scholarly journals Lentivirus Infection in the Brain Induces Matrix Metalloproteinase Expression: Role of Envelope Diversity

2000 ◽  
Vol 74 (16) ◽  
pp. 7211-7220 ◽  
Author(s):  
J. B. Johnston ◽  
Y. Jiang ◽  
G. van Marle ◽  
M. B. Mayne ◽  
W. Ni ◽  
...  

ABSTRACT Infection of the brain by lentiviruses, including human immunodeficiency virus (HIV) and feline immunodeficiency virus (FIV), causes inflammation and results in neurodegeneration. Molecular diversity within the lentivirus envelope gene has been implicated in the regulation of cell tropism and the host response to infection. Here, we examine the hypothesis that envelope sequence diversity modulates the expression of host molecules implicated in lentivirus-induced brain disease, including matrix metalloproteinases (MMP) and related transcription factors. Infection of primary macrophages by chimeric HIV clones containing brain-derived envelope fragments from patients with HIV-associated dementia (HAD) or nondemented AIDS patients (HIV-ND) showed that MMP-2 and -9 levels in conditioned media were significantly higher for the HAD clones. Similarly, STAT-1 and JAK-1 levels were higher in macrophages infected by HAD clones. Infections of primary feline macrophages by the neurovirulent FIV strain (V1CSF), the less neurovirulent strain (Petaluma), and a chimera containing the V1CSF envelope in a Petaluma background (FIV-Ch) revealed that MMP-2 and -9 levels were significantly higher in conditioned media from V1CSF- and FIV-Ch-infected macrophages, which was associated with increased intracellular STAT-1 and JAK-1 levels. The STAT-1 inhibitor fludarabine significantly reduced MMP-2 expression, but not MMP-9 expression, in FIV-infected macrophages. Analysis of MMP mRNA and protein levels in brain samples from HIV-infected persons or FIV-infected cats showed that MMP-2 and -9 levels were significantly increased in lentivirus-infected brains compared to those of uninfected controls. Elevated MMP expression was accompanied by significant increases in STAT-1 and JAK-1 mRNA and protein levels in the same brain samples. The present findings indicate that two lentiviruses, HIV and FIV, have common mechanisms of MMP-2 and -9 induction, which is modulated in part by envelope sequence diversity and the STAT-1/JAK-1 signaling pathway.

2002 ◽  
Vol 76 (8) ◽  
pp. 3626-3636 ◽  
Author(s):  
J. B. Johnston ◽  
C. Power

ABSTRACT The use of chemokine receptors as cell recognition signals is a property common to several lentiviruses, including feline, human, and simian immunodeficiency viruses. Previously, two feline immunodeficiency virus (FIV) isolates, V1CSF and Petaluma, were shown to use chemokine receptors in a strain-dependent manner to infect human peripheral blood mononuclear cells (PBMC) (J. Johnston and C. Power, J. Virol. 73:2491-2498, 1999). Since the sequences of these viruses differed primarily in regions of the FIV envelope gene implicated in receptor use and cell tropism, envelope chimeras of V1CSF and Petaluma were constructed to investigate the role of envelope diversity in the profiles of chemokine receptors used by FIV to infect primate cells. By use of a receptor-blocking assay, all viruses were found to infect human and macaque PBMC through a mechanism involving the CXCR4 receptor. However, infection by viruses encoding the V3-to-V5 region of the V1CSF surface unit was also inhibited by blockade of the CCR3 or CCR5 receptor. Similar results were obtained with GHOST cells, human osteosarcoma cells expressing specific combinations of chemokine receptors. CXCR4 was required for infection by all FIV strains, but viruses expressing the V3-to-V5 region of V1CSF required the concurrent presence of either CCR3 or CCR5. In contrast, CXCR4 alone was sufficient to allow infection of GHOST cells by FIV strains possessing the V3-to-V5 region of Petaluma. To assess the role of primate chemokine receptors in productive infection, Crandell feline kidney (CrFK) cells that expressed human CXCR4, CCR3, or CCR5 in addition to feline CXCR4 were generated. Sustained infection by viruses encoding the V3-to-V5 region of V1CSF was detected in CrFK cells expressing human CCR3 or CCR5 but not in cells expressing CXCR4 alone, while all CrFK cell lines were permissive to viruses encoding the V3-to-V5 region of Petaluma. These results indicate that FIV uses chemokine receptors to infect both human and nonhuman primate cells and that the profiles of these receptors are dependent on envelope sequence, and they provide insights into the mechanism by which xenoinfections may occur.


2021 ◽  
Vol 22 (16) ◽  
pp. 8876
Author(s):  
Pierre Layrolle ◽  
Pierre Payoux ◽  
Stéphane Chavanas

Peroxisome Proliferator-Activated Receptor gamma (PPARγ) is a master regulator of metabolism, adipogenesis, inflammation and cell cycle, and it has been extensively studied in the brain in relation to inflammation or neurodegeneration. Little is known however about its role in viral infections of the brain parenchyma, although they represent the most frequent cause of encephalitis and are a major threat for the developing brain. Specific to viral infections is the ability to subvert signaling pathways of the host cell to ensure virus replication and spreading, as deleterious as the consequences may be for the host. In this respect, the pleiotropic role of PPARγ makes it a critical target of infection. This review aims to provide an update on the role of PPARγ in viral infections of the brain. Recent studies have highlighted the involvement of PPARγ in brain or neural cells infected by immunodeficiency virus 1, Zika virus, or human cytomegalovirus. They have provided a better understanding on PPARγ functions in the infected brain, and revealed that it can be a double-edged sword with respect to inflammation, viral replication, or neuronogenesis. They unraveled new roles of PPARγ in health and disease and could possibly help designing new therapeutic strategies.


Development ◽  
2001 ◽  
Vol 128 (23) ◽  
pp. 4881-4890 ◽  
Author(s):  
Carole Mathis ◽  
Natalia Denisenko-Nehrbass ◽  
Jean-Antoine Girault ◽  
Emiliana Borrelli

The membrane of myelinated axons is divided into functionally distinct domains characterized by the enrichment of specific proteins. The mechanisms responsible for this organization have not been fully identified. To further address the role of oligodendrocytes in the functional segmentation of the axolemma in vivo, the distribution of nodal (Na+ channels, ankyrin G), paranodal (paranodin/contactin-associated-protein) and juxtaparanodal (Kv1.1 K+ channels) axonal markers, was studied in the brain of MBP-TK and jimpy mice. In MBP-TK transgenic mice, oligodendrocyte ablation was selectively induced by FIAU treatment before and during the onset of myelination. In jimpy mice, oligodendrocytes degenerate spontaneously within the first postnatal weeks after the onset of myelination. Interestingly, in MBP-TK mice treated for 1-20 days with FIAU, despite the ablation of more than 95% of oligodendrocytes, the protein levels of all tested nodal markers was unaltered. Nevertheless, these proteins failed to cluster in the nodal regions. By contrast, in jimpy mice, despite a diffused localization of paranodin, the formation of nodal clusters of Na+ channels and ankyrin G was observed. Furthermore, K+ channels clusters were transiently visible, but were in direct contact with nodal markers. These results demonstrate that the organization of functional domains in myelinated axons is oligodendrocyte dependent. They also show that the presence of these cells is a requirement for the maintenance of nodal and paranodal regions.


2013 ◽  
Vol 65 (1) ◽  
pp. 255-264
Author(s):  
Natasa Loncarevic-Vasiljkovic ◽  
Vesna Pesic ◽  
N. Tanic ◽  
Desanka Milanovic ◽  
Aleksandra Mladenovic-Djordjevic ◽  
...  

The recovery period following cortical injury (CI) is characterized by a dynamic and highly complex interplay between beneficial and detrimental events. The aim of this study was to examine the expressions of Glial Fibrillary Acidic Protein (GFAP), Apolipoprotein E (ApoE) and Amyloid Precursor Protein (APP), all of which are involved in brain plasticity and neurodegeneration. Our results reveal that CI strongly influenced GFAP, ApoE and APP mRNA expression, as well as GFAP and ApoE protein expression. Considering the pivotal role of these proteins in the brain, the obtained results point to their potential contribution in neurodegeneration and consequent Alzheimer?s disease development.


1999 ◽  
Vol 73 (4) ◽  
pp. 2596-2603 ◽  
Author(s):  
Gregg A. Dean ◽  
Sunee Himathongkham ◽  
Ellen E. Sparger

ABSTRACT Independent studies have demonstrated different cell tropisms for molecular clones of feline immunodeficiency virus (FIV). In this report, we examined three clones, FIV-pF34, FIV-14, and FIV-pPPR, for replication in Crandell feline kidney (CrFK) cells, feline peripheral blood mononuclear cells (PBMC), and feline macrophage cultures. Importantly, cell tropism for these three clones was also examined in vivo. FIV-pF34 replication was efficient in CrFK cells but severely restricted in PBMC, whereas replication of FIV-pPPR was vigorous in PBMC but severely restricted in CrFK cells. FIV-14 replication was productive in both CrFK cells and PBMC. Interestingly, all three molecular clones replicated with similar efficiencies in primary feline monocyte-derived macrophages. In vivo, FIV-pF34 proved least efficient for establishing persistent infection, and proviral DNA when detectable, was localized predominately to nonlymphoid cell populations (macrophages). FIV-pPPR proved most efficient for induction of a persistent viremia in vivo, and proviral DNA was localized predominately in CD4+ and CD8+ lymphocyte subsets. FIV-14 inoculation of cats resulted in an infection characterized by seroconversion and localization of proviral DNA in CD4+ lymphocytes only. Results of this study on diverse FIV molecular clones revealed that in vitro replication efficiency of an FIV isolate in PBMC directly correlated with replication efficiency in vivo, whereas proficiency for replication in macrophages in vitro was not predictive for replication potential in vivo. Also, infection of both CD4+ and CD8+ lymphocyte subsets was associated with higher virus load in vivo. Results of the studies on these three FIV clones, which exhibited differential cell tropism, indicated a correlation between in vitro and in vivo cell tropism and virus replication.


Cells ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2485
Author(s):  
Stephanie Sanders ◽  
Denise M. Herpai ◽  
Analiz Rodriguez ◽  
Yue Huang ◽  
Jeff Chou ◽  
...  

Glioblastoma (GBM) is the most aggressive malignant glioma. Therapeutic targeting of GBM is made more difficult due to its heterogeneity, resistance to treatment, and diffuse infiltration into the brain parenchyma. Better understanding of the tumor microenvironment should aid in finding more effective management of GBM. GBM-associated macrophages (GAM) comprise up to 30% of the GBM microenvironment. Therefore, exploration of GAM activity/function and their specific markers are important for developing new therapeutic agents. In this study, we identified and evaluated the expression of ALDH1A2 in the GBM microenvironment, and especially in M2 GAM, though it is also expressed in reactive astrocytes and multinucleated tumor cells. We demonstrated that M2 GAM highly express ALDH1A2 when compared to other ALDH1 family proteins. Additionally, GBM samples showed higher expression of ALDH1A2 when compared to low-grade gliomas (LGG), and this expression was increased upon tumor recurrence both at the gene and protein levels. We demonstrated that the enzymatic product of ALDH1A2, retinoic acid (RA), modulated the expression and activity of MMP-2 and MMP-9 in macrophages, but not in GBM tumor cells. Thus, the expression of ALDH1A2 may promote the progressive phenotype of GBM.


1999 ◽  
Vol 80 (10) ◽  
pp. 2639-2646 ◽  
Author(s):  
Thomas W. Vahlenkamp ◽  
Anthony De Ronde ◽  
Nancy N. M. P. Schuurman ◽  
Arno L. W. van Vliet ◽  
Judith van Drunen ◽  
...  

The envelope is of cardinal importance for the entry of feline immunodeficiency virus (FIV) into its host cells, which consist of cells of the immune system including macrophages. To characterize the envelope glycoprotein determinants involved in macrophage tropism, chimeric infectious molecular clones were constructed containing envelope gene sequences from isolates that had been propagated in peripheral blood mononuclear cells (PBMC). The progeny virus was examined for growth in PBMC and bone marrow-derived macrophages and viruses with different replication kinetics in macrophages were selected. Envelope-chimeric viruses revealed that nucleotide sequences encoding variable regions 3 and 4 of the surface glycoprotein, SU, are involved in macrophage tropism of FIV. To assess the biological importance of this finding, the phenotypes of envelope proteins of viruses derived from bone marrow, brain, lymph node and PBMC of an experimentally FIV-infected, healthy cat were examined. Since selection during propagation had to be avoided, provirus envelope gene sequences were amplified directly and cloned into an infectious molecular clone of FIV strain Petaluma. The viruses obtained were examined for their replication properties. Of 15 clones tested, 13 clones replicated both in PBMC and macrophages, two (brain-derived clones) replicated in PBMC only and none replicated in Crandell feline kidney cells or astrocytes. These results indicate that dual tropism for PBMC and macrophages is a common feature of FIV variants present in vivo.


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