IL-2 mRNA expression in Tac-positive malignant lymphomas.
Expression of the IL-2 receptor (Tac antigen/CD25) is documented in malignant lymphomas. Because IL-2 is a major lymphocyte growth factor, an IL-2-dependent growth could be involved in the proliferation of Tac-positive lymphomas. Indeed such a mechanism has been demonstrated experimentally for the growth of T-cell lines. To investigate this point in human lymphomas, we used in situ hybridization to analyze the expression of the IL-2 gene in 20 non-Hodgkin's lymphomas, among which 12 expressed the IL-2 receptor. Nine of these were anaplastic large cell lymphomas expressing the Ki-1-related antigen. We here show that IL-2-producing cells are present in all the lymphomas we analyzed. As a mean, there is no significant difference in the percentage of IL-2-producing cells between Tac-positive and -negative lymphomas. However, the level of IL-2 production is highly heterogeneous in both groups, and the highest density of IL-2-producing cells was observed in 2 Tac-positive lymphomas. Simultaneous detection of cellular antigens and of IL-2 mRNA demonstrates that IL-2 is produced by reactive T cells rather than by tumor cells. These results suggest that if IL-2 is involved in the growth of Tac-positive lymphomas, it acts as a paracrine, rather than an autocrine, factor.
Peuchmaur
M
M
INSERM U 131, Hôpital Antoine Béclère, Clamart, France.
Emilie
D
D
Crevon
M C
MC
Solal-Celigny
P
P
Maillot
M C
MC
Lemaigre
G
G
Galanaud
P
P
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005260:Female; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D007376:Interleukin-2 / Q000235:genetics / Q000378:metabolism*; D008223:Lymphoma / Q000276:immunology / Q000378:metabolism* / Q000648:ultrastructure; D008228:Lymphoma, Non-Hodgkin / Q000276:immunology / Q000378:metabolism / Q000648:ultrastructure; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D015375:Receptors, Interleukin-2 / Q000032:analysis / Q000378:metabolism*
D007376:Interleukin-2; D012333:RNA, Messenger; D015375:Receptors, Interleukin-2