scholarly journals IMMU-27. IMMUNE CHECKPOINT BLOCKADE OF EX VIVO EXPANDED T CELLS FOR USE IN ADOPTIVE CELLULAR THERAPY (ACT) FOR GLIOBLASTOMA

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi124-vi125
Author(s):  
Elizabeth Ogando-Rivas ◽  
Changlin Yang ◽  
Paul Castillo ◽  
Anjelika Dechkovskaia ◽  
Duane Mitchell
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Immune Checkpoint ◽  
Cellular Therapy ◽  
Ex Vivo ◽  
Immune Checkpoint Blockade ◽  
Checkpoint Blockade ◽  
Study Objective

Abstract BACKGROUND Despite aggressive treatments, GBM continues to have unacceptably high mortality rates. Immune-checkpoint blockade and ACT have shown excellent results in other solid tumors, especially in melanoma. Unfortunately, these results have not been extrapolated to GBM. We have developed a novel platform for ACT using tumor mRNA-pulsed dendritic cells(DCs) to in-vitro expand polyclonal populations of tumor-reactive T-cells. This platform has shown promising effects in preclinical brain tumor models (Flores et al OncoImmunology 2015, Wildes et al CCR 2018, Flores et al NatureComm 2018) and being evaluated in clinical trials at UF Health (NCT02465268,NCT03334305). STUDY OBJECTIVE Evaluate whether immune-checkpoint blockade during ex-vivo expansion of antigen-specific T-cells impact their use in ACT. METHODS CMVpp65 was used as model antigen for in-vitro activation of T-cells. Mature pp65 mRNA-pulsed DCs from CMV+ healthy donors were co-cultured with T-cells in IL2-containing medium for 15days. We tested four checkpoint inhibitor groups: PD1(n= 6), PDL1(n= 4), TIM3(n= 7) and PD1+TIM3(n= 6) that were compared with non-blockade group, respectively. Checkpoint blockade was performed every 3days. T-cell proliferation, immune-phenotyping, and IFN-g release were analyzed. RESULTS Cell proliferation was lower in all the blockade groups but significantly lower in the TIM3 (p= 0.03) and TIM3+PD1 (p= 0.01) blockade groups. TIM3 expression was significantly lower in the TIM3 (p= 0.006) and PD1+TIM3 blockade groups (p= 0.0001). There was a trend of reduced pp65 tetramer positive in the TIM3 and PD1+TIM3 blockade groups (PD1+TIM3 subgroup at 3mcg/mL, p= 0.02) and lower INFg release in the TIM3 and PD1+TIM3 blockade groups. CONCLUSION The exact role of checkpoints during expansion of T-cells for ACT is not well understood. In our study checkpoint blockade with PD-1 or TIM-3 alone or in combination did not enhance T-cell expansion or function, in fact, appeared to have an inhibitory effect on measured parameters. Our results suggest that TIM-3 may have an activating role in our system.

scholarly journals Combined PD-L1 and TIM-3 blockade improves the expansion of fit human CD8+ antigen-specific T cells for adoptive immunotherapy

2021 ◽  
Author(s):  
Shirin Lak ◽  
Valérie Janelle ◽  
Anissa Djedid ◽  
Gabrielle Boudreau ◽  
Ann Brasey ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Checkpoint ◽  
Cell Expansion ◽  
Ex Vivo ◽  
Immune Checkpoint Blockade ◽  
Checkpoint Blockade ◽  
Immune Checkpoints ◽  
T Cell Expansion ◽  
And Function

AbstractBackgroundThe stimulation and expansion of antigen-specific T cells ex vivo enables the targeting of a multitude of cancer antigens. However, clinical scale T-cell expansion from rare precursors requires repeated stimulations ex vivo leading to T-cell terminal effector differentiation and exhaustion that adversely impact therapeutic potential. We leveraged immune checkpoint blockade relevant to antigen-specific CD8+ human T cells to improve the expansion and function of T cells targeting clinically relevant antigens.MethodsA clinically-compliant protocol relying on peptide-pulsed monocyte-derived dendritic cells and cytokines was used to expand antigen-specific CD8+ targeting the oncogenic Epstein-Barr virus (EBV) and the tumor associated antigen (TAA) Wilms Tumor 1 (WT1) protein. The effects of antibody-mediated blockade of immune checkpoints applied to the cultures (T-cell expansion, phenotypes and function) were assessed at various time points. Genomic studies including single cell RNA (scRNA) sequencing and T-cell receptor sequencing were performed on EBV-specific T cells to inform about the impact of immune checkpoint blockade on the clonal distribution and gene expression of the expanded T cells.ResultsSeveral immune checkpoints were expressed early by ex vivo expanded antigen-specific CD8+ T cells, including PD-1 and TIM-3 with co-expression matching evidence of T-cell dysfunction as the cultures progressed. The introduction of anti-PD-L1 (expressed by the dendritic cells) and anti-TIM-3 antibodies in combination (but not individually) to the culture led to markedly improved antigen-specific T-cell expansion based on cell counts, fluorescent multimer staining and functional tests. This was not associated with evidence of T-cell dysfunction when compared to T cells expanded without immune checkpoint blockade. Genomics studies largely confirmed these results, showing that double blockade does not impart specific transcriptional programs or patterns on TCR repertoires. However, our data indicate that combined blockade may nonetheless alter gene expression in a minority of clonotypes and have donor-specific impacts.ConclusionsThe manufacturing of antigen-specific CD8+ T cells can be improved in terms of yield and functionality using blockade of TIM-3 and the PD-L1/PD-1 axis in combination. Overcoming the deleterious effects of multiple antigenic stimulations through PD-L1/TIM-3 blockade is a readily applicable approach for several adoptive-immunotherapy strategies.

A Nanobody Against Cytotoxic T-Lymphocyte Associated Antigen-4 Increases the Anti-Tumor Effects of Specific CD8+ T Cells

2019 ◽  
Vol 15 (11) ◽  
pp. 2229-2239 ◽  
Author(s):  
Zhuoran Tang ◽  
Fengzhen Mo ◽  
Aiqun Liu ◽  
Siliang Duan ◽  
Xiaomei Yang ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Tumor Cells ◽  
Cytotoxic T Lymphocyte ◽  
Ex Vivo ◽  
T Cell Proliferation ◽  
Tumor Cell Apoptosis ◽  
Xenograft Models

Adoptive cell-based immunotherapy typically utilizes cytotoxic T lymphocytes (CTLs), expanding these cells ex vivo. Such expansion is traditionally accomplished through the use of autologous APCs that are capable of interactions with T cells. However, incidental inhibitory program such as CTLA-4 pathway can impair T cell proliferation. We therefore designed a nanobody which is specific for CTLA-4 (CTLA-4 Nb 16), and we then used this molecule to assess its ability to disrupt CTLA-4 signaling and thereby overcome negative costimulation of T cells. With CTLA-4 Nb16 stimulation, dendritic cell/hepatocellular carcinoma fusion cells (DC/HepG2-FCs) enhanced autologous CD8+ T cell proliferation and production of IFN-γ in vitro, thereby leading to enhanced killing of tumor cells. Using this approach in the context of adoptive CD8+ immunotherapy led to a marked suppression of tumor growth in murine NOD/SCID hepatocarcinoma or breast cancer xenograft models. We also observed significantly increased tumor cell apoptosis, and corresponding increases in murine survival. These findings thus demonstrate that in response to nanobody stimulation, DC/tumor cells-FC-induced specific CTLs exhibit superior anti-tumor efficacy, making this a potentially valuable means of achieving better adoptive immunotherapy outcomes in cancer patients.

SOX2 as a target for immunotherapy of pediatric gliomas.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e22012-e22012 ◽  
Author(s):  
Juan Vasquez ◽  
Anita Huttner ◽  
Lin Zhang ◽  
Asher Marks ◽  
Amy Chan ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Cells ◽  
Tumor Immunity ◽  
Immune Checkpoint ◽  
Cell Mass ◽  
Immune Checkpoint Blockade ◽  
Checkpoint Blockade ◽  
Low Grade ◽  
Glial Tumors

e22012 Background: New treatments are needed to improve outcomes for pediatric gliomas. Immune checkpoint inhibitors are effective therapies in tumors with a high mutation burden that express multiple neo-antigens. However, for pediatric tumors that carry few mutations, there is a need to identify new antigenic targets of anti-tumor immunity. SOX2 is an embryonal stem cell antigen implicated in the biology of glioma initiating cells. Expression of SOX2 by pediatric glial tumors, and the capacity of the immune system in these patients to recognize SOX2, has not been studied. Methods: We examined the expression of SOX2 on paraffin-embedded tissue from pediatric glial tumors (n = 30). The presence of T cell immunity to SOX2 was examined in both blood and tumor-infiltrating T cells using antigen-dependent cytokine and T cell proliferation assays (n = 15). The nature of tumor-infiltrating immune cells in glial tumors (n = 4) was analyzed using single cell mass cytometry. Results: SOX2 is expressed by tumor cells but not surrounding normal tissue in all low grade gliomas (n = 15), high grade gliomas (n = 7), ependymomas (n = 3) and in 60% of oligodendrogliomas (n = 5). T cells against SOX2 can be detected in blood and tumor tissue in 33% of patients. CD4 and CD8 tumor infiltrating T-cells display a higher proportion of PD-1 expression compared to circulating T cells (p < 0.05). Glial CD4 and CD8 T cells are enriched for tissue resident memory phenotype (TRM; CD45RO+, CD69+, CCR7-) and the expression of PD-1 is primarily on these TRM cells (p < 0.05). A subset of CD4 and CD8 TRM cells also co-express multiple inhibitory checkpoints including PD-L1 and TIGIT. Glial tumors also contain NK cells with reduced expression of lytic granzyme (p < 0.05). Conclusions: Our data demonstrate in vivo immunogenicity of SOX2, which is specifically overexpressed on pediatric glial tumor cells. Our data also suggest that the TRM subset of tumor-infiltrating T cells may be key targets for immune checkpoint blockade, and harnessing tumor immunity will likely require the combined targeting of multiple inhibitory checkpoints. Future efforts to target SOX2 with dendritic cell vaccines combined with immune checkpoint blockade could provide effective tumor immunity and improve outcomes in pediatric brain tumors.

scholarly journals B cells sustain inflammation and predict response to immune checkpoint blockade in human melanoma

2018 ◽  
Author(s):  
Johannes Griss ◽  
Wolfgang Bauer ◽  
Christine Wagner ◽  
Margarita Maurer-Granofszky ◽  
Martin Simon ◽  
...  
Keyword(s):  
T Cell ◽  
B Cells ◽  
Immune Checkpoint ◽  
Cd8 T Cell ◽  
Immune Checkpoint Blockade ◽  
Human Melanoma ◽  
Checkpoint Blockade ◽  
Inflammatory Factors ◽  
T Effector Cells

Tumor associated inflammation predicts response to immune checkpoint blockade in human melanoma. Established mechanisms that underlie therapy response and resistance center on anti-tumor T cell responses. Here we show that tumor-associated B cells are vital to tumor associated inflammation. Autologous B cells were directly induced by melanoma conditioned medium, expressed pro- and anti-inflammatory factors, and differentiated towards a plasmablast-like phenotype in vitro. We could identify this phenotype as a distinct cluster of B cells in an independent public single-cell RNA-seq dataset from melanoma tumors. There, plasmablast-like tumor-associated B cells showed expression of CD8+T cell-recruiting chemokines such as CCL3, CCL4, CCL5 and CCL28. Depletion of tumor associated B cells in metastatic melanoma patients by anti-CD20 immunotherapy decreased overall inflammation and CD8+T cell numbers in the human melanoma TME. Conversely, the frequency of plasmablast-like B cells in pretherapy melanoma samples predicted response and survival to immune checkpoint blockade in two independent cohorts. Tumor-associated B cells therefore orchestrate and sustain tumor inflammation, recruit CD8+ T effector cells and may represent a predictor for response and survival to immune checkpoint blockade in human melanoma.

scholarly journals HDAC6 Inhibition Alleviates CLL-Induced T-Cell Dysfunction and Enhances Immune Checkpoint Blockade Efficacy in the Eμ-TCL1 Model

2020 ◽  
Vol 11 ◽  
Author(s):  
Kamira Maharaj ◽  
John J. Powers ◽  
Melanie Mediavilla-Varela ◽  
Alex Achille ◽  
Wael Gamal ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Immune Checkpoint ◽  
Immune Checkpoint Blockade ◽  
Tumor Burden ◽  
Checkpoint Blockade ◽  
Cell Phenotype ◽  
Cell Dysfunction ◽  
T Cell Dysfunction

Development of chronic lymphocytic leukemia (CLL) is associated with severe immune dysfunction. T-cell exhaustion, immune checkpoint upregulation, and increase of regulatory T cells contribute to an immunosuppressive tumor microenvironment. As a result, CLL patients are severely susceptible to infectious complications that increase morbidity and mortality. CLL B-cell survival is highly dependent upon interaction with the supportive tumor microenvironment. It has been postulated that the reversal of T-cell dysfunction in CLL may be beneficial to reduce tumor burden. Previous studies have also highlighted roles for histone deacetylase 6 (HDAC6) in regulation of immune cell phenotype and function. Here, we report for the first time that HDAC6 inhibition exerts beneficial immunomodulatory effects on CLL B cells and alleviates CLL-induced immunosuppression of CLL T cells. In the Eμ-TCL1 adoptive transfer murine model, genetic silencing or inhibition of HDAC6 reduced surface expression of programmed death-ligand 1 (PD-L1) on CLL B cells and lowered interleukin-10 (IL-10) levels. This occurred concurrently with a bolstered T-cell phenotype, demonstrated by alteration of coinhibitory molecules and activation status. Analysis of mice with similar tumor burden indicated that the majority of T-cell changes elicited by silencing or inhibition of HDAC6 in vivo are likely secondary to decrease of tumor burden and immunomodulation of CLL B cells. The data reported here suggest that CLL B cell phenotype may be altered by HDAC6-mediated hyperacetylation of the chaperone heat shock protein 90 (HSP90) and subsequent inhibition of the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway. Based on the beneficial immunomodulatory activity of HDAC6 inhibition, we rationalized that HDAC6 inhibitors could enhance immune checkpoint blockade in CLL. Conclusively, combination treatment with ACY738 augmented the antitumor efficacy of anti-PD-1 and anti-PD-L1 monoclonal antibodies in the Eμ-TCL1 adoptive transfer murine model. These combinatorial antitumor effects coincided with an increased cytotoxic CD8+ T-cell phenotype. Taken together, these data highlight a role for HDAC inhibitors in combination with immunotherapy and provides the rationale to investigate HDAC6 inhibition together with immune checkpoint blockade for treatment of CLL patients.

Sirolimus Inhibits Proliferation but Enhances Suppressive Activity of Rhesus Macaque Natural CD4 Regulatory T Cells

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1008-1008
Author(s):  
Karnail Singh ◽  
Natalia Kozyr ◽  
Linda Stempora ◽  
Allan D Kirk ◽  
Christian P Larsen ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Ex Vivo ◽  
Cd8 T Cell ◽  
T Cell Proliferation ◽  
Suppressive Activity ◽  
Suppressive Capacity

Abstract Abstract 1008 Regulatory T cells (Tregs) have been shown to be potent inhibitors of autoimmunity, and to be capable of suppressing alloimmune responses that occur during both allograft rejection and graft-versus host disease. However, they have yet to gain widespread use clinically, due in part to the fact that it remains extremely costly and difficult to produce them in sufficient numbers and with sufficient suppressive capacity to significantly impact the alloimmune response. Here we have used our established non-human primate model to demonstrate that significant Treg expansion (up to 600-fold in 21 days) can be maintained, and suppressive capacity enhanced by exposing Treg cultures to a short burst of sirolimus at the end of the culture period. Using a highly sensitive and specific in vitro CFSE-MLR assay we show that Tregs significantly inhibit allo-proliferation of multiple T cell subpopulations including both CD4+ and CD8+ T cells (3.2 and 2.7-fold inhibition of proliferation, respectively), as well as their CD28+CD95+ and CD28-CD95+ subpopulations (2.2 and 2.1 and 1.9 and 2.7-fold inhibition of CD4+ and CD8+ subpopulation proliferation, respectively). Tregs were able to combine in vitro with the newly FDA-approved CTLA4-Ig analog belatacept to enhance the inhibition of alloproliferation that occurred with either agent alone (4.8-fold inhibition of CD8 T cell proliferation with Tregs + belatacept, compared to 3.0-fold or 1.9-fold inhibition of CD8 T cell proliferation with Tregs or belatacept alone, respectively). Importantly, we have found that the suppressive activity of ex-vivo expanded Tregs could be further enhanced by pulsing with sirolimus. Thus, while long-term culture of Tregs in the presence of sirolimus (1–1000 nM) profoundly inhibited Treg expansion (50–800 fold inhibition of expansion when cultured in the presence of 1–1000 nM sirolimus), a 48 hour pulse of sirolimus (100 nM) on days 20–21 of culture completely preserved Treg yields while doubling their suppressive function against CD8 proliferation when compared to unpulsed Tregs, p<0.01) A mechanistic evaluation of the increase potency observed with sirolimus pulsed Tregs (SPTs) has revealed several key differences that distinguish these cells from the less-potent unpulsed Tregs: SPTs were found to undergo fewer rounds of proliferation in an MLR when compared with unpulsed Tregs (14% proliferation in SPTs versus 37% proliferation in un-pulsed Tregs, p= 0.015), suggesting that the suppressive capability of Tregs may be inversely related to their proliferative capacity. SPTs were also shown to have significantly increased expression of CD25 (p=0.04) and total CTLA4 (p= 0.009) compared to unpulsed Tregs, implicating signaling through both of these molecules in their enhanced function. Our results suggest that the creation of SPTs may provide a novel avenue by which to achieve enhanced Treg-based suppression of alloimmunity, in a manner that is amenable to large-scale ex-vivo expansion and to combinatorial therapy with novel, costimulation-blockade-based immunosuppression strategies. Disclosures: No relevant conflicts of interest to declare.

In Vitro Expansion of CMV-Specific T Cells from CMV Seronegative Donors.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3927-3927
Author(s):  
Stephanie Verfuerth ◽  
Arnold R. Pizzey ◽  
Shoon-Ling C. Chow ◽  
Noha Chowdhry ◽  
Stephen Mackinnon
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Cellular Therapy ◽  
T Cell Proliferation ◽  
Adoptive Cellular Therapy ◽  
Size Classes ◽  
Pulsed Dc ◽  
Ifn Γ

Abstract CMV infection is still a negative prognostic factor in hematopoietic stem cell transplantation, largely due to adverse effects of antiviral chemotherapy. Advances have been made in the development of adoptive cellular therapy for CMV with cell products derived from CMV seropositive donors. However no such cell products from CMV negative donors are currently available, although CMV negative recipients of CMV positive grafts bear the greatest risk of CMV induced morbidity and mortality. Mature DC are capable of inducing in vivo primary T cell responses. We used an in vitro culture system employing MoDC generated with GM-CSF and IL-4, pulsed with CMV lysate and matured with CD40L to induce primary immune responses to CMV. CMV-specific T cell proliferation measured by 3H-Thymidine uptake could be induced in some 6 to 9-day cultures, however, the success rate was very low, and T cells could usually not be kept alive after becoming activated. The addition of IL-15 to cultures after 7 days resulted in some improvement, although some non-CMV specific T cell proliferation in response to control lysate or in the absence of antigen also occurred in some cultures. IL-12 added to cultures from day 0 resulted in a short-term increase in T cell proliferation that was followed by increased cell death and was also not entirely CMV-specific. The real benefit of IL-15, alone or in combination with IL-12, was seen in 2-week cultures: In 6/7 cultures from different CMV seronegative donors counts of viable T cells (by trypan blue exclusion) increased up to 10-fold. Two cultures that were additionally set up with control lysate-pulsed DC to detect proliferation in response to non-CMV components of the antigen, confirmed CMV-specificity. CMV-specificity was also shown by T cell receptor (TCR) complement determining region (CDR) 3 spectratyping. TCR-BV(variable region β)-size class expression patterns across 23 BV families were very similar in pre-culture unstimulated T cells and in T cells stimulated with control lysate-pulsed DC for 2 weeks, showing the typical near-normal distribution of PCR product amongst the different size classes indicative of un-stimulated T cells. T cells co-cultured with CMV lysate-pulsed DC for 2 weeks produced very skewed spectratypes, indicative of oligoclonal T cell expansion in response to the antigen. The effect of IL-15 on T cell spectratypes from CMV antigen-driven cultures was tested using cells from another donor. With or without IL-15, post-culture spectratypes showed oligoclonal T cell expansions in the same BV families and size classes. However, despite their similar shapes, spectratypes from IL-5 containing cultures were skewed to a greater extent, possibly indicating a greater effect of IL-15 on already activated T cells. No CD8+ T cells specific for single immunodominant epitopes could be detected by staining with up to 5 different HLA-CMVpeptide-tetramers in culture output from 4/4 donors. In 1 of 2 cultures analyzed by cytokine secretion assay, a significant sub-population of T cells (1%), in CD4 positive and negative fractions, secreted IFN-γ in response to re-stimulation with CMV antigen. No IFN-γ secreting CMV-specific pre-cursor T cells were detected in fresh PBMC, as expected. Whilst further work is required to make generation of CMV specific T cells from CMV seronegative donors more reproducible and to ensure antigen-specificity, these preliminary data are encouraging for the future generation of CMV-specific T cells from CMV seronegative donors for adoptive cellular therapy.

scholarly journals CXCL13 shapes immunoactive tumor microenvironment and enhances the efficacy of PD-1 checkpoint blockade in high-grade serous ovarian cancer

2021 ◽  
Vol 9 (1) ◽  
pp. e001136
Author(s):  
Moran Yang ◽  
Jiaqi Lu ◽  
Guodong Zhang ◽  
Yiying Wang ◽  
Mengdi He ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
T Cells ◽  
B Cells ◽  
Tumor Microenvironment ◽  
Immune Checkpoint ◽  
Ex Vivo ◽  
Immune Checkpoint Blockade ◽  
Checkpoint Blockade ◽  
High Grade ◽  
Serous Ovarian Cancer

BackgroundMost patients with high-grade serous ovarian cancer (HGSC) lack an effective response to immune checkpoint blockade, highlighting the need for more knowledge about what is required for successful treatment. As follicular cytotoxic CXCR5+CD8+ T cells are maintained by reinvigoration by immune checkpoint blockade in tumors, we attempted to reveal the relationship between CXCR5+CD8+ T cells and the tumor microenvironment to predict immunotherapy responses in HGSC.Methods264 patients with HGSC from two cohorts and 340 HGSC cases from The Cancer Genome Atlas cohort were enrolled. Ex vivo and in vivo studies were conducted with human HGSC tumors and murine tumor models. The spatial correlation between CXC-chemokine ligand 13 (CXCL13), CXCR5, CD8, and CD20 was evaluated by immunohistochemistry and immunofluorescence. Survival was compared between different subsets of patients using Kaplan-Meier analysis. The therapeutic effect of CXCL13 and programmed cell death-1 (PD-1) blockade was validated using human HGSC tumors and murine models.ResultsHigh CXCL13 expression was associated with prolonged survival. Tumors with high CXCL13 expression exhibited increased infiltration of activated and CXCR5-expressing CD8+ T cells. Incubation with CXCL13 facilitated expansion and activation of CXCR5+CD8+ T cells ex vivo. CXCR5+CD8+ T cells appeared in closer proximity to CXCL13 in tumors and chemotaxis towards CXCL13 in vitro. The combination of CXCL13, CXCR5, and CD8+ T cells was an independent predictor for survival. In addition, CXCL13 was associated with clusters of CD20+ B cells. CD20+ B cells predicted better patient survival in the presence of CXCL13. Histological evaluation highlighted colocalization of CXCL13 with tertiary lymphoid structures (TLSs). TLSs carried prognostic benefit only in the presence of CXCL13. CXCL13 in combination with anti-PD-1 therapy retarded tumor growth in a CD8+ T-cell-dependent manner, resulting in increased infiltration of cytotoxic CD8+ T cells and CXCR5+CD8+ T cells.ConclusionsThese data define a critical role of CXCL13 in shaping antitumor microenvironment by facilitating the maintenance of CXCR5+CD8+ T cells in TLSs and support a clinical investigation for a combination of CXCL13 and PD-1 blockade therapy in HGSC.

scholarly journals Ex vivo modelling of PD-1/PD-L1 immune checkpoint blockade under acute, chronic, and exhaustion-like conditions of T-cell stimulation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alexander Roberts ◽  
Lindsay Bentley ◽  
Tina Tang ◽  
Fay Stewart ◽  
Chiara Pallini ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Immune Checkpoint ◽  
Inflammatory Cytokine ◽  
Cell Activation ◽  
Ex Vivo ◽  
In Vitro Assays ◽  
The Impact

AbstractBlockade of PD-1/PD-L1 interactions is proving an exciting, durable therapeutic modality in a range of cancers whereby T cells are released from checkpoint inhibition to revive their inherent anti-tumour activity. Here we have studied various ways to model ex vivo T cell function in order to compare the impact of the clinically utilised anti-PD-1 antibody, pembrolizumab (Keytruda) on the activation of human T cells: focussing on the release of pro-inflammatory IFNγ and anti-inflammatory IL-10 to assess functionality. Firstly, we investigated the actions of pembrolizumab in an acute model of T-cell activation with either immature or mature allogeneic dendritic cells (DCs); pembrolizumab enhanced IFNγ and IL-10 release from purified CD4+ T-cells in the majority of donors with a bias towards pro-inflammatory cytokine release. Next, we modelled the impact of pembrolizumab in settings of more chronic T-cell activation. In a 7-day antigen-specific response to EBV peptides, the presence of pembrolizumab resulted in a relatively modest increase in both IFNγ and IL-10 release. Where pembrolizumab was assessed against long-term stimulated CD4+ cells that had up-regulated the exhaustion markers TIM-3 and PD-1, there was a highly effective enhancement of the otherwise exhausted response to allogeneic DCs with respect to IFNγ production. By contrast, the restoration of IL-10 production was considerably more limited. Finally, to assess a direct clinical relevance we investigated the consequence of PD-1/PD-L1 blockade in the disease setting of dissociated cells from lung and colon carcinomas responding to allogeneic DCs: here, pembrolizumab once more enhanced IFNγ production from the majority of tumour preparations whereas, again, the increase in IL-10 release was modest at best. In conclusion, we have shown that the contribution of PD-1—revealed by using a canonical blocking antibody to interrupt its interaction with PD-L1—to the production of an exemplar pro- and anti-inflammatory cytokine, respectively, depends in magnitude and ratio on the particular stimulation setting and activation status of the target T cell. We have identified a number of in vitro assays with response profiles that mimic features of dissociated cell populations from primary tumours thereby indicating these represent disease-relevant functional assays for the screening of immune checkpoint inhibitors in current and future development. Such in vitro assays may also support patient stratification of those likely to respond to immuno-oncology therapies in the wider population.

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