为0.16%。在日本，一项根除荷斯坦牛BLAD中编码受损CD18基因的计划正在缓慢实施。这些结果表明，BLAD的病理生理变化与BLAD白细胞CD18表达不足密切相关。本研究为日本荷斯坦牛BLAD的防治提供了有价值的信息。少

The above-entitled study was performed and the results were summarized as follows :Severe bone resorption, osteolysis and severe progressive periodontitis in submandibula due to dysfunction of leukocytes in heifers with BLAD were demonstrated by radiographic examination. Immunohistochemical analysis of lymph nodes using anti-CD18 antibody demonstrated that CD18-positive cells were not found on those from the BLAD-heifer.Fc receptor expression, cytoplasmic Ca^<2+> signaling, chemiluminescent (CL) response, and electron spin resonance (ESR) combined with spin trapping of blood mononuclear phagocytes from control heifers and a heifer with BLAD were evaluated to elucidate the relationships between complement receptor type 3 (CR3) and Fc receptor expression and their functional responses. Fc receptors on mononuclear phagocytes from the heifer with BLAD were enhanced, and their cytoplasmic Ca^<2+> singnaling, CL responses, and ESR-spin trapping when stimulated with aggregated IgG (Agg-IgG) o … More psonized zymosan (OPZ) appeared to be associated with enhanced Fc receptors.The adhesiveness of control and CD18-deficient bovine neutrophils on culture plates precoated with collagen I,collagen IV,fibronectin and laminin was measured to evaluate the possible factors for adherence to extracellular matrices. The adhesiveness activities of CD18-deficient neutrophils to collagen I,collagen IV and fibronectin were significantly diminished ; however, similar adhesion to laminin was observed in CD18-deficient neutrophils and control neutrophils.Biosynthesis of CD11/CD18 in bovine leukocytes, intracellular Ca^<2+> signaling, CL responses and membrane fluidity of neutrophils from control heifers and a BLAD-heifer were measured. The synthesis of CD11/CD18 complex was clearly detected in leukocytes from a normal heifer, but not in a BLAD-heifer. The ttransient phase of increased Ca^<2+> was clearly detected in neutrophils from a BLAD-heifer stimulated with OPZ,Agg-IgG,whereas the sustained phase was deficient or significantly decreased compared with controls. No differences in membrane fluidity were detected between neutrophils derived from control and BLAD-cattle.Blood samples from 796 Holstein dairy cows in 20 herds from 6 districts in Japan were examined to determine whether they were BLAD-free, BLAD carriers, or BLAD-affected by use of DNA-PCR analysis, BLAD-carrier rates ranged from 0 to 23.5% and the mean BLAD-carrier rate was 8.1% (70/796). Approximately 35% of the dairy herds had a prevalence of more than 10% of BLAD-carriers. The rate of the occurrence of BLAD in Japanese Holstein dairy cattle was estimated to be 0.16% at birth. A program for the eradication of the gene encoding impaired CD18 for BLAD in Holstein cattle is slowly being enacted in Japan.These results demonstrate that pathophysiological changes of BLAD are closely associated with the deficiency of CD18 expression on BLAD-leukocytes. This study provide a valuable information for the control of BLAD in Japanese Holstein cattle. Less