Immunoregulatory effects of Lurbinectedin in chronic lymphocytic leukemia.

Despite significant therapeutic improvements chronic lymphocytic leukemia (CLL) remains an incurable disease and there is a persistent pursuit of new treatment alternatives. Lurbinectedin, a selective inhibitor of active transcription of protein-coding genes, is currently in phase II/III clinical trials for solid tumors such as small-cell lung cancer (SCLC). In this study, we aimed to evaluate the activity of Lurbinectedin on circulating mononuclear cells from CLL patients and to determine whether Lurbinectedin could affect the cross-talk between B-CLL cells and the tumor microenvironment. We found that Lurbinectedin induced a dose- and time-dependent death in all cell types evaluated, with B cells, monocytes and monocytic myeloid derived suppressor cells (Mo-MDSC) being the most susceptible populations. At sub-apoptotic doses, Lurbinectedin decreased the expression of CCR7 in B-CLL cells and impaired their migration towards CCL19 and CCL21. Furthermore, low concentrations of Lurbinectedin stimulated the synthesis of pro-IL1ß in monocytes and nurse-like cells, without inducing the inflammasome activation. Altogether, these results indicate that Lurbinectedin might have antitumor activity in CLL due to its direct action on leukemic cells in combination with its effects on the tumor microenvironment. Our findings encourage further investigation of Lurbinectedin as a potential therapy for CLL.

Distinctive role of efferocytosis in dendritic cell maturation and migration in sterile or infectious conditions.

Efferocytosis, or clearance of apoptotic cells (ACs), by dendritic cells (DCs) leads to immune response suppression and tolerance to self-antigens. However, efferocytosis of infected apoptotic cells (IACs) leads to the production of a mixed pro- and anti-inflammatory cytokine milieu. We examined the DC phenotype and ability to migrate after phagocytosis of ACs or IACs and observed higher levels of CD86 and CCR7 expression in DCs, as well as enhanced migration capacity following efferocytosis of IACs. Interestingly, higher levels of interleukin-1ß, interleukin-10 and prostaglandin E2 (PGE2 ) were also produced in this context. Blockage of IAC recognition led to an impaired maturation profile and PGE2 production, which may have contributed to reduced CD86 and CCR7 expression and migration capacity. These data contribute to the understanding of how efferocytosis of sterile or infected cells may regulate the adaptive immune response, although the precise role of PGE2 in this process requires further investigation.

Human breast cancer-derived soluble factors facilitate CCL19-induced chemotaxis of human dendritic cells.

Breast cancer remains as a challenging disease with high mortality in women. Increasing evidence points the importance of understanding a crosstalk between breast cancers and immune cells, but little is known about the effect of breast cancer-derived factors on the migratory properties of dendritic cells (DCs) and their consequent capability in inducing T cell immune responses. Utilizing a unique 3D microfluidic device, we here showed that breast cancers (MCF-7, MDA-MB-231, MDA-MB-436 and SK-BR-3)-derived soluble factors increase the migration of DCs toward CCL19. The enhanced migration of DCs was mainly mediated via the highly activated JNK/c-Jun signaling pathway, increasing their directional persistence, while the velocity of DCs was not influenced, particularly when they were co-cultured with triple negative breast cancer cells (TNBCs or MDA-MB-231 and MDA-MB-436). The DCs up-regulated inflammatory cytokines IL-1ß and IL-6 and induced T cells more proliferative and resistant against activation-induced cell death (AICD), which secret high levels of inflammatory cytokines IL-1ß, IL-6 and IFN-γ. This study demonstrated new possible evasion strategy of TNBCs utilizing their soluble factors that exploit the directionality of DCs toward chemokine responses, leading to the building of inflammatory milieu which may support their own growth.

Renin-angiotensin system contributes to naive T-cell migration in vivo.

Angiotensin II (Ang II) plays an important role in the regulation of the T-cell response during inflammation. However, the cellular mechanisms underlying the regulation of lymphocytes under physiologic conditions have not yet been studied. Here, we tested the influence of Ang II on T-cell migration using T cells from BALB/c mice. The results obtained in vivo showed that when Ang II production or the AT1 receptor were blocked, T-cell counts were enhanced in blood but decreased in the spleen. The significance of these effects was confirmed by observing that these cells migrate, through fibronectin to Ang II via the AT1 receptor. We also observed a gradient of Ang II from peripheral blood to the spleen, which explains its chemotactic effect on this organ. The following cellular mechanisms were identified to mediate the Ang II effect: upregulation of the chemokine receptor CCR9; upregulation of the adhesion molecule CD62L; increased production of the chemokines CCL19 and CCL25 in the spleen. These results indicate that the higher levels of Ang II in the spleen and AT1 receptor activation contribute to migration of naive T cells to the spleen, which expands our understanding on how the Ang II/AT1 receptor axis contributes to adaptive immunity.

The expression of chemokines CCL19, CCL21 and their receptor CCR7 in oral squamous cell carcinoma and its relevance to cervical lymph node metastasis.

The purpose of this study is to determine the expression of CCL19, CCL21, and CCR7 in samples of oral squamous cell carcinoma (OSCC) and their relationship with clinical and microscopic parameters. A comparative analysis was made of the mRNA expression of these chemokines and receptor in OSCC and normal oral mucosa. The immunoexpression of CCR7, CCL19, and CCL21 was also verified in OSCC and lymph nodes. Statistical significance was accepted at P < 0.05. Similar levels of CCR7, CCL19, and CCL21 mRNA in OSCC and normal oral mucosa were seen. A low expression of CCL19 and CCL21 in the intra- and peritumoral regions was observed. Scarce CCL19(+) and CCL21(+) cells were also noted in metastatic and non-metastatic lymph nodes. No association was found between the expression of these chemokines and clinical and microscopic parameters. Our findings would suggest that CCL19 and CCL21 may not be associated with cervical lymph node metastasis or other clinical and microscopic factors in OSCC.

Maturation of human iDCs by IL-18 plus PGE2, but not by each stimulus alone, induced migration toward CCL21 and the secretion of IL-12 and IFN-γ.

Dendritic cells (DCs) are potent antigen-presenting cells that initiate the primary immune response and whose functional properties in vivo depend on the maturation stimulus. We describe the functional properties of human monocyte-derived DCs after the maturation of immature DCs (iDCs) for 2 days with LPS (100 ng/ml), PGE2 (1 µg/ml), CD40L (1 µg/ml) or IL-18 (200 ng/ml) and with CD40L+PGE2 and IL-18+PGE2 mixtures at the same concentrations as above. Neither IL-18 nor PGE2 alone stimulated IL-12 or IFN-γ secretion. When administered simultaneously to 1×10(6)iDCs/ml, IL-18+PGE2 induced the secretion of 131.4±6.7 pg IL-12/ml and 355±87 pg IFN-γ/ml but there was no detectable IL-10 secretion. However, PGE2 alone stimulated the secretion of 208±89 pg IL-10/ml whereas IL-18 alone did not stimulate the secretion of IL-10, IL-12, TNF-α or INF-γ. When the mixture of CD40L+PGE2 was used, only migration toward CCL19 and CCL21 was induced. CD40L did not stimulate the secretion of IL-10, IL-12, TNF-α or IFN-γ and did not stimulate migration toward CCL19 or CCL21. The extent of stimulation of T cell proliferation was essentially the same for all stimuli at the concentrations given above. New properties such as IL-12 and INF-γ secretion and migration toward CCL21 emerged when a mixture of IL-18+PGE2 was employed. These data show that when the pairs of stimuli reported here were used simultaneously their effect was not additive. This system can be used to prepare mDCs with properties useful for cell therapy and also as a model to investigate the mechanisms of cytokine secretion and cell migration.