scholarly journals Proliferating CD8+ T Cell Infiltrates Are Associated with Improved Survival in Glioblastoma

Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3378
Author(s):  
Ileana S. Mauldin ◽  
Jasmin Jo ◽  
Nolan A. Wages ◽  
Lalanthica V. Yogendran ◽  
Adela Mahmutovic ◽  
...  

Background: tumor-infiltrating lymphocytes are prognostic in many human cancers. However, the prognostic value of lymphocytes infiltrating glioblastoma (GBM), and roles in tumor control or progression are unclear. We hypothesized that B and T cell density, and markers of their activity, proliferation, differentiation, or function, would have favorable prognostic significance for patients with GBM. Methods: initial resection specimens from 77 patients with IDH1/2 wild type GBM who received standard-of-care treatment were evaluated with multiplex immunofluorescence histology (mIFH), for the distribution, density, differentiation, and proliferation of T cells and B cells, as well as for the presence of tertiary lymphoid structures (TLS), and IFNγ expression. Immune infiltrates were evaluated for associations with overall survival (OS) by univariate and multivariate Cox proportional hazards modeling. Results: in univariate analyses, improved OS was associated with high densities of proliferating (Ki67+) CD8+ cells (HR 0.36, p = 0.001) and CD20+ cells (HR 0.51, p = 0.008), as well as CD8+Tbet+ cells (HR 0.46, p = 0.004), and RORγt+ cells (HR 0.56, p = 0.04). Conversely, IFNγ intensity was associated with diminished OS (HR 0.59, p = 0.036). In multivariable analyses, adjusting for clinical variables, including age, resection extent, Karnofsky Performance Status (KPS), and MGMT methylation status, improved OS was associated with high densities of proliferating (Ki67+) CD8+ cells (HR 0.15, p < 0.001), and higher ratios of CD8+ cells to CD4+ cells (HR 0.31, p = 0.005). Diminished OS was associated with increases in patient age (HR 1.21, p = 0.005) and higher mean intensities of IFNγ (HR 2.13, p = 0.027). Conclusions: intratumoral densities of proliferating CD8 T cells and higher CD8/CD4 ratios are independent predictors of OS in patients with GBM. Paradoxically, higher mean intensities of IFNγ in the tumors were associated with shorter OS. These findings suggest that survival may be enhanced by increasing proliferation of tumor-reactive CD8+ T cells and that approaches may be needed to promote CD8+ T cell dominance in GBM, and to interfere with the immunoregulatory effects of IFNγ in the tumor microenvironment.

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A696-A696
Author(s):  
Teresa Manzo ◽  
Carina Nava Lauveson ◽  
Teresa Maria Frasconi ◽  
Silvia Tiberti ◽  
Ignazio Caruana ◽  
...  

BackgroundAdoptive cell therapy (ACT) harnesses the immune system to recognise tumor cells and carry out an anti-tumor function. However, metabolic constraints imposed by the tumour microenvironment (TME) suppress anti-tumor responses of CTL by reshaping their metabolism and epigenetic landscape. We have recently demonstrated that progressive accumulation of specific long-chain fatty acids (LCFAs) impair mitochondrial function and drives CD8+ T cell dysfunction. In this scenario, maintaining T cells in a less-differentiated state and with high metabolic plasticity during ex vivo T cell production and after infusion may have a strong therapeutic impact. Here, we propose a novel strategy to boost ACT efficacy by implementing T cell long-term functionality, metabolic fitness and preventing exhaustion through lipid-induced mitochondrial rewiring.MethodsWe screen different LCFAs and assess their ability to shape CD8+ T cell differentiation using multi-parametric flow cytometry, proliferation and cytotoxic assays, together with a complete transcriptomic and epigenomic profiling. Metabolic reprogramming of lipid-treated CD8+ T cell was examined by bioenergetic flux measurements paired with metabolomic and lipidomic analysis. Finally, the anti-tumor responses of lipid-instructed CD8 T cells was evaluated in a melanoma mouse model, known to poorly respond to immunotherapy.ResultsLCFAs-treated CD8+ T cells are endowed with highly effector and cytotoxic features but still retaining a memory-like phenotype with decreased PD1 protein levels. Consistently, analysis of the bioenergetic profile and mitochondrial activity has shown that LCFA-instructed CD8+ T cells display a greater mitochondrial fitness. Thus, in vitro LCFA-instructed CD8+ T cells are characterized by higher mitochondrial fitness, potent functionality, memory-like phenotype and PD-1 down-regulation, overall evoking the ideal T cell population associated with a productive anti-tumor response. The therapeutic potential of CD8 T cells lipid-induced metabolic rewiring was further confirmed in vivo. ACT performed with LCFA-reprogrammed CD8 T cells induces higher frequency of memory T cells, which show high polyfunctionality and mitochondrial function, decreased PD1 expression, ultimately resulting in improved tumor control. In addition, LCFA-induced metabolic rewiring during manufacturing of human CAR-redirected T cells, generated a CD8+ T cell memory-like population with higher mitochondrial fitness coupled with a much potent cytotoxic activity.ConclusionsThese results suggest that LCFAs dictate the fate of CD8+ T cell differentiation and could be considered as a molecular switch to fine-tune memory T cell formation and metabolic fitness maintenance, linking lipid metabolism to anti-tumor surveillance. This will be of fundamental importance for a new generation of adoptive T cell-based therapies.Ethics ApprovalThe experiments described were performed in accordance with the European Union Guideline on Animal Experiments and mouse protocols were approved by Italian Ministry of Health and the IEO Committee.


1999 ◽  
Vol 190 (9) ◽  
pp. 1275-1284 ◽  
Author(s):  
Leo Lefrançois ◽  
Sara Olson ◽  
David Masopust

The role of CD40 ligand (CD40L) in CD8 T cell activation was assessed by tracking antigen-specific T cells in vivo using both adoptive transfer of T cell receptor transgenic T cells and major histocompatibility complex (MHC) class I tetramers. Soluble antigen immunization induced entry of CD8 cells into the intestinal mucosa and cytotoxic T lymphocyte (CTL) differentiation, whereas CD8 cells in secondary lymphoid tissue proliferated but were not cytolytic. Immunization concurrent with CD40L blockade or in the absence of CD40 demonstrated that accumulation of CD8 T cells in the mucosa was CD40L dependent. Furthermore, activation was mediated through CD40L expressed by the CD8 cells, since inhibition by anti-CD40L monoclonal antibodies occurred after adoptive transfer to CD40L-deficient mice. However, mucosal CD8 T cells in normal and CD40−/− mice were equivalent killers, indicating that CD40L was not required for CTL differentiation. Appearance of virus-specific mucosal, but not splenic, CD8 cells also relied heavily on CD40–CD40L interactions. The mucosal CTL response of transferred CD8 T cells was MHC class II and interleukin 12 independent. The results established a novel pathway of direct CD40L-mediated CD8 T cell activation.


Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1263
Author(s):  
Paytsar Topchyan ◽  
Gang Xin ◽  
Yao Chen ◽  
Shikan Zheng ◽  
Robert Burns ◽  
...  

In cancer, CD8+ T cells enter a dysfunctional state which prevents them from effectively targeting and killing tumor cells. Tumor-infiltrating CD8+ T cells consist of a heterogeneous population of memory-like progenitor, effector, and terminally exhausted cells that exhibit differing functional and self-renewal capacities. Our recently published work has shown that interleukin (IL)-21-producing CD4+ T cells help to generate effector CD8+ T cells within the tumor, which results in enhanced tumor control. However, the molecular mechanisms by which CD4+ helper T cells regulate the differentiation of effector CD8+ T cells are not well understood. In this study, we found that Basic Leucine Zipper ATF-Like Transcription Factor (BATF), a transcription factor downstream of IL-21 signaling, is critical to maintain CD8+ T cell effector function within the tumor. Using mixed bone marrow chimeras, we demonstrated that CD8+ T cell-specific deletion of BATF resulted in impaired tumor control. In contrast, overexpressing BATF in CD8+ T cells enhanced effector function and resulted in improved tumor control, bypassing the need for CD4+ helper T cells. Transcriptomic analyses revealed that BATF-overexpressing CD8+ T cells had increased expression of costimulatory receptors, effector molecules, and transcriptional regulators, which may contribute to their enhanced activation and effector function. Taken together, our study unravels a previously unappreciated CD4+ T cell-derived IL-21–BATF axis that could provide therapeutic insights to enhance effector CD8+ T cell function to fight cancer.


2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A326-A326
Author(s):  
Brendan Horton ◽  
Duncan Morgan ◽  
Elen Torres-Mejia ◽  
Maria Zagorulya ◽  
Vidit Bhandarkar ◽  
...  

BackgroundIn non-small cell lung cancer (NSCLC), response to checkpoint blockade therapy (CBT) is associated with tumor-infiltrating CD8+ T cells, but not all T cell-infiltrated tumors respond to CBT. The subgroup of T cell-infiltrated but CBT-resistant tumors has been clinically described as containing ”non-functional” T cell responses. Mechanisms governing the generation of non-functional T cell responses remain poorly understood, and treatment options for this subgroup are limited.MethodsWe utilized a transplantable, syngeneic murine NSCLC cell line derived from an autochthonous NSCLC driven by KrasG12D expression and p53 deletion (KP cell line) to model non-functional T cell responses. To study antigen-specific responses, we engineered KP cells to express the model CD8+ T cell antigen SIY for certain experiments. CBT consisted of combined anti-CTLA-4 and anti-PD-L1 therapy.ResultsOrthotopic KP lung tumors failed to respond to CBT, but KP flank tumors were controlled by CBT. Lung and flank tumors contained activated CD8+ T cells, providing a platform to compare functional and non-functional CD8+ T cell responses in NSCLC. Single-cell RNA sequencing revealed that lung tumor-infiltrating CD8+ T cells lacked effector and exhaustion molecules despite clonal expansion. Analysis of antigen-specific CD8+ T cells revealed that this lung cancer-specific T cell dysfunction was established during priming in lung-draining mediastinal lymph nodes (mLN) despite robust T cell proliferation. RNA sequencing and flow cytometry of antigen-specific CD8+ T cells found that T cells primed in the mLN underwent blunted effector differentiation characterized by a lack of effector molecules CD25, Granzyme B, and TIM-3, but retention of TCF-1. This phenotype persisted in lung tumors, consistent with our initial observations of absent effector and exhaustion molecule expression. Many CD8+ T cells from NSCLC patients expressed an analogous gene expression program distinct from T cell exhaustion. TCF-1+ CD8+ T cells in lung tumors did not mediate tumor control and failed to differentiate into effector cells after CBT. To investigate alternative therapeutic strategies of reinvigorating lung tumor-reactive T cells, we focused on IL-2 and IL-12, as expression of their receptors was reduced in mLN-primed T cells. Administering recombinant IL-2 and IL-12 was sufficient to restore effector T cell differentiation, induce lung tumor control, and significantly extend survival of lung tumor-bearing mice.ConclusionsOur results suggest that non-functional CD8+ T cell responses in NSCLC arise from failed effector T cell differentiation during priming. Transient combination therapy with IL-2 and IL-12 overcomes this dysfunctional state to induce protective T cell responses in CBT-resistant tumors.Ethics ApprovalAll mouse experiments were approved by MIT’s Committee on Animal Care (CAC) - DHHS Animal Welfare Assurance # D16-00078


2020 ◽  
Author(s):  
Alexandros Lalos ◽  
Ali Tülek ◽  
Nadia Tosti ◽  
Robert Mechera ◽  
Alexander Wilhelm ◽  
...  

Abstract Background: Since colorectal cancer (CRC) remains one of the most common malignancies, a tremendous amount of studies keep taking place in this field. Over the past 25 years, a notable part of the scientific community has focused on the association between the immune system and colorectal cancer. A variety of studies have shown that high densities of infiltrating CD8+ T cells are associated with improved disease-free and overall survival in colorectal cancer (CRC). Stromal cell-derived factor-1 (SDF-1) is a protein that regulates leukocyte trafficking and is variably expressed in several healthy and malignant tissues. There is strong evidence that SDF-1 has a negative prognostic impact on colorectal cancer (CRC). However, based on a significant correlation of SDF-1 and CD8+ T cells in a previous study (r=0.53, p<0.0001), we hypothesized that the prognostic significance of SDF-1 in CRC could depend on the immune microenvironment. Therefore, we explored the combined prognostic significance of SDF-1 expression and CD8+ T cell density in a large CRC collective. Methods: We analyzed a tissue microarray (TMA) of 613 patient specimens of primary CRCs by immunohistochemistry (IHC) for the expression of SDF-1 by tumor cells and tumor-infiltrating immune cells (TICs) and CD8+ T-cells. Besides, we analyzed the expression of SDF-1 at the RNA level in The Cancer Genome Atlas cohort (TCGA). Results: We found that the the combined high expression of SDF-1 and CD8+ T-cell infiltration shows a favorable 5-year overall survival rate (66%; 95%CI=48–79%) compared to tumors showing a high expression of CD8+ T-cells only (55%; 95%CI=45–64%; p=0.0004). High expression of SDF-1 and CD8+ T-cells infiltration was significantly associated with a favorable prognosis also in a validation group (p=0.016). Univariate and multivariate Hazard Cox regression survival analysis considering the combination of both markers revealed that the combined high expression of SDF-1 and CD8+ T cells was an independent, favorable, prognostic marker for overall survival (HR=0.34, 95%CI=0.17–0.66; p=0.002 and HR=0.45, 95%CI=0.23–0.89; p=0.021, respectively). In a spearman’s correlation analysis from the TCGA cohort, SDF-1 also correlated significantly with CD8+ T cells (r=0.28). Conclusions: SDF-1 high /CD8 high density represents an independent, favorable, prognostic condition in CRC, most likely due to an effective antigen-specific immune response.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2186-2186
Author(s):  
Michiyo Ohyashiki ◽  
Junko H Ohyashiki ◽  
Ayako Hirota ◽  
Chiaki Kobayashi ◽  
Kazuma Ohyashiki

Abstract Abstract 2186 Background and Aim: MicroRNAs (miRNAs) consist of short noncoding RNA molecules of approximately 18–22 nucleotide that regulate post-transcriptional gene expression by degradation or repression of mRNA molecules. The miR-17-92a cluster is known as a regulator of the immune system and is critical for lymphoid cellular development and tumorigenesis in lymphoid tissue. Most knowledge of the miR-17-92 cluster in normal and abnormal conditions of the lymphoid system is based on mouse experiments. It is suggested that the accumulation of activated CD4+ T cells by higher mir-17-92 expression leads to a breakdown of T-cell tolerance in the periphery and may promote B-cell activation, germinal center reaction and autoantibody generation. However, only limited reports on in vivo human lymphocyte senescence exist. We therefore set out to determine miR-92a levels in circulating lymphocytes obtained from healthy participants to ascertain the possible association between immunological condition and the expression level of miR-17-92. Experimental design: We separated lymphocytes from 21 healthy volunteers, aged 23 to 58 years (13 men and 8 women), for surface marker and miR-92a level analyses. The CD4+ or CD8+ T-cell fractions were separated with an isolation kit for humans (Miltenyi Biotec, Bergisch Gladbach, Germany) and AutoMACS Pro Separator (Miltenyi Biotec), according to the supplier's instruction, and stored at −80°C until utilization. After separation of CD4+ or CD8+ cells, the miR-92a levels were measure, as reported previously (PLoS ONE. 2011, 24;6(2);e16408). Immunophenotyping was done with flow cytometry. Results: The miR-92a of separated CD8+ lymphocytes decreased significantly with age (P = 0.0002), and miR-92a in CD4+ cells tended to decrease with age (P = 0.0635). We found a positive correlation between CD8+ miR-92a expression level and the percentage of naive CD8+ T cells (RO−CD8+CD27+ cells (P = 0.0046)) with L-selectin antigen (CD3+CD8+CD62L+ (P = 0.0011)) in healthy subjects. This suggests that the miR-92a of a majority of CD8+ T is derived from naive CD8+ T cells with L-selectin antigen, and CD8+ miR-92a expression level declines progressively with age (P < 0.0001 and P < 0.0001, respectively). In CD4+ cells, we observed a trend of decreasing CD4+ miR-92a level with age, while no significant difference was notable with lymphocyte subset fraction as far as we tested. The index of CD8+ miR-92a values (CD8+ miR-92a×number of CD8 cells) was positively correlated with the index of CD4+ miR-92a values (P = 0.0101). Discussion: These results indicate an age-related reduction of naive T cells may link to miR-92a of T-lymphocytes and may influence immune dysfuction with age. In conclusion, our results suggest that the miR-92a level may represent attrition of naïve CD8+ T cells, possibly due to apoptosis of naïve T cells. Additionally down-regulation of the miR-92a level in individuals older than 40 years may indicate impairment or exhaustion of naïve T-cells linked to immune dysfunction and contributed disease states. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1911-1911
Author(s):  
Barry Flutter ◽  
Noha Edwards ◽  
Lei Zhang ◽  
Shivajanani Sivakumaran ◽  
Michael Croft ◽  
...  

Abstract Abstract 1911 A major limitation of adoptive T cell therapies for cancer is the failure to maintain durable anti-tumor immunity. Graft-versus-tumor responses following bone marrow transplantation (BMT) may only be short-lived due to 1) defects in memory precursor generation and 2) exhaustion of surviving CTL that results from direct recognition of alloantigen upon non-hematopoietic cells {Flutter et al. JCI 2010}. In this study, we have explored the potential for enhancing co-stimulatory signals either alone, or in combination with co-inhibitory PD-1-PD-L1 blockade to improve the long term CTL response. Signalling through OX40, a TNF-receptor family member, has been shown to have an important role in long-term immunity, including an enhancement in the generation of CD8 T cell memory precursors. The mechanisms of action are complex and may include both direct effects on CD8 cells and indirect effects on CD4 helper cells or via inhibition of Treg. In initial experiments, we evaluated the effects of early enforced OX40 co-stimulation following delayed transfer of donor T cells to haplo MHC-mismatched chimeras, 10 weeks following nonmyeloablative BMT. OX40 expression peaked on transferred CD4 and CD8 T cells in the first 1–2 weeks following transfer and was sustained thereafter, especially in the CD4 subset. 48 hours after T cell transfer, recipient mice were treated with agonistic anti-OX40 antibody (OX86) or isotype control. OX86 treatment led to a 9-fold increase in the expansion of CTL in comparison to isotype control treated mice, enhanced production of Granzyme B and IFNγ and led to more rapid eradication of host hematopoietic targets or host tumor cells. Moreover, OX86 antibody acted directly on CD8 T cells and bypassed the requirement for help from donor CD4 cells. However, although enforced OX40 co-stimulation boosted the primary effector response, it did not increase numbers of memory precursor cells, as assessed by survival and recall responses following transfer to antigen free hosts, and was unable to prevent eventual exhaustion of surviving donor CTL as tested at 60 days following transfer. Similarly, OX86 was unable to prevent exhaustion of CD8 cells transgenic for the male antigen-specific Matahari (Mh) TCR following adoptive transfer to male BMT recipients reconstituted with female BM. We have shown previously that the functions of exhausted donor CD8 cells are partially restored by blockade of the co-inhibitory PD-1 pathway in both haplo mismatched and MHC-matched mHAg mismatch models. We hypothesized that provision of co-stimulatory signals when exhaustion had become established would increase the effectiveness of co-inhibitory blockade. Therefore, 6 weeks after Mh CD8 T cell transfer to male BMT recipients, we examined the effect of OX86, with or without additional blockade of the PD-1 pathway. Only a minority of Mh CD8 cells from animals receiving isotype control antibody were proliferating in vivo as measured by BrdU incorporation over a 7 day pulse (20 +/−3% BrdU+) and few cells were able to produce IFNγ following antigen stimulation in vitro (3.5+/−1.4 x104 IFNγ+ cells/spleen). OX86 alone offered no restoration of function (15 +/− 2% BrdU+; 3.3+/−0.4 x104 IFNγ+ cells; p=ns). Blockade of PD-L1 modestly increased turnover of cells (37 +/− 6 % BrdU+; p<0.01 vs isotype), but in the absence of CD4 cells, did not significantly increase production of IFNγ (4.4+/−0.9 x104 IFNγ+ cells; p=ns). However, in vivo administration of OX86 combined with anti-PD-L1 blockade dramatically increased turnover of Mh CD8s (77 +/− 8% BrdU+; p<0.001 vs anti-PD-L1 alone, OX86 alone or Isotype) and enhanced their effector function ∼ 9-fold (27.4 +/− 6.8 x104 IFNγ+ cells/spleen; p<0.01 vs all others). In conclusion, forced co-stimulation via OX40 alone is unable either to prevent CTL exhaustion or restore CD8 T cell function when exhaustion has become established. In contrast, the marked synergy observed when agonistic OX40 signals are combined with co-inhibitory blockade, is consistent with a model in which the PD-1 pathway acts at a critical checkpoint that regulates the response to co-stimulation. Thus, these data suggest a novel approach to restoring the functions of exhausted anti-tumor CTL by modulating co-stimulatory and co-inhibitory pathways simultaneously. Disclosures: No relevant conflicts of interest to declare.


2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 3058-3058
Author(s):  
A. D. Cohen ◽  
A. Diab ◽  
M. A. Perales ◽  
F. Duan ◽  
R. Jenq ◽  
...  

3058 Background: Signaling through GITR (glucocorticoid-induced tumor necrosis factor receptor) can abrogate the suppressive effects of CD4+foxp3+ regulatory T cells and co-stimulate activated effector CD4+ and CD8+ T cells. We have previously shown that in vivo GITR ligation using the agonist anti-GITR mAb DTA-1 augments concomitant immunity and immunity generated by active immunization with self- tumor antigens. In the present study, we assessed the activity of anti-GITR mAb used alone, focusing on the effects of GITR ligation on CD8+ T cells during tumor growth. Methods: C57BL/6 mice were injected intradermally with B16 melanoma and received 1mg of DTA-1 or control rat IgG intraperitoneally on various days after tumor injection. In some experiments, naïve, CFSE-labeled pmel-1 CD8+ transgenic T cells (specific for the melanoma antigen gp10025–33 epitope) were transferred into naïve recipients 1 day prior to B16 inoculation. Results: DTA-1 treatment on days 0 and 4 led to tumor rejection in 20–30% and 50–60% of mice, respectively, compared with rejection in 0–5% of mice treated with control IgG (p<0.05 for both). Treatment at day 7 or later had no significant impact on tumor-free survival. The importance of CD8+ T cells in mediating DTA-1-induced tumor immunity was demonstrated by 4 findings: 1) in untreated mice, tumor-infiltrating CD8+ lymphocytes significantly upregulated GITR expression during tumor growth; 2) DTA-1-treated mice had greater CD8+ T cell infiltration into tumors than IgG-treated mice; 3) depletion of CD8+ cells completely abrogated the tumor protection provided by DTA-1; and 4) tumor-specific CD8+ cells proliferated more extensively, became more activated, and exhibited greater effector function following DTA-1 administration compared with control IgG. This was most dramatically seen within the tumor (compared with spleen or draining lymph node), suggesting that a major mechanism of tumor immunity induced by anti-GITR mAb may be overcoming impaired CD8+ T cell function within the tumor microenvironment. Conclusions: Ligating GITR using an agonist mAb can by itself augment tumor-specific CD8+ T cell responses and induce rejection of an aggressive, poorly immunogenic tumor. This strategy merits further consideration as an immune-modulating therapy for cancer. No significant financial relationships to disclose.


2003 ◽  
Vol 198 (11) ◽  
pp. 1759-1764 ◽  
Author(s):  
Byung O. Lee ◽  
Louise Hartson ◽  
Troy D. Randall

Two models have been proposed to explain the requirement for CD40 signaling in CD8 T cell responses. The first model suggests that CD4 T cells activate antigen-presenting cells (APCs) through CD40 signaling (APC licensing). In turn, licensed APCs are able to prime naive CD8 T cells. The second model suggests that CD154-expressing CD4 T cells activate CD40-bearing CD8 T cells directly. Although the requirement for CD40 in APC licensing can be bypassed by inflammatory responses to pathogens that activate APCs directly, the second model predicts that CD8 responses to all antigens will be dependent on CD40 signaling. Here we determined which model applies to CD8 responses to influenza. We demonstrate that optimal CD8 T cell responses to influenza are dependent on CD40 signaling, however both primary and secondary responses to influenza require CD40 expression on non–T cells. Furthermore, CD40−/− CD8 T cells proliferate and differentiate to the same extent as CD40+/+ CD8 T cells in response to influenza, as long as they have equal access to CD40+/+ APCs. Thus, CD4 T cells do not activate influenza-specific CD8 cells directly through CD40 signaling. Instead, these data support the classical model, in which CD4 T cells provide help to CD8 T cells indirectly by activating APCs through CD40.


2020 ◽  
Vol 38 (15_suppl) ◽  
pp. 10038-10038
Author(s):  
Maarten Slagter ◽  
Elisa A. Rozeman ◽  
Huiwen Ding ◽  
Judith M. Versluis ◽  
Mesele Valenti ◽  
...  

10038 Background: Only a subset of advanced melanoma patients respond to anti-PD-1 (aPD1) monotherapy. Upfront identification of (non-)responsiveness would help guide first-line treatment decisions, prevent overtreatment and unnecessary risk for toxicities. T cell density and expression of T cell related genes have been associated with response to aPD1, but are imperfect predictors. We investigated whether spatial proximity of CD8 T cells to tumor cells improves upon the predictive value of T cell density alone. Methods: Pretreatment tumor specimens from melanoma patients treated with aPD1 in the Netherlands Cancer Institute were stained for DAPI, SOX10/Melan-A, CD4, CD8, FOXP3 and PD-1 by multiplex immunofluorescence. Sections were imaged on Vectra and analyzed using HALO to optimize marker thresholds and demarcate tumor and stroma. T cell proximity to tumor cells was evaluated as difference in area under the curve between i) a spatial G-function quantifying T cell density around tumor cells in tumor areas and ii) analogous null distributions obtained by random permutation of cell labels. This assessment of co-clustering is independent of cell density and heterogeneity therein and does not reflect repulsion of T cells to stromal/marginal areas. Clinical characteristics, RECIST response and survival were collected from patient records. Associations between T cell density, T cell proximity to Sox10/Melan-A+ tumor cells, other clinical biomarkers (LDH, M stage and WHO performance status) and response were examined in a Bayesian hierarchical logistic regression. Results: Tumor specimens of 98 patients were included, of whom 45 were treated with aPD1 as first-line therapy and 33 had an objective response. CD8 T cell proximity to tumor cells was associated with response in an independent, comparatively strong, and tissue dependent manner (cutaneous tissue: 2.78 [2.45, 3.17], visceral: 2.30 [1.95, 2.72], lymphoid: 2.12 [1.88, 2.40], format: maximal posteriori odds ratio [89% equal-tailed credibility interval]), in a multivariate model correcting for CD8 T cell density (1.74 [1.62, 1.88]), LDH (1.93 [1.72, 2.16]), M stage (0.92 [0.87, 0.98]) and WHO performance status (0.79 [0.72, 0.88]). Our model achieved an area under the ROC curve of 77.7%, whereas an analogous model omitting the proximity variable achieved 73.1%. Conclusions: Our analyses show that spatial proximity of CD8 T cells to tumor cells functions as an independent biomarker for response to aPD1 and suggests that preexisting CD8 T cell tumor reactivity is reflected by this spatial proximity.


Sign in / Sign up

Export Citation Format

Share Document