Peptide: MHC-based DNA vaccination strategy to activate natural killer cells by targeting killer cell immunoglobulin-like receptors

Abstract

BackgroundNatural killer (NK) cells are increasingly being recognized as agents for cancer immunotherapy. The killer cell immunoglobulin-like receptors (KIRs) are expressed by NK cells and are immunogenetic determinants of the outcome of cancer. In particular, KIR2DS2 is associated with protective responses to several cancers and also direct recognition of cancer targets in vitro. Due to the high homology between activating and inhibitory KIR genes to date, it has been challenging to target individual KIR for therapeutic benefit.MethodsA novel KIR2DS2-targeting therapeutic peptide:MHC DNA vaccine was designed and used to immunize mice transgenic for KIR genes (KIR-Tg). NK cells were isolated from the livers and spleens of vaccinated mice and then analyzed for activation by flow cytometry, RNA profiling and cytotoxicity assays. In vivo assays of NK cell function using a syngeneic cancer model (B16 melanoma) and an adoptive transfer model for human hepatocellular carcinoma (Huh7) were performed.ResultsInjecting KIR-Tg mice with the vaccine construct activated NK cells in both liver and spleens of mice, with preferential activation of KIR2DS2-positive NK cells. KIR-specific activation was most marked on the CD11b+CD27+ mature subset of NK cells. RNA profiling indicated that the DNA vaccine upregulated genes associated with cellular metabolism and downregulated genes related to histone H3 methylation, which are associated with immune cell maturation and NK cell function. Vaccination led to canonical and cross-reactive peptide:MHC-specific NK cell responses. In vivo, DNA vaccination led to enhanced antitumor responses against B16F10 melanoma cells and also enhanced responses against a tumor model expressing the KIR2DS2 ligand HLA-C*0102.ConclusionWe show the feasibility of a peptide-based KIR-targeting vaccine strategy to activate NK cells and hence generate functional antitumor responses. This approach does not require detailed knowledge of the tumor peptidomes nor HLA matching with the patient. It therefore offers a novel opportunity for targeting NK cells for cancer immunotherapy.

Relevance of Polymorphic KIR and HLA Class I Genes in NK-Cell-Based Immunotherapies for Adult Leukemic Patients

“…KIR2DS2 recognizes C1 ligands and the HLA-A11 molecule [87,88]. As reported for KIR2DL2/3, the recognition of KIR2DS2 of HLA-C molecules is peptide-dependent [88,89]. KIR2DS4 recognizes some HLA-C molecules and the HLA-A11 molecule [90].…”

Peanut oral immunotherapy: current trends in clinical trials

“…The ARA-LAMP-vax (Immunomic Therapeutics Inc., Pennsylvania, USA) comprises one DNA plasmid encoding the major peanut allergens Ara h 1, Ara h 2, and Ara h 3, encoded as fusion proteins with lysosomal associated membrane protein (LAMP) [ 44 ]. Immunomic therapeutics hypothesise that this plasmid DNA vaccination is a strategy to activate natural killer (NK) cells that produce interferon-gamma (IFNγ) [ 45 ], influencing skewing of Th cell responses. The LAMP technology diverts the synthesised Ara h protein products of the vaccine directly to the lysosome in the dendritic cells, making them readily available to form antigen-MHC-II complexes.…”

“…The LAMP technology diverts the synthesised Ara h protein products of the vaccine directly to the lysosome in the dendritic cells, making them readily available to form antigen-MHC-II complexes. Once on the cell surface, these MHC-II complexes can directly interact with Th cells and in the presence of IFNγ, lead to the production of antibodies and Th1 cytokines [ 45 , 46 ]. Trial completion is anticipated by the end of 2021, and results will inform treatment safety and whether the immune response could be redirected from a Th2/IgE allergen-specific response to a Th1/IgG response.…”

Combination of Ablation and Immunotherapy for Hepatocellular Carcinoma: Where We Are and Where to Go

“…For instance, Liao et al successfully applied NIR-II fluorescent imaging to NK cell-based immunotherapy for the realtime quantitative tracking and visualization of the viability of adoptive NK cells in vivo (119). The potency of immunotherapies can be enhanced by modification with specific antigens (120)(121)(122), mRNA optimization (123) and combination with adjuvants (124,125).…”