Clinical and experimental immunology最新文献

Introduction: Cladribine is a deoxyadenosine analogue that can penetrate the blood-brain barrier. It is used to treat multiple sclerosis (MS). However, the mechanistic understanding of the effect of this highly effective therapy on B cells and plasma cells in the central nervous system compartment is limited. The CLADRIPLAS study examined the effect of cladribine on peripheral and intrathecal B and plasma cell biology in people with MS.

Methods: Thirty-eight people with progressive MS ineligible for- or rejecting- treatment with licenced therapies were recruited and supplied a baseline lumbar puncture. Those exhibiting gadolinium-enhancing or new/enlarging T2 magnetic resonance imaging lesions and/or elevated neurofilament levels were offered subcutaneous cladribine (Litak®). Seven people were eligible; one person died before treatment, and only five completed the first year of treatment. Twenty-two ineligible people were willing to provide a repeat lumbar puncture twelve months later.

Results: The CLADRIPLAS study found no evidence of a difference in the odds of a positive cerebrospinal fluid oligoclonal band (cOCB) result between the cladribine-treated and untreated group. This is probably explained by microarray and in vitro studies, which demonstrated that plasmablasts and notably long-lived plasma cells are relatively resistant to the cytotoxic effect of cladribine compared to memory B cells at physiological concentrations. This was consistent with the loss of intracellular deoxycytidine kinase during antibody-secreting cell differentiation.

Conclusion: CLADRIPLAS indicates that cOCB are not rapidly eliminated in most people with MS. This may be explained by the relative lack of direct cytotoxic action of cladribine on long-lived plasma cells.

Introduction: To evaluate the characteristics of hematological parameters and peripheral inflammatory markers in migraine, including chronic migraine (CM) and episodic migraine (EM), and to explore their underlying mechanisms.

Method: A total of 88 subjects were enrolled, 58 with migraine (28 with chronic migraine and 30 with episodic migraine) and 30 healthy controls. All subjects were matched for age, gender and body mass index (BMI), and peripheral blood was collected. Hematological parameters and peripheral inflammatory markers (PIMs) were compared between migraineurs and healthy controls. The patients underwent hematological laboratory testing and calculated the PIMs. PIMs included neutrophil/lymphocyte ratio (NLR), lymphocyte/monocyte ratio (LMR), neutrophil/monocyte ratio (NMR), platelet/lymphocyte ratio (PLR), and platelet/monocyte ratio (PMR) ratio.

Result: Monocyte counts in migraine patients were significantly lower compared to healthy controls, while LMR and PMR were significantly higher. Statistically significant differences were observed in monocyte counts, LMR, and PMR among the three groups of CM, EM and HC patients. Post hoc Bonferroni t-test showed that monocyte counts were significantly lower in the EM group compared to the HC group, while LMR and PMR were significantly higher. Comparison between the EM and CM groups showed that LMR was significantly higher in the EM group. Differences in monocyte counts, LMR and PMR between the CM and HC groups were not statistically significant. Receiver operating characteristic (ROC) curve analysis indicated that the area under the curve (AUC) for the diagnosing migraine using the combination of Mon, LMR and PMR was 0.707, and the AUC for the diagnosis of EM was 0.758. The AUC value of PMR for diagnosing CM was 0.669, while the AUC for the combination of LMR and PLR in distinguishing CM and EM was 0.705.

Conclusion: Our findings indicate that migraine and its subtypes exhibit abnormalities in monocyte counts and PIMs, which possess diagnostic predictive value for differentiating migraine and its subtypes. This suggests that systemic inflammation may play a role in the pathogenesis of migraine.

Ischemic stroke and acute lung injury are prevalent life-threatening conditions marked by intricate molecular mechanisms and elevated mortality rates. Despite evident pathophysiological distinctions, a notable similarity exists in the gene responses to tissue injury observed in both pathologies. This similarity extends to both protein-encoding RNAs and non-coding RNAs. Extracellular vesicles (EVs) are nano-scale vesicles derived through cell secretion, possessing unique advantages such as high biocompatibility, low immunogenicity, intrinsic cell targeting, and facile chemical and genetic manipulation. Importantly, miRNAs, the most prevalent non-coding RNAs, are selectively concentrated within EVs. Macrophages/microglia serve as immune defense and homeostatic cells, deriving from progenitor cells in the bone marrow. They can be classified into two contrasting types: classical proinflammatory M1 phenotype or alternative anti-inflammatory M2 phenotype. However, there exists a continuum of various intermediate phenotypes between M1 and M2, and macrophages/microglia can transition from one phenotype to another. This review will investigate recent discoveries concerning the impact of EVs derived from macrophages/microglia under various states on the progression of ischemic stroke and acute lung injury. The focus will be on the involvement of miRNAs within these vesicles. The concluding remarks of this review will underscore the clinical possibilities linked to EV-miRNAs, accentuating their potential as both biomarkers and therapeutic targets.

Objective: Sjögren's Disease (SjD) subjects have decreased lacrimal/salivary gland function. Studies have proposed that autoantibodies targeting G-protein-coupled muscarinic acetylcholine-type-3-receptor (M3R) are potential clinical markers for SjD. We hypothesized that rabbits/mice immunized with 4-hydroxy-2-nonenal (HNE)-modified/unmodified Ro60 will develop an autoimmunity, specifically a SjD phenotype, thus expressing increased levels of anti-M3R antibodies.

Methods: We immunized two rabbits each with 10 mM HNE-modified Ro60/unmodified Ro60 antigen or Ro274-290/Ro413-428/Ro500-517 Ro60 peptides. Two rabbits each were immunized with either M3R second extracellular loop (ECL2) or M3R ECL3 peptide. Finally, five groups of BALB/c mice were immunized as follows-Group-I immunized with Ro60, Groups-II-IV immunized with Ro60 modified with 0.4 mM (low), 2 mM (medium) and 10 mM (high) HNE respectively and Group-V-Freund's adjuvant. Serum antibodies to M3R ECL2/ECL3/Ro60/La or Sm were detected by ELISA. Functional assays were also performed.

Results: Immunization with HNE-modified Ro60/unmodified Ro60 antigen or Ro274/Ro 413/Ro500 peptides induced a rapid intermolecular epitope spreading to M3R ECL2/ECL3, especially to M3R ECL3 in HNE-Ro immunized rabbits. These animals did not bind to scrambled M3R peptides. Ro60-immunized rabbit IgG inhibited M3R activity in a functional assay. Rabbits immunized with ECL2/ECL3 developed high reactivity to Ro60 but not against Sm/RNP. We found a differential antibody-induction against M3R ECL2 with Group-3 mice developing significant reactivity.

Conclusion: Our data show induction of increasing anti-M3R antibodies in rabbits immunized with Ro60/HNE-Ro60 or Ro60 peptides and differential induction of these antibodies in mice immunized with Ro60 modified with increasing HNE. These findings suggest that M3R ECL2/ECL3 are involved in SjD autoimmunity progression.

Introduction: Systemic Lupus Erythematosus (SLE) patients exhibit B-cell abnormalities. Although there are concerns about reduced antibody responses to SARS-CoV-2 vaccines, detailed data on B-cell-specific responses in SLE remain scarce. Understanding the responsiveness to novel vaccine-antigens, and boosters number, is important to avoid unnecessary prolonged isolation of immunocompromised individuals. We assessed humoral and antigen-specific B-cell subset responses, including changes in isotype switching, prior to and after several doses of SARS-CoV-2 vaccines.

Methods: Blood samples were obtained prior to and after SARS-CoV-2 vaccination from cross-sectional and longitudinal cohorts of previously uninfected patients with SLE (n=93). Healthy participants receiving SARS-CoV-2 vaccines were recruited as controls (n=135). We measured serum antibody titres, their neutralizing capacity, and vaccine-specific memory B cells subsets.

Results: Impaired IgG, IgA, and neutralizing responses against the original and various SARS-CoV-2 variants were observed following two doses of vaccine in SLE patients. Follow-up booster doses increased humoral responses compared to baseline, but they remained lower, with poorer neutralisation capacity against most strains, compared to healthy individuals after three or more doses. Analysis of memory B-cells subsets in SLE patients revealed an increase of SARS-CoV-2-specific isotype unswitched IgM+ over SARS-CoV-2-specific isotype switched IgG+/IgA+memory B-cells compared to healthy individuals. Culturing healthy naive B-cells with high levels of IFNα, a hallmark of SLE pathogenesis, prevented B-cells from switching to IgG under IgG-polarizing conditions.

Conclusion: SLE patients' protection against SARS-CoV-2 is overall impaired compared to healthy individuals and is associated with a class switch defect possibly due to chronic exposure of B-cells to IFNα.

Introduction: The apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) is crucial for inflammasome assembly and activation of several inflammasomes, including NLRP3. ASC aggregates are detected in human sera post pyroptotic cell death, but their inflammasome origin remains unclear.

Method: This study aimed to develop a method to detect ASC aggregates originating from NLRP3 inflammasomes. Initially, human monocytes, macrophages, and THP-1 ASC reporter cells were employed to validate the detection of ASC/NLRP3-positive events through flow cytometry.

Results: The presence of ASC/NLRP3 specks was confirmed in cell supernatants from monocytes and macrophages treated with LPS and nigericin or ATP. Flow cytometry analysis identified double-positive specks in patient sera from inflammatory conditions when compared to healthy controls. Elevated ASC/NLRP3 specks were observed in conditions such as CAPS and Schnitzler's syndrome.

Conclusion: We validated FACS as a reliable method for detecting ASC/NLRP3 specks in human sera, with potential diagnostic and monitoring applications in certain systemic autoinflammatory diseases.

Leniolisib, an oral, targeted phosphoinositide 3-kinase delta (PI3Kδ) inhibitor, was well-tolerated and efficacious versus placebo in treating individuals with activated PI3Kδ syndrome (APDS), an ultra-rare inborn error of immunity (IEI), in a 12-week randomised controlled trial. However, longer-term comparative data versus standard of care are lacking. This externally controlled study compared the long-term effects of leniolisib on annual rate of respiratory tract infections and change in serum immunoglobulin M (IgM) levels versus current standard of care, using data from the leniolisib single-arm open-label extension study 2201E1 (NCT02859727) and the European Society for Immunodeficiencies (ESID) registry. The endpoints were chosen following feasibility assessment considering comparability and availability of data from both sources. Baseline characteristics between groups were balanced through inverse probability of treatment weighting. The leniolisib-treated group included 37 participants, with 62 and 49 participants in the control group for the respiratory tract infections and serum IgM analyses, respectively. Significant reductions in the annual rate of respiratory tract infections (rate ratio: 0.34; 95% confidence interval [CI]: 0.19, 0.59) and serum IgM levels (treatment effect: -1.09 g/L; 95% CI: -1.78, -0.39, p=0.002) were observed in leniolisib-treated individuals versus standard of care. The results were consistent across all sensitivity analyses, regardless of censoring, baseline infection rate definition, missing data handling, or covariate selection. These novel data provide an extended comparison of leniolisib treatment versus standard of care, highlighting the potential for leniolisib to deliver long-term benefits by restoring immune system function and reducing infection rate, potentially reducing complications and treatment burden.

Introduction: Immune checkpoint inhibition (ICI) is highly effective for the treatment of melanoma, but intrinsic resistance is present in a subgroup of patients. TGF-β pathway activity may play a role in this resistance by preventing T-cells from entering the tumor microenvironment, causing immune escape. We investigated the association of TGF-β signal transduction pathway activity with resistance to ICI treatment in advanced melanoma. Furthermore, other pathway activities were analyzed to better understand their potential role in ICI resistance.

Method: The activity of 8 signaling pathways (TGF-β, Hedgehog, MAPK, AR, NOTCH, PI3K, JAK/STAT1-2, and NFkB) was analyzed from tumor tissue from patients with advanced melanoma. Pathway activity scores (PAS) were explored for associations with survival and response to ICI in 34 patients (19 non-responders and 15 responders). A second, independent method to investigate the predictive value of TGF-β pathway activation was conducted by determining levels of phosphorylated SMAD2.

Results: The mean TGF-β PAS of responders vs non-responders was 53.9 vs 56.8 (P = 0.265). No significant relation with progression-free survival was detected for TGF-β activity (P = 0.078). No association between pSMAD2 staining and treatment response or survival was identified. In contrast, Hedgehog scores of responders versus non-responders were 35.7 vs 41.6 (P = 0.038). High Hedgehog PAS was the sole significant predictor of resistance to ICI (OR 0.88, P = 0.033) and worse progression-free survival (HR 1-1.1, P = 0.012).

Conclusion: TGF-β pathway activation showed no significant relation with treatment response to ICI or survival in patients with advanced melanoma. Hedgehog PAS was identified as a possible biomarker associated with both treatment response and survival.