Computer-aided scoring of () gene amplification status in breast cancer.

Background: Identification of HER2 protein overexpression and/or amplification of the gene are required to qualify breast cancer patients for HER2 targeted therapies. hybridization (ISH) assays that identify gene amplification function as a stand-alone test for determination of HER2 status and rely on the manual quantification of the number of genes and copies of chromosome 17 to determine amplification.

Methods: To assist pathologists, we have developed the uPath HER2 Dual ISH Image Analysis for Breast (uPath HER2 DISH IA) algorithm, as an adjunctive aid in the determination of gene status in breast cancer specimens.

The transcriptome of HIV-1 infected intestinal CD4+ T cells exposed to enteric bacteria.

Global transcriptome studies can help pinpoint key cellular pathways exploited by viruses to replicate and cause pathogenesis. Previous data showed that laboratory-adapted HIV-1 triggers significant gene expression changes in CD4+ T cell lines and mitogen-activated CD4+ T cells from peripheral blood. However, HIV-1 primarily targets mucosal compartments during acute infection in vivo.

Genistein interferes with SDF-1- and HIV-mediated actin dynamics and inhibits HIV infection of resting CD4 T cells.

Background: Binding of HIV to the chemokine coreceptor CXCR4 mediates viral fusion and signal transduction that promotes actin dynamics critical for HIV infection of blood resting CD4 T cells. It has been suggested that this gp120-mediated actin activity resembles the chemotactic actin dynamics mediated by chemokines such as SDF-1. To determine whether inhibiting SDF-1-mediated chemotactic activity can also inhibit HIV infection, we screened several inhibitors known to reduce SDF-1-mediated chemotaxis of T cells.

LIM kinase 1 modulates cortical actin and CXCR4 cycling and is activated by HIV-1 to initiate viral infection.

Almost all viral pathogens utilize a cytoskeleton for their entry and intracellular transport. In HIV-1 infection, binding of the virus to blood resting CD4 T cells initiates a temporal course of cortical actin polymerization and depolymerization, a process mimicking the chemotactic response initiated from chemokine receptors. The actin depolymerization has been suggested to promote viral intracellular migration through cofilin-mediated actin treadmilling.

Effects of microtubule modulators on HIV-1 infection of transformed and resting CD4 T cells.

Previous studies have observed fluorescently labeled HIV particles tracking along microtubule networks for nuclear localization. To provide direct evidence for the involvement of microtubules in early steps of HIV infection of human CD4 T cells, we used multiple microtubule modulators such as paclitaxel (originally called taxol; 1 μM), vinblastine (1 and 10 μM), colchicine (10 and 100 μM), and nocodazole (10 and 100 μM) to disturb microtubule networks in transformed and resting CD4 T cells. Although these drugs disrupted microtubule integrity, almost no inhibition of HIV-1 infection was observed.

Chemokine coreceptor signaling in HIV-1 infection and pathogenesis.

Binding of the HIV-1 envelope to its chemokine coreceptors mediates two major biological events: membrane fusion and signaling transduction. The fusion process has been well studied, yet the role of chemokine coreceptor signaling in viral infection has remained elusive through the past decade. With the recent demonstration of the signaling requirement for HIV latent infection of resting CD4 T cells, the issue of coreceptor signaling needs to be thoroughly revisited.

The HIV envelope but not VSV glycoprotein is capable of mediating HIV latent infection of resting CD4 T cells.

HIV fusion and entry into CD4 T cells are mediated by two receptors, CD4 and CXCR4. This receptor requirement can be abrogated by pseudotyping the virion with the vesicular stomatitis virus glycoprotein (VSV-G) that mediates viral entry through endocytosis. The VSV-G-pseudotyped HIV is highly infectious for transformed cells, although the virus circumvents the viral receptors and the actin cortex.

Cofilin activation in peripheral CD4 T cells of HIV-1 infected patients: a pilot study.

Cofilin is an actin-depolymerizing factor that regulates actin dynamics critical for T cell migration and T cell activation. In unstimulated resting CD4 T cells, cofilin exists largely as a phosphorylated inactive form. Previously, we demonstrated that during HIV-1 infection of resting CD4 T cells, the viral envelope-CXCR4 signaling activates cofilin to overcome the static cortical actin restriction.

HIV envelope-CXCR4 signaling activates cofilin to overcome cortical actin restriction in resting CD4 T cells.

Binding of the HIV envelope to the chemokine coreceptors triggers membrane fusion and signal transduction. The fusion process has been well characterized, yet the role of coreceptor signaling remains elusive. Here, we describe a critical function of the chemokine coreceptor signaling in facilitating HIV infection of resting CD4 T cells.

T cell infiltration is associated with increased Lyme arthritis in TLR2-/- mice.

C57BL/6 mice deficient in TLR2 develop more severe arthritis following infection with Borrelia burgdorferi than do wild-type C57BL/6 mice, and this increase is suppressed by the simultaneous presence of the scid mutation. This suggested a requirement for lymphocytes in the development of subacute Lyme arthritis in TLR2(-/-) mice, a feature not commonly associated with this arthritis. The increased pathology of B.

Tripalmitoyl-S-glyceryl-cysteine-dependent OspA vaccination of toll-like receptor 2-deficient mice results in effective protection from Borrelia burgdorferi challenge.

Toll-like receptor 2 (TLR2) is a transmembrane signal transducer for tripalmitoyl-S-glyceryl-cysteine (Pam(3)Cys)-modified lipoproteins, including OspA from the Lyme disease spirochete Borrelia burgdorferi. The Pam(3)Cys modification provides adjuvant activity for inducing humoral responses, suggesting that TLR2 could function as the adjuvant receptor for the OspA vaccine. The importance of TLR2 in the humoral response to OspA was confirmed, because overall levels of immunoglobulin G (IgG) were reduced in TLR2-deficient mice, when compared with those in wild-type mice.

Toll-like receptor 2 is required for innate, but not acquired, host defense to Borrelia burgdorferi.

Borrelia burgdorferi lipoproteins activate inflammatory cells through Toll-like receptor 2 (TLR2), suggesting that TLR2 could play a pivotal role in the host response to B. burgdorferi. TLR2 does play a critical role in host defense, as infected TLR2(-/-) mice harbored up to 100-fold more spirochetes in tissues than did TLR2(+/+) littermates.