Interleukin 6 gene expression in normal and neoplastic B cells.
In the present report we demonstrate that the IL-6 gene is expressed in anti-Ig-activated and neoplastic B cells. After activation with anti-Ig, splenic B cells rapidly expressed IL-6 mRNA with peak expression occurring at 4 h and declining rapidly thereafter. In an attempt to exclude that the IL-6 mRNA expression was in non-B cells, T cells and monocytes were extensively depleted. In this highly purified B cell population, IL-6 mRNA was retained, whereas the expression of the T cell- and monocyte-restricted CD2 and CD14 genes was nearly undetectable. These results are consistent with the conclusion that activated B cells express IL-6 mRNA. Because we found IL-6 mRNA expression in normal activated B lymphocytes, we examined the expression of IL-6 mRNA in B cell neoplasms. 11 of 25 non-Hodgkins B cell lymphomas and 4 of 4 myelomas and plasma cell leukemias expressed IL-6 mRNA, whereas only 1 of 19 B cell leukemias was positive. To exclude that IL-6 mRNA expression in neoplastic B cells was the result of contaminating non-B cells, T cells and monocytes were extensively depleted from the tumor specimens. In the three IL-6-positive tumor samples depleted of T cells and monocytes, IL-6 mRNA expression was retained in all cases. These observations provide support for the idea that the IL-6 gene is expressed in normal activated and neoplastic B cells.
Freeman
G J
GJ
Division of Tumor Immunology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115.
Freedman
A S
AS
Rabinowe
S N
SN
Segil
J M
JM
Horowitz
J
J
Rosen
K
K
Whitman
J F
JF
Nadler
L M
LM
D000328:Adult; D001402:B-Lymphocytes / Q000032:analysis* / Q000276:immunology; D015152:Blotting, Northern; D002460:Cell Line; D005786:Gene Expression Regulation; D006801:Humans; D015850:Interleukin-6; D007378:Interleukins / Q000235:genetics*; D008213:Lymphocyte Activation; D008228:Lymphoma, Non-Hodgkin / Q000235:genetics* / Q000276:immunology; D012333:RNA, Messenger / Q000302:isolation & purification
D015850:Interleukin-6; D007378:Interleukins; D012333:RNA, Messenger