Memory T Cells Research Articles

Epidemic influenza virus nucleoprotein gene incorporated into vaccine influenza virus strain genome to optimize systemic and local T-cell immune response against live attenuated influenza vaccine

Introduction. Optimization of the vaccine-induced T-cell repertoire is one of the strategies to expand the spectrum of protective potential for live attenuated influenza vaccine (LAIV). LAIV cross-protective properties can be improved by introducing the nucleoprotein (NP) gene derived from epidemic parental virus into vaccine strain genome, i.e. by replacing the classical 6:2 genome formula with 5:3. The main objective of the present study was to detail evaluation for virus-specific systemic and tissue-resident memory T-cells subsets in mice immunized with seasonal H1N1 LAIV of the genome formula 6:2 and 5:3. Materials and methods. Two H1N1 LAIV strains with varying NP genes (LAIV 6:2 and LAIV 5:3) were generated using reverse genetics techniques. C57BL/6J mice were immunized intranasally with the vaccine candidates, twice, 3 weeks apart. Cells from the spleen and lung tissues were isolated 7 days after booster immunization to be stimulated with whole H1N1 influenza virus for assessing cytokine-producing memory CD44+CD62L– T-cells as well as expression of CD69 and CD103 surface markers using flow cytometry. Humoral murine serum immunity against H1N1 virus was assessed by ELISA. Results. The LAIV 5:3 vs classical 6:2 vaccine strain carrying the epidemic parental NP gene induced significantly more pronounced humoral immune response against recent influenza virus. The group of mice immunized with LAIV 5:3 demonstrated higher levels of virus-specific CD4+ and CD8+ effector memory T cells (TEM) in the spleen, including a subset of polyfunctional (IFNγ+TNFα+IL-2+) CD4+ TEM, compared to LAIV 6:2 group. Virus-specific memory T cell levels in lung tissues after immunization with LAIV 5:3 vs LAIV 6:2 also tended to increase, but no significant difference in stimulated tissue-resident CD69+CD103– and CD69+CD103+ T cells between the groups were found. Conclusion. Modification of the seasonal LAIV strain genome for updating its epitope composition allowed to enhance the virus-specific T-cell immune response both at systemic level and in lung tissues, thereby shoeing that the effectiveness of the vaccine against circulating influenza viruses can be potentially increased.

Dietary therapy of murine primary biliary cholangitis induces hepatocellular steatosis: A cautionary tale.

There is increased interest in utilizing dietary interventions to alter the progression of autoimmune diseases. These efforts are driven by associations of gut microbiota/metabolites with levels of short-chain fatty acids (SCFAs). Propionate is a key SCFA that is commonly used as a food preservative and is endogenously generated by bacterial fermentation of non-digestible carbohydrates in the gut. A thesis has suggested that a diet rich in propionate and other SCFAs can successfully modulate autoimmunity. Herein, we investigated the effect of long-term administration of propionylated high-amylose resistant starches (HAMSP) on the course of murine primary biliary cholangitis. Groups of female ARE-Del mice were fed an HAMSP diet either before or after disease onset. A detailed immunobiological analysis was performed involving autoantibodies and rigorous T-cell phenotyping, including enumeration of T-cell subsets in the spleen, liver, intestinal intraepithelial lymphocytes and lamina propria by flow cytometry. Histopathological scores were used to assess the frequency and severity of liver inflammation and damage to hepatocytes and bile ducts. Our results demonstrate that a long-term propionate-yielding diet re-populated the T-cell pool with decreased naïve and central memory T-cell subsets and an increase in the effector memory T cells in mice. Similarly, long-term HAMSP intake reduced CD4+CD8+ double-positive T cells in intraepithelial lymphocytes and the intestinal lamina propria. Critically, HAMSP consumption led to moderate-to-severe hepatocellular steatosis in ARE-Del mice, independent of the stage of autoimmune cholangitis. Our data suggest that administration of HAMSP induces both regulatory and effector T cells. Furthermore, HAMSP administration resulted in hepatocellular steatosis. Given the interest in dietary modulation of autoimmunity and because propionate is widely used as a food preservative, these data have significant implications. This study also provides new insights into the immunological and pathological effects of chronic propionate exposure.

Advances from targeted therapy for non-metastatic HER2-positive inflammatory breast cancer.

Among inflammatory breast cancer (IBC) patients, over one-third have HER2-overexpressing (HER2+) tumors. Pathologic complete response (pCR) rates to neoadjuvant targeted and chemotherapy for patients with HER2+ non-metastatic IBC now apporach 60% and favorable long-term survival rates are being reported for those with a pCR. Immune mechanisms contributing to this phenomenon include antibody-mediated immune activation and induction of memory T-cell reponses which may explain the sustained antitumor response seen after discontinuation of targeted therapies.

Experimentally investigated “CoronaDerm-PS”-driven SARS-CoV-2-specific cellular immunity and safety

Novel coronavirus disease 2019, caused by the SARS-CoV-2, initiate humoral and cellular immune responses against diverse virus antigens. The assessment of SARS-CoV-2-specific is mainly carried out in routine practice by determining specific immunoglobulins. However, high variability in S-protein structure in new genovariants of SARS-CoV-2 virus and the lack of correlation between specific antibodies and CD8+ T-lymphocytes underlie false negative responses, and mass assessment of cellular immunity is complicated due to the complexity of applying ELISPOT and cytofluorometry techniques. To solve this issue, a diagnostic method was developed for assessing SARS-CoV-2-specific cellular immune response, which is based on a skin test followed by evaluating a delayed-type hypersensitivity reaction involving antigen-specific memory T-lymphocytes. A diagnostic preparation CoronaDerm-PS is based on Cord_PS, which is a hybrid recombinant protein consisting of parts of the SARS-CoV-2 structural proteins S, M, N, E. The specific activity of this chimeric antigen was analyzed in cultured T-lymphocyte activation test by assessing interferon-γ production using cytofluorometry. To investigate the chimeric antigen specific activity, a preclinical safety study with CoronaDerm-PS preparation in experimental animals was conducted. A dose-dependent developing skin reaction was observed in 90–100% of guinea pigs vaccinated by EpiVacCorona, CoviVac, Gam-COVID-Vac, which confirms a potential for assessing post-vaccination cellular immunity using CoronaDerm-PS preparation. Upon this, the presence of functionally active T-cell-antigenic epitopes in the recombinant polypeptide allows to evaluate SARS-CoV-2-specific response illustrated by detected response after Gam-COVID-Vac (S-protein) and EpiVacCorona (N-protein) vaccination. Thus, a skin test based on CoronaDerm-PS preparation may be a promising diagnostic tool for rapid mass screening requiring no specialized laboratory equipment for assessing populational SARS-CoV-2-specific immunity. Such a test is distinguished by advantages such as ease of analysis, high specificity and sensitivity. The final decision-making on using this test in a real-world practice may achieved after conducting further clinical safety and effectiveness trials.

FASLG as a Key Member of Necroptosis Participats in Acute Myocardial Infarction by Regulating Immune Infiltration.

Acute myocardial infarction (AMI) is a major cause of human health risk. Necroptosis is a newly and recently reported mode of cell death, whose role in AMI has not been fully elucidated. This study aimed to search for necroptosis biomarkers associated with the occurrence of AMI and to explore their possible molecular mechanisms through bioinformatics analysis. The dataset GSE48060 was used to perform weighted gene co-expression network analysis (WGCNA) and differential analysis. Key modules, differential genes, and necroptosis-related genes (NRGs) were intersected to obtain candidate biomarkers. Groups were classified and differentially analyzed according to the expression of the key biomarker. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, gene set enrichment analysis (GSEA), and construction of protein-protein interaction (PPI) networks are performed on differentially expressed genes (DEGs). Finally, CIBERSORT was used to assess immune cell infiltration in AMI and the correlation of key biomarkers with immune cells. Immune cell infiltration analysis revealed the correlation between FASLG and multiple screened immune cells. WGCNA determined that the MEsaddlebrown module was the most significantly associated with AMI. Intersecting it with DEGs as well as NRGs, we obtained two key genes, FASLG and IFNG. But only FASLG showed statistically significant differences between the AMI group and the normal control group. Further analysis suggested that the down-regulation of FASLG may exert its function through the regulation of the central genes CD247 and YES1. Furthermore, FASLG was positively correlated with T-cell CD4 memory activation and T-cell gamma delta, and negatively correlated with macrophage M0. In conclusion, FASLG and its regulatory genes CD247 and YES1 might be involved in the development of AMI by regulating immune cell infiltration. FASLG might be a potential biomarker for AMI and provides a new direction for the diagnosis of AMI.

Immunopathogenesis of Lung in Fatal COVID-19 Cases in Erbil, Iraq

Coronavirus disease 2019 (COVID-19) infection is caused by severe acute respiratory syndrome coronavirus-2 (SARS-Cov-2). It is characterized by respiratory distress, multiorgan dysfunction and death in some cases. The host immune response to SARS-CoV-2 appears to play a critical role in disease pathogenesis and clinical manifestation. However the pathological mechanism underling the disease has not been fully defined. Lung autopsy samples from 3 patients with fatal COVID-19 were evaluated using hematoxylin and eosin stain to analyze the histopathological changes. While immunohistochemical (IHC) staining was performed for detecting CD4 in helper T-cells, CD8 in cytotoxic T-cells, CD56 in NK-cells and CD45RO in memory T-cells. Histopathological examination revealed features of diffuse alveolar damage (DAD) with exudate in alveolar space and infiltration of inflammatory cells. Immunohistochemistry staining for CD4 showed weak to positive staining, CD8 showed weak positive staining, CD56 showed negative staining, while CD45RO showed a positive staining. It can be concluded that SARS-CoV-2 virus impaired innate immune response through a decrease in NK cells and adaptive immune response through a decrease in CD8 T cells which is one of the explanations of the destructive nature of SARS-CoV-2 virus.

Interleukin-2-mediated CD4 T-cell activation correlates highly with effective serological and T-cell responses to SARS-CoV-2 vaccination in people living with HIV.

People living with HIV (PLWH) despite having an appreciable depletion of CD4+ T-cells show a good severe acute respiratory syndrome coronavirus 2 vaccination response. The underlying mechanism(s) are currently not understood. We studied serological and polyfunctional T-cell responses in PLWH receiving anti-retroviral therapy stratified on CD4+ counts as PLWH-high (CD4≥ 500 cells/mm3) and PLWH-low (<500 cells/mm3). Responses were assessed longitudinally before the first vaccination (T0), 1-month after the first dose (T1), 3-months (T2), and 6-months (T3) after the second dose. Expectedly, both PLWH-high and -low groups developed similar serological responses after T2, which were also non-significantly different from age and vaccination-matched HIV-negative controls at T3. The immunoglobulin G titers were also protective showing a good correlation with angiotensin-converting enzyme 2-neutralizations (R = 0.628, p = 0.005). While surface and intracellular activation analysis showed no significant difference at T3 between PLWH and controls in activated CD4+CD154+ and CD4+ memory T-cells, spike-specific CD4+ polyfunctional cytokine expression analysis showed that PLWH preferentially express interleukin (IL)-2 (p < 0.001) and controls, interferon-γ (p = 0.017). CD4+ T-cell counts negatively correlated with IL-2-expressing CD4+ T-cells including CD4+ memory T-cells (Spearman ρ: -0.85 and -0.80, respectively; p < 0.001). Our results suggest that the durable serological and CD4+ T-cell responses developing in vaccinated PLWH are associated with IL-2-mediated CD4+ T-cell activation that likely compensates for CD4+ T-cell depletion in PLWH.

Cross-species single-cell RNA sequencing reveals divergent phenotypes and activation states of adaptive immunity in human carotid and experimental murine atherosclerosis.

The distinct functions of immune cells in atherosclerosis have been mostly defined by preclinical mouse studies. Contrastingly, the immune cell composition of human atherosclerotic plaques and their contribution to disease progression is only poorly understood. It remains uncertain whether genetic animal models allow for valuable translational approaches. Single cell RNA-sequencing (scRNA-seq) was performed to define the immune cell landscape in human carotid atherosclerotic plaques. The human immune cell repertoire demonstrated an unexpectedly high heterogeneity and was dominated by cells of the T-cell lineage, a finding confirmed by immunohistochemistry. Bioinformatical integration with 7 mouse scRNA-seq data sets from adventitial and atherosclerotic vascular tissue revealed a total of 51 identities of cell types and differentiation states, of which some were only poorly conserved between species and exclusively found in humans. Locations, frequencies, and transcriptional programs of immune cells in mouse models did not resemble the immune cell landscape in human carotid atherosclerosis. In contrast to standard mouse models of atherosclerosis, human plaque leukocytes were dominated by several T-cell phenotypes with transcriptional hallmarks of T-cell activation and memory formation, T-cell receptor-, and pro-inflammatory signaling. Only mice at the age of 22 months partially resembled the activated T-cell phenotype. In a validation cohort of 43 patients undergoing carotid endarterectomy, the abundance of activated immune cell subsets in the plaque defined by multi-color flow cytometry associated with the extend of clinical atherosclerosis. Integrative scRNA-seq reveals a substantial difference in the immune cell composition of murine and human carotid atherosclerosis - a finding that questions the translational value of standard mouse models for adaptive immune cell studies. Clinical associations suggest a specific role for T-cell driven (auto-) immunity in human plaque formation and -instability.

Distinct epigenomic landscapes underlie tissue-specific memory T cell differentiation

The memory CD8+ Tcell pool contains phenotypically and transcriptionally heterogeneous subsets with specialized functions and recirculation patterns. Here, we examined the epigenetic landscape of CD8+ Tcells isolated from seven non-lymphoid organs across four distinct infection models, alongside their circulating Tcell counterparts. Using single-cell transposase-accessible chromatin sequencing (scATAC-seq), we found that tissue-resident memory T (TRM) cells and circulating memory T (TCIRC) cells develop along distinct epigenetic trajectories. We identified organ-specific transcriptional regulators of TRM cell development, including FOSB, FOS, FOSL1, and BACH2, and defined an epigenetic signature common to TRM cells across organs. Finally, we found that although terminal TEX cells share accessible regulatory elements with TRM cells, they are defined by TEX-specific epigenetic features absent from TRM cells. Together, this comprehensive data resource shows that TRM cell development is accompanied by dynamic transcriptome alterations and chromatin accessibility changes that direct tissue-adapted and functionally distinct Tcell states.

Aberrant innate immune profile associated with COVID-19 mortality in Pretoria, South Africa

The African continent reported the least number of COVID-19 cases and deaths of all the continents, although the exact reasons for this are still unclear. In addition, little is known about the immunological profiles associated with COVID-19 mortality in Africa. The present study compared clinical and immunological parameters, as well as treatment outcomes in patients admitted with COVID-19 in Pretoria, South Africa, to determine if these parameters correlated with mortality in this population. The in-hospital mortality rate for the cohort was 15.79%. The mortality rate in people living with HIV (PLWH) was 10.81% and 17.16% in people without HIV (p = 0.395). No differences in age (p = 0.099), gender (p = 0.127) or comorbidities were found between deceased patients and those who survived. All four of the PLWH who died had a CD4+ T-cell count <200 cells/mm3, a significantly higher HIV viral load than those who survived (p = 0.009), and none were receiving antiretroviral therapy. Seven of 174 (4%) patients had evidence of auto-antibodies neutralizing Type 1 interferons (IFNs). Two of the them died, and their presence was significantly associated with mortality (p = 0.042). In the adjusted model, the only clinical parameters associated with mortality were: higher fraction of inspired oxygen (FiO2) (OR: 3.308, p = 0.011) indicating a greater need for oxygen, high creatinine (OR: 4.424, p = 0.001) and lower platelet counts (OR: 0.203, p = 0.009), possibly secondary to immunothrombosis. Overall, expression of the co-receptor CD86 (p = 0.021) on monocytes and percentages of CD8+ effector memory 2 T-cells (OR: 0.45, p = 0.027) was lower in deceased patients. Decreased CD86 expression impairs the development and survival of effector memory T-cells. Deceased patients had higher concentrations of RANTES (p = 0.003), eotaxin (p = 0.003) and interleukin (IL)-8 (p < 0.001), all involved in the activation and recruitment of innate immune cells. They also had lower concentrations of transforming growth factor (TGF)-β1 (p = 0.40), indicating an impaired anti-inflammatory response. The immunological profile associated with COVID-19 mortality in South Africa points to the role of aberrate innate immune responses.

Detection and characterization of autoreactive memory stem T-cells in children with acute immune thrombocytopenia

Primary immune thrombocytopenia (ITP) is an acquired autoimmune disorder characterized by an isolated decrease in platelets below 100 × 109/l after the exclusion of other conditions associated with thrombocytopenia. We investigated the role of different memory T-cell subsets, including T stem cell memory (TSCM), in children diagnosed with primary ITP and its association with therapeutic duration. This case–control study included 39 pediatric patients with acute ITP admitted to the Children's Hospital at Assiut University. Using a FACSCanto flow cytometer, CD8 + and CD4 + T-lymphocytes were gated. Five different subsets were characterized in each of these cells according to CD45RO and CD45RA expression. Afterward, gating was performed based on CCR7, CD95, and CD27. Examination of the CD8 + T cells subpopulation showed that Central memory T (TCM) and CD8+ Naïve T (TN) cells were significantly lower in ITP patients than in healthy children (p < 0.0001) and (p = 0.01), respectively. In addition, CD8 + TEMRA was significantly higher in ITP children than in controls (p = 0.001). CD4 + TCM cells were significantly lower in the ITP patient group (p = 0.04). However, CD4 + TEM was significantly higher in patients than controls (p = 0.04). Our research found that ITP patients had an imbalance in the ratio of CD4+ to CD8+ T cells in the peripheral blood and that TCM cells may be involved in the pathogenetic mechanism of ITP. TCMs could help in prediction of patients with higher risk of developing ITP.

Immune Cell Dynamics in EGFR-Mutated NSCLC Treated With Afatinib and Pembrolizumab: Results From a Phase IB Study

IntroductionEGFR-mutated NSCLC is minimally responsive to programmed cell death protein 1 or programmed death-ligand 1 blockade. We evaluated the safety, tolerability, and immunomodulatory effects of the EGFR tyrosine kinase inhibitor (TKI) afatinib in combination with the programmed cell death protein 1 antibody pembrolizumab in patients with EGFR-mutant NSCLC. MethodsPatients with advanced EGFR-mutant NSCLC with progression (PD) on previous EGFR TKI(s), aged above or equal to 18 years, Eastern Cooperative Oncology Group performance status less than or equal to 1, acceptable organ function, no significant autoimmune disease, measurable disease, and controlled brain metastases were eligible. Primary end point was determination of the maximum tolerated dose and recommended phase 2 dose. Serial specimens were collected to assess for alterations in cytokines and immune cell subsets by quantitative immunofluorescence in tissue and Luminex and flow cytometry in the blood. ResultsA total of 11 patients were enrolled, six in dose finding and five in dose expansion. No dose-limiting toxicities were observed. The maximum tolerated dose was determined to be afatinib 40 mg orally daily and pembrolizumab 200 mg intravenously every 21 days. Four (36%) patients had immune-related adverse events (irAEs). Ten patients were assessable for response: two partial response, seven stable disease, and one PD. Peripheral natural killer and natural killer T-cells (p = 0.027, p = 0.01) increased and exhausted CD8+ T-cells decreased on treatment (p = 0.0035). Peripheral CD4/CD8 T-cells (area under the curve = 0.96, p = 0.042) and central memory T-cells (CD4/CD8) (area under the curve = 1.0, p = 0.0006) increased in patients who had disease control more than 6 months or partial response to afatinib/pembrolizumab as did CD3+ T-cells in a patient with progression-free survival more than 6 months after afatinib/pembrolizumab treatment. ConclusionsAfatinib and pembrolizumab were found to have modest activity associated with irAEs after PD on previous EGFR TKI setting. Proinflammatory changes in immune cell subsets in tissue and blood were detected and associated with antitumor activity and irAEs.

An mRNA vaccine for pancreatic cancer designed by applying in silico immunoinformatics and reverse vaccinology approaches.

Pancreatic ductal adenocarcinoma is the most prevalent pancreatic cancer, which is considered a significant global health concern. Chemotherapy and surgery are the mainstays of current pancreatic cancer treatments; however, a few cases are suitable for surgery, and most of the cases will experience recurrent episodes. Compared to DNA or peptide vaccines, mRNA vaccines for pancreatic cancer have more promise because of their delivery, enhanced immune responses, and lower proneness to mutation. We constructed an mRNA vaccine by analyzing S100 family proteins, which are all major activators of receptors for advanced glycation end products. We applied immunoinformatic approaches, including physicochemical properties analysis, structural prediction and validation, molecular docking study, in silico cloning, and immune simulations. The designed mRNA vaccine was estimated to have a molecular weight of 165023.50 Da and was highly soluble (grand average of hydropathicity of -0.440). In the structural assessment, the vaccine seemed to be a well-stable and functioning protein (Z score of -8.94). Also, the docking analysis suggested that the vaccine had a high affinity for TLR-2 and TLR-4 receptors. Additionally, the molecular mechanics with generalized Born and surface area solvation analysis of the "Vaccine-TLR-2" (-141.07 kcal/mol) and "Vaccine-TLR-4" (-271.72 kcal/mol) complexes also suggests a strong binding affinity for the receptors. Codon optimization also provided a high expression level with a GC content of 47.04% and a codon adaptation index score 1.0. The appearance of memory B-cells and T-cells was also observed over a while, with an increased level of helper T-cells and immunoglobulins (IgM and IgG). Moreover, the minimum free energy of the mRNA vaccine was predicted at -1760.00 kcal/mol, indicating the stability of the vaccine following its entry, transcription, and expression. This hypothetical vaccine offers a groundbreaking tool for future research and therapeutic development of pancreatic cancer.

Oxidized Melanoma Antigens Promote Activation and Proliferation of Cytotoxic T-Cell Subpopulations.

Increasing evidence suggests the role of reactive oxygen and nitrogen species (RONS) in regulating antitumor immune effects and immunosuppression. RONS modify biomolecules and induce oxidative post-translational modifications (oxPTM) on proteins that can alarm phagocytes. However, it is unclear if and how protein oxidation by technical means could be a strategy to foster antitumor immunity and therapy. To this end, cold gas plasma technology producing various RONS simultaneously to oxidize the two melanoma-associated antigens MART and PMEL is utilized. Cold plasma-oxidized MART (oxMART) and PMEL (oxPMEL) are heavily decorated with oxPTMs as determined by mass spectrometry. Immunization with oxidized MART or PMEL vaccines prior to challenge with viable melanoma cells correlated with significant changes in cytokine secretion and altered T-cell differentiation of tumor-infiltrated leukocytes (TILs). oxMART promoted the activity of cytotoxic central memory T-cells, while oxPMEL led to increased proliferation of cytotoxic effector T-cells. Similar T-cell results are observed after incubating splenocytes of tumor-bearing mice with B16F10 melanoma cells. This study, for the first time, provides evidence of the importance of oxidative modifications of two melanoma-associated antigens in eliciting anticancer immunity.

Humoral and cellular immune response after mRNA SARS-CoV-2 vaccine in children on treatment for cancer: A pilot observational study

Immunocompromised children are at risk of developing severe COVID-19 infection. We conducted a pilot prospective study to evaluate the impact of cancer treatment and stem cell transplantation on immunogenicity of two doses of BNT162b2 vaccine in pediatric patients.Humoral, B- and T-cell responses to the BNT162b2 vaccine were assessed before, after the first and the second dose in patients aged 5–12 years (n = 35) and in a group of healthy donors (HD, n = 12). Patients were divided in three groups: solid tumors (ST, n = 11), hematological malignancies (HM, n = 14) and Hematopoietic Stem Cell Transplantation (HSCT) recipients (n = 10). After two vaccine doses, the seroconversion rate was 79.3 % (72.7 % in ST, 66.7 % in HM and 100 % in HSCT). The antibodies production was not associated to the presence of memory B and T-cells. Memory B-cells were measurable in 45.5 % ST, 66.6 % HSCT and in 22.0 % HM. The specific T-cell response was observed in most ST (81.8 %) and HSCT (85.7 %) patients and at lesser extent in those with HM (55.5 %). The combination of all immunological parameters (antibodies, memory B and T cells) showed that a significant fraction of HM (33.3 %) and ST (18.2 %) patients completely failed to respond to vaccination. Although able to produce antibodies, 11.1 % of HM and 27.3 % of ST had no B- and T-cell memory. HSCT subgroup showed the best immune function, with 80 % complete response and optimal T-cell function.Combination of anti-RBD antibody, and specific memory B- and T-cell responses represents a reliable read-out of vaccine immune efficacy in frail patients.

RhIL-7-hyFc, a long-acting interleukin-7, improves efficacy of CAR-T cell therapy in solid tumors

BackgroundChimeric antigen receptor T-cell (CAR-T) therapy has achieved remarkable remission in patients with B-cell malignancies. However, its efficacy in treating solid tumors remains limited. Here, we investigated a combination therapy...

Memory T-cell dynamics following immunization with a polyvalent salmonellosis vaccine in farm animals

Memory T-cell dynamics following immunization with a polyvalent salmonellosis vaccine in farm animals

Solute Transporter OCTN1/Slc22a4 Affects Disease Severity and Response to Infliximab in Experimental Colitis: Role of Gut Microbiota and Immune Modulation

Abstract Background Inflammatory bowel diseases are chronic disabling conditions with a complex and multifactorial etiology, still incompletely understood. OCTN1, an organic cation transporter, could have a role in modulating the inflammatory response, and some genetic polymorphisms of this molecule have been associated with increased risk of inflammatory bowel diseases. Until now, limited information exists on its potential in predicting/modulating patient’s response to therapies. The aim of this study was to evaluate the role of OCTN1 in modifying gut microbiota and mucosal immunity in response to infliximab therapy in murine colitis. Methods A dextran sodium sulphate model of colitis was used to assess the clinical efficacy of infliximab administered intravenously in ocnt1 gene knockout mice and their C57BL/6 controls. Stool, colon, and mesenteric lymph node samples were collected to evaluate differences in gut microbiota composition, histology, and T cell populations, respectively. Results Octn1 -/- influences the microbiota profile and is associated with a worse dysbiosis in mice with colitis. Infliximab treatment attenuates colitis-associated dysbiosis, with an increase of bacterial richness and evenness in both strains. In comparison with wild type, octn1-/- mice have milder disease and a higher baseline percentage of Treg, Tmemory, Th2 and Th17 cells. Conclusions Our data support the murine model to study OCTN1 genetic contribution to inflammatory bowel diseases. This could be the first step towards the recognition of this membrane transporter as a biomarker in inflammatory conditions and a predictor of response to therapies.

Memory T-cell enriched haploidentical transplantation with NK cell addback results in promising long-term outcomes: a phase II trial

BackgroundRelapse remains a challenge after transplantation in pediatric patients with hematological malignancies. Myeloablative regimens used for disease control are associated with acute and long-term adverse effects. We used a CD45RA-depleted haploidentical graft for adoptive transfer of memory T cells combined with NK-cell addback and hypothesized that maximizing the graft-versus-leukemia (GVL) effect might allow for reduction in intensity of conditioning regimen.MethodsIn this phase II clinical trial (NCT01807611), 72 patients with hematological malignancies (complete remission (CR)1: 25, ≥ CR2: 28, refractory disease: 19) received haploidentical CD34 + enriched and CD45RA-depleted hematopoietic progenitor cell grafts followed by NK-cell infusion. Conditioning included fludarabine, thiotepa, melphalan, cyclophosphamide, total lymphoid irradiation, and graft-versus-host disease (GVHD) prophylaxis consisted of a short-course sirolimus or mycophenolate mofetil without serotherapy.ResultsThe 3-year overall survival (OS) and event-free-survival (EFS) for patients in CR1 were 92% (95% CI:72–98) and 88% (95% CI: 67–96); ≥ CR2 were 81% (95% CI: 61–92) and 68% (95% CI: 47–82) and refractory disease were 32% (95% CI: 11–54) and 20% (95% CI: 6–40). The 3-year EFS for all patients in morphological CR was 77% (95% CI: 64–87) with no difference amongst recipients with or without minimal residual disease (P = 0.2992). Immune reconstitution was rapid, with mean CD3 and CD4 T-cell counts of 410/μL and 140/μL at day + 30. Cumulative incidence of acute GVHD and chronic GVHD was 36% and 26% but most patients with acute GVHD recovered rapidly with therapy. Lower rates of grade III-IV acute GVHD were observed with NK-cell alloreactive donors (P = 0.004), and higher rates of moderate/severe chronic GVHD occurred with maternal donors (P = 0.035).ConclusionThe combination of a CD45RA-depleted graft and NK-cell addback led to robust immune reconstitution maximizing the GVL effect and allowed for use of a submyeloablative, TBI-free conditioning regimen that was associated with excellent EFS resulting in promising long-term outcomes in this high-risk population.The trial is registered at ClinicalTrials.gov (NCT01807611).

Bone Marrow-Suppressive Treatment in Children Is Associated with Diminished IFN-γ Response from T Cells upon Polyclonal and Varicella Zoster Virus Peptide Stimulation.

Severe haematological diseases and lymphoid malignancies require bone marrow (BM)-suppressive treatments. Knowledge regarding the impact of BM-suppressive treatments on children's memory T cells is very limited. Memory T cells play a crucial role in defending against herpesviruses, which is particularly relevant in paediatric cancer care. We studied 53 children in total; 34 with cancer and 2 with severe haematological disorders, with some receiving BM-suppressive treatment with or without allogeneic-haematopoietic stem cell transplantation (allo-HSCT), alongside 17 healthy controls. We focused on peripheral blood proportions of memory T-cell subsets using flow cytometry and analysed cytokine-secreting T cells with a four-parameter FluoroSpot assay in response to T-cell mitogen and varicella zoster virus (VZV) peptides. Patients on BM-suppressive treatment showed increased clusters of differentiation (CD)4+ and CD8+ effector memory (TEM)/terminally differentiated effector (TEFF) T cells compared to the healthy controls. They also exhibited, amongst other things, when compared to the healthy controls, a reduced total number of cytokine-secreting cells, by means of interferon (IFN)-γ, interleukin (IL)-17A, IL-10, and IL-22, following mitogen activation. A diminished IFN-γ response among the children with BM-suppressive treatment was observed upon VZV-peptide stimulation, compared to the healthy children. Collectively, the findings herein indicate that the children who are undergoing or have finished BM-suppressive treatment display qualitative differences in their T-cell memory compartment, potentially increasing their susceptibility to severe viral infections and impacting their immunotherapy, which relies on the functional ability of autologous T cells.