Hsp70 enhances presentation of FMDV antigen to bovine CD4+ T cells in vitro

Foot-and-mouth disease virus (FMDV) is the causative agent of a highly contagious acute vesicular disease affecting cloven-hoofed animals, including cattle, sheep and pigs. The current vaccine induces a rapid humoral response, but the duration of the protective antibody response is variable, possibly associated with a variable specific CD4⁺ T cell response. We investigated the use of heat shock protein 70 (Hsp70) as a molecular chaperone to target viral antigen to the Major Histocompatibility Complex (MHC) class II pathway of antigen presenting cells and generate enhanced MHC II-restricted CD4⁺ T cell responses in cattle. Monocytes and CD4⁺ T cells from FMDV vaccinated cattle were stimulated in vitro with complexes of Hsp70 and FMDV peptide, or peptide alone. Hsp70 was found to consistently improve the presentation of a 25-mer FMDV peptide to CD4⁺ T cells, as measured by T cell proliferation. Complex formation was required for the enhanced effects and Hsp70 alone did not stimulate proliferation. This study provides further evidence that Hsp70:peptide complexes can enhance antigen-specific CD4⁺ T cell responses in vitro for an important pathogen of livestock.     

Agarose gel electrophoretic fractionation of serum proteins in adult cattle. II. A study of cows with different diseases.

In 283 dairy cows suffering from internal disorders the serum proteins were studied by agarose gel electrophoresis supplemented by total protein and albumin determinations. The clinical diagnoses could be grouped according to protein pattern. Group 1 (abomasal displacement and traumatic muscle injury) did not appreciably affect the serum protein concentrations and represented primarily non-inflammatory diseases or diseases of non-infectious origin. Group 2 (leukosis) occupied an exceptional position, with heavy lowering of albumin unaccompanied by a corresponding rise of total globulin. The γ-globulin concentration was significantly lowered. Group 3 (acute traumatic peritonitis) represented an acute inflammatory process with increase chiefly of the α-globulins, while the γ-globulin concentration was normal. Group 4 (chronic traumatic peritonitis, summer mastitis, chronic subclinical mastitis, chronic laminitis and polyarthritis, urinary tract infection, abscess, and sub-acute-chronic pneumonia) comprised diseases chiefly of chronic inflammatory character and with infectious origin. Especially characteristic was the heavy rise of globulins in general and of γ-globulin in particular. In most cases there was a large increase also of the α- and p-globulin fractions.     

Preliminary studies of serum acute-phase protein concentrations in hematologic and neoplastic diseases of the dog

Serum concentrations of acute-phase proteins (APPs): haptoglobin (Hp), ceruloplasmin (Cp), serum amyloid A (SAA), and C-reactive protein (CRP) were determined in healthy dogs (n = 15) and dogs with different diseases grouped as acute inflammation (I, n = 12), hematologic neoplasias (HT, including leukemia and lymphoma, n = 16), nonhematologic neoplasias (NHT, including epithelial, mesenchymal, and mixed, n = 20), and autoimmune hemolytic anemia (AIHA, n = 8). SAA and CRP were analyzed using commercially available enzyme-linked immunosorbent assay (ELISA) kits, and Hp and Cp were measured using colorimetric methods, all previously validated for use in dogs. Increased concentrations of all APPs were observed in all groups of diseased dogs, but statistical significance only was observed with Hp (I, P < .001; HT, P < .05), Cp (I, P < .05; AIHA, P < .01), and CRP (I, P < .001; HT, P < .001; AIHA, CRP P < .05). High variability in individual APPs within each group of diseases was found with no significant differences between leukemia and lymphoma as well as among different types of neoplasia. The AIHA group had smaller increases in Hp, SAA, and CRP but higher concentrations of Cp. When follow-up of individual cases was possible, a decrease in APPs generally was found in cases with favorable outcome. The results of this study suggest that neoplasia and hematologic diseases such as AIHA should be considered as possible causes of mild increases in APPs in dogs. Measurement of APPs may be helpful to assess clinical evolution and monitor treatment of these processes.     

Induction of immune tolerance to caseins and whey proteins by oral intubation in mouse allergy model

This study was designed to evaluate the effect of oral tolerance of caseins (CSN) and whey proteins (WP) in alleviating the allergic response to cow's milk proteins in Swiss albino mice raised on a milk protein–free diet. Oral tolerance was induced by feeding mice with 20 mg of CSN or WP once in a day for 4 days consecutively before immunization with respective protein by intraperitoneal (i.p.) injections (20 μg 200 per μl of PBS) using 2% of alum Al(OH)₃ as adjuvant. Three weeks later, oral tolerance induction was analysed in humoral and cellular compartments of CSN‐ and WP‐fed versus saline‐fed control mice groups by measuring seric and intestinal antibody responses, mRNA abundance in splenic tissue and cytokine secretion patterns. The specific serum immunoglobulin‐E (IgE) levels were significantly suppressed (p < 0.05), while sIgA was enhanced in these groups when compared with their respective saline‐fed mice. Moreover, the mRNA levels of interferon‐γ (IFN‐γ) and interleukin‐4 (IL‐4) in both CSN‐ and WP‐tolerized mice were found to be significantly decreased, while the abundance of interleukin‐10 (IL‐10) and transforming growth factor‐β (TGF‐β) was increased significantly, as compared to respective control groups. Finally, cytokine profiles indicated a reciprocal decrease in IL‐4 and IFN‐γ versus an increase in IL‐10 secretions in supernatants of cultured splenocytes of tolerized mice. Taken together, these results clearly showed that oral administration of cows' milk caseins and whey proteins can induce significant hyposensitization in mice, with the participation of suppressor cytokines.     

肠道紧密连接及调控通路研究进展

紧密连接是广泛存在于上皮细胞之间的一种黏连复合物,与黏附连接、间隙连接和桥粒共同构成上皮细胞连接复合体,在细胞旁途径发挥重要作用.作为肠屏障的重要组成部分,紧密连接不断受到外界刺激(如病原体、细胞因子、药物、缺血、缺氧等)的威胁,它们能通过影响紧密连接的定位、表达或紧密连接蛋白的磷酸化或去磷酸化,介导多个信号通路来改变...     

热应激蛋白对畜禽抗应激机理的研究进展

热应激蛋白(heat shock proteins, HSPs)是机体在应激条件下所产生的一组特异性蛋白质,能使机体迅速适应环境变化。作者简要介绍了HSPs的来源及分类,阐述了HSP70 的基因结构和调控机制,综述了HSPs抗应激功能及在畜禽应激反应中的表达,以期为从分子水平探索HSPs 抗应激机理提供参考。     

Harpin蛋白的研究进展

由植物革兰氏阴性病原菌编码产生的harpin蛋白是激发植物过敏反应的主要因子，具有显著的诱导植物抗性和促进生长发育等多种生物学效应，同时也是研究植物抗病信号传导的理想模型。基于对harpin蛋白的深入研究，国外已开发出新型、高效、安全的生物农药。本文综述了近年来harpin蛋白的研究进展。     

Muscular dystrophy in female dogs

The most common form of muscular dystrophy in dogs and humans is caused by mutations in the dystrophin gene. The dystrophin gene is located on the X chromosome, and, therefore, disease-causing mutations in dystrophin occur most often in males. Therefore, females with dystrophin deficiency or other forms of muscular dystrophy may be undiagnosed or misdiagnosed. Immunohistochemistry was used to analyze dystrophin and a number of other muscle proteins associated with muscular dystrophy in humans, including sarcoglycans and laminin alpha2, in muscle biopsy specimens from 5 female dogs with pathologic changes consistent with muscular dystrophy. The female dogs were presented with a variety of clinical signs including generalized weakness, muscle wasting, tremors, exercise intolerance, gait abnormalities, and limb deformity. Serum creatine kinase activity was variably high. One dog had no detectable dystrophin in the muscle; another was mosaic, with some fibers normal and others partly dystrophin-deficient. A 3rd dog had normal dystrophin but no detectable laminin alpha2. Two dogs could not be classified. This study demonstrates the occurrence of dystrophin- and laminin alpha2-associated muscular dystrophy and the difficulty in clinical diagnosis of these disorders in female dogs.