New York, Feb 14 (IANS): Enriching T cells -- a type of white blood cell -- to attack certain cancerous diseases may prove beneficial to an increasing number of children during immunotherapy, says a study.

Younger T cells, classified as either naive T cells (newly minted cells) or stem central memory T cells (self-renewing, highly proliferative cells) were the most effective in immunotherapy, the study showed.

"Our main finding is that younger T cells are critically important in T cell immunotherapy," said David M. Barrett, paediatric oncologist at The Children's Hospital of Philadelphia (CHOP), University of Pennsylvania, US.

Collecting the T cells in the newly-diagnosed patients, even before chemotherapy, or between chemotherapy cycles, instead of after a patient relapses, may be preferable, the researchers explained.

The T cells were found to be more vulnerable to chemotherapy than older cells, showed the findings, published in the journal Science Translational Medicine.

Moreover, adding the signalling proteins interleukin-7 and interleukin-15 to T cell cultures expanded stem central memory cells in samples, the researchers revealed.

The T cell therapy is a form of immunotherapy -- manipulating the body's own immune system.

Specifically, the scientists modify T cells, the workhorses of the body's immune system, to attack B cells (B lymphocytes), other immune cells that become cancerous in specific cancers such as ALL.

The researchers first extracted a patient's own T cells and re-programmed them to hunt down and eliminate B cells after those modified T cells are returned to the patient.

The researchers followed 50 child and adolescent patients in a clinical trial of B-cell cancers at CHOP, of whom 38 had ALL and 12 had non-Hodgkin's lymphoma (NHL).