CD30 plays a role in T-dependent immune response and T cell proliferation

CD30 is a member of the tumor necrosis factor receptor (TNFR) superfamily and expressed in both normal and malignant lymphoid cells. However, the role of CD30 in lymphopoiesis is not known. In this study, we showed CD30 was expressed both in T and B cells, but its deficiency in mice had no effect on T- and B-cell development. In fact, CD30 deficiency attenuated B-cell response to T-cell-dependent antigens. The impaired B cell response in CD30-deficient mice is caused by the reduction of activation-induced cytidine deaminase (AID) expression. Moreover, CD30-deficient mice exhibited decreased TCR-mediated T cell proliferation and slightly impaired TCR signaling. High-throughput RNA sequencing analysis revealed that CD30 deficiency led to a decrease of FOXO-autophagy axis in T cells upon TCR stimulation. Thus, CD30 positively regulates T-cell-dependent immune response and T cell proliferation.

CAR-T Cell Therapy for Classical Hodgkin Lymphoma

Classical Hodgkin lymphoma (cHL) is a malignancy characterized by the presence of Hodgkin and Reed-Sternberg (HRS) cells within a complex tumor microenvironment (TME). Despite advances in conventional therapies, a subset of cHL patients experience relapse or refractory disease, necessitating the exploration of novel treatment strategies. Chimeric antigen receptor T cell (CAR-T cell) therapy has emerged as a promising approach for the management of cHL, harnessing the power of genetically modified T cells to recognize and eliminate tumor cells. In this article, we provide an overview of the pathogenesis of cHL, highlighting the key molecular and cellular mechanisms involved. Additionally, we discuss the rationale for the development of CAR-T cell therapy in cHL, focusing on the identification of suitable targets on HRS cells (such as CD30, CD123, LMP1, and LMP2A), clonotypic lymphoma initiating B cells (CD19, CD20), and cells within the TME (CD123, CD19, CD20) for CAR-T cell design. Furthermore, we explore various strategies employed to enhance the efficacy and safety of CAR-T cell therapies in the treatment of cHL. Finally, we present an overview of the results obtained from clinical trials evaluating the efficacy of CAR-T cell therapies in cHL, highlighting their potential as a promising therapeutic option. Collectively, this article provides a comprehensive review of the current understanding of cHL pathogenesis and the rationale for CAR-T cell therapy development, offering insights into the future directions of this rapidly evolving field.

In vitro differentiated human CD4+ T cells produce hepatocyte growth factor

Differentiation of naive CD4⁺ T cells into effector T cells is a dynamic process in which the cells are polarized into T helper (Th) subsets. The subsets largely consist of four fundamental categories: Th1, Th2, Th17, and regulatory T cells. We show that human memory CD4⁺ T cells can produce hepatocyte growth factor (HGF), a pleiotropic cytokine which can affect several tissue types through signaling by its receptor, c-Met. In vitro differentiation of T cells into Th-like subsets revealed that HGF producing T cells increase under Th1 conditions. Enrichment of HGF producing cells was possible by targeting cells with surface CD30 expression, a marker discovered through single-cell RNA-sequencing. Furthermore, pharmacological inhibition of PI3K or mTOR was found to inhibit HGF mRNA and protein, while an Akt inhibitor was found to increase these levels. The findings suggest that HGF producing T cells could play a role in disease where Th1 are present.

LCL161 enhances expansion and survival of engineered anti-tumor T cells but is restricted by death signaling

Background

The genesis of SMAC mimetic drugs is founded on the observation that many cancers amplify IAP proteins to facilitate their survival, and therefore removal of these pathways would re-sensitize the cells towards apoptosis. It has become increasingly clear that SMAC mimetics also interface with the immune system in a modulatory manner. Suppression of IAP function by SMAC mimetics activates the non-canonical NF-κB pathway which can augment T cell function, opening the possibility of using SMAC mimetics to enhance immunotherapeutics.

Methods

We have investigated the SMAC mimetic LCL161, which promotes degradation of cIAP-1 and cIAP-2, as an agent for delivering transient costimulation to engineered BMCA-specific human TAC T cells. In doing so we also sought to understand the cellular and molecular effects of LCL161 on T cell biology.

Results

LCL161 activated the non-canonical NF-κB pathway and enhanced antigen-driven TAC T cell proliferation and survival. Transcriptional profiling from TAC T cells treated with LCL161 revealed differential expression of costimulatory and apoptosis-related proteins, namely CD30 and FAIM3. We hypothesized that regulation of these genes by LCL161 may influence the drug's effects on T cells. We reversed the differential expression through genetic engineering and observed impaired costimulation by LCL161, particularly when CD30 was deleted. While LCL161 can provide a costimulatory signal to TAC T cells following exposure to isolated antigen, we did not observe a similar pattern when TAC T cells were stimulated with myeloma cells expressing the target antigen. We questioned whether FasL expression by myeloma cells may antagonize the costimulatory effects of LCL161. Fas-KO TAC T cells displayed superior expansion following antigen stimulation in the presence of LCL161, suggesting a role for Fas-related T cell death in limiting the magnitude of the T cell response to antigen in the presence of LCL161.

Conclusions

Our results demonstrate that LCL161 provides costimulation to TAC T cells exposed to antigen alone, however LCL161 did not enhance TAC T cell anti-tumor function when challenged with myeloma cells and may be limited due to sensitization of T cells towards Fas-mediated apoptosis.

CD30 Overexpression Enhances Negative Selection in the Thymus and Mediates Programmed Cell Death Via a Bcl-2-Sensitive Pathway

The biological function of CD30 in the thymus has been only partially elucidated, although recent data indicate that it may be involved in negative selection. Because CD30 is expressed only by a small subpopulation of medullary thymocytes, we generated transgenic (Tg) mice overexpressing CD30 in T lymphocytes to further address its role in T cell development. CD30 Tg mice have normal thymic size with a normal number and subset distribution of thymocytes. In vitro, in the absence of CD30 ligation, thymocytes of CD30 Tg mice have normal survival and responses to apoptotic stimuli such as radiation, dexamethasone, and Fas. However, in contrast to controls, CD30 Tg thymocytes are induced to undergo programmed cell death (PCD) upon cross-linking of CD30, and the simultaneous engagement of TCR and CD30 results in a synergistic increase in thymic PCD. CD30-mediated PCD requires caspase 1 and caspase 3, is not associated with the activation of NF-κB or c-Jun, but is totally prevented by Bcl-2. Furthermore, CD30 overexpression enhances the deletion of CD4+/CD8+ thymocytes induced by staphylococcal enterotoxin B superantigen and specific peptide. These findings suggest that CD30 may act as a costimulatory molecule in thymic negative selection.