Immunophenotypic characterization of TCR γδ T cells and MAIT cells in HIV-infected individuals developing Hodgkin's lymphoma

Tumor-Immune Signatures of Treatment Resistance to Brentuximab Vedotin with Ipilimumab and/or Nivolumab in Hodgkin Lymphoma

To investigate the cellular and molecular mechanisms associated with targeting CD30-expressing Hodgkin lymphoma (HL) and immune checkpoint modulation induced by combination therapies of CTLA4 and PD1, we leveraged Phase 1/2 multicenter open-label trial NCT01896999 that enrolled patients with refractory or relapsed HL (R/R HL). Using peripheral blood, we assessed soluble proteins, cell composition, T-cell clonality, and tumor antigen-specific antibodies in 54 patients enrolled in the phase 1 component of the trial. NCT01896999 reported high (>75%) overall objective response rates with brentuximab vedotin (BV) in combination with ipilimumab (I) and/or nivolumab (N) in patients with R/R HL. We observed a durable increase in soluble PD1 and plasmacytoid dendritic cells as well as decreases in plasma CCL17, ANGPT2, MMP12, IL13, and CXCL13 in N-containing regimens (BV + N and BV + I + N) compared with BV + I (P < 0.05). Nonresponders and patients with short progression-free survival showed elevated CXCL9, CXCL13, CD5, CCL17, adenosine-deaminase, and MUC16 at baseline or after one treatment cycle and a higher prevalence of NY-ESO-1-specific autoantibodies (P < 0.05). The results suggest a circulating tumor-immune-derived signature of BV ± I ± N treatment resistance that may be useful for patient stratification in combination checkpoint therapy.

SIGNIFICANCE

Identification of multi-omic immune markers from peripheral blood may help elucidate resistance mechanisms to checkpoint inhibitor and antibody-drug conjugate combinations with potential implications for treatment decisions in relapsed HL.

Immune characteristics and prognostic implications of mucosal-associated invariant T cells in acute myeloid leukemia

Increasing evidence suggests that mucosal-associated invariant T cells (MAITs) play a crucial role in anti-tumor responses against various cancers. In this study, we investigated the immune characteristics of MAIT cells in patients with acute myeloid leukemia (AML). Using multi-parameter flow cytometry, we performed phenotypic and functional analysis of MAITs in peripheral blood or bone marrow samples collected from 131 patients with AML including 99 newly diagnosed, 18 remission, and 14 relapsed cases, as well as 69 healthy controls. We found that MAITs exhibit signs of aging and exhaustion, particularly in CD8+ MAITs subset, at newly diagnosis. MAITs exhibit an effector memory or terminally differentiated phenotype. Frequency and number of MAITs reflect AML cell genetic features, tumor burden, disease status, and treatment responsiveness. Moreover, MAITs exhibit a highly activated or even exhausted state, as indicated by upregulation of PD-1. Furthermore, impaired production of Th1-type cytokines and increased secretion of Th17-type cytokines, granzyme B, and perforin were observed in MAITs from AML patients. Additionally, MAITs shifted toward producing cytokines that promote tumor progression, such as IL-8. Lower frequency of MAITs was associated with poorer overall survival (OS), and multivariate analysis revealed that MAITs frequency < 2.12% was an independent prognostic factor affecting OS. Collectively, our findings suggest that MAITs may play a role in immune deficiency in AML, emphasizing their potential importance in AML pathogenesis and treatment. These discoveries provide a theoretical basis for the development of novel immunotherapeutic strategies in AML.

γδ T cells in immunotherapies for B-cell malignancies

Despite the advancements in therapy for B cell malignancies and the increase in long-term survival of patients, almost half of them lead to relapse. Combinations of chemotherapy and monoclonal antibodies such as anti-CD20 leads to mixed outcomes. Recent developments in immune cell-based therapies are showing many encouraging results. γδ T cells, with their potential of functional plasticity and their anti-tumoral properties, emerged as good candidates for cancer immunotherapies. The representation and the diversity of γδ T cells in tissues and in the blood, in physiological conditions or in B-cell malignancies such as B cell lymphoma, chronic lymphoblastic leukemia or multiple myeloma, provides the possibility to manipulate them with immunotherapeutic approaches for these patients. In this review, we summarized several strategies based on the activation and tumor-targeting of γδ T cells, optimization of expansion protocols, and development of gene-modified γδ T cells, using combinations of antibodies and therapeutic drugs and adoptive cell therapy with autologous or allogenic γδ T cells following potential genetic modifications.

Double-negative T cells: Setting the stage for disease control or progression

Double-negative (DN) T cells are present at relatively low frequencies in human peripheral blood, and are characterized as expressing the alpha-beta or gamma-delta T-cell receptor (TCR), but not the CD4 nor the CD8 co-receptors. Despite their low frequencies, these cells are potent producers of cytokines and, thus, are key orchestrators of immune responses. DN T cells were initially associated with induction of peripheral immunological tolerance and immunomodulatory activities related to disease prevention. However, other studies demonstrated that these cells can also display effector functions associated with pathology development. This apparent contradiction highlighted the heterogeneity of the DN T-cell population. Here, we review phenotypic and functional characteristics of DN T cells, emphasizing their role in human diseases. The need for developing biomarkers to facilitate the translation of studies from animal models to humans will also be discussed. Finally, we will examine DN T cells as promising therapeutic targets to prevent or inhibit human disease development.