Health and Medical News and Resources

General interest items edited by Janice Flahiff

How bacteria behind serious childhood disease evolve to evade vaccines (& related article about bad immunity genes)

Vaccines

Vaccines (Photo credit: www78)

How bacteria behind serious childhood disease evolve to evade vaccines

From the 29 January 2012 Science Daily article

 Genetics has provided surprising insights into why vaccines used in both the UK and US to combat serious childhood infections can eventually fail. The study, recently published in Nature Genetics, which investigates how bacteria change their disguise to evade the vaccines, has implications for how future vaccines can be made more effective…

n spite of the success of the vaccine programmes, some pneumococcal strains managed to continue to cause disease by camouflaging themselves from the vaccine. In research funded by the Wellcome Trust, scientists at the University of Oxford and at the Centers for Disease Control and Prevention in Atlanta studied what happened after the introduction of this vaccine in the US. They used the latest genomic techniques combined with epidemiology to understand how different serotypes of the pneumococcus bacteria evolve to replace those targeted by the initial vaccine.

The researchers found bacteria that had evaded the vaccine by swapping the region of the genome responsible for making the polysaccharide coating with the same region from a different serotype, not targeted by the vaccine. This effectively disguised the bacteria, making it invisible to the vaccine….

Why bad immunity genes survive -Utah study implicates arms race between genes and germs

 IMAGE: This electron microscope image shows yellow particles of a mouse leukemia virus named Friend virus emerging or “budding ” out of an infected white blood cell known as a T-cell. By…

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SALT LAKE CITY, Feb. 6, 2012 – University of Utah biologists found new evidence why mice, people and other vertebrate animals carry thousands of varieties of genes to make immune-system proteins named MHCs – even though some of those genes make us susceptible to infections and to autoimmune diseases.

“Major histocompatibility complex” (MHC) proteins are found on the surface of most cells in vertebrate animals. They distinguish self from foreign, and trigger an immune response against foreign invaders. MHCs recognize invading germs, reject or accept transplanted organs and play a role in helping us smell compatible mates.

“This study explains why there are so many versions of the MHC genes, and why the ones that cause susceptibility to diseases are being maintained and not eliminated,” says biology Professor Wayne Potts. “They are involved in a never-ending arms race that causes them, at any point in time, to be good against some infections but bad against other infections and autoimmune diseases.”

By allowing a disease virus to evolve rapidly in mice, the study produced new experimental evidence for the arms race between genes and germs – known technically as “antagonistic coevolution.” The findings will be published online the week of Feb. 6, 2012, in the journal Proceedings of the National Academy of Sciences.

Potts, the senior author, ran the study with first author and former doctoral student Jason Kubinak, now a postdoctoral fellow in pathology. Other co-authors were biology doctoral student James Ruff, biology undergraduate C. Whitney Hyzer and Patricia Slev, a clinical assistant professor of pathology. The research was funded by the National Science Foundation and the National Institute of Allergy and Infectious Diseases.

February 9, 2012 Posted by | Medical and Health Research News, Public Health | , , , , , , | Leave a comment

New Findings Challenge View of Key Part of Immune Defense

Cells of the innate immune system include mast...

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New Findings Challenge View of Key Part of Immune Defense

From a March 3 2011 Science Daily news item

 

ScienceDaily (Mar. 3, 2011) — The natural killer cells of our immune defense are activated for an extended period after the acute infection, which challenges the prevailing view that the elevation and activation of cells quickly pass. This is shown in a study regarding vole fever that was recently published by researchers at Umeå University, Sweden in Journal of Experimental Medicine.**

***For suggestions on how to get this article for free or at low cost, click here

 

March 4, 2011 Posted by | Medical and Health Research News | , , , , , | Leave a comment

Farm Environment, Cats Help Kids Avoid Skin Disease & Related Article (Growing Up on Farm Strengthens Immune System)

Farm Environment, Cats Help Kids Avoid Skin Disease

HealthDay news image

European researchers report rural living less likely to lead to atopic dermatitis for infants

Childhood exposure to germs in the environment strengthens their immune system, according to current scientific evidence. (See  Immune System (http://www.niaid.nih.gov/topics/immuneSystem/Pages/immunity.aspx) by the National Institute of Allergy and Infectious Diseases [NIAID])

Now it seems that the environment not only confers immunity through not only interacting with a child’s immune system after birth, but before birth.

Excerpts from a recent Health Day news article by Robert Preidt

WEDNESDAY, Dec. 8 (HealthDay News) — The children of mothers who were around farm animals and cats during pregnancy are less likely to develop atopic dermatitis in their first two years of life, new European research shows.

Atopic dermatitis (also called atopic eczema) is a chronic and painful inflammation of the skin that frequently occurs in childhood. The condition affects up to 20 percent of children in industrialized countries and is one of the most common childhood skin diseases….

….Along with the first finding, the researchers also identified two genes associated with a child’s reduced risk of developing atopic dermatitis in the first two years of life.

The findings support the theory that a gene-environment interaction with a child’s developing immune system influences the development of atopic dermatitis, said the researchers.

The study appears in the Journal of Allergy & Clinical Immunology.***
[The abstract of the article may be found here]

Previous research has found that allergies are less likely in children who grow up on farms and whose mothers lived on farms during their pregnancy.

SOURCE: Journal of Allergy & Clinical Immunology, news release, Dec. 2, 2010

Click here for suggestions on how to get the full text of the article

 

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Growing Up On A Farm Directly Affects Regulation Of The Immune System

From the 9 February 2012 Medical News Today article

Immunological diseases, such as eczemaand asthma, are on the increase in westernised society and represent a major challenge for 21st century medicine. A new study has shown, for the first time, that growing up on a farm directly affects the regulation of the immune system and causes a reduction in the immunological responses to food proteins. …

…Dr Marie Lewis, Research Associate in Infection and Immunity at the School of Veterinary Sciences, who led the research, said: “Many large-scale epidemiological studies have suggested that growing up on a farm is linked to a reduced likelihood of developing allergic disease. However, until now, it has not been possible to demonstrate direct cause and effect: does the farm environment actively protect against allergies, or are allergy-prone families unlikely to live on farms?” ,,,

 


December 12, 2010 Posted by | Consumer Health | , , , , , , , , , | 2 Comments

NIH Scientists Discover Secrets of Helper T Cells Involved in Autoimmunity

From an October 20, 2010 US National Institutes of Health press release

Scientists at the National Institutes of Health have redefined the roles of several cytokines involved in the generation of immune cells implicated in severe autoimmune diseases. The study in mice showed that development of Th17 immune cells can occur without the presence of transforming growth factor (TGF)-beta, a mediator thought to be required for Th17 cell development. The study demonstrates that the interaction of three inflammatory cytokines (proteins that influence the behavior of cells) – interleukin-6 (IL-6), IL-1-beta and IL-23 – is responsible for the creation of Th17 cells that are more active in promoting autoimmunity than Th17 cells generated with IL-6, IL-1-beta and TGF-beta. These findings reemphasize the separate roles of IL-23 and TGF-beta in immunity and autoimmunity, and open up possibilities for the development of new therapies. The study appears in the current issue of the journal Nature….

Reference

Ghoreschi K, Laurence A, Yang XP, Tato CM, McGeachy MJ, Konkel J, Ramos HL, Wei L, Davidson T, Bouladoux N, Grainger J, Chen Q, Kanno Y, Watford WT, Sun HW, Eberl G, Shevach E, Belkaid Y, Cua DJ, Chen W, O’Shea JJ. Enhanced Pathogenicity of Th17 cells Generated in the Absence of Transforming Growth Factor-ß Signaling. Nature. 2010 October 21;467(7318): 967-971.

 

 

October 27, 2010 Posted by | Health News Items | , | Leave a comment

Scientists Make Immune Cells in Mice That Fight Off HIV

HealthDay news image

Scientists Make Immune Cells in Mice That Fight Off HIV, but it will be years until this gene therapy is tested in humans.

“According to the scientists, the genetically engineered stem cells went on to create mature immune system cells, such as T-cells, in the humanized mice. After a couple of weeks, these new immune cells appeared to provide protection against HIV. The cells grew greatly in number, offering fewer targets for the virus to attack.”

The  study was released online July 2 in Nature Biotechnology.
An abstract of the article may be found here.
Access to the online full text requires a subscription.
Your local academic, hospital, or medical library may subscribe to it. Call and ask for a medical librarian.
Alternatively, many public libraries can obtain full text of individual subscription based articles through interlibrary loan.
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July 8, 2010 Posted by | Health News Items | , | Leave a comment

   

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