Telma Miyuki Oshiro

Polymorphisms in inflammasome' genes and susceptibility to HIV-1 infection.

Abstract:The involvement of inflammasome genes in the susceptibility to HIV-1 infection was investigated. Twelve single nucleotide polymorphisms within NLRP1, NLRP3, NLRC4, CARD8, CASP1, and IL1B genes were analyzed in 150 HIV-1–infected Brazilian subjects and 158 healthy controls. The 2 polymorphisms rs10754558 in NLRP3 and rs1143634 in IL1B were significantly associated to the HIV-1 infection. These findings supported the previously hypothesized involvement of NALP3-inflammasome in HIV-1 pathogenesis, underlining once more the key role of inflammation and innate immunity in the susceptibility to HIV-1 infection.

HIV-1 induces NALP3-inflammasome expression and interleukin-1β secretion in dendritic cells from healthy individuals but not from HIV-positive patients.

Objective:NALP3-inflammasome is an innate mechanism, alternative to type-1 interferon, which is able to recognize nucleic acids and viruses in the cytoplasm and to induce pro-inflammatory response. Here, we hypothesized the involvement of inflammasome in the early defense against HIV-1 and in the full maturation of dendritic cells: for this, we evaluated the response of dendritic cells pulsed with HIV-1 in terms of inflammasome activation in healthy donors. Moreover, inflammasome response to HIV was evaluated in HIV-infected individuals. Design and methods:Monocyte-derived dendritic cells isolated from 20 healthy individuals (HC-DC) and 20 HIV-1-infected patients (HIV-DC) were pulsed with alditrithiol-2-inactivated HIV-1. We then analyzed inflammasome genes expression and interleukin-1&bgr; (IL-1&bgr;) secretion. Results:In HC-DC, HIV-1 induced higher NLRP3/NALP3 mRNA expression compared with other inflammasome genes such as NALP1/NLRP1 or IPAF/NLRC4 (P < 0.001). This augmented expression was accompanied by CASP1-increased and IL1B-increased mRNA levels and by a significant increment of IL-1&bgr; secretion (P < 0.05). Otherwise, HIV-1 failed to activate inflammasome and cytokine production in HIV-DC. HIV-DC showed an increased NLRP3/NALP3 basal expression, suggesting a chronic inflammatory profile of patients’ immune cells. Conclusion:HIV-1 was able to induce a NALP3-inflammasome response in healthy individuals, indicating that this inflammasome could play a role in the first steps of HIV-1 infection; the consequent inflammatory process may be important for directing host immune response against the virus and/or disease progression. HIV-DC seemed to be chronically activated, but unresponsive against pathogens. Our findings could be of interest considering the ongoing research about dendritic cell manipulation and therapeutic strategies for AIDS involving dendritic cell-based immune-vaccines.

PAS-1, a protein affinity purified from Ascaris suum worms, maintains the ability to modulate the immune response to a bystander antigen

Helminth infections and parasite components have potent immunomodulatory effects on a hosts immune system. In the present study, we investigated the effect of PAS‐1, a protein component of Ascaris suum adult worms recognized by a monoclonal antibody (MAIP‐1), on humoral and cell‐mediated responses to a bystander antigen (ovalbumin [OVA]). MAIP‐1 recognized only one of the three polypeptide chains of PAS‐1, but neutralized the suppressive effect of the whole worm extract on OVA‐specific antibody production. PAS‐1 inhibited antibody production against a T‐cell‐dependent, but not a T‐cell‐independent, antigen in a dose‐dependent way. IgM, IgG1, IgG2b, and also IgE and anaphylactic IgG1 levels were downregulated. In addition, PAS‐1 inhibited OVA‐specific delayed type hypersensitivity reactions in the footpad of mice, showing a potent immunosuppressive activity on both Th1 and Th2 responses that seems to be mediated by the induction of large amounts of IL‐10 and IL‐4. Indeed, PAS‐1‐specific spleen cells secreted sevenfold more IL‐10 and threefold more IL‐4 than OVA‐specific cells in response to in vitro restimulation with the respective antigens. In conclusion, we showed that PAS‐1, a single protein component from A. suum, maintains all its immunosuppressive properties.

Kinetics of IFN-gamma, TNF-alpha, IL-10 and IL-4 production by mononuclear cells stimulated with gp43 peptides, in patients cured of paracoccidioidomycosis

We analyzed the kinetics of cytokine production by mononuclear cells from 17 patients who had been treated for paracoccidioidomycosis, using the stimulus of gp43 peptide groups (43 kDa glycoprotein of Paracoccidioides brasiliensis) at 0.1 and 1 microM, gp43 (1 microg/ml) and crude Paracoccidioides brasiliensis antigen (PbAg; 75 microg/ml). IFN-gamma production was a maximum at 144 hours in relation to the G2 and G8 peptide groups at 1 microM and was greatest at 144 hours when stimulated by gp43 and by PbAg. The maximum TNF-alpha production was at 144 hours for the G2 group (0.1 microM) and for gp43. IL-10 production was highest after 48 and 72 hours for G7 and G6 at 1 microM, respectively. We also suggest the best time for analysis of IL4 production. These results may contribute towards future studies with gp43 peptides and encourage further investigations with the aim of understanding the influence of these peptides on the production of inflammatory and regulatory cytokines.

Genotyping and differential expression analysis of inflammasome genes in sporadic malignant melanoma reveal novel contribution of CARD8, IL1B and IL18 in melanoma susceptibility and progression

Sporadic melanoma malignancy is correlated with constitutive secretion of IL-1β in transformed melanocytes suggesting the involvement of inflammasome in melanoma. Common variants in inflammasome genes are known to affect IL-1β expression. To investigate the contribution of inflammasome genetics in melanoma development and progression and to identify a potential prognostic marker, the distribution of selected inflammasome SNPs was analysed in a Brazilian case/control cohort of sporadic malignant melanoma (SMM) and then the expression of inflammasome components was evaluated in melanoma biopsies. Allele and gene-specific Taqman assays were implied for genotyping of case/control DNA samples and for relative expression analysis in skin biopsies respectively. CARD8 rs6509365 was found to be significantly more common in healthy volunteers than in SMM patients suggesting a protection effect of this variant towards melanoma development. Accordingly, CARD8 expression was found to be reduced in nevus compared to melanoma biopsies. Upon stratification, NLRP1 rs11651270 and CARD8 rs2043211 were found associated with nodular melanoma; IL1B rs1143643 to a lower value of Breslow index; IL18 rs5744256 to melanoma development in sun sensitive individuals. As expected, IL1B expression was up-regulated in tumour biopsies especially in metastatic samples, whereas IL18 was down-regulated compared to nevus. Our results demonstrated for the first time the contribution of inflammasome genes CARD8, IL1B and IL18 in SMM.

Differential inflammasome expression and IL-1β secretion in monocyte-derived dendritic cells differentiated with IL-4 or IFN-α

BackgroundNLRP3-inflammasome activation was evaluated in monocyte-derived dendritic cells (DC) obtained through IL-4 (IL4-DC) or IFN-α (IFN-DC) protocols and pulsed with chemically inactivated HIV-1. Inflammasome’ genes expression and IL-1β secretion were compared in DC isolated from 15 healthy subjects (HC) and 10 HIV-1 infected individuals (HIV+).FindingsWhether HIV was able to increased NLRP3-inflammasome genes expression and IL-1β secretion in IL4-DC from HC, the induction of inflammasome appeared significantly reduced in IFN-DC from HC, suggesting a different responsive state of IFN-DC compared to IL4-DC. No inflammasome activation was observed in IL4-DC as well as in IFN-DC derived from HIV + subjects, confirming previous findings on “unresponsive” state of DC derived from HIV + possibly due to chronic inflammatory state of these individuals.ConclusionsOur results showed that IFN-α differently modulates inflammasome expression during monocytes-DC in vitro differentiation. These findings could be of interest considering the on-going research about DC manipulation and therapeutic strategies for HIV + involving DC-based immune-vaccines.

Dendritic cell immunotherapy for HIV infection: from theory to reality

Knowledge concerning the immunology of dendritic cells (DCs) accumulated over the last few decades and the development of methodologies to generate and manipulate these cells in vitro has made their therapeutic application a reality. Currently, clinical protocols for DC-based therapeutic vaccine in HIV-infected individuals show that it is a safe and promising approach. Concomitantly, important advances continue to be made in the development of methodologies to optimize DC acquisition, as well as the selection of safe, immunogenic HIV antigens and the evaluation of immune response in treated individuals.

Data on inflammasome gene polymorphisms of patients with sporadic malignant melanoma in a Brazilian cohort

This article presents data related to our another article entitled, Genotyping and differential expression analysis of inflammasome genes in sporadic malignant melanoma reveal novel contribution of CARD8, IL1B and IL18 in melanoma susceptibility and progression (W.C. Silva, T.M. Oshiro, D.C. Sá, D.D.G.S. Franco, C. Festa Neto, A. Pontillo, 2016) [2]. Data presented here refers to the distribution of selected inflammasome SNPs in a Brazilian case/control cohort. We have identified 4 inflammasome related Single Nucleotide Polymorphisms (SNPs) for CARD8 (rs6509365); IL1B (rs1143643) and IL18 (rs5744256 and rs1834481) related to melanoma susceptibility/protection. This data can serve as a potential prognostic marker in sporadic malignant melanoma.

Development of potent class II transactivator gene delivery systems capable of inducing de novo MHC II expression in human cells, in vitro and ex vivo

Class II transactivator (CIITA) induces transcription of major histocompatibility complex (MHC) II genes and can potentially be used to improve genetic immunotherapies by converting non-immune cells into cells capable of presenting antigens to CD4+ T cells. However, CIITA expression is tightly controlled and it remains unclear whether distinct non-immune cells differ in this transactivator regulation. Here we describe the development of gene delivery systems capable of promoting the efficient CIITA expression in non-immune cell lines and in primary human cells of an ex vivo skin explant model. Different human cell types undergoing CIITA overexpression presented high-level de novo expression of MHC II, validating the delivery systems as suitable tools for the CIITA evaluation as a molecular adjuvant for gene therapies.

Dendritic cells primed with a chimeric plasmid containing HIV-1-gag associated with lysosomal-associated protein-1 (LAMP/gag) is a potential therapeutic vaccine against HIV

The decline in number and function of T cells is a hallmark of HIV infection, and preservation or restoration of HIV‐specific cellular immune response is a major goal of AIDS treatment. Dendritic cells (DCs) play a key role in the initiation and maintenance of the immune response, and their use as a vaccine vehicle is a promising strategy for enhancing vaccine efficacy. We evaluated the potential of DC‐mediated immunization with a DNA vaccine consisting of HIV‐1‐p55gag (gag, group‐specific antigen) associated to lysosomal associated protein (LAMP) sequence (LAMP/gag vaccine). Immunization of mice with mouse DCs transfected with LAMP/gag (Lg‐mDCs) stimulated more potent B‐ and T‐cell responses than naked DNA or DCs pulsed with inactivated HIV. Anti‐Gag antibody levels were sustained for at least 3 mo after immunization, and recall T‐cell responses were also strongly detected at this time point. Human DCs transfected with LAMP/gag (Lg‐hDCs) were also activated and able to stimulate greater T‐cell response than native gag‐transfected DCs. Coculture between Lg‐hDCs and T lymphocytes obtained from patients with HIV resulted in upregulation of CD38, CD69, HLA‐DR, and granzyme B by CD4+ and CD8+ T cells, and increased IFN‐γ and TNF‐α production. These results indicate that the use of LAMP/gag‐DC may be an efficient strategy for enhancing immune function in patients with HIV.—Lucas, C. G. D. O., Matassoli, F. L., Peçanha, L. M. T., Santillo, B. T., Oliveira, L. M. D. S., Oshiro, T. M., Marques, E. T. D. A., Jr., Oxenius, A., de Arruda, L. B. Dendritic cells primed with a chimeric plasmid containing HIV‐1‐gag associated with lysosomal‐associated protein‐1 (LAMP/gag) is a potential therapeutic vaccine against HIV. FASEB J. 30, 2970‐2984 (2016). www.fasebj.org