The body’s main deposit of abdominal fat hangs like an apron over the organs of the abdomen. This adipose tissue plays important immune roles, but can also serve as a source of chronic inflammation in obese individuals, possibly contributing to metabolic syndrome. The omentum is also a common site of ovarian cancer metastasis.
The omentum’s double-edged immune functions
Fat-associated lymphoid clusters, or milky spots, filter abdominal fluid. Collections of immune cells look for signs of pathogenic invaders and internal damage and mount appropriate responses. In obese individuals, however, these cells can become over active, leading to chronic inflammation and autoimmune reactivity.
Fighting pathogensBacteria in the peritoneal cavity are filtered by the milky spots of the omentum. These lymph-like structures expand as B cells (pink) become activated, proliferate, and produce antibodies against the bacteria.
Immunity gone awry in obesityIn obesity, the adipocytes become engorged with fat, causing stress and even death. T cells (purple) become activated by self-antigens and produce inflammatory cytokines. These cytokines activate macrophages and damage tissue, thereby exacerbating inflammation.
Read the full story.