Interleukin 4 and 6 Receptor Expression on B Cell Lines and the Lymphocytes of Patients with B Cell Malignancies

Abstract

Interleukin 4 and 6 are important B cell growth factors. Dysregulation of the production of these factors or the expression of their receptors may play an important role in the pathogenesis of various B cell neoplasms. Single cell analysis of cytokine receptor expression on cells from patients with B cell neoplasms using fluorescent labelled interleukins was performed to determine the distribution of the Interleukin 4 receptor (IL-4R) and the Interleukin 6 receptor (IL-6R) on peripheral blood lymphocytes from these patients. Low levels of IL-4R expression (<4%) were found on the peripheral blood lymphocytes of 3 patients with B-CLL and 7 patients with treated myeloma. Higher levels of IL4-R expression were detected on the lymphocytes of a patient with untreated myeloma (8.4%), a patient with prolymphocytic leukaemia (PLL) (83.3%) and on circulating non-Hodgkin's lymphoma cells (48.6%, 13.8% and 5.1%). IL-6R expression was present but IL-4R expression was absent on a number of plasma cell and other B cell lines. The percentage of peripheral blood lymphocytes with IL-6R was reduced in both treated and untreated patients with myeloma (8.2%; n = 32) and MGUS (7.5%; n = 4) but increased in plasmacytoma (24.6%; n = 2), PLL (31%; n = 2) and B-CLL (81%; n = 4) when compared with a normal control group (13.2%; n = 6). The use of fluorescent labelled interleukins provides a valuable new approach to the analysis of the regulators of haemopoietic differentiation.

Key Words:

• Interleukin 6
• Interleukin 4
• B-lymphocytes
• receptors
• antigen
• B-cells