Generation of high-affinity CMV-specific T cells for adoptive immunotherapy using IL-2, IL-15, and IL-21

Multidimensional evaluation of CMV-specific T Cells: enhancing therapy through transcriptional insights

Adoptive immunotherapy with CMV-specific T cells (CMV-VSTs) has shown favorable efficacy and minimal adverse effects in clinical settings, serving as prophylaxis, preemptive and/or curative treatment for the restoration of CMV-specific immunity in patients after allogeneic hematopoietic stem cell transplantation. The establishment of a CMV-VST bank enables the prompt use of CMV-VSTs as off-the-shelf therapeutics. CMV-VSTs can be generated through cell culture or immunomagnetic selection based on IFN-γ secretion or multimer technology. In this study, we investigated the feasibility of generating CMV-VSTs via cell expansion after IFN-γ based immunomagnetic isolation, with the goal of establishing a good-quality, cost-effective local production approach. We also assessed the value of incorporating transcriptomic analysis into the current T cell evaluation framework. Our results demonstrate that good-quality CMV-VSTs can be produced using either autologous feeder cells or feeder cells from the rapid expansion protocol (REP), in combination with cytokines such as IL-2 or IL-7/IL-15. Phenotypic and functional analyses confirmed the consistent quality of the final T cell products and showed no significant differences across the various combinations of feeder cells and cytokines. However, transcriptomic analysis highlighted the advantages of using IL-7/IL-15 and autologous feeder cells. Collectively, our findings offer new insights into future strategies for the manufacturing of antigen-specific T cells and underscore the importance of comprehensive, multidimensional assessment in T cell-based immunotherapies.

Hudgens M, Goonetilleke NP. CD3 downregulation identifies high-avidity human CD8 T cells

CD8 T cells recognize infected and cancerous cells via their T-cell receptor (TCR), which binds peptide-MHC complexes on the target cell. The affinity of the interaction between the TCR and peptide-MHC contributes to the antigen sensitivity, or functional avidity, of the CD8 T cell. In response to peptide-MHC stimulation, the TCR-CD3 complex and CD8 co-receptor are downmodulated. We quantified CD3 and CD8 downmodulation following stimulation of human CD8 T cells with CMV, EBV, and HIV peptides spanning eight MHC restrictions, observing a strong correlation between the levels of CD3 and CD8 downmodulation and functional avidity, regardless of peptide viral origin. In TCR-transduced T cells targeting a tumor-associated antigen, changes in TCR-peptide affinity were sufficient to modify CD3 and CD8 downmodulation. Correlation analysis and generalized linear modeling indicated that CD3 downmodulation was the stronger correlate of avidity. CD3 downmodulation, simply measured using flow cytometry, can be used to identify high-avidity CD8 T cells in a clinical context.

Tumor-infiltrating lymphocytes mediate complete and durable remission in a patient with NY-ESO-1 expressing prostate cancer

Adoptive transfer of autologous tumor-specific lymphocytes represents a viable treatment method for patients with advanced malignancies. Here, we report a patient's case with metastatic hormone-refractory New York esophageal squamous cell carcinoma 1 (NY-ESO-1) expressing prostate cancer treated with in vitro expanded tumor-infiltrating lymphocytes (TILs) in conjunction with IL-2 and immune-checkpoint blockade. Complete and durable tumor remission was observed after three TIL infusions consisting of 1.4×10⁹, 2.0×10⁹, and 8.0×10⁹ T cells, respectively, lasting now for more than 3.5 years. Immunological correlates to the clinical development were the decrease of tumor-driven NY-ESO-1 serum antibody and the drop of prostate-specific antigen to <0.01 µg/L. TILs were reactive against cancer-testis antigen NY-ESO-1, individual tumor mutational proteins (eg, PRPF8, TRPS1), and the androgen receptor splice variant 12.

The Basis and Advances in Clinical Application of Cytomegalovirus-Specific Cytotoxic T Cell Immunotherapy for Glioblastoma Multiforme

A high percentage of malignant gliomas are infected by human cytomegalovirus (HCMV), and the endogenous expression of HCMV genes and their products are found in these tumors. HCMV antigen expression and its implications in gliomagenesis have emerged as a promising target for adoptive cellular immunotherapy (ACT) strategies in glioblastoma multiforme (GB) patients. Since antigen-specific T cells in the tumor microenvironments lack efficient anti-tumor immune response due to the immunosuppressive nature of glioblastoma, CMV-specific ACT relies on in vitro expansion of CMV-specific CD8+ T cells employing immunodominant HCMV antigens. Given the fact that several hurdles remain to be conquered, recent clinical trials have outlined the feasibility of CMV-specific ACT prior to tumor recurrence with minimal adverse effects and a substantial improvement in median overall survival and progression-free survival. This review discusses the role of HCMV in gliomagenesis, disease prognosis, and recent breakthroughs in harnessing HCMV-induced immunogenicity in the GB tumor microenvironment to develop effective CMV-specific ACT.

Egg Allergy: Diagnosis and Immunotherapy

Hypersensitivity or an allergy to chicken egg proteins is a predominant symptomatic condition affecting 1 in 20 children in Australia; however, an effective form of therapy has not yet been found. This occurs as the immune system of the allergic individual overreacts when in contact with egg allergens (egg proteins), triggering a complex immune response. The subsequent instantaneous inflammatory immune response is characterized by the excessive production of immunoglobulin E (IgE) antibody against the allergen, T-cell mediators and inflammation. Current allergen-specific approaches to egg allergy diagnosis and treatment lack consistency and therefore pose safety concerns among anaphylactic patients. Immunotherapy has thus far been found to be the most efficient way to treat and relieve symptoms, this includes oral immunotherapy (OIT) and sublingual immunotherapy (SLIT). A major limitation in immunotherapy, however, is the difficulty in preparing effective and safe extracts from natural allergen sources. Advances in molecular techniques allow for the production of safe and standardized recombinant and hypoallergenic egg variants by targeting the IgE-binding epitopes responsible for clinical allergic symptoms. Site-directed mutagenesis can be performed to create such safe hypoallergens for their potential use in future methods of immunotherapy, providing a feasible standardized therapeutic approach to target egg allergies safely.