RESUMO
ABSTRACT: Inotuzumab ozogamicin (InO) is an antibody-drug conjugate that delivers calicheamicin to CD22-expressing cells. In a retrospective cohort of InO-treated patients with B-cell acute lymphoblastic leukemia, we sought to understand the genomic determinants of the response and resistance to InO. Pre- and post-InO-treated patient samples were analyzed by whole genome, exome, and/or transcriptome sequencing. Acquired CD22 mutations were observed in 11% (3/27) of post-InO-relapsed tumor samples, but not in refractory samples (0/16). There were multiple CD22 mutations per sample and the mechanisms of CD22 escape included epitope loss (protein truncation and destabilization) and epitope alteration. Two CD22 mutant cases were post-InO hyper-mutators resulting from error-prone DNA damage repair (nonhomologous/alternative end-joining repair, or mismatch repair deficiency), suggesting that hypermutation drove escape from CD22-directed therapy. CD22-mutant relapses occurred after InO and subsequent hematopoietic stem cell transplantation (HSCT), suggesting that InO eliminated the predominant clones, leaving subclones with acquired CD22 mutations that conferred resistance to InO and subsequently expanded. Acquired loss-of-function mutations in TP53, ATM, and CDKN2A were observed, consistent with a compromise of the G1/S DNA damage checkpoint as a mechanism for evading InO-induced apoptosis. Genome-wide CRISPR/Cas9 screening of cell lines identified DNTT (terminal deoxynucleotidyl transferase) loss as a marker of InO resistance. In conclusion, genetic alterations modulating CD22 expression and DNA damage response influence InO efficacy. Our findings highlight the importance of defining the basis of CD22 escape and eradication of residual disease before HSCT. The identified mechanisms of escape from CD22-targeted therapy extend beyond antigen loss and provide opportunities to improve therapeutic approaches and overcome resistance. These trials were registered at www.ClinicalTrials.gov as NCT01134575, NCT01371630, and NCT03441061.
Assuntos
Resistencia a Medicamentos Antineoplásicos , Inotuzumab Ozogamicina , Leucemia-Linfoma Linfoblástico de Células Precursoras B , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico , Humanos , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/genética , Resistencia a Medicamentos Antineoplásicos/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patologia , Feminino , Mutação , Masculino , Antineoplásicos Imunológicos/uso terapêutico , Antineoplásicos Imunológicos/farmacologia , Adulto , Pessoa de Meia-Idade , Estudos Retrospectivos , AdolescenteRESUMO
While therapies targeting CD19 by antibodies, chimeric antigen receptor T cells (CAR-T), and T cell engagers have improved the response rates in B cell malignancies, the emergence of resistant cell populations with low CD19 expression can lead to relapsed disease. We developed an in vitro model of adaptive resistance facilitated by chronic exposure of leukemia cells to a CD19 immunotoxin. Single-cell RNA-Seq (scRNA-Seq) showed an increase in transcriptionally distinct CD19lo populations among resistant cells. Mass cytometry demonstrated that CD22 was also decreased in these CD19lo-resistant cells. An assay for transposase-accessible chromatin with sequencing (ATAC-Seq) showed decreased chromatin accessibility at promoters of both CD19 and CD22 in the resistant cell populations. Combined loss of both CD19 and CD22 antigens was validated in samples from pediatric and young adult patients with B cell acute lymphoblastic leukemia (B-ALL) that relapsed after CD19 CAR-T-targeted therapy. Functionally, resistant cells were characterized by slower growth and lower basal levels of MEK activation. CD19lo resistant cells exhibited preserved B cell receptor signaling and were more sensitive to both Bruton's tyrosine kinase (BTK) and MEK inhibition. These data demonstrate that resistance to CD19 immunotherapies can result in decreased expression of both CD19 and CD22 and can result in dependency on BTK pathways.
Assuntos
Antígenos CD19 , Leucemia-Linfoma Linfoblástico de Células Precursoras , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico , Criança , Humanos , Adulto Jovem , Tirosina Quinase da Agamaglobulinemia , Antígenos CD19/genética , Cromatina , Imunoterapia Adotiva , Quinases de Proteína Quinase Ativadas por Mitógeno , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Receptores de Antígenos Quiméricos , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/genéticaRESUMO
Triple-negative breast cancer (TNBC) accounts for 15-20% of all breast cancer cases. Due to the lack of expression of well-known molecular targets [estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2)], there is a need for more alternative treatment approaches in TNBC. Chimeric antigen receptor (CAR)-T cell-based immunotherapy treatment is one of the latest treatment technologies with outstanding therapeutic advances in the past decade, especially in the treatment of hematologic malignancies, but the therapeutic effects of CAR-T cells against solid tumors have not yet shown significant clinical benefits. Identification of highly specific CAR-T targets in solid tumors is also crucial for its successful treatment. CD22 is reported to be a multifunctional receptor that is mainly expressed on the surface of mature B-cells (lymphocytes) and is also highly expressed in most B-cell malignancies. This study aimed to investigate the expression of CD22 in TNBC. Bioinformatic analysis was performed to evaluate the expression of CD22 in breast carcinoma and normal tissues. RNA-seq data of normal and breast carcinoma patients were downloaded from The Cancer Genome Atlas (TCGA), and differential gene expression was performed using R language. Additionally, online bioinformatics web tools (GEPIA and TNM plot) were used to evaluate the expression of CD22 in breast carcinoma and normal tissues. Western blot (WB) analysis and immunofluorescence (IF) were performed to characterize the expression of CD22 in TNBC cell lines. Immunohistochemical (IHC) staining was performed on tumor specimens from 97 TNBC patients for CD22 expression. Moreover, statistical analysis was performed to analyze the association of clinical pathological parameters with CD22 expression. Correlation analysis between overall survival data of TNBC patients and CD22 expression was also performed. Differential gene expression analysis of TCGA data revealed that CD22 is among the upregulated differentially expressed genes (DEGs) with high expression in breast cancer, as compared to normal breast tissues. WB and IF analysis revealed high expression of CD22 in TNBC cell lines. IHC results also showed that approximately 62.89% (61/97) of TNBC specimens were stained positive for CD22. Cell membrane expression of CD22 was evident in 23.71% (23/97) of TNBC specimens, and 39.18% (38/97) of TNBC specimens showed cytoplasmic/membrane expression, while 37.11% (36/97) specimens were negative for CD22. Furthermore, significant associations were found between the size of tumors in TNBC patients and CD22 expression, which unveils its potential as a prognostic biomarker. No significant correlation was found between the overall survival of TNBC patients and CD22 expression. In conclusion, we demonstrated for the first time that CD22 is highly expressed in TNBC. Based on our findings, we anticipated that CD22 could be used as a prognostic biomarker in TNBC, and it might be a potential CAR-T target in TNBC for whom few therapeutic options exist. However, more large-scale studies and clinical trials will ensure its potential usefulness as a CAR-T target in TNBC.
Assuntos
Receptores de Antígenos Quiméricos , Neoplasias de Mama Triplo Negativas , Humanos , Neoplasias de Mama Triplo Negativas/terapia , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Receptores de Antígenos Quiméricos/uso terapêutico , Prognóstico , Imunoterapia Adotiva/métodos , Biologia Computacional , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/genéticaRESUMO
Despite impressive progress, a significant portion of patients still experience primary or secondary resistance to chimeric antigen receptor (CAR) T-cell immunotherapy for relapsed/refractory diffuse large B-cell lymphoma (r/r DLBCL). The mechanism of primary resistance involves T-cell extrinsic and intrinsic dysfunction. In the present study, a total of 135 patients of DLBCL treated with murine CD19/CD22 cocktail CAR T-therapy were assessed retrospectively. Based on four criteria (maximal expansion of the transgene/CAR-positive T-cell levels post-infusion [Cmax], initial persistence of the transgene by the CAR transgene level at +3 months [Tlast], CD19+ B-cell levels [B-cell recovery], and the initial response to CAR T-cell therapy), 48 patients were included in the research and divided into two groups (a T-normal group [n=22] and a T-defect [n=26] group). According to univariate and multivariate regression analyses, higher lactate dehydrogenase (LDH) levels before leukapheresis (hazard ratio (HR) = 1.922; p = 0.045) and lower cytokine release syndrome (CRS) grade after CAR T-cell infusion (HR = 0.150; p = 0.026) were independent risk factors of T-cell dysfunction. Moreover, using whole-exon sequencing, we found that germline variants in 47 genes were significantly enriched in the T-defect group compared to the T-normal group (96% vs. 41%; p<0.0001), these genes consisted of CAR structure genes (n=3), T-cell signal 1 to signal 3 genes (n=13), T cell immune regulation- and checkpoint-related genes (n=9), cytokine- and chemokine-related genes (n=13), and T-cell metabolism-related genes (n=9). Heterozygous germline UNC13D mutations had the highest intergroup differences (26.9% vs. 0%; p=0.008). Compound heterozygous CX3CR1I249/M280 variants, referred to as pathogenic and risk factors according to the ClinVar database, were enriched in the T-defect group (3 of 26). In summary, the clinical characteristics and T-cell immunodeficiency genetic features may help explain the underlying mechanism of treatment primary resistance and provide novel insights into CAR T-cell immunotherapy.
Assuntos
Linfoma Difuso de Grandes Células B , Receptores de Antígenos Quiméricos , Animais , Antígenos CD19 , Humanos , Imunoterapia Adotiva/efeitos adversos , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/terapia , Proteínas de Membrana , Camundongos , Fatores R , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/uso terapêutico , Estudos Retrospectivos , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/genética , Linfócitos TRESUMO
The protein tyrosine phosphatase CD45 plays a crucial role in B cell antigen receptor (BCR) signaling by activating Src family kinases. Cd45-/- mice show altered B cell development and a phenotype likely due to reduced steady-state signaling; however, Cd45-/- B cells show relatively normal BCR ligation-induced signaling. In our investigation of how BCR signaling was restored in Cd45-/- cells, we found that the coreceptor CD22 switched from an inhibitory to a stimulatory function in these cells. We disrupted the ability of CD22 to interact with its ligands in Cd45-/- B cells by generating Cd45-/-St6galI-/- mice, which cannot synthesize the glycan ligand of CD22, or by treating Cd45-/- B cells in vitro with the sialoside GSC718, which inhibits ligand binding to CD22. BCR ligation-induced signaling was reduced by ST6GalI deficiency, but not by GSC718 treatment, suggesting that CD22 restored BCR ligation-induced signaling in Cd45-/- mature B cells by altering cellular phenotypes during development. CD22 was required for the increase in the surface amount of IgM-BCR on Cd45-/- B cells, which augmented signaling. Because B cell survival depends on steady-state BCR signaling, IgM-BCR abundance was likely increased by the selective survival of IgM-BCRhi Cd45-/- B cells because of CD22-mediated signaling under conditions of substantially reduced steady-state signaling. Because the amount of surface IgM-BCR is increased on B cells from patients with other BCR signaling deficiencies, including X-linked agammaglobulinemia, our findings suggest that CD22 may contribute to the partial restoration of B cell function in these patients.
Assuntos
Linfócitos B , Receptores de Antígenos de Linfócitos B , Animais , Linfócitos B/metabolismo , Antígenos Comuns de Leucócito , Ativação Linfocitária , Camundongos , Receptores de Antígenos de Linfócitos B/metabolismo , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/genética , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/metabolismo , Transdução de Sinais , Quinases da Família src/metabolismoRESUMO
Downregulation of surface epitopes causes postimmunotherapy relapses in B-lymphoblastic leukemia (B-ALL). Here we demonstrate that mRNA encoding CD22 undergoes aberrant splicing in B-ALL. We describe the plasma membrane-bound CD22 Δex5-6 splice isoform, which is resistant to chimeric antigen receptor (CAR) T cells targeting the third immunoglobulin-like domain of CD22. We also describe splice variants skipping the AUG-containing exon 2 and failing to produce any identifiable protein, thereby defining an event that is rate limiting for epitope presentation. Indeed, forcing exon 2 skipping with morpholino oligonucleotides reduced CD22 protein expression and conferred resistance to the CD22-directed antibody-drug conjugate inotuzumab ozogamicin in vitro. Furthermore, among inotuzumab-treated pediatric patients with B-ALL, we identified one nonresponder in whose leukemic blasts Δex2 isoforms comprised the majority of CD22 transcripts. In a second patient, a sharp reduction in CD22 protein levels during relapse was driven entirely by increased CD22 exon 2 skipping. Thus, dysregulated CD22 splicing is a major mechanism of epitope downregulation and ensuing resistance to immunotherapy. SIGNIFICANCE: The mechanism(s) underlying downregulation of surface CD22 following CD22-directed immunotherapy remains underexplored. Our biochemical and correlative studies demonstrate that in B-ALL, CD22 expression levels are controlled by inclusion/skipping of CD22 exon 2. Thus, aberrant splicing of CD22 is an important driver/biomarker of de novo and acquired resistance to CD22-directed immunotherapies. See related commentary by Bourcier and Abdel-Wahab, p. 87. This article is highlighted in the In This Issue feature, p. 85.
Assuntos
Deriva e Deslocamento Antigênicos , Leucemia-Linfoma Linfoblástico de Células Precursoras , Criança , Epitopos/uso terapêutico , Humanos , Imunoterapia , Inotuzumab Ozogamicina , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/genéticaRESUMO
Despite high remission rates following chimeric antigen receptor T cell (CAR-T) cell therapy in B-cell acute lymphoblastic leukemia (B-ALL), relapse due to loss of the targeted antigen is increasingly recognized as a mechanism of immune escape. We hypothesized that simultaneous targeting of CD19 and CD22 may improve the CAR-T effect. The in vitro and in vivo leukemia model was established, and the anti-tumor effects of BiCAR-T, CD19 CAR-T, CD22 CAR-T, and LoopCAR6 cells were observed. We found that the BiCAR-T cells showed significant cytotoxicity in vitro and in vivo. The CD19/CD22 bivalent CAR provides an opportunity to test whether simultaneous targeting may reduce the risk of antigen loss.
Assuntos
Antígenos CD19/imunologia , Imunoterapia Adotiva/métodos , Leucemia Experimental/terapia , Receptores de Antígenos Quiméricos/imunologia , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/imunologia , Animais , Antígenos CD19/genética , Feminino , Humanos , Células K562 , Lentivirus/genética , Camundongos , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/genéticaRESUMO
CD19-directed chimeric antigen receptor (CAR) T cells have yielded impressive response rates in refractory/relapse B cell acute lymphoblastic leukemia (B-ALL); however, most patients ultimately relapse due to poor CAR T cell persistence or resistance of either CD19+ or CD19- B-ALL clones. CD22 is a pan-B marker whose expression is maintained in both CD19+ and CD19- relapses. CD22-CAR T cells have been clinically used in B-ALL patients, although relapse also occurs. T cells engineered with a tandem CAR (Tan-CAR) containing in a single construct both CD19 and CD22 scFvs may be advantageous in achieving higher remission rates and/or preventing antigen loss. We have generated and functionally validated using cutting-edge assays a 4-1BB-based CD22/CD19 Tan-CAR using in-house-developed novel CD19 and CD22 scFvs. Tan-CAR-expressing T cells showed similar in vitro expansion to CD19-CAR T cells with no increase in tonic signaling. CRISPR-Cas9-edited B-ALL cells confirmed the bispecificity of the Tan-CAR. Tan-CAR was as efficient as CD19-CAR in vitro and in vivo using B-ALL cell lines, patient samples, and patient-derived xenografts (PDXs). Strikingly, the robust antileukemic activity of the Tan-CAR was slightly more effective in controlling the disease in long-term follow-up PDX models. This Tan-CAR construct warrants a clinical appraisal to test whether simultaneous targeting of CD19 and CD22 enhances leukemia eradication and reduces/delays relapse rates and antigen loss.
Assuntos
Receptores de Antígenos Quiméricos , Antígenos CD19 , Linfócitos B , Humanos , Imunoterapia Adotiva , Receptores de Antígenos Quiméricos/metabolismo , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/genética , Linfócitos TRESUMO
Objectives: At present, reinfusions of chimeric antigen receptor (CAR)-T cell have exhibited limited efficacy, while their efficacy on extramedullary relapse remains to be further elucidated in B-cell acute lymphoblastic leukemia (B-ALL). Although combination with IL-15 demonstrated the potential to enhance antitumor activity of CAR-T, the efficacy of this approach remains to be validated clinically. Methods: We reported a patient with B-ALL with extramedullary relapse after allogeneic stem cell transplantation and who was resistant to chemotherapy and radiotherapy. In total, he received four treatments with CAR-T cells repeatedly under the status of disease progression. Results: First, the patient received autologous murine CAR19-CD28-CD3ζ-T cells and achieved full resolution of extramedullary leukemia lasting 8 months. After systemic disease relapse, he received autologous humanized CAR22-41BB-CD3ζ-tEGFR-T cells and achieved complete remission (CR) with incomplete blood count recovery (CRi) with minimal residual disease (MRD) negativity in the bone marrow and shrinkage of extramedullary leukemia. Over 2 months later, he experienced a relapse of the systemic disease and he received autologous murine CAR19-41BB-CD3ζ-mIL15-T cells and achieved CRiMRD- lasting 5 months with the strongest expansion and persistence of CAR. Finally, on relapse of CD19- medullary disease, he received allogeneic humanized CAR22-41BB-CD3ζ-tEGFR-T cells but only achieved a transient decrease in the number of blasts. No CAR-T-cell-related encephalopathy syndrome was observed, and all side effects were manageable. Conclusion: Our report hints the feasibility and safety of CD19 CAR-T cell expressing membrane-bound IL-15 for patient with B-ALL even if relapsed after multiple CAR-T-cell therapies.
Assuntos
Antígenos CD19/genética , Terapia Genética , Imunoterapia Adotiva , Interleucina-15/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/terapia , Receptores de Antígenos Quiméricos/genética , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/genética , Linfócitos T/transplante , Adulto , Antígenos CD19/metabolismo , Progressão da Doença , Humanos , Interleucina-15/metabolismo , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/imunologia , Leucemia-Linfoma Linfoblástico de Células Precursoras B/metabolismo , Receptores de Antígenos Quiméricos/metabolismo , Retratamento , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/metabolismo , Linfócitos T/imunologia , Linfócitos T/metabolismo , Fatores de Tempo , Resultado do TratamentoRESUMO
Targeted immunotherapies have greatly changed treatment of patients with B cell malignancies. To further enhance immunotherapies, research increasingly focuses on the tumor microenvironment (TME), which differs considerably by organ site. However, immunocompetent mouse models of disease to study immunotherapies targeting human molecules within organ-specific TME are surprisingly rare. We developed a myc-driven, primary murine lymphoma model expressing a human-mouse chimeric CD22 (h/mCD22). Stable engraftment of three distinct h/mCD22+ lymphoma was established after subcutaneous and systemic injection. However, only systemic lymphoma showed immune infiltration that reflected human disease. In this model, myeloid cells supported lymphoma growth and showed a phenotype of myeloid-derived suppressor cells. The human CD22-targeted immunotoxin Moxetumomab was highly active against h/mCD22+ lymphoma and similarly reduced infiltration of bone marrow and spleen of all three models up to 90-fold while efficacy against lymphoma in lymph nodes varied substantially, highlighting relevance of organ-specific TME. As in human aggressive lymphoma, anti-PD-L1 as monotherapy was not efficient. However, anti-PD-L1 enhanced efficacy of Moxetumomab suggesting potential for future clinical application. The novel model system of h/mCD22+ lymphoma provides a unique platform to test targeted immunotherapies and may be amenable for other human B cell targets such as CD19 and CD20.
Assuntos
Imunoterapia , Linfoma , Proteínas de Neoplasias , Neoplasias Experimentais , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico , Microambiente Tumoral , Animais , Humanos , Linfoma/genética , Linfoma/imunologia , Linfoma/terapia , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Camundongos Transgênicos , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/imunologia , Neoplasias Experimentais/genética , Neoplasias Experimentais/imunologia , Neoplasias Experimentais/terapia , Especificidade de Órgãos/genética , Especificidade de Órgãos/imunologia , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/genética , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/imunologia , Microambiente Tumoral/genética , Microambiente Tumoral/imunologiaRESUMO
Chimeric antigen receptor (CAR) T cells targeting CD19 or CD22 have shown remarkable activity in B cell acute lymphoblastic leukemia (B-ALL). The major cause of treatment failure is antigen downregulation or loss. Dual antigen targeting could potentially prevent this, but the clinical safety and efficacy of CAR T cells targeting both CD19 and CD22 remain unclear. We conducted a phase 1 trial in pediatric and young adult patients with relapsed or refractory B-ALL (n = 15) to test AUTO3, autologous transduced T cells expressing both anti-CD19 and anti-CD22 CARs (AMELIA trial, EUDRA CT 2016-004680-39). The primary endpoints were the incidence of grade 3-5 toxicity in the dose-limiting toxicity period and the frequency of dose-limiting toxicities. Secondary endpoints included the rate of morphological remission (complete response or complete response with incomplete bone marrow recovery) with minimal residual disease-negative response, as well as the frequency and severity of adverse events, expansion and persistence of AUTO3, duration of B cell aplasia, and overall and event-free survival. The study endpoints were met. AUTO3 showed a favorable safety profile, with no dose-limiting toxicities or cases of AUTO3-related severe cytokine release syndrome or neurotoxicity reported. At 1 month after treatment the remission rate (that is, complete response or complete response with incomplete bone marrow recovery) was 86% (13 of 15 patients). The 1 year overall and event-free survival rates were 60% and 32%, respectively. Relapses were probably due to limited long-term AUTO3 persistence. Strategies to improve CAR T cell persistence are needed to fully realize the potential of dual targeting CAR T cell therapy in B-ALL.
Assuntos
Antígenos CD19/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/terapia , Receptores de Antígenos Quiméricos/administração & dosagem , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/genética , Adolescente , Adulto , Antígenos CD19/imunologia , Criança , Pré-Escolar , Feminino , Humanos , Imunoterapia/efeitos adversos , Imunoterapia/tendências , Imunoterapia Adotiva/efeitos adversos , Imunoterapia Adotiva/tendências , Lactente , Masculino , Pediatria , Intervalo Livre de Progressão , Receptores de Antígenos Quiméricos/imunologia , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/imunologia , Adulto JovemRESUMO
Microglia, the innate immune cells of the brain, are essential for maintaining homeostasis by their ramified, highly motile processes and for orchestrating the immune response to pathological stimuli. They are implicated in several neurodegenerative diseases like Alzheimer's and Parkinson's disease. One commonality of these diseases is their strong correlation with aging as the highest risk factor and studying age-related alterations in microglia physiology and associated signaling mechanism is indispensable for a better understanding of age-related pathomechanisms. CD22 has been identified as a modifier of microglia phagocytosis in a recent study, but not much is known about the function of CD22 in microglia. Here we show that CD22 surface levels are upregulated in aged versus adult microglia. Furthermore, in the amyloid mouse model PS2APP, Aß-containing microglia also exhibit increased CD22 signal. To assess the impact of CD22 blockage on microglia morphology and dynamics, we have established a protocol to image microglia process motility in acutely prepared brain slices from CX3CR1-GFP reporter mice. We observed a significant reduction of microglial ramification and surveillance capacity in brain slices from aged versus adult mice. The age-related decrease in surveillance can be restored by antibody-mediated CD22 blockage in aged mice, whereas surveillance in adult mice is not affected by CD22 inhibition. Moreover to complement the results obtained in mice, we show that human iPSC-derived macrophages exhibit an increased phagocytic capacity upon CD22 blockage. Downstream analysis of antibody-mediated CD22 inhibition revealed an influence on BMP and TGFß associated gene networks. Our results demonstrate CD22 as a broad age-associated modulator of microglia functionality with potential implications for neurodegenerative disorders.
Assuntos
Envelhecimento/fisiologia , Encéfalo/citologia , Microglia/efeitos dos fármacos , Fagocitose/efeitos dos fármacos , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/antagonistas & inibidores , Envelhecimento/efeitos dos fármacos , Envelhecimento/genética , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/fisiologia , Contagem de Células , Modelos Animais de Doenças , Humanos , Macrófagos/metabolismo , Masculino , Camundongos , Microglia/citologia , Fagocitose/genética , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/genética , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/metabolismo , Transdução de SinaisRESUMO
The integrin α4ß7 selectively regulates lymphocyte trafficking and adhesion in the gut and gut-associated lymphoid tissue (GALT). Here, we describe unexpected involvement of the tyrosine phosphatase Shp1 and the B cell lectin CD22 (Siglec-2) in the regulation of α4ß7 surface expression and gut immunity. Shp1 selectively inhibited ß7 endocytosis, enhancing surface α4ß7 display and lymphocyte homing to GALT. In B cells, CD22 associated in a sialic acid-dependent manner with integrin ß7 on the cell surface to target intracellular Shp1 to ß7. Shp1 restrained plasma membrane ß7 phosphorylation and inhibited ß7 endocytosis without affecting ß1 integrin. B cells with reduced Shp1 activity, lacking CD22 or expressing CD22 with mutated Shp1-binding or carbohydrate-binding domains displayed parallel reductions in surface α4ß7 and in homing to GALT. Consistent with the specialized role of α4ß7 in intestinal immunity, CD22 deficiency selectively inhibited intestinal antibody and pathogen responses.
Assuntos
Linfócitos B/enzimologia , Imunidade nas Mucosas , Cadeias beta de Integrinas/metabolismo , Integrinas/metabolismo , Mucosa Intestinal/enzimologia , Proteína Tirosina Fosfatase não Receptora Tipo 6/metabolismo , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/metabolismo , Animais , Linfócitos B/imunologia , Linfócitos B/virologia , Quimiotaxia de Leucócito , Modelos Animais de Doenças , Endocitose , Feminino , Cadeias beta de Integrinas/imunologia , Integrinas/imunologia , Mucosa Intestinal/imunologia , Mucosa Intestinal/virologia , Masculino , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fosforilação , Proteína Tirosina Fosfatase não Receptora Tipo 6/deficiência , Proteína Tirosina Fosfatase não Receptora Tipo 6/genética , Rotavirus/imunologia , Rotavirus/patogenicidade , Infecções por Rotavirus/genética , Infecções por Rotavirus/imunologia , Infecções por Rotavirus/metabolismo , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/deficiência , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/genética , Transdução de Sinais , Técnicas de Cultura de TecidosAssuntos
Resistência a Medicamentos/genética , Inotuzumab Ozogamicina/administração & dosagem , Mutação , Leucemia-Linfoma Linfoblástico de Células Precursoras B , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/genética , Adolescente , Humanos , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genéticaRESUMO
Streptococcus pneumoniae is a major human pathogen, causing pneumonia and sepsis. Genetic components strongly influence host responses to pneumococcal infections, but the responsible loci are unknown. We have previously identified a locus on mouse chromosome 7 from a susceptible mouse strain, CBA/Ca, to be crucial for pneumococcal infection. Here we identify a responsible gene, Cd22, which carries a point mutation in the CBA/Ca strain, leading to loss of CD22 on B cells. CBA/Ca mice and gene-targeted CD22-deficient mice on a C57BL/6 background are both similarly susceptible to pneumococcal infection, as shown by bacterial replication in the lungs, high bacteremia and early death. After bacterial infections, CD22-deficient mice had strongly reduced B cell populations in the lung, including GM-CSF producing, IgM secreting innate response activator B cells, which are crucial for protection. This study provides striking evidence that CD22 is crucial for protection during invasive pneumococcal disease.
Assuntos
Linfócitos B/imunologia , Infecções Pneumocócicas/imunologia , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/imunologia , Animais , Linfócitos B/microbiologia , Bacteriemia/genética , Bacteriemia/imunologia , Bacteriemia/microbiologia , Feminino , Interações Hospedeiro-Patógeno , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Infecções Pneumocócicas/genética , Infecções Pneumocócicas/metabolismo , Pneumonia Pneumocócica/genética , Pneumonia Pneumocócica/imunologia , Pneumonia Pneumocócica/metabolismo , Pneumonia Pneumocócica/microbiologia , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/deficiência , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/genética , Streptococcus pneumoniae/patogenicidadeRESUMO
Single-chain variable fragment (scFv) antibodies are fusion proteins of the variable regions of the heavy and light chains of immunoglobulins connected with a short linker peptide. They possess unique and superior features compared to whole antibodies for immunotherapy of various carcinomas, including hematologic B-cell malignancies. In the presented study we obtained efficient production of the recombinant anti-CD22 scFv in Escherichia coli expression system. The active recombinant protein was successfully recovered from inclusion bodies. Assays were performed to assess the in vitro targeting properties and specificity of the obtained anti-CD22 scFv antibody in the CD22 positive and negative lymphoma cell lines.
Assuntos
Imunoconjugados/química , Linfócitos/metabolismo , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/genética , Anticorpos de Cadeia Única/genética , Linhagem Celular Tumoral , Clonagem Molecular , Escherichia coli/genética , Escherichia coli/metabolismo , Fluoresceína-5-Isotiocianato/química , Corantes Fluorescentes/química , Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Humanos , Imunoconjugados/metabolismo , Corpos de Inclusão/química , Células K562 , Linfócitos/patologia , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/química , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/metabolismo , Anticorpos de Cadeia Única/química , Anticorpos de Cadeia Única/metabolismoRESUMO
BACKGROUND: Systemic sclerosis (SSc) is a systemic autoimmune disease that is characterized by excessive fibrosis. CD22 and CD72 are B cell-specific cell surface molecules that negatively regulate B cell function. OBJECTIVE: The aim of the present study was to investigate the roles of CD22 and CD72 in a murine scleroderma model. METHODS: The experimental fibrosis model was generated by subcutaneous injection of bleomycin or hypochlorous acid (HOCL) into wild-type (WT), CD22-deficient (CD22-/-), CD72-deficient (CD72-/-) and CD22 and CD72 double-deficient (CD22-/-/CD72-/-) mice. We histologically assessed skin fibrosis and inflammatory cell infiltration. Cytokine and chemokine expression levels were measured by real-time polymerase chain reaction. RESULTS: The severity of fibrosis in the skin and lung was significantly less in CD22-/-, CD72-/-, and CD22-/-/CD72-/- mice than in WT mice in the bleomycin-induced model. In the skin of bleomycin-treated mice, the numbers of CD3+ T cells, CD8+ T cells, and F4/80+ macrophages were significantly lower in CD22-/-, CD72-/-, and CD22-/-/CD72-/- mice than in WT mice. The expression levels of mRNAs for IL-6, TNF-α, TGF-ß, CTGF, IL-1ß, IL-13, CXCL2, and ICAM-1 were significantly lower in CD22-/-, CD72-/-, and CD22-/-/CD72-/- mice than in WT mice. In the HOCL-induced model, both skin and lung fibrosis were ameliorated in CD22-/-, CD72-/- and CD22-/-/CD72-/- mice compared to WT mice. CONCLUSION: These results indicate that CD22 and CD72 likely play crucial roles in skin and lung fibrosis. Moreover, the inhibition of CD22 and CD72 function has potential as a therapeutic approach to SSc.
Assuntos
Antígenos CD/metabolismo , Antígenos de Diferenciação de Linfócitos B/metabolismo , Pulmão/patologia , Escleroderma Sistêmico/patologia , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/metabolismo , Pele/patologia , Animais , Antígenos CD/genética , Antígenos de Diferenciação de Linfócitos B/genética , Bleomicina/toxicidade , Modelos Animais de Doenças , Humanos , Ácido Hipocloroso/toxicidade , Pulmão/efeitos dos fármacos , Camundongos , Camundongos Knockout , Escleroderma Sistêmico/induzido quimicamente , Escleroderma Sistêmico/diagnóstico , Índice de Gravidade de Doença , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/genética , Pele/efeitos dos fármacosRESUMO
BACKGROUND: Local type III hypersensitivity reactions are acute inflammatory events induced by immune complex (IC) deposition. CD22 and CD72 are B cell-specific cell surface molecules that negatively regulate B cell function. OBJECTIVE: To elucidate the roles of CD22 and CD72 in the development of IgG-mediated type III hypersensitivity reactions. METHOD: The reverse Arthus reaction model in the skin was induced in mice lacking CD22 (CD22-/-), CD72 (CD72-/-), and both of them (CD22-/-/CD72-/-). Edema at 4h and hemorrhage at 8h after IC challenge were evaluated. Inflammatory cell infiltration and cytokine and chemokine expression were also examined. RESULTS: Edema and hemorrhage were significantly reduced in CD22-/-/CD72-/- mice compared with wild-type mice. The loss of both membrane proteins resulted in a greater decrease in edema at 4h, but not hemorrhage at 8h, than the loss of each protein alone. Infiltration of neutrophils, macrophages, and T cells, and the expression of TNF-α, IL-6, MIP-1α, and CCR5 mRNA were also diminished in the knockout mice compared to wild-type mice, and most significantly reduced in CD22-/-/CD72-/- mice. Regulatory T (Treg) cells in the spleen were significantly increased in all knockout mice at 4h. Significant differences in the severity of edema and hemorrhage between wild-type and knockout mice were lost when Treg cells were depleted in the knockout mice. CONCLUSION: These results demonstrate that CD22 and CD72 expression contribute to the development of the reverse Arthus reaction model and CD22 and CD72 might be therapeutic targets for human IC-mediated diseases.
Assuntos
Antígenos CD/imunologia , Antígenos de Diferenciação de Linfócitos B/imunologia , Reação de Arthus/imunologia , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/imunologia , Pele/imunologia , Animais , Complexo Antígeno-Anticorpo/administração & dosagem , Complexo Antígeno-Anticorpo/imunologia , Antígenos CD/genética , Antígenos de Diferenciação de Linfócitos B/genética , Reação de Arthus/patologia , Biópsia , Injeções Intradérmicas , Camundongos , Camundongos Knockout , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/genética , Pele/patologiaRESUMO
Microglia maintain homeostasis in the central nervous system through phagocytic clearance of protein aggregates and cellular debris. This function deteriorates during ageing and neurodegenerative disease, concomitant with cognitive decline. However, the mechanisms of impaired microglial homeostatic function and the cognitive effects of restoring this function remain unknown. We combined CRISPR-Cas9 knockout screens with RNA sequencing analysis to discover age-related genetic modifiers of microglial phagocytosis. These screens identified CD22, a canonical B cell receptor, as a negative regulator of phagocytosis that is upregulated on aged microglia. CD22 mediates the anti-phagocytic effect of α2,6-linked sialic acid, and inhibition of CD22 promotes the clearance of myelin debris, amyloid-ß oligomers and α-synuclein fibrils in vivo. Long-term central nervous system delivery of an antibody that blocks CD22 function reprograms microglia towards a homeostatic transcriptional state and improves cognitive function in aged mice. These findings elucidate a mechanism of age-related microglial impairment and a strategy to restore homeostasis in the ageing brain.
Assuntos
Envelhecimento/fisiologia , Encéfalo/citologia , Homeostase/efeitos dos fármacos , Microglia/efeitos dos fármacos , Ácido N-Acetilneuramínico/farmacologia , Fagocitose/efeitos dos fármacos , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/antagonistas & inibidores , Envelhecimento/efeitos dos fármacos , Envelhecimento/genética , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/fisiologia , Proteína 9 Associada à CRISPR/metabolismo , Sistemas CRISPR-Cas/genética , Cognição/efeitos dos fármacos , Cognição/fisiologia , Feminino , Homeostase/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microglia/citologia , Ácido N-Acetilneuramínico/química , Fagocitose/genética , Análise de Sequência de RNA , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/genética , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/metabolismoRESUMO
The organization and clustering of cell surface proteins plays a critical role in controlling receptor signaling; however, the biophysical mechanisms regulating these parameters are not well understood. Elucidating these mechanisms is highly significant to our understanding of immune function in health and disease, given the importance of B cell receptor (BCR) signaling in directing B cells to produce antibodies for the clearance of pathogens, and the potential deleterious effects of dysregulated BCR signaling, such as in B cell malignancies or autoimmune disease. One of main inhibitory co-receptors on B cells is CD22, a sialic-acid binding protein, which interacts homotypically with other sialylated CD22 molecules, as well as heterotypically with IgM and CD45. Although the importance of CD22 in attenuating BCR signaling is well established, we still do not fully understand what mediates CD22 organization and association to BCRs. CD22 is highly glycosylated, containing 12 N-linked glycosylation sites on its extracellular domain, the function of which remain to be resolved. We were interested in how these glycosylation sites mediate homotypic vs. heterotypic interactions. To this end, we mutated five out of the six N-linked glycosylation residues on CD22 localized closest to the sialic acid binding site. Glycan site N101 was not mutated as this resulted in lack of CD22 expression. We used dual-color super-resolution imaging to investigate the impact of altered glycosylation of CD22 on the nanoscale organization of CD22 and its association with BCR. We show that mutation of these five glycosylation sites increased the clustering tendency of CD22 and resulted in higher density CD22 nanoclusters. Consistent with these findings of altered CD22 organization, we found that mutation of N-glycan sites attenuated CD22 phosphorylation upon BCR stimulation, and consequently, increased BCR signaling. Importantly, we identified that these sites may be ligands for the soluble secreted lectin, galectin-9, and are necessary for galectin-9 mediated inhibition of BCR signaling. Taken together, these findings implicate N-linked glycosylation in the organization and function of CD22, likely through regulating heterotypic interactions between CD22 and its binding partners.