OBJECTIVES: I. Determine the response rate in patients with low-grade, mantle cell, or follicular B-cell lymphoma treated with a combination of rituximab and low-dose interleukin-2 (IL-2). II. Determine the maximum tolerated dose of IL-2 when given in conjunction with rituximab in this patient population. III. Assess whether antibody dependent cellular cytotoxicity (ADCC) is enhanced by in vivo exposure to IL-2 and whether ADCC activity correlates with clinical response in these patients. IV. Assess the incidence of antirituximab antibody formation in these patients.