In vitro Azole antifungals susceptibility of Candida spp. isolates from HIV-infected patients with periodontitis.

OBJECTIVE: The objective of the present study was to determine the in vitro Azole antifungals susceptibility of Candida spp. strains isolated from HIV-positive patients with periodontitis. METHODS: Oral examination was performed in 500 HIV-positive patients, of which 228 were included in the study for having periodontitis which and separated in two groups based on their TCD4+ T-cells: (A) n = 110 (≤200 CD4+); (B) n = 118 (>200 CD4+). Candida spp. were isolated from the subgingival biofilm and crevicular fluid by seeding on CHROMagar plates and confirmed by endpoint PCR and MALDI-TOF. The susceptibility test in vitro for five antifungals was performed using the disc diffusion method. RESULTS: From the 228 HIV-positive patients with periodontitis, 174 were positive to Candida spp., and 204 isolations were obtained. 138 (67.64%) were C. albicans, and 66 (32.35%) were Candida non-albicans species. The most frequent Candida non-albicans species in order of frequency were C. glabrata with 48 (23.52%), C. tropicalis with 10 (4.9%), C. krusei with 7 (3.43%), and C. dubliniensis with 1 (0.49%). All species presented resistance to any antifungal: 149 to 5-fluorocytosine (73.0%), 149 to fluconazole (73.0%), and 144 to voriconazole (70.7%). Miconazole and econazole presented the highest susceptibility rates with 129 (63.2%) and 130 (63.7%) isolations, respectively. CONCLUSION: The Candida spp. involved in periodontitis of HIV-positive patients have a multi-resistant feature. It is necessary to implement recurrent research regarding the antifungal resistance of the Candida spp. that take part in periodontitis pathogenesis to promote an effective treatment in HIV patients.

ZBTB gene expression in HIV patients: a possible new molecular mechanism of viral control.

HIV infects its target cell and integrates into its genome as an essential step in its replication cycle. Proviral DNA is also subjected to the same transcriptional regulation as the host cell genome by its own transcriptional factors, with activating or repressive activity. There is a clear interaction between the presence of transcriptional repressors and a decrease in the rate of HIV replication, promoting gene silencing in infected cells, which serve as viral reservoirs. This represents a major obstacle for HIV eradication. The ZBTB gene family comprises 49 genes that encode transcription factors that have a repressor function in differentiation and development of cells of the lymphopoietic lineage, including the main target cells of HIV, CD4+ T cells. In this cross-sectional study, we evaluated the expression profile of ZBTB genes in CD4+ T cells of HIV-positive individuals with different levels of infection control. We found upregulation of gene expression of ZBTB4 (p < 0.01), ZBTB7B (p < 0.001), and ZBTB38 (p < 0.05) and downregulation of ZBTB16 (p < 0.01) in HIV-positive patients compared to HIV-negative individuals. Interestingly, in a deeper analysis, we observed that elite controllers had the highest levels of expression of the ZBTB38, ZBTB2, HIC1, ZBTB7A, ZBTB7B (ThPOK) and ZBTB4 genes, showing 2.56- to 7.60-fold upregulation compare to the ART-naïve group. These results suggest a possible contribution of these ZBTB transcriptional repressors in HIV-positive patients and a possible new molecular mechanism of viral control.

Association of intestinal and systemic inflammatory biomarkers with immune reconstitution in HIV+ patients on ART.

BACKGROUND: HIV infection is characterized by CD4+ T-cells depletion related to gut damage, microbial translocation, immune activation and intestinal and systemic low-grade inflammation. With the use of antiretroviral treatment, these alterations in HIV+ patients reach similar levels to HIV- controls. However, almost 20% patients have deficient immune reconstitution of CD4+ T-cells, which make them more susceptible to develop non-AIDS and AIDS comorbidities. METHODS: HIV+ patients on ART, with sustained virologic control were grouped according to their immune reconstitution as: immunological responders (n = 18) and immunological non-responders (n = 18); also, HIV- controls were enrolled (n = 14). CD4+ and CD8+ T-cell activation (HLA-DR+ and CD38+ single and co-expression) were measured by flow cytometry. Serum levels of sCD14, sCD163, lipopolysaccharide, I-FABP, sST2, as well as fecal levels of calprotectin, lactoferrin and secretory IgA were evaluated by ELISA. Levels of C-reactive protein were determined by a high sensibility singleplex bead-based immunoassay. Serum and fecal concentrations of proinflammatory cytokines were quantified by multiplex bead-based immunoassay. RESULTS: HLA-DR+ and CD38+ co-expression, as well as median fluorescence intensity in CD4+ and CD8+ T-cells subpopulations was greater in immunological non-responders group, after normalization and fold change calculation. Similarly, this group presented higher levels of sCD14, C-reactive protein, as well as fecal calprotectin and lactoferrin. Furthermore, both HIV+ groups showed elevated levels of proinflammatory cytokines in stool. CONCLUSIONS: Our data suggests that despite the virologic control, HIV+ patients under treatment with deficient immune reconstitution showed elevation of both innate and T-cells immune activation, as well as intestinal and systemic inflammation. However, some patients with CD4+ T-cells count above 350 cells/µL also presented these alterations. Future studies are necessary to evaluate the dynamics of multiple systemic and intestinal biomarkers in diverse types of HIV+ patients, as such as their clinical impact.

[Apoptosis modulation by human papillomavirus]. / Modulación de la apoptosis por el virus del papiloma humano.

One of the most important processes to keep the homeostasis in organisms is the apoptosis, also called programmed cell death. This mechanism works through two pathways: The intrinsic or mitochondrial, which responds to DNA damage and extern agents like UV radiation; and the extrinsic or receptor-mediated, which binds to their ligands to initiate the apoptotic trail. The evasion of apoptosis is one of the main causes of cellular transformation to malignity. Many viruses had shown capacity to modify the apoptotic process; among them is the human papillomavirus, which, by means of its oncoproteins, interferes in pathways, reacting with the receptors and molecules and participating in the death mechanism. This creates ideal conditions for cancer development.

Uno de los procesos más importantes para el mantenimiento de la homeostasis en el organismo es la apoptosis, también denominada muerte celular programada. Este mecanismo funciona por medio de dos vías: la intrínseca o mitocondrial, que responde a daños al ADN y a agentes externos, como la radiación UV; y la extrínseca o mediada por receptores, los que se unen a sus ligandos para iniciar la cascada apoptótica. La evasión de la apoptosis es una de las principales causas de transformación celular hacia la malignidad. Muchos virus han mostrado capacidades para modificar el proceso apoptótico, entre ellos el VPH, el cual interfiere por medio de sus oncoproteínas en ambas vías y reacciona con los receptores y las moléculas que participan en el mecanismo de muerte y crea condiciones propicias para el desarrollo del cáncer.

Proapoptotic CD95L levels in normal human serum and sera of breast cancer patients.

The CD95 pathway is a critical apoptotic pathway used by immune cells to avoid cancer development. CD95 ligand (CD95L) is found in several forms, as a cell membrane-associated form, a soluble metalloprotease-cleaved form, and a soluble but membrane-bound CD95L released on cell-derived exosomes. In this study, we used a cell-based assay to evaluate the activity of proapoptotic CD95L in sera from healthy individuals and breast cancer patients. We confirmed that our cell-based assay using Jurkat cells was sensitive to the presence of proapoptotic CD95L in serum, and apoptosis induction by mechanisms other than CD95 was discriminated using apoptosis-resistant Jurkat subclones. Our results indicated a proapoptotic potential of normal serum that involved CD95L. Sera from breast cancer patients exhibited significantly decreased apoptosis induction, due to increased CD95 receptor levels compared with healthy women. Apoptotic potential tended to decrease as the Breast Imaging Reporting and Data System grade increased, and we observed restoration of proapoptotic potential after tumor removal. The CD95L in serum responsible for apoptotic induction was associated with high-molecular-weight particles, perhaps with exosomes. The sera of healthy individuals generally contain a proapoptotic environment, and this property is mainly maintained by the presence of CD95L. Furthermore, measurement of CD95L-mediated apoptosis induction by sera could be a useful parameter to be evaluated during cancer development and therapeutic response.

Restoration of WNT4 inhibits cell growth in leukemia-derived cell lines.

BACKGROUND: WNT signaling pathways are significantly altered during cancer development. Vertebrates possess two classes of WNT signaling pathways: the "canonical" WNT/ß-catenin signaling pathway, and the "non-canonical" pathways including WNT/Ca²âº and WNT/Planar cell polarity [PCP] signaling. WNT4 influences hematopoietic progenitor cell expansion and survival; however, WNT4 function in cancer development and the resulting implications for oncogenesis are poorly understood.The aim of this study was twofold: first, to determine the expression of WNT4 in mature peripheral blood cells and diverse leukemia-derived cells including cell lines from hematopoietic neoplasms and cells from patients with leukemia; second, to identify the effect of this ligand on the proliferation and apoptosis of the blast-derived cell lines BJAB, Jurkat, CEM, K562, and HL60. METHODS: We determined WNT4 expression by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) in peripheral blood mononuclear cells (PBMCs) and T- and B-lymphocytes from healthy individuals, as well as from five leukemia-derived cell lines and blasts derived from patients with leukemia. To analyze the effect of WNT4 on cell proliferation, PBMCs and cell lines were exposed to a commercially available WNT4 recombinant human protein. Furthermore, WNT4 expression was restored in BJAB cells using an inducible lentiviral expression system. Cell viability and proliferation were measured by the addition of WST-1 to cell cultures and counting cells; in addition, the progression of the cell cycle and the amount of apoptosis were analyzed in the absence or presence of WNT4. Finally, the expression of WNT-pathway target genes was measured by qRT-PCR. RESULTS: WNT4 expression was severely reduced in leukemia-derived cell lines and blasts derived from patients with leukemia. The exposure of cell lines to WNT4 recombinant protein significantly inhibited cell proliferation; inducing WNT4 expression in BJAB cells corroborated this observation. Interestingly, restoration of WNT4 expression in BJAB cells increased the accumulation of cells in G1 phase, and did not induce activation of canonical WNT/ß-catenin target genes. CONCLUSIONS: Our findings suggest that the WNT4 ligand plays a role in regulating the cell growth of leukemia-derived cells by arresting cells in the G1 cell cycle phase in an FZD6-independent manner, possibly through antagonizing the canonical WNT/ß-catenin signaling pathway.