TY - JOUR
T1 - Mediation of inflammation by encephalitogenic cells
T2 - interferon γ induction of nitric oxide synthase and cyclooxygenase 2
AU - Misko, Thomas P.
AU - Trotter, John L.
AU - Cross, Anne H.
PY - 1995/9
Y1 - 1995/9
N2 - Experimental autoimmune encephalomyelitis (EAE) is a T cell-mediated inflammatory demyelinating disorder of the central nervous system (CNS) which serves as a prime animal model for the human disease multiple sclerosis. Previous studies from these laboratories demonstrated excess nitric oxide (NO) in the CNS of EAE-affected mice, and amelioration of EAE with a selective inhibitor of the inducible nitric oxide synthase (iNOS). Recent studies from other laboratories have indicated that prostaglandin PGE2 is increased in CNS tissues of EAE-affected rodents and that EAE is prevented by the inhibition of cyclooxygenase activity. The present study investigated the ability of encephalitogenic lymphoid cells to induce NOS and cyclooxygenase (COX-2) in the murine macrophage line, RAW 264.7. In order to mimic the extracellular milieu present in EAE lesions, conditioned medium (CM) of activated EAE-inducer cells was added to this macrophage line. CM caused a time-dependent increase in nitrite, indicating NO production. Reverse-transcriptase PCR demonstrated iNOS mRNA in RAW 264.7 cells, first detected at 3 h, and Western blots confirmed the induction in RAW cells of the 130-kDa iNOS protein. Production of nitrite by CM-exposed RAW 264.7 cells was blocked by inhibitors of NOS (l-N-methylarginine or aminoguanidine) or by antibodies to murine IFN-γ or IL-1β. CM of activated encephalitogenic cells induced production of PGE2 by RAW 264.7 cells, as determined by ELISA, and Western blots identified the presence of the 70-80-kDa inducible COX (COX-2) protein. Induction of COX-2 could be inhibited by antibody to IFN-γ. Thus, encephalitogenic cells are capable of inducing the expression of the inflammatory enzymes iNOS and COX-2 in a murine macrophage line via the T cell cytokine IFN-γ, alone or in combination with IL-1β.
AB - Experimental autoimmune encephalomyelitis (EAE) is a T cell-mediated inflammatory demyelinating disorder of the central nervous system (CNS) which serves as a prime animal model for the human disease multiple sclerosis. Previous studies from these laboratories demonstrated excess nitric oxide (NO) in the CNS of EAE-affected mice, and amelioration of EAE with a selective inhibitor of the inducible nitric oxide synthase (iNOS). Recent studies from other laboratories have indicated that prostaglandin PGE2 is increased in CNS tissues of EAE-affected rodents and that EAE is prevented by the inhibition of cyclooxygenase activity. The present study investigated the ability of encephalitogenic lymphoid cells to induce NOS and cyclooxygenase (COX-2) in the murine macrophage line, RAW 264.7. In order to mimic the extracellular milieu present in EAE lesions, conditioned medium (CM) of activated EAE-inducer cells was added to this macrophage line. CM caused a time-dependent increase in nitrite, indicating NO production. Reverse-transcriptase PCR demonstrated iNOS mRNA in RAW 264.7 cells, first detected at 3 h, and Western blots confirmed the induction in RAW cells of the 130-kDa iNOS protein. Production of nitrite by CM-exposed RAW 264.7 cells was blocked by inhibitors of NOS (l-N-methylarginine or aminoguanidine) or by antibodies to murine IFN-γ or IL-1β. CM of activated encephalitogenic cells induced production of PGE2 by RAW 264.7 cells, as determined by ELISA, and Western blots identified the presence of the 70-80-kDa inducible COX (COX-2) protein. Induction of COX-2 could be inhibited by antibody to IFN-γ. Thus, encephalitogenic cells are capable of inducing the expression of the inflammatory enzymes iNOS and COX-2 in a murine macrophage line via the T cell cytokine IFN-γ, alone or in combination with IL-1β.
KW - Cyclooxygenase 2
KW - Experimental autoimmune encephalomyelitis
KW - Nitric oxide
UR - http://www.scopus.com/inward/record.url?scp=0028792386&partnerID=8YFLogxK
U2 - 10.1016/0165-5728(95)00091-F
DO - 10.1016/0165-5728(95)00091-F
M3 - Article
C2 - 7593555
AN - SCOPUS:0028792386
SN - 0165-5728
VL - 61
SP - 195
EP - 204
JO - Journal of Neuroimmunology
JF - Journal of Neuroimmunology
IS - 2
ER -