Mouse IgG2a [FITC]

Systemic lupus erythematosus (SLE) patients are at risk for pneumococcal infection. Twenty-one consecutive SLE patients (40[25-75] years) received the sequential PCV13/PPSV23 vaccine and factors associated with long-term protection were analyzed. Immune protection, defined by an antigen-specific IgG concentration >= 1.3 mu g/mL for at least 70% of 7 pneumococcal serotypes was assessed at baseline, 2, 6, 12 and 36 months defining long-term protection. Only 10 patients showed pneumococcal immune protection 36 months after vaccination. Eleven (52.4%) patients had no long-term protection with a seroconversion that never or only transiently occurred. SLE disease features, treatment received and immunological characteristics did not differ between protected and unprotected patients except for the pre-vaccination IgG2 serum levels. Serum IgG2 level >2.125 mu g/ml showed a sensitivity of 100% and a specificity of 90.9% for long-term protection. Sequential pneumococcal vaccination conferred poor immune protection in SLE. Baseline IgG2 serum level identified patients able to benefit from pneumococcal vaccination. (c) 2020 Elsevier Ltd. All rights reserved.

As a novel enteropathogenic coronavirus, porcine deltacoronavirus (PDCoV) warrants further investigation. In this study, a Chinese PDCoV strain, designated CHN-HN-1601, was isolated from the faeces of a diarrhoeic piglet. After plaque purification, the genome was determined which shared 97.5%-99.5% nucleotide identities with 71 representative PDCoV strains available in the GenBank. The pathogenic properties of CHN-HN-1601 were evaluated using 5-day-old piglets. All inoculated piglets developed severe diarrhoea from 2 days post-infection (dpi) onwards. To our surprise, two periods of diarrhoea starting from 2 to 7 dpi and from 13 to 19 dpi were observed in affected piglets during the experiment. Faecal viral shedding of the inoculated piglets was detected by real-time RT-PCR, with viral shedding peaked at 4 and 16 dpi, respectively. At necropsy at 5 dpi, the main gross lesions included transparent, thin-walled and gas-distended intestines containing yellow watery contents. Further histopathological examinations, including haematoxylin and eosin staining, immunohistochemistry and RNAscope in situ hybridization, revealed that the virus infection caused severe villous atrophy of the small intestines, with PDCoV antigen and RNA mainly distributed in the cytoplasm of the villous epithelial cells of jejunum and ileum in piglets. The dynamic production of PDCoV-specific IgG and neutralizing antibodies in serum of the affected piglets was also assessed using a whole virus-based ELISA and an immunofluorescence assay-based neutralization test, respectively. Furthermore, a full-length cDNA infectious clone of CHN-HN-1601 was constructed using a bacterial artificial chromosome system. The rescued virus exhibited in vitro growth and pathogenic properties similar to the parental virus. Taken together, our study not only enriches the information of PDCoV, but also provides a useful reverse genetics platform for further pathogenesis exploration of the virus.