Artificial antigen-presenting cells plus IL-15 and IL-21 efficiently induce melanoma-specific cytotoxic CD8+ CD28+ T lymphocyte responses

Human papilloma virus-specific T cells can be generated from naïve T cells for use as an immunotherapeutic strategy for immunocompromised patients

Human papilloma virus (HPV) is a known cause of cervical cancer, squamous cell carcinoma and laryngeal cancer. Although treatments exist for HPV-associated malignancies, patients unresponsive to these therapies have a poor prognosis. Recent findings from vaccine studies suggest that T-cell immunity is essential for disease control. Because Epstein-Barr Virus (EBV)-specific T cells have been highly successful in treating or preventing EBV-associated tumors, we hypothesized that the development of a manufacturing platform for HPV-specific T cells from healthy donors could be used in a third-party setting to treat patients with high-risk/relapsed HPV-associated cancers. Most protocols for generating virus-specific T cells require prior exposure of the donor to the targeted virus and, because the seroprevalence of high-risk HPV types varies greatly by age and ethnicity, manufacturing of donor-derived HPV-specific T cells has proven challenging. We, therefore, made systematic changes to our current Good Manufacturing Practice (GMP)-compliant protocols to improve antigen presentation, priming and expansion for the manufacture of high-efficacy HPV-specific T cells. Like others, we found that current methodologies fail to expand HPV-specific T cells from most healthy donors. By optimizing dendritic cell maturation and function with lipopolysaccharide (LPS) and interferon (IFN)γ, adding interleukin (IL)-21 during priming and depleting memory T cells, we achieved reliable expansion of T cells specific for oncoproteins E6 and E7 to clinically relevant amounts (mean, 578-fold expansion; n = 10), which were polyfunctional based on cytokine multiplex analysis. In the third-party setting, such HPV-specific T-cell products might serve as a potent salvage therapy for patients with HPV-associated diseases.

Biomaterials-Based Vaccination Strategies for the Induction of CD8+T Cell Responses

Natural and synthetic biomaterials are increasingly being used for the development of vaccines and immunotherapies as alternatives to traditional live-attenuated formulations due to their improved safety profiles and no risk of reversion to virulence. Polymeric materials in particular enjoy attention due to the ease of fabrication, control over physicochemical properties, and their wide range of immunogenicity. While the majority of studies focus on inducing protective antibody responses, in recent years, materials-based strategies for the delivery of antigens and immunomodulators to improve CD8⁺T cell immunity against infectious and non-infectious diseases have gained momentum. Notably, platforms based on polymeric nanoparticles, liposomes, micelles, virus-like particles, self-assembling peptides and peptidomimetics, and multilayer thin films show considerable promise in preclinical studies. In this Review, we first introduce the concepts of CD8⁺T cell activation, effector and memory functions, and cytotoxic activity, followed by vaccine design for eliciting robust and protective long-lived CD8⁺T cell immunity. We then discuss different materials-based vaccines developed in the past decade to elicit CD8⁺T cell responses based on molecular composition or fabrication methods and conclude with a summary and glimpse at the future trends in this area.

Folate-modified Chitosan Nanoparticles Containing the IP-10 Gene Enhance Melanoma-specific Cytotoxic CD8(+)CD28(+) T Lymphocyte Responses

BACKGROUND

Adoptive immunotherapy with cytotoxic T lymphocytes (CTLs) has great potential for the treatment of some malignant cancers. Therefore, augmenting the responses of tumor-specific CTLs is significant for the adoptive immunotherapy of melanoma. This study aimed to investigate the anti-tumor response of a combination therapy employing folate-modified chitosan nanoparticles containing IP-10 (interferon-γ-inducible protein-10) plus melanoma TRP2-specific CD8(+)CD28(+) T cells.

METHODS

We prepared folate-modified chitosan nanoparticles containing the mouse IP-10 gene (FA-CS-mIP-10), and induced melanoma TRP2-specific CD8(+)CD28(+) T cells by co-culturing them with artificial antigen-presenting cells. B16-bearing mice were treated with FA-CS-mIP-10, melanoma TRP2-specific CD8(+)CD28(+) T cells, a combination of both, and the saline control. Tumor volumes and the survival time of mice were recorded. The proportion of myeloid-derived suppressor cells (MDSCs) infiltrating the tumor microenvironment and regulatory T cells (Tregs) in the spleen was analyzed by flow cytometry. We also detected the proliferation and angiogenesis of tumors by immunohistochemistry and apoptosis by TUNEL.

RESULTS

The combination therapy inhibited the progression of melanoma in vivo. Compared with other treatments, it more efficiently inhibited tumor growth and increased the survival time of mice. After treatment with combination therapy, the proportion of MDSCs and Tregs decreased, while the percentage of CXCR3(+)CD8(+) T cells increased. Furthermore, combination therapy inhibited proliferation and promoted apoptosis of tumor cells and significantly inhibited tumor angiogenesis in vivo.

CONCLUSION

We describe a novel strategy for improving the anti-tumor response of CD8(+)CD28(+) CTLs by combining them with FA-CS-mIP-10 nanoparticles.

IL-15 functions as a danger signal to regulate tissue-resident T cells and tissue destruction

In this Opinion article, we discuss the function of tissues as a crucial checkpoint for the regulation of effector T cell responses, and the notion that interleukin-15 (IL-15) functions as a danger molecule that communicates to the immune system that the tissue is under attack and poises it to mediate tissue destruction. More specifically, we propose that expression of IL-15 in tissues promotes T helper 1 cell-mediated immunity and provides co-stimulatory signals to effector cytotoxic T cells to exert their effector functions and drive tissue destruction. Therefore, we think that IL-15 contributes to tissue protection by promoting the elimination of infected cells but that when its expression is chronically dysregulated, it can promote the development of complex T cell-mediated disorders associated with tissue destruction, such as coeliac disease and type 1 diabetes.

Towards efficient cancer immunotherapy: advances in developing artificial antigen-presenting cells

Active anti-cancer immune responses depend on efficient presentation of tumor antigens and co-stimulatory signals by antigen-presenting cells (APCs). Therapy with autologous natural APCs is costly and time-consuming and results in variable outcomes in clinical trials. Therefore, development of artificial APCs (aAPCs) has attracted significant interest as an alternative. We discuss the characteristics of various types of acellular aAPCs, and their clinical potential in cancer immunotherapy. The size, shape, and ligand mobility of aAPCs and their presentation of different immunological signals can all have significant effects on cytotoxic T cell activation. Novel optimized aAPCs, combining carefully tuned properties, may lead to efficient immunomodulation and improved clinical responses in cancer immunotherapy.