(Press-News.org) New research on mice has shown that pulmonary administration of granulocyte macrophage-colony stimulating factor (GM-CSF) significantly reduces flu symptoms and prevents death after a lethal dose influenza virus. While GM-SCF therapy for humans as a flu prophylaxis or treatment may be years away, the study results were striking: All of the mice treated with GM-SCF survived after being infected with the influenza virus, whereas untreated mice all died from the same infection.
"Such unique and unambiguous results demonstrate the great potential of GM-CSF and may be the remedy for a critical public health priority: developing strategies to reduce the morbidity and mortality from influenza," said Homayoun Shams, PhD, principal investigator of the study.
The results were posted online ahead of the print edition of the American Journal of Respiratory and Critical Care Medicine.
Each year, flu infects 3 to 5 million people worldwide and is responsible for 250-500,000 deaths, according to the World Health Organization. Genetic mutations of influenza virus reduce the potency of flu vaccines, and a vaccinated person may contract flu, develop complications and even die due to poor host immune responses to vaccine or mutated virus strains.
Vaccinations work by activating the host's adaptive immunity in advance of infection. However, if the immune system is compromised, a vaccination may not provoke an adequate immune response to confer protection. Additionally, vaccine-induced immunity takes time to develop. If an individual is exposed shortly before or after being vaccinated, the vaccine will likely have little or no effect on his or her immunity.
"Improved methods to protect against influenza are sorely needed, particularly in the face of an impending pandemic. Development of such methods hinges on understanding host mechanisms that confer robust protection against influenza," said Dr. Shams. "Despite the widespread use of vaccines, influenza causes significant morbidity and mortality throughout the world, and those with poor immune systems are particularly more susceptible—such as very young, elderly or immunocompromised individuals."
GM-SCF boosts innate immunity to make it immediately effective against the virus, and its protective effect has not been shown to be strain dependant so far. Alveolar macrophages (AM), which are enhanced by GM-SCF, are an essential piece of the innate immune response and are known to contribute to host defense against flu infections in animal models.
"Unlike a vaccine, GM-SCF does not rely heavily on the body's ability to mount an immune counter-attack against a specific antigen or virus strain, but enhances the speed of local responses to virus infection and delicately balances the host immune responses," explained Dr. Shams.
Dr. Shams and colleagues wanted to test the idea that boosting AM by introducing GM-SCF would protect against flu. They used three types of mice to test their hypothesis: wild-type (WT) mice, transgenic mice that do not express any GM-SCF (GM-/-), and transgenic mice that express GM-SCF only in the lung (SPC-GM). They infected all three strains of mice with lethal doses of influenza virus. After progressive weight loss, all WT and GM-/- mice died within days. In contrast, all SPC-GM mice survived, and they gained back the weight they initially lost after a short period.
"This proves the concept that GM-SCF, only in the lung, is sufficient to provide complete protection against infection with otherwise lethal doses of influenza virus strains," said Dr. Shams. "This finding delineates a novel means of conferring marked resistance to influenza through enhancing innate immune mechanisms that depend on AM. We found that SPC-GM mice that overexpress GM-SCF only in the lungs are highly resistant to infection with laboratory and clinical influenza strains, including the recent pandemic swine H1N1 strain."
GM-SCF is already in use in humans as a therapy for neutropenia, and Dr. Shams hopes to eventually test its effectiveness in clinical trials for preventing or treating flu exposure. "If additional work determines that delivery of GM-SCF to the lungs after onset of symptoms improves the outcome of influenza infection, this strategy has great potential to represent a new intervention to reduce morbidity and mortality from influenza in humans," he said.
INFORMATION: END
Scotland's first fully protected marine reserve, and only the second in the UK, is already providing commercial and conservation benefits, according to new research.
After only two years in operation, it is already showing positive signs for both fishermen and conservationists, according to a study by the University of York and the Community of Arran Seabed Trust (COAST).
The research, published in the journal Marine Biology, shows that commercially valuable scallops and several species of algae known to promote biodiversity are much more abundant in the marine reserve, ...
Delivering the News: How to Tell the Kids You Are Getting a Divorce
Choosing to get a divorce can be a difficult decision, especially if you and your spouse have children. However, communicating the facts of your decision and simply explaining how the children's lives will change -- and how they will stay the same -- can make the transition a better experience for them.
To deliver the divorce news in an understandable and kid-friendly way, Lynn Louise Wonders, a licensed professional counselor who works with children and families going through divorce, offers the ...
PHOENIX, Ariz.-- April 22, 2011-- A gene called PVT1 may help reduce the kidneys ability to filter blood, leading to kidney disease, kidney failure and death, according to a study published today by researchers at the Translational Genomics Research Institute (TGen).
The TGen team found PVT1 expression levels increased up to 5-fold in response to hyperglycemia, or high blood sugar, a condition that often accompanies diabetes.
But by knocking down or reducing the expression of the PVT1gene, TGen researchers lowered the amount of proteins associated with the excessive ...
An article in Science Signaling by researchers at the RIKEN Research Center for Allergy and Immunology (RCAI) has clarified for the first time the mechanism governing differentiation of B cells into antibody-producing plasma cells. The finding establishes a role for the extracellular signal-regulated kinase (ERK) signaling pathway in B cell differentiation, a key step toward the development of B cell-targeted drugs for treatment of autoimmune diseases and allergies.
As the only cells in the body that produce antibodies, B cells play an essential role in the immune system's ...
Dallas Man Petitions Texas Supreme Court for Review of Gay Divorce Case
Texas is one of several states that have amended their constitutions to limit legal recognition of marriage to one man and one woman. Same-sex couples who want to formalize certain aspects of their relationship can explore Texas domestic partnership solutions, including adoption, cohabitation agreements and designation of end-of-life rights. But given that other states have formally recognized gay marriage, many Texans have traveled to places like Iowa and Massachusetts to obtain a legal marriage.
If ...
PHILADELPHIA--During embryonic development, cells migrate to their eventual location in the adult body plan and begin to differentiate into specific cell types. Thanks to new research at the University of Pennsylvania, there is new insight into how these processes regulate tissues formation in the heart.
A developmental biologist at Penn's School of Veterinary Medicine, Jean-Pierre Saint-Jeannet, along with a colleague, Young-Hoon Lee of South Korea's Chonbuk National University, has mapped the embryonic region that becomes the part of the heart that separates the outgoing ...
Mortgage Fraud and the Financial Crisis
In Oregon and across the country, the fallout from the subprime mortgage collapse and the ensuing financial meltdown has still not ended.
This fallout does not only include depressed housing values and the seemingly endless waves of foreclosures that have affected so many lives. It also includes the unfairness of bringing mortgage fraud cases against people who were rank-and-file players in the deregulated mortgage industry.
Mortgage fraud is a serious charge that often requires a vigorous federal criminal defense.
Systemic ...
Michigan Crime and Punishment for Reckless or Drunk Driving
Two fiery Michigan crashes lead to very different charges. In 2009, Robert Gorter crashed his car into a truck in a construction zone on I-196. Authorities say he was driving too fast for the conditions when he struck the truck. Both the car and the truck caught fire and the truck was pushed down an embankment. Gorter's 83-year-old wife and the 70-year-old driver of the truck were killed instantly.
In 2010, Lauraetta Carey pursued her boyfriend and his female companion at speeds of up to 100 mph before he ...
Humans are not born as blank slates for nature to write on. Neither are they behaving on genes alone.
Research by Lee A. Thompson, chair of Case Western Reserve University's Psychological Sciences Department, and colleagues found that the link between Attention-Deficit/Hyperactivity Disorder (ADHD) and academic performance involves a complex interaction of genes and environment.
Genetic influence was found to be greater on reading than for math, while shared environment (e.g., the home and/or school environment the twins shared) influenced math more so than reading. ...
The University of Connecticut and California State University researchers found that seafloor communities in a restricted fishing area in NOAA's Stellwagen Bank National Marine Sanctuary showed indications of recovery from chronic fishing gear impacts but is not fully stable. The finding is significant because bottom trawlers, dredges and certain gillnets, for example, can alter the ocean floor and benthic ecosystems that provide food and shelter for fish and other marine species.
The Western Gulf of Maine habitat closure area overlaps 22 percent of the sanctuary and ...
