Immunological detection of a cysteine protease in the skin and other tissues

Summary Monospecific antibody directed to cysteine protease of 2-day-old rat epidermis recently characterized as being different from the proteases previously reported was produced in rabbits. By immunofluorescence microscopy and immunoperoxidase staining with an avidin-biotin-peroxidase method the protease was found to be present in the epidermis of rodents of different ages as well as that of humans, but not in the dermis. The staining in germinative cells was more intense than in cells in the superficial layers. It appeared as irregular patches in the nuclei and stained more diffusely in the cytoplasm where small granular components, strongly stained, were identified. The staining patterns in granular cells showed accumulation of the antigen in a granular form. The morphology and distribution of granules resembled those of keratohyalin-like granules in the nucleus and dense homogenous deposits in the cytoplasm. In cornified cells the reaction product was localized by the plasma membrane where concentration of the dense homogenous deposits occurred, suggesting that the cysteine protease is one component of the unique and characteristic structure of differentiated keratinocytes. In addition, the cysteine protease antigen having the same molecular weight as the epidermal enzyme was detected in liver, kidney and lung indicating a wider tissue distribution of the protease. The significance of the protease in regulation of cellular functions remains to be investigated.     

Analysis of sheep T-cell receptor β-chain heterogeneity

 We analyzed nucleotide and deduced amino acid sequence heterogeneity of sheep T-cell receptor β-chain cDNAs isolated from an anchored-polymerase chain reaction library. Evaluation of 34 individual rearrangements has defined 18 new β-chain variable region sequences which have been clustered into 13 families. Presumptive allelic polymorphisms of four of these variable regions have been defined, as well as ten distinct β-chain joining region sequences. The present analysis indicates that sheep T-cell receptor β-chains are composed of characteristic leader, variable, joining, and constant region sequences, and that imprecise joining and N-region addition contribute significantly to diversity in the third hypervariable region. Thus, it appears that sheep, like all other mammals studied to date, employ somatic rearrangement of multiple germline genes to create β-chain heterogeneity. These findings have allowed us to estimate the diversity of the sheep T-cell receptor β-chain variable region repertoire, and they provide information that will permit the evaluation of the role that specific T-cell populations play in naturally occurring and experimental diseases of sheep. Received: 20 October 1997 / Revised: 20 April 1998     

Structure and Function of the Peanut Panallergen Ara h 8

The incidence of peanut allergy continues to rise in the United States and Europe. Whereas exposure to the major allergens Ara h 1, 2, 3, and 6 can cause fatal anaphylaxis, exposure to the minor allergens usually does not. Ara h 8 is a minor allergen. Importantly, it is the minor food allergens that are thought to be responsible for oral allergy syndrome (OAS), in which sensitization to airborne allergens causes a Type 2 allergic reaction to ingested foods. Furthermore, it is believed that similar protein structure rather than a similar linear sequence is the cause of OAS. Bet v 1 from birch pollen is a common sensitizing agent, and OAS results when patients consume certain fruits, vegetables, tree nuts, and peanuts. Here, we report the three-dimensional structure of Ara h 8, a Bet v 1 homolog. The overall fold is very similar to that of Bet v 1, Api g 1 (celery), Gly m 4 (soy), and Pru av 1 (cherry). Ara h 8 binds the isoflavones quercetin and apigenin as well as resveratrol avidly.     

Synthesis and evaluation of immunostimulant plasmalogen lysophosphatidylethanolamine and analogues for natural killer T cells

Plasmalogen lysophosphatidylethanolamine (pLPE) had been identified as a self antigen for natural killer T cells (NKT cells). It is very important in the development, maturation and activation of NKT cells in thymus. Besides, pLPE is a novel type of antigen for NKT cells. To evaluate the structure–activity relationship (SAR) of this new antigen, pLPE and its analogues referred to different aliphatic chains and linkages at the sn-1 position of the glycerol backbone were synthesized, and the biological activities of these analogues was characterized. It is discovered that the linkages between phosphate and lipid moiety are not important for the antigens’ activities. The pLPE analogues 1, 3, 4, 7 and 9, which have additional double bonds on lipid parts, were identified as new NKT agonists. Moreover, the analogues 4, 7 and 9 were discovered as potent Th2 activators for NKT cells.     

超声波均质化对仙台病毒ELISA测试中抗原稳定性的影响

目的研究超声波均质化（homogenization）处理对于仙台病毒在ELISA测试中抗原稳定性的影响。方法对BHK-21细胞内扩增培养的仙台病毒通过差速离心,富集后使用超声波做均质化处理,和未处理的病毒分别包被酶标板,使用标准免疫小鼠血清和SPF小鼠血清对包被平板进行测试,比较样品测试孔间测量数据的变异率。结果对免疫血清做梯度稀释,各梯度样品在未经超声处理仙台病毒抗原包被ELISA检测中测量值的变异率在1.97%～6.02%之间;在经超声处理仙台病毒抗原包被ELISA检测中测量值的变异率在0.53%～2.26%之间;SPF血清测量值的变异率均高于免疫血清;所有样品在经超声处理的病毒抗原包被ELISA检测中测量值的变异率均较小。结论超声波处理有效的提高了仙台病毒抗原的均质性,在ELISA测试中提高了抗原的稳定性。