Biomedical subjects

T Mohanakumar

Publications and source records attributed to T Mohanakumar.

At least 55 records · Page 3Linked to original sources

PubMed2003

Anti-HLA class I antibody binding to airway epithelial cells induces production of fibrogenic growth factors and apoptotic cell death: a possible mechanism for bronchiolitis obliterans syndrome.

Development of anti-HLA class I antibodies is associated with bronchiolitis obliterans syndrome (BOS) after lung transplantation. BOS is characterized histologically by significant fibrosis and airway epithelial cell (AEC) apoptosis. Thus, this study was designed to determine whether anti-HLA class I antibodies can activate AECs to produce growth factors and to undergo apoptosis. KCC-266 AECs were activated with the W6/32 anti-HLA class I monoclonal antibody. Proliferation and apoptosis levels were determined after 24, 48, and 72 hours. The induction of fibroblast and bronchial smooth muscle cell proliferation by anti-HLA class I activated AECs was assessed in the presence of neutralizing antibodies against various growth factors. The anti-HLA class I induced AEC proliferation after 24 hours followed by significant induction of apoptosis after 48 hours. Anti-HLA class I activated AECs produced soluble growth factors that stimulated fibroblasts but not bronchial smooth muscle cells. The stimulation of fibroblast proliferation was inhibited by antibodies against platelet-derived growth factor, heparin-binding epidermal growth factor, insulin-like growth factor 1, and basic fibroblast growth factor. The results from this study suggest that anti-HLA class I alloantibodies may play an important role in the pathogenesis of BOS by inducing proliferation, growth factor production, and apoptotic cell death in AECs.

Antibodies, Monoclonal↗

PubMed2003

Concomitant augmentation of type 1 CD4+ and CD8+ T-cell responses during successful interferon-alpha and ribavirin treatment for chronic hepatitis C virus infection.

The combined interferon-alpha (IFN-alpha) and ribavirin (IFN-alpha/ribavirin) therapy for chronic hepatitis C virus (HCV) infection results in sustained viral eradication in 31%-64% of the patients. Previous studies have strongly suggested that HCV-specific T-cell responses maybe modulated during this therapy. The objective of this study was to further define the effect of IFN-alpha/ribavirin therapy on type 1 and type 2 HCV-specific CD4(+) and CD8(+) T-cell responses during IFN-alpha/ribavirin therapy. Toward this, serial CD8(+) T-cell responses to HCV-derived epitopes and CD4(+) T-cell responses to the HCV core antigen were analyzed in four patients before (baseline), during (at 24 weeks), and at the end (at 48 weeks) of IFN-alpha/ribavirin therapy. Therapy-induced viral clearance in three patients was associated with a significant augmentation of HCV-specific type 1 CD4(+) and CD8(+) T-cell responses. In contrast, in a patient who did not respond to therapy, a significant HCV-specific CD4(+) Th2 cell reactivity was observed accompanied by a lack of augmentation of the HCV-specific CD8(+) T-cell reactivity. These results indicate that enhancement of HCV-specific CD4(+) and CD8(+) T-cell responses is an important factor in determining the response to the IFN-alpha/ribavirin therapy and the outcome of the HCV infection.

Antiviral Agents↗

PubMed2003

Xenoreactive anti-Galalpha(1,3)Gal antibodies prevent porcine endogenous retrovirus infection of human in vivo.

The discovery of porcine endogenous retroviruses (PERV) has raised concerns regarding the safety of pig to human xenotransplantation. In this study, we examined PERV infection of human cells in vivo. Furthermore, we examined the effect of human xenoreactive natural antibody on in vivo PERV infection. Human peripheral blood leukocyte reconstituted severe combined immunodeficiency mice were transplanted with porcine aortic endothelial cells (PAEC). PERV gene expression was readily detected in human leukocytes after transplantation. In contrast, human leukocytes harvested from mice treated with human serum or anti-Galalpha(1,3)Gal antibody prevented PERV infection in 6 of 8 mice. These results provide the first evidence that PERV can infect human cells in vivo and that natural xenoreactive antibody can prevent this infection.

Animals↗

PubMed2003

Association of the HLA-DR15/HLA-DQ6 haplotype with development of choroidal neovascular lesions in presumed ocular histoplasmosis syndrome.

Associations of human leukocyte antigen DR2 (HLA-DR2) and HLA-B7 with presumed ocular histoplasmosis syndrome (POHS) in the United States has been previously described. However, these associations were determined by means of low-resolution, complement-dependent cytotoxicity assays for HLA-A, HLA-B, and HLA-DR molecules. To determine whether POHS is associated with other HLA alleles within the HLA-A, HLA-B, HLA-DR, and HLA-DQ loci, we performed a case control study of 34 patients diagnosed with macular choroidal neovascular membrane secondary to POHS and 45 healthy control individuals. Peripheral blood-derived DNA from the study patients was typed for HLA genes by means of sequence-specific primers that gave low-medium allele resolution. Significant associations were observed between HLA-B7 (X2 = 14.30, pc = 0.004, relative risk = 8.23), HLA-DR15 (X2 = 29.08, pc = 0.000001, relative risk = 27.50), and HLA-DQ6 (X2 = 23.09, pc = 0.00001, relative risk = 27.43) and POHS. Because there are strong linkage disequilibria between HLA-DR15 (a subtype of HLA-DR2) and HLA-B7 as well as HLA-DQ6, the significantly higher association of HLA-DR15 and HLA-DQ6 with POHS as compared to HLA-B7 suggests that the former alleles mediate susceptibility to the disease. In conclusion, there is a significant association between the HLA-DR15/HLA-DQ6 haplotype and development of choroidal neovascular lesions in POHS.

Choroid↗

PubMed2003

Concomitant allorecognition of mismatched donor HLA class I- and class II-derived peptides in pediatric lung transplant recipients with bronchiolitis obliterans syndrome.

BACKGROUND: The authors' previous studies with 2 different adult patient populations demonstrated a correlation between indirect allorecognition of mismatched donor HLA Class I- and Class II-derived peptides and the development of bronchiolitis obliterans syndrome (BOS) after lung transplantation. The aim of this study was to determine whether a parallel allorecognition of mismatched donor HLA Class I- and Class II-derived peptides occurs after lung transplantation and to determine its correlation with the development of BOS after lung transplantation in a group of pediatric patients. METHODS: Peripheral blood mononuclear cells from 7 BOS-positive and 6 BOS-negative pediatric lung transplant recipients (age, 11.5 +/- 4.4 years) were cultured in the presence of synthetic peptides corresponding to the alpha-chain hypervariable regions of a mismatched donor HLA Class I molecule and the beta-chain hypervariable region of a mismatched donor HLA-DR molecule. The frequencies of HLA Class I and Class II alloreactive T cells were determined using limiting dilution analysis. RESULTS: A significant increase (p = 0.025) in HLA Class I-alloreactive T cells was observed in BOS-positive patients (7.1 x 10(-5) +/- 4.3 x 10(-5)) compared with BOS-negative patients (2.1 x 10(-5) +/- 1.8 x 10(-6)). In addition, a significant increase (p = 0.033) in HLA Class II-alloreactive T cells also was observed in BOS-positive patients (9.6 x 10(-5) +/- 7.9 x 10(-5)) compared with BOS-negative patients (1.3 x 10(-5) +/- 2.1 x 10(-6)). CONCLUSIONS: This study indicates that a parallel CD4+ T-cell alloreactivity to both donor HLA Class I and Class II molecules may play a role in the pathogenesis of BOS both in adult and pediatric lung transplant recipients.

Bronchiolitis Obliterans↗

PubMed2003

Generation of CD8+ cytotoxic T lymphocytes against breast cancer cells by stimulation with mammaglobin-A-pulsed dendritic cells.

Mammaglobin-A is exclusively expressed by breast cancer cells. Thus, mammaglobin-A-specific T cell immune responses may be useful for the design of new breast cancer-specific immunotherapies. We show herein that CD8+ T cells generated against recombinant mammaglobin-A-pulsed dendritic cells display a marked cytotoxic activity against mammaglobin-A-positive breast cancer cell lines. This study indicates the immunotherapeutic potential of this novel antigen for the treatment of breast cancer.

Antibody Specificity↗

PubMed2002

Interleukin-6 and interferon-gamma gene polymorphisms in the development of bronchiolitis obliterans syndrome after lung transplantation.

BACKGROUND: A number of genetic polymorphisms have been shown to regulate the production and secretion of tumor necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta1, interferon (IFN)-gamma, interleukin (IL)-6, and IL-10. Several of these genetic polymorphisms have been shown to be associated with either acute or chronic rejection of kidney, liver, and heart allografts and with development of allograft fibrosis after lung transplantation. The aim of this study was to assess the effect of these genetic polymorphisms on the development of bronchiolitis obliterans syndrome (BOS) after lung transplantation. METHODS: Genetic polymorphisms were detected by means of polymerase chain reaction in 93 lung allograft recipients for functional polymorphisms in the TNF-alpha (-308), TGF-beta1 (+869 and +915), IL-6 (-174), IFN-gamma (+874), and IL-10 (-1082, -819, and -592) genes. Then, a correlation between BOS development and the presence of these cytokine genotypes was determined using Kaplan-Meier actuarial analysis. RESULTS: A significant correlation was detected between the presence of high-expression polymorphisms of the IL-6 and IFN-gamma genes and BOS development after lung transplantation (P =0.045 and 0.039, respectively). Also, patients with high-expression polymorphisms in both genes developed BOS significantly earlier than patients with low-expression polymorphisms in one or both genes, suggesting a synergistic effect of the alleles during BOS pathogenesis (P =0.016). No correlation was detected between polymorphisms of the TNF-alpha, TGF-beta1, and IL-10 genes and development of BOS after lung transplantation. CONCLUSIONS: The presence of high-expression polymorphisms at position -174 of the IL-6 gene and position +874 of the IFN-gamma gene significantly increases the risk for BOS development after lung transplantation.

Bronchiolitis Obliterans↗

PubMed2002

Different kinetics of obliterative airway disease development in heterotopic murine tracheal allografts induced by CD4+ and CD8+ T cells.

BACKGROUND: Both T and B cells have been shown to be implicated in the pathogenesis of bronchiolitis obliterans syndrome, which is considered to represent chronic lung allograft rejection. However, the relative contributions of T cells and alloantibodies in the pathogenesis of the disease are still unknown. In this study, we used an heterotopic murine tracheal transplantation model to determine the contribution of these components of the immune system in the pathogenesis of posttransplant obliterative airway disease (OAD). METHODS: Tracheal allografts from BALB/c and HLA-A2-transgenic (HLA-A2+) mice were heterotopically transplanted into C57BL/6, CD4-knockout (KO), CD8-KO, Ig-KO, and Rag1-KO mice. In additional experiments, recipient mice were pretreated with depleting antibodies against CD4+, CD8+, and NK1.1+ cells. Development of OAD was determined by histopathology at days 10, 30, 60, 90, and 180 after transplantation. RESULTS: HLA-A2+ allografts transplanted into C57BL/6, CD8-KO, and Ig-KO mice demonstrated OAD lesions by day 30. In contrast, allografts transplanted into CD4-KO mice showed no OAD lesions at day 30, partial OAD development by days 60 and 90, and complete OAD development by day 180. No OAD development was observed in allografts transplanted into Rag1-KO mice. Treatment with anti-NK1.1 antibody did not show any effect on posttransplant OAD development. In contrast, anti-CD4+ or anti-CD8+ antibody treatments partially reduced the OAD histopathology and combined anti-CD4/CD8 antibody treatment further abrogated the histopathology of the disease. CONCLUSION: These results show that both CD4+ and CD8+ T cells have a role in the pathogenesis of OAD and that natural killer cells and alloantibodies are not necessary for the development of this disease.

Animals↗

PubMed2002

Differentiation and functional maturation of human CD14(+) adherent peripheral blood monocytes by xenogeneic endothelial cells: up-regulation of costimulation, cytokine generation, and toll-like receptors.

BACKGROUND: Dendritic cells (DCs) can be generated from peripheral blood mononuclear cells (PBMC) after stimulation with exogenous granulocyte-macrophage colony stimulating factor and interleukin (IL)-4. Further, extravasation of monocytes through human endothelial cells can also cause differentiation, maturation, and expression of DC-specific phenotype. However, it is unclear whether human DCs can be generated from monocytes under the influence of xenogeneic endothelial cells in the absence of exogenous cytokines. We therefore analyzed and compared the effect of human and porcine endothelial cells on the differentiation of human monocytes into DC. METHODS: Adherent peripheral blood CD14(+) monocytes were cultured in the presence of different cytokine combinations, human or porcine endothelial cells, and smooth muscle cells, and analyzed for DC-specific antigen expression, antigen-presenting capacity, cytokine and chemokine generation, and expression of Toll-like receptors by flow cytometry and reverse transcription polymerase chain reaction. RESULTS: Human monocytes express a DC-specific surface phenotype and efficiently present allo- and xenoantigens to allogeneic T cells after co-culturing with allogeneic and xenogeneic endothelial cells, respectively. Differentiation of monocytes under different stimulating conditions is also accompanied by the up-regulation of costimulatory molecules (CD40, CD80, CD86), adhesion molecules (CD54), human leukocyte antigen (HLA)-DR, synthesis of cytokines tumor necrosis factor-alpha, IL-12p70, IL-10, and differential expression of message for Toll-like receptors. CONCLUSIONS: Porcine aortic endothelial cells can provide immunostimulatory signals to human peripheral blood adherent monocytes similar to allogeneic endothelial cells through the participation of innate immune mechanisms.

Antigens, CD↗

PubMed2002

Indirect recognition and antibody production against a single mismatched HLA-A2-transgenic molecule precede the development of obliterative airway disease in murine heterotopic tracheal allografts.

BACKGROUND: Previous studies have implicated the allogeneic immune response in the development of obliterative bronchiolitis after lung transplantation. However, the progression of specific pathogenic events leading to this form of chronic allograft dysfunction have not been well characterized. We used a murine tracheal transplantation model in which a single mismatched HLA-A2-transgenic molecule is indirectly recognized by the recipient CD4(+) T cells to show that obliterative airway disease (OAD) that developed in these allografts was preceded by indirect recognition of the HLA-A2 molecule and subsequent development of anti-HLA-A2 antibodies. METHODS: Tracheas from HLA-A2(+) C57BL/6 mice were heterotopically transplanted into C57BL/6 mice. Allograft histopathology as well as anti-HLA-A2 T-cell proliferative responses and anti-HLA-A2 antibody development were determined at days 5, 10, 20, and 28 after transplantation. RESULTS: All of the HLA-A2(+) tracheal allografts transplanted into C57BL/6 recipients demonstrated complete development of OAD by day 20. Spleen cells from the mice that underwent transplantation demonstrated significant proliferation against HLA-A2(+) cells by day 5. Indirect recognition of HLA-A2-derived peptides by spleen cells from allograft recipients was also higher on days 5 and 10 as compared with irrelevant peptides derived from HLA-A1, HLA-A3, and HLA-B44. Allograft recipients showed detectable levels of anti-HLA-A2 antibodies by day 5 and full development of anti-HLA-A2 antibodies by day 20. CONCLUSION: These results show that sensitization of CD4+ T cells against the mismatched HLA-A2 alloantigen precedes the development of anti-HLA antibodies as well as OAD, suggesting an important role for alloreactive CD4(+) T-cell activation and alloantibody development in the immunopathogenesis of OAD.

Animals↗

PubMed2002

In vitro T cell proliferation from kidney allograft biopsies with unremarkable pathology: new strategies for an old problem.

Acute rejection of renal allografts is mediated by infiltrating alloreactive T cells. The goals of this study were to correlate T cell proliferation with rejection and to determine whether T cell proliferation in the absence of rejection would predict future rejection episodes. Toward this, kidney biopsies (n=100) were cultured in the presence of interleukin-2. Cultures were examined at 4, 24, and 48 hr for T cell proliferation. A strong correlation was observed between T cell proliferation at any time point and rejection. There was not a significant correlation between T cell proliferation in biopsies with no rejection and the occurrence of a rejection episode within 2 months. However, T cell proliferation after 4 hr was a better predictor of the occurrence of rejection within 2 months compared with observations after 24 and 48 hr. Therefore, a subgroup of patients with unremarkable biopsies but T cell proliferation may be at risk for rejection and warrant closer observation and possible tailoring of immunosuppression.

Adult↗

PubMed2002

Rejection of porcine islet xenografts mediated by CD4+ T cells activated through the indirect antigen recognition pathway.

We have previously demonstrated that human T cells responding to porcine islets are primarily CD4+ and recognized porcine major histocompatibility complex class I molecules through the indirect pathway of antigen presentation. To determine whether this mechanism is responsible for rejection of adult porcine islets xenografts, porcine islets from adult pigs were transplanted under the kidney capsule of streptozotocin-treated CD4-knockout (KO), CD8-KO, Ig-KO and normal C57BL/6 mice. Islet xenografts were acutely rejected with similar kinetics when transplanted into normal C57BL/6 (MST=17.6 +/- 3.5 days) and Ig-KO (MST=19.0 +/- 1.7 days) mice. Interestingly, islet xenografts were rejected significantly earlier when transplanted into CD8-KO mice as compared with normal C57BL/6 (MST=7.0 +/- 0.01 days, P=2 x 10-4). Histopathological analysis revealed classical acute cellular rejection with severe diffuse interstitial cellular infiltrates in all rejected islet xenografts. In contrast, islet xenografts were not rejected when transplanted into CD4-KO mice (MST >/= 100 days, P=1 x 10-9). Histopathological analysis revealed no cellular infiltrates and intact islet xenografts. CD4+ T cells from both normal C57BL/6 and CD8-KO xenograft recipients showed detectable proliferative responses to porcine islets in the presence but not in the absence of syngeneic antigen-presenting cells. In addition, the anti-islet proliferative responses observed in normal C57BL/6 mice were significantly lower than those observed in CD8-KO mice. IgG anti-porcine antibodies were readily detected in C57BL/6 and CD8-KO xenograft recipients but not in Ig-KO or CD4-KO recipients. These results indicate that indirectly activated CD4+ T cells mediate acute rejection of adult porcine islet xenografts and that xenoreactive CD8+ T cells and antibodies are not necessary in this process.

Animals↗

PubMed2002

Activation of natural killer cells and macrophages by porcine endothelial cells augments specific T-cell xenoresponse.

The rejection of xenografts is characterized by infiltration of monocytes and natural killer (NK) cells into the graft, suggesting an important role for the innate immune system in xenorecognition. In this study, purified human NK or T cells were cocultured with porcine endothelial cells, and cytokines were analyzed by ELISA and intracellular FACS. We demonstrated a vigorous human anti-porcine xenoresponse that was associated with a strong T-cell proliferation against porcine endothelial cells. Limiting dilution cloning and T-cell receptor (TCR) Vbeta gene usage revealed a low number of xenoreactive T-cell precursors. We demonstrated that xenogeneic porcine but not allogeneic human endothelial cells induced the early production of interferon (IFN)-gamma by human NK cells but not by CD3+ T cells. Porcine xenoantigen-induced IFN-gamma production was only partially dependent on IL-12. Blocking IL-12 with neutralizing antibodies or by depletion of human macrophages partially decreased IFN-gamma production by CD56+ NK cells. Three-color flow cytometry revealed that IL-12 was produced through a species-specific activation of human macrophages by porcine endothelial cells. Our results indicate that the direct activation of NK cells and macrophages by porcine endothelial cells provides a unique pathway of xenorecognition that augments downstream specific T-cell immunity and represents a powerful effector mechanism in xenograft rejection.

Animals↗

PubMed2002

Antibodies to 70 kD and 90 kD heat shock proteins are associated with graft-versus-host disease in peripheral blood stem cell transplant recipients.

The development of graft-versus-host disease (GVHD) can be modified by non-MHC factors. Based on our previous studies that showed an involvement of 70kD heat shock protein (hsp70) in the pathology of acute GVHD in a rat model, we determined serum levels of antibodies to hsp70, hsp90 and hsp60 in human recipients after allogeneic peripheral blood stem cell transplantation (PBSCT). Serum levels of these antibodies were correlated with GVHD status in the recipients. Twenty-nine recipients with high-risk haematological malignances, who received G-CSF mobilized allogeneic PBSCT from HLA matched family donors, were evaluated between 30 and 960 days after transplantation. Two recipients had no GVHD, 18 developed acute followed by chronic GVHD and nine developed only chronic GVHD. Patients with acute GVHD had a significant increase in IgM anti-hsp70 and/or anti-hsp90 early (30-90 days) after transplantation. In addition, an increase in IgM anti-hsp70 and/or anti-hsp90 antibodies preceded or accompanied chronic GVHD. Antibody levels returned to normal within the next 400 days in the majority of patients. Anti-hsp60 antibody levels were not different from control levels regardless of GVHD status. This study implies that the development of acute and/or chronic GVHD in humans is accompanied by an increase in anti-hsp70 and anti-hsp90 antibodies. Monitoring levels of anti-hsp70 and anti-hsp90 antibodies in stem cell transplant recipients may serve as a diagnostic tool and help to predict the onset of GVHD.

Adult↗

PubMed2002

Low-dose endobronchial gene transfer to ameliorate lung graft ischemia-reperfusion injury.

OBJECTIVE: This study was undertaken to determine whether low-dose endobronchial transfer to the donor of the gene for human interleukin 10 would decrease ischemia-reperfusion injury in lung transplantation. METHODS: Experiments used male Fischer rats. Donor animals underwent right thoracotomy. A catheter was introduced into the left main bronchus, and vector was instilled. Group I (n = 6) received 2 x 10(7) plaque-forming units of adenovirus encoding human interleukin 10, group II (n = 6) received an adenovirus control encoding beta-galactosidase, and group III (n = 6) received saline solution. After instillation the left main bronchus was clamped for 60 minutes. Lungs were removed 24 hours later and stored in low-potassium dextran glucose solution for 18 hours before left lung transplantation. Graft function was assessed at 24 hours immediately before the animals were killed. Ratio of wet to dry weight and tissue myeloperoxidase activity were measured. Transgenic expression of human interleukin 10 was evaluated by means of enzyme-linked immunosorbent assay and immunohistochemical assay. RESULTS: Arterial oxygenation was significantly improved in group I relative to groups II and III (257.6 +/- 59.7 mm Hg vs 114.6 +/- 66.9 mm Hg and 118.6 +/- 91.1 mm Hg, P =.008 and P =.007, respectively). Neutrophil sequestration, as measured by myeloperoxidase activity, was also significantly reduced in group I relative to groups II and III (0.141 +/- 0.025 vs 0.304 +/- 0.130 and 0.367 +/- 0.153 Delta optical density units/[min. mg protein], P =.029 and P =.004, respectively). Enzyme-linked immunosorbent assay and immunohistochemical assay demonstrated the expression of human interleukin 10 in transfected lungs only. CONCLUSIONS: Low-dose endobronchial transfer to the donor of the gene for human interleukin 10 ameliorated ischemia-reperfusion injury in rodent lung transplantation by improving graft oxygenation and reducing neutrophil sequestration. Only 2 x 10(7) plaque-forming units of adenoviral vector were required for functional transgenic expression. Endobronchial gene transfer to lung grafts may be a useful delivery route even at low doses.

Animals↗

PubMed2002

Recipient intramuscular cotransfection of naked plasmid transforming growth factor beta1 and interleukin 10 ameliorates lung graft ischemia-reperfusion injury.

OBJECTIVE: Multiple gene transfer might permit modulation of concurrent biochemical pathways involved in lung graft ischemia-reperfusion injury. In this study we analyzed whether recipient intramuscular naked plasmid cotransfection of transforming growth factor beta(1) and interleukin 10 would result in amelioration of lung graft ischemia-reperfusion injury. METHODS: Forty-eight hours before transplantation, 6 groups (n = 6) of F344 rats received intramuscular injection of naked plasmid encoding chloramphenicol acetyltransferase, chloramphenicol acetyltransferase plus beta-galactosidase, transforming growth factor beta(1), interleukin 10, or transforming growth factor beta(1) plus interleukin 10 or were not treated. Donor lungs were flushed and stored for 18 hours at 4 degrees C before transplantation. Twenty-four hours later, grafts were assessed immediately before the animals were killed. Arterial oxygenation, wet/dry ratio, myeloperoxidase, and proinflammatory cytokines (interleukin 1, tumor necrosis factor alpha, interferon gamma, and interleukin 2) were measured, and immunohistochemistry was performed. RESULTS: For lung graft function, the arterial oxygenation was considerably higher in the cotransfected group receiving transforming growth factor beta(1) plus interleukin 10 compared with that in all other groups (P < or =.03). The wet/dry ratio, reflecting lung edema, was reduced in the cotransfected group compared with that in control animals (nontreated, P <.02; chloramphenicol acetyltransferase, P <.03; chloramphenicol acetyltransferase plus beta-galactosidase, P <.01). Myeloperoxidase, which measures neutrophil sequestration, was also reduced with cotransfection compared with that seen in control animals (P < or =.03). All proinflammatory cytokines were decreased in the cotransfected group compared with those in all other groups (interleukin 1beta, P <.04; tumor necrosis factor alpha, P <.002; interferon gamma, P <.0001; interleukin 2, P <.03). These results indicate that cotransfection provides a synergistic benefit in graft function versus either cytokine alone, neutrophil sequestration, or inflammatory cytokine expression. Immunohistochemistry showed positive staining of transforming growth factor beta(1) plus interleukin 10 in type I and II pneumocytes and localized edema fluid. CONCLUSIONS: Recipient intramuscular naked plasmid cotransfection of transforming growth factor beta(1) and interleukin 10 provides a synergistic effect in ameliorating lung reperfusion injury after prolonged ischemia.

Analysis of Variance↗

PubMed2002

Intratracheal adenovirus-mediated gene transfer is optimal in experimental lung transplantation.

OBJECTIVE: Gene transfer to experimental lung grafts has been shown to reduce ischemia-reperfusion injury and acute rejection. The optimal delivery route should produce high lung expression with no inflammation and minimal systemic expression. The goal of this study was to determine the optimal gene transfer route for use in experimental lung transplantation. METHODS: F344 rats were injected with 2.9 x 10(10) plaque-forming units of adenovirus vector encoding beta-galactosidase through intratracheal, intravenous, intraperitoneal, or intramuscular delivery routes and killed 48 hours later. Gene expression was measured by means of enzyme-linked immunosorbent assay. RESULTS: Intratracheal delivery produces significantly greater gene expression in the lung (75,350 +/- 47,288 pg/100 microg of protein, P <.001 vs intravenous, intraperitoneal, and intramuscular routes) and minimal systemic expression (nonsignificant in serum, kidney, liver, spleen, and muscle vs that seen in control animals, P =.016 for heart). Immunohistochemistry staining showed beta-galactosidase expression in the bronchial epithelium of lungs transfected through the intratracheal route with mild inflammation. CONCLUSIONS: Intratracheal gene transfer provides significant expression in the lung with mild to no inflammation and minimal systemic expression. This delivery strategy has tremendous potential in experimental lung transplant models to reduce ischemia-reperfusion injury and acute allograft rejection and should be investigated further.

Adenoviridae↗

PubMed2002

Human dendritic cell mediated cytotoxicity against breast carcinoma cells in vitro.

Dendritic cells (DC) are an important subset of antigen-presenting cells characterized by their potent capacity to activate immunologically naïve T cells. However, their role in effector function in tumor resistance is less well characterized. We report here that activated human peripheral blood DC acquire a potent antitumor effect against breast cancer cell lines in vitro, leading to growth inhibition and apoptosis of the tumor cell. The antitumor effect of DC was augmented by proinflammatory stimuli induced by lipopolysaccharide (LPS) treatment. Tumor necrosis factor alpha (TNF-alpha) produced after DC activation was responsible for the antitumor activity of DC. Interferon-gamma, interleukin-15, or LPS treatment of DC markedly augmented the effector function of DC against most of the breast cells, indicating heterogeneity of the tumor and its susceptibility to cytokine-mediated damage. Treatment of LPS-activated DC or cell-free supernatant with anti-human TNF-alpha significantly reduces the antitumor effect against the tumor cells tested. These results suggest that in addition to their predominant role as immune regulatory cells, DC could serve as innate effector cells in tumor immunity.

Antibodies, Monoclonal↗