Severe COVID-19 Shares a Common Neutrophil Activation Signature with Other Acute Inflammatory States.

Severe COVID-19 patients present a clinical and laboratory overlap with other hyperinflammatory conditions such as hemophagocytic lymphohistiocytosis (HLH). However, the underlying mechanisms of these conditions remain to be explored. Here, we investigated the transcriptome of 1596 individuals, including patients with COVID-19 in comparison to healthy controls, other acute inflammatory states (HLH, multisystem inflammatory syndrome in children [MIS-C], Kawasaki disease [KD]), and different respiratory infections (seasonal coronavirus, influenza, bacterial pneumonia). We observed that COVID-19 and HLH share immunological pathways (cytokine/chemokine signaling and neutrophil-mediated immune responses), including gene signatures that stratify COVID-19 patients admitted to the intensive care unit (ICU) and COVID-19_nonICU patients. Of note, among the common differentially expressed genes (DEG), there is a cluster of neutrophil-associated genes that reflects a generalized hyperinflammatory state since it is also dysregulated in patients with KD and bacterial pneumonia. These genes are dysregulated at the protein level across several COVID-19 studies and form an interconnected network with differentially expressed plasma proteins that point to neutrophil hyperactivation in COVID-19 patients admitted to the intensive care unit. scRNAseq analysis indicated that these genes are specifically upregulated across different leukocyte populations, including lymphocyte subsets and immature neutrophils. Artificial intelligence modeling confirmed the strong association of these genes with COVID-19 severity. Thus, our work indicates putative therapeutic pathways for intervention.

The War Is on: The Immune System against Glioblastoma-How Can NK Cells Drive This Battle?

Natural killer (NK) cells are innate lymphocytes that play an important role in immunosurveillance, acting alongside other immune cells in the response against various types of malignant tumors and the prevention of metastasis. Since their discovery in the 1970s, they have been thoroughly studied for their capacity to kill neoplastic cells without the need for previous sensitization, executing rapid and robust cytotoxic activity, but also helper functions. In agreement with this, NK cells are being exploited in many ways to treat cancer. The broad arsenal of NK-based therapies includes adoptive transfer of in vitro expanded and activated cells, genetically engineered cells to contain chimeric antigen receptors (CAR-NKs), in vivo stimulation of NK cells (by cytokine therapy, checkpoint blockade therapies, etc.), and tumor-specific antibody-guided NK cells, among others. In this article, we review pivotal aspects of NK cells' biology and their contribution to immune responses against tumors, as well as providing a wide perspective on the many antineoplastic strategies using NK cells. Finally, we also discuss those approaches that have the potential to control glioblastoma-a disease that, currently, causes inevitable death, usually in a short time after diagnosis.

Could Increased Expression of Hsp27, an "Anti-Inflammatory" Chaperone, Contribute to the Monocyte-Derived Dendritic Cell Bias towards Tolerance Induction in Breast Cancer Patients?

Dendritic cells (DCs) are the most efficient antigen-presenting cells and link the innate immune sensing of the environment to the initiation of adaptive immune responses, which may be directed to either acceptance or elimination of the recognized antigen. In cancer patients, though DCs would be expected to present tumor antigens to T lymphocytes and induce tumor-eliminating responses, this is frequently not the case. The complex tumor microenvironment subverts the immune response, blocks some effector mechanisms, and drives others to support tumor growth. Chronic inflammation in a tumor microenvironment is believed to contribute to the induction of such regulatory/tolerogenic response. Among the various mediators of the modulatory switch in chronic inflammation is the "antidanger signal" chaperone, heat shock protein 27 (Hsp27), that has been described, interestingly, to be associated with cell migration and drug resistance of breast cancer cells. Thus, here, we investigated the expression of Hsp27 during the differentiation of monocyte-derived DCs (Mo-DCs) from healthy donors and breast cancer patients and evaluated their surface phenotype, cytokine secretion pattern, and lymphostimulatory activity. Surface phenotype and lymphocyte proliferation were evaluated by flow cytometry, interferon- (IFN-) γ, and interleukin- (IL-) 10 secretion, by ELISA and Hsp27 expression, by quantitative polymerase chain reaction (qPCR). Mo-DCs from cancer patients presented decreased expression of DC maturation markers, decreased ability to induce allogeneic lymphocyte proliferation, and increased IL-10 secretion. In coculture with breast cancer cell lines, healthy donors' Mo-DCs showed phenotype changes similar to those found in patients' cells. Interestingly, patients' monocytes expressed less GM-CSF and IL-4 receptors than healthy donors' monocytes and Hsp27 expression was significantly higher in patients' Mo-DCs (and in tumor samples). Both phenomena could contribute to the phenotypic bias of breast cancer patients' Mo-DCs and might prove potential targets for the development of new immunotherapeutic approaches for breast cancer.

Frequency determination of breast tumor-reactive CD4 and CD8 T cells in humans: unveiling the antitumor immune response.

As cancer immunotherapy gains importance, the determination of a patient's ability to react to his/her tumor is unquestionably relevant. Though the presence of T cells that recognize specific tumor antigens is well established, the total frequency of tumor-reactive T cells in humans is difficult to assess, especially due to the lack of broad analysis techniques. Here, we describe a strategy that allows this determination, in both CD4 and CD8 compartments, using T cell proliferation induced by tumor cell-lysate pulsed dendritic cells as the readout. All 12 healthy donor tested had circulating CD4 and CD8 tumor cell-reactive T cells. The detection of these T cells, not only in the naïve but also in the memory compartment, can be seen as an evidence of tumor immunosurveillance in humans. As expected, breast cancer patients had higher frequencies of blood tumor-reactive T cells, but with differences among breast cancer subtypes. Interestingly, the frequency of blood tumor-reactive T cells in patients did not correlate to the frequency of infiltrating tumor-reactive T cells, highlighting the danger of implying a local tumor response from blood obtained data. In conclusion, these data add T cell evidence to immunosurveillance in humans, confirm that immune parameters in blood may be misleading and describe a tool to follow the tumor-specific immune response in patients and, thus, to design better immunotherapeutic approaches.

Local and systemic immunomodulatory mechanisms triggered by Human Papillomavirus transformed cells: a potential role for G-CSF and neutrophils.

Cervical cancer is the last stage of a series of molecular and cellular alterations initiated with Human Papillomavirus (HPV) infection. The process involves immune responses and evasion mechanisms, which culminates with tolerance toward tumor antigens. Our objective was to understand local and systemic changes in the interactions between HPV associated cervical lesions and the immune system as lesions progress to cancer. Locally, we observed higher cervical leukocyte infiltrate, reflected by the increase in the frequency of T lymphocytes, neutrophils and M2 macrophages, in cancer patients. We observed a strong negative correlation between the frequency of neutrophils and T cells in precursor and cancer samples, but not cervicitis. In 3D tumor cell cultures, neutrophils inhibited T cell activity, displayed longer viability and longer CD16 expression half-life than neat neutrophil cultures. Systemically, we observed higher plasma G-CSF concentration, higher frequency of immature low density neutrophils, and tolerogenic monocyte derived dendritic cells, MoDCs, also in cancer patients. Interestingly, there was a negative correlation between T cell activation by MoDCs and G-CSF concentration in the plasma. Our results indicate that neutrophils and G-CSF may be part of the immune escape mechanisms triggered by cervical cancer cells, locally and systemically, respectively.

Cationic liposomes produced via ethanol injection method for dendritic cell therapy.

Cationic liposomes can be designed and developed in order to be an efficient gene delivery system for mammalian cells. Dendritic cell (DC) vaccines can be used to treat cancer, as cationic liposomes can deliver tumor antigens to cells while cells remain active. However, most methods used for liposome production are not able to reproduce in large scale the physicochemical and biological properties of liposomes produced in laboratory scale. In this context, ethanol injection method achieved promising results, although requiring post-treatment for size reduction and/or to remove residual ethanol. Thus, the purpose of this study was to generate cationic liposomes suitable for gene therapies via ethanol injection method in only one step (VEI) and compared to those submitted to a size reduction processes by microfluidization (MFV). For this, the method to produce cationic liposomes composed of egg phosphatidylcholine (EPC), 1,2-dioleoyl-3-trimethylammonium propane (DOTAP) and 1,2-dioleoylphosphatidylethanolamine (DOPE) was optimized using a statistical design approach. As a result, the size of VEI decreased from 290 nm to 110 nm and the polydispersity from 0.54 to 0.17. In the case of MFV, size decreased from 128 nm to 107 nm and polydispersity from 0.40 to 0.18. ST and MFV before and after optimization were also characterized in terms of morphology by transmission electron microscopy (TEM) and structure by differential scanning calorimetry (DSC). Finally, to show their potential in gene/immune therapies applications, DCs were stimulated by such liposomes. Cells internalized liposomes, increasing expression of the costimulatory molecule CD86 and inducing T lymphocyte proliferation.

Paracoccidioidomycosis associated with a heterozygous STAT4 mutation and impaired IFN-gama immunity

Background Mutations in genes affecting interferon-gama (IFN-gama) immunity have contributed to understand the role of IFN-gama in protection against intracellular pathogens. However, inborn errors in STAT4, which controls interleukin-12 (IL-12) responses, have not yet been reported. Our objective was to determine the genetic defect in a family with a history of paracoccidioidomycosis. Methods Genetic analysis was performed by whole-exome sequencing and Sanger sequencing. STAT4 phosphorylation (pSTAT4) and translocation to the nucleus, IFN-gama release by patient lymphocytes, and microbicidal activity of patient monocytes/macrophages were assessed. The effect on STAT4 function was evaluated by site-directed mutagenesis using a lymphoblastoid B cell line (B-LCL) and U3A cells. Results A heterozygous missense mutation, c.1952 A>T (p.E651V) in STAT4 was identified in the index patient and her father. Patient’s and father’s lymphocytes showed reduced pSTAT4, nuclear translocation, and impaired IFN-gama production. Mutant B-LCL and U3A cells also displayed reduced pSTAT4. Patient's and father's peripheral blood mononuclear cells and macrophages demonstrated impaired fungicidal activity compared with those from healthy controls that improved in the presence of recombinant human IFN-gama, but not rhIL-12. Conclusion Our data suggest autosomal dominant STAT4 deficiency as a novel inborn error of IL-12–dependent IFN-gama immunity associated with susceptibility to paracoccidioidomycosis.

Evaluation of cytotoxic effect of the combination of a pyridinyl carboxamide derivative and oxaliplatin on NCI-H1299 human non-small cell lung carcinoma cells.

Even with all improvements in both diagnostic and therapeutic techniques, lung cancer remains as the most lethal and prevalent cancer in the world. Therefore, new therapeutic drugs and new strategies of drug combination are necessary to provide treatments that are more efficient. Currently, standard therapy regimen for lung cancer includes platinum drugs, such as cisplatin, oxaliplatin, and carboplatin. Besides of the better toxicity profile of oxaliplatin when compared with cisplatin, peripheral neuropathy remains as a limitation of oxaliplatin dose. This study presents LabMol-12, a new pyridinyl carboxamide derivative with antileishmanial and antichagasic activity, as a new hit for lung cancer treatment, which induces apoptosis dependent of caspases in NCI-H1299 lung cancer cells both in monolayer and 3D culture. Moreover, LabMol-12 allows a reduction of oxaliplatin dose when they are combined, thereby, it is a relevant strategy for reducing the side effects of oxaliplatin with the same response. Molecular modeling studies corroborated the biological findings and suggested that the combined therapy can provide a better therapeutically profile effects against NSCLC. All these findings support the fact that the combination of oxaliplatin and LabMol-12 is a promising drug combination for lung cancer.

Dendritic Cells Stimulated by Cationic Liposomes.

Immunotherapy of cancer aims to harness the immune system to detect and destroy cancer cells. To induce an immune response against cancer, activated dendritic cells (DCs) must present tumor antigens to T lymphocytes of patients. However, cancer patients' DCs are frequently defective, therefore, they are prone to induce rather tolerance than immune responses. In this context, loading tumor antigens into DCs and, at the same time, activating these cells, is a tempting goal within the field. Thus, we investigated the effects of cationic liposomes on the DCs differentiation/maturation, evaluating their surface phenotype and ability to stimulate T lymphocytes proliferation in vitro. The cationic liposomes composed by egg phosphatidylcholine, 1,2-dioleoyl-3-trimethylammonium propane and 1,2-dioleoylphosphatidylethanolamine (50/25/25% molar) were prepared by the thin film method followed by extrusion (65 nm, polydispersity of 0.13) and by the dehydration-rehydration method (95% of the population 107 nm, polydispersity of 0.52). The phenotypic analysis of dendritic cells and the analysis of T lymphocyte proliferation were performed by flow cytometry and showed that both cationic liposomes were incorporated and activated dendritic cells. Extruded liposomes were better incorporated and induced higher CD86 expression for dendritic cells than dehydrated-rehydrated vesicles. Furthermore, dendritic cells which internalized extruded liposomes also provided stronger T lymphocyte stimulation. Thus, cationic liposomes with a smaller size and polydispersity seem to be better incorporated by dendritic cells. Hence, these cationic liposomes could be used as a potential tool in further cancer immunotherapy strategies and contribute to new strategies in immunotherapy.

Tolerogenic IDO(+) Dendritic Cells Are Induced by PD-1-Expressing Mast Cells.

Mast cells (MCs) are tissue resident cells, rich in inflammatory mediators, involved in allergic reactions, and with an increasingly recognized role in immunomodulation. Dendritic cells (DCs), on the other hand, are central to the determination of immune response patterns, being highly efficient antigen-presenting cells that respond promptly to changes in their microenvironment. Here, we show that direct cell contact between immature monocyte-derived DCs (iDCs) and MC bends DCs toward tolerance induction. DCs that had direct contact with MC (MC-iDC) decreased HLA-DR but increased PD-L1 expression and stimulated regulatory T lymphocytes, which expresses FoxP3(+), secrete TGF-ß and IL-10, and suppress the proliferation of mitogen-stimulated naïve T lymphocytes. Furthermore, MC-iDC expressed higher levels of indoleamine-2,3-deoxigenase (IDO), a phenomenon that was blocked by treatment of MC with anti-PD-1 or by the treatment of DCs with anti-PD-L1 or anti-PD-L2, but not by blocking of H1 and H2 histamine receptors on DCs. Contact with MC also increased phosphorylated STAT-3 levels in iDCs. When a STAT-3 inhibitor, JSI-124, was added to the DCs before contact with MC, the MC-iDC recovered their ability to induce allogeneic T cell proliferation and did not increase their IDO expression.

BFD-22 a new potential inhibitor of BRAF inhibits the metastasis of B16F10 melanoma cells and simultaneously increased the tumor immunogenicity.

Benzofuroxan is an interesting ring system, which has shown a wide spectrum of biological responses against tumor cell lines. We investigated, herein, the antitumor effects of benzofuroxan derivatives (BFDs) in vitro and in a melanoma mouse model. Cytotoxic effects of twenty-two BFDs were determined by MTT assay. Effects of BFD-22 in apoptosis and cell proliferation were evaluated using Annexin V-FITC/PI and CFSE staining. In addition, the effects in the cell cycle were assessed. Flow cytometry, western blot, and fluorescence microscopy analysis were employed to investigate the apoptosis-related proteins and the BRAF signaling. Cell motility was also exploited through cell invasion and migration assays. Molecular docking approach was performed in order to verify the BFD-22 binding mode into the ATP catalytic site of BRAF kinase. Moreover, the BFD-22 antitumor effects were evaluated in a melanoma murine model using B16F10. BFD-22 was identified as a potential hit against melanoma cells. BFD-22 induced apoptosis and inhibited cell proliferation of B16F10 cells. BFD-22 has suppressed, indeed, the migratory and invasive behavior of B16F10 cells. Cyclin D1 and CDK4 expression were reduced leading to cell cycle arrest at G0/G1 phase. Of note, phosphorylation of BRAF at Ser338 was strongly down-regulated by BFD-22 in B16F10 cells. The accommodation/orientation into the binding site of BRAF was similar of BAY43-9006 (co-crystallized inhibitor of BRAF, sorafenib). Importantly, BFD-22 presented in vivo antimetastatic effects and showed better therapeutic efficacy than sorafenib and taxol. BFD-22 can be considered as a new lead compound and, then, can be helpful for the designing of novel drug candidates to treat melanoma.

RPF151, a novel capsaicin-like analogue: in vitro studies and in vivo preclinical antitumor evaluation in a breast cancer model.

Capsaicin, the primary pungent component of the chili pepper, has antitumor activity. Herein, we describe the activity of RPF151, an alkyl sulfonamide analogue of capsaicin, against MDA-MB-231 breast cancer cells. RPF151 was synthetized, and molecular modeling was used to compare capsaicin and RPF151. Cytotoxicity of RPF151 on MDA-MB-231 was also evaluated by the 3-[4,5-dimethylthiazol-2-yl]-2,5diphenyltetrazolium bromide (MTT) assay. Cell cycle analysis, by flow cytometry, and Western blot analysis of cycle-related proteins were used to evaluate the antiproliferative mechanisms. Apoptosis was evaluated by phosphatidyl-serine externalization, cleavage of Ac-YVAD-AMC, and Bcl-2 expression. The production of reactive oxygen species was evaluated by flow cytometry. RPF151 in vivo antitumor effects were investigated in murine MDA-MB-231 model. This study shows that RPF151 downregulated p21 and cyclins A, D1, and D3, leading to S-phase arrest and apoptosis. Although RPF151 has induced the activation of TRPV-1 and TRAIL-R1/DR4 and TRAIL-2/DR5 on the surface of MDA-MB-231 cells, its in vivo antitumor activity was TRPV-1-independent, thus suggesting that RPF151 should not have the same pungency-based limitation of capsaicin. In silico analysis corroborated the biological findings, showing that RPF151 has physicochemical improvements over capsaicin. Overall, the activity of RPF151 against MDA-MB-231 and its lower pungency suggest that it may have a relevant role in cancer therapy.

Synergistic anti-tumor effects of the combination of a benzofuroxan derivate and sorafenib on NCI-H460 human large cell lung carcinoma cells.

Lung cancer is the most frequent and lethal human cancer in the world. Because is still an unsolved health issue, new compounds or therapeutic strategies are urgently needed. Furoxans are presented as potentials candidates for lung cancer treatment. Accordingly, we evaluated the efficacy of a benzofuroxan derivative, BFD-22, alone and combined with sorafenib against NCI-H460 cell line. We showed that BFD-22 has cytotoxic effects on the NCI-H460 cells. Importantly, the Combination Index (CI) evaluation revels that BFD-22 combined with sorafenib has a stronger cytotoxic effect. In addition, the combination induces apoptosis through extrinsic pathway, leading to TRAIL-R1/DR4-triggered apoptosis. Furthermore, BFD-22 combined with sorafenib increases ROS production and simultaneously reduces perlecan expression in the NCI-H460 cells. In accordance, tumor cells were arrested in the S-phase, and these anti-proliferative effects also inhibit cell migration. This is the first study reporting an advantage of BFD-22 combined with sorafenib as a new therapeutic strategy in the fight against lung cancer.

Mesenchymal stem cells derived from human exfoliated deciduous teeth (SHEDs) induce immune modulatory profile in monocyte-derived dendritic cells.

BACKGROUND: Mesenchymal stem cells have prominent immune modulatory properties, which may have clinical applications; however their major source, bone marrow, is of limited availability. On the other hand, mesenchymal stem cells derived from human exfoliated deciduous teeth (SHEDs) are readily accessible, but their immune regulatory properties have not been completely investigated. This study was designed, therefore, to evaluate the SHEDs influence on DCs differentiation, maturation, ability to activate T cells and to expand CD4(+)Foxp3(+) T cells. METHODOLOGY/PRINCIPAL FINDINGS: The experiments were based in cellular co-culture during differentiation and maturation of monocyte derived-DCs (moDCs), with, or not, presence of SHEDs. After co-culture with SHEDs, (moDCs) presented lower expression of BDCA-1 and CD11c, in comparison to DC cultivated without SHEDs. CD40, CD80, CD83 and CD86 levels were also decreased in mature DCs (mDCs) after co-cultivation with SHEDs. To assess the ability of SHEDs-exposed moDCs to modulate T cell responses, the former were separated from SHEDs, and co-cultured with peripheral blood lymphocytes. After 5 days, the proliferation of CD4(+) and CD8(+) T cells was evaluated and found to be lower than that induced by moDCs cultivated without SHEDs. In addition, an increase in the proportion of CD4(+)Foxp3(+)IL-10(+) T cells was observed among cells stimulated by mature moDCs that were previously cultivated with SHEDs. Soluble factors released during co-cultures also showed a reduction in the pro-inflammatory cytokines (IL-2, TNF-α and IFN-γ), and an increase in the anti-inflammatory molecule IL-10. CONCLUSION/SIGNIFICANCE: This study shows that SHEDs induce an immune regulatory phenotype in moDCs cells, evidenced by changes in maturation and differentiation rates, inhibition of lymphocyte stimulation and ability to expand CD4(+)Foxp3(+) T cells. Further characterization and validation of this phenomenon could support the use of SHEDs, directly or indirectly for immune modulation in the clinical practice.

Dendritic cells from X-linked hyper-IgM patients present impaired responses to Candida albicans and Paracoccidioides brasiliensis.

BACKGROUND: Patients with X-linked hyper-IgM syndrome (X-HIGM) due to CD40 ligand (CD40L) mutations are susceptible to fungal pathogens; however, the underlying susceptibility mechanisms remain poorly understood. OBJECTIVE: To determine whether monocyte-derived dendritic cells (DCs) from patients with X-HIGM exhibit normal responses to fungal pathogens. METHODS: DCs from patients and controls were evaluated for the expression of costimulatory (CD80 and CD86) and MHC class II molecules and for their ability to produce IL-12 and IL-10 in response to Candida albicans and Paracoccidioides brasiliensis. We also evaluated the ability of C albicans- and P brasiliensis-pulsed mature DCs to induce autologous T-cell proliferation, generation of T helper (T(H)) 17 cells, and production of IFN-γ, TGF-ß, IL-4, IL-5, and IL-17. RESULTS: Immature DCs from patients with X-HIGM showed reduced expression of CD80, CD86, and HLA-DR, which could be reversed by exogenous trimeric soluble CD40L. Most important, mature DCs from patients with X-HIGM differentiated by coculturing DCs with fungi secreted minimal amounts of IL-12 but substantial amounts of IL-10 compared with mature DCs from normal individuals. Coculture of mature DCs from X-HIGM patients with autologous T cells led to low IFN-γ production, whereas IL-4 and IL-5 production was increased. T-cell proliferation and IL-17 secretion were normal. Finally, in vitro incubation with soluble CD40L reversed the decreased IL-12 production and the skewed T(H)2 pattern response. CONCLUSION: Absence of CD40L during monocyte/DC differentiation leads to functional DC abnormalities, which may contribute to the susceptibility to fungal infections in patients with X-HIGM.

Cytotoxic effects of butanolic extract from Pfaffia paniculata (Brazilian ginseng) on cultured human breast cancer cell line MCF-7.

Roots of Pfaffia paniculata have been well documented for multifarious therapeutic values and have also been used for cancer therapy in folk medicine. This study has been performed in a human breast tumor cell line, the MCF-7 cells. These are the most commonly used model of estrogen-positive breast cancer, and it has been originally established in 1973 at the Michigan Cancer Foundation from a pleural effusion taken from a woman with metastatic breast cancer. Butanolic extract of the roots of P. paniculata showed cytotoxic effect MCF-7 cell line, as determined with crystal violet assay, cellular death with acridine orange/ethidium bromide staining, and cell proliferation with immunocytochemistry of bromodeoxyuridine (BrdU). Subcellular alterations were evaluated by electron microscopy. Cells treated with butanolic extract showed degeneration of cytoplasmic components and profound morphological and nuclear alterations. The results show that this butanolic extract indeed presents cytotoxic substances, and its fractions merit further investigations.