The COVID-19 pandemic in sub-Saharan Africa: The significance of presumed immune sufficiency

A novel coronavirus known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first reported in China in 2019 and later ignited a global pandemic. Contrary to expectations, the effect of the pandemic was not as devastating to Africa and its young population compared to the rest of the world. To provide insight into the possible reasons for the presumed immune sufficiency to coronavirus disease 2019 (COVID-19) in Africa, this review critically examines literature published from 2020 onwards on the dynamics of COVID-19 infection and immunity and how other prevalent infectious diseases in Africa might have influenced the outcome of COVID-19. Studies characterising the immune response in patients with COVID-19 show that the correlates of protection in infected individuals are T-cell responses against the SARSCoV-2 spike protein and neutralising titres of immunoglobin G and immunoglobin A antibodies. In some other studies, substantial pre-existing T-cell reactivity to SARS-CoV-2 was detected in many people from diverse geographical locations without a history of exposure. Certain studies also suggest that innate immune memory, which offers protection against reinfection with the same or another pathogen, might influence the severity of COVID-19. In addition, an initial analysis of epidemiological data showed that COVID-19 cases were not severe in some countries that implemented universal Bacillus Calmette­Guerin (BCG) vaccination policies, thus supporting the potential of BCG vaccination to boost innate immunity. The high burden of infectious diseases and the extensive vaccination campaigns previously conducted in Africa could have induced specific and non-specific protective immunity to infectious pathogens in Africans.

Caracterização das infecções que acometem o usuário no momento do diagnóstico para o Hiv/Aids / Characterization of infections that affect the user at the moment of diagnosis for Hiv/Aids / Caracterización de las infecciones que afectan a los usuarios en el momento del diagnóstico del Vih/Sida

: O estado do Pará, de 2009 a 2019, apresentou um aumento de 46,5% na taxa de detecção de aids. O que destaca a importância de estudos para a avaliação e acompanhamento deste público. Objetivo: Analisar as infecções que acometem os usuários de um centro de referência no momento de seu diagnóstico para a infecção pelo HIV. Métodos: Estudo descritivo, realizado em um centro de referência da cidade de Santarém, Pará. A amostra foi de 332 prontuários de pacientes diagnosticados para o HIV nos anos de 2016 e 2017. A coleta de dados buscou informações sociodemográficas, clínicas e imunológicas dos pacientes no momento do diagnóstico para a infecção pelo HIV. Os dados foram organizados e analisados por estatística descritiva e inferencial, adotando- se p<0,05. Resultados: Observou-se prevalência do sexo masculino (67%), faixa etária de 15-24 anos (32,2%), solteiros (59%), com vínculo empregatício (64,5%), contagem de linfócitos T CD4+ ≥200 céls/mm3 (54,8%) e carga viral detectável (75,3%). A Candidíase (25%) e a Tuberculose (25%) predominaram como infecções oportunistas (IO), e a Sífilis (67,5%) como outras infecções. Conclusão: Conforme método proposto e os dados já informados, conclui-se que o diagnóstico para a Sífilis se associou ao sexo masculino, bem como a situação de contagem de linfócitos T CD4+ <200 céls/mm3 se associou com a presença de alguma infecção oportunista, da instalação da Candidíase e da Tuberculose.

Introduction: The state of Pará, from 2009 to 2019, showed a 46.5% increase in the AIDS detection rate. What stands out the importance of studies for the evaluation and monitoring of this public. Objective: Analyze the infections that affect the users of a reference center at the moment of diagnosis for HIV infection. Methods: Descriptive study, carried out in a reference center in the city of Santarém, Pará. The sample consisted of 332 records of patients diagnosed with HIV in the years 2016 and 2017. The data collection sought sociodemographic, clinical and immunological information of the patients at the moment diagnosis for HIV infection. The data were organized and analyzed using descriptive and inferential statistics, adopting p <0.05. Results: There was a prevalence of males (67%), aged 15-24 years (32.2%), single (59%), with employment (64.5%), CD4 + T lymphocyte count ≥200 cells/mm3 (54.8%) and detectable viral load (75.3%). Candidiasis (25%) and Tuberculosis (25%) predominated as opportunistic infections (IO), and Syphilis (67.5%) as other infections. Conclusion: According to the proposed method and the data already reported, it is concluded that the diagnosis for Syphilis was associated with the male gender, as well as the situation of CD4 + T lymphocyte count <200 cells/mm3 was associated with the presence of some opportunistic infection, of the installation of Candidiasis and Tuberculosis.

Introducción: El estado de Pará, de 2009 a 2019, presentó un aumento del 46,5% en la tasa de detección del SIDA. Lo que pone de manifiesto la importancia de los estudios para la evaluación y el seguimiento de este público. Objetivo: Analizar las infecciones que sufren los usuarios de un centro de referencia en el momento de su diagnóstico de infección por VIH. Métodos: Estudo descritivo, realizado em um centro de referência da cidade de Santarém, Pará. La muestra fue de 332 historias clínicas de pacientes diagnosticados de VIH en los años 2016 y 2017. La recogida de datos buscaba información sociodemográfica, clínica e inmunológica de los pacientes en el momento del diagnóstico de la infección por VIH. Los datos se organizaron y analizaron mediante estadísticas descriptivas e inferenciales, adoptando p<0,05. Resultados: Se observó la prevalencia del sexo masculino (67%), el grupo de edad de 15 a 24 años (32,2%), la soltería (59%), el empleo (64,5%), el recuento de linfocitos T CD4+ ≥200 células/mm3 (54,8%) y la carga viral detectable (75,3%). La candidiasis (25%) y la tuberculosis (25%) predominaron como infecciones oportunistas (IO), y la sífilis (67,5%) como otras infecciones. Conclusión: De acuerdo con el método propuesto y los datos ya informados, se concluye que el diagnóstico de Sífilis se asocia al sexo masculino, así como la situación de contagio de linfocitos T CD4+ <200 células/mm3 se asocia a la presencia de alguna infección oportunista, a la instauración de la Candidiasis y a la Tuberculosis.

Alergia alimentar não IgE mediada: proctocolite induzida por proteínas alimentares ­ Atualização / Non-IgE mediated food allergy: food protein-induced allergic proctocolitis ­ An update

Nas últimas décadas observa-se aumento na prevalência mundial de alergia alimentar, que já acomete aproximadamente 6% das crianças, atribuído à interação entre fatores genéticos, ambientais e alterações na resposta imunológica e pode envolver reações mediadas por IgE, não mediadas e mistas. As formas não IgE mediadas decorrem de reação de hipersensibilidade tardia, mediada por linfócitos T e afetam prioritariamente o trato gastrointestinal, como a Síndrome da enterocolite induzida por proteína alimentar (FPIES), Síndrome da proctocolite alérgica induzida por proteína alimentar (FPIAP), Síndrome da enteropatia induzida por proteína alimentar (FPE) e doença celíaca. As características destas reações podem ser diferenciadas por sua apresentação clínica, gravidade, idade de início e história natural. Entre as reações alérgicas aos alimentos não IgE mediadas, a proctocolite alérgica é a mais frequente. Geralmente ocorre no primeiro ano de vida e apresenta excelente prognóstico. Embora costume ter um curso benigno, traz grande preocupação aos cuidadores por frequentemente cursar com quadro de hematoquezia exigindo diagnóstico diferencial adequado. O conhecimento e manejo da proctocolite alérgica é de suma importância para a prática médica em Alergia e Imunologia. Seu diagnóstico é baseado na história clínica seguindo-se dieta de exclusão, especialmente do leite de vaca, com subsequente provocação oral, que geralmente pode ser realizada no domicílio. O diagnóstico preciso é importante, para se evitar dietas de exclusão desnecessárias. Nesta revisão foram utilizados artigos publicados nos últimos anos, com busca realizada através da base PubMed envolvendo revisões, diagnóstico e tratamento de alergias não IgE mediadas, com foco em proctocolite alérgica.

An increase in the worldwide prevalence of food allergies has been observed in the past decades, currently affecting 6% of children. This increase has been associated with the interaction between genetic, environmental, and immune response factors and can be observed in IgE, non-IgE, and mixed mediated reactions. Non-IgE mediated food allergies result from delayed-type hypersensitivity and mostly affect the gastrointestinal tract, such as food protein-induced enterocolitis syndrome (FPIES), food protein-induced allergic proctocolitis (FPIAP), food protein-induced enteropathy (FPE), and celiac disease. These reactions can be differentiated by their clinical presentation, severity, age at onset, and natural history. Among non-IgE-mediated allergic reactions to food, allergic proctocolitis is the most frequent. It usually develops in the first year of life and has excellent prognosis. Although it has a benign course, allergic proctocolitis is challenging for health care professionals because it often presents with hematochezia, requiring an accurate differential diagnosis. Knowledge and management of allergic proctocolitis is of paramount importance for medical practice in allergy and immunology. Its diagnosis is based on clinical history followed by elimination diet, especially cow's milk, with subsequent oral food challenge, which may usually be performed at home. Accurate diagnosis is important to avoid unnecessary elimination diets. For this review, PubMed database was searched for recently published literature reviews and studies on the diagnosis and treatment of non- IgE mediated allergies, with a focus on allergic proctocolitis.

Imunologia da tuberculose: uma revisão narrativa da literatura / Tuberculosis immunology: a narrative literature review

A resposta imune desenvolvida pelo hospedeiro contra o Mycobacterium tuberculosis é considerada de natureza complexa e multifacetada. Esta interação bacilo-hospedeiro resulta, na maioria das vezes, em uma infecção latente assintomática, podendo ou não evoluir para a forma ativa da tuberculose (TB). O presente estudo objetivou atualizar e sumarizar o conhecimento científico acerca dos mecanismos imunológicos associados à infecção e sua progressão para a TB ativa. Trata-se de uma revisão narrativa, realizada a partir do levantamento bibliográfico de artigos científicos indexados nas bases de dados PubMed/MEDLINE e SciELO, nos últimos 20 anos. Nas últimas décadas, a caracterização de linfócitos Tγδ, MAIT, iNKT e outra células T CD1 restritas proporcionaram um maior entendimento do papel da imunidade inata na infecção pelo bacilo. A migração de linfócitos T CD4+ produtores de IFN-g, TNF-α e de outras moléculas solúveis, promove o recrutamento e formação do granuloma, estrutura que beneficia tanto o hospedeiro quanto o bacilo. Eventualmente, um desequilíbrio nesta complexa rede de interação, resulta em uma resposta inflamatória exacerbada que contribui para o desenvolvimento de um granuloma necrótico. Por fim, a exaustão da resposta imune local frente à contínua exposição ao bacilo, associada ao perfil anti-inflamatório dos linfócitos Th2 e linfócitos Treg, favorecem a inativação funcional e, consequentemente, o desenvolvimento da doença ativa. A resposta imunológica é crucial para o desenvolvimento da infecção por M. tuberculosis. Portanto, estudos que possibilitem uma maior compreensão sobre a interação bacilohospedeiro podem viabilizar o desenvolvimento de novos métodos diagnósticos, estratégias terapêuticas e, sobretudo, avanços no desenvolvimento de imunobiológicos.

The immune response developed by the host against Mycobacterium tuberculosis is considered a complex and multifaceted nature. This host-bacillus interaction, which in most cases results in an asymptomatic latent infection that may or may not evolve to the development of active pulmonary tuberculosis (TB). The present study aimed to update and summarize the current scientific knowledge regarding the immunological mechanisms associated with infection and the development of active disease. This is a narrative review, based on scientific articles indexed in the PubMed/ MEDLINE and SciELO databases over the last 20 years. In recent decades, the characterization of Tγδ lymphocytes, MAIT, iNKT and CD1-restricted T cells has provided a better understanding of the role of innate immunity in bacilli infection. The migration of T CD4+ lymphocytes that produce IFN-γ, TNF-α and other soluble molecules, promotes the recruitment and formation of the granuloma, a structure that benefits both the host and the bacillus. Eventually, an imbalance in this complex interaction network results in an exacerbated inflammatory response that contributes to the development of a necrotic granuloma. Finally, exhaustion of the local immune response due to continuous exposure to the bacillus, associated with the anti-inflammatory profile of Th2 lymphocytes and Treg lymphocytes, favor functional inactivation and, consequently, the development of active disease. The immune response is crucial for the development of M. tuberculosis infection. Therefore, studies that enable a greater understanding of the hostbacillus interaction may enable the development of new diagnostic methods, therapeutic strategies and, above all, advances in the development of immunobiologicals.

Trasplante pulmonar: una perspectiva desde la inmunología / Lung transplantation: a perspective from immunology

Resumen El trasplante pulmonar implica una serie de desafíos, que como lo ha demostrado la historia, no sólo depende de un adecuado desarrollo de técnicas quirúrgicas, sino también de la comprensión de una serie de complejas interacciones inmunológicas celulares y humorales que serán las responsables del tipo de respuesta (innata y/o adquirida) fisiológica y que pudiesen desencadenar las complicaciones asociadas al trasplante (rechazo hiperagudo, agudo o crónico). Cada una de las cuales tiene su potencial prevención y/o tratamiento. El poder conocer esta serie de respuestas, permite al clínico anticiparse a algunos de estos eventos y evitar de mejor forma el daño y las consecuencias que pueden producir en los casos de trasplante pulmonar.

Lung transplantation involves a series of challenges, which as history has shown, depends not only on an adequate development of surgical techniques, but also on the understanding of a series of complex cellular and humoral immunological interactions that will be responsible for the type of physiological response (innate - acquired) and that could trigger the complications associated with transplantation (hyperacute, acute or chronic rejection). Each of which has its potential prevention and treatment. Being able to know this series of responses, allows the clinician to anticipate some of these events and to avoid in a better way the damage and the consequences that can occur in cases of lung transplantation.

CAR T cells redirected against tumor-specific antigen glycoforms: can low-sugar antigens guarantee a sweet success? / 医学前沿

Immune-based therapies have experienced a pronounced breakthrough in the past decades as they acquired multiple US Food and Drug Administration (FDA) approvals for various indications. To date, six chimeric antigen receptor T cell (CAR-T) therapies have been permitted for the treatment of certain patients with relapsed/refractory hematologic malignancies. However, several clinical trials of solid tumor CAR-T therapies were prematurely terminated, or they reported life-threatening treatment-related damages to healthy tissues. The simultaneous expression of target antigens by healthy organs and tumor cells is partly responsible for such toxicities. Alongside targeting tumor-specific antigens, targeting the aberrantly glycosylated glycoforms of tumor-associated antigens can also minimize the off-tumor effects of CAR-T therapies. Tn, T, and sialyl-Tn antigens have been reported to be involved in tumor progression and metastasis, and their expression results from the dysregulation of a series of glycosyltransferases and the endoplasmic reticulum protein chaperone, Cosmc. Moreover, these glycoforms have been associated with various types of cancers, including prostate, breast, colon, gastric, and lung cancers. Here, we discuss how underglycosylated antigens emerge and then detail the latest advances in the development of CAR-T-based immunotherapies that target some of such antigens.

Chidamide inhibits the NOTCH1-MYC signaling axis in T-cell acute lymphoblastic leukemia / 医学前沿

T-cell acute lymphoblastic leukemia (T-ALL) is one of the most dangerous hematological malignancies, with high tumor heterogeneity and poor prognosis. More than 60% of T-ALL patients carry NOTCH1 gene mutations, leading to abnormal expression of downstream target genes and aberrant activation of various signaling pathways. We found that chidamide, an HDAC inhibitor, exerts an antitumor effect on T-ALL cell lines and primary cells including an anti-NOTCH1 activity. In particular, chidamide inhibits the NOTCH1-MYC signaling axis by down-regulating the level of the intracellular form of NOTCH1 (NICD1) as well as MYC, partly through their ubiquitination and degradation by the proteasome pathway. We also report here the preliminary results of our clinical trial supporting that a treatment by chidamide reduces minimal residual disease (MRD) in patients and is well tolerated. Our results highlight the effectiveness and safety of chidamide in the treatment of T-ALL patients, including those with NOTCH1 mutations and open the way to a new therapeutic strategy for these patients.

Effect of γδ T cells on the Proliferation, Apoptosis and Autophagy of Multiple Myeloma Cells / 中国实验血液学杂志

AbstractObjective: To investigate the effect of γδ T cells on the proliferation, apoptosis and autophagy of multiple myeloma cells.@*METHODS@#Peripheral blood mononuclear cells (PBMNC) were isolated from healthy volunteers, and stimulated with zoledronic acid (Zol) in combination with rhIL-2. Flow cytometry analysis was used to detected the purity of γδ T cells. γδ T cells were collected and co-cultured with RPMI-8226 or U-266 cells at different effector target ratios. The proliferation of RPMI-8226 or U-266 cell lines were detected by CCK-8. Cell cycle and cell apoptosis were detected by flow cytometry and Western blot．The expressions of autophagy-related proteins were detected by Western blot.@*RESULTS@#γδ T cells can be expanded in vitro. γδ T cells could inhibit the proliferation of RPMI-8226 or U-266 cells, induced cell cycle arrest and promoted apoptosis in an effector target-dependent manner. In addition, γδ T cells could induce autophagy of myeloma cells, inhibited the expression of autophagy-related PI3K, P-AKT and P-mTOR, while increased the expression of AMPK and Beclin-1.@*CONCLUSION@#γδ T cells can inhibit the proliferation of RPMI-8226 and U-266 myeloma cells, induce cell cycle arrest, promote apoptosis, and enhance autophagy in vitro. The mechanism may be related to inhibition of PI3K/AKT/mTOR signaling pathway and/or activation of AMPK/Beclin-1 signaling pathway.

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.

Pharmacokinetic study of anti-human T-cell porcine immunoglobulin combined with cyclosporine A immunosuppressive therapy in patients with severe aplastic anemia / 中华血液学杂志

Objective: To study the metabolic characteristics of anti-human T-cell porcine immunoglobulin (p-ATG) in patients with severe aplastic anemia (SAA) . Methods: For patients with SAA treated with p-ATG combined cyclosporine A (CsA) immunosuppressants between February 2017 and December 2017, the p-ATG dose was 20 mg·kg(-1)·d(-1) over 12 h of intravenous administration for 5 consecutive days. The blood concentration of p-ATG was detected by the three-antibody sandwich ELISA method, the pharmacokinetic analysis software was fitted, and the second-chamber model method was used to calculate the pharmacokinetic parameters and plot the pharmacokinetic curve. Adverse events were recorded and the hematologic reactions were determined at 6 months after treatment. Results: Sixteen patients with SAA treated with p-ATG were enrolled, including 8 females and 8 males, with a median age of 22 years (range, 12 to 49 years) and a median weight of 62.5 kg (range, 37.5 to 82.0 kg) . The pharmacokinetics of p-ATG could be evaluated in 14 cases. p-ATG is distributed in vivo as a two-chamber model, with an average drug concentration peak (T(max)) of (5.786±2.486) days, a peak concentration (C(max)) of (616±452) mg/L, and a half-life of (10.479±8.242) days. The area under the drug time curve (AUC) was (5.807±3.236) mg/L·d. Six months after treatment, 8 of 14 patients received a hematologic response; the AUC (0-t) of the effective group and ineffective groups was (7.50±3.26) mg/L·d vs (4.50±2.18) mg/L·d, and the C(max) was (627±476) mg/L vs (584±382) mg/L, respectively. Conclusion: The plasma concentration of p-ATG reached a peak after 5 days of continuous infusion, and then decreased slowly, with a half-life of 10.479 days, and the residual drug concentration was detected in the body 60 days after administration. A relationship between drug metabolism and efficacy and adverse reactions could not be determined.

Preparation of CD33 targeted bispecific- and trispecific-T cell engagers and their cytotoxicity on leukemia cells / 中华血液学杂志

Objective: To investigate the effect of CD33-targeted bi-specific and tri-specific T-cell engagers on T-cell proliferation and explore their cytotoxicity on leukemia cells. Methods: The CD33-targeted bi-specific T-cell engager (CD33-BiTE) and tri-specific T-cell engager (CD33-TriTE) expression vectors were successfully constructed and expressed through a eukaryotic cell expression system. CD33-BiTE and CD33-TriTE were purified by affinity chromatography. The effects of CD33-BiTE and CD33-TriTE on T cells were analyzed through in vitro experiments. Results: ① CD33-BiTE and CD33-TriTE were successfully constructed and purified and could compete with flow cytometry antibodies for binding to the target cells. ② After 12 days of co-culture with CD33-BiTE and CD33-TriTE, the number of human T cells were expanded to 33.89±19.46 and 81.56±23.62 folds, respectively. CD33-TriTE induced a stronger proliferation of T cells than CD33-BiTE (P<0.05) . ③ Both CD33-BiTE and CD33-TriTE induced specific dose-dependent cytotoxicity on CD33(+) leukemia cells. ④ Compared to CD33-TriTE, leukemia cells were prone to express PD-L1 when co-cultured with T cells and CD33-BiTE. CD33-TriTE induced powerful cytotoxicity on leukemia cells with high PD-L1 expression. Conclusion: CD33-BiTE and CD33-TriTE expression vectors were constructed, and fusion proteins were expressed in eukaryotic cells. Our results support the proliferative and activating effects of BiTE and TriTE on T cells. Compared to that of CD33-BiTE, CD33-TriTE induced a stronger proliferative effect on T cells and a more powerful cytotoxicity on leukemia cells with high PD-L1 expression.

Functional investigation of chimeric antigen receptor T cells targeting LMP1 antigen / 中华血液学杂志

Objective: This study aimed to create a type of CAR-T cells that targets LMP1 antigen and study its immunotherapeutic effect on LMP1-positive hematological malignancies. Methods: To generate LMP1 CAR-T cells, a plasmid expressing LMP1 CAR was created using molecular cloning technology, and T cells were infected with LMP1 CAR lentivirus. The effects of LMP1 CAR-T cells on specific cytotoxicity against LMP1-positive tumor cell lines infected with the EB virus had been confirmed. Results: ① LMP1 protein expressing on EB virus-positive lymphoma cells surface was verified. ② The LMP1 CAR-expressing plasmid was created, and LMP1 CAR-T cells were obtained by infecting T cells with a lentivirus packaging system, with an infection efficiency of more than 80% . ③LMP1 CAR-T cells have a 4∶1 effect-to-target ratio in killing LMP1-positive lymphoma cells. The killing effect of LMP1 CAR-T cells on Raji cells was enhanced after 48 h of coculture, but there was no significant killing effect on Ramos, which are LMP1-negative lymphoma cells. ④After coculture with LMP1-positive lymphoma cells at a ratio of 1∶1 for 5 h, the degranulation effect was enhanced. The proportion of CD107a(+) T cells in the LMP1 CAR-T cell treatment group was significantly higher than that in the vector-T cell group [ (13.25±2.94) % vs (1.55±0.05) % , t=3.972, P=0.017]. ⑤After coculture with LMP1-positive lymphoma cells, the proportion of CD69(+) and CD25(+) T cells in the LMP1 CAR-T cell group was significantly higher than that in vector-T cell group [ (7.40±0.41) % vs (3.48±0.47) % , t=6.268, P=0.003; (73.00±4.73) % vs (57.67±2.60) % , t=2.842, P=0.047]. ⑥After coculture with LMP1-positive lymphoma cells, cytokine secretion in the LMP1 CAR-T cell group was higher than that in the vector-T cell group [interferon-gamma: (703±73) ng/L vs (422±87) ng/L, t=2.478, P=0.068; tumor necrosis factor-alpha: (215±35) ng/L vs (125±2) ng/L, t=2.536, P=0.064]. Conclusion: In this study, we found that the LMP1 protein is only found on the surface of the EBV-positive tumor cell. Simultaneously, we created an LMP1 CAR-expressing plasmid and obtained LMP1 CAR-T cells by infecting T cells with a lentivirus packaging system. Furthermore, we demonstrated that LMP1 CAR-T cells could specifically kill LMP1-positive tumor cells in vitro. The degranulation and activation effects of LMP1 CAR-T cells were enhanced after coculture with LMP1-positive tumor cells, indicating a potential clinical application.

Development and functional verification of CAR-T cells targeting CLL-1 / 中华血液学杂志

Objective: To explore the development of a CAR-T cells targeting CLL-1 and verify its function. Methods: The expression levels of CLL-1 targets in cell lines and primary cells were detected by flow cytometry. A CLL-1 CAR vector was constructed, and the corresponding lentivirus was prepared. After infection and activation of T cells, CAR-T cells targeting CLL-1 were produced and their function was verified in vitro and in vivo. Results: CLL-1 was expressed in acute myeloid leukemia (AML) cell lines and primary AML cells. The transduction rate of the prepared CAR T cells was 77.82%. In AML cell lines and AML primary cells, CLL-1-targeting CAR-T cells significantly and specifically killed CLL-1-expressing cells. Compared to untransduced T cells, CAR-T cells killed target cells and secreted inflammatory cytokines, such as interleukin-6 and interferon-γ, at significantly higher levels (P<0.001) . In an in vivo human xenograft mouse model of AML, CLL-1 CAR-T cells also exhibited potent antileukemic activity and induced prolonged mouse survival compared with untransduced T cells [not reached vs 22 days (95%CI 19-24 days) , P=0.002]. Conclusion: CAR-T cells targeting CLL-1 have been successfully produced and have excellent functions.

Phase I study of CBM.CD19 chimeric antigen receptor T cell in the treatment of refractory diffuse large B-cell lymphoma in Chinese patients / 医学前沿

Anti-CD19 chimeric antigen receptor (CAR) T cell therapy has shown impressive efficacy in treating B-cell malignancies. A single-center phase I dose-escalation study was conducted to evaluate the safety and efficacy of T cells transduced with CBM.CD19 CAR, a second-generation anti-CD19 CAR bearing 4-1BB costimulatory molecule, for the treatment of patients with refractory diffuse large B-cell lymphoma (DLBCL). Ten heavily treated patients with refractory DLBCL were given CBM.CD19 CAR-T cell (C-CAR011) treatment. The overall response rate was 20% and 50% at 4 and 12 weeks after the infusion of C-CAR011, respectively, and the disease control rate was 60% at 12 weeks after infusion. Treatment-emergent adverse events occurred in all patients. The incidence of cytokine release syndrome in all grades and grade ⩾ 3 was 90% and 0, respectively, which is consistent with the safety profile of axicabtagene ciloleucel and tisagenlecleucel. Neurotoxicity or other dose-limiting toxicities was not observed in any dose cohort of C-CAR011 therapy. Antitumor efficacy was apparent across dose cohorts. Therefore, C-CAR011 is a safe and effective therapeutic option for Chinese patients with refractory DLBCL, and further large-scale clinical trials are warranted.

Preclinical characterization and comparison between CD3/CD19 bispecific and novel CD3/CD19/CD20 trispecific antibodies against B-cell acute lymphoblastic leukemia: targeted immunotherapy for acute lymphoblastic leukemia / 医学前沿

The CD19-targeting bispecific T-cell engager blinatumomab has shown remarkable efficacy in patients with relapsed/refractory B-cell precursor acute lymphoblastic leukemia. However, several studies showed that blinatumomab has a short plasma half-life due to its low molecular weight, and thus its clinical use is limited. Furthermore, multiple trials have shown that approximately 30% of blinatumomab-relapsed cases are characterized by CD19 negative leukemic cells. Here, we design and characterize two novel antibodies, A-319 and A-2019. Blinatumomab and A-319 are CD3/CD19 bispecific antibodies with different molecular sizes and structures, and A-2019 is a novel CD3/CD19/CD20 trispecific antibody with an additional anti-CD20 function. Our in vitro, ex vivo, and in vivo experiments demonstrated that A-319 and A-2019 are potent antitumor agents and capable of recruiting CD3 positive T cells, enhancing T-cell function, mediating B-cell depletion, and eventually inhibiting tumor growth in Raji xenograft models. The two molecules are complementary in terms of efficacy and specificity profile. The activity of A-319 demonstrated superior to that of A-2019, whereas A-2019 has an additional capability to target CD20 in cells missing CD19, suggesting its potential function against CD19 weak or negative CD20 positive leukemic cells.

Pathological Change of Chronic Hepatitis B Patients with Different Tongue Coatings by Circular Multi-Omics Integrated Analysis / 中国结合医学杂志

OBJECTIVE@#To compare the circular pathological changes of chronic hepatitis B (CHB) patients according to the tongue diagnosis.@*METHODS@#Totally 41 CHB patients with typical white tongue coating (WTC) or yellow tongue coating (YTC) were enrolled and 14 healthy volunteers with normal tongue manifestation served as controls. The mRNA expression of peripheral leukocytes was detected by GeneChips, and 9 genes were randomly selected for expression validation. Circular metabolites were detected by gas chromatographymass spectrometry. Biological information was analyzed based on ingenuity pathways analysis or metabolomics database and the integrated networks were constructed by ClueGO.@*RESULTS@#A total of 945 and 716 differentially expressed genes were found in patients with WTC and YTC relative to healthy volunteers respectively. The biological information analysis indicated that CHB patients had obviously increased functions in cell death, apoptosis and necrosis (Z-score ⩾2, P<0.05) and decreased activation in T lymphocytes (Z-score ⩽-2, P<0.05), regardless of the tongue manifestation. Compared to patients with WTC, the YTC patients were predicted to be more active in functions related to virus replication (Z-score ⩾2, P<0.05), and the content of circular fatty acids, such as oleic acid (P=0.098) and lauric acid (P=0.035), and citric acid cycle-related metabolites were higher in the YTC patients (P<0.1). The integrated analysis based on differential genes and metabolites indicated that the most difference in the biological function network between the WTC and YTC patients was tumor necrosis factor receptor associated factor 6 mediated-nuclear factor kappa-B activation process.@*CONCLUSIONS@#CHB patients with YTC had more severe inflammation and fatty acids metabolism aberrant than patients with WTC. The results facilitate the modern pathological annotation of Chinese medicine tongue diagnosis theory and provide a reference for the interpretation of pharmacological mechanisms of Chinese medicine treatment.

Effect of Dimethyl Fumarate (DMF) on T-cell Acute Lymphoblastic Leukemia / 中国实验血液学杂志

OBJECTIVE@#To explore the effect and possible mechanism of dimethyl fumarate (DMF) on T-cell acute lymphoblastic leukemia (T-ALL), and provide experimental and theoretical basis for the clinical treatment of T-ALL.@*METHODS@#Jurkat cells were treated with different concentrations of DMF for 24 hours, and then the proportion and absolute count of Ki67-positive Jurkat cells were analyzed by flow cytometry. Meanwhile, the protein levels of nuclear factor-erythroid 2-related factor 2 (Nrf2) and E3 ubiquitin ligase HACE1 in Jurkat cells treated with DMF for 24 hours were evaluated by Western blot. Nrf2 proteins were co-immunoprecipitated in Jurkat cells, and then HACE1 protein was assessed by Western blot. Plasmids of Flag-Nrf2 and different gradients of Flag-HACE1 were transfected into HEK293T cells, and the levels of Flag-Nrf2 were detected by Western blot after 48 hours.@*RESULTS@#DMF could significantly inhibit the proportion and absolute count of Ki67-positive Jurkat cells, and DMF inhibited the proliferation of Jurkat cells in a dose-dependent manner (r=0.9595, r=0.9054). DMF could significantly up-regulate the protein levels of Nrf2 and E3 ubiquitin ligase HACE1 in Jurkat cells (P<0.01, P<0.01). HACE1 physically interacted with Nrf2 in Jurkat cells. Overexpression of Flag-HACE1 significantly increased the protein level of Flag-Nrf2 in a dose-dependent manner (r=0.9771).@*CONCLUSION@#DMF inhibits the proliferation of T-cell acute lymphoblastic leukemia cell. The mechanism may be that, DMF significantly up-regulates the protein levels of Nrf2 and E3 ubiquitin ligase HACE1, and HACE1 interacts with Nrf2 and positively regulates Nrf2 protein level.

Metformin and lipopolysaccharide regulate transcription of NFATc2 gene via the transcription factor RUNX2 / 南方医科大学学报

OBJECTIVE@#To construct a luciferase reporter gene vector carrying human nuclear factor of activated T cells 2 (NFATc2) gene promoter and examine the effects of metformin and lipopolysaccharide (LPS) on the transcriptional activity of NFATc2 gene.@*METHODS@#The promoter sequence of human NFATc2 gene was acquired from UCSC website for PCR amplification. NFATc2 promoter fragment was inserted into pGL3-basic plasmid double cleaved with Kpn Ⅰ and Hind Ⅲ. The resultant recombinant plasmid pGL3-NFATC2-promoter was co-transfected with the internal reference plasmid pRL-TK in 293F cells, and luciferase activity in the cells was detected. Reporter gene vectors of human NFATc2 gene promoter with different fragment lengths were also constructed and assayed for luciferase activity. The changes in transcription activity of NFATc2 gene were assessed after treatment with different concentrations of metformin and LPS for 24 h. We also examined the effect of mutation in RUNX2-binding site in NFATC2 gene promoter on the regulatory effects of metformin and LPS on NFATc2 transcription.@*RESULTS@#We successfully constructed pGL3-NFATc2-promoter plasmids carrying different lengths (2170 bp, 2077 bp, 1802 bp, 1651 bp, 1083 bp, 323 bp) of NFATc2 promoter sequences as verified by enzymatic digestion and sequencing. Transfection of 293F cells with the plasmid carrying a 1651 bp NFATc2 promoter (pGL3-1651 bp) resulted in the highest transcriptional activity of NFATc2 gene, and the luciferase activity was approximately 3.3 times that of pGL3-2170 bp (1.843 ± 0.146 vs 0.547 ± 0.085). Moderate (5 mmol/L) and high (10 mmol/L) concentrations of metformin significantly upregulated the transcriptional activity of pGL3-1651 bp by up to 2.5 and 3 folds, respectively. LPS at different doses also upregulated the transcriptional activity of pGL3-1651 bp by at least 1.6 folds. The mutation in the RUNX2 binding site on pGL3-1651 bp obviously reduced metformin- and LPS-induced enhancement of pGL3-1651bp transcription by 1.7 and 2 folds, respectively.@*CONCLUSION@#pGL3-NFATc2-promoter can be transcribed and activated in 293F cells, and LPS and metformin can activate the transcription of pGL3- NFATc2-promoter in a RUNX2-dependent manner.

Role and mechanism of Vγ4 T cells in impaired wound healing of rapamycin-induced full-thickness skin defects in mice / 中华烧伤杂志

Objective: To investigate the role and mechanism of Vγ4 T cells in impaired wound healing of rapamycin-induced full-thickness skin defects in mice. Methods: The experimental research methods were applied. Eighty-six C57BL/6J male mice (hereinafter briefly referred to as wild-type mice) aged 8-12 weeks were selected for the following experiments. Vγ4 T cells were isolated from axillary lymph nodes of five wild-type mice for the following experiments. Intraperitoneal injection of rapamycin for 42 mice was performed to establish rapamycin-treated mice model for the following experiments. Eighteen wild-type mice were divided into normal control group without any treatment, trauma only group, and trauma+CC chemokine ligand 20 (CCL20) inhibitor group according to the random number table (the same grouping method below), with 6 mice in each group. The full-thickness skin defect wound was made on the back of mice in the latter two groups (the same wound model below), and mice in trauma+CCL20 inhibitor group were continuously injected subcutaneously with CCL20 inhibitor at the wound edge for 3 days after injury. Another 6 rapamycin-treated mice were used to establish wound model as rapamycin+trauma group. On post injury day (PID) 3, the epidermal cells of the skin tissue around the wound of each trauma mice were extracted by enzyme digestion, and the percentage of Vγ4 T cells in the epidermal cells was detected by flow cytometry. In normal control group, the epidermal cells of the normal skin tissue in the back of mice were taken at the appropriate time point for detection as above. Five wild-type mice were used to establish wound models. On PID 3, the epidermal cells were extracted from the skin tissue around the wound. The cell populations were divided into Vγ4 T cells, Vγ3 T cells, and γδ negative cells by fluorescence-activated cell sorter, which were set as Vγ4 T cell group, Vγ3 T cell group, and γδ negative cell group (with cells in each group being mixed with B16 mouse melanoma cells), respectively. B16 mouse melanoma cells were used as melanoma cell control group. The expression of interleukin-22 (IL-22) mRNA in cells of each group was detected by real-time fluorescence quantitative reverse transcription polymerase chain reaction (RT-PCR), with the number of samples being 6. Thirty rapamycin-treated mice were used to establish wound models, which were divided into Vγ4 T cell only group and Vγ4 T cell+IL-22 inhibitor group performed with corresponding injections and rapamycin control group injected with phosphate buffer solution (PBS) immediately after injury, with 10 mice in each group. Another 10 wild-type mice were taken to establish wound models and injected with PBS as wild-type control group. Mice in each group were injected continuously for 6 days. The percentage of wound area of mice in the four groups was calculated on PID 1, 2, 3, 4, 5, and 6 after injection on the same day. Six wild-type mice and 6 rapamycin-treated mice were taken respectively to establish wound models as wild-type group and rapamycin group. On PID 3, the mRNA and protein expressions of IL-22 and CCL20 in the peri-wound epidermis tissue of mice in the two groups were detected by real-time fluorescence quantitative RT-PCR and Western blotting, respectively. The Vγ4 T cells were divided into normal control group without any treatment and rapamycin-treated rapamycin group. After being cultured for 24 hours, the mRNA and protein expressions of IL-22 of cells in the two groups were detected by real-time fluorescence quantitative RT-PCR and Western blotting, respectively, with the number of samples being 6. Data were statistically analyzed with independent sample t test, analysis of variance for repeated measurement, one-way analysis of variance, Bonferroni method, Kruskal-Wallis H test, and Wilcoxon rank sum test. Results: The percentage of Vγ4 T cells in the epidermal cells of the skin tissue around the wound of mice in trauma only group on PID 3 was 0.66% (0.52%, 0.81%), which was significantly higher than 0.09% (0.04%, 0.14%) in the epidermal cells of the normal skin tissue of mice in normal control group (Z=4.31, P<0.01). The percentages of Vγ4 T cells in the epidermal cells of the skin tissue around the wound of mice in rapamycin+trauma group and trauma+CCL20 inhibitor group on PID 3 were 0.25% (0.16%, 0.37%) and 0.24% (0.17%, 0.35%), respectively, which were significantly lower than that in trauma only group (with Z values of 2.27 and 2.25, respectively, P<0.05). The mRNA expression level of IL-22 of cells in Vγ4 T cell group was significantly higher than that in Vγ3 T cell group, γδ negative cell group, and melanoma cell control group (with Z values of 2.96, 2.45, and 3.41, respectively, P<0.05 or P<0.01). Compared with that in wild-type control group, the percentage of wound area of mice in rapamycin control group increased significantly on PID 1-6 (P<0.01), the percentage of wound area of mice in Vγ4 T cell+IL-22 inhibitor group increased significantly on PID 1 and PID 3-6 (P<0.05 or P<0.01). Compared with that in rapamycin control group, the percentage of wound area of mice in Vγ4 T cell only group decreased significantly on PID 1-6 (P<0.05 or P<0.01). Compared with that in Vγ4 T cell only group, the percentage of wound area of mice in Vγ4 T cell+IL-22 inhibitor group increased significantly on PID 3-6 (P<0.05 or P<0.01). On PID 3, compared with those in wild-type group, the expression levels of IL-22 protein and mRNA (with t values of -7.82 and -5.04, respectively, P<0.01) and CCL20 protein and mRNA (with t values of -7.12 and -5.73, respectively, P<0.01) were decreased significantly in the peri-wound epidermis tissue of mice in rapamycin group. After being cultured for 24 hours, the expression levels of IL-22 protein and mRNA in Vγ4 T cells in rapamycin group were significantly lower than those in normal control group (with t values of -7.75 and -6.04, respectively, P<0.01). Conclusions: In mice with full-thickness skin defects, rapamycin may impair the CCL20 chemotactic system by inhibiting the expression of CCL20, leading to a decrease in the recruitment of Vγ4 T cells to the epidermis, and at the same time inhibit the secretion of IL-22 by Vγ4 T cells, thereby slowing the wound healing rate.