Interleukin 10 transfected into Chinese hamster ovary cells prevents tumor growth and macrophage infiltration.
Expression of cytokines in tumor cells provides a sensitive modality to analyze the consequences of local cytokines in vivo on tumor infiltrating cells and tumorigenicity. We have transfected Chinese hamster ovary (CHO) cells with an interleukin 10 (IL-10) expression vector. CHO-IL10 cells although unaltered with respect to their in vitro growth lost tumorigenicity, both in nude and in SCID mice and in an IL-10 dose dependent manner. In addition, CHO-IL10 cells suppressed the growth of equal numbers of coinjected but not of contralaterally injected CHO cells. Immunohistology with anti-CR3/Mac-1 and anti-Mac-3 monoclonal antibodies revealed that CHO tumors were substantially infiltrated by macrophages. However, in CHO-IL10 tumors macrophages were virtually absent within the tumor tissue. Our results suggest that IL-10 indirectly suppresses tumor growth of certain tumors by inhibiting infiltration of macrophages which may provide tumor growth promoting activity.
Richter
G
G
Institute of Immunology, Klinikum Steglitz, Free University of Berlin, Germany.
Krüger-Krasagakes
S
S
Hein
G
G
Hüls
C
C
Schmitt
E
E
Diamantstein
T
T
Blankenstein
T
T
D000818:Animals; D001483:Base Sequence; D016466:CHO Cells; D006224:Cricetinae; D005260:Female; D015316:Genetic Therapy; D016753:Interleukin-10 / Q000235:genetics* / Q000502:physiology; D008264:Macrophages / Q000473:pathology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009374:Neoplasms, Experimental / Q000473:pathology* / Q000628:therapy; D014162:Transfection
D016753:Interleukin-10