Corrigendum: Signal Transducer and Activator of Transcription 3 Hyperactivation Associates With Follicular Helper T Cell Differentiation and Disease Activity in Rheumatoid Arthritis.

[This corrects the article DOI: 10.3389/fimmu.2018.01226.].

Signal Transducer and Activator of Transcription 3 Hyperactivation Associates With Follicular Helper T Cell Differentiation and Disease Activity in Rheumatoid Arthritis.

Follicular helper T (Tfh) cells are the specialized CD4+ T cell subset that supports B cells to produce high-affinity antibodies and generate humoral memory. Not only is the function of Tfh cells instrumental to mount protect antibodies but also to support autoantibody production and promote systemic inflammation in autoimmune diseases. However, it remains unclear how the activation of Tfh cells is driven in autoimmune diseases. Here, we report that in patients with rheumatoid arthritis (RA), excessive generation of CXCR5+PD-1+ memory Tfh cells was observed and the frequency of memory Tfh cells correlated with disease activity score calculator for RA (DAS28). The differentiation of Tfh cells is dependent on signal transducer and activator of transcription 3 (STAT3), the key transcription factor downstream of cytokine signal pathways. A drastic increase of phosphorylated STAT3 (pSTAT3) in CD4+ T cells were detected in RA patients who also produced larger amounts of STAT3-stimulating cytokines, including IL-6, IL-21, IL-10, and leptin than those of healthy controls. Importantly, the phosphorylation status of STAT3 in CD4+ T cells positively correlated with the plasma concentration of IL-6 and the frequency of memory Tfh cells. This study reveals an IL-6-pSTAT3-Tfh immunoregulatory axis in the pathogenesis of RA and reinforces its candidature as biomarkers and targets for diagnosis and therapy.

Comparative analyses of phenotypic methods and 16S rRNA, khe, rpoB genes sequencing for identification of clinical isolates of Klebsiella pneumoniae.

The present work aimed to evaluate 16S rRNA, khe and rpoB gene sequencing for the identification of Klebsiella pneumoniae in comparison with phenotypic methods. Fifteen clinical isolates were examined, which were initially identified as K. pneumoniae subsp. pneumoniae using the automated VITEK 32 system in two hospitals in Enshi City, China. Their identity was further supported by conventional phenotypic methods on the basis of morphological and biochemical characteristics. Using Bayesian phylogenetic analyses and haplotypes network reconstruction, 13 isolates were identified as K. pneumoniae, whereas the other two isolates (K19, K24) were classified as Shigella sp. and Enterobacter sp., respectively. Of the three genes, 16S rRNA and khe gene could discriminate the clinical isolates at the genus level, whereas rpoB could discriminate Klebsiella at the species and even subspecies level. Overall, the gene tree based on rpoB is more compatible with the currently accepted classification of Klebsiella than those based on 16S rRNA and khe genes, showing that rpoB can be a powerful tool for identification of K. pneumoniae isolates. Above all, our study challenges the utility of khe as a species-specific marker for identification of K. pneumoniae.

[An increased level of interleukin 27 in peripheral blood mononuclear cells and fibroblasts like synoviocytes of patients with rheumatoid arthritis or osteoarthritis].

OBJECTIVE: To detect the levels of interleukin 27 (IL-27) and its receptor in peripheral blood mononuclear cells (PBMCs) and fibroblasts like synoviocytes (FLS) of patients with rheumatoid arthritis (RA) or osteoarthritis (OA). METHODS: PBMCs were collected from 20 patients with RA, 20 patients with OA and 20 healthy controls. FLS were cultured from synovial tissues of 4 patients with RA and 4 patients with OA. The levels of IL-27 mRNA in PBMCs and FLS were measured using real-time quantitative PCR. The expression of IL-27Rα in FLS was detected using immunocytochemical method. RESULTS: The level of IL-27 mRNA in PBMCs of patients with RA or OA was 1.81 or 2.07 times of the level in the normal subjects, respectively. There was no significant difference in the IL-27 mRNA level between RA and OA. However, IL-27 mRNA level in FLS of the patients with RA was 3.74 times of the level in the patients with OA. IL-27Rα expression in FLS of RA group was higher than that in OA group. CONCLUSION: The level of IL-27 in patients with RA and OA increased, and the level of IL-27 in FLS was higher than that in PBMCs in RA patients.