Manipulation of the breast-tumor microenvironment ex vivo to unleash TIL immunosuppression

Différentes nouvelles approches en immuno-thérapie sont admises dans la prise en charge moderne des cancers grâce aux avancées dans le domaine de l'immuno-oncologie. Le transfert adoptif de cellules T (ACT) est basé sur l'administration de lymphocytes infiltrant la tumeur (TILs), spécifiques du cancer et préalablement cultivés in vitro. Bien que les résultats soient très encourageants chez les patients atteints de mélanomes métastatiques, l'ACT n'est pas encore utilisé en clinique dans d'autres types de cancer. Dans le cancer du sein, l'infiltration des T CD8 est associée à un meilleur pronostic et encourage ainsi le développement d'une telle approche. Le microenvironnement tumoral joue un rôle majeur dans l'inhibition de l'activation et de l'expansion des TILs spécifiques du cancer du sein par de nombreux processus immunosuppresseurs. Différents types cellulaires interagissent en inhibant le développement d'une réponse anti-tumorale efficace, notamment les cellules myéloïdes suppressives (MDSCs). Dans cette étude, nous avons montré que les fonctions anti-tumorales des TILs du cancer du sein sont inhibées, et que ces TILs ne répondent pas aux stimuli de l'IL-2. Cependant nos résultats obtenus ex vivo montrent que la combinaison de l'IL-2 avec des inhibiteurs des récepteurs à tyrosine kinase (RTKI), ces derniers diminuant les activités angiogéniques et immunosuppressives des MDSCs dans le cancer du sein, permet la proliférations des TILs. Ces TILs présentent principalement un phénotype effecteur mémoire CD45RACCR7", sont spécifiques de la tumeur et capables de lyser les cellules tumorales autologues in vitro de façon spécifique. L'induction de l'expression de CD137 sur ces cellules a permis d'identifier une sous-population de TILs naturellement anti-tumorale, produisant des molecules effectrices (PerforinA, GranzymeB, IFN-y), et présentant une activité lytique supérieure in vitro. Nous avons également démontré que les RTKI ont un effet positif à la fois sur les cellules myéloïdes et les TILs au sein du micro-environnement tumoral. Ce traitement reprogramme les MDSCs en cellules dendritiques présentant une activité anti-tumorale, induit la diminution de l'expression de PD-L1 et diminue la sécrétion de la Prostaglandine E2 (PGE2). Les RTKI restaurent également l'assemblage du complexe IL-2R en diminuant les taux intracellulaires de l'AMP cyclique (cAMP) des TILs. De façon intéressante, nous avons observé que les taux de PGE2 in vitro ainsi que la co-expression de PD-1 avec d'autres récepteurs inhibiteurs sur les TILs déterminent les tumeurs répondant ou non à la combinaison IL-2 et RTKI. Nous suggérons ainsi que les axes PGE2/cAMP et PD-L1/PD-1 contribuent également à l'activité immunosuppressive des TILs du cancer du sein. Nous avons montré qu'en ciblant pharmacologiquement ces axes, nous induisons la reprogrammation des tumeurs non-répondeuses en répondeuses, ce qui résulte en une expansion accrue des TILs in vitro. Cette étude démontre pour la première fois, à notre connaissance, l'expansion de TILs fonctionnels spécifiques du cancer du sein. -- Tumor-infiltrating lymphocytes (TILs) show a wide diversity of cancer-antigen specificity, making them critical players in anti-tumor immunity. Their isolation and expansion in vitro using high doses of IL-2 followed by their autologous re-infusion have shown very encouraging results in metastatic melanoma patients. However, the adoptive cell transfer (ACT) of TILs remains poorly applicable in many cancer types due to defective TIL expansion. Breast cancer (BC) is the most common and second deadliest cancer in the western female population. Its infiltration with CD8+TILs has been associated with improved prognosis, thus encouraging the development of ACT approaches to treat BC patients. We hypothesized that the tumor microenvironment (TME) plays a major rôle in precluding the activation and the expansion of breast TILsthrough various immunosuppressive pathways includingthe activity of Tie- 2-expressing monocytes (TEM) that is driven by Tie-2 and VEGFR1 kinase activities. We showed that breast TILs are suppressed in their TME and are unresponsive to IL-2. However, we could overcome this suppression ex vivo by combining IL-2 and a combined blockade of Tie-2 and VEGFR1 using receptor tyrosine kinase inhibitors (RTKI), resulting in the successful expansion of TILs in thirty patient- derived breast tumors of différent histological subtypes and grades. Functionally, expanded TILs displayed mainly an effector memory phenotype, were tumor-specific and could kill autologous tumor cells in vitro in an MHC-dependent manner. Interestingly, CD137 upregulation in these settings identified a subset of naturally occurring tumor-reactive TILs. We further explored the mechanism of action of RTKI and showed that it affected both myeloid cells and TILs in the TME. RTKI induced myeloid cells repolarization towards anti-tumoral DC-like cells, induced the downregulation of their surface PD-L1 expression, and reduced their PGE2 sécrétion capabilities. Moreover, RTKI blocked VEGFRl/2-induced cAMP accumulation in TILs, thus restoringthe IL-2R complex assembly and subséquent responsiveness to IL-2. Interestingly, despite RTKI treatment, 40% of tumors remained weak-responders. We identified PGE2/cAMP and PD-1/PD-L1 axes as two immunosuppressive pathways highly activated in these tumors, which pharmacological targeting alongside RTKI and IL-2 reprogramed weak-responding TME into strong responders, resulting in the expansion of higher number of TILs in vitro. We are currently working on determining the molecular targets of RTKI in TILs. Future work consists on identifying and pharmacologically reversing the immunosuppressive eues specific to every breast TME, as well as on developing prédictive biomarkers so we could more appropriately correct TIL dysfunction and reprogram weak-responding tumors into strong-responders

Risk factors for Nontuberculous Mycobacteria Infections in Solid Organ Transplant recipients: a multinational case-control study

BACKGROUND: Risk factors for nontuberculous mycobacteria (NTM) infections after solid organ transplant (SOT) are not well characterized. Here we aimed to describe these factors. METHODS: Retrospective, multinational, 1:2 matched case-control study that included SOT recipients ≥12 years old diagnosed with NTM infection from January 1, 2008, to December 31, 2018. Controls were matched on transplanted organ, NTM treatment center, and post-transplant survival greater than or equal to the time to NTM diagnosis. Logistic regression on matched pairs was used to assess associations between risk factors and NTM infections. RESULTS: Analyses included 85 cases and 169 controls; (59% male, 88% white, median age at time of SOT of 54 years (IQR 40-62)). NTM infection occurred in kidney (42%), lung (35%), heart and liver (11% each), and pancreas transplant recipients (1%). Time from transplant to infection was 21.6 months (IQR 5.3-55.2). Most underlying comorbidities were evenly distributed between groups; however, cases were older at the time of NTM diagnosis, more frequently on systemic corticosteroids and had a lower lymphocyte count (all P < 0.05). In the multivariable model, older age at transplant (adjusted odds ratio [aOR] 1.04; 95 confidence interval [CI] 1.01-1.07), hospital admission within 90 days (aOR, 3.14; [1.41-6.98]), receipt of antifungals (aOR, 5.35; [1.7-16.91]), and lymphocyte-specific antibodies (aOR, 7.73, [1.07-56.14]), were associated with NTM infection. CONCLUSION: Risk of NTM infection in SOT recipients was associated with older age at SOT, prior hospital admission, receipt of antifungals or lymphocyte-specific antibodies. NTM infection should be considered in SOT patients with these risk factors

Risk Factors for Nontuberculous Mycobacteria Infections in Solid Organ Transplant Recipients: A Multinational Case-Control Study

Background Risk factors for nontuberculous mycobacteria (NTM) infections after solid organ transplant (SOT) are not well characterized. Here we aimed to describe these factors. Methods Retrospective, multinational, 1:2 matched case-control study that included SOT recipients >= 12 years old diagnosed with NTM infection from 1 January 2008 to 31 December 2018. Controls were matched on transplanted organ, NTM treatment center, and post-transplant survival greater than or equal to the time to NTM diagnosis. Logistic regression on matched pairs was used to assess associations between risk factors and NTM infections. Results Analyses included 85 cases and 169 controls (59% male, 88% White, median age at time of SOT of 54 years [interquartile range {IQR} 40-62]). NTM infection occurred in kidney (42%), lung (35%), heart and liver (11% each), and pancreas transplant recipients (1%). Median time from transplant to infection was 21.6 months (IQR 5.3-55.2). Most underlying comorbidities were evenly distributed between groups; however, cases were older at the time of NTM diagnosis, more frequently on systemic corticosteroids and had a lower lymphocyte count (all P < .05). In the multivariable model, older age at transplant (adjusted odds ratio [aOR] 1.04; 95 confidence interval [CI], 1.01-1.07), hospital admission within 90 days (aOR, 3.14; 95% CI, 1.41-6.98), receipt of antifungals (aOR, 5.35; 95% CI, 1.7-16.91), and lymphocyte-specific antibodies (aOR, 7.73; 95% CI, 1.07-56.14), were associated with NTM infection. Conclusions Risk of NTM infection in SOT recipients was associated with older age at SOT, prior hospital admission, receipt of antifungals or lymphocyte-specific antibodies. NTM infection should be considered in SOT patients with these risk factors. In this multinational, 1:2 matched case-control study of solid organ transplant (SOT) recipients, older age at transplantation; and hospital admission, receipt of antifungals or lymphocyte-specific antibodies within 90 days of nontuberculous mycobacteria (NTM) disease were associated with increased odds of disease in the multivariable model