ASU study explores components of the immune system

Unless you're twins, you're unlikely to be mistaken for someone else. Similarly, since childhood, we have had a strong sense of self as separate from all other human beings.

The immune system, on the other hand, has a far harder time separating itself from non-self. If this sophisticated monitoring system fails to detect a foreign invader, such as a germ or virus, severe and uncontrollable sickness might occur.

However, under some situations, the immune system can become hyper-vigilant, mistaking our own tissues for alien objects and attacking them, resulting in autoimmune illness. Some tumors have been linked to autoimmune responses.

Joshua LaBer of Arizona State University and his colleagues tracked immune system components called autoantibodies in a recent investigation. Autoantibodies have been linked to a variety of devastating autoimmune disorders, but investigations have discovered that they may also be detected in healthy people.

This feature may make the clinical use of autoantibodies as autoimmune disease sentinels more difficult, emphasizing the significance of further research.

Better understanding of the incidence and significance of autoantibodies in human health and illness might lead to the development of more effective diagnostics and therapies for a variety of disorders.

Dr. Laber is the Executive Director of ASU's Biodesign Institute and the Biodesign Institute's Director of Research. The Center for Personalized Diagnostics is directed by Virginia G. Piper.

Biological civil war

Autoimmune illnesses are a common occurrence, affecting over 23 million people in the United States. Over 80 autoimmune illnesses have been found by researchers, including familiar diseases like type 1 diabetes, lupus, multiple sclerosis, and rheumatoid arthritis, as well as more obscure disorders that can be difficult to detect. Women account for over 80% of autoimmune disorders, for reasons that experts are still attempting to figure out.

The fundamental processes that cause autoimmune responses are still a mystery to science. Infection is frequently the cause of such disorders. Autoimmunity is influenced by the two basic components of the so-called adaptive immune system. T cells and B cells are white blood cells, often known as lymphocytes. Lymphocytes are necessary for life and are critical for sustaining health. The presence of foreign substances known as antigens is detected by these sentinels, who are continually monitoring the bloodstream.

Pathogens such as bacteria, viruses, and fungi are protected by T cells. They're also capable of attacking and destroying cancer cells. Antibodies are proteins secreted by B cells that either disrupt the connection or target infected cells for destruction by other cells. Antibodies neutralize the detrimental effects of foreign substances such as viruses and poisons by binding to them. If an antibody attaches to a virus, for example, it can prevent the invader from infecting a healthy cell. B cells can also recruit other specialized immune cells to assist them in migrating to contaminated cell locations and destroying them.

Molecular mimicry is the mistargeting of self-antigens due to their resemblance to disease antigens, and it has been linked to a variety of autoimmune diseases, including rheumatoid arthritis and multiple sclerosis.

Scavenger hunt for antibodies

A new study looks at frequent autoantibodies seen in healthy people. Despite the fact that these prevalent autoantibodies do not cause illness, they are found in at least 40% of people who are tested. At least some of these frequent autoantibodies have most certainly been misidentified as antibodies.

A meta-analysis of nine datasets was done by the researchers. A protein microarray is the instrument of choice for discovering common autoantibodies. Thousands of individual proteins are bonded to a glass slide in this experiment. Antibodies (in this example, autoantibodies) attach to certain protein antigens when a sample of blood is spread in a microarray.

Two rounds of screening were performed on the microarray. 182 blood samples from healthy people were analyzed against 7,653 human proteins in the first round. 90 blood samples were analyzed against 1,666 human proteins in the second round. A total of 77 common autoantibodies were discovered during the research.

Blood samples were taken from healthy people of both sexes ranging in age from birth to 84 years old. The number of autoantibodies grew from birth until puberty and then stabilized, according to the findings. Furthermore, the quantity of autoantibodies was identical independent of gender, which is remarkable given the substantial gap in the frequency of autoimmune illness between males and females.

Why do normal autoantibodies fail to induce autoimmune illness is another unsolved mystery. Although such antibodies appear to have slipped through the cracks in the immunological tolerance screening process, their presence in the body remains harmless. Autoantibodies are assumed to be required for autoimmune disease to arise and form complexes with autoantigens, which can be prevented in the case of normal autoantibodies.

Future study on the nature of autoantibodies is expected to uncover many more mysteries. Only around half of all human proteins were evaluated in this study. Additional normal autoantibodies are almost certainly still to be discovered.