The image at left shows tissue from the intestine of a normal mouse. At right, in a mouse infected with Toxoplasma gondii, the intestines are inflamed and have lost much of their normal structure. Image: Kirk Jensen

Toxoplasma gondii, a parasite that infects about one-third of the world’s population, comes in several strains. some can have severe consequences such as encephalitis, while others produce no noticeable symptoms.

Jeroen Saeij, an MIT biologist who has been studying Toxoplasma for several years, is trying to figure out the root of that discrepancy. in his latest work, he found that two of the three most common strains of Toxoplasma produce a protein that actually suppresses inflammation in the infected host — a discovery that could help researchers develop new ways to shut off inflammation in patients infected with the more threatening strains of Toxoplasma, or even in people with other inflammatory diseases such as Crohn’s disease.

“There’s a lot of these inflammatory diseases, and if there’s a general pathway that’s really good at quelling inflammation, there might be [drug] applications,” says Saeij, an assistant professor of biology.

Saeij and his colleagues described the new discovery in the June 15 issue of Cell Host & Microbe. Lead author of the paper is postdoc Kirk Jensen.

Inflammation

Toxoplasma spores, which can infect nearly any warm-blooded animal, are often found in dirt; humans can be infected by eating undercooked meat or unwashed vegetables. the parasite can cause encephalitis in individuals with suppressed immune systems and is also harmful to fetuses whose mothers become infected during pregnancy. some strains, primarily those found in South America, can lead to blindness.

There are about a dozen major types of strains of Toxoplasma; in North America and Europe, the most common is the type II strain, which is also the one most often isolated from patients with complications from Toxoplasma. in a previous paper, Saeij and colleagues showed that type II produces a form of the protein GRA15 that causes inflammation, an immune reaction that is meant to destroy invaders but can also damage the host’s own tissues if unchecked.

In the new paper, Saeij showed that type II also has a variant form of another protein called ROP16. the researchers found that in types I and III, which are less often found in patients with Toxoplasma symptoms, ROP16 suppresses inflammation in the host. However, the form of ROP16 found in type II has no such effect.

When the researchers inserted type I ROP16 into the type II strain, inflammation was suppressed.

Why opposite results from strains of the same parasite? the researchers believe different forms of the parasite evolved to take advantage of different immune reactions from potential hosts. Toxoplasma wants to provoke some inflammation in the host, because inflammation helps the host survive acute infection. As a consequence, the parasite can form tissue cysts that spread to other victims through carnivorism. However, too much inflammation might kill the host and stop the parasite’s life cycle. By employing different strategies, the parasite can be successful in hosts with varying inflammatory responses.

Jon Boyle, an assistant professor of biological sciences at the University of Pittsburgh who was not involved with this research, agrees with this assessment: “What the paper shows really well is that you have these different strains and even though they are quite similar, each type is adapted to different host environments.”

A model for Crohn’s disease

In the new paper, the researchers studied Toxoplasma infection in mice. the resulting inflammation of the mouse intestine strongly resembles the intestinal inflammation seen in Crohn’s disease, which affects about half a million people in the United States.

It is unknown if any of these cases are actually caused by Toxoplasma, but Saeij says some studies have shown a higher incidence of Toxoplasma in Crohn’s patients compared with the general population.

Saeij and Jensen are now trying to figure out how the ROP16 protein exerts its anti-inflammatory effects, which could help identify new approaches to developing anti-inflammatory drugs. However, that will likely require many more years of research, Saeij says.

“in reality, going from a discovery to a drug can take decades,” he says. “you hope that you contribute to something like that, but that’s always a long road.”

Provided by Massachusetts Institute of Technology (news : web)

On 10th March 2011 researchers says that a new protein molecule derived from growth factor progranulin provide treatment for the inflammatory diseases like rheumatoid arthritis. the development of this protein in the body produces cytokines that control the level of cartilage. Appropriate level of cartilage prevents arthritis in the body. these protein molecules are secreted by the nervous system and other immune system of the body.Arthritis is taken from a Greek word which means “joint” and its Latin meaning is “inflammation”. it affects the muscles and the skeleton system of the human body specially the joints. it becomes the main cause of disability in the people of over 55 years of age.

Arthritis is not a single disease. it covers other medical conditions.

There are more than hundred types of arthritis. some are given below:

1. OsteoarthritisIt is a type of arthritis in which cartilage loses its elasticity. if the cartilage is stiff it damages easily. Cartilage functions as a shock absorber. when the cartilage is damaged the tendons and the ligaments are damaged too as a result it causes pain in the muscles and bones.

2. Rheumatoid arthritisIn this arthritis the muscle membrane is damaged and it causes swelling and pain. if this type of arthritis is not treated well it can cause deformity of bones. Rheumatoid arthritis is more common in women than in men and it strikes the patient between the age of 40 to 60. Children and older people can also be affected by this disease.

3. Infectious arthritisThe infection in the synovial fluid or in the tissue of bone can be caused by a bacteria but it can also be caused by the viruses and other fungi. these bacteria, fungi are spread in the body through a blood and it infects the nearby tissues and the bones too. the people who had arthritis ever before in their life and those who have such virus in their body, they have the more chances of developing arthritis.

4. Juvenile rheumatoid arthritisThis is a type of arthritis that affects an individual of age 16 or less. the juvenile rheumatoid arthritis is of three types:

• Pauciarticular JRA

It is the most common type. In this a child feels pain in up to 4 joints.

• Polyarticular JRA

The affects of this arthritis are more severe and it gets worst with the passage of time.

• Systematic JRA

It is the least common type of arthritis. it can spread to the distant organs of the body but it can be the most dangerous type of JRA.

A joint where one bone is joined to another bone that joint is hold with the ligaments. these ligaments are elastic bands they keep bones at their place and the muscles contact and relax to make the joint move freely.

The cartilage allows the two bones not to rub with each other while moving. the covering of the cartilage helps the joint to move smoothly and painlessly.There is a capsule that surrounds the joint. There is fluid in the joint known as synovial joint. this fluid is beneficial for beneficial for bones.

If an individual has the arthritis things go wrong with bones. the damage that is caused to the bones depends on the type of the arthritis. as a result of the arthritis the cartilage finishes due to infection and many other factors.

The symptoms of arthritis takes time to develop but it get worse with the passage of time. these symptoms affect the joints of hip, knee, hands and spine, fingers, arms, legs, wrists, ankle, jaw, shoulder. Following are the symptoms of arthritis:

Arthritis can be diagnosed blood tests, physical tests. x- Rays and CT scan.

Treatment of arthritis consists of physical therapy, medications.

Physical therapyPhysical therapy is helpful to maintain the flexibility of the bones. There are many types of physical therapies. the type of physical therapy given to a patient depends on the type of arthritis an individual has. different exercises are given to the patient that stabilize weaken joints. Exercise is an important part of arthritis therapy.

Medication for arthritisNSAIDs, COX-2 inhibitors, Salicylates, Glucocorticoids, Anti Malarials, Minocycline, and cyclosporine are the medicines that are used to cure the arthritis.

Diet impact on arthritisDiet has an important impact on the arthritis. it provides you with nutrition and it also maintains the weight of the body because people start losing weight during arthritis.

Doctors advised patients to avoid eating fats, cream, red meat and cheese. Patients should eat plenty of vegetables, fruits etc.

The prevention of arthritis can seem very difficult but there are many ways that can prevent arthritis from occurring. the use of arthritis supplements (Glucosamine and Cetyl myristoleate) also helps to prevent the arthritis. these supplements can be found in the form of liquid, powder or pills.the disease of arthritis can make one’s life very difficult but therapies can make life better. People with arthritis can go for medical health and treatment and there is no definite cure of arthritis but there are ways which can reduce the effects of arthritis. it affects the people in different ways patients may feel uncomfortable that they lose their grip. Being diagnosed with arthritis does not mean that you cannot live healthy life anymore. with some changes in life style the bad effects of arthritis can be removed.