Natural killer function in B-chronic lymphocytic leukemia

Abstract

Previous work has demonstrated that large granular lymphocytes (LGL) may be suppressive for B cell function. We have investigated the impact of blood LGL from B-CLL patients with and without hypogammaglobulinemia on normal B cell Ig synthesis and proliferation. Purified blood LGL from controls (age and sex matched) and B-CLL patients were added in various concentrations to isolated normal B cells. The cell co-cultures plus mitogens were incubated at 37 degrees C for 5-7 days and both Ig levels in culture supernatants or cell proliferation determined by ELISA or thymidine incorporation respectively. Percoll purified LGL from controls and B-CLL patients were evaluated for their effect on both PWM and anti-Ig/staph protein A (SPA) induced B-cell proliferation. CLL LGL from certain patients were significantly down regulatory only for anti-Ig/SPA induced B cell proliferation. These B-CLL patients were patients with obvious hypogammaglobulinemia. Subsequently, we purified blood LGL subsets from 5-CLL patients with and without hypogammaglobulinemia. Two LGL subsets; CD16+, CD3- and CD16+, CD3+ were purified by flow cytometry. These LGL were then added to control B cells in presence of PWM and Ig levels determined at day 5 of culture. CLL LGL (CD16+, CD3-) from 3 B-CLL patients with hypogammaglobulinemia were clearly down regulatory for Ig levels. The LGL from 3 B-CLL patients with normal serum Ig levels were not suppressive of mitogen induced B cell Ig synthesis/secretion, nor were the LGL (CD16+, CD3- or CD16+, CD3+) from age and sex matched controls (n = 2).(ABSTRACT TRUNCATED AT 250 WORDS)