IL-6 mRNA expression in CD25 positive malignant lymphomas.
We recently demonstrated that IL-2 is produced by reactive T cells in CD25-positive malignant lymphomas (ML). Using in situ hybridization, we investigated IL-6 mRNA expression in these CD25-positive ML. The ML tested included 9 anaplastic large cell lymphomas and 3 B-diffuse large cell lymphomas. Five CD25-negative ML were studied as controls. We show that IL-6 producing cells are present in all these ML. The density of positive cells was heterogeneous from case to case. However 3 cases of CD25-positive ML showed a dramatically higher density of IL-6 producing cells (70, 50, 43 producing cells per 10,000 cells, respectively) as compared to the other 9 cases of CD25-positive ML (mean 6.03 +/- 2.1 per 10,000). Morphological and topographical data suggested that several types of cells including fibroblasts, lymphocytes, macrophages and endothelial cells may synthesize IL-6. A combination of immunohistochemistry and in situ hybridization showed that reactive T cells and endothelial cells express the IL-6 gene whereas CD30-positive ML cells do not express this gene. Previous studies showed that IL-6 was capable to induce IL-2 receptor expression as well as production of IL-2 and stimulation of lymphomatous cells growth. Our present results indicate that the paracrine production of this cytokine may play a role in the proliferation of malignant lymphomas.
Diebold
S
S
Service d'Anatomie Pathologique, Hôpital Antoine Béclère, Clamart, France.
Peuchmaur
M
M
Emilie
D
D
Crevon
M C
MC
Solal-Celigny
P
P
Tertian
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 / Q000096:biosynthesis; D015850:Interleukin-6 / Q000096:biosynthesis* / Q000235:genetics; D016403:Lymphoma, Large B-Cell, Diffuse / Q000235:genetics / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D015375:Receptors, Interleukin-2
D007376:Interleukin-2; D015850:Interleukin-6; D012333:RNA, Messenger; D015375:Receptors, Interleukin-2