Skewing the Th cell phenotype toward Th1 alters the maturation of tumor-infiltrating mononuclear phagocytes.
Mononuclear phagocytes (MPCs) at the tumor site can be divided into subclasses, including monocyte-lineage myeloid-derived suppressor cells (MDSCs) and the immunosuppressive tumor-infiltrating macrophages (TIMs). Cancer growth coincides with the expansion of MDSCs found in the blood, secondary lymphoid organs, and tumor tissue. These MDSCs are thought to mature into macrophages and to promote tumor development by a combination of growth-enhancing properties and suppression of local antitumor immunoresponses. As little is known about either subset of MPCs, we investigated MPCs infiltrating into murine adenocarcinoma MCA38 tumors. We found that these MPCs displayed immunosuppressive characteristics and a MDSC cell-surface phenotype. Over 70% of the MPCs were mature (F4/80(+)Ly6C(-)) macrophages, and the rest were immature (F480(+) Ly6C(+)) monocytes. MPC maturation was inhibited when the cells infiltrated a tumor variant expressing IL-2 and soluble TNF type II receptor (sTNFRII). In addition, the IL-2/sTNFRII MCA38 tumor microenvironment altered the MPC phenotype; these cells did not survive culturing in vitro as a result of Fas-mediated apoptosis and negligible M-CSFR expression. Furthermore, CD4(+) tumor-infiltrating lymphocytes (TILs) in wild-type tumors robustly expressed IL-13, IFN-gamma, and GM-CSF, and CD4(+) TILs in IL-2/sTNFRII-expressing tumors expressed little IL-13. These data suggest that immunotherapy-altered Th cell balance in the tumor microenvironment can affect the differentiation and maturation of MPCs in vivo. Furthermore, as neither the designation MDSC nor TIM can sufficiently describe the status of monocytes/macrophages in this tumor microenvironment, we believe these cells are best designated as MPCs.
Departments of Surgical Oncology, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu, 501-1194, Japan.
Kenichi
K
Nonaka
Masanao
M
Saio
Tatsuhiko
T
Suwa
Alan B
AB
Frey
Naoki
N
Umemura
Hisashi
H
Imai
Guan-Feng
GF
Ouyang
Shinji
S
Osada
Margit
M
Balazs
Roza
R
Adany
Yoshihiro
Y
Kawaguchi
Kazuhiro
K
Yoshida
Tsuyoshi
T
Takami
D000230:Adenocarcinoma / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D000818:Animals; D017209:Apoptosis / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000276:immunology; D003110:Colonic Neoplasms / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D053222:Fas Ligand Protein / Q000502:physiology; D005434:Flow Cytometry; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D015151:Immunoblotting; D007124:Immunoenzyme Techniques; D016130:Immunophenotyping; D007371:Interferon-gamma / Q000276:immunology / Q000378:metabolism; D018793:Interleukin-13 / Q000276:immunology / Q000378:metabolism; D007376:Interleukin-2 / Q000276:immunology / Q000378:metabolism; D016246:Lymphocytes, Tumor-Infiltrating / Q000276:immunology* / Q000473:pathology; D008264:Macrophages / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009000:Monocytes / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D022423:Myeloid Cells / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016186:Receptor, Macrophage Colony-Stimulating Factor / Q000235:genetics / Q000378:metabolism; D047888:Receptors, Tumor Necrosis Factor, Type I / Q000502:physiology; D047889:Receptors, Tumor Necrosis Factor, Type II / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015996:Survival Rate; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology
D053222:Fas Ligand Protein; D018793:Interleukin-13; D007376:Interleukin-2; D012333:RNA, Messenger; D047888:Receptors, Tumor Necrosis Factor, Type I; D047889:Receptors, Tumor Necrosis Factor, Type II; C506236:Tnfrsf1a protein, mouse; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D016186:Receptor, Macrophage Colony-Stimulating Factor