BRANFORD, Conn.--(Business Wire)--
A study published this month in the journal Tissue Antigens reports that
researchers at Roche Molecular Systems (SWX:RO) (SWX:ROG) (Pink Sheets: RHHBY)
in Pleasanton, CA have used high-throughput sequencing technology from 454 Life
Sciences, a Roche Company, to carry out high-resolution human leukocyte antigen
(HLA) genotyping in research samples. In the study, the researchers performed
ultra-deep amplicon sequencing of specific HLA class I and II gene loci with the
Genome Sequencer FLX System and successfully assigned allele-level genotypes
using software developed by Conexio Genomics. The results of the study have
important implications for future research on a wide variety of human diseases
and tissue transplantation.
HLA class I and class II genes play a critical role in the adaptive immune
response. Importantly, they encode for the cell-surface proteins responsible for
differentiating between self, non-self cells and other antigens. For example,
accurate HLA genotyping is clinically important for hematopoetic stem cell (HSC)
transplantation between unrelated donors and recipients to minimize the risk of
graft rejection and graft versus host disease (GVHD). Accurate HLA genotyping is
also critically important for research on many human diseases. "Specific alleles
and haplotypes at the class I and class II loci are strongly associated with a
variety of autoimmune disease as well as some cancers and infectious diseases,"
explained Henry Erlich study author and Director of the Department of Human
Genetics at Roche Molecular Systems. "High resolution, high throughput HLA
typing will be very valuable in these large research association studies."
Accurate HLA genotyping is complicated by the highly polymorphic nature of this
genomic region. There are hundreds of different allele sequences at the various
HLA class I and class II genes. Current methods, based on Sanger-sequencing
technology, are limited in their ability to resolve "phase ambiguities" which
occurs commonly when an individual is heterozygous at many positions that are
very close to one another.
"The challenge is to determine which polymorphic sequences go together on which
alleles," explained Erlich. "In our research, we were able to successfully
assign allele-level HLA genotypes at eight loci in 48 individual samples from
the data produced in a single Genome Sequencer FLX System run. The abundance of
long sequencing reads allowed us to unambiguously assign HLA alleles in a much
faster and more cost efficient manner than with traditional technologies. We
were also able to detect rare variants, such as the non-transmitted maternal
allele in a SCIDS [Severe Combined Immunodeficiency Syndrome] sample, reflecting
the presence of maternal cells in the subject`s circulation."
This month, 454 Life Sciences will launch the latest GS FLX Titanium kits and
software, offering increases in read length and throughput for amplicon
sequencing. The new kits will improve targeting resequencing studies, such as
HLA class I and II genotyping, by more completely covering loci with fewer
amplicons and enhancing sensitivity for identifying rare variants and
haplotypes. "Our early work with the GS FLX Titanium amplicon sequencing kits
have demonstrated that we can now type more individuals per run and more exons
per amplification reaction," says Erlich.
"As proven by this study, 454 Sequencing Systems provides a cost-effective and
reliable alternative to current research methods for HLA typing," said
Christopher McLeod, President and CEO of 454 Life Sciences. "This will only
improve with the longer read lengths available in our latest series of GS FLX
Titanium kits and software."
For more information on 454 Sequencing Systems, visit www.454.com.
About Roche
Headquartered in Basel, Switzerland, Roche is one of the world`s leading
research-focused healthcare groups in the fields of pharmaceuticals and
diagnostics. As the world`s biggest biotech company and an innovator of products
and services for the early detection, prevention, diagnosis and treatment of
diseases, the Group contributes on a broad range of fronts to improving people`s
health and quality of life. Roche is the world leader in in-vitro diagnostics
and drugs for cancer and transplantation, and is a market leader in virology. It
is also active in other major therapeutic areas such as autoimmune diseases,
inflammatory and metabolic disorders and diseases of the central nervous system.
In 2008 sales by the Pharmaceuticals Division totalled 36.0 billion Swiss
francs, and the Diagnostics Division posted sales of 9.7 billion francs. Roche
has R&D agreements and strategic alliances with numerous partners, including
majority ownership interests in Genentech and Chugai, and invested nearly 9
billion Swiss francs in R&D in 2008. Worldwide, the Group employs about 80,000
people. Additional information is available on the Internet at www.roche.com.
Bentley et al. High-resolution, high-throughput HLA genotyping by
next-generation sequencing. (2009) Tissue Antigens.
The 454 GS FLX System is sold for life science research use only.
454, 454 SEQUENCING, 454 LIFE SCIENCES and GS FLX TITANIUM are trademarks of
Roche.
Roche Diagnostics
Dr. Burkhard Ziebolz
Phone: +49 8856 604830
Email: burkhard.ziebolz@roche.com
or
454 Life Sciences Corporation, a Roche company
Dr. Ulrich Schwoerer
Phone: 203-871-2300
Email: ulrich.schwoerer@roche.com
Copyright Business Wire 2009
