Analyzing classical and alternative macrophage activation in macrophage/neutrophil-specific IL-4 receptor-alpha-deficient mice.
Macrophage activation can be divided into a classical and an alternative pathway. Interferon-gamma-induced, classically activated macrophages are indispensable for protective effector responses against intracellular pathogens. However, excessive inflammatory immune responses mediated by classical macrophage activation can also be detrimental to the host. In contrast, the IL-4 receptor-alpha-mediated alternative pathway of macrophage activation has been proposed as a mechanism to attenuate excessive inflammation. Indeed, the generation of macrophage/neutrophil-specific IL-4 receptor-alpha-deficient mice (LysMcreIL-4Ralphaalpha-/lox) enables us now to evaluate the importance of this type of macrophage activation in vivo. Thus, the analysis of LysMcreIL-4Ralpha-/lox mice and the phenotypic characterization of macrophage activation during inflammatory immune responses become of major importance for inflammation research, and useful markers have been identified that allow classically and alternatively activated macrophages to be distinguished. Inducible nitric oxide synthase and arginase-1 are not only prototypical markers of classical and alternative macrophage activation, but both enzymes are also strongly involved in regulating macrophage effector mechanisms and inflammatory immune responses. In this chapter, we describe the use of LysMcreIL-4Ralpha-/lox mice and present experimental procedures to determine classical versus alternative macrophage activation by analyzing nitric oxide synthase and arginase-1 in vitro and in vivo in this murine model.
Institute for Infectious Diseases and Molecular Medicine and Division of Immunology, Health Science Faculty, University of Cape Town, Cape Town, South Africa.
Frank
F
Brombacher
Berenice
B
Arendse
Reagon
R
Peterson
Alexandra
A
Hölscher
Christoph
C
Hölscher
D000818:Animals; D001119:Arginase; D001120:Arginine / Q000378:metabolism; D001665:Binding Sites; D001947:Breeding; D005838:Genotype; D008262:Macrophage Activation / Q000276:immunology*; D008264:Macrophages / Q000166:cytology / Q000201:enzymology / Q000276:immunology*; D051379:Mice; D008967:Molecular Biology / Q000379:methods*; D009504:Neutrophils / Q000166:cytology / Q000201:enzymology / Q000276:immunology*; D009569:Nitric Oxide / Q000096:biosynthesis; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D010641:Phenotype; D011956:Receptors, Cell Surface / Q000172:deficiency*; D014508:Urea / Q000378:metabolism; D053662:Interleukin-4 Receptor alpha Subunit
D001119:Arginase; D001120:Arginine; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II; D011956:Receptors, Cell Surface; D014508:Urea; C504002:Il4ra protein, mouse; D053662:Interleukin-4 Receptor alpha Subunit