B cells can act alone in autoimmune disease

Aug 07, 2008

B cells, the source of damaging autoantibodies, have long been thought to depend upon T cells for their activation and were not considered important in the initiation of autoimmune diseases like lupus or rheumatoid arthritis.

In the Aug. 7 online issue of the journal of Immunity, Yale University researchers turn this paradigm on its head by showing that in systemic autoimmune diseases B cells can be activated the absence of T cells.

The study suggests new ways to intervene in the immune system's chronic attacks on the body's own tissue.

The findings were surprising because many scientists believed that B cells remain quiet in autoimmune diseases unless they are stimulated first by T cells, said Mark Shlomchik, MD, professor of laboratory medicine and immunobiology at the Yale School of Medicine and senior author of the study.

"It became a chicken or egg problem. If cooperation between T and B cells is needed to create an autoimmune disease, who falls off the fence first, and why?'' Shlomchik said.

Recently this same Yale group along with collaborators at Boston University discovered an unexpected role in autoimmunity of Toll-like receptors, previously thought to be stimulated by molecules expressed on microbial pathogens. Shlomchik and his colleagues showed that they can also recognize and react to "self" molecules, in particular mammalian DNA and RNA. When this occurs, these receptors help activate B cells that make the classical autoantibodies of lupus.

The new Yale study now shows that these signals substitute for T cells in starting the autoimmune process in B cells. The researchers propose that once B cells are activated via Toll-like receptors, they can subsequently recruit T cells and that this can lead to a "vicious cycle" of chronic autoimmune disease in which the two types of cell activate each other.

The findings might explain why treatments that target T cells in autoimmune diseases have fared relatively poorly, while newer treatments aimed at B cells have shown great promise, he said.

The current study is a direct outgrowth of groundbreaking work conducted at Yale over the last 15 years that showed that elements of the innate, or non-specific immune system such as Toll-like receptors, needed to be triggered before more sophisticated adaptive immune system of humans and other animals could hone in on specific pathogens.

Source: Yale University

Explore further: Suspected Ebola patient tests negative in Sweden (Update)

add to favorites email to friend print save as pdf

Related Stories

Immune cell plays unexpected role in autoimmune disease

Dec 16, 2010

A new study provides fascinating insight into the underlying pathology associated with the autoimmune disease, systemic lupus erythematosus (SLE). The research, published by Cell Press in the December issue ...

Mining the 'wisdom of crowds' to attack disease

Sep 28, 2010

Crowdsourcing, the act of contracting out problems to large groups rather than tapping individual experts, has solved puzzles in fields such as marketing, engineering and computer software. But can the wisdom of crowds help ...

Study points to increased risk for lupus in men

Sep 02, 2010

Lupus Research Institute-funded researcher Betty Tsao, PhD, at the University of California Los Angeles has discovered that humans -- males in particular -- with a variant form of the immune receptor gene "Toll Like Receptor ...

Novel Protein Essential for Successful Pregnancy

May 27, 2010

(PhysOrg.com) -- Researchers at Yale School of Medicine and their colleagues at the Society for the Investigation of Early Pregnancy have helped clarify the function of a unique protein called Preimplantation ...

Medical students may soon be tested on evolution

Jan 26, 2010

What does evolution - a field that often deals with changes over many generations - have to do with preventing and treating disease in our lifetime? A lot, some scientists say. If recent recommendations are ...

Recommended for you

19 new dengue cases in Japan, linked to Tokyo park

3 hours ago

Japan is urging local authorities to be on the lookout for further outbreaks of dengue fever, after confirming another 19 cases that were contracted at a popular local park in downtown Tokyo.

User comments : 0