Streptococcal toxic shock syndrome (STSS) is a severe invasive infection characterized by the sudden onset of shock and multiorgan failure; it has a high mortality rate. Although a number of studies have attempted to determine the crucial factors behind the onset of STSS, the responsible genes in group A Streptococcus have not been clarified. We previously reported that mutations of csrS/csrR genes, a two-component negative regulator system for multiple virulence genes of Streptococcus pyogenes, are found among the isolates from STSS patients. In the present study, mutations of another negative regulator, rgg, were also found in clinical isolates of STSS patients. The rgg mutants from STSS clinical isolates enhanced lethality and impaired various organs in the mouse models, similar to the csrS mutants, and precluded their being killed by human neutrophils, mainly due to an overproduction of SLO. When we assessed the mutation frequency of csrS, csrR, and rgg genes among S. pyogenes isolates from STSS (164 isolates) and non-invasive infections (59 isolates), 57.3% of the STSS isolates had mutations of one or more genes among three genes, while isolates from patients with non-invasive disease had significantly fewer mutations in these genes (1.7%). The results of the present study suggest that mutations in the negative regulators csrS/csrR and rgg of S. pyogenes are crucial factors in the pathogenesis of STSS, as they lead to the overproduction of multiple virulence factors.

Signaling pathways from TLRs are mediated by the Toll/IL-1R (TIR) domain-containing adaptor molecules. TNF receptor-associated factor (TRAF) 6 is thought to activate NF-κB and MAPKs downstream of these TIR domain-containing proteins to induce production of inflammatory cytokines. However, the precise role of TRAF6 in signaling from individual TLRs has not been appropriately addressed. We analyzed macrophages from TRAF6-deficient mice and made the following observations. In the absence of TRAF6, 1) ligands for TLR2, TLR5, TLR7, and TLR9 failed to induce activation of NF-κB and MAPKs or production of inflammatory cytokines; 2) TLR4 ligand-induced cytokine production was remarkably reduced and activation of NF-κB and MAPKs was observed, albeit with delayed kinetics; and 3) in contrast with previously reported findings, TLR3 signaling was not affected. These results indicate that TRAF6 is essential for MyD88-dependent signaling but is not required for TIR domain-containing adaptor-inducing IFN-β (TRIF)-dependent signaling.

BackgroundAdalimumab is a fully human, monoclonal antibody against tumor necrosis factor that is approved in Western countries for the treatment of moderately to severely active ulcerative colitis (UC).MethodsThis 52-week, phase 2/3, randomized, double-blind study evaluated adalimumab for induction and maintenance treatment in 273 anti-TNF–naive Japanese patients with UC who were refractory to corticosteroids, immunomodulators, or both. Patients received placebo, adalimumab 80/40 (80 mg at week 0, then 40 mg every other week), or adalimumab 160/80 (160/80 mg at weeks 0/2, then 40 mg every other week) in addition to background UC therapy.ResultsAt week 8, remission rates were similar among treatment arms, but more patients treated with adalimumab 160/80 achieved response (placebo, 35 %; 80/40, 43 %; 160/80, 50 %; P = 0.044 for 160/80 vs placebo) and mucosal healing (placebo, 30 %; 80/40, 39 %; 160/80, 44 %; P = 0.045 for 160/80 vs placebo) compared with placebo. At week 52, more patients receiving adalimumab 40 mg every other week achieved response (18 vs 31 %; P = 0.021), remission (7 vs 23 %; P = 0.001), and mucosal healing (16 vs 29 %; P = 0.015) compared with placebo. Week 8 response to adalimumab was associated with greater rates of response (61 %), remission (46 %), and mucosal healing (57 %) at week 52 relative to the overall population. Rates of serious adverse events were similar between treatment arms.ConclusionsInduction with adalimumab 160/80 mg led to early response and mucosal healing. Maintenance adalimumab had greater rates of long-term response, remission, and mucosal healing compared with placebo. No new safety signals were identified.Electronic supplementary materialThe online version of this article (doi:10.1007/s00535-013-0922-y) contains supplementary material, which is available to authorized users.

The clinical efficacy of a combination of adalimumab and azathioprine at WWeek 26 did not differ from that of adalimumab monotherapy in patients with Crohn's disease naïve to both medications.

Highlights d Qualitative changes in plasma neutralizing antibody are longitudinally analyzed d Affinity-matured antibodies with resistance to variants are durably maintained d Neutralizing potency and breadth to SARS-CoV-2 variants increase with time d Serological immunity evolves with time to counter SARS-CoV-2 variants