Clinical & Translational Immunology最新文献

Objectives

The early development of humoral immunity is important for long-term protection of the newborn. Here, we set out to discern these infant-produced antibodies from the vast background of maternal antibodies, which is challenging but essential to shed light on the infant-produced repertoire.

Methods

Using IgA1 and IgG1 antibody clonal repertoire analysis by mass spectrometry, we compared matched maternal serum, maternal milk, and infant serum samples, both at birth (T1) and at 7–11 weeks after delivery (T2) in four mother–infant dyads.

Results

We observed for both IgA1 and IgG1 unique infant-produced antibody repertoires at T2. For IgA1 at T2, no substantial clonal overlap was found between infant serum and breastmilk. The serum IgG1 clonal repertoires were highly alike at birth for mother and infant, but at T2, the contribution of the maternal clonal population in the infant had been drastically reduced, and a large portion of the T2 IgG1 repertoire originated from the infant.

Conclusions

Newborns produce their own antibody repertoires as early as a few months after birth. From this small study, no convincing evidence is found for transfer of milk antibodies into the infant circulation.

Objective

Examine the role of T cells in shaping and sustaining humoral immunity to SARS-CoV-2 and identify immune factors associated with durable antibody responses.

Methods

Unvaccinated adults (n = 67) with SARS-CoV-2 infection (Wuhan) of any severity were followed longitudinally for up to 14 months. Anti-Spike (S) binding and neutralising antibodies were measured. Bulk T cell IFNγ and IL-2 responses were assessed by Fluorospot to multiple viral proteins. S-specific T-cell subsets and functions were analysed in detail by flow cytometry in a subset of participants (n = 14), combining activation-induced markers (AIMs) and cytokines. Correlations between S-specific T-cell subsets, their polyfunctionality and antibody levels over time were defined.

Results

Over 14 months post infection, anti-S IgG and neutralising antibodies declined significantly but remained detectable in > 85% of participants. Bulk T-cell IFNγ and IL-2 responses persisted without significant reduction. However, S-specific CD4 T cells declined over time. A large proportion of these were peripheral helper T cells (Tph; CXCR5⁻PD-1⁺), which were the main producers of IL-21 and showed marked polyfunctionality during early convalescence, in contrast to circulating follicular helper T cells (cTfh). The early presence of polyfunctional, IL-21-producing Tph strongly correlated with S-specific IgG and neutralising antibodies early post-infection and predicted neutralising antibody maintenance a year later. Older age correlated with higher Tph and antibody levels.

Conclusion

Early S-specific T-cell responses—particularly polyfunctional, IL-21-producing Tph cells—play a key role in sustaining durable antibody levels post-infection, offering insights for future vaccine strategies and understanding long-term immunity.

Allogeneic haematopoietic stem cell transplantation (HSCT) is the only curative therapy for patients diagnosed with acute myeloid leukaemia (AML) and myelodysplastic syndrome (MDS). γδ+ T-cells, a rare subpopulation of T-cells with both innate and adaptive anticancer functions, have been understudied and the role of different γδ+ T-cell subsets after HSCT is unclear.

Objectives

We aimed to characterise the γδ+ T-cells reconstitution post-HSCT, investigating their association with graft-versus-host disease (GvHD) treatment and occurrence, and cytomegalovirus (CMV) reactivation.

Methods

Peripheral blood samples from AML and MDS patients and their respective donors were immunophenotyped by flow cytometry before and at several time points after HSCT. Additionally, next-generation sequencing of the TRG locus was performed to assess clonal dynamics and repertoire diversity.

Results

Early after HSCT, γδ+ T-cells showed a similar phenotype compared to pre-HSCT, and stable repertoires were observed up to 6 months post-HSCT. Patients with acute GVHD presented a higher frequency of CD8 in γδ+ T-cells, and γδ+ T-cell and subsets frequencies were not affected by anti-thymocyte globulin prophylaxis. Donor-derived Vδ2+ T-cell central memory phenotype was associated with a reduced risk of CMV reactivation in the recipient and with repertoire disturbance. Effector memory cells displaying a specific HLA-DR+ CD86+ phenotype were associated with CMV reactivation and a higher proportion of hyperexpanded clonotypes prior to transplantation.

Conclusion

Overall, Vδ1+ and Vδ2+ T-cell phenotypic profiles and γδ TCR repertoire remain stable post-HSCT. This stability is disrupted by CMV reactivation, which is potentially associated with γδ+ T-cells of donor origin and γδ TCR repertoire.

Objectives

Lung complications occur commonly post-haematopoietic stem cell transplant (HCT) in children and contribute significantly to mortality. The development of biomarkers predictive of post-HCT lung complications may improve outcomes for these children. Therefore, the primary objective of this study was to identify pre-transplant plasma biomarkers predictive of lung complications in children undergoing HCT.

Methods

Plasma samples from 117 pre-HCT patients were used to measure 78 soluble immune analytes, and extensive clinical metadata were retrospectively collected from the electronic medical record, including clinical characteristics of the post-HCT lung complications.

Results

Firstly, we showed that the plasma cytokine signature of children undergoing HCT differed significantly between children depending on the indication for HCT (malignant vs non-malignant). Secondly, we found that the plasma cytokine signature changed with the age of the patient. Thirdly, we showed that elevated pre-HCT plasma levels of CXCL9 and Chitinase 3-like 1, both induced by IFN-γ, were predictive of post-HCT lung complications in patients with a malignant indication for HCT [area under the curve (AUC): 0.70, P = 0.0007 and AUC: 0.68, P = 0.0016, respectively].

Conclusion

In conclusion, we have identified two potential biomarkers of post-HCT lung disease in paediatric patients and these require validation in future cohorts.

Objectives

Multiple sclerosis is an immune-mediated inflammatory disease of the central nervous system. Recently, kappa opioid receptor (KOR) agonists were found to promote remyelination and recovery in models of demyelination. However, the side effects of many full KOR agonists limit clinical use. Activation of KOR and mu opioid receptors (MOR) often has opposing effects. Therefore, it is plausible that activating KOR and antagonising MOR may confer a beneficial increase in therapeutic efficacy at lower doses.

Methods

This study investigated the hypothesis that combining the clinically available full KOR agonist nalfurafine (NalF) with a MOR antagonist/partial KOR agonist nalmefene (NalM) would provide greater than additive benefits in the murine model of immune-driven demyelination, experimental autoimmune encephalomyelitis (EAE).

Results

We found that NalM alone reduced EAE disease severity when administered therapeutically although NalM at the most effective doses did not enhance myelination or reduce lesions in the spinal cord. Moreover, a combination of NalF/NalM at suboptimal doses significantly reduced lesion size and promoted myelination in the spinal cord suggesting a better-than-additive effect on lesion resolution. This finding was supported by a bioinformatic analysis response that highlighted the myelination benefits of the suboptimal dose combination while the optimal dose combination of NalF/NalM stimulated increased immunomodulatory activity.

Conclusions

Findings from this study indicate that the remyelinating and immunomodulatory effects of the KOR agonist NalF can be significantly enhanced through interactions with the MOR antagonist NalM in a distinct dose-dependent manner.

Objectives

Detection of antigen-specific T cells has been crucial for the study of autoimmune illnesses such as coeliac disease (CD). In CD, an oral gluten challenge is required to expand the rare population of circulating gluten-specific T cells to detectable levels for IFN-γ ELISpot detection. We evaluated interleukin (IL)-2 detection as a simpler approach to identify gluten-specific T cells in CD.

Methods

HLA-DQ2.5+-treated CD adults (n = 10) were assessed before and 6–8 days after commencing a single-bolus gluten challenge. Serum IL-2 (GCIL-2), whole blood IL-2 (WBA) and peripheral blood mononuclear cell IFN-γ ELISpot responses were evaluated. Functional effects of peptides encompassing epitopes of varying immunogenicity and pan-HLA-DQ blocking were tested.

Results

GCIL-2 was 90% sensitive in detecting CD. Day 6 post challenge was the optimal day for assessment. In vitro IL-2 release showed higher sensitivity than IFN-γ or IL-10 release in the WBA. IL-2 WBA had 80% sensitivity prior to gluten challenge, and 90% sensitivity at Day 6 post gluten challenge. IFN-γ ELISpot was less sensitive: 20% at baseline and 40% at Day 6 after gluten challenge. Pan-HLA-DQ blocking reduced IL-2 WBA responses by 89–91%, and the assay accurately ranked gluten peptide immunogenicity consistent with published data.

Conclusions

The IL-2 WBA provides superior sensitivity over IFN-γ ELISpot for detecting gluten-specific T cells. It can measure the functional blockade of HLA and accurately reflects gluten peptide immunogenicity hierarchies. The IL-2 WBA supports immunomonitoring and T-cell epitope mapping in CD and offers broad research and clinical application beyond CD.

Objectives

Immunisation remains the most cost-effective mechanism to combat influenza infection and is widely employed against seasonal influenza viruses. Zoonotic transmission of avian influenza A viruses represents a significant threat to human health given the lack of population-level immunity. Therefore, there is a need to better understand pre-existing cross-reactive human immunity against avian influenza strains, as highlighted by the recent global spread of avian H5Nx clade 2.3.4.4b variants.

Methods

Here, we quantified the frequencies and specificities of B and T cells recognising avian hemagglutinin (HA) within unexposed adults and characterised the ability of seasonal immunisation to boost cross-reactive immune responses to H5Nx strains, including from clade 2.3.4.4b.

Results

Low but detectable serum antibody titres against H5 and H7 avian influenza HA were observed in donors. The frequency of memory B cells with cross-reactive recognition of H5 and H7 HA was below 0.13% and two- to five-fold lower than populations of seasonal HA-specific B cells. Boosting of B-cell responses against clade 2.3.4.4b H5Nx HA following seasonal immunisation was sporadic with only three of 19 individuals showing an increased population of probe-positive cells. Cross-reactive B cells generally expressed immunoglobulins drawn from variable heavy chain genes associated with HA stem recognition. CD4⁺ T-cell responses towards H5 HA were weakly boosted with little increase in circulating T follicular helper cell populations.

Conclusion

These findings highlight the need for avian influenza-specific vaccine products to bolster immunity in human populations. Such vaccines could aid pre-pandemic preparedness by expanding baseline frequencies of avian influenza-specific memory lymphocytes.

Objectives

To describe the first reported case of coexisting Synovitis, Acne, Pustulosis, Hyperostosis, and Osteitis (SAPHO) syndrome and IgG4-related disease (IgG4-RD) and to evaluate the therapeutic response to Upadacitinib.

Methods

We described the clinical course, investigations, treatments, and outcomes of a 45-year-old woman initially diagnosed with SAPHO syndrome who subsequently developed IgG4-RD. Laboratory tests, imaging findings, and therapeutic responses were analyzed.

Results

The patient developed IgG4-RD-related organ involvement during the course of SAPHO syndrome. Although glucocorticoid therapy was initially effective, disease flares occurred upon tapering. Upadacitinib was initiated as an escalation therapy, leading to rapid improvement in clinical symptoms and normalization of inflammatory and IgG4-related serological markers. Sustained remission was maintained with continued treatment.

Conclusion

This case demonstrates that Upadacitinib may be an effective therapeutic option for patients with concurrent SAPHO syndrome and IgG4-RD. The observed clinical response supports the potential role of JAK-STAT pathway modulation in managing overlapping immune-mediated disorders.

Objectives

Despite advancements in surgical techniques and perioperative care, pancreatic surgery remains a high-risk procedure with significant morbidity and mortality. Furthermore, understanding its impact on the immune system is essential for designing strategies that interact with it. The aim of this study was to elucidate the immunomodulation that occurs following pancreatectomy.

Methods

Patients were recruited for the IMMUNOPANC trial (NCT03978702). We performed mass cytometry to analyse the circulating immune subpopulations and integrated the data using the hierarchical-stochastic neighbour embedding clustering analysis and Stabl algorithm.

Results

Among the enrolled 39 patients, 33 (84.5%) had undergone pancreatectomy for neoplasia including 13 (39%) with pancreatic ductal adenocarcinoma. Twelve (32%) patients developed pancreatic fistula with a 90-day mortality rate of 2.5%. We phenotyped 156 samples and observed a significant increase in myeloid cells (26% vs. 34%, P = 0.018) after pancreatectomy. Natural killer cell proportions decreased on postoperative day one (POD1) compared with the preoperative levels (7% vs. 12%, P < 0.001). Similarly, both CD8⁺ and CD4⁺ T-cell proportions decreased significantly post-surgery (25% and 40%, respectively, P < 0.001). During a narrow window, we observed the alteration of NK cells, contraction of CD8⁺ T cells, and increase in the proportion of naive CD4⁺ T cells. These changes may be a result of the immune response to surgery but could also reflect lymphoid organ demargination.

Conclusion

This study presents the first analysis of peripheral immune system trajectories following pancreatic surgery. Understanding these dynamics would facilitate the restoration of postoperative immunity, which is potentially crucial for recovery.

Objectives

Graft-versus-host disease (GVHD) is an inflammatory disorder that arises following allogeneic haematopoietic stem cell transplantation. P2X7 is an extracellular ATP-gated cation channel present on immune cells. P2X7 blockade with small molecule inhibitors impairs GVHD development in a humanised mouse model. This study investigated whether adeno-associated viral (AAV) vectors encoding nanobodies (Nbs) that block mouse P2X7 (mP2X7) or both mP2X7 and human P2X7 (m/hP2X7) impair GVHD development in this model.

Methods

On Day −21, NOD.Cg-Prkdc^scidIl2rg^tm1Wjl/SzJ (NSG) mice were injected intramuscularly with 10 × 10¹⁰ viral genomes encoding either green fluorescent protein (GFP), an anti-mP2X7 Nb or an anti-m/hP2X7 Nb, or with saline. On Day 0, mice were euthanised or injected intraperitoneally with 10 × 10⁶ human peripheral blood mononuclear cells and monitored thrice weekly for signs of GVHD until the experiment or disease endpoint.

Results

The anti-m/hP2X7 and anti-mP2X7 Nbs reduced clinical GVHD and time to disease onset, as well as liver and lung GVHD. Both Nbs reduced liver human T helper (Th)17 cells. Sera collected at Day 0 and disease endpoint from treated mice, but not from control mice, completely blocked P2X7 activity in human RPMI 8226 and/or murine J774 cells, confirming circulating anti-P2X7 Nbs in mice from Day 0 to disease endpoint.

Conclusion

This study indicates that P2X7 blockade with an anti-m/hP2X7 and to a lesser extent an anti-mP2X7 Nb reduces GVHD progression in humanised mice. This supports the future testing of these P2X7 biologics as a prophylactic therapy for GVHD.