Recent findings about the new roles of lactate have changed our understanding of this end product of glycolysis or fermentation that was once considered only a waste product. It is now well accepted that lactate acts as a signaling molecule and fuel source for cancer cells in a glucose-restricted environment. Moreover, lactate and lactate dehydrogenase are markers of poor prognosis of many cancers and regulate many functions of immune cells. The presence of lactate in the tumor microenvironment (TME) leads to polarization of the immunosuppressive phenotypes of dendritic cells and impairs the cytotoxic abilities of T cells and NK cells, and as such lactate is a major obstacle to immune-cell effector functions and the efficacy of cell-based immunotherapies. Emerging evidence suggests that lactate in the TME might be a novel therapeutic target to enhance the immunotherapeutic potential of cell-based therapies. This review describes our current understanding of the role of lactate in tumor biology, including its detrimental effects on cell-based immunotherapy in cancer. We also highlight how the role of lactate in the TME must be considered when producing cell therapies designed for adoptive transfer and describe how targeted modulation of lactate in the TME might boost immune-cell functions and positively impact cellular immunotherapy, with a focus on NK cell.

• Keywords
• NK cell, T cell, cytotoxicity, immunometabolism, immunosuppression,, immunotherapy, lactate,
• MeSH
• Killer Cells, Natural MeSH
• Immunotherapy MeSH
• Lactic Acid MeSH
• Humans MeSH
• Tumor Microenvironment * MeSH
• Neoplasms * therapy   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH
• Names of Substances
• Lactic Acid MeSH

Accumulating preclinical evidence indicates that Toll-like receptor (TLR) agonists efficiently boost tumor-targeting immune responses (re)initiated by most, if not all, paradigms of anticancer immunotherapy. Moreover, TLR agonists have been successfully employed to ameliorate the efficacy of various chemotherapeutics and targeted anticancer agents, at least in rodent tumor models. So far, only three TLR agonists have been approved by regulatory agencies for use in cancer patients. Moreover, over the past decade, the interest of scientists and clinicians in these immunostimulatory agents has been fluctuating. Here, we summarize recent advances in the preclinical and clinical development of TLR agonists for cancer therapy.

• Keywords
• Ampligen™, G100, Hiltonol™, bacillus Calmette-Guérin, imiquimod, motolimod,
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH

During the past decade, great efforts have been dedicated to the development of clinically relevant interventions that would trigger potent (and hence potentially curative) anticancer immune responses. Indeed, developing neoplasms normally establish local and systemic immunosuppressive networks that inhibit tumor-targeting immune effector cells, be them natural or elicited by (immuno)therapy. One possible approach to boost anticancer immunity consists in the (generally systemic) administration of recombinant immunostimulatory cytokines. In a limited number of oncological indications, immunostimulatory cytokines mediate clinical activity as standalone immunotherapeutic interventions. Most often, however, immunostimulatory cytokines are employed as immunological adjuvants, i.e., to unleash the immunogenic potential of other immunotherapeutic agents, like tumor-targeting vaccines and checkpoint blockers. Here, we discuss recent preclinical and clinical advances in the use of some cytokines as immunostimulatory agents in oncological indications.

• Keywords
• Anticancer vaccines, GM-CSF, IL-2, Type I interferon, checkpoint blockers, oncolytic virotherapy,
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH

One type of anticancer vaccine relies on the administration of DNA constructs encoding one or multiple tumor-associated antigens (TAAs). The ultimate objective of these preparations, which can be naked or vectored by non-pathogenic viruses, bacteria or yeast cells, is to drive the synthesis of TAAs in the context of an immunostimulatory milieu, resulting in the (re-)elicitation of a tumor-targeting immune response. In spite of encouraging preclinical results, the clinical efficacy of DNA-based vaccines employed as standalone immunotherapeutic interventions in cancer patients appears to be limited. Thus, efforts are currently being devoted to the development of combinatorial regimens that allow DNA-based anticancer vaccines to elicit clinically relevant immune responses. Here, we discuss recent advances in the preclinical and clinical development of this therapeutic paradigm.

• Keywords
• AFP, α-fetoprotein, APC, antigen-presenting cell, CDR, complementarity-determining region, CEA, carcinoembryonic antigen, CIN, cervical intraepithelial neoplasia, CTLA4, cytotoxic T lymphocyte protein 4, DAMP, damage-associated molecular pattern, DC, dendritic cell, FDA, Food and Drug Administration, GM-CSF, granulocyte macrophage colony-stimulating factor, GX-188E, HCC, hepatocellular carcinoma, HNSCC, head and neck squamous cell carcinoma, HPV, human papillomavirus, IL, interleukin, OS, overall survival, OVA, ovalbumin, PAP, prostate acid phosphatase, SCGB2A2, secretoglobin, family 2A, member 2, SOX2, SRY (sex determining region Y)-box 2, T, brachyury homolog, TAA, tumor-associated antigen, TLR, Toll-like receptor, TRA, tumor rejection antigen, Treg, regulatory T cell, VGX-3100, WT1, Wilms tumor 1, adjuvants, dendritic cell, electroporation, mucosal immunity,
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Immunomodulatory monoclonal antibodies (mAbs) differ from their tumor-targeting counterparts because they exert therapeutic effects by directly interacting with soluble or (most often) cellular components of the immune system. Besides holding promise for the treatment of autoimmune and inflammatory disorders, immunomodulatory mAbs have recently been shown to constitute a potent therapeutic weapon against neoplastic conditions. One class of immunomodulatory mAbs operates by inhibiting safeguard systems that are frequently harnessed by cancer cells to establish immunological tolerance, the so-called "immune checkpoints." No less than 3 checkpoint-blocking mAbs have been approved worldwide for use in oncological indications, 2 of which during the past 12 months. These molecules not only mediate single-agent clinical activity in patients affected by specific neoplasms, but also significantly boost the efficacy of several anticancer chemo-, radio- or immunotherapies. Here, we summarize recent advances in the development of checkpoint-blocking mAbs, as well as of immunomodulatory mAbs with distinct mechanisms of action.

• Keywords
• CRC, colorectal carcinoma, CTLA4, cytotoxic T lymphocyte-associated protein 4, FDA, Food and Drug Administration, IL, interleukin, KIR, killer cell immunoglobulin-like receptor, MEDI4736, MPDL3280A, NK, natural killer, NSCLC, non-small cell lung carcinoma, PD-1, programmed cell death 1, RCC, renal cell carcinoma, TGFβ1, transforming growth factor β1, TLR, Toll-like receptor, TNFRSF, tumor necrosis factor receptor superfamily, Treg, regulatory T cell, ipilimumab, mAb, monoclonal antibody, nivolumab, pembrolizumab, urelumab,
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH