Although most autoimmune diseases are considered to be CD4 T-cell or antibody-mediated, many respond to CD20-depleting antibodies that have limited influence on CD4 and plasma cells. This includes rituximab that is used in cancer, rheumatoid arthritis and off-label in a large number of other autoimmunities, notably multiple sclerosis, where ofatumumab is in late stage development and ocrelizumab is approved for use. Recently, the COVID-19 pandemic created concerns about immunosuppression in autoimmunity, leading to cessation or a delay in immunotherapy treatments. However, based on the known and emerging biology of multiple sclerosis and COVID-19, it was hypothesised that whilst B-cell depletion should not necessarily expose people to severe SARS-CoV-2-related issues, it may inhibit protective immunity following infection and vaccination. As such, drug-induced B-cell subset inhibition that controls multiple sclerosis and other autoimmunities, would not influence innate and CD8 T-cell responses, which are central to SARS-CoV-2 elimination, nor the hyper-coagulation and innate inflammation causing severe morbidity. This is supported clinically, as the majority (mortality rate n=~5/392) of SARS-CoV-2 infected, CD20-depleted people with multiple sclerosis have recovered. However, protective neutralising-antibody and vaccination responses are predicted to be blunted, until naïve B-cells repopulate, based on B-cell repopulation-kinetics and vaccination responses, from published rituximab and unpublished ocrelizumab (NCT00676715, NCT02545868) trial data, shown here. This suggests that it may be possible to undertake dose-interruption to maintain inflammatory disease control in MS and other autoimmune diseases, whilst allowing effective vaccination against SARS-CoV-29, if and when an effective vaccine is available.
Tuberculosis (TB) is one of the top 10 causes of mortality worldwide from a single infectious agent and has significant implications for global health. In 2018, 1.5 million people died from TB worldwide and 440,000 of those were from India. The WHO End-TB strategy aims to reduce TB deaths by 95% and new TB cases by 90% by 2035, with a call for more basic research on TB pathogenesis and immunity. A major hurdle in the development of effective TB vaccines and therapies is the absence of defined immune-correlates of protection. In this context, the role of regulatory T cells (Treg), which are essential for maintaining immune homeostasis, is even less understood. This review aims to address this knowledge gap by providing an overview of the emerging patterns of Treg function in TB. The review also provides a comprehensive critical analysis of the key features of Treg cells in TB; highlights the importance of a balanced immune response as being important in TB and discusses the importance of probing not just Treg frequency but also qualitative aspects of Treg function as part of a comprehensive search for novel TB treatments.
Peroxiredoxins (PRXs) are intracellular antioxidative enzymes but work as inflammatory amplifiers under the extracellular condition. To date, the function of PRXs in the pathogenesis of multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) is not fully understood. The aim of this study was to investigate whether PRXs play a role in the pathogenesis of MS and NMOSD. We analyzed levels of PRXs (PRX1, PRX5, and PRX6) in the CSF and serum of 16 patients with MS, 16 patients with NMOSD, and 15 patients with other neurological disorders (ONDs). We identified potential correlations between significantly elevated PRXs levels and the clinical variables in patients with MS and NMOSD. Additionally, pathological analyses of PRXs (PRX1-6) in the central nervous system were performed using the experimental autoimmune encephalomyelitis (EAE), animal model of MS. We found that serum levels of PRX5 and PRX6 in patients with MS and NMOSD were higher compared with those in patients with ONDs (p < 0.05). Furthermore, high levels of PRX5 and PRX6 were partly associated with blood–brain barrier dysfunction and disease duration in NMOSD patients. No significant elevation was found in CSF PRXs levels of MS and NMOSD. Spinal cords from EAE mice showed remarkable PRX5 staining, especially in CD45+ infiltrating cells. In conclusion, PRX5 and PRX6 may play a role in the pathogeneses of MS and NMOSD.
Background: Cladribine (CdA), an oral prodrug approved for the treatment of relapsing multiple sclerosis, selectively depletes lymphocytes. CdA passes the blood-brain barrier suggesting a potential effect on CNS resident cells. Objective: We examined, if CdA modifies the phenotype and function of naïve and activated primary mouse microglia, when applied in different concentrations including 0.1-1 µM that putatively overlaps human CSF concentrations. Methods: Primary microglia cultures without stimulation or in the presence of proinflammatory lipopolysaccharide (LPS) or anti-inflammatory IL-4 were co-treated with different concentrations of CdA for 24 hours. Viability was assessed by MTT assay. Phagocytotic ability and morphology were examined by flow cytometry, and random migration by IncuCyte Zoom and TrackMate. Change in gene expression was examined by qPCR, and protein secretion by Meso Scale Discovery. Results: LPS and IL-4 upregulated deoxycytidine kinase (DCK) expression. Only activated microglia were affected by CdA, and this was unrelated to viability. CdA 0.1-1 µM significantly reduced granularity, phagocytotic ability and random migration of activated microglia. CdA 10 µM increased the IL-4-induced gene expression of Arg1 and LPS-induced expression of IL-1beta, TNF, iNOS, and Arg1, but protein secretion remained unaffected. CdA 10 µM potentiated the increased expression of anti-inflammatory TNFR2 but not TNFR1 induced by LPS. Conclusion: Microglia acquire a less activated phenotype when treated with 0.1–1 µM CdA that putatively overlaps human CSF concentrations. This may be related to the upregulated gene expression of DCK upon activation and suggests a potential alternative mechanism of CdA with direct effect on CNS resident cells.
Properdin is the only one positive regulator of the complement system. In this study, we characterize the prevalence, functional consequences and disease associations of autoantibodies against properdin in a cohort of patients with autoimmune disease systemic lupus erythematosus (SLE), suffering from lupus nephritis (LN). We detected autoantibodies against properdin in plasma of 22.5% of the LN patients (16/71) by ELISA. The binding of these autoantibodies to properdin was dose-dependent and was validated by surface plasmon resonance. Higher levels of anti-properdin were related to high levels of anti-dsDNA and ANA and to low concentrations of C3 and C4 in patients and also with histological signs of LN activity and chronicity. The high negative predictive value (NPV) of anti-properdin and anti-dsDNA combination suggested that patients who are both negative for anti-properdin and anti-dsDNA will not have severe nephritis. IgG from anti- properdin positive patients’ plasma increased the C3b deposition on late apoptotic cells by flow cytometry. Nevertheless, these IgGs did not modify substantially the binding of properdin to C3b, the C3 convertase C3bBb and the pro-convertase C3bB, evaluated by surface plasmon resonance. In conclusion, anti- properdin autoantibodies exist in LN patients. They have weak but relevant functional consequences, which could have pathological significance.
The aim of this study was to investigate the pathogenesis of combination ipilimumab and nivolumab-associated colitis (IN-COL) by measuring gut-derived and peripheral blood mononuclear cell (GMNC; PBMC) profiles. We studied GMNC and PBMC from patients with IN-COL, IN-treated with no adverse-events (IN-NAE), ulcerative colitis (UC) and healthy volunteers by flow cytometry. In the gastrointestinal-derived cells we found high levels of activated CD8+ T cells and mucosal-associated invariant T (MAIT) cells in IN-COL, changes that were not evident in IN-NAE or UC. UC but not IN-C was associated with a high proportion of regulatory T cells (Treg). We sought to determine if local tissue responses could be measured in peripheral blood. Peripherally, checkpoint-inhibition instigated a rise in activated memory CD4+ and CD8+ T cells, regardless of colitis. Low circulating MAIT cells at baseline was associated with IN-COL patients, compared with IN-NAE in one of two cohorts. UC but not IN-COL was associated with high levels of circulating plasmablasts. In summary, the alterations in T cell subsets measured in IN-COL-affected tissue, characterised by high levels of activated CD8+ T cells and MAIT cells and a low proportion of Treg, reflected a pathology distinct from UC. These tissue changes differed from the periphery, where T cell activation was a widespread on-treatment effect, and circulating MAIT cell count was low but not reliably predictive of colitis (Figure1).
Background: Pulmonary sarcoidosis is characterized by an exaggerated CD4+ T-cell response and formation of non-necrotizing granulomas. Tumour necrosis factor α (TNF-α) is regarded as crucial for granuloma formation and TNF-α inhibitors offer a 3rd line treatment option for patients not responding to conventional treatment. However, not all patients benefit from treatment, and an optimal dose and treatment duration have not been established. Insight into the influence of TNF-α inhibitors on lung immune cells may provide clues to what drives inflammation in sarcoidosis and improve our understanding of treatment outcomes. Objectives: To evaluate effects of treatment with the TNF- α inhibitor infliximab on lung immune cells and clinical features of the patients. Methods: Thirteen patients with sarcoidosis refractory to conventional treatment were assessed with bronchoalveolar lavage (BAL), spirometry and CT scan in close adjacent to start of infliximab treatment. These investigations were repeated after six months of treatment. Results: Treatment with TNF- α inhibitor infliximab was well tolerated with no adverse events, except for one patient who developed a probable adverse event with liver toxicity. Ten patients were classified as responders, having a reduced CD4/CD8 ratio, a decreased percentage of CD4+ T-cells expressing the activation marker CD69 and number of mast cells (p<0.05 for all). The percentage of T regulatory cells (Tregs), defined as FoxP3+ CD4+ T-cells decreased in most patients. Conclusions: Six months of infliximab treatment in patients with sarcoidosis led to signs of decreased CD4+ T-cell alveolitis and decreased mastocytosis in the lungs of responders.
Though the pathogenesis of acute myeloid leukemia (AML) is still unknown, accumulating evidence has revealed that immune response plays a vital part in the pathogenesis. Here, we investigated the involvement of 24 single-nucleotide polymorphisms (SNPs) of immuno-related genes, including cytokines (IL2, IL4, IL9, IL-12A, IL-22, IFNG, and TGFB1), transcriptional regulatory genes (TBX21, STAT1, STAT3, STAT5B, STAT6, GATA3, FOXP3, and IRF4), and others (IL2RA IL6R NFKBIA), in 269 AML inpatients and 200 healthy controls. Furthermore, we analyzed the relationship between the SNPs and clinical characteristics. Immuno-related SNP genotyping was performed on the Sequenom MassARRAY iPLEX platform. All the SNPs in healthy controls were consistent with Hardy–Weinberg equilibrium. All final p values were adjusted by Bonferroni multiple testing. Our results showed that IL-22 (rs2227491) was significantly associated with the white blood cell (WBC) counts. STAT5B (rs6503691) showed a close relationship with the recurrent genetic abnormalities in patients with AML. We verified the negatively independent effect of age and risk of cytogenetics on overall survival (OS). More importantly, the GG genotype of IL-12A (rs6887695) showed a negative impact on AML prognosis independently. Furthermore, the relative expression of IL-12 was decreased in GG genotype, no matter under codominant or recessive model. However, no correlation was observed between the SNPs mentioned above and disease susceptibility, risk stratification, and survival. Our findings suggest that immuno-related gene polymorphisms are associated with prognosis in AML, which may perform as novel inspection targets for AML patients.
Background NOD-like receptor pyrin 7 (NLRP7) has been identified as the major gene responsible for the recurrent hydatidiform mole (RHM). The immunological role of NLRP7 mutation in HM patients has not been conclusively demonstrated. Hence, we aim to demonstrate this role in our study. Methods We followed 12 new patients with NLRP7 nonsynonymous variations (NSVs) from date to date. Peripheral blood mononuclear cells (PBMCs) were collected from patients with and without NLRP7 mutation, separately. Supernatant IL-1β secretion, intracellular pro-IL-1β and mature-IL-1β expressions were measured after 24h lipopolysaccharide (LPS) stimulation. Plasmids with corresponding NSVs were generated to evaluate the ability of processing pro-IL-1β into mature-IL-1β in vitro. Results Homozygous or compound heterozygous NLRP7 mutation secreted less IL-1β in root of abnormal intracellular pro-IL-1β or mature-IL-1β according to different domain defective. Plasmids with NSVs could also affect processing or/and trafficking together with caspase-1 and apoptosis-associated speck-like protein (ASC). Conclusion Inflammasome related NLRP7 mutation is a potential mechanism of RHM.