HLA class II restricted T-cell receptor gene transfer generates CD4+ T cells with helper activity as well as cytotoxic capacity

Both cytotoxic T cells and helper T cells are important in immune responses against pathogens and malignant cells. In hematological malignancies which express HLA class II molecules, immunotherapy may be directed to HLA class II restricted antigens. We investigated whether it is possible to engineer HLA class II restricted T cells with both antigen-specific cytolytic activity and the capacity to produce high amounts of cytokines. CD4+ and CD8+ peripheral-blood-derived T cells were retrovirally transduced with the HLA class II restricted minor histocompatibility antigen dead box RNA helicase Y (DBY)-specific TCR. The TCR-transduced CD4+ T cells exerted DBY-specific cytolytic activity, produced Th0, Th1, or Th2 cytokines, and proliferated upon DBY-specific stimulation. TCR-transduced CD8+ T cells exerted cytolytic activity which equaled the level of cytolytic activity of the TCR-transferred CD4+ T cells. Cotransfer of CD4 enhanced the cytolytic activity of the TCR-transduced CD8+ T cells, but introduction of CD4 was not sufficient to generate DBY-specific CD8+ T cells with the capacity to produce high amounts of cytokines. In this study, we demonstrated the feasibility to engineer T cells with antigen-specific cytolytic activity, as well as the ability to produce significant amounts of cytokines, by TCR transfer to CD4+ T cells.

Array CGH in human leukemia: from somatics to genetics

During the past decade, array CGH has been applied to study copy number alterations in the genome in human leukemia in relation to prediction of prognosis or responsiveness to therapy. In the first segment of this review, we will focus on the identification of acquired mutations by array CGH, followed by studies on the pathogenesis of leukemia associated with germline genetic variants, phenotypic presentation and response to treatment. In the last section, we will discuss constitutional genomic aberrations causally related to myeloid leukemogenesis.

Prolonged Disease Course of COVID-19 in a Patient with CTLA-4 Haploinsufficiency

Patients with primary immunodeficiencies are especially vulnerable to developing severe coronavirus disease 2019 (COVID-19) after infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Cytotoxic T lymphocyte antigen-4 (CTLA-4) is an important regulator of immune responses, and patients who suffer from CTLA4 haploinsufficiency have hyperactivation of effector T cells and infiltration of various organs. Overexpression of CTLA4 has been associated with a more severe disease course in patients with COVID-19, but there have only been a few reports on the disease course of COVID-19 in patients with CTLA4 haploinsufficiency. We report on a 33-year-old female with a history of immune thrombocytopenia, autoimmune haemolytic anaemia, granulomatous-lymphocytic interstitial lung disease, and common variable immunodeficiency who developed COVID-19. She was admitted and discharged from the hospital several times in the months thereafter and remained symptomatic and had a positive SARS-CoV-2 PCR for up to 137 days after the first symptoms. No SARS-CoV-2 antibodies were identified in the patients' serum. The disease was finally controlled after repeated infusions of convalescent plasma and treatment of concurrent bacterial and fungal infections. Genetic analysis revealed a likely pathogenic variant in CTLA4, and CTLA4 expression on regulatory T-cells was low. This case illustrates that patients with primary immunodeficiencies who have a protracted disease course of COVID-19 could benefit from convalescent plasma therapy.