Luc de Chaisemartin

Long-Term Survival for Patients With Non–Small-Cell Lung Cancer With Intratumoral Lymphoid Structures

PURPOSE It has been established that the immune system plays an important role in tumor rejection. There is also compelling evidence that immune responses can develop independently of secondary lymphoid organs in tertiary lymphoid structures. We studied the presence and the correlation of tertiary lymphoid structures with clinical outcome in non-small-cell lung cancer (NSCLC), as the prognostic value of these structures in patients with cancer had not yet been established. PATIENTS AND METHODS This retrospective study was performed by immunohistochemistry on paraffin-embedded tissue specimens from 74 patients with early-stage NSCLC. RESULTS Tertiary lymphoid structures were detected in some tumors but not in nontumoral lungs. Thus we called these structures tumor-induced bronchus-associated lymphoid tissue (Ti-BALT). As in lymph nodes, Ti-BALTs were composed of mature dendritic cell (DC)/T-cell clusters adjacent to B-cell follicles and had features of an ongoing immune response. Because the quantitative counting of Ti-BALT was difficult to achieve, we used mature DCs that homed exclusively in Ti-BALT as a specific marker of these structures. Univariate analysis showed that the density of mature DCs was highly associated with a favorable clinical outcome (overall, disease-specific, and disease-free survival), suggesting that Ti-BALT may participate in antitumoral immunity. The density of tumor-infiltrating lymphocytes, in particular, CD4(+) and T-bet(+) Th1 T cells, was profoundly decreased in tumors weakly infiltrated by mature DCs. CONCLUSION The density of mature DCs was found to be a better predictor of clinical outcome than the other parameters tested. The number of tumor-infiltrating mature DCs may identify patients with early-stage NSCLC who have a high risk of relapse.

Dendritic Cells in Tumor-Associated Tertiary Lymphoid Structures Signal a Th1 Cytotoxic Immune Contexture and License the Positive Prognostic Value of Infiltrating CD8+ T Cells

Tumor-infiltrating T cells, particularly CD45RO(+)CD8(+) memory T cells, confer a positive prognostic value in human cancers. However, the mechanisms that promote a protective T-cell response in the tumor microenvironment remain unclear. In chronic inflammatory settings such as the tumor microenvironment, lymphoid neogenesis can occur to create local lymph node-like structures known as tertiary lymphoid structures (TLS). These structures can exacerbate a local immune response, such that TLS formation in tumors may help promote an efficacious immune contexture. However, the role of TLS in tumors has yet to be investigated carefully. In lung tumors, mature dendritic cells (DC) present in tumor-associated TLS can provide a specific marker of these structures. In this study, we evaluated the influence of TLS on the characteristics of the immune infiltrate in cohorts of prospective and retrospective human primary lung tumors (n = 458). We found that a high density of mature DC correlated closely to a strong infiltration of T cells that are predominantly of the effector-memory phenotype. Moreover, mature DC density correlated with expression of genes related to T-cell activation, T-helper 1 (Th1) phenotype, and cytotoxic orientation. Lastly, a high density of TLS-associated DC correlated with long-term survival, which also allowed a distinction of patients with high CD8(+) T-cell infiltration but a high risk of death. Taken together, our results show how tumors infiltrated by TLS-associated mature DC generate a specific immune contexture characterized by a strong Th1 and cytotoxic orientation that confers the lowest risk of death. Furthermore, our findings highlight the pivotal function of TLS in shaping the immune character of the tumor microenvironment, in promoting a protective immune response mediated by T cells against cancer.

Application of Deamidated Gliadin Antibodies in the Follow-Up of Treated Celiac Disease

Introduction The role of serological tests such as IgA anti-transglutaminase autoantibodies has become increasingly important in celiac disease (CD) diagnosis. However, the efficiency of these tests for patient follow-up is controversial. We investigated the correlation of 12 different serological tests, including recent deamidated gliadin and actin IgA tests, with villous atrophy (VA) in a retrospective cohort of treated celiac patients. Materials and Methods Serum samples were collected from 100 treated CD patients who had intestinal biopsy in the course of their follow-up. Antibodies against transglutaminase, deamidated gliadin peptides, and native gliadin were measured, along with IgA anti-actin. The biopsy slides were all blind-reviewed and scored according to Marsh classification. Results For all deamidated gliadin and transglutaminase tests, we found that a positive result was significantly associated with persistence of intestinal VA, with a diagnostic efficacy up to 80%. Furthermore, antibodies titers directly correlated with the degree of VA, indicating a strong link between disease activity and presence of antibodies in the serum. Interestingly, the tests with the highest association with persistent VA were those for deamidated gliadin IgG. Using a test positivity pattern analysis, we were also able to identify several groups of patients with distinct antibody profiles that showed significant differences in intestinal damage and diet compliance. Conclusions Altogether, these results show that deamidated gliadin antibodies are strongly correlated with VA and should be considered valuable tools in CD follow-up and that multiplex serologic analysis for treated CD represents a promising tool for personalized patient management.

Human blood monocytes are able to form extracellular traps

Neutrophil extracellular traps (NETs) are extracellular DNA filaments formed during neutrophil activation. This process, called netosis, was originally associated with neutrophil antibacterial properties. However, several lines of evidence now suggest a major role for netosis in thrombosis, autoimmune diseases, and cancer. We demonstrate here that highly purified human blood monocytes are also capable of extracellular trap (ET) release in response to several stimuli. Monocyte ETs display a morphology analogous to NETs and are associated with myeloperoxidase (MPO), lactoferrin (LF), citrullinated histones, and elastase. Monocyte ET release depends on oxidative burst but not on MPO activity, in contrast to neutrophils. Moreover, we demonstrate procoagulant activity for monocyte ETs, a feature that could be relevant to monocyte thrombogenic properties. This new cellular mechanism is likely to have implications in the multiple pathologic contexts where monocytes are implicated, such as inflammatory disorders, infection, or thrombosis.

When neutrophils cast their nets.

Joint Bone Spine - In Press.Proof corrected by the author Available online since vendredi 1 mars 2013

Comparison of Basophil Activation Test and Skin Testing Performances in NMBA Allergy

BACKGROUND Neuromuscular blocking agents (NMBAs) are the main agents involved during perioperative immediate hypersensitivity. The etiological diagnosis (IgE-mediated allergy vs nonallergy) is linked to the clinical presentation together with tryptase and histamine levels and skin test results. The role of basophil activation test (BAT) needs to be better defined in this setting. OBJECTIVES To assess the role of BAT compared with the results of skin testing in 31 patients experiencing immediate NMBA hypersensitivity and compare skin test results and BAT performances in the identification of alternative NMBAs. METHODS Histamine and tryptase levels were quantified. Anesthetic drugs, including NMBAs, were skin-tested. Basophil CD63 and CD203c expressions were measured in response to serial dilutions of the different NMBAs. RESULTS Allergy and Nonallergy groups involved 19 and 12 patients, respectively. Circulating histamine and tryptase levels were significantly increased in allergic patients. In the Allergy group, while skin test results were positive in 100% (19 of 19) of the cases, BAT positivity to the culprit NMBA reached 78.9% (15 of 19) when combining CD63 and CD203c. NMBAs cross-reactivity was identified through skin testing and BAT in 36.8% (7 of 19) and 26.3% (5 of 19) of the cases, respectively. The concordance (culprit and cross-reactive NMBAs) between skin tests and BATs was between 73.6% (14 of 19) and 100% (19 of 19) for each NMBA. Negative skin-tested NMBAs were uneventfully used in 7 NMBA-allergic patients. In the Nonallergy group, skin test results were negative in 100% of the cases while BAT result was positive once (CD63 upregulation). CONCLUSION In our technical conditions, BAT does not replace skin testing in the assessment of NMBA allergy.

Abstract LB-498: Density of tertiary lymphoid structures is associated with activated and effector-memory T lymphocyte infiltration in human lung tumor

Proceedings: AACR 103rd Annual Meeting 2012‐‐ Mar 31‐Apr 4, 2012; Chicago, IL Introduction: An increasing number of studies have demonstrated a strong correlation between T cell infiltrate and clinical outcome in several types of human solid cancers. Nevertheless, the mechanisms governing T-cell infiltration and activation into tumors remain poorly characterized. In lung cancer, our team has observed the presence of tertiary lymphoid structures called Ti-BALT (Tumor-induced Bronchus-Associated Lymphoid Tissues). These structures present features of an ongoing immune response and their density is associated with long-term survival for lung cancer patients, suggesting their implication in local T cell recruitment and activation. We recently published a specific gene expression signature associated with T cell presence in Ti-BALT, which includes lymphoid chemokines, adhesion molecules, and integrins (De Chaisemartin L, et al. Cancer Research 2011). This chemoattractant gene expression signature strongly suggests an active recruitment of immune cells in these structures. Our aim was to study the influence of these structures on the composition, density and functionality of the immune infiltrate in lung tumors. Methods: The expression of relevant molecules was assessed on fresh tumor-infiltrating lymphocytes by multicolor flow cytometry, on tissue sections by immunohistochemistry and on frozen tumors by Low Density Array analysis. Results: Large-scale flow cytometry analysis revealed an increased infiltration of T and B but not NK cells in tumors with a high density of Ti-BALT as compared to tumors with a low density. A significant increase proportion of activated and effector-memory T cell subsets was observed in Ti-BALT high versus low tumors. Whereas most T cells located in Ti-BALT had a naive and early memory T cell phenotype, as observed in canonical secondary lymphoid organs, T cells located outside Ti-BALT were significantly enriched in effector-memory T cell phenotype. Finally, Ki-67+ proliferating T cells were found in close contact with mature dendritic cells in Ti-BALT, suggesting a local priming of T cells in these structures. Conclusion: Together, these data suggest that Ti-BALT represent a privileged area for T cell recruitment and activation in the primary site of the tumor. This mechanism could lead to the establishment and maintenance of a protective anti-tumor immune response directly in the tumor. These findings give news insights about mechanisms of T cell infiltration and activation in tumor microenvironment, suggesting new strategies to enhance the efficacy of cancer immunotherapies. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-498. doi:1538-7445.AM2012-LB-498