Role of Cytokines in the Acute Phase Response

摘要

We have characterized the physiological and behavioral responses to influenzainfection in mice. Studies have been run showing that ip injection of antiserum to IL-1Beta increased survival rate in influenza-infected mice, and at the same time magnified the decrease of body temperature. We hypothesize that the antiserum inactivated biological activity of the large part of IL-1Beta, an endogenous pyrogen, thereby disturbing the ratio between pyrogenic and cryogenic input on thermoregulatory centers during influenza infection. This resulted in greater expression of the cryogenic input and exaggeration of the fall of body temperature. These data support our previous observation on mice infected with the virus that lowering of body temperature (i.e. anapyrexia) during influenza pneumonitis can confer a protective effect upon an organism. We have also found that INFa and TNFa are antipyretic if given together with LPS into mice. Additionally, we observed an enhancement of the fever in mice injected with LPS and at the same time treated with TNF soluble receptor. These results confirmed our previous observation on mice treated with anti-TNFa serum and LPS, indicating that TNFa acts as the endogenous cryogen. We speculate that TNFa and INFa may account for anapyrexia in influenza-infected mice. Influenza, Cytokines, Sickness behavior, Acute phase response fever, Anorexia.