Analysis of the human anti-pig cellular immune response using the Hu-scid mouse-porcine skin graft model.
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Animals↗
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Results for “SCID mouse”
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Expression of type IV collagenase correlates with the invasion of human lymphoblastoid cell lines and pathogenesis in SCID mice.
An in vitro model, called the Membrane Invasion Culture System (MICS), was used to study the invasive potential of an Epstein-Barr virus (EBV) positive lymphoblastoid cell line (LCL), an EBV-negative Burkitt lymphoma (BL) cell line of American origin and an EBV-positive BL of African origin. MICS measured the ability of these cell lines to invade reconstituted basement membrane-coated filters, which correlated with their tumorigenic and metastatic capabilities in a SCID mouse model. Furthermore, the significantly greater invasive behaviour of the EBV-positive LCL was directly correlated with the cells' ability to express and secrete human type IV collagenase (72 kDa), an important metalloproteinase responsible for the degradation of collagen IV in basement membranes. The data suggest that MICS and the SCID mouse are useful tests of tumorigenicity in lymphoid cells, with measurable effects in both systems related to human type IV collagenase activity. Both models allow further exploration of malignant phenotypes associated with EBV transformation of lymphoid tissues.
Animals↗
Successful reconstitution of human hematopoiesis in the SCID-hu mouse by genetically modified, highly enriched progenitors isolated from fetal liver.
Highly purified CD34++CD38-Lin- hematopoietic progenitors isolated from human fetal liver were infected with the murine retroviral vector, MFG nls-LacZ, which encodes a modified version of the Escherichia coli beta-galactosidase gene. Progenitors that were cocultured with the packaging cell line could reconstitute human bone marrow or thymus implanted in SCID-hu mice. Expression of the beta-galactosidase gene was observed in primitive and committed clonogenic progenitors, mature myeloid, B-lineage cells, and T-lineage cells for up to 4 months after injection into SCID-hu mice. Furthermore, hematopoietic reconstitution by genetically modified progenitor cells could be achieved by the injection of the cells generated from as few as 500 CD34++CD38-Lin- cells, suggesting efficient retroviral gene transfer into fetal liver progenitors.
Animals↗
The ORF47 and ORF66 putative protein kinases of varicella-zoster virus determine tropism for human T cells and skin in the SCID-hu mouse.
The varicella-zoster virus (VZV) genes ORF47 and ORF66 are predicted to encode serine/threonine protein kinases, which are homologs of herpes simplex virus 1 (HSV-1) UL13, and US3. When mutants were constructed by inserting stop codons into ORF47 and ORF66, the recombinants ROka47S and ROka66S, as well as intact ROka replicated in tissue culture. In contrast, inoculation of human thymus/liver or skin implants in SCID-hu mice showed that ORF47 protein was required for viral growth in human T cells and skin. Eliminating ORF66 expression inhibited VZV infectivity for T cells partially but did not impair replication in skin compared with ROka. Infectivity for T cells and skin was restored when ROka47S virus was complemented by insertion of ORF47 into a distant, noncoding site. The ORF47 gene product is the first VZV protein identified as necessary for T cell tropism. It also is essential for skin infectivity in vivo, as is glycoprotein C. Expression of ORF66 did not compensate for the absence of the ORF47 protein. The requirement for ORF47 expression in T cells and skin indicates that this gene product, which is dispensable in vitro, has a critical role within differentiated cells that are essential targets for VZV pathogenesis in vivo.
Animals↗
Structure-based design and engineering of a nontoxic recombinant pokeweed antiviral protein with potent anti-human immunodeficiency virus activity.
A molecular model of pokeweed antiviral protein (PAP)-RNA interactions was used to rationally engineer FLP-102((151)AA(152)) and FLP-105((191)AA(192)) as nontoxic PAPs with potent anti-human immunodeficiency virus (anti-HIV) activities. FLP-102 and FLP-105 have been produced in Escherichia coli and tested both in vitro and in vivo. These proteins depurinate HIV type 1 (HIV-1) RNA much better than rRNA and are more potent anti-HIV agents than native PAP or recombinant wild-type PAP. They are substantially less toxic than native PAP in BALB/c mice and exhibit potent in vivo activities against genotypically and phenotypically nucleoside reverse transcriptase inhibitor-resistant HIV-1 in a surrogate human peripheral blood lymphocyte (Hu-PBL) SCID mouse model of human AIDS. Rationally engineered nontoxic recombinant PAPs such as FLP-102 and FLP-105 may provide the basis for effective salvage therapies for patients harboring highly drug-resistant strains of HIV-1. The documented in vitro potencies of FLP-102 and FLP-105, their in vivo antiretroviral activities in the HIV-infected Hu-PBL SCID mouse model, and their favorable toxicity profiles in BALB/c mice warrant the further development of these promising new biotherapeutic agents.
Aniline Compounds↗
The SCID-hu mouse: a small animal model for the analysis of human hematolymphoid differentiation and function.
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Animals↗
In vivo activation and expansion of T cells by a bi-specific antibody abolishes metastasis formation of human melanoma cells in SCID mice.
Bi-specific antibody fragments (bAB) are used in tumour therapy as a means to redirect and to strengthen effector cell function. It would be of great therapeutic advantage if, in addition, recruitment, expansion and the state of activity of effector cells are influenced by targeting through a bAB. This question was explored in the melanoma-bearing SCID mouse. The chemically coupled Fab' fragments of an anti-CD3 and an anti-p97 monoclonal antibody (MAB) were characterized in vitro for dual binding specificity and support of lymphokine-activated-killer-cell (LAKC) cytotoxicity towards a highly aggressive human melanoma line, which was significantly increased and exceeded levels of antibody-dependent cellular cytotoxicity observed in the presence of the anti-p97 MAB. The in vivo efficacy was tested in the SCID mouse: 5, 10 and 15 days after i.p. application of tumour cells, mice received LAKC (2 x 10(7)) together with bAB (150-100 microg). The application of bAB was repeated at days 20 and 25. Application of LAKC to melanoma-bearing SCID mice prolonged the mean survival time from 22 days of the untreated control group to 41 days. Anti-p97 did not exert any additive effect. In the presence of bAB, melanoma cells did not grow in 3 out of 8 mice. The mean survival time of the 5 mice developing tumours was 45 days. Importantly, none of the mice receiving bAB developed metastases, which were seen in 100% of animals receiving tumour cells or tumour cells plus LAKC or tumour cells plus LAKC plus anti-p97. As revealed by LAKC recovered from the SCID mice, the efficacy of the bAB was based on prolonged persistence of CD8-positive cells as well as on expansion and activation of CD4-positive cells, which was observed only in bAB-treated tumour-bearing mice. The efficiency in recruiting cytotoxic and, in particular, helper T cells suggests bAB as a valuable additive in immunotherapeutic treatment of melanoma patients.
Animals↗
Efficacy of the fully human monoclonal antibody MOR102 (#5) against intercellular adhesion molecule 1 in the psoriasis-severe combined immunodeficient mouse model.
BACKGROUND: Psoriasis is considered as a chronic immune-mediated disease characterized by inflammation and proliferation of the epidermis. OBJECTIVES: Targeting intercellular adhesion molecule 1 (ICAM-1) is an attractive therapeutic option as this molecule is critically involved in leucocyte adhesion and extravasation as well as in lymphocyte activation. METHODS: We have selected the fully human monoclonal antibody MOR102 (#5) against ICAM-1 from the Human Combinatorial Antibody Library (HuCAL). This antibody, as human IgG4 [corrected] was tested for its ability to interfere with lymphocyte activation and adhesion in vitro as well as for its antipsoriatic efficacy in vivo using the psoriasis-severe combined immunodeficient (SCID) mouse model. RESULTS: The antibody demonstrated efficient inhibition of lymphocyte adhesion to ICAM-1 in vitro, with an IC(50) of approximately 0.4 microg mL(-1) (3 nmol L(-1)). In addition, MOR102 (#5) reduced lymphocyte proliferation in mixed lymphocyte cultures by approximately 50%. The in vivo efficacy of MOR102 (#5) was tested on grafts derived from lesional skin of patients with chronic plaque-stage psoriasis transplanted on to SCID mice. Intraperitoneal injection of 10 mg kg(-1) of MOR102 (#5) antibody every alternate day over a period of 4 weeks resulted in reconstitution of orthokeratotic differentiation and a significant (P < 0.05) reduction in epidermal thickness as well as marked reduction in the inflammatory infiltrate. Therapeutic activity may be related to the targeting of ICAM-1 on keratinocytes and thus preventing efficient activation of local T cells. CONCLUSIONS: Based on the efficacy of the fully human monoclonal antibody MOR102 (#5) shown in vitro as well as in vivo in the psoriasis-SCID mouse model, initiation of clinical studies is indicated.
Animals↗
Antisense oligonucleotides suppress B-cell lymphoma growth in a SCID-hu mouse model.
The t(14;18) translocation is found in the majority follicular lymphomas and some high grade B-cell lymphomas. This is results in deregulation of the BCL-2 gene and appears to play a role in oncogenesis. Various numbers of cells from a cell line derived spontaneously from a patient with B-cell lymphoma bearing the t(14;18) translocation and negative for the Epstein-Barr virus (EBV) were injected by IP, IV, and SC routes into SCID mice. The mice developed lymphoma bearing the t(14;18) translocation with as few as 5 x 10(6) cells within 28 days. This was determined by histological examination. The higher the cell inoculation the more rapidly the lymphoma developed. Engraftment of the tumour cells was determined by PCR for the t(14;18) breakpoint region on peripheral blood samples and could be detected prior to development of overt lymphoma. Having established a lymphoma model the cells were treated with antisense oligonucleotides to the first open reading frame of the BCL-2 gene prior to inoculation of the SCID mice. Control treatments with sense and nonsense oligonucleotides was also performed. At 28 days the sense, nonsense and untreated cell SCID mice had developed lymphoma, however, the antisense treated group failed to develop lymphoma. The findings demonstrate the modelling of B-cell lymphoma bearing the t(14;18) translocation and the ability to modify the lymphoma process with the use of antisense oligonucleotides to the BCL-2 gene. Reduction of the BCL2 protein suppresses the oncogenic potential of these lymphoma cells confirming that it plays an essential role in the development of malignancy.
Animals↗
TXU (anti-CD7)-pokeweed antiviral protein as a potent inhibitor of human immunodeficiency virus.
We have evaluated the clinical potential of TXU (anti-CD7)-pokeweed antiviral protein (PAP) immunoconjugate (TXU-PAP) as a new biotherapeutic anti-human immunodeficiency virus (anti-HIV) agent by evaluating its anti-HIV type 1 (anti-HIV-1) activity in vitro, as well as in a surrogate human peripheral blood lymphocyte-severe combined immunodeficient (Hu-PBL-SCID) mouse model of human AIDS. The present report documents in a side-by-side comparison the superior in vitro anti-HIV-1 activity of TXU-PAP compared to the activities of zidovudine, 2',3'-didehydro-2',3'-dideoxythymidine, unconjugated PAP, and B53-PAP, an anti-CD4-PAP immunoconjugate. Notably, TXU-PAP elicited potent anti-HIV activity in the Hu-PBL-SCID mouse model of human AIDS without any side effects and at doses that were very well tolerated by cynomolgus monkeys. Furthermore, plasma samples from TXU-PAP-treated cynomolgus monkeys showed potent anti-HIV-1 activity in vitro.
Acquired Immunodeficiency Syndrome↗
Retroviral gene transfer of an antisense construct against membrane type 1 matrix metalloproteinase reduces the invasiveness of rheumatoid arthritis synovial fibroblasts.
OBJECTIVE: Membrane type 1 matrix metalloproteinase (MT1-MMP) is expressed prominently in rheumatoid arthritis synovial fibroblasts (RASFs), but the specific contribution of MT1-MMP to fibroblast-mediated destruction of articular cartilage is incompletely understood. This study used gene transfer of an antisense expression construct to assess the effects of MT1-MMP inhibition on the invasiveness of RASFs. METHODS: Retroviral gene transfer of a pLXIN vector-based antisense RNA expression construct (MT1-MMPalphaS) to MT1-MMP was used to stably transduce RASFs. Levels of MT1-MMP RNA and protein were determined by quantitative polymerase chain reaction, Western blotting, and immunocytochemistry in MT1-MMPalphaS-transduced RASFs as well as in control cells, with monitoring for 60 days. The effects of MT1-MMPalphaS on the invasiveness of RASFs were analyzed in the SCID mouse co-implantation model of RA. RESULTS: MT1-MMPalphaS-transduced RASFs produced high levels of antisense RNA that exceeded endogenous levels of MT1-MMP messenger RNA by 15-fold and resulted in a down-regulation of MT1-MMP at the protein level. Inhibition of MT1-MMP production was maintained for 60 days and significantly reduced the invasiveness of RASFs in the SCID mouse model. Whereas prominent invasion into cartilage by non-transduced and mock-transduced RASFs was observed (mean invasion scores 3.0 and 3.1, respectively), MT1-MMPalphaS-transduced cells showed only moderate invasiveness (mean invasion score 1.8; P < 0.05). CONCLUSION: The data demonstrate that an antisense RNA expression construct against MT1-MMP can be generated and expressed in RASFs for at least 60 days. Inhibition of MT1-MMP significantly reduces the cartilage degradation by RASFs.
Animals↗
Analysis of lectin binding properties on human Burkitt's lymphoma cell lines that show high spontaneous metastasis to distant organs in SCID mice: the binding sites for soybean agglutinin lectin masked by sialylation are closely associated with metastatic lymphoma cells.
Alterations in cell surface carbohydrates on human lymphoma cell lines with different spontaneous metastatic potential in the severe combined immunodeficiency (SCID) mouse model were analyzed. A difference in cell surface carbohydrates between high- (HBL-2, HBL-7 and HBL-8) and no- or low-(HBL-4, HBL-6, Daudi and Raji) spontaneous metastatic human lymphoma cell lines were analyzed on a FACScan using fluorescein-isothiocyanate (FITC)-conjugated lectins. The most consistent difference in lectin binding properties was found with soybean agglutinin (SBA) lectin. High-metastatic lymphoma cells (HBL-7 and HBL-8 cells) in vitro were found to bind the SBA lectin, but the cells in vivo (in primary tumors and metastatic tumors of SCID mice) showed considerably reduced SBA lectin binding. In addition, HBL-2 cells that almost did not bind SBA lectin in vitro and in vivo showed high spontaneous metastasis. Neuraminidase treatment revealed that SBA lectin binding sites were masked by sialic acid. On the other hand, no- or low-metastatic lymphoma cells in vitro and in vivo were found to bind SBA lectin. HBL-8 cell clones without SBA lectin binding showed high spontaneous metastasis to distant organs in SCID mice but HBL-8 cell clones with SBA lectin binding showed very low spontaneous metastasis. Sophora Japonica agglutinin (SJA) lectin is able to recognize the carbohydrates in common with SBA lectin, but it does not appear to be associated with metastatic capacity. These results suggest that the sialylation of particular carbohydrate residues on human lymphoma cells that are recognized by SBA lectin may be associated with the spontaneously metastatic capacity of human lymphoma cell lines in our SCID mouse model.
Animals↗
Novel delivery system enhances efficacy of antiretroviral therapy in animal model for HIV-1 encephalitis.
Most potent antiretroviral drugs (e.g., HIV-1 protease inhibitors) poorly penetrate the blood-brain barrier. Brain distribution can be limited by the efflux transporter, P-glycoprotein (P-gp). The ability of a novel drug delivery system (block co-polymer P85) that inhibits P-gp, to increase the efficacy of antiretroviral drugs in brain was examined using a severe combined immunodeficiency (SCID) mouse model of HIV-1 encephalitis (HIVE). Severe combined immunodeficiency mice inoculated with HIV-1 infected human monocyte-derived macrophages (MDM) into the basal ganglia were treated with P85, antiretroviral therapy (ART) (zidovudine, lamivudine and nelfinavir (NEL)), or P85 and ART. Mice were killed on days 7 and 14, and brains were evaluated for levels of viral infection. Antiviral effects of NEL, P85, or their combination were evaluated in vitro using HIV-1 infected MDM and showed antiretroviral effects of P85 alone. In SCID mice injected with virus-infected MDM, the combination of ART-P85 and ART alone showed a significant decrease of HIV-1 p24 expressing MDM (25% and 33% of controls, respectively) at day 7 while P85 alone group was not different from control. At day 14, all treatment groups showed a significant decrease in percentage of HIV-1 infected MDM as compared with control. P85 alone and combined ART-P85 groups showed the most significant reduction in percentage of HIV-1 p24 expressing MDM (8% to 22% of control) that were superior to the ART alone group (38% of control). Our findings indicate major antiretroviral effects of P85 and enhanced in vivo efficacy of antiretroviral drugs when combined with P85 in a SCID mouse model of HIVE.
AIDS Dementia Complex↗
[Protection of mdr1 transfected cord blood mononuclear cell graft against anticancer agents in vivo].
OBJECTIVE: To explore the myelo-protection effect of mdr1 transfected cord blood cells (CBMNCs) graft against high-dose homoharringtonine leukemia-bearing severe combined immunodeficient (SCID) mice model. METHODS: Multidrug resistant (mdr1)gene was transferred into CBMNCs by a retrovirus vector, containing full-length cDNA of human mdr1 gene. CBMNCs and high-titer retrovirus supernatant were cocultured with cytokine combinations for 5 - 6 days. The SCID mouse models bearing human HL-60 cell leukemia were divided into three groups. Group A received tail vein injection of 2 x 10(6) mdr1 gene transduced CBMNCs at day 1 and 3, groups B and C 2 x 10(6) un-transduced CBMNCs and same volume of normal saline, respectively. The 3 groups of the mouse model were treated with weekly escalated doses of homoharringtonine. The peripheral white blood cell (WBC) counts, the human leukemia cells percentage in peripheral blood, the histological findings of main organs were assayed. The CD33 positive HL-60 cells in bone marrow were determined by flow cytometry. The function and expression of mdr1 gene were examined by PCR, immunochemistry (IC) and DNR extrusion test in vivo. RESULTS: (1) mdr1 gene was transferred into CBMNCs successfully and the transfection frequency was 30%. (2) Leukemia SCID mice were xenotransplanted with mdr1-transfected BMMNCs by a programmed procedure and could be used as a valuable model for in vivo evaluating myelo-protection effects. (3) The transfected mice could tolerate homoharringtonine 5 approximately 6 folds higher than conventional dose and kept peripheral WBC count at a mean of 3 x 10(9)/L, with the peripheral human myeloid leukemia cells percentage decreasing to less than 5%. Histological examination showed that there was no leukemia infiltration in the main organs, the CD33 positive HL-60 cells in bone marrow were less than 5%. (4) The repopulation frequency of the transfected CBMNs in marrow were 9.13%. DNR extrusion test confirmed that the P-gp product maintained its biological function in the marrow. CONCLUSION: mdr1 transferred-human CBMNC can xenotransplanted and repopulated in leukemia-bearing SCID mouse and are protected from chemotherapy-induced myelosuppression.
ATP Binding Cassette Transporter, Subfamily B, Mem↗
Ribozymes that inhibit the production of matrix metalloproteinase 1 reduce the invasiveness of rheumatoid arthritis synovial fibroblasts.
OBJECTIVE: To investigate whether retroviral gene transfer of ribozymes targeting matrix metalloproteinase 1 (MMP-1) inhibits the production of MMP-1 in rheumatoid arthritis synovial fibroblasts (RASFs) and reduces the invasiveness of these cells in vivo. METHODS: MMP-1-specific ribozymes (RzMMP-1) were designed and cloned into the pLNSX retroviral vector. Cleavage of MMP-1 was determined in vitro, and the most effective ribozyme was selected for further investigation. RASFs were transduced with replication-deficient viruses carrying RzMMP-1 or with empty viruses (mock). Quantitative polymerase chain reaction with cleavage site-spanning fluorescent probes was used to measure the levels of MMP-1, MMP-9, and MMP-13 messenger RNA. In addition, protein levels of MMP-1 in cell culture supernatants were determined by enzyme linked immunosorbent assay. The effects of stimulation with lipopolysaccharide (LPS) and tumor necrosis factor alpha (TNFalpha) on the production of MMP-1 were assessed accordingly. The invasiveness of RzMMP-1-transduced, mock-transduced, and untransduced RASFs was analyzed in the SCID mouse in vivo model of RA. RESULTS: Transduction of RASFs with RzMMP-1 significantly decreased the production of MMP-1 in RASFs without affecting other MMPs, such as MMP-9 and MMP-13. RzMMP-1 not only reduced the spontaneous production of MMP-1, but also prevented the LPS- and TNFalpha-induced increase in MMP-1 production. Inhibition of MMP-1 was maintained for at least 2 months and was accompanied by a significant reduction of the invasiveness of RASFs in the SCID mouse model of RA. CONCLUSION: Intracellular expression of ribozymes constitutes a feasible tool for inhibiting the production of matrix-degrading enzymes. Inhibition of MMP-1 alone results in a significant reduction of cartilage invasion by RASFs.
Animals↗
Childhood acute myeloid leukemia in mice with severe combined immunodeficiency.
Primary bone marrow blasts from 4 children with t(8;21) acute myeloid leukemia (AML), 6 children with inv(16) AML, and 2 children with t(9;11) AML were injected intravenously or transplanted under the kidney capsule of sublethally irradiated mice with severe combined immunodeficiency (SCID). Leukemic cells from all AML patients infiltrated the SCID mouse thymus, suggesting that the thymic microenvironment supports the survival and growth of human AML blasts. Blasts from 1 of 4 t(8;21) AML patients and 4 of 6 inv(16) AML patients caused histopathologically detectable disseminated leukemia. Blasts from the remaining patients produced disseminated occult leukemia that was only detected by polymerase chain reaction. Occurrence of histopathologically detectable disseminated leukemia was dependent on intravenous injection of leukemic cells; none of the mice challenged with an inoculum transplanted under the kidney capsule developed overt leukemia. No obvious association was noted between occurrence of leukemia in SCID mice and clinical or laboratory features presented by patients, including age, sex, or leukocyte count at diagnosis. To our knowledge, this study is the first to show that leukemic blasts from children with newly diagnosed AML, especially inv(16) AML, can cause disseminated human leukemia in SCID mice without exogenous cytokine support. The SCID mouse model system may prove particularly useful for designing more effective treatment strategies against childhood AML.
Adolescent↗
A mutated superantigen SEA D227A fusion diabody specific to MUC1 and CD3 in targeted cancer immunotherapy for bile duct carcinoma.
In cancer immunotherapy research, many bispecific antibodies (BsAbs) have been developed for directing T cells toward tumor cells. Recent advances in genetic engineering have made it possible to prepare immunoglobulin fragments consisting of variable domains using bacterial expression systems. Therefore, recombinant BsAbs, termed diabodies, have attracted particular attention. We have previously produced an anti-MUC1 x anti-CD3 diabody (Mx3 diabody) in an Escherichia coli ( E. coli) expression system. In order to reinforce the antitumor effects of the Mx3 diabody, mutated superantigen staphylococcal enterotoxin A (SEA) D227A was genetically fused to the Mx3 diabody. The SEA D227A fusion Mx3 diabody (SEA D227A-Mx3 diabody) thus constructed showed remarkable MUC1-specific antitumor effects when used with effector cells (lymphokine-activated killer cells with T-cell phenotype [T-LAK] and peripheral blood mononuclear cells [PBMCs]). In the bile duct carcinoma (BDC)-xenografted severe combined immunodeficient (SCID) mouse model, it also demonstrated strong antitumor activity when administered i.v. together with T-LAK cells and interleukin-2 (IL-2). In this experiment, the complete disappearance of tumors was observed in 3 out of 6 mice, and the other 3 showed marked retardation of tumor growth. Therefore, the SEA D227A-Mx3 diabody is considered to be a promising reagent in specific targeted immunotherapy for BDC and other MUC1-positive carcinomas. This is the first report on a diabody that is effective in treating human solid cancers in the xenografted SCID mouse experimental model.
Animals↗
Expression of sentrin, a novel antiapoptotic molecule, at sites of synovial invasion in rheumatoid arthritis.
OBJECTIVE: Sentrin, a novel antiapoptotic molecule, has been shown to interact with the signal-competent form of Fas/APO-1 and tumor necrosis factor receptor I (TNFRI), and thereby, to protect cells against anti-Fas/APO-1- and TNF-induced cell death. Since reduced apoptosis in the synovial lining is supposed to contribute to synovial hyperplasia in rheumatoid arthritis (RA), we searched for the expression of sentrin-1 messenger RNA (mRNA) in synovium from patients with RA. METHODS: The expression of sentrin-1 mRNA was examined by in situ hybridization on snap-frozen sections of normal and RA synovial tissues as well as on paraffin-embedded RA synovial specimens, including the interface of cartilage-bone and invading synovium. Immunohistochemical double labeling after in situ hybridization was performed to further characterize sentrin-1 mRNA-expressing cells. In addition, quantitative analysis of sentrin-1 mRNA expression in RA synovial fibroblasts (RASF), osteoarthritis synovial fibroblasts (OASF), and normal fibroblasts was performed by quantitative real-time polymerase chain reaction. Expression levels were standardized to the expression of GAPDH. The in vivo maintenance of sentrin expression in RASF aggressively invading human cartilage was explored in the SCID mouse model of RA. RESULTS: A marked expression of sentrin-1 mRNA could be seen in all RA synovial specimens, predominantly in SF of the lining layer and at sites of invasion of RA synovium into cartilage. In normal synovial tissues, no sentrin-1 mRNA was detectable. RASF showed a maximum 32.5-fold (mean +/- SD 14.9 +/- 11.6) increase of sentrin-1 mRNA expression compared with normal fibroblasts and a maximum 31.4-fold (mean +/-SD 14.3 +/- 10.9) increase compared with OASF. When coimplanted with normal human cartilage in the SCID mouse model, invading RASF maintained their sentrin-1 mRNA expression for at least 60 days in vivo. CONCLUSION: The marked expression of sentrin in rheumatoid synovial tissue, but not in normal or OA synovial tissue, may contribute to the modulation of Fas- and TNFR-mediated apoptosis in RA synovium, and thereby extend the lifespan of invasive, cartilage-destructive SF.
Animals↗