Publications by authors named "Samantha Knockaert"

Tertiary lymphoid structures (TLS) are de novo lymphoid formations that are induced within tissues during inflammatory episodes. TLS have been reported at various anatomic sites and in many different contexts like cancer, infections, autoimmunity, graft rejection, and idiopathic diseases. These inducible, ectopic, and transient lymphoid structures exhibit the prototypical architecture found within secondary lymphoid organs (SLO) and have been increasingly recognized as a major driver of local adaptive immune reaction.

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The success of cancer immunotherapies such as immune checkpoint inhibitors, CAR T-cells and immune cell engagers have provided clinicians with tools to bypass some of the limitations of cancer immunity. However, numerous tumour factors curtail the immune response against cancer and limit the efficiency of immuno-oncology (IO) therapies. Acidification of the extra-cellular tumour environment consecutive to aberrant cancer cell metabolism is a well-known promoter of oncogenic processes that also acts as an immune regulator.

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On one hand, regulatory T cells (Tregs) play an immunosuppressive activity in most solid tumors but not all. On the other hand, the organization of tumor-infiltrating immune cells into tertiary lymphoid structures (TLS) is associated with long-term survival in most cancers. Here, we investigated the role of Tregs in the context of Non-Small Cell Lung Cancer (NSCLC)-associated TLS.

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Article Synopsis
  • * This study analyzed 56 NSCLC patients and found that high densities of TLS-B cells correlated with better profiles of CD4 T cells, showing more naïve and activated types while reducing regulatory T cells (Tregs) and immune checkpoints.
  • * A larger study involving 538 untreated NSCLC patients indicated that high TLS-B cell density could mitigate negative impacts from high Treg levels, with patients exhibiting both high TLS-B and Treg densities showing the best survival rates, highlighting B cells' crucial role in immune protection.
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Intravascular hemolysis of any cause can induce acute kidney injury (AKI). Hemolysis-derived product heme activates the innate immune complement system and contributes to renal damage. Therefore, we explored the role of the master complement regulator Factor H (FH) in the kidney's resistance to hemolysis-mediated AKI.

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Tertiary lymphoid structures (TLS) are de novo lymphoid formations that are induced within tissues during inflammatory episodes. TLS have been reported at various anatomic sites and in many different contexts like cancer, infections, autoimmunity, graft rejection, and idiopathic diseases. These inducible, ectopic, and transient lymphoid structures exhibit the prototypical architecture found within secondary lymphoid organs (SLO) and have been recently appreciated as a major driver of the local adaptive immune reaction.

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In hemolytic diseases, such as sickle cell disease (SCD), intravascular hemolysis results in the release of hemoglobin, heme, and heme-loaded membrane microvesicles in the bloodstream. Intravascular hemolysis is thus associated with inflammation and organ injury. Complement system can be activated by heme in vitro.

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Co-stimulatory and inhibitory receptors expressed by immune cells in the tumor microenvironment modulate the immune response and cancer progression. Their expression and regulation are still not fully characterized and a better understanding of these mechanisms is needed to improve current immunotherapies. Our previous work has identified a novel ligand/receptor pair, LLT1/CD161, that modulates immune responses.

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Intravascular erythrocyte destruction, accompanied by the release of pro-oxidative and pro-inflammatory components hemoglobin and heme, is a common event in the pathogenesis of numerous diseases with heterogeneous etiology and clinical features. A frequent adverse effect related to massive hemolysis is the renal injury and inflammation. Nevertheless, it is still unclear whether heme--a danger-associated molecular pattern--and ligand for TLR4 or upstream hemolysis-derived products are responsible for these effects.

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T and B cell receptor (TCR and BCR, respectively) Vβ or immunoglobulin heavy chain complementarity-determining region 3 sequencing allows monitoring of repertoire changes through recognition, clonal expansion, affinity maturation, and T or B cell activation in response to antigen. TCR and BCR repertoire analysis can advance understanding of antitumor immune responses in the tumor microenvironment. TCR and BCR repertoires of sorted CD4, CD8 or CD19 cells in tumor, non-tumoral distant tissue (NT), and peripheral compartments (blood/draining lymph node [P]) from 47 non-small cell lung cancer (NSCLC) patients (age = 68 y) were sequenced.

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Rationale: It is now well established that immune responses can take place outside of primary and secondary lymphoid organs. We previously described the presence of tertiary lymphoid structures (TLS) in patients with non-small cell lung cancer (NSCLC) characterized by clusters of mature dendritic cells (DCs) and T cells surrounded by B-cell follicles. We demonstrated that the density of these mature DCs was associated with favorable clinical outcome.

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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).

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