Changes and significance of CD8 + CD28 - regulatory T cells in acute phase of Kawasaki disease / 中华微生物学和免疫学杂志

ABSTRACT

Objective:To investigate the changes of CD8 + CD28 - regulatory T cells (Treg) and its role in the pathogenesis of Kawasaki disease (KD). Methods:A total of 48 children with KD were enrolled in the present study from June 2019 to December 2021. Blood samples were collected from them during acute phage of KD and after intravenous immunoglobulin (IVIG) treatment. Another 32 age-matched healthy children were recruited as control group. The proportions of CD8 + CD28 -Treg cells and the expression of programmed cell death protein 1 (PD-1), factor associated suicide ligand (FasL), inducible T-cell co-stimulator ligand (ICOSL), CD80 and CD86 protein were evaluated by flow cytometry. The expression of Helios, perforin, granzyme B, immunoglobulin-like transcript 3 (ILT3) and ILT4 at the transcription level was measured by real-time PCR. Concentrations of IL-10 and TGF-β in the culture supernatants of CD8 + CD28 -Treg cells stimulated with activated CD4 + T cells were measured by ELISA. Results:⑴ The proportions of CD8 + CD28 -Treg cells and the expression of Helios in patients with acute KD were higher than those in the control group ( P<0.05), and reduced remarkably after IVIG therapy ( P<0.05). The two afore-mentioned indexes were lower in patients combined with coronary artery lesion (CAL) than in those without coronary artery lesion (NCAL) ( P<0.05). ⑵ Compared with the control group, the patients with acute KD showed increased expression of FasL, PD-1, ICOSL and perforin in CD8 + CD28 -Treg cells ( P<0.05). The concentrations of IL-10 and TGF-β1 in the culture supernatants of CD8 + CD28 -Treg cells from patients with acute KD were lower than those in the control group after stimulation with activated CD4 + T cells ( P<0.05), which restored to some extent after IVIG treatment ( P<0.05). All of the six above-mentioned indexes in the CAL group were found to be lower than those in the NCAL group ( P<0.05). There were slight differences in granzyme B expression between different groups ( P>0.05). (3) In comparison with the healthy controls, the patients with acute KD showed overexpressed co-stimulatory molecules such as CD80 and CD86 on CD14 + cells ( P<0.05) and up-regulated expression of inhibitory molecules ILT3 and ILT4 ( P<0.05), which were restored remarkably after IVIG treatment ( P<0.05). Furthermore, the expression of CD80 and CD86 at protein level increased in the CAL group than in the NCAL group ( P<0.05), while the expression of ILT3 and ILT4 at transcriptional level decreased in the CAL group ( P<0.05). Conclusions:Relative insufficiency and impaired function of CD8 + CD28 -Treg cells might be one of the important factors resulting in immune dysfunction and vascular damage in KD patients.