Fluctuations of T- and B-cell subsets in basic protein-induced experimental allergic encephalomyelitis (EAE) in long-tailed macaques

Abstract

Experimental allergic encephalomyelitis (EAE) was induced in long-tailed macaques ( Macaca fascicularis) by inoculation of autologous myelin basic protein (BP) in complete Freund's adjuvant. Natural killer (NK) cell activity and lymphocyte subsets detected by one- and two-color immunofluorescence were monitored longitudinally in these animals. A decrease in NK cell activity was detected at the onset of clinically defined disease. During the preclinical phase of EAE (5–7 days before the onset of clinical signs) the absolute number of T helper (CD4 +) and T suppressor (CD8 +) cells in the peripheral blood decreased significantly. Analysis of peripheral blood B cells revealed a selective depletion of IgD + B cells and a corresponding increase in the number of IgD − B cells prior to and during the onset of clinical signs. Total B-cell numbers were not significantly different between EAE and normal groups. The increased proportion of IgD − B cells in BP-sensitized animals corresponded with the appearance of high titers of circulating anti-BP antibodies. Thus two-color analysis of B-cell subsets may be a sensitive indicator of B-cell activation and of abnormal immune status in EAE. Changes in lymphocyte subsets in macaques with EAE are compared with those in humans with multiple sclerosis.