Gyarmati et al. identify the central roles of glomerular mechanical forces as well as endothelial and immune cell activation early in Alport syndrome. The cover image shows intravital multiphoton microscopy imaging of immune cell features in a late-stage Alport syndrome model.
BACKGROUND. Vaccine-elicited adaptive immunity is a prerequisite for control of SARS-CoV-2 infection. Multiple sclerosis (MS) disease-modifying therapies (DMTs) differentially target humoral and cellular immunity. A comprehensive comparison of MS DMTs on SARS-CoV-2 vaccine-specific immunity is needed, including quantitative and functional B and T cell responses. METHODS. Spike-specific antibody and T cell responses were measured before and following SARS-CoV-2 vaccination in a cohort of 80 subjects, including healthy controls and MS patients in six DMT groups: untreated, glatiramer acetate (GA), dimethyl fumarate (DMF), natalizumab (NTZ), sphingosine-1-phosphate (S1P) receptor modulators, and anti-CD20 monoclonal antibodies. Anti-spike antibody responses were quantified by Luminex assay, high-resolution spike epitope reactivity was mapped by VirScan, and pseudovirus neutralization was assessed. Spike-specific CD4+ and CD8+ T cell responses were characterized by activation-induced marker (AIM) expression, cytokine production, and tetramer analysis. RESULTS. Anti-spike IgG levels were similar between healthy controls, untreated MS, GA, DMF, and NTZ patients, but were significantly reduced in anti-CD20 and S1P-treated patients. Anti-spike seropositivity in anti-CD20 patients was significantly correlated with CD19+ B cell levels and inversely correlated with cumulative treatment duration. Spike epitope reactivity and pseudovirus neutralization was reduced in anti-CD20 and S1P patients, directly correlating with reduced spike receptor binding domain (RBD) IgG levels. Spike-specific CD4+ and CD8+ T cell reactivity remained robust across all groups except in S1P-treated patients in whom post-vaccine CD4+ T cell responses were attenuated. CONCLUSIONS. These findings from a large MS cohort exposed to a wide spectrum of MS immunotherapies have important implications for treatment-specific COVID-19 clinical guidelines. FUNDING. This work was supported by grants from the NIH 1K08NS107619 (JJS), NMSS TA- 1903-33713 (JJS), K08NS096117 (MRW), Westridge Foundation (MRW), Chan Zuckerberg Biohub (JLD), R01AI159260 (JAH), R01NS092835 (SSZ), R01AI131624 (SSZ), R21NS108159 (SSZ), NMSS RG1701-26628 (SSZ), and the Maisin Foundation (SSZ).
Joseph J. Sabatino Jr, Kristen Mittl, William M. Rowles, Kira McPolin, Jayant V. Rajan, Matthew T. Laurie, Colin R. Zamecnik, Ravi Dandekar, Bonny D. Alvarenga, Rita P. Loudermilk, Chloe Gerungan, Collin M. Spencer, Sharon A. Sagan, Danillo G. Augusto, Jessa R. Alexander, Joseph L. DeRisi, Jill A. Hollenbach, Michael R. Wilson, Scott S. Zamvil, Riley Bove
Aristolochic acid (AA) is the causative nephrotoxic alkaloid in aristolochic acid nephropathy, which results in a tubulointerstitial fibrosis. AA causes direct proximal tubule damage. There is also an influx of macrophages, although their role in the pathogenesis is poorly understood. Here we demonstrate that AA directly stimulates migration, inflammation, and reactive oxygen species (ROS) production in macrophages ex vivo. Cells lacking interferon regulatory factor 4 (IRF4), a known regulator of macrophage migration and phenotype, had a reduced migratory response, though effects on ROS production and inflammation were preserved or increased relative to wild-type cells. Macrophage-specific IRF4 knockout mice were protected from both acute and chronic kidney effects of AA administration based on functional and histological analysis. Renal macrophages from kidneys of AA-treated macrophage-specific IRF4 knockout mice demonstrated increased apoptosis and ROS production compared with wildtype controls, indicating that AA directly polarizes macrophages to a promigratory and proinflammatory phenotype. However, knockout mice had reduced renal macrophage abundance following AA administration. While macrophages lacking IRF4 can adopt a proinflammatory phenotype upon AA exposure, their inability to migrate to the kidney and increased rates of apoptosis upon infiltration provide protection from AA in vivo. These results provide evidence of direct AA effects on macrophages in AAN and add to the growing body of evidence that supports a key role of IRF4 in modulating macrophage function in kidney injury.
Kensuke Sasaki, Andrew S. Terker, Jiaqi Tang, Shirong Cao, Juan Pablo Arroyo, Aolei Niu, Suwan Wang, Xiaofeng Fan, Yahua Zhang, Stephanie R. Bennett, Ming-zhi Zhang, Raymond C. Harris
Mammalian skeletal muscle contains heterogenous myofibers with different contractile and metabolic properties that sustain muscle mass and endurance capacity. The transcriptional regulators that govern these myofiber gene programs have been elucidated. However, the hormonal cues that direct the specification of myofiber types and muscle endurance remain largely unknown. Here we uncover the secreted factor Tsukushi (TSK) as an extracellular signal that is required for maintaining muscle mass, strength, and endurance capacity, and contributes to muscle regeneration. Mice lacking TSK exhibited reduced grip strength and impaired exercise capacity. Muscle transcriptomic analysis revealed that TSK deficiency results in a remarkably selective impairment in the expression of myofibrillar genes characteristic of slow-twitch muscle fibers that is associated with abnormal neuromuscular junction formation. AAV-mediated overexpression of TSK failed to rescue these myofiber defects in adult mice, suggesting that the effects of TSK on myofibers are likely restricted to certain developmental stages. Finally, mice lacking TSK exhibited diminished muscle regeneration following cardiotoxin-induced muscle injury. These findings support a crucial role of TSK as a hormonal cue in the regulation of contractile gene expression, endurance capacity, and muscle regeneration.
Qiuyu Wang, Xiaoxue Qiu, Tongyu Liu, Cheehoon Ahn, Jeffrey F. Horowitz, Jiandie D. Lin
Recent research on altering threat memory has focused on a reconsolidation window. During reconsolidation, threat memories are retrieved and become labile. Reconsolidation of distinct threat memories is synapse-dependent whereas the underlying regulatory mechanism of the specificity of reconsolidation is poorly understood. We designed a unique behavioral paradigm in which a distinct threat memory can be retrieved through the associated conditioned stimulus. In addition, we proposed a regulatory mechanism by which the activation of acid-sensing ion channels (ASICs), strengthens the distinct memory trace associated with the memory reconsolidation to determine its specificity. The activation of ASICs by carbon dioxide (CO2) inhalation when paired with memory retrieval, triggers the reactivation of the distinct memory trace, resulting in greater memory lability. ASICs potentiate the memory trace by altering the amygdala-dependent synaptic transmission and plasticity at selectively targeted synapses. Our results suggest that inhaling CO2 during the retrieval event increases the lability of a threat memory through a synapse-specific reconsolidation process.
Erin E. Koffman, Charles M. Kruse, Kritika Singh, Farzaneh Sadat Naghavi, Melissa A. Curtis, Jennifer Egbo, Mark Houdi, Boren Lin, Hui Lu, Jacek Debiec, Jianyang Du
BACKGROUND. Most subjects with prior COVID-19 disease manifest long–term, protective immune responses against re-infection. Accordingly, we tested the hypothesis that humoral immune and reactogenicity responses to a SARS-CoV-2 mRNA vaccine differ in subjects with and without prior COVID-19. METHODS. Health care workers (n=61) with (n=30) and without (n=31) prior COVID-19 disease received two, 30 µg doses of Pfizer BNT162b2 vaccine 3 weeks apart. Serum IgG antibody against the Spike receptor-binding domain (RBD); serum neutralizing activity; and vaccine reactogenicity were assessed longitudinally every 2 weeks for 56 days after the 1st injection. RESULTS. The COVID group manifested more rapid increases in Spike IgG antibody and serum neutralizing activity post 1st vaccine dose but showed little or no increase after the 2nd dose compared to the infection-naïve group. In fact, Spike IgG was maximum after the 1st dose in 36% of the COVID group versus 0% of the infection-naïve group. Peak IgG antibody was lower but appeared to fall more slowly in the COVID-19 versus the infection-naïve group. Finally, adverse systemic reactions e.g., fever, headache and malaise, were more frequent and lasted longer after both the 1st and 2nd injection in the COVID group than in the infection-naïve group. CONCLUSION. Subjects with prior COVID-19 demonstrate a robust, accelerated humoral immune response to the 1st dose but attenuated response to the 2nd dose of BNT162b2 vaccine compared to controls. The COVID-19 group also experiences greater reactogenicity. Humoral responses and reactogenicity to BNT162b2 differ qualitatively and quantitatively in subjects with prior COVID-19 compared to infection-naive subjects. FUNDING. This work was supported by Institutional Funds.
Steven G. Kelsen, Alan S. Braverman, Mark O. Aksoy, Jacob A. Hayman, Puja S. Patel, Charu Rajput, Huaqing Zhao, Susan G. Fisher, Michael R. Ruggieri Sr., Nina T. Gentile
JCI This Month is a digest of the research, reviews, and other features published each month.