Single-cell profiling identifies a novel human polyclonal unconventional T cell lineage

Neoantigen-targeted dendritic cell vaccination in lung cancer patients induces long-lived T cells exhibiting the full differentiation spectrum

Non-small cell lung cancer (NSCLC) is known for high relapse rates despite resection in early stages. Here, we present the results of a phase I clinical trial in which a dendritic cell (DC) vaccine targeting patient-individual neoantigens is evaluated in patients with resected NSCLC. Vaccine manufacturing is feasible in six of 10 enrolled patients. Toxicity is limited to grade 1-2 adverse events. Systemic T cell responses are observed in five out of six vaccinated patients, with T cell responses remaining detectable up to 19 months post vaccination. Single-cell analysis indicates that the responsive T cell population is polyclonal and exhibits the near-entire spectrum of T cell differentiation states, including a naive-like state, but excluding exhausted cell states. Three of six vaccinated patients experience disease recurrence during the follow-up period of 2 years. Collectively, these data support the feasibility, safety, and immunogenicity of this treatment in resected NSCLC.

Cancer immunity by tissue-resident type 1 innate lymphoid cells and killer innate-like T cells

Cancer progression can be restrained by tumor-infiltrating lymphocytes in a process termed cancer immunosurveillance. Based on how lymphocytes are activated and recruited to the tumor tissue, cancer immunity is either pre-wired, in which innate lymphocytes and innate-like T cells are directly recruited to and activated in tumors following their differentiation in primary lymphoid organs; or priming-dependent, in which conventional adaptive T cells are first primed by cognate antigens in secondary lymphoid organs before homing to and reactivated in tumors. While priming-dependent cancer immunity has been a focus of cancer immunology research for decades, in part due to historical preconception of cancer theory and tumor model choice as well as clinical success of conventional adaptive T cell-directed therapeutic programs, recent studies have revealed that pre-wired cancer immunity mediated by tissue-resident type 1 innate lymphoid cells (ILC1s) and killer innate-like T cells (ILTCKs) is an integral component of the cancer immunosurveillance process. Herein we review the distinct ontogenies and cancer-sensing mechanisms of ILC1s and ILTCKs in murine genetic cancer models as well as the conspicuously conserved responses in human malignancies. How ILC1s and ILTCKs may be targeted to broaden the scope of cancer immunotherapy beyond conventional adaptive T cells is also discussed.

HELIOS-expressing human CD8 T cells exhibit limited effector functions

Introduction

The transcription factor HELIOS is primarily known for its expression in CD4 regulatory T cells, both in humans and mice. In mice, HELIOS is found in exhausted CD8 T cells. However, information on human HELIOS+ CD8 T cells is limited and conflicting.

Methods

In this study, we characterized by flow cytometry and transcriptomic analyses human HELIOS+ CD8 T cells.

Results

These T cells primarily consist of memory cells and constitute approximately 21% of blood CD8 T cells. In comparison with memory HELIOS- T-BEThigh CD8 T cells that displayed robust effector functions, the memory HELIOS+ T-BEThigh CD8 T cells produce lower amounts of IFN-γ and TNF-α and have a lower cytotoxic potential. We wondered if these cells participate in the immune response against viral antigens, but did not find HELIOS+ cells among CD8 T cells recognizing CMV peptides presented by HLA-A2 and HLA-B7. However, we found HELIOS+ CD8 T cells that recognize a CMV peptide presented by MHC class Ib molecule HLA-E. Additionally, a portion of HELIOS+ CD8 T cells is characterized by the expression of CD161, often used as a surface marker for identifying TC17 cells. These CD8 T cells express TH17/TC17-related genes encoding RORgt, RORa, PLZF, and CCL20.

Discussion

Our findings emphasize that HELIOS is expressed across various CD8 T cell populations, highlighting its significance beyond its role as a transcription factor for Treg or exhausted murine CD8 T cells. The significance of the connection between HELIOS and HLA-E restriction is yet to be understood.

Early innate role for CD8αα+ cells in tuberculosis

Cell types that mediate early control of Mycobacterium tuberculosis (Mtb) infection are not well understood. Winchell and Nyquist et al. (https://doi.org/10.1084/jem.20230707) show that CD8αα+ lymphocytes have a major role in the innate suppression of Mtb growth in the lungs of macaques.