Tregs Attenuate Peripheral Oxidative Stress and Acute Phase Proteins in ALS

Abstract

Oxidative stress (OS) induces inflammation, which in turn exacerbates OS and the expression of acute phase proteins (APPs). Regulatory T lymphocyte (Treg) therapy was assessed for suppression of OS and APP responses in longitudinal serum samples from subjects with amyotrophic lateral sclerosis (ALS) enrolled in a phase I clinical trial. The first round of Treg therapy suppressed levels of oxidized low-density lipoprotein (ox-LDL). During a 6-month washout period, ox-LDL levels increased. A second round of therapy again suppressed ox-LDL levels and then rose following the cessation of treatment. Serum levels of APPs, soluble CD14, lipopolysaccharide binding protein, and C-reactive protein, were stabilized during Treg administrations, but rose during the washout period and again after therapy was discontinued. Treg therapy potentially suppresses peripheral OS and the accompanying circulating pro-inflammatory induced APPs, both of which may serve as peripheral candidates for monitoring efficacies of immunomodulating therapies. ANN NEUROL 2022;92:195-200.

FIGURE 1

LOX‐1 and ox‐LDL are elevated in subjects with ALS. A, B. LOX‐1 is increased in the serum of all subjects with ALS, and in rapidly and slowly progressing subjects, when compared with HC. C, D. ox‐LDL is increased in the serum of all subjects with ALS, and in rapidly progressing subjects, when compared with HC. ox‐LDL is not increased in the serum of slowly progressing subjects with ALS compared with HC. The progression rate was determined using the Appel ALS (AALS) scoring system., In this scoring system, less than 1.5 AALS points per month is a slowly progressing subject. Equal to or greater than 1.5 points per month is a rapidly progressing subject. E. LOX‐1 positively correlated with the rate of progression in subjects with ALS. F. ox‐LDL positively correlated with the rate of progression in subjects with ALS. G. LOX‐1 positively correlated with ox‐LDL in the 16 subjects with ALS that were assayed for both LOX‐1 and ox‐LDL. *p < 0.05, **p < 0.001, and n.s. = not significant.

FIGURE 2

A, B. Subjects' clinical statuses reflects the level of the subjects' serum ox‐LDL levels. These subjects were enrolled and completed a phase I clinical trial with Treg + IL‐2 therapy. ox‐LDL levels were suppressed following the first round of Treg infusions, increased during the washout period, were then suppressed during the second round of Treg infusions, and rose following the cessation of Treg + IL‐2 treatment. The stabilization and deterioration of the subject's clinical status mirrored the decline and rise of serum ox‐LDL levels. C. Subject 3, a slowly progressing subject, had stable ox‐LDL serum levels and reflects a stable clinical status. Arrows indicate Tregs + IL‐2 infusion times. IL‐2 was administered 3X/week thoughout the study. The red‐dotted lines demarcate Treg + IL‐2 therapy or IL‐2 only intervals. During the Treg “washout” period, the subjects received IL‐2 injections. Red line = mean value of the ox‐LDL level in HC. Black lines = ± one standard deviation of the ox‐LDL levels in HC.

FIGURE 3

sCD14, LBP, and CRP in the serum of subjects enrolled in a phase 1 Treg + IL‐2 clinical study. A, B. sCD14, LBP, and CRP fell and rose with Treg + IL‐2 treatment. C. sCD14 was unchanged in a slowly progressing subject with ALS. LBP and CRP fell and rose with Treg + IL‐2 treatment. Arrows indicate Tregs + IL‐2 infusion times. IL‐2 was administered 3X/week throughout the study. The red‐dotted lines demarcate Treg + IL‐2 therapy or IL‐2 only intervals. During the Treg “washout” period, the subjects received IL‐2 injections. Red line = mean value of each APP level in HC. Black lines = ±one standard deviation of each APP level in HC.