scholarly journals Deficiency of the Cyclin Kinase Inhibitor p21(WAF-1/CIP-1) Promotes Apoptosis of Activated/Memory T Cells and Inhibits Spontaneous Systemic Autoimmunity

2004 ◽  
Vol 199 (4) ◽  
pp. 547-557 ◽  
Author(s):  
Brian R. Lawson ◽  
Roberto Baccala ◽  
Jianxun Song ◽  
Michael Croft ◽  
Dwight H. Kono ◽  
...  
Keyword(s):  
Cell Cycle ◽  
B Cells ◽  
Lupus Erythematosus ◽  
Kinase Inhibitors ◽  
Kinase Inhibitor ◽  
Cyclin Dependent Kinase ◽  
Systemic Autoimmunity ◽  
Novel Approach ◽  
Proliferation And Apoptosis ◽  
Cell Cycle Pathway

A characteristic feature of systemic lupus erythematosus is the accumulation of activated/memory T and B cells. These G0/G1-arrested cells express high levels of cyclin-dependent kinase inhibitors such as p21, are resistant to proliferation and apoptosis, and produce large amounts of proinflammatory cytokines. Herein, we show that ablation of p21 in lupus-prone mice allows these cells to reenter the cell cycle and undergo apoptosis, leading to autoimmune disease reduction. Absence of p21 resulted in enhanced Fas/FasL-mediated activation-induced T cell death, increased activation of procaspases 8 and 3, and loss of mitochondrial transmembrane potential. Increased apoptosis was also associated with p53 up-regulation and a modest shift in the ratio of Bax/Bcl-2 toward the proapoptotic Bax. Proliferation and apoptosis of B cells were also increased in p21−/− lupus mice. Thus, modulation of the cell cycle pathway may be a novel approach to reduce apoptosis-resistant pathogenic lymphocytes and to ameliorate systemic autoimmunity.

Primitive Hematopoietic Cells Resist HIV-1 Infection Via P21Waf1/Cip1/Sdi1.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 490-490
Author(s):  
Jie Lin Zhang ◽  
Clyde S. Crumpacker ◽  
David T. Scadden
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Kinase Inhibitors ◽  
Kinase Inhibitor ◽  
Hematopoietic Cells ◽  
Surrogate Marker ◽  
Dependent Manner ◽  
Cyclin Dependent Kinase ◽  
Hematopoietic Stem ◽  
Hiv 1

Abstract Hematopoietic stem cells are resistant to HIV-1 infection. We have identified a novel mechanism by which the cyclin-dependent kinase inhibitor, p21Waf1/Cip1/Sdi1 (p21), known for its regulation of stem cell pool size (1,2), restricts HIV-1 infection of primitive hematopoietic cells in a non-cell cycle dependent manner. Knocking down p21 by siRNA increased HIV-1 infection and induction of p21 expression by phorbol ester (TPA) blocked HIV-1 replication. P21 did not affect the overall levels of cDNA synthesis, but significantly blocked viral integration and resulted in marked increase in 2-LTR circles, a surrogate marker of abortive integration. Consistent with these observations, p21 coimmunoprecipitated with viral integrase and both were detected in the preintegration complex (PIC). Furthermore, silencing p27Kip1 and p18INK4C, cyclin dependent kinase inhibitors related to p21 that affect cell cycle, revealed no impact on viral DNA integration. A closely related dual-tropic lentivirus with a distinct integrase, SIVmac-251 and the other cell-intrinsic inhibitors of HIV-1, Trim5a, PML, Murr1, and IFN-a were unaffected by p21. These results indicate a new function for p21, participating in prevention of HIV integration into the cellular genome. Therefore p21 is an endogenous cellular component in stem cells that provides a unique molecular barrier to HIV-1 infection and may explain the basis for these cells being an uninfected ‘sanctuary’ in HIV disease.

Developmental regulation of a cyclin-dependent kinase inhibitor controls postembryonic cell cycle progression in Caenorhabditis elegans

Development ◽  
1998 ◽  
Vol 125 (18) ◽  
pp. 3585-3597 ◽  
Author(s):  
Y. Hong ◽  
R. Roy ◽  
V. Ambros
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Kinase Inhibitors ◽  
Kinase Inhibitor ◽  
Developmental Regulation ◽  
Ectopic Expression ◽  
Cyclin Dependent Kinase ◽  
Cycle Progression ◽  
Environmental Signals ◽  
C Elegans

C. elegans cki-1 encodes a member of the CIP/KIP family of cyclin-dependent kinase inhibitors, and functions to link postembryonic developmental programs to cell cycle progression. The expression pattern of cki-1::GFP suggests that cki-1 is developmentally regulated in blast cells coincident with G1, and in differentiating cells. Ectopic expression of CKI-1 can prematurely arrest cells in G1, while reducing cki-1 activity by RNA-mediated interference (RNAi) causes extra larval cell divisions, suggesting a role for cki-1 in the developmental control of G1/S. cki-1 activity is required for the suspension of cell cycling that occurs in dauer larvae and starved L1 larvae in response to environmental signals. In vulva precursor cells (VPCs), a pathway of heterochronic genes acts via cki-1 to maintain VPCs in G1 during the L2 stage.

p19INK4d: More than Just a Cyclin-Dependent Kinase Inhibitor

2019 ◽  
Vol 21 (1) ◽  
pp. 96-102
Author(s):  
Xu Han ◽  
Yijin Kuang ◽  
Huiyong Chen ◽  
Ting Liu ◽  
Ji Zhang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Drug Target ◽  
Kinase Inhibitors ◽  
Kinase Inhibitor ◽  
Cell Cycle Regulators ◽  
Cyclin Dependent Kinase ◽  
Disease Treatment ◽  
Cyclin Dependent Kinase Inhibitor ◽  
Damage Repair

Cyclin-dependent kinase inhibitors (CDKIs) are important cell cycle regulators. The CDKI family is composed of the INK4 family and the CIP/KIP family. p19INK4d belongs to the INK4 gene family and is involved in a series of normal physiological activities and the pathogenesis of diseases. Many factors play regulatory roles in the p19INK4d gene expression at the transcriptional and posttranscriptional levels. p19INK4d not only regulates the cell cycle but also plays regulatory roles in apoptosis, DNA damage repair, cell differentiation of hematopoietic cells, and cellular senescence. In this review, the regulatory network of the p19INK4d gene expression and its biological functions are summarized, which provides a basis for further study of p19INK4d as a drug target for disease treatment.

scholarly journals An intrinsic B cell defect is required for the production of autoantibodies in the lpr model of murine systemic autoimmunity.

1991 ◽  
Vol 173 (6) ◽  
pp. 1441-1449 ◽  
Author(s):  
E S Sobel ◽  
T Katagiri ◽  
K Katagiri ◽  
S C Morris ◽  
P L Cohen ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cell ◽  
B Cells ◽  
Lupus Erythematosus ◽  
Immunofluorescence Assay ◽  
Total Serum ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cell Phenotype ◽  
Autoantibody Production ◽  
Systemic Autoimmunity

Mice homozygous for the gene lpr develop marked lymphadenopathy and a spectrum of autoantibodies closely resembling that of human systemic lupus erythematosus. The unusual T cell phenotype of the expanded lymphocyte population and the T-dependence of several antibodies in this strain have suggested that primary T cell abnormalities underlie the autoimmune syndrome. Using double chimeras, we now show that expression of the lpr gene in B cells is absolutely necessary for autoantibody production. Combinations of anti-Thy 1.2 + C' treated bone marrow from congenic strains of C57BL/6 mice, differing only at the immunoglobulin heavy chain (Igh) and lpr loci, were transferred into lethally irradiated B6/lpr mice. Double chimerism was documented by allotype-specific surface IgD and IgM immunofluorescence assay of peripheral blood and by allotype-specific enzyme-linked immunosorbent assay for total IgM in serum. Despite the presence of both +/+ and lpr B cells, IgM and IgG2a anti-chromatin as well as IgM anti-IgG were entirely the products of lpr B cells. Total serum IgG2a and IgG1 were also dominated by the lpr phenotype but not to the same extent. A similar experiment using B6/lpr-Igha recipients confirmed these findings. Additional experiments in which B6/lpr recipients were infused with ratios of donor bone marrow favoring B6.C20 +/+ over B6/lpr showed that even though +/+ B cells were overrepresented, autoantibodies were only of the lpr allotype. In addition, in the presence of lpr B cells, normal B cells showed little response to an exogenous, T cell-dependent antigen. The data thus indicate that lpr B cells manifest an intrinsic abnormality which is essential for autoantibody production in the lpr model.

scholarly journals Deep Phenotyping of CD11c+ B Cells in Systemic Autoimmunity and Controls

2021 ◽  
Vol 12 ◽  
Author(s):  
Hector Rincon-Arevalo ◽  
Annika Wiedemann ◽  
Ana-Luisa Stefanski ◽  
Marie Lettau ◽  
Franziska Szelinski ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Lupus Erythematosus ◽  
Cell Activation ◽  
B Cell Activation ◽  
Membrane Expression ◽  
Ki 67 ◽  
Inflammatory Conditions ◽  
Systemic Autoimmunity ◽  
Enhanced Expression

Circulating CD11c+ B cells are a key phenomenon in certain types of autoimmunity but have also been described in the context of regular immune responses (i.e., infections, vaccination). Using mass cytometry to profile 46 different markers on individual immune cells, we systematically initially confirmed the presence of increased CD11c+ B cells in the blood of systemic lupus erythematosus (SLE) patients. Notably, significant differences in the expression of CD21, CD27, and CD38 became apparent between CD11c− and CD11c+ B cells. We observed direct correlation of the frequency of CD21−CD27− B cells and CD21−CD38− B cells with CD11c+ B cells, which were most pronounced in SLE compared to primary Sjögren's syndrome patients (pSS) and healthy donors (HD). Thus, CD11c+ B cells resided mainly within memory subsets and were enriched in CD27−IgD−, CD21−CD27−, and CD21−CD38− B cell phenotypes. CD11c+ B cells from all donor groups (SLE, pSS, and HD) showed enhanced CD69, Ki-67, CD45RO, CD45RA, and CD19 expression, whereas the membrane expression of CXCR5 and CD21 were diminished. Notably, SLE CD11c+ B cells showed enhanced expression of the checkpoint molecules CD86, PD1, PDL1, CD137, VISTA, and CTLA-4 compared to HD. The substantial increase of CD11c+ B cells with a CD21− phenotype co-expressing distinct activation and checkpoint markers, points to a quantitative increased alternate (extrafollicular) B cell activation route possibly related to abnormal immune regulation as seen under the striking inflammatory conditions of SLE which shows a characteristic PD-1/PD-L1 upregulation.

Synthesis and anticancer activity of some pyrido[2,3-d]pyrimidine derivatives as apoptosis inducers and cyclin-dependent kinase inhibitors

2019 ◽  
Vol 11 (18) ◽  
pp. 2395-2414 ◽  
Author(s):  
Safinaz E-S Abbas ◽  
Riham F George ◽  
Eman M Samir ◽  
Mostafa MA Aref ◽  
Hatem A Abdel-Aziz
Keyword(s):  
Cell Cycle ◽  
Anticancer Agents ◽  
Kinase Inhibitors ◽  
Cytotoxic Agents ◽  
Cyclin Dependent Kinase ◽  
Apoptosis Induction ◽  
Pyrimidine Derivatives ◽  
Induced Apoptosis ◽  
Emergence Of Resistance ◽  
Mcf 7

Aim: Due to emergence of resistance to available anticancer agents, there is a need to search for new cytotoxic agents. Methods: Pyrido[2,3- d]pyrimidines (4–6) and their tricyclic derivatives (7–13) were prepared and screened for their cytotoxicity against breast MCF-7, prostate PC-3 and lung A-549 cancer cell lines as well as normal fibroblasts WI-38. Results: The most active compounds were 6b, 6e and 8d compared with doxorubicin. Moreover, compounds 6b and 8d induced apoptosis in PC-3 and MCF-7, respectively via activation of CASP3 (in PC-3 only), Bax, p53 and down regulation of Bcl2 in addition to CDK4/6 inhibition. Conclusion: Pyrido[2,3- d]pyrimidine represents an important core for discovery of new potent cytotoxic agents acting on the cell cycle via apoptosis induction through either intrinsic or extrinsic pathways.

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