Immune cells promote blood vessel formation in mouse end...( A discovery in mice of immune cells ...)

A discovery in mice of immune cells that promote the formation of new blood vessels could lead to new treatments for endometriosis, a painful condition associated with infertility that affects up to 15 percent of women of reproductive age.

The formation of new blood vessels, or angiogenesis, is known to encourage the growth of tumors and endometriosis lesions. A team led by Ofer Fainaru, MD, PhD, a research associate in the Vascular Biology Program at Children's Hospital Boston and Harvard Medical School, found that dendritic cellshighly specialized immune cellshelp trigger angiogenesis in a mouse model of endometriosis. Their findings were published online last month in the FASEB journal. Judah Folkman, MD, director of Childrens Vacular Biology Program, who helped found the field of angiogenesis, was the papers senior author.

Endometriosis occurs when endometrium, a tissue normally found in the inner lining of the uterus, grows elsewhere in the bodymost commonly in the abdominal cavity. The misplaced endometrial tissue begins as small lesions, or masses, but once blood vessels are recruited, the lesions grow larger and respond to female hormones, resulting in inflammation, cyclic pelvic pain, and infertility.

In the mouse model, the researchers observed that dendritic cells infiltrate endometriosis lesions, and near the sites where they invade, new blood vessels form. Injecting mice with excess dendritic cells caused their lesions to gain more blood vessels and to grow larger.

The researchers also found that dendritic cells have a strikingly similar effect on intra-abdominal tumors.

When the researchers grew dendritic cells together with endothelial cellsthe cells that line blood vessel wallsthe endothelial cells migrated towards the dendritic cells. The team hypothesizes that dendritic cells, after embedding in a new lesion or tumor, act like foremen on a building team: they call in, direct and
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