WASHINGTON (AP) - Think your job's tedious? Try beheading 100 mosquitoes anhour.
Gently, no smushing allowed. Malaria parasites lurk in thesemosquitoes' salivary glands, and a small company on the outskirtsof the nation's capital needs them unharmed for a dramatic test— attempting the first live vaccine to fight malaria.
Mutant mosquitoes, too, might help one day. Their eyes glowgreen under a special microscope, a sign that the University ofMaryland's genetic engineering has taken hold: These bugs shouldbecome super malaria incubators, a bid to eventually get more ofthe vaccine's key ingredient per mosquito.
If the two experiments sound far-fetched, consider: A globalpush is on to eradicate this ancient scourge, and increasinglyscientists are exploring how to use the mosquito itself to help— not just with the vaccine research but also, conversely, bybreeding insects that are less able to spread malaria.
"It's really gene therapy for insects," says Dr. DavidO'Brochta, who heads the Maryland university's novel laboratoryand, with government funding, is creating both bug types.
It's a change in philosophy, and O'Brochta cautions that it'sfar from clear that any of the mosquito research will pan out.
A vaccine made of living malaria parasites "was consideredlaughable five to seven years ago," says Dr. Stephen Hoffman, CEOof Rockville, Md.-based Sanaria Inc.
In the Navy in the 1990s, Hoffman irradiated malaria-carryingmosquitoes to weaken the parasites inside them, and he and 13colleagues subjected themselves to more than 1,000 bites. Usuallymalaria parasites race to the liver and multiply before invadingthe bloodstream to sicken. These weakened parasites instead satharmlessly in the liver, unable to multiply but triggering theimmune system to fend off later infections. All but one of thepeople in Hoffman's test, himself included, were immune when bittenby regular malaria-infected mosquitoes over the next 10 months.
The question was how to turn that protection into a long-lastingshot. Critics said "it couldn't possibly be made," Hoffman recalls."We were dismissed by 99 percent of the people in the malariafield."
Yet two weeks ago, with the Food and Drug Administration's OK,the first of about 100 U.S. volunteers started receiving test dosesof Sanaria's vaccine, in a first-stage safety study.
Nearly a quarter-billion people get malaria each year, and itkills almost 1 million, the vast majority of them young children inAfrica. Species of Anopheles mosquitoes spread the parasite. Bednetting and insecticides are the chief protection. Advanced testingof a different experimental vaccine from GlaxoSmithKline is underway in Africa, an exciting first but one expected to provide onlypartial protection.
Hence the push by about a dozen labs worldwide to breedmalaria-resistant mosquitoes in various ways, including alteringtheir genes.
In O'Brochta's lab, Robert Harrell peers through a microscopeand jabs a mosquito egg — so small it takes a clump of themto resemble specks of dirt — with a hair-thin glass needle.He's aiming new DNA near a spot that should develop intoreproductive organs, so the resulting mutant mosquito can pass itsnew trait to next generations.
Inheritance is a hurdle: Of the mutants that survive toadulthood, only about 2 percent of their progeny remain geneticallymodified.
In a humid insectary that resembles a walk-in safe, O'Brochtapulls out a bucket swarming with Anopheles gambiae, the speciesthat drives malaria in Africa. Deprived of human blood in the lab,these mosquitoes will suck on a sedated mouse for food. (The labmouse, which loses a little blood, then gets a two-week vacation— and no, mosquitoes don't make mice itch.)
But in the wild, this particular species hunts people like abloodhound, so a malaria-resistance gene would have to spread a lotfaster through mosquito populations to work. How to speed thatspread is O'Brochta's main focus.
The flip side of his research brings us back to Sanaria.
It takes 3,000 mosquitoes — relatives of A. gambiae,dissected by hand — to make a batch of the experimentalvaccine, says Sanaria entomologist Adam Richman. In anFDA-sanctioned "clean room," workers dunk frozen mosquitoes inalcohol, killing them but not the stunned parasites inside. Then,peering through a microscope, the workers carefully pull eachmosquito's head from its body. Out pops an almost translucent glob,the glands, ready for purification.
The company's eventual goal: a mosquito that can harbor 200,000sporozoites, the immature parasites, twice the typical amount. Inhis nearby university lab, that's what O'Brochta is trying tocreate by switching off a gene that protects the bug when it eatsmalaria-infected human blood.
"No one has ever made transgenic mosquitoes with this geneknocked out," he says. "We want to cripple its immune system sowhen it takes an infected meal, it gets infected at very highlevels.
Copyright 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
It's going to be the coldest night of the year. One thing to keep in mind - when the weather gets this cold, it can be dangerous to you.
A Terre Haute man found not guilty of manslaughter and guilty of battery.The jury handed down the verdict Wednesday afternoon.
An investigation is underway into an early morning crash.
Toys are getting ready for distributing for the annual Toys for Tots toy drive.
The same Illinois state’s attorney who’s charging the biological mother of murder victim Willow Long is cautioning those in the court of public opinion not to be too quick to put blood on the young mother’s hands.