Malignant chronic lymphocytic leukemia B cells elaborate soluble factors that down-regulate T cell and NK function
✍ Scribed by Jack D. Burton; Carol H. Weitz; Dr. Neil E. Kay
- Publisher
- John Wiley and Sons
- Year
- 1989
- Tongue
- English
- Weight
- 944 KB
- Volume
- 30
- Category
- Article
- ISSN
- 0361-8609
No coin nor oath required. For personal study only.
✦ Synopsis
To determine if the frequently observed T cell and natural killer dysfunction in 8-chronic lymphocytic leukemia might be related to the presence of large numbers of malignant B cells, we studied the effects of secretory or shed products of CLL B cells on normal (control) T cell and NK function. The cell-free supernatants from CLL B cells cultured from 24 to 48 hr inhibited a variety of T cell functions including: PHA-induced proliferation, PHA-stimulated entry of T cells into the cell cycle, and PHA-induced production of interleukin-2. In addition, 8-CLL supernatants diminished control NK activity. Purified control B cells and other malignant cell lines produced little or no inhibitory activity toward these T cell or NK functions. The sera from these same 8-CLL patients diminished PHA-induced interleukin-2 production by control T cells. Initial molecular characterization of the inhibitory factor(s) revealed it to be of low molecular weight (< 5000 daltons) with loss of functional activity after treatment with neuraminidase. This suggested that this substance might be either a ganglioside or glycoprotein whose inhibitory activity depends on the presence of a sialic acid moiety. If CLL B cells are capable of secreting or shedding immunosuppressive factor(s), then alteration of this property may result in a more normal immune system for these patients.