The Innate Immune Sensor NLRC3 Acts as a Rheostat that Fine-Tunes T Cell Responses in Infection and Autoimmunity.

Appropriate immune responses require a fine balance between immune activation and attenuation. NLRC3, a non-inflammasome-forming member of the NLR innate immune receptor family, attenuates inflammation in myeloid cells and proliferation in epithelial cells. T lymphocytes express the highest amounts of Nlrc3 transcript where its physiologic relevance is unknown. We show that NLRC3 attenuated interferon-γ and TNF expression by CD4+ T cells and reduced T helper 1 (Th1) and Th17 cell proliferation. Nlrc3-/- mice exhibited increased and prolonged CD4+ T cell responses to lymphocytic choriomeningitis virus infection and worsened experimental autoimmune encephalomyelitis (EAE). These functions of NLRC3 were executed in a T-cell-intrinsic fashion: NLRC3 reduced K63-linked ubiquitination of TNF-receptor-associated factor 6 (TRAF6) to limit NF-κB activation, lowered phosphorylation of eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1), and diminished glycolysis and oxidative phosphorylation. This study reveals an unappreciated role for NLRC3 in attenuating CD4+ T cell signaling and metabolism.

Multinucleated podocytes as a clue to diagnosis of juvenile nephropathic cystinosis.

BACKGROUND  : Cystinosis is a rare autosomal recessive lysosomal disorder that mainly affects the kidney and eye. Early treatment with cysteamine significantly improves the prognosis. However, early diagnosis of cystinosis, especially the juvenile nephropathic form, remains challenging because typical symptoms only become apparent in adulthood. We herein describe a 13-year-old girl who presented with proteinuria only but was diagnosed with juvenile nephropathic cystinosis based on multinucleated podocytes in her kidney biopsy specimen. We also studied the nephropathology of another case to determine the features of the multinucleated podocytes. CASE DIAGNOSIS: A previously healthy 13-year-old girl presented to our hospital because proteinuria had been detected in her school urine screening. She had been noted to have proteinuria on her school urine screening when she was 11 years of age but there was no consultation with her physician at that time. She was asymptomatic and had no other abnormalities on examination other than a relatively high urinary ß-2 microglobulin level. Her kidney biopsy showed 15 multinucleated podocytes in 34 glomeruli, and the mean number of nuclei per multinucleated podocyte was 4.4. Ophthalmological examination showed cystine crystals in her cornea. Her white blood cell cystine level was high, and she was diagnosed with juvenile nephropathic cystinosis. She started oral cysteamine treatment and showed almost no progression of the disease after 2 years. In another patient with juvenile nephropathic cystinosis, there were 25 multinucleated podocytes in 63 glomeruli, and the mean number of nuclei per multinucleated podocyte was 2.9. CONCLUSION: Early diagnosis is crucial to improve the prognosis of patients with cystinosis. This report emphasizes the importance of recognizing the unique pathological feature of multinucleated podocytes as an essential clue to the diagnosis of cystinosis.

STING Agonist Mitigates Experimental Autoimmune Encephalomyelitis by Stimulating Type I IFN-Dependent and -Independent Immune-Regulatory Pathways.

The cGAS-cyclic GMP-AMP (cGAMP)-stimulator of IFN genes (STING) pathway induces a powerful type I IFN (IFN-I) response and is a prime candidate for augmenting immunity in cancer immunotherapy and vaccines. IFN-I also has immune-regulatory functions manifested in several autoimmune diseases and is a first-line therapy for relapsing-remitting multiple sclerosis. However, it is only moderately effective and can induce adverse effects and neutralizing Abs in recipients. Targeting cGAMP in autoimmunity is unexplored and represents a challenge because of the intracellular location of its receptor, STING. We used microparticle (MP)-encapsulated cGAMP to increase cellular delivery, achieve dose sparing, and reduce potential toxicity. In the C57BL/6 experimental allergic encephalomyelitis (EAE) model, cGAMP encapsulated in MPs (cGAMP MPs) administered therapeutically protected mice from EAE in a STING-dependent fashion, whereas soluble cGAMP was ineffective. Protection was also observed in a relapsing-remitting model. Importantly, cGAMP MPs protected against EAE at the peak of disease and were more effective than rIFN-ß. Mechanistically, cGAMP MPs showed both IFN-I-dependent and -independent immunosuppressive effects. Furthermore, it induced the immunosuppressive cytokine IL-27 without requiring IFN-I. This augmented IL-10 expression through activated ERK and CREB. IL-27 and subsequent IL-10 were the most important cytokines to mitigate autoreactivity. Critically, cGAMP MPs promoted IFN-I as well as the immunoregulatory cytokines IL-27 and IL-10 in PBMCs from relapsing-remitting multiple sclerosis patients. Collectively, this study reveals a previously unappreciated immune-regulatory effect of cGAMP that can be harnessed to restrain T cell autoreactivity.

Aggressive immunotherapy combined with bortezomib and rituximab for membranous nephropathy associated with enzyme replacement therapy in Pompe disease.

BACKGROUND: Pompe disease (PD) is a lysosomal glycogen storage disorder caused by a deficiency in acid α-glucosidase (GAA) activity. Various organs, including the skeletal muscle, cardiac muscle, and liver, are commonly involved. Early initiation of enzyme replacement therapy (ERT) with recombinant human α-glucosidase (rhGAA) can improve the outcome. However, some patients experience a poor clinical course despite ERT because of the emergence of anti-rhGAA antibodies that neutralize rhGAA. Treatment against anti-rhGAA antibodies is challenging. CASE-DIAGNOSIS/TREATMENT: A 14-year-old boy with late-onset PD was referred to our hospital with proteinuria detected by school urinalysis screening. He was diagnosed with PD at the age of 4 years based on muscle biopsy and decreased GAA activity. Treatment with rhGAA was initiated, but anaphylaxis occurred frequently. Anti-rhGAA antibodies were detected and immune tolerance therapy was therefore given, but his antibody titer remained high. Kidney biopsy revealed stage II membranous nephropathy. Immunohistochemistry staining revealed anti-rhGAA antibody/rhGAA immune complexes along the glomerular capillary loop. Aggressive immunotherapy combined with bortezomib and rituximab was then initiated. Serum levels of anti-rhGAA antibodies decreased significantly and his proteinuria finally resolved. CONCLUSIONS: There have been few reports of membranous nephropathy associated with ERT for PD. We clarified the cause in the current patient. Bortezomib and rituximab effectively suppressed anti-rhGAA antibody production resulting in the resolution of proteinuria and maintenance of ERT efficacy.

Early predictive factors for progression to kidney failure in infants with severe congenital anomalies of the kidney and urinary tract.

BACKGROUND: Severe congenital anomalies of the kidney and urinary tract (CAKUT) progress to infantile kidney failure with replacement therapy (KFRT). Although prompt and precise prediction of kidney outcomes is important, early predictive factors for its progression remain incompletely defined. METHODS: This retrospective cohort study included patients with CAKUT treated at 12 centers between 2009 and 2020. Patients with a maximum serum creatinine level ≤ 1.0 mg/dL during the first 3 days, patients who died of respiratory failure during the neonatal period, patients who progressed to KFRT within the first 3 days, and patients lacking sufficient data were excluded. RESULTS: Of 2187 patients with CAKUT, 92 were finally analyzed. Twenty-five patients (27%) progressed to KFRT and 24 (26%) had stage 3-5 chronic kidney disease without replacement therapy during the median observation period of 52.0 (interquartile range, 22.0-87.8) months. Among these, 22 (24%) progressed to infantile KFRT. The kidney survival rate during the infantile period was significantly lower in patients with a maximum serum creatinine level during the first 3 days (Cr-day3-max) ≥ 2.5 mg/dL (21.8%) compared with those with a Cr-day3-max < 2.5 mg/dL (95.2%) (log-rank, P < 0.001). Multivariate analysis demonstrated Cr-day3-max (P < 0.001) and oligohydramnios (P = 0.025) were associated with higher risk of infantile KFRT. Eighty-two patients (89%) were alive at the last follow-up. CONCLUSIONS: Neonatal kidney function, including Cr-day3-max, was associated with kidney outcomes in patients with severe CAKUT. Aggressive therapy for severe CAKUT may have good long-term life outcomes through infantile dialysis and kidney transplantation. A higher resolution version of the Graphical abstract is available as Supplementary information.

Analysis of cases of severe respiratory failure in children with influenza (H1N1) 2009 infection in Japan.

Influenza (H1N1) 2009 occurred in Mexico in April 2009, quickly spread around the world, and was found in Japan in May. Many pediatric patients experienced encephalopathy, acute respiratory distress syndrome, and severe pneumonia. The subjects of this study were 31 pediatric patients who needed mechanical ventilation due to respiratory failure caused by influenza (H1N1) 2009 as reported to the Emergency Medical Information Center of the Japan Pediatric Society in Kanagawa Prefecture in Japan from August 1 to December 31, 2009. The diagnosis of influenza (H1N1) 2009 infection was based on positive results of a real-time polymerase chain reaction. No patient was diagnosed as having a bacterial infection. The average arterial PaO(2)/FiO(2) ratio was significantly decreased to 126. Atelectasis was revealed by chest X-ray in 90.3% of subjects. There was one plastic bronchitis patient. Anti-influenza drugs were used at an average of 14.9 h after onset. Five patients showed abnormal behavior as a complication of encephalopathy. We found that respiratory failure progressed rapidly. The type of respiratory failure was oxygenation failure. It was helpful to attempt to remove more sputum in these cases. Pediatric patients with respiratory failure from influenza (H1N1) 2009 should be carefully monitored for the onset of encephalopathy.

New-onset pediatric nephrotic syndrome following Pfizer-BioNTech SARS-CoV-2 vaccination: a case report and literature review.

Various new vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been rapidly developed. The new onset and recurrence of nephrotic syndrome triggered by some vaccines have been documented and several adult cases of minimal change nephrotic syndrome newly developing after SARS-CoV-2 vaccination have been reported. However, no reports of pediatric cases have been published. Indications for SARS-CoV-2 vaccines have been expanded to those as young as 12 years old and vaccination of children has just started in Japan. We encountered a 15-year-old boy without underlying disease who newly developed nephrotic syndrome after SARS-CoV-2 vaccination with BNT162b2 (Pfizer-BioNTech). He developed eyelid edema 4 days after vaccination and peripheral edema of the lower extremities a further 4 days later. Twenty-one days after vaccination, 60 mg of oral daily prednisolone was started. He achieved complete remission in 12 days without complications such as hypertension or acute kidney injury. We clinicians should be aware of the possibility of nephrotic syndrome developing after SARS-CoV-2 vaccination, not only in adults, but also in children.

Obesity Expands a Distinct Population of T Cells in Adipose Tissue and Increases Vulnerability to Infection.

Obesity in humans is associated with poorer health outcomes after infections compared with non-obese individuals. Here, we examined the effects of white adipose tissue and obesity on T cell responses to viral infection in mice. We show that lymphocytic choriomeningitis virus (LCMV) grows to high titer in adipose tissue. Virus-specific T cells enter the adipose tissue to resolve infection but then remain as a memory population distinct from memory T cells in lymphoid tissues. Memory T cells in adipose tissue are abundant in lean mice, and diet-induced obesity further increases memory T cell number in adipose tissue and spleen. Upon re-challenge infection, memory T cells rapidly cause severe pathogenesis, leading to increases in lipase levels, calcification of adipose tissue, pancreatitis, and reduced survival in obese mice but not lean mice. Thus, obesity leads to a unique form of viral pathogenesis involving memory T cell-dependent adipocyte destruction and damage to other tissues.

Identification of a Locus in Mice that Regulates the Collateral Damage and Lethality of Virus Infection.

Arenaviruses can cause severe hemorrhagic disease in humans, which can progress to organ failure and death. The underlying mechanisms causing lethality and person-to-person variation in outcome remain incompletely explained. Herein, we characterize a mouse model that recapitulates many features of pathogenesis observed in humans with arenavirus-induced hemorrhagic disease, including thrombocytopenia, severe vascular leakage, lung edema, and lethality. The susceptibility of congenic B6.PL mice to lymphocytic choriomeningitis virus (LCMV) infection is associated with increased antiviral T cell responses in B6.PL mice compared with C57BL/6 mice and is T cell dependent. Pathogenesis imparted by the causative locus is inherited in a semi-dominant manner in F1 crosses. The locus includes PL-derived sequence variants in both poorly annotated genes and genes known to contribute to immune responses. This model can be used to further interrogate how limited genetic differences in the host can remarkably alter the disease course of viral infection.