Interferon-α mediating the functional damage of CD56dimCD57+natural killer cells in peripheral blood of systemic lupus erythematosuss / 北京大学学报(医学版)

OBJECTIVE@#To investigate the regulatory effect of interferon-α (IFN-α) on the apoptosis and killing function of CD56dimCD57+ natural killer (NK) cells in systemic lupus erythematosus (SLE) patients, and to explore the specific mechanism.@*METHODS@#A total of sixty-four newly treated SLE patients and sixteen healthy controls (HC) enrolled in the Second Hospital of Dalian Medical University were selected as the research subjects. And the gene expression levels of molecules related to NK cell-killing function were detected by real-time quantitative polymerase chain reaction. CD56dimCD57+ NK cells were co-cultured with the K562 cells, and the apoptotic K562 cells were labeled with Annexin-Ⅴ and 7-amino-actinomycin D. Peripheral blood mononuclear cells were treated with 20, 40, and 80 μmol/L hydrogen peroxide (H2O2), and treated without H2O2 as control, the expression level of perforin (PRF) was detected by flow cytometry. The concentration of IFN-α in serum was determined by enzyme linked immunosorbent assay. The expression levels of IFN-α receptors (IFNAR) on the surface of CD56dimCD57+ NK cells were detected by flow cytometry, and were represented by mean fluorescence intensity (MFI). CD56dimCD57+ NK cells were treated with 1 000 U/mL IFN-α for 24, 48 and 72 h, and no IFN-α treatment was used as the control, the apoptosis and the expression levels of mitochondrial reactive oxygen species (mtROS) were measured by flow cytometry and represented by MFI.@*RESULTS@#Compared with HC(n=3), the expression levels of PRF1 gene in peripheral blood NK cells of the SLE patients (n=3) were decreased (1.24±0.41 vs. 0.57±0.12, P=0.05). Compared with HC(n=5), the ability of peripheral blood CD56dimCD57+ NK cells in the SLE patients (n=5) to kill K562 cells was significantly decreased (58.61%±10.60% vs. 36.74%±6.27%, P < 0.01). Compared with the control (n=5, 97.51%±1.67%), different concentrations of H2O2 treatment significantly down-regulated the PRF expression levels of CD56dimCD57+ NK cells in a dose-dependent manner, the 20 μmol/L H2O2 PRF was 83.23%±8.48% (n=5, P < 0.05), the 40 μmol/L H2O2 PRF was 79.53%±8.56% (n=5, P < 0.01), the 80 μmol/L H2O2 PRF was 76.67%±7.16% (n=5, P < 0.01). Compared to HC (n=16), the serum IFN-α levels were significantly increased in the SLE patients (n=45) with moderate to high systemic lupus erythematosus disease activity index (SLEDAI≥10) [(55.07±50.36) ng/L vs. (328.2±276.3) ng/L, P < 0.001]. Meanwhile, compared with HC (n=6), IFNAR1 expression in peripheral blood CD56dimCD57+ NK cells of the SLE patients (n=6) were increased (MFI: 292.7±91.9 vs. 483.2±160.3, P < 0.05), and compared with HC (n=6), IFNAR2 expression in peripheral blood CD56dimCD57+ NK cells of the SLE patients (n=7) were increased (MFI: 643.5±113.7 vs. 919.0±246.9, P < 0.05). Compared with control (n=6), the stimulation of IFN-α (n=6) significantly promoted the apoptosis of CD56dimCD57+ NK cells (20.48%±7.01% vs. 37.82%±5.84%, P < 0.05). In addition, compared with the control (n=4, MFI: 1 049±174.5), stimulation of CD56dimCD57+ NK cells with IFN-α at different times significantly promoted the production of mtROS in a time-dependent manner, 48 h MFI was 3 437±1 472 (n=4, P < 0.05), 72 h MFI was 6 495±1 089 (n=4, P < 0.000 1), but there was no significant difference at 24 h of stimulation.@*CONCLUSION@#High serum IFN-α level in SLE patients may induce apoptosis by promoting mtROS production and inhibit perforin expression, which can down-regulate CD56dimCD57+ NK killing function.

Inmunopatogenia de la arteritis de la temporal / Immunopathogenesis of temporal arteritis

La arteritis de la temporal, clasificada como una vasculitis que compromete vasos de gran y mediano calibre, debe ser considerada como una emergencia médica, dado el potencial de causar ceguera y accidentes vasculares. La lesión típica corresponde a granulomas en la pared vascular, los que están constituidos por macrófagos y célulasT CD4+. Éstos se activan en la adventicia, luego de interactuar con las células dendríticas nativas. La injuria tisular es mediada por diversos subtipos de macrófagos, los que ejercen las diferentes funciones efectoras. El daño que domina en la capa media resulta del estrés oxidativo y determina la apoptosis de las células musculares lisas y la nitración de las endoteliales. Por otro lado, factores de crecimiento derivados de macrófagos determinan la hiperplasia intimal y la consecuente oclusión luminal. Las manifestaciones clínicas se relacionan estrechamente con el sitio isquémico. El tratamiento de elección son los corticoides sistémicos, los cuales pueden asociarse a inmunosupresores como también con agentes biológicos.

Temporal arthritis, which is classified as a large-and medium-caliber vessel vasculitis, should be considered as a medical emergency, given its potential to cause blindness and strokes. The injury typically corresponds to granulomas in the vascular wall, which are composed of macrophages and CD4+ T cells. They are activated in the adventitia, after interacting with native dendritic cells. Immunopathological mechanisms involve different subtypes of macrophaesges, which exert different effector functions. Damage that prevails within the median layer is secondary to oxidative stress and triggers apoptosis of smooth muscle cells and nitration of endothelial cells. On the other hand, growth factors derived from macrophages determine intimal hyperplasia and subsequent luminal occlusion. Clinical manifestations are closely related to the ischemic site. The treatment of choice is systemic corticosteroids, which can be associated with immunosuppressive drugs as well as biological agents.

Derivation of leukemic plasmacytoid dendritic cells coexpressing a progenitor cell surface antigen, CD117, without interferon-alpha production.

CD4+CD56+ lineage negative malignancy has recently been considered as plasmacytoid dendritic cell (PDC) leukemia/lymphoma. We investigated immunophenotypic and functional characterizations of PDC leukemic cells in one case. Lineage markers were all negative except partially positive CD11c and positive CD117, indicating malignant cells were leukemic PDCs coexpressing myeloid and progenitor cell surface antigens. Leukemic PDCs cultured with IL-3 increased in size and expression of CD11c, CD40 and HLA-DR, although the cells cultured with IL-2 or GM-CSF showed little proliferation. Furthermore, CD40 ligation after IL-3 stimulation yielded morphological changes such as expression of dendritic process. These findings showed that malignant cells were consistent with leukemic PDCs. However, secretion of interferon-alpha was not detected in leukemic PDCs with the stimulation of CpG ODN or inactivated herpes simplex virus-1.

Expression and biological activity of two recombinant polypeptides related to subunit 1 of the interferon-alpha receptor

Abnormal production of interferon alpha (IFN-a) has been found in certain autoimmune diseases and can be also observed after prolonged therapy with IFN-a. IFN-a can contribute to the pathogenesis of allograft rejection in bone marrow transplants. Therefore, the development of IFN-a inhibitors as a soluble receptor protein may be valuable for the therapeutic control of these diseases. We have expressed two polypeptides encoding amino acids 93-260 (P1) and 261-410 (P2) of the extracellular domain of subunit 1 of the interferon-a receptor (IFNAR 1-EC) in E. coli. The activities of the recombinant polypeptides and of their respective antibodies were evaluated using antiproliferative and antiviral assays. Expression of P1 and P2 polypeptides was achieved by transformation of cloned plasmid pRSET A into E. coli BL21(DE3)pLysS and by IPTG induction. P1 and P2 were purified by serial sonication steps and by gel filtration chromatography with 8 M urea and refolded by dialysis. Under reducing SDS-PAGE conditions, the molecular weight of P1 and P2 was 22 and 17 kDa, respectively. Polyclonal anti-P1 and anti-P2 antibodies were produced in mice. P1 and P2 and their respective polyclonal antibodies were able to block the antiproliferative activity of 6.25 nM IFN-aB on Daudi cells, but did not block IFN-aB activity at higher concentrations (>6.25 nM). On the other hand, the polypeptides and their respective antibodies did not inhibit the antiviral activity of IFN-aB on Hep 2/c cells challenged with encephalomyocarditis virus.

Immunomodulación en la práctica pediátrica / Immunomodulation in pediatric practice

En los últimos años la inmunoterapia ha tomado un gran auge debido, primordialmente, a la variedad de alternativas descritas, fundamentadas en una gran cantidad de estudios clínicos, lo que ha permitido que enfermedades aparentemente poco complicadas, pero cuya resolución es frecuentemente problemática, como las infecciones recurrentes de las vías respiratorias, hasta enfermedades crónicas como tuberculosis, lepra, colagenopatías y enfermedades malignas, etc., ahora puedan tener un mejor pronostico. Es importante resaltar la importancia de conocer las características farmacologicas de estos medicamentos, así como sus indicaciones precisas. con el fin de no caer en el mal uso de los mismos y poder ofrecer a los pacientes un recurso valioso y eficaz de cara al nuevo milenio