Cyclic Adenosine Monophosphate Crucial to Eosinophil Survival

Immunology

Date: 10/18/2000

(NewsRx.com) -- Cyclic adenosine monophosphate (cAMP), used to by the body as a signal to regulate some metabolic enzymes, plays an important role in promoting the survival of eosinophils, according to researchers writing in the journal

Cellular Immunology

. "The survival and apoptosis of eosinophils is of pivotal importance for controlling allergic diseases such as asthma and rhinitis," explained H.S. Chang and colleagues at Soonchunhyang University Hospital in South Korea. Chang and colleagues studied the effects of dibutyryl cAMP (dbcAMP) on the survival rates of eosinophils, white blood cells heavily involved in the immune response to allergic irritants, in the absence of other pro-immune cytokines such as interleukin-5 (IL-5) ("Role of cAMP-dependent pathway in eosinophil apoptosis and survival,"

Cell Immunol

, 2000;203(1):29-38). Treatment with dbcAMP was able to dose-dependently elevate eosinophil survival rates, they found, with increased eosinophil lifespans due at least in part to a decline in rates of apoptosis, or programmed cell suicide. While several different kinds of protein kinase A inhibitors, which block the effects of the enzyme regulated by eosinophils, were able to prevent elevated eosinophil viability from IL-5, only mitogen-activating protein kinase inhibitors (MAPKs) blocked dbcAMP's protective effects, according to the report. "We propose that a cAMP-dependent pathway may constitute an important component for regulating eosinophil survival/apoptosis," Chang and colleagues concluded, "and that cAMP may inhibit eosinophil apoptosis through the activation of PKA and of subsequent MAPK in part." The corresponding author for this report is H.S. Chang, Soonchunhyang University Hospital, Dept. Internal Medicine, Division of Allergy & Respiratory Medicine, Seoul, South Korea. Key points reported in this study include: * Cyclic adenosine monophosphate (cAMP), used to by the body as a signal to regulate some metabolic enzymes, plays an important role in promoting the survival of eosinophils * Eosinophils are white blood cells which are heavily involved in the immune response to allergic irritants * Dibutyryl cAMP was able to elevate eosinophil survival rates in a dose-dependent manner, an effect reversible by some protein kinase A inhibitors This article was prepared by Immunotherapy Weekly editors from staff and other reports.