Methods for mechanical delivery of viral vectors into rhesus monkey brain.

BACKGROUND: Modern molecular tools make it possible to manipulate neural activity in a reversible and cell-type specific manner. For rhesus monkey research, molecular tools are generally introduced via viral vectors. New instruments designed specifically for use in monkey research are needed to enhance the efficiency and reliability of vector delivery. NEW METHOD: A suite of multi-channel injection devices was developed to permit efficient and uniform vector delivery to cortical regions of the monkey brain. Manganese was co-infused with virus to allow rapid post-surgical confirmation of targeting accuracy using MRI. A needle guide was designed to increase the accuracy of sub-cortical targeting using stereotaxic co-ordinates. RESULTS: The multi-channel injection devices produced dense, uniform coverage of dorsal surface cortex, ventral surface cortex, and intra-sulcal cortex, respectively. Co-infusion of manganese with the viral vector allowed for immediate verification of injection accuracy. The needle guide improved accuracy of targeting sub-cortical structures by preventing needle deflection. COMPARISON WITH EXISTING METHOD(S): The current methods, hand-held injections or single slow mechanical injection, for surface cortex transduction do not, in our hands, produce the density and uniformity of coverage provided by the injector arrays and associated infusion protocol. CONCLUSIONS: The efficiency and reliability of vector delivery has been considerably improved by the development of new methods and instruments. This development should facilitate the translation of chemo- and optogenetic studies performed in smaller animals to larger animals such as rhesus monkeys.

HIV Nef increases T cell ERK MAP kinase activity.

The human immunodeficiency regulatory protein Nef enhances viral replication and is central to viral pathogenesis. Although Nef has displayed a capacity to associate with a diverse assortment of cellular molecules and to increase T cell activity, the biochemical activity of Nef in T cells remains poorly defined. In this report we examine the bioactivity of Nef in primary CD4 T cells and, in particular, focus on the biochemical pathways known to be central to T cell activity. The extracellular signal-regulated kinase (ERK) mitogen-activated protein (MAP) kinase pathway was dramatically affected by Nef expression with increases in ERK, MEK, and Elk induction. The capacity of Nef to increase the MAP kinase pathway activity was dependent on T cell receptor stimulation. By increasing ERK MAP kinase activity, Nef is functionally associated with a kinase known to affect T cell activity, viral replication, and viral infectivity.