{"id":343,"date":"2012-02-12T17:24:45","date_gmt":"2012-02-12T22:24:45","guid":{"rendered":"http:\/\/carlyhodes.com\/?p=343"},"modified":"2012-02-12T17:24:45","modified_gmt":"2012-02-12T22:24:45","slug":"reverse-genetics-better-vaccines","status":"publish","type":"post","link":"https:\/\/carlyhodes.com\/?p=343","title":{"rendered":"Reverse genetics better vaccines"},"content":{"rendered":"

Cornell-Israel collaboration works backwards to <\/strong>fight virus threatening livestock trade worldwide<\/strong><\/p>\n

European livestock beware: bluetongue virus is coming your way, and it\u2019s deadlier than ever. Once limited to warmer climes, the insect-borne virus\u2019s new highly pathogenic strain has been spreading northward since 2006, reaching farther into Europe than ever before. Bluetongue\u2019s rise threatens ruminants and the industries depending on them. Sheep and deer suffer most, developing dangerously high fevers, swollen mouths, and occasionally the disease\u2019s signature blue tongue. Most infected sheep and deer die; other ruminants (cattle, goats, camels, buffalo, and antelopes) show milder symptoms but can carry the disease, further enabling its spread.<\/p>\n

\"\"<\/a><\/p>\n

Illnesses, deaths, and international trade restrictions due to bluetongue have cost the world economy billions, including the United States, whose more benign strains still hinder livestock-related exports to bluetongue-free countries. Vaccines work weakly at best: with 25 separate strains each needing yearly updates, the quickly-evolving bluetongue virus seems to defy defense.<\/p>\n

In the arms race between virus and victim, human knowledge is catching up. Dr. John Parker, virologist at Cornell University College of Veterinary Medicine\u2019s Baker Institute for Animal Health, has joined Israeli microbiologist Dr. Marcelo Ehrlich of the University of Tel Aviv to learn what makes bluetongue tick, unlocking the inner workings of its deadliest strain with discoveries that could help in designing a lasting universal vaccine.<\/p>\n

\u201cNo one thought bluetongue would spread this far, and with current vaccines even the most watchful countries can\u2019t protect themselves from it,\u201d said Parker. \u201cInsects carrying bluetongue don\u2019t respect national borders, and climate change has let them expand their range. Meanwhile this new strain is especially virulent: good at bursting through cells to infect new ones. If we can learn how bluetongue kills cells and why this strain is so good at it, we may be able to better control its spread.\u201d<\/p>\n

When bluetongue invades a cell it creates a protein called NS3, reproduces, and eventually bursts through the cell. All strains produce NS3, but the more virulent strains produce an altered form. When experiments in Israel suggested NS3 helps degrade cells so the virus can escape, Ehrlich contacted Parker, a former collaborator, who studies cell death.<\/p>\n

The pair has created a novel plasmid-based system to discover exactly what NS3 does using reverse genetics. While standard \u201cforward\u201d genetics start with a trait then look for the genes influencing it, recently developed \u201creverse\u201d genetics systems manipulate specific genes to look for their effects. Parker and Ehrlich are making mutant bluetongue viruses that alter NS3 to see what it does in a cell.<\/p>\n

\u201cReverse genetics has become the gold standard for doing molecular virology,\u201d said Parker. \u201cIt\u2019s particularly useful for studying specific proteins. But until recently it was very difficult to develop these systems for reoviruses, the family to which bluetongue belongs.\u201d<\/p>\n

In 2006 one of Parker\u2019s collaborators created a new reverse genetics system that uses plasmids, easily copied pieces of bacterial DNA, to insert viral mutants directly into cells, skipping steps that once impeded the study of reoviruses.<\/p>\n

\u201cThe majority of Cornell\u2019s microbiology labs do this every day: they take plasmid DNA, mutate it, and study the effect on a protein,\u201d said Parker. \u201cIt\u2019s much more convenient and makes transferring genetic material between labs easier, enabling better collaboration. In Israel, where virulent bluetongue is common, Marcelo will conduct experiments that for biosecurity reasons could never be conducted in the US, where strains are relatively benign.\u201d<\/p>\n

The researchers took an unusual route in constructing the mutant viruses they will study: hiring a company to synthesize them from scratch.<\/p>\n

\u201cThese days you can make a pathogen by putting in an order,\u201d said Parker. \u201cIt was first done for Polio virus, and more and more researchers are taking this approach. It\u2019s cheaper and faster than paying grad students to spend months cloning genes. People used to learn PCR\u2014nowadays my lab staff learn how to place an order, making sure the DNA sequence they ask for is right.\u201d<\/p>\n

\u201cViruses are often seen as mysterious and dangerous things that are hard to control. There\u2019s some truth to that, but we are making significant progress in our abilities to manipulate viruses in ways that help us understand them better in order to develop better vaccines and treatments.\u201d<\/p>\n

Their work is supported by the US-Israel Binational Agricultural Research Development (BARD) Fund, which funds collaborative research to solve agricultural problems.<\/p>\n

\"File:Map<\/p>\n

The molecular epidemiology of bluetongue virus (BTV) since 1998: routes of introduction of different serotypes and individual virus strains.\u00a0<\/em><\/p>\n

Map Source<\/a><\/p>\n

—<\/p>\n

\u2018Scopes Magazine
\nFebruary 2012<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Cornell-Israel collaboration works backwards to fight virus threatening livestock trade worldwide European livestock beware: bluetongue virus is coming your way, and it\u2019s deadlier than ever. Once limited to warmer climes, the insect-borne virus\u2019s new highly pathogenic strain has been spreading northward since 2006, reaching farther into Europe than ever before. Bluetongue\u2019s rise threatens ruminants and […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[28,34,7,8,20],"tags":[],"class_list":["post-343","post","type-post","status-publish","format-standard","hentry","category-scopes-magazine","category-epidemiology","category-farm-animals","category-food","category-research"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/carlyhodes.com\/index.php?rest_route=\/wp\/v2\/posts\/343","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/carlyhodes.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/carlyhodes.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/carlyhodes.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/carlyhodes.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=343"}],"version-history":[{"count":0,"href":"https:\/\/carlyhodes.com\/index.php?rest_route=\/wp\/v2\/posts\/343\/revisions"}],"wp:attachment":[{"href":"https:\/\/carlyhodes.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=343"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/carlyhodes.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=343"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/carlyhodes.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=343"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}