Lymphoid Aggregates in the CNS of Progressive Multiple Sclerosis Patients Lack Regulatory T Cells
FRONTIERS IN IMMUNOLOGY
Authors: Bell, Luisa; Lenhart, Alexander; Rosenwald, Andreas; Monoranu, Camelia M.; Berberich-Siebelt, Friederike
Abstract
In gray matter pathology of multiple sclerosis, neurodegeneration associates with a high degree of meningeal inflammatory activity. Importantly, ectopic lymphoid follicles (eLFs) were identified at the inflamed meninges of patients with progressive multiple sclerosis. Besides T lymphocytes, they comprise B cells and might elicit germinal center (GC)-like reactions. GC reactions are controlled by FOXP3(+) T-follicular regulatory cells (T-FR), but it is unknown if they participate in autoantibody production in eLFs. Receiving human post-mortem material, gathered from autopsies of progressive multiple sclerosis patients, indeed, distinct inflammatory infiltrates enriched with B cells could be detected in perivascular areas and deep sulci. CD35(+) cells, parafollicular CD138(+) plasma cells, and abundant expression of the homing receptor for GCs, CXCR5, on lymphocytes defined some of them as eLFs. However, they resembled GCs only in varying extent, as T cells did not express PD-1, only few cells were positive for the key transcriptional regulator BCL-6 and ongoing proliferation, whereas a substantial number of T cells expressed high NFATc1 like GC-follicular T cells. Then again, predominant cytoplasmic NFATc1 and an enrichment with CD3(+)CD27(+) memory and CD4(+)CD69(+) tissue-resident cells implied a chronic state, very much in line with PD-1 and BCL-6 downregulation. Intriguingly, FOXP3(+) cells were almost absent in the whole brain sections and CD3(+)FOXP3(+) T(FR)s were never found in the lymphoid aggregates. This also points to less controlled humoral immune responses in those lymphoid aggregates possibly enabling the occurrence of CNS-specific autoantibodies in multiple sclerosis patients.
Oleanolic acid exerts inhibitory effects on the late stage of osteoclastogenesis and prevents bone loss in osteoprotegerin knockout mice
JOURNAL OF CELLULAR BIOCHEMISTRY
Authors: Zhao, Dongfeng; Shu, Bing; Wang, Chenglong; Zhao, Yongjian; Cheng, Weidong; Sha, Nannan; Li, Chenguang; Wang, Qang; Lu, Sheng; Wang, Yongjun
Abstract
Postmenopausal women undergo rapid bone loss, which caused by the accelerated osteoclastic bone resorption. Receptor activator of nuclear factor kappa-B ligand (RANKL) plays critical and essential roles on varied stages of osteoclastogenesis. Oleanolic acid (OA), a naturally derived small compound, has been found suppress osteoclastogenesis in early stage of bone marrow macrophages (BMMs). However, whether OA also regulates the late stage of osteoclastogenesis remains unclear. Here, the regulatory effect of OA on the late stage of osteoclastogenesis was investigated in vitro using RANKL-pretreated BMMs and in vivo using osteoprotegerin (OPG) knockout mice. Our in vitro studies demonstrate that OA inhibits the late stage of osteoclastogenesis from RANKL-pretreated BMMs. For in vivo animal investigation, OA attenuates the bone loss phenotypes in OPG-knockout mice by decreasing the densities of osteoclast, which are in consistent with the finding with in vitro osteoclastogenesis. Mechanistic investigations found that OA largely inhibit the activity of c-Fos and Nuclear factor of activated T-cells c1 (NFATc1) with RANKL-pretreated BMMs and OPG-knockout mice. Furthermore, OA suppresses the activities of osteoclast genes, such as Tartrate resistant acid phosphatase (TRAP), CathepsinK (Ctsk), and Matrix metalloproteinase 9 (MMP9). Taken together these findings, they have not only defined an inhibitory effect of OA in the late stage of osteoclastogenesis but have also gained new molecular mechanisms underlying the process of osteoclast formation.