Leukocyte Migration and Inflammation CHAPTER 15 355 CD4+ THl cell NK cell CD8+ Tc cell gamma(iFN-y) CD4+ TH2 cell Macrophage Dendritic cell NK cell B cell raton ↑ Differenti L Production of class II MHC class II mhc activity ↑ Antibody -4 and il-5 molecules ↑ Microbicidal d igg1) MA. URE15-15 Summary of pleiotropic activity of inteferon gamma NK cells, and Tc cells and acts on numerous cell y pes. Adapted from y). The activation of macrophages induced by IFN-y plays a crit- Research News, 1993, Science 259: 1693) cal role in chronic inflammation. This cytokine is secreted by TH1 cells, Growing IGURE 15-16 Biological activities of TNF-a(a)A cancerous tu- (b)Transgenic mouse(top)bearing a TNF-a transgene becomes mor in a mouse injected with endotoxin(left) shows hemorrhagic anorectic and severely wasted. Normal mouse is shown on the bo necrosis, unlike a tumor in an untreated mouse(right). Endotoxin in- tom. Part(a)from L. J Old, 1988, Sci. Am. 258: 59: part(b) from duces the production of TNF-cx, which then acts to destroy the tumor. B. Beutler, 1993, Hosp. Prac. (April 15): 45)Leukocyte Migration and Inflammation CHAPTER 15 355 ↓ Proliferation ↓ Production of IL-4 and IL-5 ↑ Expression of class II MHC molecules ↑ Microbicidal activity ↑ Cytotoxic activity ↑ Differentiation ↑ Antibody production (↑ IgG2a; ↓ IgE and IgG1) CD4+ TH2 cell Macrophage B cell ↑ Expression of class II MHC molecules Dendritic cell NK cell CD4+ T NK cell H1 cell CD8+ TC cell Interferon gamma (IFN-γ) FIGURE 15-15 Summary of pleiotropic activity of interferon gamma (IFN-). The activation of macrophages induced by IFN- plays a criti￾cal role in chronic inflammation. This cytokine is secreted by TH1 cells, NK cells, and TC cells and acts on numerous cell types. [Adapted from Research News, 1993, Science 259:1693.] (a) Treated Untreated Necrotic tumor Growing tumor (b) FIGURE 15-16 Biological activities of TNF-. (a) A cancerous tu￾mor in a mouse injected with endotoxin (left) shows hemorrhagic necrosis, unlike a tumor in an untreated mouse (right). Endotoxin in￾duces the production of TNF-, which then acts to destroy the tumor. (b) Transgenic mouse (top) bearing a TNF- transgene becomes anorectic and severely wasted. Normal mouse is shown on the bot￾tom. [Part (a) from L. J. Old, 1988, Sci. Am. 258:59; part (b) from B. Beutler, 1993, Hosp. Prac. (April 15):45.]