Analysis of clinicopathological and molecular abnormalities of angioimmunoblastic T-cell lymphoma / 北京大学学报(医学版)

OBJECTIVE@#To analyze the clinicopathological features, molecular changes and prognostic factors in angioimmunoblastic T-cell lymphoma (AITL).@*METHODS@#Sixty-one cases AITL diagnosed by Department of Pathology of Peking University Cancer Hospital were collected with their clinical data. Morphologically, they were classified as typeⅠ[lymphoid tissue reactive hyperplasia (LRH) like]; typeⅡ[marginal zone lymphoma(MZL)like] and type Ⅲ [peripheral T-cell lymphoma, not specified (PTCL-NOS) like]. Immunohistochemical staining was used to evaluate the presence of follicular helper T-cell (TFH) phenotype, proliferation of extra germinal center (GC) follicular dendritic cells (FDCs), presence of Hodgkin and Reed-Sternberg (HRS)-like cells and large B transformation. The density of Epstein-Barr virus (EBV) + cells was counted with slides stained by Epstein-Barr virus encoded RNA (EBER) in situ hybridization on high power field (HPF). T-cell receptor / immunoglobulin gene (TCR/IG) clonality and targeted exome sequencing (TES) test were performed when necessary. SPSS 22.0 software was used for statistical analysis.@*RESULTS@#Morphological subtype (%): 11.4% (7/61) cases were classified as type Ⅰ; 50.8% (31/61) as type Ⅱ; 37.8% (23/61) as type Ⅲ. 83.6% (51/61) cases showed classical TFH immunophenotype. With variable extra-GC FDC meshwork proliferation (median 20.0%); 23.0% (14/61) had HRS-like cells; 11.5% (7/61) with large B transformation. 42.6% (26/61) of cases with high counts of EBV. 57.9% (11/19) TCR+/IG-, 26.3% (5/19) TCR+/IG+, 10.5% (2/19) were TCR－/IG－, and 5.3% (1/19) TCR－/IG+. Mutation frequencies by TES were 66.7% (20/30) for RHOA, 23.3% (7/30) for IDH2 mutation, 80.0% (24/30) for TET2 mutation, and 33.3% (10/30) DNMT3A mutation. Integrated analysis divided into four groups: (1) IDH2 and RHOA co-mutation group (7 cases): 6 cases were type Ⅱ, 1 case was type Ⅲ; all with typical TFH phenotype; HRS-like cells and large B transformation were not found; (2) RHOA single mutation group (13 cases): 1 case was type Ⅰ, 6 cases were type Ⅱ, 6 cases were type Ⅲ; 5 cases without typical TFH phenotype; 6 cases had HRS-like cells, and 2 cases with large B transformation. Atypically, 1 case showed TCR－/IG－, 1 case with TCR－/IG+, and 1 case with TCR+/IG+; (3) TET2 and/or DNMT3A mutation alone group (7 cases): 3 cases were type Ⅱ, 4 cases were type Ⅲ, all cases were found with typical TFH phenotype; 2 cases had HRS-like cells, 2 cases with large B transformation, and atypically; (4) non-mutation group (3 cases), all were type Ⅱ, with typical TFH phenotype, with significant extra-GC FDC proliferation, without HRS-like cells and large B transformation. Atypically, 1 case was TCR－/IG－. Univariate analysis confirmed that higher density of EBV positive cell was independent adverse prognostic factors for both overall survival (OS) and progression free survival(PFS), (P=0.017 and P=0.046).@*CONCLUSION@#Pathological diagnoses of ALTL cases with HRS-like cells, large B transformation or type Ⅰ are difficult. Although TCR/IG gene rearrangement test is helpful but still with limitation. TES involving RHOA, IDH2, TET2, DNMT3A can robustly assist in the differential diagnosis of those difficult cases. Higher density of EBV positive cells counts in tumor tissue might be an indicator for poor survival.

Prediction of superantigen active sites and clonal expression of staphylococcal enterotoxin-like W / 中华流行病学杂志

Objective: The docking and superantigen activity sites of staphylococcal enterotoxin-like W (SElW) and T cell receptor (TCR) were predicted, and its SElW was cloned, expressed and purified. Methods: AlphaFold was used to predict the 3D structure of SElW protein monomers, and the protein models were evaluated with the help of the SAVES online server from ERRAT, Ramachandran plot, and Verify_3D. The ZDOCK server simulates the docking conformation of SElW and TCR, and the amino acid sequences of SElW and other serotype enterotoxins were aligned. The primers were designed to amplify selw, and the fragment was recombined into the pMD18-T vector and sequenced. Then recombinant plasmid pMD18-T was digested with BamHⅠand Hind Ⅲ. The target fragment was recombined into the expression plasmid pET-28a(+). After identification of the recombinant plasmid, the protein expression was induced by isopropyl-beta-D- thiogalactopyranoside. The SElW expressed in the supernatant was purified by affinity chromatography and quantified by the BCA method. Results: The predicted three-dimensional structure showed that the SElW protein was composed of two domains, the amino-terminal and the carboxy-terminal. The amino-terminal domain was composed of 3 α-helices and 6 β-sheets, and the carboxy-terminal domain included 2 α-helices and 7 antiparallel β-sheets composition. The overall quality factor score of the SElW protein model was 98.08, with 93.24% of the amino acids having a Verify_3D score ≥0.2 and no amino acids located in disallowed regions. The docking conformation with the highest score (1 521.328) was selected as the analysis object, and the 19 hydrogen bonds between the corresponding amino acid residues of SElW and TCR were analyzed by PyMOL. Combined with sequence alignment and the published data, this study predicted and found five important superantigen active sites, namely Y18, N19, W55, C88, and C98. The highly purified soluble recombinant protein SElW was obtained with cloning, expression, and protein purification. Conclusions: The study found five superantigen active sites in SElW protein that need special attention and successfully constructed and expressed the SElW protein, which laid the foundation for further exploration of the immune recognition mechanism of SElW.

Primary central nervous system T-cell lymphoma in children and adolescents: a clinicopathological analysis of five cases / 中华病理学杂志

Objective: To study the clinicopathological characteristics, and further understand primary central nervous system T-cell lymphoma (PCNSTCL) in children and adolescents. Methods: Five cases of PCNSTCL in children and adolescents were collected from December 2016 to December 2021 at the First Affiliated Hospital of Zhengzhou University. The clinicopathological characteristics, immunophenotypic, and molecular pathologic features were analyzed, and relevant literatures reviewed. Results: There were two male and three female patients with a median age of 14 years (range 11 to 18 years). There were two peripheral T-cell lymphomas, not otherwise specified, two anaplastic large cell lymphoma, ALK-positive and one NK/T cell lymphoma. Pathologically, the tumor cells showed a variable histomorphologic spectrum, including small, medium and large cells with diffuse growth pattern and perivascular accentuation. Immunohistochemistry and in situ hybridization showed CD3 expression in four cases, and CD3 was lost in one case. CD5 expression was lost in four cases and retained in one case. ALK and CD30 were expressed in two cases. One tumor expressed CD56 and Epstein-Barr virus-encoded RNA. All cases showed a cytotoxic phenotype with expression of TIA1 and granzyme B. Three cases had a high Ki-67 index (>50%). T-cell receptor (TCR) gene rearrangement was clonal in two cases. Conclusions: PCNSTCL is rare, especially in children and adolescents. The morphology of PCNSTCL is diverse. Immunohistochemistry and TCR gene rearrangement play important roles in the diagnosis.

Molecular transduction in receptor-ligand systems by planar electromagnetic fields / Transdução molecular em sistemas receptor-ligante por campos electromagnéticos planares

The coupling of a ligand with a molecular receptor induces a signal that travels through the receptor, reaching the internal domain and triggering a response cascade. In previous work on T-cell receptors and their coupling with foreign antigens, we observed the presence of planar molecular patterns able to generate electromagnetic fields within the proteins. These planes showed a coherent (synchronized) behavior, replicating immediately in the intracellular domain that which occurred in the extracellular domain as the ligand was coupled. In the present study, we examined this molecular transduction - the capacity of the coupling signal to penetrate deep inside the receptor molecule and induce a response. We verified the presence of synchronized behavior in diverse receptorligand systems. To appreciate this diversity, we present four biochemically different systems - TCR-peptide, calcium pump-ADP, haemoglobin-oxygen, and gp120-CD4 viral coupling. The confirmation of synchronized molecular transduction in each of these systems suggests that the proposed mechanism would occur in all biochemical receptor-ligand systems.

A ligação de um ligante com um receptor molecular induz um sinal que viaja através do receptor, chegando ao domínio interno e disparando uma cascata de resposta. Em trabalhos anteriores em receptores de células T e sua ligação com antígenos estranhos, observamos a presença de padrões moleculares planares capazes de gerar campos eletromagnéticos dentro das proteínas. Esses planos mostraram um comportamento coerente (sincronizado), replicando, instantaneamente, no domínio intracelular o que ocorreu no domínio extracelular, enquanto o ligante era acoplado. No presente estudo, examinamos essa transdução ­ a capacidade de um sinal de acoplamento de penetrar profundamente a molécula receptora e induzir uma resposta. Verificamos a presença de um comportamento coerente em sistemas diversos de receptor-ligante. Para apreciar essa diversidade, apresentamos quatro sistemas bioquímicos diferentes: TCR-peptídeo, ADP-bomba de cálcio, hemoglobina-oxigênio e gp120-CD4 acoplamento viral. A confirmação de transdução molecular sincronizada em cada um desses sistemas sugere que o mecanismo proposto ocorreria em todos os sistemas bioquímicos receptor-ligante.

Clinicopathological features of mature T/NK cell lymphoma with aberrant CD20 or CD79α expression / 中华病理学杂志

Objective: To investigate the clinicopathological characteristics and prognosis of mature T/NK cell lymphomas with aberrant CD20 or CD79α expression. Methods: A retrospective analysis of 641 cases of mature T/NK cell lymphoma diagnosed from January 2014 to December 2020 was performed, and 14 cases of CD20-positive and one case of CD79α-positive mature T/NK-cell lymphoma were identified. Histological examination, immunohistochemical characterization, in situ hybridization for Epstein-Barr virus encoded early RNA (EBER), and PCR testing for immunoglobulin and T cell receptor (TCR) gene rearrangements were performed. Clinicopathological characteristics of these lymphomas were analyzed. Results: There were 13 males and 2 females, with a median age of 56 years. There were 8 cases of peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS), 3 cases of extranodal NK/T-cell lymphoma, nasal type (ENKTCL), 2 cases of monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) and 2 cases of angioimmunoblastic T-cell lymphoma (AITL). Twelve cases were stage Ⅲ or Ⅳ lymphomas. The prognosis was overall poor. The histology, immunophenotype and TCR gene rearrangement were not significantly different from the corresponding types of lymphoma. Ki-67 proliferation index was over 70% in all cases. The expression of CD20 or CD79α was weak and heterogeneous. All 15 case of Ig gene rearrangement were polyclonal. Conclusions: Mature T/NK cell lymphoma with abnormal expression of CD20 or CD79α is rare, commonly found in advanced stage, and associated with poor prognosis. The expression of CD20 or CD79α in these cases is weaker than the corresponding mature T/NK cell lymphomas, while its proliferation index is higher. Histomorphology, extensive immunoprofiling and molecular detection are required for accurate diagnosis.

Efficacy of Chimeric Antigen Receptor T Cell in the Treatment of Refractory/Recurrent B Acute Lymphocytic Leukemia in Children / 中国实验血液学杂志

OBJECTIVE@#To observe the efficacy of chimeric antigen receptor T cell (CAR-T) in the treatment of children with refractory/recurrent B acute lymphocytic leukemia (B-ALL).@*METHODS@#Thirty-two patients with r/r B-ALL were treated by CAR-T, the recurrence and death respectively were the end point events to evaluate the efficacy and safety of CAR-T.@*RESULTS@#The median age of the patients was 7.5 (2-17.5) years old; 40 times CAR-T were received in all patients and the median number of CAR-T was 0.9×107/kg; efficacy evaluation showed that 2 cases died before the first evaluation. Thirty patients showed that 3, 6, and 9-moth RFS was (96.3±3.6)%, (81.4±8.6)% and (65.3±12.5)%, respectively, while 3, 6, and 9-month OS was all 100%, and 12, 24-month OS was (94.7±5.1)% and (76±12.8)%. BM blasts≥36% before reinfusion and ferritin peak≥2 500 ng/ml within two weeks of CAR-T cell reinfusion were associated with recurrence. Adverse reactions mainly included cytokine release syndrome (CRS) and CART-cell-related encephalopathy syndrome (CRES), CRS appeared in 26 patients within a week of CAR-T cell reinfusion. CRES reaction was detected in 12 patients. Eighteen patients received intravenous drip of tocilizumab, among them, 12 combined with glucocorticoid. CRS and CRES reactions were relieved within one week after treatment. Hormone dosage was related to the duration of remission in patients, and the cumulative dose of methylprednisolone≥8 mg/kg showed a poor prognosis.@*CONCLUSION@#CAR-T is a safe and effective treatment for r/r B-ALL, most CRS and CRES reactions are reversible. BM blasts ≥36% before reinfusion and cumulative dose of methylprednisolone ≥8 mg/kg after reinfusion both affect the therapeutic effect. Ferritin≥2 500 ng/ml within two weeks after reinfusion is related to disease recurrence and is an independent prognostic risk factor.

Preparation of CD52-targeted chimeric antigen receptor-modified T cells and their anti-leukemia effects / 中华血液学杂志

Objective: To construct chimeric antigen receptor (CAR) T cells targeting CD52 (CD52 CAR-T) and validate the effect of CD52 CAR-T cells on CD52-positive leukemia. Methods: A second-generation CD52-targeting CAR bearing 4-1BB costimulatory domain was ligated into a lentiviral vector through molecular cloning. Lentivirus was prepared and packaged by 293 T cells with a four-plasmid system. Fluorescein was used to label cell surface antigens to evaluate the phenotype of CD52 CAR-T cells after infection. Flow cytometry and ELISA were used to evaluate the specific cytotoxicity of CD52 CAR-T cells to CD52-positive cell lines in vitro. Results: ①A pCDH-CD52scFv-CD8α-4-1BB-CD3ζ-GFP expressing plasmid was successfully constructed and used to transduce T cells expressing a novel CD52-targeting CAR. ②On day 6, CD52-positive T cells were almost killed by CD52-targeted CAR-T post lentivirus transduction [CD52 CAR-T (4.48 ± 4.99) %, vs Vector-T (56.58±19.8) %, P=0.011]. ③T cells transduced with the CAR targeting CD52 showed low levels of apoptosis and could be expanded long-term ex vivo. ④The CD52 CAR could promote T cell differentiation into central and effector memory T cells, whereas the proportion of T cells with a CD45RA(+) effector memory phenotype were reduced. ⑤CD52 CAR-T cells could specifically kill CD52-positive HuT78-19t cells but had no killing effect on CD52-negative MOLT4-19t cells. For CD52 CAR-T cells, the percentage of residual of HuT78-19t cells was (2.66±1.60) % at an the E:T ratio of 1∶1 for 24 h, while (56.66±5.74) % of MOLT4-19t cells survived (P<0.001) . ⑥The results of a degranulation experiment confirmed that HuT78-19t cells significantly activated CD52 CAR-T cells but not MOLT4-19t cells[ (57.34±11.25) % vs (13.06± 4.23) %, P<0.001]. ⑦CD52 CAR-T cells released more cytokines when co-cultured with HuT78-19t cells than that of vector-T cells [IFN-γ: (3706±226) pg/ml, P<0.001; TNF-α: (1732±560) pg/ml, P<0.01]. Conclusions: We successfully prepared CD52 CAR-T cells with anti-leukemia effects, which might provide the foundation for further immunotherapy.

Enfermedad residual medible mediante reordenamientos de inmunoglobulinas y receptores de linfocitos-T / Measurable residual disease by rearrangements of immunoglobulins and T-lymphocyte receptors

Resumen Las leucemias agudas constituyen la neoplasia más frecuente en pacientes pediátricos. Actualmente, el 80% de los niños con leucemia linfoblástica aguda (LLA) logran curarse con quimioterapia con vencional pero el 20% de los mismos presentarán una reaparición de la enfermedad. La enfermedad residual medible (ERM) ha sido descripta como un importante factor pronóstico, que permite evaluar la respuesta de los pacientes al tratamiento. Una de las técnicas más sensibles par a estudiar ERM es la cuantificación de reordena mientos génicos de inmunoglobulinas (Ig) y receptores de linfocitos-T (TCR). Los objetivos del presente trabajo fueron describir los reordenamientos detectados de Ig/TCR, evaluar el efecto de la ERM en la supervivencia de niños con LLA y comparar la ERM por Ig/TCR con la cuantificada mediante citometría de flujo multiparamétrica (CFM). Del total de 455 pacientes estudiados, en el 96% fue posible caracterizar al menos un reordenamiento de Ig/TCR. El total de reordenamientos clonales detectados fue de 1550. La ERM pudo ser estudiada en forma exitosa en el 89% de los casos. El valor de ERM positiva combinada al día 33 y 78 de tratamiento, permitió identificar pacientes de alto riesgo, entre los previamente estratificados por la ERM mediante CFM al día 15. La comparación entre la determinación de ERM mediante reordenamientos Ig/TCR y CFM mostró una excelente correlación. El presente trabajo constituye un estudio de ERM mediante Ig/TCR realizado en un número muy significativo de pacientes diagnosticados en forma consecutiva, tratados en el marco de un protocolo homogéneo y con excelente seguimiento clínico.

Abstract Acute leukemias are the most common neoplasm in pediatric patients. Currently, 80% of children with diagnosis of acute lymphoblastic leukemia (ALL) are cured with conventional chemotherapy, but 20% of them will have a recurrence of the disease. Measurable Residual Disease (MRD) has been described as an important prognostic factor that allows evaluating the response of patients to treatment. One of the most sensitive techniques to study MRD is the quantification of immunoglobulins (Ig) and T-lymphocyte receptors (TCR) genes rearrangements. The aims of this study were to describe the detected Ig/TCR rearrangements, to evaluate the prognostic impact of MRD in our population of children with ALL and to compare the MRD values by Ig/TCR with those obtained by multiparametric flow cytometry (MFC). A total of 455 patients were studied. In 96% of the cases, it was possible to characterize at least one Ig/TCR rearrangement. The total number of Ig/TCR rear rangements detected was 1550. MRD was successfully applied in 89% of the cases. The combined positive MRD values at day 33 and 78 of treatment allow the identification of high-risk patients in cases previously stratified by MRD using flow cytometry at day 15. The comparison between MRD determination by Ig/TCR rearrangements and FC showed excellent correlation. The present work constitutes a study of MRD by Ig/TCR carried out in a very significant number of patients consecutively diagnosed, treated within a homogeneous protocol and with excellent clinical follow-up.

Interpretation of ASTCT Consensus Responses by Chimeric Antigen Receptor T Cell Therapy CRS/ICANS--Review / 中国实验血液学杂志

Chimeric antigen receptor T cell (CAR-T) therapy was awarded as the largest research breakthrough in 2017 by the American Society of Clinical Oncology, at present, it is rapidly becoming the most promising new treatment for hematological malignancies. However, this therapy also produces a new challenge: toxic adverse events such as cytokine release syndrome (CRS) and neurotoxicity, partial of them can bring death to the patients. The incidence and severity of the above toxic events in different multi-center trial reports are also different, which may be attributed to the different in the considerably variable assessment and grading of toxicities between clinical trials and across institutions. The ASTCT published at 2018 advanced the consensus grading for cytokine release syndrome and neurologic toxicity associated with immune effector cells, it was focusing on CRS and neurotoxicity associated with immune effector cells. In order to provide reference for the development of relevant work in this field and the formulation of security strategies in our country, the main content of the consensus was summarized briefly.

The Genome-Wide Changes in Expression Profile of CML T Cells After Up-regulation of TCRζ Chain Expression / 中国实验血液学杂志

OBJECTIVE@#To analyze the changes in the gene expression profile of T cells in CML patients after TCRζ up-regulation expression, and to explore the molecular mechanism of T cell reactivation after transgenic up-regulation of TCRζ.@*METHODS@#The peripheral blood mononuclear cells(PBMCs) from 3 newly untreated chronic-stage CML patients were collected, and the CD3@*RESULTS@#A total of 2248 differentially-expressed genes were obtained, including 553 up-regulated genes and 1695 down-regulated genes in experimental group as compared with those in control group (P<0.05) . The GO and KEGG enrichment analyses showed that differentially expressed genes involved in the biological processes related to T cell immune function, such as TCR signaling pathway, T cell proliferation and activation. Some of core genes involved in promoting the TCR signaling pathway, T cell proliferation, activation and apoptosis pathways were significantly up-regulated, while some core genes involved in inhibiting T cell activation were significantly down-regulated.@*CONCLUSION@#The molecular mechanism of the significantly improved T cell activation and proliferation ability in CML patients after TCRζ up-regulation may be related to the differential transcripts mediated signaling pathways of T cell activation, proliferation and apoptosis.

Research Advances in the Treatment of B-Cell Acute Lymphoblastic Leukemia Based on Surface Antigen Expression --Review / 中国实验血液学杂志

B-cell acute lymphoblastic leukemia (B-ALL) is a common malignant tumor in hematopoietic system. Although the remission rate of the patients with adult B-ALL is similar to those with childhood B-ALL, the rate of long-term disease-free survival (DFS) rate is significantly lower, once recurrence, the remission rate of routine chemotherapy is low and the prognosis is so poor. Based on the expression of tumor cell surface antigens(such as CD19, CD20 and CD22), the specific monoclonal antibodies, bispecific antibodies and chimeric antigen receptor T cells (CAR-T), and other targeted immunotherapy can greatly improve the efficacy of B-ALL patients, especially for patients with relapse and refractory. In this review, the progress of immunotherapy against B-ALL cell surface antigen is summarized briefly.

Target and Manufacturing of Chimeric Antigen Receptor T cells for T-cell Malignancies--Review / 中国实验血液学杂志

T lymphoid malignancy is a group of highly heterogeneous hematological tumors. Disease recurrence and resistance to therapy are the common causes of failed treatment. Traditional therapy is radiotherapy and chemotherapy, although it has achieved great success. However, many patients still failed to survive following the treatment. With the introduction of monoclonal antibodies, immunotherapy and cellular therapy into clinical practice, the outcome of hematologic malignancies has been significantly improved. In particular, chimeric antigen receptor T cells (CAR-T) showed high efficacy in treating B-cell lymphoma and acute B lymphocytic leukemia and surpassed any previous therapeutic strategies. However, this treatment seldom succeeded in treating T cell malignancies. In this review, the history of CAR-T cells treating T cell malignancies, and the clinical trials, adverse events of previously reported were summarized briefly.

First Case of Double T-Cell Receptor Alpha/Delta Rearrangements of t(11;14) and inv(14) and Subsequent JAK2 Rearrangement in a Patient With T-cell Acute Lymphoblastic Leukemia

No abstract available.

A giant step forward: chimeric antigen receptor T-cell therapy for lymphoma / 医学前沿

The combination of the immunotherapy (i.e., the use of monoclonal antibodies) and the conventional chemotherapy increases the long-term survival of patients with lymphoma. However, for patients with relapsed or treatment-resistant lymphoma, a novel treatment approach is urgently needed. Chimeric antigen receptor T (CAR-T) cells were introduced as a treatment for these patients. Based on recent clinical data, approximately 50% of patients with relapsed or refractory B-cell lymphoma achieved complete remission after receiving the CD19 CAR-T cell therapy. Moreover, clinical data revealed that some patients remained in remission for more than two years after the CAR-T cell therapy. Other than the CD19-targeted CAR-T, the novel target antigens, such as CD20, CD22, CD30, and CD37, which were greatly expressed on lymphoma cells, were studied under preclinical and clinical evaluations for use in the treatment of lymphoma. Nonetheless, the CAR-T therapy was usually associated with potentially lethal adverse effects, such as the cytokine release syndrome and the neurotoxicity. Therefore, optimizing the structure of CAR, creating new drugs, and combining CAR-T cell therapy with stem cell transplantation are potential solutions to increase the effectiveness of treatment and reduce the toxicity in patients with lymphoma after the CAR-T cell therapy.

Different sites of extranodal involvement may affect the survival of patients with relapsed or refractory non-Hodgkin lymphoma after chimeric antigen receptor T cell therapy / 医学前沿

Factors associated with complete and durable remissions after anti-CD19 chimeric antigen receptor T (CAR-T) cell immunotherapy for relapsed or refractory non-Hodgkin lymphoma (r/r NHL) have not been well characterized. In this study, we found that the different sites of extranodal involvement may affect response, overall survival (OS), and progression-free survival (PFS) in patients with r/r NHL treated with anti-CD19 CAR-T cells. In a cohort of 32 treated patients, 12 (37.5%) and 8 (25%) patients exhibited soft tissue lymphoma and bone marrow (BM) infiltrations, respectively, and 13 (41%) patients exhibited infiltration at other sites. The factors that may affect prognosis were identified through multivariable analysis. As an independent risk factor, soft tissue infiltration was the only factor significantly correlated with adverse prognosis (P < 0.05), whereas other factors did not reach statistical significance. Furthermore, the site of extranodal tumor infiltration significantly and negatively affected OS and PFS in patients with r/r NHL treated with anti-CD19 CAR-T cell therapy. PFS and OS in patients with BM involvement were not significantly different from those of patients with lymph node involvement alone. Thus, anti-CD19 CAR-T cell therapy may improve the prognosis of patients with BM infiltration.

CD24⁺ Cell Depletion Permits Effective Enrichment of Thymic iNKT Cells While Preserving Their Subset Composition

Invariant NKT (iNKT) cells are a small subset of thymus-generated T cells that produce cytokines to control both innate and adaptive immunity. Because of their very low frequency in the thymus, in-depth characterization of iNKT cells can be facilitated by their enrichment from total thymocytes. Magnetic-activated cell sorting (MACS) of glycolipid antigen-loaded CD1d-tetramer-binding cells is a commonly used method to enrich iNKT cells. Surprisingly, we found that this procedure also dramatically altered the subset composition of enriched iNKT cells. As such, NKT2 lineage cells that express large amounts of the transcription factor promyelocytic leukemia zinc finger were markedly over-represented, while NKT1 lineage cells expressing the transcription factor T-bet were significantly reduced. To overcome this limitation, here, we tested magnetic-activated depletion of CD24⁺ immature thymocytes as an alternative method to enrich iNKT cells. We found that the overall recovery in iNKT cell numbers did not differ between these 2 methods. However, enrichment by CD24⁺ cell depletion preserved the subset composition of iNKT cells in the thymus, and thus permitted accurate and reproducible analysis of thymic iNKT cells in further detail.

T cell receptor excision circles as a tool for evaluating thymic function in young children

The thymus is a primary lymphoid organ responsible for the maturation of T cells as well as the immunological central tolerance. It is in the antenatal period and infancy that it plays its major role. In clinical practice, T cell receptor excision circles (TRECs) are considered a direct and reliable measure of the thymic function. TRECs are a by-product of DNA formation in gene rearrangement of T cell receptors. They are stable and they do not duplicate during mitosis, representing the recent emigrant T cells from the thymus. Despite their importance, TRECs have been neglected by physicians and there is a lack of data regarding thymic function during infancy of healthy children. In order to evaluate thymic function in the first years of life, we propose measuring TRECs as a valuable tool. One hundred and three blood samples from children and adolescents between 3 months and 20 years of age were analyzed. The mean TRECs count was 136.77±96.7 copies of TRECs/μL of DNA. The individuals between 0 and 5 years of age had significantly higher TRECs values than those between 10 and 20 years of age. No significant difference was observed in TRECs values among age groups below 5 years of age. An inverse correlation between TRECs and age was found (r=0.3 P=0.003). These data highlight and validate the evidence of decreased thymus function with age, even during infancy. Awareness should be raised with this important albeit ignored organ.

High-affinity T cell receptors redirect cytokine-activated T cells (CAT) to kill cancer cells / 医学前沿

Cytokine-activated T cells (CATs) can be easily expanded and are widely applied to cancer immunotherapy. However, the good efficacy of CATs is rarely reported in clinical applications because CATs have no or very low antigen specificity. The low-efficacy problem can be resolved using T cell antigen receptor-engineered CAT (TCR-CAT). Herein, we demonstrate that NY-ESO-1 HLA-A*02:01-specific high-affinity TCR (HAT)-transduced CATs can specifically kill cancer cells with good efficacy. With low micromolar range dissociation equilibrium constants, HAT-transduced CATs showed good specificity with no off-target killing. Furthermore, the high-affinity TCR-CATs delivered significantly better activation and cytotoxicity than the equivalent TCR-engineered T cells (TCR-Ts) in terms of interferon-γ and granzyme B production and in vitro cancer cell killing ability. TCR-CAT may be a very good alternative to the expensive TCR-T, which is considered an effective personalized cyto-immunotherapy.