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Dr Joaquin Castilla, Ikerbasque Research Professor, CIC bioGUNE - Proteomics unit (Prion lab). Parque tecnológico de Bizkaia. Derio 48160 (Bizkaia). Spain

Joaquin Castilla began working on Prions in 1998. He played a major role in developing Protein Misfolding Cyclic Amplification (PMCA), a technique comparable to PCR that amplifies prion proteins (PrP).

Summary

One of the characteristics of Prions is their ability to infect some species and not others. This phenomenon is known as the transmission barrier. In general, the transmission barrier is expressed by an incomplete attack rate and long incubation times which become shorter after serial inoculation passages. The absence of natural TSE cases and/or failed experimental transmissions has suggested that some species could be resistant for prion diseases.

Unfortunately, the molecular basis of the transmission barrier phenomenon is currently unknown and we cannot predict the degree of a species barrier simply by comparing the prion proteins from two species. We have conducted a series of experiments using the Protein Misfolding Cyclic Amplification (PMCA) technique that mimics in vitro some of the fundamental steps involved in prion replication in vivo albeit with accelerated kinetics. We have used this method to efficiently replicate a variety of prion strains from, among others, mice, hamsters, bank voles, deer, cattle, sheep and humans. The in vitro generated PrPres possess key prion features, i.e. they are infectious in vivo and maintain their strain specificity. We are using the PMCA to generate infectious PrPres from species hitherto considered to be resistant to prion disease and assay the role that certain amino acids play in the transmission barriers.

The correlation between in vivo data and our in vitro results suggest that PMCA is a valuable tool for studying the strength of the transmission barriers between diverse species and for evaluating the potential risks of the newly generated prion species to humans and animals.

Recent Publications:

Angers RC, Kang HE, Napier D, Browning S, Seward T, Mathiason C, Balachandran A, McKenzie D, Castilla J, Soto C, Jewell J, Graham C, Hoover EA, Telling GC.
Prion strain mutation determined by prion protein conformational compatibility and primary structure
Science. 2010 May 28;328(5982):1154-8.

Morales R, Estrada LD, Diaz-Espinoza R, Morales-Scheihing D, Jara MC, Castilla J, Soto C.
Molecular crosstalk between misfolded proteins in animal models of Alzheimer’s and prion diseases.
J Neurosci. 2010 Mar 31;30(13):4528-35.

Castilla J, Morales R, Saá P, Soto C.
Propagation of prion strains in vitro.
EMBO J. 27, 2557-2566; 2008.

Castilla J, Gonzaléz D, Saá P, Morales R, de Castro J, Soto C.
Crossing species barrier by in vitro replication of protein misfolding generates new infectious prions.
Cell. 134, 757-768; 2008.

Green KM, Castilla J, Seward TS, Napier DL, Jewell JE, Soto C, Telling GC.
Accelerated High Fidelity Prion Amplification Within and Across Prion Species Barriers.
PLOS Pathogens. 4, 1-12; 2008.

Saá P, Castilla J, Soto C.
Pre-symptomatic detection of prions in blood.
Science. 313, 92-4; 2006.

Soto C, Estrada L, Castilla J.
Amyloids, prions and the inherent infectious nature of misfolded protein aggregates.
Trends in Biochemical Sciences. 31, 150-155; 2006.

Castilla J, Saá P, Soto C.
Detection of prions in blood.
Nat. Med. 11, 982-985; 2005.

Castilla J, Saá P, Hetz C, Soto C.
In Vitro Generation of Infectious Scrapie Prions.
Cell. 121, 195-206; 2005.

Soto C, Castilla J.
The controversial protein-only hypothesis of prion propagation.
Nat Med. 10, S63-S67; 2004.

For more information:http://www.cicbiogune.es/secciones/investigacion/ficha_laboratorio.php?idioma=en&unidad=2&subgrupo=52