No description available.

The HIV protein, Vpr, is a multifunctional accessory protein critical for efficient viral infection of target CD4+ T cells and macrophages. Vpr is incorporated into virus particles and functions to transport the preintegration complex into the nucleus where the process of viral integration into the host genome is completed. This action is particularly important in macrophages, which as a result of their terminal differentiation and non-proliferative status, would be otherwise more refractory to HIV infection. Vpr has several other critical functions including activation of HIV-1 LTR transcription, cell-cycle arrest due to DCAF-1 binding, and both direct and indirect contributions to T-cell dysfunction. The interactions of Vpr with molecular pathways in the context of macrophages, on the other hand, support accumulation of a persistent reservoir of HIV infection in cells of the myeloid lineage. The role of Vpr in the virus life cycle, as well as its effects on immune cells, appears to play an important role in the immune pathogenesis of AIDS and the development of HIV induced end-organ disease. In view of the pivotal functions of Vpr in virus infection, replication, and persistence of infection, this protein represents an attractive target for therapeutic intervention. Numerous studies have reported that Vpr alters NF-kappa B signaling in various cells, however, the findings have so far been largely conflicting with reports both stimulatory and inhibitory effects of Vpr. Our aim was to investigate the role of Vpr signaling in myeloid cells and address discrepancies that have been reported in the field. Our results show that Vpr expressed intracellularly is inhibitory to NF-kappa B, while extracelluar Vpr may have some stimulatory effects. Consistent with this notion, we report that Vpr has inhibitory effects that are specific to the TNF-alpha pathway, but not the LPS pathway, suggesting that multiple targets of Vpr may exist for NF-kappa B regulation. Further, we identify VprBP as one possible cellular component of Vpr's regulation of I-kappa B-alpha in response to TNF-alpha stimulation. We did not identify such a role for HSP27, which instead seems to inhibit Vpr functions. Finally, our findings suggest that NF-kappa B regulation by Vpr is further changed by the presence of other HIV-1 components within the cells, as U1 cells lacking Vpr were unexpectedly less responsive to TNF-alpha than those cells that had normal Vpr expression levels. This data suggests that Vpr may serve an important role in vivo by selectively inhibiting immune activation while stimulating NF-kappa B mediated viral production in HIV-1 infected T-cells and myeloid cells. M-CSF is a cytokine that promotes monocyte differentiation and survival. When over-expressed, M-CSF contributes to pathology in a wide variety of diseases including osteoporosis, obesity, certain human cancers, and in HIV-1 infection, particularly with respect to monocyte/macrophage infection and the development of HIV-1. In this study, our aim is to expand on the current knowledge of M-CSF regulation by NF-kappa B, a prominent transcription factor during inflammation and HIV-1 infection. Our results suggest that TNF-alpha promotes M-CSF secretion in macrophages and activates the -1310/+48 bp M-CSF promoter in Mono-Mac 1 cells. Inhibitors of the NF-kappa B pathway, diminish this response. We identified four putative NF-kappa B and four C/EBP-beta binding sites within the M-CSF promoter. Our findings using M-CSF promoter constructs mutated at individual NF-kappa B locations suggest these sites are redundant with respect to M-CSF promoter regulation. TNF-alpha treatment promoted NF-kappa B p65 binding to the M-CSF promoter in PMA treated U937 cells chronically infected with HIV-1 (U1 cells), but not in PMA treated uninfected U937 cells, suggesting that the presence of HIV-1 increases the NF-kappa B response. In conclusion, our findings demonstrate that NF-kappa B induces M-CSF expression on a promoter level via multiple functional NF-kappa B binding sites and that this pathway is likely relevant in HIV-1 infection of macrophages. The oncogenic potential of M-CSF receptor has been has been suggested over thirty years ago, however, few current studies have focused on the role of the receptor in AML. In a clinical trial for AML, Sunitinib was found to hold some efficacy for treating the disease. The authors hypothesized that the primary therapeutic target of Sunitinib in AML is FLT3 kinase. However, FLT3 inhibition alone has not been shown to recapitulate all the effects of Sunitinib in vitro and, furthermore, the drug is also known to have cross reactivity to other potential oncogenic receptors. In this study, we treated three myeloid cell lines, Mono-Mac 1, THP-1 and U937 with Sunitinib and a proprietary cFMS inhibitor from Johnson and Johnson to test the anti-cancer effect in of such treatment. We observed that only Mono-Mac 1 cells had diminished proliferation in vitro. Mono-Mac 1 cells had inhibited ERK as a result of cFMS inhibition and showed a dose dependent increase in cFMS expression with both Sunitinib and J&J cFMS-1 treatment. Our results suggest potential for cFMS as an important target of Sunitinib or other similar drugs AML, either independently or in combination with other targets. Alternatively, cFMS may be a marker for differentiation of AML and may be linked with responsiveness to certain therapeutics. In both cases, the future study of cFMS may produce more targeted therapeutic approaches and may be a suitable tool for the development of personalized medicine for AML. / Biomedical Neuroscience

Les macrophages (MΦ), des cellules clefs de la réponse immunitaire peuvent répondre à des contaminants environnementaux comme les particules diesel (DEP), des polluants atmosphériques récemment classés cancérigènes pour l'Homme. Les MΦ sont des cellules hétérogènes et plastiques qui s'activent en fonction de leur microenvironnement soit en MΦ M1 (dits classiquement activés ou pro-inflammatoires) sous l'effet de l'INFγ et du LPS soit en MΦ M2 (dits alternativement activés ou réparateurs) sous l'effet de l'IL-4 et/ou de l'IL-13. Les effets des DEP sur la polarisation M1/M2 des MΦ restent peu documentés. Nous avons dans un premier temps caractérisé l'expression des marqueurs des MΦ différenciés in vitro en présence de M-CSF à partir de monocytes humains et polarisés en sous-type M1 ou M2. Nos principaux résultats montrent que les MΦ différenciés au M-CSF considérés comme des MΦ anti-inflammatoires, sont en réalité capables de s'activer vers un phénotype M1 après une stimulation au LPS/IFNγ. De plus, les marqueurs mis en évidence au cours de ce travail ont permis d'évaluer l'impact d'extraits organiques de DEP (DEPe) sur la polarisation des MΦ et plus généralement sur leur physiologie. Les DEPe altèrent l'expression de certains marqueurs M1 et M2 des MΦ, sans toutefois provoquer d'inhibition globale des processus de polarisation M1 et M2 ou de transition d'un phénotype vers un autre. Cette altération du phénotype est associée à une diminution de la réponse inflammatoire LPS-dépendante dans les MΦ M1 et des capacités chimiotactiques des MΦ M2. Les DEPe diminuent la sécrétion de certaines cytokines et chimiokines comme l'IL-6, l'IL-12p40 et le CCL18 via l'activation d'AhR et/ou de Nrf2. Parallèlement, nous montrons que les MΦ M1 et M2 exposés aux DEPe sécrètent le platelet deried growth factor B (PDGF-B), un facteur de croissance profibrosant, via l'activation d'AhR en quantité suffisante pour stimuler la prolifération de fibroblastes pulmonaires. Au total, ces travaux démontrent que les DEP possèdent des propriétés immunotoxiques vis-à-vis de la physiologie des macrophages humains polarisés in vitro. Cette immunotoxicité pourrait participer aux effets délétères de ces contaminants environnementaux urbains sur la santé humaine. / Macrophages (MΦ), well-known to play a key role in immune response, also respond to environmental toxic chemicals such as diesel exhaust particles (DEP), an air pollutant recently classified as carcinogenic to humans. MΦ are heterogeneous and plastic cells which activate according to their microenvironment into either an M1 subtype (so called classically activated or pro-inflammatory) under IFNγ and LPS stimulation or an M2 subtype (so called alternatively activated or anti-inflammatory) under IL-4 and/or IL-13 stimulation. However, potential effects of DEPs on M1/M2 MΦ polarization remain poorly documented. First, we characterized the expression marker of in vitro M-CSF-differentiated MΦ from human monocytes and activated into the M1 or M2 subtypes. Our main results show that M-CSF-generated MΦ considered as anti-inflammatory are actually able to switch to an M1 phenotype after IFNγ/LPS stimulation. Furthermore, the markers identified in this study were used to assess the impact of organic extracts of DEP (DEPe) on MΦ polarization and more generally on their physiology. DEPe alter some M1 and M2 markers expressed by polarized MΦ, without causing the overall inhibition of the M1 and M2 polarization process or the switch to a different phenotype. This phenotype alteration is associated with a decrease in the LPS-dependent inflammatory response in M1 MΦ and the chemotactic capacities in M2 MΦ. DEPe decrease the secretion of some cytokines and chemokines such as IL-6, IL-12p40 and CCL18 via AhR and/or Nrf2 activation. At the same time, we show that M1 and M2 MΦ in response to DEPe are able to secrete a sufficient level of a pro-fibrotic growth factor, the platelet derived growth factor B (PDGF-B) via AhR activation, leading to stimulation of lung fibroblast proliferation. Finally, these works show that DEPe have immunotoxic properties with regards to the physiology of human in vitro polarized MΦ. This immunotoxicity may then contribute to the deleterious effects of these urban environmental contaminants on human health.

Please read the abstract on page 3 in the dissertation. / Dissertation (MSc)--University of Pretoria, 2011. / Chemical Pathology / unrestricted

No description available.

No description available.

For many years, it has been known that Rheumatoid arthritis (RA) is a negative risk factor for the development of Alzheimer’s disease (AD). It has been commonly assumed that RA patients’ usage of non-steroidal anti-inflammatory drugs (NSAIDs) have helped prevent the onset and progression of AD pathogenesis. Furthermore, experiments in animal models of Alzheimer’s disease have looked to inhibit inflammation, and have demonstrated some efficacy against AD-like pathology in these models. Thus many NSAID clinical trials have been performed over the years, but all have proven unsuccessful in AD patients. This suggests that intrinsic factors within RA pathogenesis itself may underlie RA’s protective effect. My dissertation research goal was to investigate this inverse relationship between RA and AD, in order to more precisely pinpoint critical events in AD pathogenesis toward developing therapeutic strategies against AD. It seemed improbable that any secreted factors, produced in RA pathogenesis, could maintain high enough concentrations in the circulatory system to cross the blood brain barrier and inhibit AD pathogenesis, without affecting all other organ systems. It did seem possible that the leukocyte populations induced in RA, could traverse the circulatory system, extravasate into the brain parenchyma, and impede or reverse AD pathogenesis. We thus investigated the colony-stimulating factors, which are up-regulated in RA and which induce most of RA’s leukocytosis, on the pathology and behavior of transgenic AD mice. We found that G-CSF and more significantly, GM-CSF, reduced amyloidosis throughout the treated brain hemisphere one week following bolus intrahippocampal administration into AD mice. We then found that 20 days of subcutaneous injections of GM-CSF (the most amyloid-reducing CSF in the bolus experiment) significantly reduced brain amyloidosis and completely reversed cognitive impairment in aged cognitively-impaired AD mice, while increasing hippocampal synaptic area and microglial density. These findings, along with two decades of accrued safety data using Leukine, the recombinant human GM-CSF analogue, in elderly leukopenic patients, suggested that Leukine should be tested as a treatment to reverse cerebral amyloid pathology and cognitive impairment in AD patients. It was also implied that age-related depressed hematopoiesis may contribute to AD pathogenesis.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-02-01T21:57:42Z No. of bitstreams: 1 RodrigoGadelhaVasconcelos_TESE.pdf: 1777603 bytes, checksum: 142978c0b438c9eba25a0468ff97275f (MD5) / Approved for entry into archive by Elisangela Moura (lilaalves@gmail.com) on 2016-03-07T23:32:33Z (GMT) No. of bitstreams: 1 RodrigoGadelhaVasconcelos_TESE.pdf: 1777603 bytes, checksum: 142978c0b438c9eba25a0468ff97275f (MD5) / Made available in DSpace on 2016-03-07T23:32:33Z (GMT). No. of bitstreams: 1 RodrigoGadelhaVasconcelos_TESE.pdf: 1777603 bytes, checksum: 142978c0b438c9eba25a0468ff97275f (MD5) Previous issue date: 2014-12-18 / A les?o perif?rica de c?lulas gigantes (LPCG) e a les?o central de c?lulas gigantes (LCCG) s?o les?es histologicamente semelhantes que acometem a regi?o de cabe?a e pesco?o. O estudo teve a finalidade de analisar a express?o imuno-histoqu?mica atrav?s dos marcadores GLUT-1, GLUT-3 e M-CSF em uma s?rie de casos de les?o perif?rica e central de c?lulas gigantes, na tentativa de estabelecer poss?veis associa??es e correla??es entre a express?o destas prote?nas nessas les?es, buscando uma melhor compreens?o do diferente comportamento biol?gico dessas entidades patol?gicas. A amostra foi constitu?da por 20 esp?cimes teciduais emblocados em parafina de LPCG, 20 de LCCG n?o agressivo e 20 de LCCG agressivo, oriundos do Servi?o de Anatomia Patol?gica da Disciplina de Patologia Oral do Departamento de Odontologia da UFRN. Em rela??o ao GLUT-1, verificou-se uma diferen?a estatisticamente significante (p< 0,05) na quantidade de c?lulas mononucleares imunomarcadas entre a les?o perif?rica (LP) e a les?o central n?o agressiva (LCNA) e entre a LP e a les?o central agressiva (LCA). Em rela??o ? intensidade da marca??o tamb?m foi verificado uma diferen?a estatisticamente significante tanto para as c?lulas mononucleares quanto para as c?lulas gigantes entre LP e LCNA e entre LP e LCA, nas c?lulas gigantes tamb?m ocorreu uma diferen?a estatisticamente significante entre a LCNA e a LCA. Em rela??o ao GLUT-3, foi encontrada uma diferen?a estatisticamente significante entre LP e LCA e entre LCNA e LCA na quantidade de c?lulas mononucleares imunomarcadas. No que concerne ? intensidade de marca??o para a referida prote?na foi verificado uma diferen?a estatisticamente significante nas c?lulas gigantes entre LP e LCA. Para o M-CSF foi observado apenas uma diferen?a estatisticamente significante na intensidade de marca??o nas c?lulas mononucleares entre LP e LCNA e entre LP e LCA. Com base nestes resultados, pode-se concluir a participa??o do GLUT-1, GLUT-3 e do M-CSF na patog?nese das les?es estudadas. Os transportadores de glicose estariam envolvidos no fornecimento de energia, para o metabolismo energ?tico das c?lulas e a prote?na osteoclastog?nica estaria envolvida no mecanismo de reabsor??o ?ssea encontrada nessas les?es. / The peripheral giant cell lesion ( PG CL ) and the central giant cell lesion ( CGC L) are lesions histologically similar affecting the head and neck region . The study aimed to analyze the immunohistochemical expression of markers GLUT - 1 , GLUT - 3 and M - CSF in a series of cases of PGCL and CGCL , in trying to understand the different biological behavior of these pathologies . The sample consisted of 20 tissue specimens of PGCL 20 central lesion of not aggressive giant cell ( CLNAGC) and 20 central lesi on of aggressive giant cell ( CLAGC), coming from the Pathology Unit of Oral Pathology of the Department of Dentistry of UFRN . W as performed the s emi - quantitative and qualitative analysis of immunohistochemical expression of the markers in giant cells and m ononuclear cells . In relation to the GLUT - 1, it was found a statistically significant difference (p < 0.05) in the number of mononuclear cells immunomarked between the PGCL and the CLNAGC and between the PGCL and CLAGC . Regarding the intensity of staining w as also observed a statistically significant difference both at the mononuclear cells as in giant cells between PL and CLNAGC and between PGCL and CLAGC , at the giant cells there was also a statistically significant difference between the CLNAGC and CLAGC . In relation to GLUT - 3 , was found a statistically significant difference between PGCL and CLAGC and between CLAGC and CLNAGC in amount of mononuclear cells immunomarked . Regarding the intensity of labeling for such protein was found a statistically signifi cant difference at the giant cells between PL and CLAGC . To the M - CSF was observed only a statistically significant difference in the intensity of labeling at the mononuclear cells between PGCL and CLNAGC and between PGCL and CLAGC . Based on these results, we can conclude the participation of GLUT - 1, GLUT - 3 and M - CSF in the pathogenesis of the lesions studied. The bigger immunostaining of these proteins in mononuclear cells show that these cells perform a higher metabolic activity and osteoclastogenic, espe cially in CLAGC . It was found that the mononuclear cells were more related to the pathogenesis of the studied lesions than properly the giant s cell s.