Adverse effects of Gulf War Illness (GWI) serum on neural cultures and their prevention by healthy serum

Abstract

Gulf War Illness (GWI) is a chronic debilitating disease of unknown etiology that affects the brain and has afflicted many veterans of the 1990-91 Gulf War (GW). Here we tested the hypothesis that brain damage may be caused by circulating harmful substances to which GW veterans were exposed but which could not be eliminated due to lack of specific immunity. We assessed the effects of serum from GWI patients on function and morphology of brain cultures in vitro, including cultures of embryonic mouse brain and neuroblastoma N2A line. Blood serum from GWI and healthy GW veterans was added, alone and in combination, to the culture and its effects on the function and morphology of the culture assessed. Neural network function was assessed using electrophysiological recordings from multielectrode arrays in mouse brain cultures, whereas morphological assessments (neural growth and cell apoptosis) were done in neuroblastoma cultures. In contrast to healthy serum, the addition of GWI serum disrupted neural network communication and caused reduced cell growth and increased apoptosis. All of these detrimental effects were prevented or ameliorated by the concomitant addition of serum from healthy GW veterans. These findings indicate that GWI serum contains neuropathogenic factors that can be neutralized by healthy serum. We hypothesize that these factors are persistent antigens circulating in GWI blood that can be neutralized, possibly by specific antibodies present in the healthy serum, as proposed earlier¹.

Keywords: Apoptosis; Blood serum; Brain cultures; Gulf War Illness; Multielectrode arrays; Neural growth.

Figure 1.

A, mean ± SEM coefficient of variation in MEAs for the 3 treatments (Table 1B). N = 3 for control, N = 4 for GWI, and N = 4 for GWI+Control. B, median coefficient of variation from the bootstrap analysis ± 99% confidence intervals. (Table 2; see text for details.)

Figure 2.

Representative fields of Neuro 2A cells cultured for 2 days in the presence of control (healthy serum, participant C1), GWI serum (participant G2), and healthy and GWI serum combination (C1+G2). Horizontal bars are 200 μm.

Figure 3.

A, mean ± SEM percent cell spreading in the 3 treatments. N = 30 measurements for Control, 45 for GWI, and 35 for GWI+Control. B, mean ± SEM percent cell apoptosis (TUNEL assay) in the 3 treatments. N = 17 measurements for Control, 28 for GWI, and 26 for GWI+Control.