Lingling Guo

University of Alabama at Birmingham, Birmingham, Alabama, United States

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Publications (12)40.82 Total impact

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    ABSTRACT: Renal ischemia-reperfusion injury is mediated by a complex cascade of events, including the immune response, that occur secondary to injury to renal epithelial cells. We tested the hypothesis that heme oxygenase-1 (HO-1) expression, which is protective in ischemia-reperfusion injury, regulates trafficking of myeloid-derived immune cells in the kidney. Age-matched male wild-type (HO-1(+/+)), HO-1-knockout (HO-1(-/-)), and humanized HO-1-overexpressing (HBAC) mice underwent bilateral renal ischemia for 10 minutes. Ischemia-reperfusion injury resulted in significantly worse renal structure and function and increased mortality in HO-1(-/-) mice. In addition, there were more macrophages (CD45(+) CD11b(hi)F4/80(lo)) and neutrophils (CD45(+) CD11b(hi) MHCII(-) Gr-1(hi)) in HO-1(-/-) kidneys than in sham and HO-1(+/+) control kidneys subjected to ischemia-reperfusion. However, ischemic injury resulted in a significant decrease in the intrarenal resident dendritic cell (DC; CD45(+)MHCII(+)CD11b(lo)F4/80(hi)) population in HO-1(-/-) kidneys compared with controls. Syngeneic transplant experiments utilizing green fluorescent protein-positive HO-1(+/+) or HO-1(-/-) donor kidneys and green fluorescent protein-negative HO-1(+/+) recipients confirmed increased migration of the resident DC population from HO-1(-/-) donor kidneys, compared to HO-1(+/+) donor kidneys, to the peripheral lymphoid organs. This effect on renal DC migration was corroborated in myeloid-specific HO-1(-/-) mice subjected to bilateral ischemia. These mice also displayed impaired renal recovery and increased fibrosis at day 7 after injury. These results highlight an important role for HO-1 in orchestrating the trafficking of myeloid cells in AKI, which may represent a key pathway for therapeutic intervention. Copyright © 2015 by the American Society of Nephrology.
    Journal of the American Society of Nephrology 02/2015; DOI:10.1681/ASN.2014080770 · 9.47 Impact Factor
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    ABSTRACT: Kidney allograft rejection is associated with infiltration of inflammatory CD11b+ leukocytes. A CD11b agonist leukadherin-1 (LA1) increases leukocyte adhesion, preventing their transmigration and tissue recruitment in vivo. Here, we test the extent to which LA1-mediated activation of CD11b/CD18 enhances kidney allograft survival in a mouse model of fully MHC-mismatched orthotopic kidney transplantation, where C57BL/6J (H-2(b)) recipients received kidney allografts from Balb/c mice (H-2(d)). Isograft control recipients received a kidney from a littermate. Control isograft and allograft recipients were treated daily with cyclosporine (CsA) for 2 weeks, while the test group received CsA therapy and daily LA1 injections during week 1 and alternate days during weeks 2-8. LA1 treatment reduced interstitial leukocyte infiltration in the allograft, reduced neointimal hyperplasia and glomerular damage, and prolonged graft survival from 48.5% (CsA only) to 100% (CsA and LA1) on day 60. Serum creatinine levels showed significantly improved kidney function in LA1-treated mice compared to CsA-treated allograft controls [0.52 ± 0.18 mg/dL vs 0.24 ± 0.07 mg/dL (n = 5), respectively]. Furthermore, combination therapy reduced macrophage infiltration and increased the frequency of FoxP3 + Tregs in the allograft. These findings indicate a crucial role for CD11b/CD18 in the control of leukocyte migration to the transplanted kidney and identify integrin agonist LA1 as a novel potential therapeutic agent for kidney transplantation.
    11/2014; 1:45. DOI:10.3389/fmed.2014.00045
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    ABSTRACT: BACKGROUND: Human cytomegalovirus (CMV) infection is associated with inferior survival in renal transplant patients, and ganciclovir (GCV) prophylaxis is associated with improved survival. In a murine CMV (MCMV) renal transplantation model, ganciclovir prophylaxis improved innate infiltrates and allograft damage during the period of prophylaxis. In this study, late effects were examined after the discontinuation of prophylaxis. METHODS: MCMV D+/R- and D-/R- allogeneic transplants were performed with cyclosporine immunosuppression. One D+/R- cohort received ganciclovir prophylaxis for 14 days after transplantation followed by 28 days without ganciclovir. At 42 days after transplantation, grafts were analyzed for histologic tissue damage and immune infiltrates. Another D+/R- cohort was treated with anti-NK1.1 antibodies for 14 days after transplantation and compared with animals without natural killer (NK) cell depletion. RESULTS: At day 42, MCMV-infected transplants had higher damage scores (15.6±0.6) compared with uninfected transplants (8.3±0.9; P<0.01), which improved in ganciclovir-treated allografts (9.5±1.4). MCMV-infected grafts contained greater frequencies of NK cell and myeloid infiltrates compared with uninfected grafts (P<0.05), which decreased in the ganciclovir-treated grafts. NK cell depletion improved allograft histology of MCMV-infected grafts. CONCLUSIONS: MCMV infection exacerbates late renal allograft damage and is associated with NK and myeloid cell infiltrates. Ganciclovir prophylaxis reduces allograft injury and NK cell and myeloid infiltrates even after the cessation of prophylaxis. NK cell depletion in MCMV-infected transplants also improves histology. These results suggest that ganciclovir prophylaxis may have a long-term beneficial effect on CMV-infected renal allografts and suggest a potential role for NK cells in the pathogenesis of CMV-associated allograft injury.
    Transplantation 12/2012; 95(1). DOI:10.1097/TP.0b013e3182782efc · 3.78 Impact Factor
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    ABSTRACT: Background: Cytomegalovirus (CMV) infection is associated with adverse outcomes in renal transplantation, but the role of antiviral innate effectors in this pathogenesis has not been investigated. Clinically, renal transplant patients with natural killer (NK) cell killer immunoglobulin-like receptor (KIR) ligand mismatches have inferior 10-year graft survival, suggesting that NK activation may contribute to poor allograft outcome. Murine CMV (MCMV) infected renal allografts manifest greater NK infiltrates and more advanced tissue injury compared to uninfected grafts at 14 days post-transplant. NK activation has not been investigated in the pathogenesis of long-term CMV associated renal allograft injury. Methods: Murine CMV (MCMV) infected Balb/c donor kidneys were transplanted orthotopically into uninfected C57Bl/6 recipients ( D+/R- CMV group) with cyclosporine immunosuppression; control transplants comprised uninfected Balb/c donors (D-/R- control group). Ganciclovir (GCV) prophylaxis was given for 14 days post-transplant to one cohort of MCMV D+/R- transplants (GCV group). At day 42 post-transplant, allograft immune infiltrates were examined by flow cytometry, and histology was scored by a veterinary pathologist blinded to sample identity (maximum score 27). Results: At day 42, CMV transplants had higher damage scores (average 14.5) compared to uninfected transplants (average 10.25) (p<0.05). Allografts with GCV prophylaxis had lower damage scores (average 9.5) which were statistically similar to control uninfected transplants (p=0.58). CMV infected and uninfected grafts had similar frequencies of CD4+, CD8+, and CD19+ lymphocytes, but CMV infected grafts contained higher frequencies of CD3-/CD49b+ NK cells and CD11b+/Gr-1+ myeloid cells compared to uninfected grafts. GCV prophylaxis reduced the frequency of CD49b+ and Gr-1+ infiltrates. Conclusion: CMV induces long-term NK infiltrates and late histologic injury in an animal model. GCV prophylaxis modulates both histologic injury and innate infiltrates even after cessation of prophylaxis. Virus-induced NK cell activation may represent a mechanism of ongoing allograft injury that is not currently targeted by current immunosuppressants in transplantation.
    IDWeek 2012 Meeting of the Infectious Diseases Society of America; 10/2012
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    ABSTRACT: Although short-term outcomes in kidney transplantation have improved dramatically, long-term survival remains a major challenge. A key component of long-term, chronic allograft injury in solid organ transplants is arteriosclerosis characterized by vascular neointimal hyperplasia and inflammation. Establishing a model of this disorder would provide a unique tool not only to identify mechanisms of disease but also to test potential therapeutics for late graft injury. To this end, we utilized a mouse orthotopic renal transplant model in which C57BL/6J (H-2b) recipients were given either a kidney allograft from a completely mismatched Balb/cJ mouse (H-2d) or an isograft from a littermate. A unilateral nephrectomy was performed at the time of transplant followed by a contralateral nephrectomy on post-transplant day 7. Recipients were treated with daily cyclosporine subcutaneously for 14 days and then studied 8 and 12 weeks post transplantation. Renal function was significantly worse in allograft compared with isograft recipients. Moreover, the allografts had significantly more advanced tubulointerstitial fibrosis and profound vascular disease characterized by perivascular leukocytic infiltration and neointimal hyperplasia affecting the intrarenal blood vessels. Thus, we describe a feasible and reproducible murine model of intrarenal transplant arteriosclerosis that is useful to study allograft vasculopathy.Kidney International advance online publication, 8 August 2012; doi:10.1038/ki.2012.277.
    Kidney International 08/2012; 82(11). DOI:10.1038/ki.2012.277 · 8.52 Impact Factor
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    ABSTRACT: Vascular procedures involving anastomoses in the mouse are generally thought to be difficult and highly dependent on the skill of the individual surgeon. This is largely true, but there are a number of important principles that can reduce the difficulty of these procedures and enhance reproducibility. Orthotopic aortic transplantation is an excellent procedure in which to learn these principles because it involves only two end-to-end anastomoses, but requires good suturing technique and handling of the vessels for consistent success. This procedure begins with the procurement of a length of abdominal aorta from a donor animal, followed by division of the native aorta in the recipient. The procured aorta is then placed between the divided ends of the recipient aorta and sutured into place using end-to-end anastomoses. To accomplish this objective successfully requires a high degree of concentration, good tools, a steady hand, and an appreciation of how easily the vasculature of a mouse can be damaged, resulting in thrombosis. Learning these important principles is what occupies most of the beginner's time when learning microsurgery in small rodents. Throughout this protocol, we refer to these important points. This model can be used to study vascular disease in a variety of different experimental systems(1-8). In the context shown here, it is most often used for the study of post-transplant vascular disease, a common long-term complication of solid organ transplantation in which intimal hyperplasia occurs within the allograft. The primary advantage of the model is that it facilitates quantitative morphometric analyses and the transplanted vessel lies contiguous to the endogenous vessel, which can serve as an additional control(9). The technique shown here is most often used for mice weighing 18-25 grams. We have accumulated most of our experience using the C57BL/6J, BALB/cJ, and C3H/HeJ strains.
    Journal of Visualized Experiments 01/2012; DOI:10.3791/4338
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    ABSTRACT: Background: Human cytomegalovirus (HCMV) infection remains a serious complication in solid organ transplantation and has been associated with poor renal allograft outcome in seroepidemiologic studies. However, the pathogenesis of HCMV mediated allograft damage has not been fully defined. Methods: A murine model for cytomegalovirus in renal transplantation was used, in which murine CMV (MCMV) infected BALB/c donor organs were transplanted into uninfected C57BL/6 wildtype or antibody deficient C57BL/6-Igh-6tm1Cgn (Ig-KO) recipients without the removal of the contralateral native kidney or the need for immunosuppression. MCMV-specific or control serum was given to Ig-KO recipients to assess the role of anti-MCMV antibodies on allograft damage. In independent studies, complement was depleted in MCMV recipients via cobra venom factor 1, to determine the involvement of intragraft complement activation in graft injury. Results: Allograft histology 14 days post transplantation demonstrated that MCMV infected allografts (MCMV) exhibit accelerated damage compared to uninfected allografts (Mock), associated with intragraft IgG antibody deposition and complement C3 fixation as early as 3 days post transplantation. Flow cytometry analyses showed that MCMV allografts contain significantly less cellular immune infiltrates compared to Mock grafts at 14 days post transplantation. Despite the presence of MCMV in the contralateral native kidneys, histology of the MCMV native kidneys remained normal with no significant immune infiltrates, antibody deposition or C3 fixation. Histology of Ig-KO allografts showed reduced graft damage compared to the MCMV allografts. Passive transfer of MCMV antiserum, but not control serum, into Ig-KO recipients restores intragraft IgG antibody deposition and C3 fixation. Consistent with this result, histology of allografts from complement depleted MCMV recipients demonstrated less graft injury despite intragraft antibody deposition. Conclusion: These results suggest that MCMV accelerated renal allograft damage is associated with intragraft MCMV-specific IgG antibody deposition leading to complement activation, and that the allogeneic response is required for enhanced MCMV associated allograft damage.
    Infectious Diseases Society of America 2011 Annual Meeting; 10/2011
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    ABSTRACT: Prophylactic ganciclovir (GCV) is used in high-risk renal transplant patients to prevent acute cytomegalovirus (CMV) disease, but its impact on inflammation within the allograft itself remains undefined. To study the effect of GCV prophylaxis on allograft inflammation, murine CMV (MCMV)-infected allografts were analyzed in a murine donor positive/recipient negative allogeneic renal transplantation model by flow cytometry and immunofluorescent staining. By flow cytometry, CD45+ leukocyte infiltrates were more abundant in MCMV-infected allografts at 14 days posttransplant compared with uninfected grafts (P<0.01) and decreased in the presence of GCV (P<0.05). CD11c+ dendritic cells, Gr-1+ myeloid cells, CD204+ macrophages, and CD49b+ natural killer cells were reduced in GCV-treated allografts compared with MCMV-infected grafts without GCV treatment (P<0.05). However, GCV failed to reduce these cell types to levels found in MCMV-uninfected allografts. By day 7 after cessation of GCV prophylaxis, dendritic cells, macrophages, and natural killer cells increased in number and became statistically indistinguishable from numbers of cells found in MCMV-infected allografts without GCV. GCV treatment did not affect the numbers of CD4+, CD8+, or CD19+/B220+ lymphocytes infiltrating the allografts. Infiltrates were confirmed histologically by immunofluorescent staining for CD3+ and CD11b+ cells. In this model, MCMV-infected allografts developed significantly greater innate and adaptive leukocytic infiltrates compared with uninfected grafts. GCV attenuated the MCMV-associated innate leukocyte infiltrates in infected allografts but not the lymphocytic infiltrates. The attenuated innate response was limited to the period of GCV prophylaxis.
    Transplantation 08/2011; 92(7):759-66. DOI:10.1097/TP.0b013e31822c6e89 · 3.78 Impact Factor
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    ABSTRACT: Early pancreatic cancer response following cetuximab and/or irinotecan therapies was measured by serial dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) before and during therapy. Groups 1 to 4 (n  =  6/group) of SCID mice bearing orthotopic pancreatic adenocarcinoma xenografts expressing luciferase were treated with phosphate-buffered saline, cetuximab, irinotecan, or cetuximab combined with irinotecan, respectively, twice weekly for 3 weeks. DCE-MRI was performed on days 0, 1, 2, and 3 after therapy initiation, whereas anatomic magnetic resonance imaging was performed on days 0, 1, 2, 3, 6, and 13. Bioluminescence imaging was performed on days 0 and 21. At day 21, all tumors were collected for further histologic analyses (Ki-67 and CD31 staining), whereas tumor dimensions were measured by calipers. The Ktrans values in the 0.5 mm-thick peripheral tumor region were calculated, and the changes in Ktrans during the 3 days posttherapy were compared to tumor volume changes, bioluminescent signal changes, and histologic findings. The Ktrans changes in the peripheral tumor region after 3 days of therapy were linearly correlated with 21-day decreases in tumor volume (p < .001), bioluminescent signal (p  =  .050), microvessel densities (p  =  .002), and proliferating cell densities (p  =  .001). This study supports the clinical use of DCE-MRI for pancreatic cancer patients for early assessment of an anti-epidermal growth factor receptor therapy combined with chemotherapy.
    Molecular Imaging 06/2011; 10(3):153-67. DOI:10.1158/1538-7445.AM10-641 · 2.19 Impact Factor
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    ABSTRACT: Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) measured the early vascular changes after administration of TRA-8, bevacizumab, or TRA-8 combined with bevacizumab in breast tumor xenografts. Groups 1-4 of nude mice bearing human breast carcinoma were injected with phosphate-buffered saline, TRA-8, bevacizumab, and TRA-8 + bevacizumab on day 0, respectively. DCE-MRI was performed on days 0, 1, 2, and 3, and thereafter tumors were collected for terminal deoxynucleotidyl transferase-mediated dUT nick end labeling and CD31 staining. DCE-MRI measured a significant K (trans) change within 3 days after TRA-8 therapy that correlated with tumor growth arrest, which was not shown with statistical significance by histopathology at these early time points posttreatment. The K (trans) changes followed quadratic polynomial curves. DCE-MRI detected significantly lower K (trans) levels in breast tumor xenografts following TRA-8 monotherapy or combined therapy with bevacizumab.
    Molecular imaging and biology: MIB: the official publication of the Academy of Molecular Imaging 04/2010; 13(1):94-103. DOI:10.1007/s11307-010-0320-2 · 2.87 Impact Factor
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    ABSTRACT: Heme oxygenase-1 (HO-1) catalyzes the conversion of heme into carbon monoxide (CO), iron, and biliverdin. In preliminary studies, we observed that the absence of HO-1 in aortic allograft recipients resulted in 100% mortality within 4 days due to arterial thrombosis. In contrast, recipients normally expressing HO-1 showed 100% graft patency and survival for more than 56 days. Abdominal aortic transplants were performed using Balb/cJ mice as donors and either HO-1(+/+) or HO-1(-/-) (C57BL/6xFVB) mice as recipients. Light and electron microscopy revealed extensive platelet-rich thrombi along the entire length of the graft in HO-1(-/-) recipients at 24 hours. Treatment of recipients with CORM-2, a CO-releasing molecule (10 mg/kg of body weight intravenously), 1 hour prior and 1, 3, and 6 days after transplantation, significantly improved survival (62% at >56 days, P < 0.001) compared with HO-1(-/-) recipients treated with inactive CORM-2 (median survival 1 day). Histological analyses revealed that CO treatment markedly reduced platelet aggregation within the graft. Adoptive transfer of wild-type platelets to HO-1(-/-) recipients also conferred protection and increased survival. Aortic transplants from either HO-1(-/-) or HO-1(+/+) C57BL/6 donors into HO-1(+/+) (Balb/cJ) mice did not develop arterial thrombosis, surviving more than 56 days. These studies demonstrate an important role for systemic HO-1/CO for protection against vascular arterial thrombosis in murine aortic allotransplantation.
    American Journal Of Pathology 07/2009; 175(1):422-9. DOI:10.2353/ajpath.2009.081033 · 4.60 Impact Factor
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    ABSTRACT: Extracorporeal photopheresis (ECP) is used to treat recurrent severe rejection in clinical heart and lung recipients. The mechanisms of the salutary effects of ECP are poorly understood, but appear to involve regulation of T-cell-mediated alloreactive responses, possibly by induction of regulatory T cells. We created a mouse model of ECP to determine the effects of ECP on T-cell responses in vivo and the contribution of CD4(+)CD25(+) T cells. In this study, 1 x 10(7) splenocytes were treated with 8-methoxypsoralen (8-MOP, 200 ng/ml), followed by ultraviolet A (UVA) irradiation (2 J/cm(2), 350 nm), and then injected intravenously into syngeneic mice. Thirty minutes later, the treated animals received heterotopic cardiac allografts with no immunosuppression. Treated graft recipients were analyzed to determine the effect of ECP on graft survival, deletion of allospecific T cells, and the frequency and in vivo suppressive activity of CD4(+)CD25(+) T cells. ECP extends cardiac allograft survival in at least two different strain combinations. For CBA/Ca recipients of C57BL/6 allografts, median survival time (MST) in ECP-treated animals was 16 days vs 10 days in graft recipients treated with cells exposed only to 8-MOP (p = 0.04). The frequency of splenic CD4(+)CD25(+) cells expressing FoxP3(+) increased 2-fold in ECP-treated CBA/Ca mice (82.6 +/- 5.2%, n = 4) relative to untreated mice (44.9 +/- 4.5%, n = 4, p < 0.001). Adoptive transfer of 3 x 10(5) sorted CD4(+)CD25(+) splenocytes from ECP-treated graft recipients to untreated cardiac allograft recipients 30 minutes after transplantation resulted in extended graft survival compared with animals that received the same number of CD4(+)CD25(+) splenocytes from cardiac allograft recipients not treated with ECP (MST: 24 days vs 13 days, respectively, p = 0.001). Analyses of 5,6-carboxy-fluorescein-succinimidyl-ester (CFSE)-labeled H-2K(b)-specific T cells in the spleen and lymph node showed no evidence of peripheral deletion after ECP treatment. ECP extends graft survival even in fully histoincompatible strain combinations with no immunosuppression. It increases the frequency of FoxP3(+)CD4(+)CD25(+) splenic T cells, and its effects can be transferred to untreated recipients using minimal numbers of CD4(+)CD25(+) T cells, indicating that CD4(+)CD25(+) T cells may play a key role in the immunomodulatory effects of ECP.
    The Journal of heart and lung transplantation: the official publication of the International Society for Heart Transplantation 06/2008; 27(6):616-22. DOI:10.1016/j.healun.2008.02.015 · 5.61 Impact Factor