抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Statistical method for testing the neutral mutation hypothesis by DNA polymorphism.

MicroRNAs (miRNAs) are small non-coding RNAs that function as guide molecules in RNA silencing. Targeting most protein-coding transcripts, miRNAs are involved in nearly all developmental and pathological processes in animals. The biogenesis of miRNAs is under tight temporal and spatial control, and their dysregulation is associated with many human diseases, particularly cancer. In animals, miRNAs are ∼22 nucleotides in length, and they are produced by two RNase III proteins--Drosha and Dicer. miRNA biogenesis is regulated at multiple levels, including at the level of miRNA transcription; its processing by Drosha and Dicer in the nucleus and cytoplasm, respectively; its modification by RNA editing, RNA methylation, uridylation and adenylation; Argonaute loading; and RNA decay. Non-canonical pathways for miRNA biogenesis, including those that are independent of Drosha or Dicer, are also emerging.

Regulation of microRNA biogenesis

To realize the therapeutic potential of RNA drugs, efficient, tissue-specific and nonimmunogenic delivery technologies must be developed. Here we show that exosomes-endogenous nano-vesicles that transport RNAs and proteins-can deliver short interfering (si)RNA to the brain in mice. To reduce immunogenicity, we used self-derived dendritic cells for exosome production. Targeting was achieved by engineering the dendritic cells to express Lamp2b, an exosomal membrane protein, fused to the neuron-specific RVG peptide. Purified exosomes were loaded with exogenous siRNA by electroporation. Intravenously injected RVG-targeted exosomes delivered GAPDH siRNA specifically to neurons, microglia, oligodendrocytes in the brain, resulting in a specific gene knockdown. Pre-exposure to RVG exosomes did not attenuate knockdown, and non-specific uptake in other tissues was not observed. The therapeutic potential of exosome-mediated siRNA delivery was demonstrated by the strong mRNA (60%) and protein (62%) knockdown of BACE1, a therapeutic target in Alzheimer's disease, in wild-type mice.

Delivery of siRNA to the mouse brain by systemic injection of targeted exosomes

Small RNAs of 20-30 nucleotides can target both chromatin and transcripts, and thereby keep both the genome and the transcriptome under extensive surveillance. Recent progress in high-throughput sequencing has uncovered an astounding landscape of small RNAs in eukaryotic cells. Various small RNAs of distinctive characteristics have been found and can be classified into three classes based on their biogenesis mechanism and the type of Argonaute protein that they are associated with: microRNAs (miRNAs), endogenous small interfering RNAs (endo-siRNAs or esiRNAs) and Piwi-interacting RNAs (piRNAs). This Review summarizes our current knowledge of how these intriguing molecules are generated in animal cells.

/pdf/biogenesis-of-small-rnas-in-animals-1m2f3gqoz1.pdf

Biogenesis of small RNAs in animals.

P 1 Caco-2 cells as an in vitro model for adenoviral gene transfer to the gut epithelium

717. RNAi Therapy for Dominant Neurodegenerative Diseases

The present invention provides compounds useful for the detection of the enzyme tripeptidyl protease I (TPP-1). The invention also provides methods of making such compounds, methods of using such compounds, and kits and compositions containing such compounds. In one embodiment, Gly-L-Pro-L-Ser-1-anthraquinonylhydrazide, in combination with p-anisaldehyde, is used to detect TPP-1.

Compounds and methods for detecting tripeptidyl protease I

http://deepblue.lib.umich.edu/bitstream/handle/2027.42/31002/0000677.pdf?sequence=1

Synthesis of normal and variant human hypoxanthine-guanine phosphoribosyltransferase in Escherichia coli

Provided are methods of treating a lysosomal storage disorder in a mammal which method includes administering AAV particles encoding a polypeptide to the central nervous system of the mammal AAV particles may be delivered by direct injection into the brain, spinal cord, cerebral spinal fluid or a portion thereof for expression

Beverly L. Davidson

Papers

P 1 Caco-2 cells as an in vitro model for adenoviral gene transfer to the gut epithelium

717. RNAi Therapy for Dominant Neurodegenerative Diseases

Compounds and methods for detecting tripeptidyl protease I

Synthesis of normal and variant human hypoxanthine-guanine phosphoribosyltransferase in Escherichia coli

Gene transfer compositions, methods and uses for treating neurodegenerative diseases