- Email: [email protected]
Treating Dense Deposit Disease by controlling the C3 convertase
Abstracts / Molecular Immunology 48 (2011) 1666–1733
1715
patient fibroblasts. Cos-7 cells were transfected either with pICNeo FH CA453T (mutant cDNA) or pICNeo FH CG453T (wild type cDNA). Again the secretion of this mutant FH was delayed. Mutant FH is mainly retained in the endoplasmic reticulum (ER) affecting its morphology in the patient fibroblasts when analyzed by both confocal and electronic microscopy. Since FH R127H retains its functional complement regulatory activity we attempted to accelerate its secretion by treating these cells with chemical chaperones 2 mol curcumin or 2 mmol 4-phenyl butyric acid. Both drugs improved in vitro the secretion of mutant FH R127H by fibroblasts after 24 h treatment. In conclusion, we suggest that these drugs should be investigated as a potential therapeutic option for this type of FH deficiency.
addressing, among others, its testing in vitro by measuring druginduced C activation in human serum, and modeling in pigs and dogs. A novel method for desensitization against HSRs to liposomal doxorubicin (Doxil) in pigs will also be described, along with other empirical approaches for preventing CARPA in patients.
doi:10.1016/j.molimm.2011.06.375
a
P156 Treating Dense Deposit Disease by controlling the C3 convertase Zhang a,∗ , H. Marsh b , S. Sethi c , R.J.H. Smith a a
University of Iowa, Iowa City, United States Celldex Therapeutics, Boston, United States c Mayo Clinic, Rochester, United States b
Dense Deposit Disease is a rare renal disease characterized by uncontrolled alternative pathway activation by fluid-phase dysregulation of the C3 convertase, which leads to the deposition of complement components in the glomerular basement membranes (GBMs) in affected patients. Inciting triggers are largely unknown and no specific treatments for DDD exist. Approximately half of DDD patients progress to end-stage renal disease within 10 years of diagnosis. We hypothesized that the control of C3 convertase activity would improve renal function in DDD patients, and since complement receptor 1 (CR1) is a potent complement regulator we tested TP10, a soluble derivative of human CR1, as a therapeutic reagent for DDD. Our in vitro studies show that TP10 binds to and prevents C3 convertase activity in all DDD sera even in presence of C3 nephritic factors – autoantibodies that bind to and stabilize C3 convertase. We next studied the therapeutic efficacy human TP10 in a DDD mouse model (CFH−/−/tg CR1). Our data show that TP10 arrests uncontrolled AP activation and normalizes complement C3 level in a short period time, leading to elimination of complement debris in the glomeruli. Long-term studies show no apparent autoantibody generation. These data suggest that TP10 is good therapeutic agent for DDD and that human clinical trials are warranted.
doi:10.1016/j.molimm.2011.06.377 P158 C5a in microdialysis fluid discriminates ischemia from rejection in liver grafts E.B. Thorgersen a,∗ , H. Haugaa b , A. Pharo a , T.I. Tønnessen b , T.E. Mollnes a Institute of Immunology, Oslo University Hospital, Rikshospitalet, Oslo, Norway b Dept. of Anesthesia and Intensive Care, Oslo University Hospital, Rikshospitalet, Oslo, Norway Close monitoring is crucial following liver transplantation. Standard monitoring through assessment of liver enzymes, Doppler Ultrasound and biopsies might imply delayed detection of rejection and ischemia. The aim of this study was to explore the ability of microdialysis to detect rejection and ischemia in liver grafts, with a particular focus on the potent complement activation product C5a and small-molecular inflammatory cytokines. Seventy-one liver transplants were monitored by 100 kDa cut-off microdialysis catheters. Microvials with dialysate were immediately frozen to −70 ◦ C. The inflammatory mediators were analyzed in one batch after study completion. Samples from patients with rejection (n = 12) and ischemia (n = 5) were compared to controls with clinical uneventful course (n = 17). C5a increased significantly (P = 0.004) only with ischemia, with a specificity of 1.00 (CI: 0.80–1.00) and sensitivity of 0.8 (CI: 0.28–0.99). Similar results were obtained for interleukin-1 receptor antagonist (IL-1ra) (P = 0.001), specificity 1.00 (CI: 0.80–1.00) and sensitivity 0.80 (CI: 0.28–0.99). On the contrary, interferon-inducible protein 10 (IP-10) increased significantly (P < 0.001) only with rejection, with a specificity of 0.94 (CI: 0.71–1.00) and sensitivity of 0.83 (CI: 0.52–0.98). IL-6 and IL-8 increased significantly with both conditions (P < 0.005), the complement-dependent IL-8 significantly more in ischemia. In conclusion, C5a and IL-1ra specifically reflected ischemia, and IP-10 specifically reflected rejection, whereas IL-6 and IL-8 were increased in both conditions. These data suggest that earlier graft saving treatment in liver transplants than the current standard of care may be initiated, and that the inflammatory mediators are useful to discriminate between rejection and ischemia.
doi:10.1016/j.molimm.2011.06.376 P157 Complement mediated hypersensitivity to nanomedicines
doi:10.1016/j.molimm.2011.06.378 P159
J. Szebeni ∗
Expression and function of CR1 and CR2 on B cells of rheumatoid arthritis patients
Nanomedicine Research and Education Center, Bay Zoltán Foundation for Applied Re, Budapest, Hungary
Kremlitzka a,∗ , Polgár b , Kiss b , Poór b , Bajtay a , Erdei a a
Many drugs or bioactive agents are recognized by the complement (C) system as foreign, leading to the development of a hypersensitivity reaction (HSR) referred to as C activation-related pseudoallergy (CARPA). While CARPA reactions are mostly mild and transient, in an occasional patient it can be severe or even lethal. Because a main manifestation of C activation in the body is cardiopulmonary distress, CARPA represents a major safety issue in cardiac patients. This presentation will review the immune pathomechanism and clinical aspects of liposome-induced CARPA
b
Eötvös Loránd University, Budapest, Hungary Institute of Rheumatology and Physiotherapy, Budapest, Hungary
The involvement of B cells, complement activation and subsequent immune complex deposition have all been implicated in the pathogenesis of rheumatoid arthritis (RA). While lower expression of complement receptor 1 (CR1) and 2 (CR2) on B cells of RA patients have been proven, the exact role of these receptors in B cell tolerance and autoimmunity is not fully known. To get a deeper insight
1715
patient fibroblasts. Cos-7 cells were transfected either with pICNeo FH CA453T (mutant cDNA) or pICNeo FH CG453T (wild type cDNA). Again the secretion of this mutant FH was delayed. Mutant FH is mainly retained in the endoplasmic reticulum (ER) affecting its morphology in the patient fibroblasts when analyzed by both confocal and electronic microscopy. Since FH R127H retains its functional complement regulatory activity we attempted to accelerate its secretion by treating these cells with chemical chaperones 2 mol curcumin or 2 mmol 4-phenyl butyric acid. Both drugs improved in vitro the secretion of mutant FH R127H by fibroblasts after 24 h treatment. In conclusion, we suggest that these drugs should be investigated as a potential therapeutic option for this type of FH deficiency.
addressing, among others, its testing in vitro by measuring druginduced C activation in human serum, and modeling in pigs and dogs. A novel method for desensitization against HSRs to liposomal doxorubicin (Doxil) in pigs will also be described, along with other empirical approaches for preventing CARPA in patients.
doi:10.1016/j.molimm.2011.06.375
a
P156 Treating Dense Deposit Disease by controlling the C3 convertase Zhang a,∗ , H. Marsh b , S. Sethi c , R.J.H. Smith a a
University of Iowa, Iowa City, United States Celldex Therapeutics, Boston, United States c Mayo Clinic, Rochester, United States b
Dense Deposit Disease is a rare renal disease characterized by uncontrolled alternative pathway activation by fluid-phase dysregulation of the C3 convertase, which leads to the deposition of complement components in the glomerular basement membranes (GBMs) in affected patients. Inciting triggers are largely unknown and no specific treatments for DDD exist. Approximately half of DDD patients progress to end-stage renal disease within 10 years of diagnosis. We hypothesized that the control of C3 convertase activity would improve renal function in DDD patients, and since complement receptor 1 (CR1) is a potent complement regulator we tested TP10, a soluble derivative of human CR1, as a therapeutic reagent for DDD. Our in vitro studies show that TP10 binds to and prevents C3 convertase activity in all DDD sera even in presence of C3 nephritic factors – autoantibodies that bind to and stabilize C3 convertase. We next studied the therapeutic efficacy human TP10 in a DDD mouse model (CFH−/−/tg CR1). Our data show that TP10 arrests uncontrolled AP activation and normalizes complement C3 level in a short period time, leading to elimination of complement debris in the glomeruli. Long-term studies show no apparent autoantibody generation. These data suggest that TP10 is good therapeutic agent for DDD and that human clinical trials are warranted.
doi:10.1016/j.molimm.2011.06.377 P158 C5a in microdialysis fluid discriminates ischemia from rejection in liver grafts E.B. Thorgersen a,∗ , H. Haugaa b , A. Pharo a , T.I. Tønnessen b , T.E. Mollnes a Institute of Immunology, Oslo University Hospital, Rikshospitalet, Oslo, Norway b Dept. of Anesthesia and Intensive Care, Oslo University Hospital, Rikshospitalet, Oslo, Norway Close monitoring is crucial following liver transplantation. Standard monitoring through assessment of liver enzymes, Doppler Ultrasound and biopsies might imply delayed detection of rejection and ischemia. The aim of this study was to explore the ability of microdialysis to detect rejection and ischemia in liver grafts, with a particular focus on the potent complement activation product C5a and small-molecular inflammatory cytokines. Seventy-one liver transplants were monitored by 100 kDa cut-off microdialysis catheters. Microvials with dialysate were immediately frozen to −70 ◦ C. The inflammatory mediators were analyzed in one batch after study completion. Samples from patients with rejection (n = 12) and ischemia (n = 5) were compared to controls with clinical uneventful course (n = 17). C5a increased significantly (P = 0.004) only with ischemia, with a specificity of 1.00 (CI: 0.80–1.00) and sensitivity of 0.8 (CI: 0.28–0.99). Similar results were obtained for interleukin-1 receptor antagonist (IL-1ra) (P = 0.001), specificity 1.00 (CI: 0.80–1.00) and sensitivity 0.80 (CI: 0.28–0.99). On the contrary, interferon-inducible protein 10 (IP-10) increased significantly (P < 0.001) only with rejection, with a specificity of 0.94 (CI: 0.71–1.00) and sensitivity of 0.83 (CI: 0.52–0.98). IL-6 and IL-8 increased significantly with both conditions (P < 0.005), the complement-dependent IL-8 significantly more in ischemia. In conclusion, C5a and IL-1ra specifically reflected ischemia, and IP-10 specifically reflected rejection, whereas IL-6 and IL-8 were increased in both conditions. These data suggest that earlier graft saving treatment in liver transplants than the current standard of care may be initiated, and that the inflammatory mediators are useful to discriminate between rejection and ischemia.
doi:10.1016/j.molimm.2011.06.376 P157 Complement mediated hypersensitivity to nanomedicines
doi:10.1016/j.molimm.2011.06.378 P159
J. Szebeni ∗
Expression and function of CR1 and CR2 on B cells of rheumatoid arthritis patients
Nanomedicine Research and Education Center, Bay Zoltán Foundation for Applied Re, Budapest, Hungary
Kremlitzka a,∗ , Polgár b , Kiss b , Poór b , Bajtay a , Erdei a a
Many drugs or bioactive agents are recognized by the complement (C) system as foreign, leading to the development of a hypersensitivity reaction (HSR) referred to as C activation-related pseudoallergy (CARPA). While CARPA reactions are mostly mild and transient, in an occasional patient it can be severe or even lethal. Because a main manifestation of C activation in the body is cardiopulmonary distress, CARPA represents a major safety issue in cardiac patients. This presentation will review the immune pathomechanism and clinical aspects of liposome-induced CARPA
b
Eötvös Loránd University, Budapest, Hungary Institute of Rheumatology and Physiotherapy, Budapest, Hungary
The involvement of B cells, complement activation and subsequent immune complex deposition have all been implicated in the pathogenesis of rheumatoid arthritis (RA). While lower expression of complement receptor 1 (CR1) and 2 (CR2) on B cells of RA patients have been proven, the exact role of these receptors in B cell tolerance and autoimmunity is not fully known. To get a deeper insight