scholarly journals Combination of a T cell activating therapy and anti-phosphatidylserine enhances anti-tumour immune responses in a HPV16 E7-expressing C3 tumour model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Brennan S. Dirk ◽  
Genevieve Weir ◽  
Tara Quinton ◽  
Olga Hrytsenko ◽  
Marianne M. Stanford

AbstractDPX is a novel delivery platform that generates targeted CD8 + T cells and drives antigen-specific cytotoxic T cells into tumours. Cancer cells upregulate phosphatidylserine (PS) on the cell surface as a mechanism to induce an immunosuppressive microenvironment. Development of anti-PS targeting antibodies have highlighted the ability of a PS-blockade to enhance tumour control by T cells by releasing immunosuppression. Here, C57BL/6 mice were implanted with HPV16 E7 target-expressing C3 tumours and subjected to low dose intermittent cyclophosphamide (CPA) in combination with DPX-R9F treatment targeting an E7 antigen with and without anti-PS and/or anti-PD-1 targeting antibodies. Immune responses were assessed via IFN-γ ELISPOT assay and the tumour microenvironment was further analyzed using RT-qPCR. We show that the combination of DPX-R9F and PS-targeting antibodies with and without anti-PD-1 demonstrated increased efficacy compared to untreated controls. All treatments containing DPX-R9F led to T cell activation as assessed by IFN-γ ELISPOT. Furthermore, DPX-R9F/anti-PS treatment significantly elevated cytotoxic T cells, macrophages and dendritic cells based on RT-qPCR analysis. Overall, our data indicates that anti-tumour responses are driven through a variety of immune cells within this model and highlights the need to investigate combination therapies which increase tumour immune infiltration, such as anti-phosphotidylserine.

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 764-764 ◽  
Author(s):  
Felix S. Lichtenegger ◽  
Katrin Deiser ◽  
Maurine Rothe ◽  
Frauke M. Schnorfeil ◽  
Christina Krupka ◽  
...  

Abstract Postremission therapy is critical for successful elimination of minimal residual disease (MRD) in acute myeloid leukemia (AML). Innovative treatment options are needed for patients that are not eligible for allogeneic stem cell transplantation. As the intrinsic immune response against leukemia-associated antigens (LAAs) is generally low, the clinical application of checkpoint inhibitors as monotherapy is less promising in AML compared to other hemato-oncological diseases. Therapeutic vaccination with autologous dendritic cells (DCs) loaded with LAAs is a promising treatment strategy to induce anti-leukemic immune responses. We have conducted a phase I/II proof-of-concept study using monocyte-derived next-generation DCs as postremission therapy of AML patients with a non-favorable risk profile in CR/CRi after intensive induction therapy (NCT01734304). These DCs are generated using a GMP-compliant 3-day protocol including a TLR7/8 agonist, loaded with RNA encoding the LAAs WT1 and PRAME as well as CMVpp65 as adjuvant/surrogate antigen, and are applied intradermally up to 10 times within 26 weeks. The primary endpoint of the trial is feasibility and safety of the vaccination. Secondary endpoints are immunological responses and disease control. After the safety and toxicity profile was evaluated within phase I (n=6), the patient cohort was expanded to a total of 13 patients. DCs of sufficient number and quality could be generated from leukapheresis in 11/12 cases. DCs exhibited an immune-stimulatory profile based on high costimulatory molecule expression, IL-12p70 secretion, migration towards a chemokine gradient and processing and presentation of antigen. In 9/9 patients that are currently evaluable, we observed delayed-type hypersensitivity (DTH) responses at the vaccination site, but no grade III/IV toxicities. TCR repertoire analysis by next-generation sequencing revealed an enrichment of particular clonotypes at DTH sites. In the peripheral blood, we detected vaccination-specific T cell responses by multimer staining and by ELISPOT analysis: 7/7 patients showed responses to CMVpp65, including both boosting of pre-existing T cells in CMV+ patients and induction of a primary T cell response in CMV- patients. 2/7 patients exhibited responses to PRAME and WT each. 7/10 vaccinated patients are still alive, and 5/10 are in CR, with an observation period of up to 840 days. In vitro, DC-activated T cells showed an upregulation of PD-1 and LAG-3, while the DCs expressed the respective ligands PD-L1 and HLA-DR. Therefore, we studied the capacity of checkpoint blocking antibodies to further enhance T-cell activation by DCs. We found that blockade of PD-1 and particularly of LAG-3 was highly effective in enhancing both IFN-γ secretion and proliferation of T cells. Both pathways seem to target different T-cell subsets, as PD-1 blockade resulted in increased IFN-γ secretion by TN- and TEM-subsets, while blockade of LAG-3 significantly affected TN- and TCM-subsets. We conclude that vaccination with next-generation LAA-expressing DCs in AML is feasible, safe, and induces anti-leukemic immune responses in vivo. Our in vitro data supports the hypothesis that T-cell activation by means of the vaccine could be further enhanced by blocking PD-1 and/or LAG-3. Disclosures Subklewe: AMGEN Research Munich: Research Funding.


Author(s):  
Yan Yan ◽  
Wei Zhao ◽  
Wei Liu ◽  
Yan Li ◽  
Xu Wang ◽  
...  

Abstract Background Chemokine (C–C motif) ligand 19 (CCL19) is a leukocyte chemoattractant that plays a crucial role in cell trafficking and leukocyte activation. Dysfunctional CD8+ T cells play a crucial role in persistent HBV infection. However, whether HBV can be cleared by CCL19-activated immunity remains unclear. Methods We assessed the effects of CCL19 on the activation of PBMCs in patients with HBV infection. We also examined how CCL19 influences HBV clearance and modulates HBV-responsive T cells in a mouse model of chronic hepatitis B (CHB). In addition, C–C chemokine-receptor type 7 (CCR7) knockdown mice were used to elucidate the underlying mechanism of CCL19/CCR7 axis-induced immune activation. Results From in vitro experiments, we found that CCL19 enhanced the frequencies of Ag-responsive IFN-γ+ CD8+ T cells from patients by approximately twofold, while CCR7 knockdown (LV-shCCR7) and LY294002 partially suppressed IFN-γ secretion. In mice, CCL19 overexpression led to rapid clearance of intrahepatic HBV likely through increased intrahepatic CD8+ T-cell proportion, decreased frequency of PD-1+ CD8+ T cells in blood and compromised suppression of hepatic APCs, with lymphocytes producing a significantly high level of Ag-responsive TNF-α and IFN-γ from CD8+ T cells. In both CCL19 over expressing and CCR7 knockdown (AAV-shCCR7) CHB mice, the frequency of CD8+ T-cell activation-induced cell death (AICD) increased, and a high level of Ag-responsive TNF-α and low levels of CD8+ regulatory T (Treg) cells were observed. Conclusions Findings in this study provide insights into how CCL19/CCR7 axis modulates the host immune system, which may promote the development of immunotherapeutic strategies for HBV treatment by overcoming T-cell tolerance.


1996 ◽  
Vol 184 (2) ◽  
pp. 753-758 ◽  
Author(s):  
X G Tai ◽  
Y Yashiro ◽  
R Abe ◽  
K Toyooka ◽  
C R Wood ◽  
...  

Costimulation mediated by the CD28 molecule plays an important role in optimal activation of T cells. However, CD28-deficient mice can mount effective T cell-dependent immune responses, suggesting the existence of other costimulatory systems. In a search for other costimulatory molecules on T cells, we have developed a monoclonal antibody (mAb) that can costimulate T cells in the absence of antigen-presenting cells (APC). The molecule recognized by this mAb, 9D3, was found to be expressed on almost all mature T cells and to be a protein of approximately 24 kD molecular mass. By expression cloning, this molecule was identified as CD9, 9D3 (anti-CD9) synergized with suboptimal doses of anti-CD3 mAb in inducing proliferation by virgin T cells. Costimulation was induced by independent ligation of CD3 and CD9, suggesting that colocalization of these two molecules is not required for T cell activation. The costimulation by anti-CD9 was as potent as that by anti-CD28. Moreover, anti-CD9 costimulated in a CD28-independent way because anti-CD9 equally costimulated T cells from the CD28-deficient as well as wild-type mice. Thus, these results indicate that CD9 serves as a molecule on T cells that can deliver a potent CD28-independent costimulatory signal.


1993 ◽  
Vol 177 (6) ◽  
pp. 1791-1796 ◽  
Author(s):  
F A Harding ◽  
J P Allison

The activation requirements for the generation of CD8+ cytotoxic T cells (CTL) are poorly understood. Here we demonstrate that in the absence of exogenous help, a CD28-B7 interaction is necessary and sufficient for generation of class I major histocompatibility complex-specific CTL. Costimulation is required only during the inductive phase of the response, and not during the effector phase. Transfection of the CD28 counter receptor, B7, into nonstimulatory P815 cells confers the ability to elicit P815-specific CTL, and this response can be inhibited by anti-CD28 Fab or by the chimeric B7-binding protein CTLA4Ig. Anti-CD28 monoclonal antibody (mAb) can provide a costimulatory signal to CD8+ T cells when the costimulatory capacity of splenic stimulators is destroyed by chemical fixation. CD28-mediated signaling provokes the release of interleukin 2 (IL-2) from the CD8+ CTL precursors, as anti-CD28 mAb could be substituted for by the addition of IL-2, and an anti-IL-2 mAb can block the generation of anti-CD28-induced CTL. CD4+ cells are not involved in the costimulatory response in the systems examined. We conclude that CD8+ T cell activation requires two signals: an antigen-specific signal mediated by the T cell receptor, and an additional antigen nonspecific signal provided via a CD28-B7 interaction.


Cancers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 3948
Author(s):  
Kazumasa Oya ◽  
Yoshiyuki Nakamura ◽  
Zhu Zhenjie ◽  
Ryota Tanaka ◽  
Naoko Okiyama ◽  
...  

The exact mechanisms of the imiquimod (IMQ)-induced antitumor effect have not been fully understood. Although both topical IMQ treatment and anti-PD-1 antibody may be used for primary skin lesions or skin metastases of various cancers, the efficacy of each monotherapy for these lesions is insufficient. Using a murine tumor model and human samples, we aimed to elucidate the detailed mechanisms of the IMQ-induced antitumor effect and analyzed the antitumor effect of combination therapy of topical IMQ plus anti-PD-1 antibody. Topical IMQ significantly suppressed the tumor growth of MC38 in wildtype mice. IMQ upregulated interferon γ (IFN-γ) expression in CD8+ T cells in both the lymph nodes and the tumor, and the antitumor effect was abolished in both Rag1-deficient mice and IFN-γ-deficient mice, indicating that IFN-γ produced by CD8+ T cells play a crucial role in the IMQ-induced antitumor effect. IMQ also upregulated PD-1 expression in T cells as well as PD-L1/PD-L2 expression in myeloid cells, suggesting that IMQ induces not only T-cell activation but also T-cell exhaustion by enhanced PD-1 inhibitory signaling. Combination therapy of topical IMQ plus anti-PD-1 antibody exerted a significantly potent antitumor effect when compared with each single therapy, indicating that the combination therapy is a promising therapy for the skin lesions of various cancers.


2021 ◽  
Vol 478 (22) ◽  
pp. 3999-4004
Author(s):  
Lawrence P. Kane

Tim-3 is a transmembrane protein that is highly expressed on subsets of chronically stimulated CD4+ helper and CD8+ cytotoxic T cells, with more transient expression during acute activation and infection. Tim-3 is also constitutively expressed by multiple types of myeloid cells. Like other TIM family members, Tim-3 can bind to phosphatidylserine displayed by apoptotic cells, and this interaction has been shown to mediate uptake of such cells by dendritic cells and cross-presentation of antigens to CD8+ T cells. In contrast, how the recognition of PS by Tim-3 might regulate the function of Tim-3+ T cells is not known. In their recent paper, Lemmon and colleagues demonstrate for the first time that recognition of PS by Tim-3 leads to enhanced T cell activation.


Blood ◽  
2012 ◽  
Vol 120 (23) ◽  
pp. 4560-4570 ◽  
Author(s):  
Yuning Lu ◽  
Helga Schneider ◽  
Christopher E. Rudd

Abstract CTLA-4 inhibits T-cell activation and protects against the development of autoimmunity. We and others previously showed that the coreceptor can induce T-cell motility and shorten dwell times with dendritic cells (DCs). However, it has been unclear whether this property of CTLA-4 affects both conventional T cells (Tconvs) and regulatory T cells (Tregs). Here, we report that CTLA-4 had significantly more potent effects on the motility and contact times of Tconvs than Tregs. This was shown firstly by anti–CTLA-4 reversal of the anti-CD3 stop-signal on FoxP3-negative cells at concentrations that had no effect on FoxP3-positive Tregs. Secondly, the presence of CTLA-4 reduced the contact times of DO11.10 x CD4+CD25− Tconvs, but not DO11.10 x CD4+CD25+ Tregs, with OVA peptide presenting DCs in lymph nodes. Thirdly, blocking of CTLA-4 with anti–CTLA-4 Fab increased the contact times of Tconvs, but not Tregs with DCs. By contrast, the presence of CD28 in a comparison of Cd28−/− and Cd28+/+ DO11.10 T cells had no detectable effect on the contact times of either Tconvs or Tregs with DCs. Our findings identify for the first time a mechanistic explanation to account for CTLA-4–negative regulation of Tconv cells but not Tregs in immune responses.


Blood ◽  
1999 ◽  
Vol 93 (3) ◽  
pp. 886-896 ◽  
Author(s):  
David Sancho ◽  
Marı́a Yáñez-Mó ◽  
Reyes Tejedor ◽  
Francisco Sánchez-Madrid

Abstract Cell adhesion molecules have a key role in the migration of T cells to inflammatory foci. However, the effect of the endothelial-lymphocyte interaction on the activation of the latter cells remains unresolved. We have studied the effect of resting and stimulated endothelial cells (ECs) on the activation of peripheral blood T cells (PBTLs), as assessed by the expression of CD69 and CD25 activation antigens. The incubation of PBTLs with tumor necrosis factor-–activated EC monolayers, either alive or fixed, induced the expression of CD69 but not CD25, preferentially in the CD8+CD45RO+ cell subset. Furthermore, it induced the production of cytokines such as IFN-γ, but not that of interleukin-2 (IL-2) and IL-4. EC treated with other stimuli such as IL-1β, IFN-γ, or lipopolysaccharide also showed the same proactivatory effect on T cells. Lymphocyte activation was almost completely inhibited by blocking anti-CD18 and anti–intercellular adhesion molecule-1 (anti–ICAM-1) monoclonal antibodies (MoAbs), but only slightly affected by MoAbs against CD49d, vascular cell adhesion molecule-1, and anti–IL-15. In addition, the interaction of PBTL with immobilized ICAM-1 induced CD69 expression in the same memory T-cell subset. IL-15 induced T-cell activation with expression of CD69 and CD25, and production of IFN-γ, and its effect was additive with that triggered by cell adhesion to either EC or immobilized ICAM-1. The transmigration of PBTLs through either confluent EC monolayers or ICAM-1–coated membranes also induced efficiently the expression of CD69. When IL-15 was used as chemoattractant in these assays, a further enhancement in CD69 expression was observed in migrated cells. Together these results indicate that stimulated endothelium may have an important role in T-cell activation, through the lymphocyte function antigen-1/ICAM-1 pathway, and that IL-15 efficiently cooperates in this phenomenon. These observations could account for the abundance of CD69+ cells in the lymphocytic infiltrates of several chronic inflammatory diseases.


2017 ◽  
Vol 91 (23) ◽  
Author(s):  
Ulrike Sauermann ◽  
Antonia Radaelli ◽  
Nicole Stolte-Leeb ◽  
Katharina Raue ◽  
Massimiliano Bissa ◽  
...  

ABSTRACT An effective AIDS vaccine should elicit strong humoral and cellular immune responses while maintaining low levels of CD4+ T-cell activation to avoid the generation of target cells for viral infection. The present study investigated two prime-boost regimens, both starting vaccination with single-cycle immunodeficiency virus, followed by two mucosal boosts with either recombinant adenovirus (rAd) or fowlpox virus (rFWPV) expressing SIVmac239 or SIVmac251 gag/pol and env genes, respectively. Finally, vectors were switched and systemically administered to the reciprocal group of animals. Only mucosal rFWPV immunizations followed by systemic rAd boost significantly protected animals against a repeated low-dose intrarectal challenge with pathogenic SIVmac251, resulting in a vaccine efficacy (i.e., risk reduction per exposure) of 68%. Delayed viral acquisition was associated with higher levels of activated CD8+ T cells and Gag-specific gamma interferon (IFN-γ)-secreting CD8+ cells, low virus-specific CD4+ T-cell responses, and low Env antibody titers. In contrast, the systemic rFWPV boost induced strong virus-specific CD4+ T-cell activity. rAd and rFWPV also induced differential patterns of the innate immune responses, thereby possibly shaping the specific immunity. Plasma CXCL10 levels after final immunization correlated directly with virus-specific CD4+ T-cell responses and inversely with the number of exposures to infection. Also, the percentage of activated CD69+ CD8+ T cells correlated with the number of exposures to infection. Differential stimulation of the immune response likely provided the basis for the diverging levels of protection afforded by the vaccine regimen. IMPORTANCE A failed phase II AIDS vaccine trial led to the hypothesis that CD4+ T-cell activation can abrogate any potentially protective effects delivered by vaccination or promote acquisition of the virus because CD4+ T helper cells, required for an effective immune response, also represent the target cells for viral infection. We compared two vaccination protocols that elicited similar levels of Gag-specific immune responses in rhesus macaques. Only the animal group that had a low level of virus-specific CD4+ T cells in combination with high levels of activated CD8+ T cells was significantly protected from infection. Notably, protection was achieved despite the lack of appreciable Env antibody titers. Moreover, we show that both the vector and the route of immunization affected the level of CD4+ T-cell responses. Thus, mucosal immunization with FWPV-based vaccines should be considered a potent prime in prime-boost vaccination protocols.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 951-951
Author(s):  
Ettore Biagi ◽  
Giampietro Dotti ◽  
Eric Yvon ◽  
Raphael Rousseau ◽  
Edward Lee ◽  
...  

Abstract CD40 ligand is an accessory signal for T-cell activation and can overcome T-cell anergy. The OX40-OX40 ligand pathway is involved in the subsequent expansion of memory T cells. We expressed both human CD40L and OX40L on B-Chronic Lymphocytic Leukemia (B-CLL) cells, by exploiting the phenomenon of molecular transfer from fibroblasts engineered to over-express both of these TNF-receptor superfamily members. We analyzed the effects of the modified B-CLL cells on the number, phenotype and cytotoxic function of autologous T cells in seven B-CLL patients. Transfer of CD40L and OX40L to B-CLL cells was observed in all patients (mean value from 1% pre to 76% post for CD40L; from 0.7% pre to 88% post for OX40L). Subsequent up-regulation of the costimulatory molecules CD80 (B7-1) and CD86 (B7-2) was obtained after engagement of the endogenous CD40 receptor on B-CLL by the transferred CD40L molecules (mean value from 8% pre to 64% post for CD80; from 36% pre to 95% post for CD86). Co-culture of modified and unmodified B-CLL cells with autologous T cells revealed profound differences in the immune responses they induced. With unmodified B-CLL cells, or cells expressing either CD40L or OX40L individually, less than a 10-fold expansion of autologous T cells was observed, with a <100-fold expansion in tumor reactive T cells (measured by IFN-gamma Elispot with autologous B-CLL cells as stimulators, and allogeneic B-CLL cells as controls). By contrast, co-culture with B-CLL cells expressing both CD40L and OX40L induced a >40 fold expansion of autologous T cells - including both CD8+ T cells and CD4+ T cells with a Th1 pattern of cytokine release - and a >2500-fold increase in leukemia-reactive T cells. These expanded T cells were also directly cytotoxic to B-CLL targets, producing a mean 48% B-CLL killing at an E:T ratio of 10:1. A proportion of these tumor-reactive CD8+ T cells were specific for survivin, a B-CLL associated tumor antigen. Hence the combination of CD40L and OX40L expression by B-CLL cells allows generation of potent immune responses to B-CLL, which may be exploitable either by using active immunization with CD40L/OX40L-modified tumor cells or by adoptive immunotherapy with CD40L/OX40L generated tumor-reactive T cells.


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