Plant-made oral vaccines can be a cost-effective method to control infectious diseases of humans and farm animals. Pig edema is a bacterial disease caused by enterohemorrhagic Escherichia coli producing the toxin Shiga toxin 2e (Stx2e). In our previous report, we chose the non-toxic B subunit of Stx2e (Stx2eB) as a vaccine antigen, and Stx2eB was expressed in lettuce (Lactuca sativa L., cv. Green wave). We found that a double repeated Stx2eB (2×Stx2eB) accumulates to higher levels than a single Stx2eB. In this study, we analyzed progeny plants introduced with 2×Stx2eB in which the gene was expressed under the control of conventional cauliflower mosaic virus 35S RNA (CaMV 35S) promoter, and found that the lettuce underwent transgene silencing and bore few seeds. We resolved these problems by using a transgene cassette which harbored a transcriptional promoter derived from the lettuce ubiquitin gene and a longer version of HSPT. The lettuce harboring this expression construct will be valuable in establishing the seed lot system on the basis that thousands of seeds can be obtained from one plant body and the resulting progeny plants accumulate 2×Stx2eB at high levels without the transgene silencing.

Tuberculosis (TB) is globally more prevalent today than in any period in the past. Although the estimated number of deaths due to TB each year is 1.5-2 million, cutaneous TB accounts for a small percentage (< 1-2%) of all cases of TB. Cutaneous TB has a wide variety of clinical features, with increasing numbers of immunocompromised patients. Bullous pemphigoid, which was observed in the case described here, is a disease often seen in elderly people. Immunosuppressive treatment, such as systemic steroid therapy, is one of the standard treatments for bullous pemphigoid. In the present case, we considered whether systemic steroid therapy could induce cutaneous TB. Although cutaneous TB is divided into multibacillary and paucibacillary forms in the current classification, the clinical features of this case, such as cellulitis, did not fit into any forms. Moreover, although cutaneous TB is histologically characterized by epithelioid granuloma with caseous necrosis, epithelioid granuloma was not seen in this case. We draw attention here to the presence of atypical cutaneous TB that exhibits a clinical profile of cellulitis depending on the host condition. CASE REPORTAn 86-year-old man was admitted with a fever of around 39ºC and an ill-defined, tender, erythematous, warm and swelling plaque in the left thigh ( Fig. 1A). Five months earlier, he had been diagnosed with bullous pemphigoid and underwent pulse steroid therapy. One month after pulse steroid therapy for bullous pemphigoid, he developed unexplained nephritis syndrome due to crescentic glomerulonephritis and underwent pulse steroid therapy again and subsequent oral prednisolone at a dosage of 20 mg/day. Whether he had a history of TB was unclear. On admission, no respiratory symptoms were noted and an initial chest X-ray did not show any specific evidence of tuberculosis. Laboratory studies revealed an elevated white blood cell count of 8,300 IU/l, C-reactive protein of 10.0 mg/ dl, aspartate aminotransferase of 66 IU/l, alanine aminotransferase of 78 IU/l, total protein of 5.3 g/dl, albumin of 2.8 g/dl, blood urea nitrogen of 41.5 mg/dl, and creatinine of 2.15 mg/ dl. He was diagnosed with cellulitis. Despite wide-spectrum antibiotic treatments (ampicillin/sulbactam and clindamycin), no response was observed.Using subsequent investigation of histopathology, inflammatory cell infiltration, consisting mostly of neutrophils mixed with small numbers of lymphocytes, histiocytes, and eosinophils, was noted through the entire dermis and subcutis. However, no caseous necrosis or epithelioid cell granuloma was present ( Fig. 1B and C). Periodic acid-Schiff (PAS) and Grocott stains were negative. Since Weber-Christian disease was a differential diagnosis, steroid pulse therapy was performed. However, an erythematous plaque gradually enlarged. One month after admission, a chest X-ray, performed to follow up thoracic effusion associated with nephritic syndrome, revealed a large number of nodular and granular shadows in both lung fields. Since chest X-ray suggested pulmona...

The development of functional protein production systems using transgenic plants as hosts has been rapidly progressing in recent years. Lettuce (Lactuca sativa L.) has been studied as one such host, and it has been reported that the biomass of lettuce per area and target protein expression level can be increased by optimizing the cultivation conditions. Therefore, we investigated methods to minimize the input light energy per target protein to reduce production costs. Herein, we examined the yield of a nontoxic B subunit of Stx2e (Stx2eB) from transgenic lettuce under various cultivation conditions. Stx2eB acts as a vaccine against swine edema disease. The effects of photon flux densities (PPFDs), photoperiod, and light source on Stx2eB production were examined and the findings suggested that 400 μmol m−2 s−1, 24 h, and white LED lamps, respectively, contributed to energy-efficient Stx2eB production. In addition, Stx2eB was produced 1.4 times more efficiently per unit area time using a high plant density (228.5 plants m−2) than a common density (30.4 plants m−2). The findings of the present study can facilitate the development of energy-efficient and low-cost production processes for vaccine protein production, considering temporal and spatial perspectives.