Focal adhesion kinase inhibition decreases cell viability and induces apoptosis of JAK2 V617F positive cells

Abstract Focal Adhesion Kinase (FAK) protein participates in proliferation, migration, cell survival, and apoptosis process. It has been described as overexpressed in several neoplasms being a promising target for therapy. BCR-ABL negative chronic Myeloproliferative Neoplasms (MPN) are clonal disorders characterized by the excess of proliferation and apoptosis resistance. The identification of the acquired JAK2 V617F mutation in MPN patients allowed a better understanding of pathogenesis. However, there is still no pharmacological treatment that leads all patients to molecular remission, justifying new studies. The present study aimed to evaluate FAK involvement in the viability and apoptosis of HEL and SET-2 cells, both JAK2 V617F positive cell lines. The FAK inhibitor PF 562,271 was used. Cell viability was determined using MTT assay and apoptosis verified by cleaved PARP, cleaved Caspase 3 and Annexin-V/PI staining detection. FAK inhibition significantly reduced HEL and SET-2 cells viability and induced apoptosis. Considering the role of JAK/STAT pathway in MPN, further investigation of FAK participation in the MPN cells proliferation and apoptosis resistance, as well as possible crosstalk between JAK and FAK and downstream pathways may contribute to the knowledge of MPN pathophysiology, the discovery of new molecular targets, and JAK inhibitors resistance mechanisms.

Tumor necrosis factor α, and agonist and antagonists of cannabinoid receptor type 1 and type 2 alter the immunophenotype of stem cells from human exfoliated deciduous teeth

ABSTRACT Objective To verify the involvement of the endocannabinoid system in the immunomodulatory profile of stem cells from human exfoliated deciduous teeth, in the presence or absence of TNF-α, and agonist and antagonists of CB1 and CB2. Methods Stem cells from human exfoliated deciduous teeth were cultured in the presence or absence of an agonist, anandamide, and two antagonists, AM251 and SR144528, of CB1 and CB2 receptors, with or without TNF-α stimulation. For analysis of immunomodulation, surface molecules linked to immunomodulation, namely human leukocyte antigen-DR isotype (HLA-DR), and programmed death ligands 1 (PD-L1) and 2 (PD-L2) were measured using flow cytometry. Results The inhibition of endocannabinoid receptors together with the proinflammatory effect of TNF-α resulted in increased HLA-DR expression in stem cells from human exfoliated deciduous teeth, as well as, in these cells acquiring an anti-inflammatory profile by enhancing the expression of PD-L1 and PD-L2. Conclusion Stem cells from human exfoliated deciduous teeth respond to the endocannabinoid system and TNF-α by altering key immune response molecules.

Infecções helmínticas crônicas aumentam a susceptibilidade ao Mycobacterium tuberculosis e reduzem a eficácia da vacina BCG / Chronic helminths infections increases susceptibility to Mycobacterium tuberculosis and diminishes BCG vaccination effectiveness

A eficácia do Bacilo Calmette Guerin (BCG) é baixa e a incidência de tuberculose é elevada em áreas onde os helmintos são endêmicos. Enquanto a proteção contra a tuberculose exige forte imunidade celular, infecções helmínticas crônicas induzem respostas caracterizadas pelo perfil Th2, bem como o aumento da atividade de células T reguladoras. Portanto, infecções helmínticas crônicas poderiam modular a resposta imunológica necessária para controlar a infecção por micobactérias e/ou a eficácia da vacinação com BCG.

The effectiveness of Bacille Calmette Guerin (BCG) is low and the incidence of tuberculosis is high in areas where helminths are endemic. While protection against tuberculosis requires strong cellular immunity, chronic helminth infections induce responses characterized by Th2 profile, as well as increased T regulatory cell activity. Therefore, chronic helminth infection could modulate the immune response needed to control mycobacterial infection and/or the efficacy of vaccination against tuberculosis

Anti-mycobacterial treatment reduces high plasma levels of CXC-chemokines detected in active tuberculosis by cytometric bead array

Chemokines recruit and activate leukocytes, assisting granuloma formation. Herein, we evaluated plasma chemokines in patients with active tuberculosis (ATB) and after completing treatment (TTB) and compared them to BCG-vaccinated healthy controls (HC). Levels of chemokines were measured by cytometric bead array. Levels of CXCL8, CXCL9 and CXCL10 were higher in ATB patients compared to HC, but they decreased in TTB. Levels of CCL2 and CCL5 in ATB patients were similar to those observed in HC. Thus, the high levels of CXC-chemokines detected during ATB, which can modulate the trafficking of immune cells from the periphery to the site of infection, were reversed by anti-mycobacterial treatment.