Impaired B cells survival upon production of inflammatory cytokines by HIV-1 exposed follicular dendritic cells.

Background: Follicular dendritic cells (FDCs) are important components in the organization of germinal centers in lymphoid tissue where, following antigen presentation, B cells differentiate into memory B cells. The possibility of establishing primary cell lines from FDCs isolated from lymphoid tissue paved the way for characterization of FDC biological properties. We exposed primary FDC cell lines to HIV-1 strains in vitro and studied changes in the chemo-attractive properties of FDCs and release of inflammatory cytokines.

Cytotoxic T-lymphocytes secrete soluble factors that induce caspase-mediated apoptosis in glioblastoma cell lines.

We have previously shown that factors secreted by activated CTLs induce apoptosis in a panel of glioblastoma lines. In this study, we analyzed the expression of death receptors, activation of caspases and mRNA expression of 96 apoptotic genes in glioblastoma lines either sensitive or resistant to supernatant of activated CTLs. Our results indicate that exposure to supernatant triggers several pathways of caspase activation in glioblastoma lines involved in the initiation of both extrinsic and intrinsic apoptosis.

Long-lasting depression-like behavior and epigenetic changes of BDNF gene expression induced by perinatal exposure to methylmercury.

Substantial evidence indicates that predisposition to diseases can be acquired during early stages of development and interactions between environmental and genetic factors may be implicated in the onset of many pathological conditions. Data collected over several decades have shown that chemicals are among the relevant factors that can endanger CNS. We previously showed that perinatal exposure to methylmercury (MeHg) causes persistent changes in learning and motivational behavior in mice.

Host strain-dependent difference in susceptibility in a rat model of herpes simplex type 1 encephalitis.

Herpes simplex encephalitis (HSE) is characterized by severe focal brain inflammation leading to substantial loss of nervous tissue. The authors established a model of Herpes simplex virus type 1 (HSV)-1-induced acute encephalitis in the rat by injecting into the whiskers' area a virus strain isolated from a fatal human HSE case. The model might resemble natural propagation of HSV-1 in humans; spreading from the mouth and lips via the trigeminal nerve to trigeminal ganglia and subsequently entering the central nervous system (CNS).

Mitochondrial-mediated apoptosis in neural stem cells exposed to manganese.

Manganese is an essential nutrient for humans that has to be maintained at proper levels for normal brain functioning. However, manganese also acts as a toxicant to the brain, and several studies have linked exposure to excessive manganese to neurotoxicity in adults. A recent report has suggested that ingesting high doses of manganese via drinking water can impede intellectual functions in children.

Modulation of sFas indicates apoptosis in human herpes simplex encephalitis.

Herpes simplex encephalitis (HSE) is the most common cause of non-epidemic, acute and fatal viral encephalitis. A pronounced mortality and morbidity remains in HSE despite antiviral treatment. There is evidence of a vigorous intrathecal immune activity in acute phases of HSE and of persistently increased activity at follow-ups after years.

Soluble factors released by virus specific activated cytotoxic T-lymphocytes induce apoptotic death of astroglioma cell lines.

Astrocytomas and astrogliomas represent the most common types of primary tumors in human central nervous system and are associated with high mortality due to the absence of efficient therapy. Here we demonstrate that, upon antigen-specific activation, cytotoxic T-lymphocytes (CTLs) secrete products that inhibit proliferation and induce apoptosis in a significant proportion of astroglioma cell lines. This effect is tumor specific in that normal cultured astrocytes do not develop apoptotic changes upon exposure to supernatant of activated CTLs.

Astrocyte activation and apoptosis: their roles in the neuropathology of HIV infection.

Astrogliosis is a common neuropathological finding in the brains of HIV infected individuals; both activation and apoptosis of astrocytes are seen. This review aims to discuss the Fas pathway in the context of proliferation and apoptosis of astrocytes during HIV infection, and as a result of astrogliosis, the dysregulation of astrocyte-neuron networks. The presence of molecules reflecting astrocyte activation, which are derived from the solubilization of receptor/ligand from the surface of proliferating astrocytes, in the cerebrospinal fluid may be used to evaluate the degree of brain cell activation during HAART therapy.