Scientists claim to have found that a rare immune cell helps the immune system "remember" an attack, a key finding which may pave the way for new and more effective treatments for immune disorders. A team at the Walter and Eliza Hall Institute says the cells, called T follicular helper cells, represent less than half of one per cent of all immune cells, but play a key role in antibody production and developing long-lasting immunity. However, the cells are also dramatically increased in chronic inflammatory disease, suggesting that they could be a therapeutic target for treating these diseases. The team, led by Dr Katja Luthje, discovered a means of identifying the rare T follicular helper cells while they are actually involved in instructing immune response, revealing for the first time the possible fates of these cells. Dr Luthje said the research team discovered T follicular helper cells were essential for developing strong and specific antibody responses to infectious agents. "Antibodies are fundamental to the body`s defence against infection. Antibody production critically relies on the interaction of two cell types: B cells that produce antibody, and helper T cells that recruit and `teach` the B cells how to respond to infectious agents. "In this study, we used a special fluorescent protein to help identify exactly which cells were involved in the process, and discovered that, amongst the rare T follicular helper cells, only a subset were actively involved in instructing B cells in antibody production," he said. The scientists say that this finding is incredibly important for the development of vaccines, which relies on immune memory to prevent subsequent infections. The findings have been published in the `Nature Immunology` journal.