The potential role of short chain fatty acids improving ex vivo T and CAR-T cell fitness and expansion for cancer immunotherapies

Adoptive cell therapies, like tumor-infiltrating lymphocytes or chimeric antigen receptor T cells, have become an important immunotherapeutic approach against cancer. One of the main struggles of T cell immunotherapies is how to obtain the most effective T cell phenotype, persistence, and differentiation potential to infuse into patients. Adjusting the T cell ex vivo cell culture conditions is a key factor to increase and improve the efficacy of cellular immunotherapies. In this review, we have summarized the ex vivo impact of short chain fatty acids, a group of gut microbiota derived metabolites, on T cell culture and expansion for immunotherapies. There is a complex gut microbiota-immune system interaction that can affect antitumor immunotherapy efficacy. Indeed, gut microbiota derived metabolites can modulate different biological functions in the immune system local and systemically

A Tumor Mitochondria Vaccine Protects against Experimental Renal Cell Carcinoma

Mitochondria provide energy for cells via oxidative phosphorylation. Reactive oxygen species, a byproduct of this mitochondrial respiration, can damage mitochondrial DNA (mtDNA), and somatic mtDNA mutations have been found in all colorectal, ovarian, breast, urinary bladder, kidney, lung, and pancreatic tumors studied. The resulting altered mitochondrial proteins or tumor-associated mitochondrial Ags (TAMAs) are potentially immunogenic, suggesting that they may be targetable Ags for cancer immunotherapy. In this article, we show that the RENCA tumor cell line harbors TAMAs that can drive an antitumor immune response. We generated a cellular tumor vaccine by pulsing dendritic cells with enriched mitochondrial proteins from RENCA cells. Our dendritic cell-based RENCA mitochondrial lysate vaccine elicited a cytotoxic T cell response in vivo and conferred durable protection against challenge with RENCA cells when used in a prophylactic or therapeutic setting. By sequencing mtDNA from RENCA cells, we identified two mutated molecules: COX1 and ND5. Peptide vaccines generated from mitochondrial-encoded COX1 but not from ND5 had therapeutic properties similar to RENCA mitochondrial protein preparation. Thus, TAMAs can elicit effective antitumor immune responses, potentially providing a new immunotherapeutic strategy to treat cancer

Estudi de les vies del TNF/TNFR2 i del CD200/CD200R en el rebuig xenogènic

[cat] Les aplicacions xenogèniques podrien anar des del xenotrasplantament d'òrgans sòlids, a l'empelt de teixits o cèl·lules. El principal obstacle per a la seva aplicació és la forta resposta immunitària generada pel xenoempelt, mediada tant per mecanismes cel·lulars com humorals. Diverses vies de senyalització i molècules estan relacionades amb aquest rebuig. En aquest treball s'estudien la via del TNF/TNFR i del CD200/CD200R. El TNFα s'uneix específicament a dos receptors, el TNFR1 i el TNFR2. Diferents estudis han demostrat la seva implicació en el rebuig agut de l'empelt xenogènic. En aquest treball s'ha identificat i caracteritzat diverses variants del TNFR2 porcí generades a partir de dos tipus diferents de splicings. El primer, provoca la deleció de l'exó 4, per homologia amb la seqüència humana. El segon engloba el que correspondria per homologia als exons 7 al 10 humans i provoca que la predicció de la proteïna resultant sigui soluble. En els experiments de PCR en temps real es va detectar els dos tipus de splicing a nivell de RNA en tots els teixits analitzats. Els nivells globals més elevats els trobem en cèl·lules del sistema immunitari com els PBMC o els monòcits aïllats i en òrgans com la melsa i el pulmó. La determinació de les diferents variants per separat mostren com els dos tipus de splicings són més abundants en monòcits aïllats o PBMC. Els estudis de localització subcel·lular ens van permetre identificar dos patrons d'expressió diferents. Per una banda el pTNFR2 té un marcat patró membranal. En canvi, la isoforma que conté el splicing a l'exó 4 és totalment intracel·lular, amb una alta colocalització amb el reticle endoplasmàtic. Tot i així els estudis realitzats amb la tècnica de FRET, han posat de relleu la interacció entre pTNFR2 i pTNFR2ΔE4 en l'espai intracel·lular. Els receptors de TNF formen homotrímers per ser funcionals, en aquest treball també hem demostrat que les proteïnes solubles són capaces de combinar-se entre elles de forma específica i que aquesta combinació és funcional. El CD200 regula l'activitat de les cèl·lules mieloides a través de la interacció amb el seu receptor. Diferents estudis han descrit el paper immunoregulador de la interacció CD200-CD200R en el control del rebuig de l'al·lotrasplantament i del xenotrasplantament concordant. La segona part d'aquesta tesi està dedicada a la identificació i caracterització del CD200 i CD200R porcins. Els resultats obtinguts identifiquen, per primera vegada, el CD200 porcí i tres variants del seu receptor. Una anàlisi bioinformàtica va permetre caracteritzar la molècula i comprovar que té un patró molt similar al descrit pel CD200 d'altres espècies, dos dominis d'immunoglobulines, una transmembrana i una regió citosòlica curta sense motius senyalitzadors coneguts. La primera variant de receptor pCD200R1, té una homologia elevada amb la variant a del receptor humà. La primera i segona variant soluble, el pCD200R2 i pCD200R3, contenen un canvi en el marc de lectura i que fa aparèixer un codó de stop primerenc, just abans de la zona de transmembrana. El receptor porcí té els tres llocs d'unió a CD200 més crítics conservats. Gràcies a la tecnologia de la ressonància de plasmó de superfície, vam determinar que les constant d'afinitats entre CD200-CD200R estan al voltant de 10-7 i 10-8 M tan en sistemes al·logènics com xenogènics. Amb la finalitat d'identificar les proteïnes porcines del CD200 i del seu receptor, es van generar antipèptids i es van produir anticossos policlonals en conills útils tan en anàlisi de Western Blot com per citometria de flux. Els experiments de PCR en temps real van determinar i quantificar l'expressió del CD200 porcí. Els resultat van confirmar que està àmpliament distribuït per diferents teixits i tipus cel·lulars[eng] Clinical xenotransplantation is precluded by the strong immune rejection of the xenograft in which several molecules and pathways are involved. In this doctoral thesis, we studied the TNF/TNFR2 and CD200/CD200R pathways in the pig-to-human xenogeneic setting. First, we cloned the cDNA of porcine TNF-Receptor 2 and obtained four isoforms, two membrane-bound (pTNFR2 and pTNFR2ΔE4) and two soluble (pTNFR2ΔE7-10 and pTNFR2ΔE4ΔE7-10), generated by 2 different alternative splicings. The global expression and the relative proportion of each alternative splicing were determined by quantitative RT-PCR. All cells/tissues tested expressed the receptor at various levels and had a low-to-moderate percentage of each alternative splicing. We never found pTNFR2ΔE4 on the cell surface, but demonstrated by FRET experiments that it was capable of associating to the full pTNFR2 intracellularly. Next, we produced fusion proteins with the two different extracellular domains and determined their affinity to pig and human TNFα by plasmon resonance. The pTNFR2-GST bound both pTNFα and hTNFα with high and comparable affinity to the human receptor. On the contrary, pTNFR2ΔE4-GST showed no binding to hTNFα and very little to pTNFα. We further confirmed with pull down experiments that pTNFR2 and pTNFR2ΔE4 bound together after producing them simultaneously as soluble fusion proteins with different tags in mammalian cells. Moreover, pTNFR2ΔE4-GST failed to inhibit the hTNFα effect on endothelial cells in a competition assay, but was able to diminish the TNF blockade mediated by pTNFR2-GST. Thus, we reveal a new way the TNF/TNFR pathway is regulated. In other hand, we have cloned porcine CD200 and three variants of its receptor. As in other species, the porcine CD200 mRNA expression was widely distributed in the multiple tissues tested. We produced rabbit anti-peptide and polyclonal antibodies specific for pig CD200 and both detected it successfully by flow cytometry and western blotting. We also examined if ligand and receptor binding was conserved among species by plasmon resonance. Porcine CD200 interacted with human CD200R with an affinity comparable to that of human CD200. Finally, we expressed recombinantly human and porcine CD200 on the surface of porcine cells in order to protect them against xenograft rejection

Gut Microbiota Influence in Hematological Malignancies: From Genesis to Cure

Hematological malignancies, including multiple myeloma, lymphoma, and leukemia, are a heterogeneous group of neoplasms that affect the blood, bone marrow, and lymph nodes. They originate from uncontrolled growth of hematopoietic and lymphoid cells from different stages in their maturation/differentiation and account for 6.5% of all cancers around the world. During the last decade, it has been proven that the gut microbiota, more specifically the gastrointestinal commensal bacteria, is implicated in the genesis and progression of many diseases. The immune-modulating effects of the human microbiota extend well beyond the gut, mostly through the small molecules they produce. This review aims to summarize the current knowledge of the role of the microbiota in modulating the immune system, its role in hematological malignancies, and its influence on different therapies for these diseases, including autologous and allogeneic stem cell transplantation, chemotherapy, and chimeric antigen receptor T cells

Gut Microbiota Influence in Hematological Malignancies: From Genesis to Cure

Hematological malignancies, including multiple myeloma, lymphoma, and leukemia, are a heterogeneous group of neoplasms that affect the blood, bone marrow, and lymph nodes. They originate from uncontrolled growth of hematopoietic and lymphoid cells from different stages in their maturation/differentiation and account for 6.5% of all cancers around the world. During the last decade, it has been proven that the gut microbiota, more specifically the gastrointestinal commensal bacteria, is implicated in the genesis and progression of many diseases. The immune-modulating effects of the human microbiota extend well beyond the gut, mostly through the small molecules they produce. This review aims to summarize the current knowledge of the role of the microbiota in modulating the immune system, its role in hematological malignancies, and its influence on different therapies for these diseases, including autologous and allogeneic stem cell transplantation, chemotherapy, and chimeric antigen receptor T cells

Ovarian granulosa cell tumor characterization identifies FOXL2 as an immunotherapeutic target

Granulosa cell tumors (GCT) are rare ovarian malignancies. Due to the lack of effective treatment in late relapse, there is a clear unmet need for novel therapies. Forkhead Box L2 (FOXL2) is a protein mainly expressed in granulosa cells (GC) and therefore is a rational therapeutic target. Since we identified tumor infiltrating lymphocytes (TILs) as the main immune population within GCT, TILs from 11 GCT patients were expanded, and their phenotypes were interrogated to determine that T cells acquired late antigen-experienced phenotypes and lower levels of PD1 expression. Importantly, TILs maintained their functionality after ex vivo expansion as they vigorously reacted against autologous tumors (100% of patients) and against FOXL2 peptides (57.1% of patients). To validate the relevance of FOXL2 as a target for immune therapy, we developed a plasmid DNA vaccine (FoxL2–tetanus toxin; FoxL2-TT) by fusing Foxl2 cDNA with the immune-enhancing domain of TT. Mice immunization with FoxL2-TT controlled growth of FOXL2-expressing ovarian (BR5) and breast (4T1) cancers in a T cell–mediated manner. Combination of anti–PD-L1 with FoxL2-TT vaccination further reduced tumor progression and improved mouse survival without affecting the female reproductive system and pregnancy. Together, our results suggest that FOXL2 immune targeting can produce substantial long-term clinical benefits. Our study can serve as a foundation for trials testing immunotherapeutic approaches in patients with ovarian GCT

CAR-T after Stem Cell Transplantation in B-Cell Lymphoproliferative Disorders: Are They Really Autologous or Allogenic Cell Therapies?

Allogenic hematopoietic stem cell transplantation (allo-HSCT) is one of the standard treatments for B-cell lymphoproliferative disorders; however, deep relapses are common after an allo-HSCT, and it is associated with poor prognosis. A successful approach to overcome these relapses is to exploit the body’s own immune system with chimeric antigen receptor (CAR) T-cells. These two approaches are potentially combinatorial for treating R/R B-cell lymphoproliferative disorders. Several clinical trials have described different scenarios in which allo-HSCT and CAR-T are successively combined. Further, for all transplanted patients, assessment of chimerism is important to evaluate the engraftment success. Nonetheless, for those patients who previously received an allo-HSCT there is no monitorization of chimerism before manufacturing CAR T-cells. In this review, we focus on allo-HSCT and CAR-T treatments and the different sources of T-cells for manufacturing CAR T-cells

Combination of vasculature targeting, hypofractionated radiotherapy, and immune checkpoint inhibitor elicits potent antitumor immune response and blocks tumor progression

Background Tumor endothelial marker 1 (TEM1) is a protein expressed in the tumor-associated endothelium and/or stroma of various types of cancer. We previously demonstrated that immunization with a plasmid-DNA vaccine targeting TEM1 reduced tumor progression in three murine cancer models. Radiation therapy (RT) is an established cancer modality used in more than 50% of patients with solid tumors. RT can induce tumor-associated vasculature injury, triggering immunogenic cell death and inhibition of the irradiated tumor and distant non-irradiated tumor growth (abscopal effect). Combination treatment of RT with TEM1 immunotherapy may complement and augment established immune checkpoint blockade.Methods Mice bearing bilateral subcutaneous CT26 colorectal or TC1 lung tumors were treated with a novel heterologous TEM1-based vaccine, in combination with RT, and anti-programmed death-ligand 1 (PD-L1) antibody or combinations of these therapies, tumor growth of irradiated and abscopal tumors was subsequently assessed. Analysis of tumor blood perfusion was evaluated by CD31 staining and Doppler ultrasound imaging. Immunophenotyping of peripheral and tumor-infiltrating immune cells as well as functional analysis was analyzed by flow cytometry, ELISpot assay and adoptive cell transfer (ACT) experiments.Results We demonstrate that addition of RT to heterologous TEM1 vaccination reduces progression of CT26 and TC1 irradiated and abscopal distant tumors as compared with either single treatment. Mechanistically, RT increased major histocompatibility complex class I molecule (MHCI) expression on endothelial cells and improved immune recognition of the endothelium by anti-TEM1 T cells with subsequent severe vascular damage as measured by reduced microvascular density and tumor blood perfusion. Heterologous TEM1 vaccine and RT combination therapy boosted tumor-associated antigen (TAA) cross-priming (ie, anti-gp70) and augmented programmed cell death protein 1 (PD-1)/PD-L1 signaling within CT26 tumor. Blocking the PD-1/PD-L1 axis in combination with dual therapy further increased the antitumor effect and gp70-specific immune responses. ACT experiments show that anti-gp70 T cells are required for the antitumor effects of the combination therapy.Conclusion Our findings describe novel cooperative mechanisms between heterologous TEM1 vaccination and RT, highlighting the pivotal role that TAA cross-priming plays for an effective antitumor strategy. Furthermore, we provide rationale for using heterologous TEM1 vaccination and RT as an add-on to immune checkpoint blockade as triple combination therapy into early-phase clinical trials