Faculty Bibliography

This retrospective, single-center study aimed to characterize and compare the kinetics of B-cell reemergence following anti-CD20 infusion (anti-CD20i) in African American (AA) and white patients with MS or NMOSD. In a logistic regression model that included race, time since anti-CD20i, body mass index, and diagnosis, only AA race (p=0.01) and time since anti-CD20i (p=0.0003) were significant predictors of B-cell repletion. However, B-cell subset composition was similar between AA and white patients with detectable CD19+ B-cell counts. These findings highlight the importance of including a diverse study population in future studies of anti-CD20 therapies.

Imbalances in the gut microbiome are suspected contributors to the pathogenesis of Systemic Lupus Erythematosus, and our studies and others have documented that patients with active Lupus nephritis have expansions of the obligate anaerobe, Blautia (Ruminococcus) gnavus (RG). To investigate whether the RG strains in Lupus patients have in vivo pathogenic properties in a gnotobiotic system, we colonized C57BL/6 mice with individual RG strains from healthy adults or those from Lupus patients. These strains were similar in their capacity for murine intestinal colonization of antibiotic-preconditioned specific-pathogen-free, as well as of germ-free adults and of their neonatally colonized litters. Lupus-derived RG strains induced high levels of intestinal permeability that was significantly greater in female than male mice, whereas the RG species-type strain (ATCC29149/VPI C7-1) from a healthy donor had little or no effects. These Lupus RG strain-induced functional alterations were associated with RG translocation to mesenteric lymph nodes, and raised serum levels of zonulin, a regulator of tight junction formation between cells that form the gut barrier. Notably, the level of Lupus RG-induced intestinal permeability was significantly correlated with serum IgG anti RG cell-wall lipoglycan antibodies, and with anti-native DNA autoantibodies that are a biomarker for SLE. Strikingly, gut permeability was completely reversed by oral treatment with larazotide acetate, an octapeptide that is a specific molecular antagonist of zonulin. Taken together, these studies document a pathway by which RG strains from Lupus patients contribute to a leaky gut and features of autoimmunity implicated in the pathogenesis of flares of clinical Lupus disease.

BACKGROUND:The etiology of systemic lupus erythematosus (SLE) is multifactorial. Recently, growing evidence suggests that the microbiota plays a role in SLE, yet whether gut microbiota participates in the development of SLE remains largely unknown. To investigate this issue, we carried out 16 s rDNA sequencing analyses in a cohort of 18 female un-treated active SLE patients and 7 female healthy controls, and performed fecal microbiota transplantation from patients and healthy controls to germ-free (GF) mice. RESULTS:Compared to the healthy controls, we found no significant different microbial diversity but some significantly different species in SLE patients including Turicibacter genus and other 5 species. Fecal transfer from SLE patients to GF mice caused GF mice to develop a series of lupus-like phenotypic features, including increased serum autoimmune antibodies, imbalanced cytokines, altered distribution of immune cells in mucosal and peripheral immune response, and upregulated expression of genes related to SLE in recipient mice that received SLE fecal microbiota transplantation (FMT). Moreover, the metabolism of histidine was significantly altered in GF mice treated with SLE patient feces, as compared to those which received healthy fecal transplants. CONCLUSIONS:Overall, our results describe a causal role of aberrant gut microbiota in contributing to the pathogenesis of SLE. The interplay of gut microbial and histidine metabolism may be one of the mechanisms intertwined with autoimmune activation in SLE.

Objective: To compare humoral and T-cell responses to COVID- 19 vaccines in 400 MS patients who were on Ocrelizumab ('OCR') v. other disease-modifying therapies ('non-OCR') at the time of vaccination. Introduction: Peripheral B-cell depletion with anti-CD20 therapies attenuates humoral responses to vaccines. Whether immune responses to COVID-19 vaccines differ between B-cell depleted and non-B cell depleted MS patients is not known.
Method(s): Consecutive MS patients from NYU MS Care Center were invited to participate if they completed COVID-19 vaccination >=6 weeks previously. Immune testing included anti-spike RBD antibody (Elecsys Anti-SARS-CoV-2) (Roche Diagnostics); multiplex bead-based immunoassays of antibody-responses to SARS-COV-2 spike proteins; T-cell responses to SARS-CoV-2 Spike protein using IFNgamma enzyme-linked immune-absorbent spot (Invitrogen) and TruCulture (Myriad RBM) assays; high dimensional immunophenotyping; and live virus immunofluorescencebased microneutralization assay.
Result(s): As of 7/15/2021, 105 MS subjects were enrolled (mean age: 40.5 years; 76% female; 41% non-white; 38% on OCR; 12% with prior COVID-19 infection). 95% were fully vaccinated with mRNA vaccines (Pfizer/Moderna); 5% - with adenovirus-based vaccine (Johnson&Johnson). Median time from sample collection to last vaccine was 79 days. Positive Elecsys Anti-SARS-CoV-2 Ab titers post-vaccine were detected in 11/37 (30%) in OCR (mean level: 702 U/mL among seropositives) and 54/54 (100%) patients in non-OCR (mean level: 2310 U/mL; p<0.0001). Positive response by multiplex assay (threshold of 'positive' defined as 2 SD below the mean for the non-OCR) were detected in 10/27 (37%) OCR and 29/31 (94%) non-OCR (p<0.00001). T-cell activation based on induced IFNgamma secretion (TruCulture) was detected in 20/25 (80%) OCR and 16/19 (84%) non-OCR patients (p=0.71).
Conclusion(s): Preliminary results suggest robust T-cell immune response to SARS-CoV2 vaccines in approximately 80% of both OCR and non-OCR MS patients. Antibody responses were markedly attenuated in OCR compared to non-OCR group. Updated results will be presented

Objective: To examine antibody and T-cell responses to mRNAplatform COVID-19 vaccines in Ocrelizumab-treated MS patients over a 12-month period. Introduction: B-cell depletion with Ocrelizumab attenuates humoral responses to vaccines. The kinetics of humoral and cellular immune responses to COVID-19 vaccines in B-cell depleted MS patients has not been reported.
Method(s): VIOLA (NCT04843774) is an open-label, observational study enrolling 60 MS patients on Ocrelizumab from NYU and Rocky Mountain at the University of Colorado MS Centers. First vaccine dose occurred >=2 weeks after ocrelizumab infusion; second-dose >=8 weeks before the next infusion. Antibody responses to SARS-COV-2 spike proteins were assessed with Elecsys Anti-SARS-CoV-2 (Roche Diagnostics) and multiplex bead-based immunoassays. T-cell responses to SARS-CoV-2 Spike protein were assessed with IFNgamma ELISpot (Invitrogen) and TruCulture (Myriad RBM) and high-dimensional immunophenotyping. Samples are collected pre-vaccination and at 4, 12, 24, and 48-weeks post-vaccination.
Result(s): As of 7/15/2021, 52 subjects have been enrolled (39.7+/-10.0 years; 73% female; 47% non-white), of whom 47 were fully vaccinated (85% Pfizer, 15% Moderna). Anti-spike RBD antibody (Elecsys Anti-SARS-CoV-2) were available for pre- and post-vaccine timepoints for 15 patients. Pre-vaccine, 1/15 (7%) patients had detectable titers, while at 4-weeks postvaccine, 10/15 (66%) patients had detectible titers (mean for positives: 1189 U/ml; 5 patients had positive titers <25 U/ml). T-cell activation based on induced IFNgamma secretion (TruCulture) at baseline and 4-week post-vaccine timepoints were available for 13 patients, of whom 12 (92%) were increased (mean pre-vaccine: 24 pg/ml; mean post-vaccine: 366 pg/ml, two-tailed t-test, p=0.0032).
Conclusion(s): This prospective study of humoral and cellular immune responses to COVID-19 vaccines in Ocrelizumab-treated patients will generate data to help guide management of MS patients on anti-CD20 therapies. Early results suggest that 4-weeks post-vaccination nearly all Ocrelizumab-treated MS patients develop T-cell immunity and two-thirds showed evidence of humoral response. Additional 4-week and 12-week post-vaccination data will be presented

Maintenance of immune homeostasis involves a synergistic relationship between the host and the microbiome. Canonical interferon (IFN) signaling controls responses to acute microbial infection, through engagement of the STAT1 transcription factor. However, the contribution of tonic levels of IFN to immune homeostasis in the absence of acute infection remains largely unexplored. We report that STAT1 KO mice spontaneously developed an inflammatory disease marked by myeloid hyperplasia and splenic accumulation of hematopoietic stem cells. Moreover, these animals developed inflammatory bowel disease. Profiling gut bacteria revealed a profound dysbiosis in the absence of tonic IFN signaling, which triggered expansion of T_H17 cells and loss of splenic T_reg cells. Reduction of bacterial load by antibiotic treatment averted the T_H17 bias and blocking IL17 signaling prevented myeloid expansion and splenic stem cell accumulation. Thus, tonic IFNs regulate gut microbial ecology, which is crucial for maintaining physiologic immune homeostasis and preventing inflammation.

Antibodies to double-stranded DNA (dsDNA) are prevalent in systemic lupus erythematosus (SLE), particularly in patients with lupus nephritis, yet the nature and regulation of antigenic cell-free DNA (cfDNA) are poorly understood. Null mutations in the secreted DNase DNASE1L3 cause human monogenic SLE with anti-dsDNA autoreactivity. We report that >50% of sporadic SLE patients with nephritis manifested reduced DNASE1L3 activity in circulation, which was associated with neutralizing autoantibodies to DNASE1L3. These patients had normal total plasma cfDNA levels but showed accumulation of cfDNA in circulating microparticles. Microparticle-associated cfDNA contained a higher fraction of longer polynucleosomal cfDNA fragments, which bound autoantibodies with higher affinity than mononucleosomal fragments. Autoantibodies to DNASE1L3-sensitive antigens on microparticles were prevalent in SLE nephritis patients and correlated with the accumulation of cfDNA in microparticles and with disease severity. DNASE1L3-sensitive antigens included DNA-associated proteins such as HMGB1. Our results reveal autoantibody-mediated impairment of DNASE1L3 activity as a common nongenetic mechanism facilitating anti-dsDNA autoreactivity in patients with severe sporadic SLE.

The report from El-Gabalawy and coworkers represents an important chapter in their studies of rheumatoid arthritis (RA) in a unique First Nation (FN) patient cohort and their at-risk first-degree relatives (FDR)(1). These members of the Cree and Chippewa tribes in rural Manitoba Canada share racial/ethnic (and presumed genetic) features distinct from other RA cohorts. Here, the investigators show that during the preclinical phase, when patients were asymptomatic, these FN FDR express serum RA disease-associated anti-citrullinated protein antibodies (ACPA), anti-carbamylated protein antibodies and rheumatoid factors (RFs).

Staphylococcus aureus, a common cause of serious and often fatal infections, is well-armed with secreted factors that disarm host immune defenses. Highly expressed in vivo during infection, Staphylococcal protein A (SpA) is reported to also contribute to nasal colonization that can be a prelude to invasive infection. Co-evolution with the host immune system has provided SpA with an Fc-antibody binding site, and a Fab-binding site responsible for non-immune superantigen interactions via germline-encoded surfaces expressed on many human BCRs. We wondered whether the recurrent exposures to S. aureus commonly experienced by adults, result in the accumulation of memory B-cell responses to other determinants on SpA. We therefore isolated SpA-specific class-switched memory B cells, and characterized their encoding VH : VL antibody genes. In SpA-reactive memory B cells, we confirmed a striking bias in usage for VH genes, which retain the surface that mediates the SpA-superantigen interaction. We postulate these interactions reflect co-evolution of the host immune system and SpA, which during infection results in immune recruitment of an extraordinarily high prevalence of B cells in the repertoire that subverts the augmentation of protective defenses. Herein, we provide the first evidence that human memory responses are supplemented by B-cell clones, and circulating-antibodies, that bind to SpA determinants independent of the non-immune Fc- and Fab-binding sites. In parallel, we demonstrate that healthy individuals, and patients recovering from S. aureus infection, both have circulating antibodies with these conventional binding specificities. These findings rationalize the potential utility of incorporating specially engineered SpA proteins into a protective vaccine.