Targeting PD-1 T cells with small-format immunocytokines enhances IL-12 antitumor activity.

Immunostimulatory cytokines and immune checkpoint inhibitors hold promise as cancer therapeutics; however, their use is often limited by reduced efficacy and significant toxicity. In this study, we developed small-format immunocytokines (ICKs) based on interleukin-12 (IL-12) and blocking nanobodies (Nbs) targeting mouse and human programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1). Both PD-1- and PD-L1-targeted ICKs demonstrated similar in vitro performance, significantly increasing IL-12 tethering to immune cells and enhancing T cell cytotoxic activity compared with IL-12 alone.

Tethered IL15-IL15Rα augments antitumor activity of CD19 CAR-T cells but displays long-term toxicity in an immunocompetent lymphoma mouse model.

Background: Adoptive cell therapy using genetically modified T cells to express chimeric antigen receptors (CAR-T) has shown encouraging results, particularly in certain blood cancers. Nevertheless, over 40% of B cell malignancy patients experience a relapse after CAR-T therapy, likely due to inadequate persistence of the modified T cells in the body. IL15, known for its pro-survival and proliferative properties, has been suggested for incorporation into the fourth generation of CAR-T cells to enhance their persistence.

Local delivery of optimized nanobodies targeting the PD-1/PD-L1 axis with a self-amplifying RNA viral vector induces potent antitumor responses.

Despite the success of immune checkpoint blockade for cancer therapy, many patients do not respond adequately. We aimed to improve this therapy by optimizing both the antibodies and their delivery route, using small monodomain antibodies (nanobodies) delivered locally with a self-amplifying RNA (saRNA) vector based on Semliki Forest virus (SFV). We generated nanobodies against PD-1 and PD-L1 able to inhibit both human and mouse interactions.

Targeting the extra domain A of fibronectin for cancer therapy with CAR-T cells.

Background: One of the main difficulties of adoptive cell therapies with chimeric antigen receptor (CAR)-T cells in solid tumors is the identification of specific target antigens. The tumor microenvironment can present suitable antigens for CAR design, even though they are not expressed by the tumor cells. We have generated a CAR specific for the splice variant extra domain A (EDA) of fibronectin, which is highly expressed in the tumor stroma of many types of tumors but not in healthy tissues.

Overcoming T cell dysfunction in acidic pH to enhance adoptive T cell transfer immunotherapy.

The high metabolic activity and insufficient perfusion of tumors leads to the acidification of the tumor microenvironment (TME) that may inhibit the antitumor T cell activity. We found that pharmacological inhibition of the acid loader chloride/bicarbonate anion exchanger 2 (Ae2), with 4,4'-diisothiocyanatostilbene-2,2'-disulfonicacid (DIDS) enhancedCD4 andCD8 T cell function upon TCR activation , especially under low pH conditions. , DIDS administration delayed B16OVA tumor growth in immunocompetent mice as monotherapy or when combined with adoptive T cell transfer of OVA-specificT cells.

TCR-induced FOXP3 expression by CD8 T cells impairs their anti-tumor activity.

Adoptive cell transfer therapy using CD8 T lymphocytes showed promising results eradicating metastatic malignancies. However, several regulatory mechanisms limit its efficacy. We studied the role of the expression of the transcription factor FOXP3 on CD8 T cell function and anti-tumor immunity.

Searching for Peptide Inhibitors of T Regulatory Cell Activity by Targeting Specific Domains of FOXP3 Transcription Factor.

(1) Background: The ability of cancer cells to evade the immune system is due in part to their capacity to induce and recruit T regulatory cells (Tregs) to the tumor microenvironment. Strategies proposed to improve antitumor immunity by depleting Tregs generally lack specificity and raise the possibility of autoimmunity. Therefore, we propose to control Tregs by their functional inactivation rather than depletion.

Intratumoral STING Agonist Injection Combined with Irreversible Electroporation Delays Tumor Growth in a Model of Hepatocarcinoma.

Background/aim: Irreversible electroporation (IRE) showed promising results for small-size tumors and very early cancers. However, further development is needed to evolve this procedure into a more efficient ablation technique for long-term control of tumor growth. In this work, we show that it is possible to increase the antitumor efficiency of IRE by simmultaneously injecting c-di-GMP, a STING agonist, intratumorally.

Genetic Modification of CD8 T Cells to Express EGFR: Potential Application for Adoptive T Cell Therapies.

Adoptive immunotherapy with -expanded tumor-infiltrating lymphocytes (TILs) has achieved objective clinical responses in a significant number of patients with cancer. The failure of many patients to develop long-term tumor control may be, in part, due to exhaustion of transferred T cells in the presence of a hostile tumor microenvironment. In several tumor types, growth and survival of carcinoma cells appear to be sustained by a network of receptors/ligands of the ErbB family.

Short-Term Local Expression of a PD-L1 Blocking Antibody from a Self-Replicating RNA Vector Induces Potent Antitumor Responses.

Immune checkpoint blockade has shown anti-cancer efficacy, but requires systemic administration of monoclonal antibodies (mAbs), often leading to adverse effects. To avoid toxicity, mAbs could be expressed locally in tumors. We developed adeno-associated virus (AAV) and Semliki Forest virus (SFV) vectors expressing anti-programmed death ligand 1 (aPDL1) mAb.

Therapeutic Effect of Irreversible Electroporation in Combination with Poly-ICLC Adjuvant in Preclinical Models of Hepatocellular Carcinoma.

Purpose: To evaluate the therapeutic efficacy of irreversible electroporation (IRE) combined with the intratumoral injection of the immunogenic adjuvant poly-ICLC (polyinosinic-polycytidylic acid and poly-L-lysine, a dsRNA analog mimicking viral RNA) inmediately before IRE.

Materials And Methods: Mice and rabbits bearing hepatocellular carcinoma tumors (Hepa.129 and VX2 tumor models, respectively) were treated with IRE (2 pulses of 2500V), with poly-ICLC, or with IRE + poly-ICLC combination therapy.

Immunomodulatory Properties of Carvone Inhalation and Its Effects on Contextual Fear Memory in Mice.

A complex network of interactions exists between the immune, the olfactory, and the central nervous system (CNS). Inhalation of different fragrances can affect immunological reactions in response to an antigen but also may have effects on the CNS and cognitive activity. We performed an exploratory study of the immunomodulatory ability of a series of compounds representing each of the 10 odor categories or clusters described previously.

Blockage of FOXP3 transcription factor dimerization and FOXP3/AML1 interaction inhibits T regulatory cell activity: sequence optimization of a peptide inhibitor.

Although T regulatory cells (Treg) are essential for the prevention of autoimmune diseases, their immunoregulatory function restrains the induction of immune responses against cancer. Thus, development of inhibitors of FOXP3, a key transcription factor for the immunosuppressive activity of Treg, might give new therapeutic opportunities. In a previous work we identified a peptide (named P60) able to enter into the cells, bind to FOXP3, and impair Treg activity and .

Inhibition of FOXP3/NFAT Interaction Enhances T Cell Function after TCR Stimulation.

Regulatory T cell (Treg) activity is modulated by a cooperative complex between the transcription factor NFAT and FOXP3, a lineage specification factor for Tregs. FOXP3/NFAT interaction is required to repress expression of IL-2, upregulate expression of the Treg markers CTLA4 and CD25, and confer suppressor function to Tregs. However, FOXP3 is expressed transiently in conventional CD4(+) T cells upon TCR stimulation and may lead to T cell hyporesponsiveness.

A fusion protein between streptavidin and the endogenous TLR4 ligand EDA targets biotinylated antigens to dendritic cells and induces T cell responses in vivo.

The development of tools for efficient targeting of antigens to antigen presenting cells is of great importance for vaccine development. We have previously shown that fusion proteins containing antigens fused to the extra domain A from fibronectin (EDA), an endogenous TLR4 ligand, which targets antigens to TLR4-expressing dendritic cells (DC), are highly immunogenic. To facilitate the procedure of joining EDA to any antigen of choice, we have prepared the fusion protein EDAvidin by linking EDA to the N terminus of streptavidin, allowing its conjugation with biotinylated antigens.

Immunization against hepatitis C virus with a fusion protein containing the extra domain A from fibronectin and the hepatitis C virus NS3 protein.

Background/aims: Vaccination strategies able to induce strong T-cell responses might contribute to eradicate hepatitis C virus (HCV) infection. We previously demonstrated that fusion of an antigen to the extra domain A from fibronectin (EDA) targets the antigen to TLR4-expressing dendritic cells (DC) and improves its immunogenicity. Here, we studied if fusion of EDA with the non-structural HCV protein NS3 might constitute an effective immunogen against HCV.

The extra domain A from fibronectin targets antigens to TLR4-expressing cells and induces cytotoxic T cell responses in vivo.

Vaccination strategies based on the in vivo targeting of Ags to dendritic cells (DCs) are needed to improve the induction of specific T cell immunity against tumors and infectious agents. In this study, we have used a recombinant protein encompassing the extra domain A from fibronectin (EDA), an endogenous ligand for TLR4, to deliver Ags to TLR4-expressing DC. The purified EDA protein was shown to bind to TLR4-expressing HEK293 cells and to activate the TLR4 signaling pathway.

Enhancement of CD4 and CD8 immunity by anti-CD137 (4-1BB) monoclonal antibodies during hepatitis C vaccination with recombinant adenovirus.

The induction of protective or therapeutic cellular immunity against hepatitis C virus (HCV) is a difficult goal. In a previous work we showed that immunization with a recombinant adenovirus encoding HCV-NS3 (RAdNS3) could partially protect mice from challenge with a vaccinia virus encoding HCV antigens. We sought to investigate whether systemic administration of an immunostimulatory monoclonal antibody directed against the lymphocyte surface molecule CD137 could enhance the immunity elicited by RAdNS3.

A recombinant adenovirus encoding hepatitis C virus core and E1 proteins protects mice against cytokine-induced liver damage.

Hepatitis C virus (HCV) infection has a strong tendency to evolve to chronicity despite up-regulation of proapoptotic cytokines in the inflamed liver. The mechanisms responsible for persistent viral replication in this inflammatory environment are obscure. It is conceivable that viral replication would be facilitated if the infected hepatocytes are rendered resistant to cytokine-induced cytotoxicity.

Vaccination with an adenoviral vector encoding hepatitis C virus (HCV) NS3 protein protects against infection with HCV-recombinant vaccinia virus.

Cellular immune response plays an important role in the clearance of hepatitis C virus (HCV). Thus, development of efficient ways to induce anti-viral cellular immune responses is an important step toward prevention and/or treatment of HCV infection. With this aim, we have constructed a replication-deficient recombinant adenovirus expressing HCV NS3 protein (RAdNS3).