How FIP affects the feline immune response

December 3, 2013

Vermeulen BL, Devriendt B, Olyslaegers DA, et al. Suppression of NK cells and regulatory T lymphocytes in cats naturally infected with feline infectious peritonitis virus. Vet Microbiol. 2013; 164: 46-59.
 
Parts of the immune response are especially important to protect against feline coronavirus and prevent development of feline infectious peritonitis (FIP). In particular, lymphocytes play a key role in protection. These investigators examined the levels of different lymphocyte groups in cats with and without naturally occurring FIP. They found that a particular type of lymphocyte, termed the regulatory T lymphocyte, is depleted in cats with FIP. This is believed to contribute to the immune-mediated disease associated with FIP, as well as the inability of the infected cat to clear the virus.

In addition, another type of lymphocyte, the natural killer cell, was also found to be depleted in cats with FIP. These cells are an important defense against virus infections. The natural killer lymphocytes that remained were found to be less effective in eradicating virus-infected cells than they should be. 

These findings indicate that cats with FIP suffer dramatic suppression of their ability to combat the virus as well as decreased ability to prevent immune-mediated disease. This may open the door for new therapies designed to enhance the numbers and functions of these cells. [MK]

See also: Berg AL, Ekman K, Belak S and Berg M. Cellular composition and interferon-gamma expression of the local inflammatory response in feline infectious peritonitis (FIP). Vet Microbiol. 2005; 111: 15-23.