Optimized AAV package and experimental application of recombinant AAV8/hFⅧ for gene therapy on hemophilia A mice / 中华血液学杂志

Objective@#To evaluate the effects of adeno-associated virus (AAV) carrying hFⅧ by serotype 8 (AAV8/hFⅧ) on hemophilia A (HA) mice by gene therapy strategy.@*Methods@#pAAV-CB-EGFP, pH22 (serotype 2) and pfΔ6 (adenovirus helper) were used to package AAV into HEK-293 cells in different conditions (ratios of cells to plasmids). The efficiency of transfection and infection were evaluated using immunofluorescence microscope to seek an optimized package condition. pAAV-TTR-hFⅧ, pH 28 (serotype 8) and pfΔ6 were applied to package AAV8/hFⅧ in HEK-293 cells using the optimized package condition. The purified AAV8/hFⅧ were intravenously injected into HA mice and the effects of gene therapy were estimated.@*Results@#The efficiency of package was evaluated according to the amount and intensity of enhanced green fluorescent protein (EGFP) under immunofluorescence microscope. Four package conditions including 10 cm-dish to transfect 10 μg plasmids, 20 cm-dish to 20 μg, 30 μg and 40 μg plasmids were employed, and the condition of 20 cm-dish to transfect 20 μg plasmids reached the highest transfection efficiency at 24 h, 48 h and 72 h after transfection. The small scale AAV-EGFP was packaged using the optimized condition and an AAV crude extract was harvested by a freeze-thaw method. HEK-293 and 16095 cells were infected by the AAV crude extract, and the preferential infection efficiency was recognized in 16095 cells under immunofluorescence microscope. Then, AAV8/hFⅧ was packaged and purified based on the optimized transfection condition, and the high purity of AAV8/hFⅧ was detected by Western blot. Fractions of AAV8/hFⅧ at the dose of 8×1012 vg/kg were injected into HA mice through tail vein, an eye-bleeding was performed at every two weeks, and the activity of FⅧ was measured by aPTT assay. Results showed that the activity of FⅧ maintained at the therapeutic level and lasted up to 12 weeks after injection.@*Conclusion@#The purified AAV8/hFⅧ based on the optimized package condition could play a role in HA mice gene therapy, and the long-term therapeutic effects of AAV8/hFⅧ were observed in vivo.

A rare case of B-lymphoproliferative disorder with villous lymphocytes harboring t(8;14)(q24;q32) translocation / 医学前沿

Splenic lymphoma with villous lymphocytes (SLVL) or splenic marginal zone lymphoma with circulating villous lymphocytes is rare, and prolymphocytic transformation of SLVL is rarer. At present, only one case of SLVL with t(8;14)(q24;q32) translocation has been reported. In this study, we report a case of B-lymphoproliferative disorder with villous lymphocytes harboring t(8;14)(q24;q32) chromosome translocation that we inclined to SLVL with a prolymphocytic transformation. A 73-year-old female showed marked hepatosplenomegaly and high lymphocytosis (lymphocytes > 200 × 10/L). The abnormal lymphocytes had short coarse villi and round nuclei with prominent nucleoli. The immunophenotypes showed CD19, CD20, HLA-DR, CD22, CD5, Kappa, CD25, CD71, Lambda, CD7, CD10, CD23, CD34, CD33, CD13, CD14, CD117, CD64, CD103, and CD11c. The karyotype showed complex abnormality: 46XX,+ 3,-10, t(8;14)(q24; q32)[11]/46XX[9]. The cytoplasmic projection, immunological characteristics, and trisomy 3 chromosome abnormality supported the diagnosis of SLVL. However, the presence of prominent nucleoli and high lymphocytosis suggested prolymphocytic transformation, probably as a result of t(8,14) chromosome translocation. In this report, we described an unusual case of B-lymphoproliferative disorder with villous lymphocytes harboring t(8;14)(q24;q32) translocation, which could provide help in the diagnosis and differential diagnosis of B-lymphocytic proliferative diseases.

The phenotypic and genotypic diagnosis of three Chinese patients with von Willebrand disease / 中华内科杂志

Objective To analyze the phenotype and genotype of three patients with yon Willebrand disease (vWD),and to explore its molecular pathogenesis.Methods Bleeding time (BT),APTT,ristocetin induced platelet aggregation (RIPA),von Willebrand factor (vWF):ristocetin cofactor (Rco)(vWF∶ Rco),vWF antigen (vWF∶ Ag),vWF activity (vWF∶ A) test,vWF collagen binding assay (vWF∶ CB) and multimer analysis were detected for phenotype diagnosis.The dynamic process of blood coagulation was evaluated by using the thrombelastography.Genomic DNA was extracted from the peripheral blood.The vWF gene mutation was detected by sequencing.Results APTT,BT were prolonged in the three probands.Plasma vWF∶ Rco,vWF∶ Ag,vWF∶ A and vWF∶ CB were decreased in different degrees.RIPA was reduced in probands B and C.vWF multimer analysis found the lost of the large molecular weight multimers in proband B,while basically normal in probands A and C.The dynamic process of blood coagulation of proband C presented obvious hypocoagulability by using the thrombelastography.Heterozygous missense mutation g.106782G ＞ T resulting in Cys1130Phe in exon 26,g.110988G ＞ A resulting in Gly1579Arg in exon 28 and g.110373C ＞T resulting in Arg1374Cys in exon 28 were found in the probands A,B and C,respectively.Conclusion Three probands were diagnosed as type 1,type 2A or type 2MvWD by phenotype detection.Heterozygous missense mutation Cys1130Phe,Gly1579Arg and Arg1374Cys induced vWD of three probands,respectively.

Compound heterozygous mutations of a family with inherited hypofibrinogenemia / 中华检验医学杂志

Objective To analyze the phenotype and genotype of a Chinese family with inherited hypofibrinogenemia,and to investigate its molecular mechanism.Methods Peripheral blood was collected from seven people of this family and then plasma was separated.Activated partial thromboplastin time ( APTT),prothrombin time ( PT),thrombin time ( TT),reptilase time ( RT),the activities of antithrombin( AT∶ A ),protein C ( PC ∶ A ) and protein S ( PS ∶ A ) were tested.The activity and antigen of plasma fibrinogen were analyzed by Clauss method and immunoturbidimetry method,respectively.The fibrinogen peptide chain of the proband was semiquantitatively assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE).Thrombin generation test was performed by calibrated automated thromhogram.The dynamic process of blood coagulation was evaluated by the thrombelastography (TEG).Genomic DNA was extracted from the peripheral blood.The sequences of all the exons and exon-intron boundaries of the three fibrinogen genes FGA,FGB and FGG were amplified by polymerase chain reaction ( PCR ) and analyzed by direct sequen(c)ing.Results The activity and the antigen levels of the proband' s plasma fibrinogen were reduced to 0.48 g/L and 0.68 g/L,respectively.TT prolonged to 29.2 s and RT prolonged to 75.8 s.The assays of SDS-PAGE showed no abnormal molecular weight of fibrinogen.Peak height of thrombin generation was reduced to 249.93 nmol/L and endogenous thrombin potential was reduced to 1007.0 nmol · L-1 · min.Hypocoagulability state of the whole blood was found by TEG test.The coagulation index was - 8.6.The proband was diagnosed as inherited hypofibrinogenemia by phenotype analysis.Two mutations (Gln143Pro and g.4642delC) were found in the proband's fibrinogen Aa-chain gene,Gln143Pro came from her mother and g.4642delC came form her father.Conclusion Compound Heterozygous Mutations (Gln143Pro and g.4642delC ) of fibrinogen Aa-chain causes the proband congenital hypofibrinogenemia.

Recent advances in the understanding of the molecular mechanisms regulating platelet integrin αIIbβ3 activation

Integrins are allosteric cell adhesion receptors that cycle from a low to a high affinity ligand binding state, a complex process of receptor activation that is of particular importance in blood cells such as platelets or leukocytes. Here we highlight recent progress in the understanding of the molecular pathways that regulate integrin activation in platelets and leukocytes, with a special focus on the structural changes in platelet integrin αIIbβ3 brought about by key intracellular proteins, namely talin and kindlins, that are of crucial importance in the regulation of integrin function. Evidence that the small GTPase Rap1 and its guanine exchange factor CalDAG-GEF1, together with RIAM, a Rap1GTP adaptor protein, promote the interaction of talin with the integrin β subunit, has greatly contributed to fill the gap in our understanding of the signaling pathway from G-coupled agonist receptors and their phospholipase C-dependant second messengers, to integrin activation. Studies of patients with the rare blood cell disorder LAD-III have contributed to the identification of kindlins as new co-regulators of the talin-dependent integrin activation process in platelets and leukocytes, underlining the relevance for the in-depth investigation of patients with rare genetic blood cell disorders.

Study of molecular mechanisms of hereditary protein C deficiency in four Chinese families / 中华检验医学杂志

Objective To investigate the phenotype, genotype and molecular mechanisms in four Chinese pedigrees with venous thrombosis caused by hereditary PC deficiency. Methods The plasma activity of PC: A, TPS: A and FPS: A of the probands and their family members were detected with chromogenic and coagulation assay. The antigen of PC and FPS were identified with ELISA. Thrombin generation tests were applied to indicate the coagulation status. All of the nine exons and intron-exon boundaries of PC gene and PS gene were amplified by PCR and directly sequenced for mutaiton investigation. Results Compound heterozygous mutations of L-34P, K150del and A209V with 36% of PC: A and 57% of PC: Ag were identified in proband 1. PC: A was 46% , PC: Ag was 64. 4% while TPS: A, FPS: A and FPS: Ag were 36% , 19.5% and 20.9% respectively in proband 2. Two independent heterozygous mutations of R147W in PC gene inherited from his mother and T519stop in PS gene inherited from his father were identified. The anticoagulant activity of Proband 2 and his parents were declined in thrombin generation assay. In proband with PS defeciency and his father, the inhibition of thrombin generation capacity was decreased with exogenous APC, while his mother did not have significant difference. In Proband 3, PC: A was 32% while PC: Ag was 48.42% . Two independent mutations of R147W and R178W in Exon 7 were detected. Compound heterozygous mutations of R178W and D255H,with 21% of PC : A and 18. 36% of PC: Ag were identified in the Proband 4. Conclusions Hereditary PC deficiency or combined PC and PS deficiency result in venous thrombosis in four Chinese families. Mutants of L-34P, A209V, R178W, R147W and D255H might be the molecular mechanisms of PC deficiency.

Genetic diagnosis of four combined deficiency of factor Ⅴ and Ⅷ patients / 中华检验医学杂志

Objective To investigate the genetic diagnosis and molecular pathogenesis of four patients with combined deficiency of coagulation factor Ⅴ and Ⅷ and their family members. Methods The APPT, FT, FⅤ: C, FⅧ: C were detected for phenotypic diagnosis. Thrombin generation assay was applied to determine the generation condition of thrombin in patients and healthy controls. Cenomic DNA was extracted from peripheral blood using the TianGen RelaxCene Blood DNA System;amniotic fluid DNA was extracted with phenol-ethyl ether method. The LMAN1 and MCFD2 genes were analyzed by PCR. Gene mutations were detected with nucleotid sequences by using end-labeling dideoxy method. Results The APTT of Proband 1 was significantly prolonged to 88. 2s and her PT was prolonged to 19. 6 s. The combined deficiency was identified with FⅧ (FⅧ: C 24. 2% ) and FV(FⅤ: C 9. 1% ). Proband 2 and 3 were sisters. The coagulation studies revealed that both of them had prolonged APTT (71.6 s and 74.6 s respectively) and PT (22. 1 s and 18. 3 s respectively). The combined deficiency of FⅤ (FⅤ: C 7. 6% and 14. 5% respectively) and FⅧ( FⅧ: C 25% and 19.6% respectively) were identified. Proband 4 was detected to have the prolonged APTT (70.3 s),PT (18.2 s) and the deficiency of FⅤ(FⅤ: C 9. 4% ) and FⅧ (15. 7% ). The remaining phenotype indicators test of the 4 probands were normal. The diagnosis for the 4 probands was combined deficiency of factor Ⅴ and Ⅷ. The proband 1 was detected to have compound heterozygous mutations in LMAN1 gene while having the LMAN1 and MCFD2 direct gene sequencing. One mutation was a small insertion located on exon 8 [ nt912insA (X71661. 1)] that resulted in p. 305frameshiftX20 and her mother was detected to have the same heterozygous mutation on the the locus. The other mutation was located on exon 11: nt1366C > CT ( X71661. 1 ) , p. 456Arg > Stop which was inherited from her father. Amniocyte DNA was detected to have only one heterozygous mutaion [nt1366C > CT (X71661. 1) , 456Arg > Stop] inherited from the father. No mutation in MCFD2 gene was found in proband 1 and her parents. The analysis of the MCFD2 gene in proband 2 and 3 revealed a novel homozygous single base substitution (nt411T>C) in exon 4, which results in the exchange of the amino acid isoleucine by the amino acid threonine at amino acid position 136 (p. Ile136Thr). Sequencing of the whole LMAN1 gene showed that the proband 4 had one homozygous nonsence mutation in the exon 5 of the LMAN1 ( nt615C >T,p. 202 Arg> Stop). All of the 4 probands with combined deficiency of FⅤ and FⅧ showed declined endogenous thrombin potential in the thrombin generation tests. Conclusion The combined deficiency of FⅤ and FⅧ in the proband 1 results from the compound heterozygous mutations ( nt1366C > CT and nt912insA) in LMAN1 gene, which are inherited from her parents respectively. The prenatal genetic investigation for the patient mother with preganency indicates that the fetus is a female carrier with one mutation (nt1366C > CT) inherited from the father. The homozygous missence mutation ( nt411T > C, p. Ile136Thr) in the MCFD2 gene accounts for the proband 2 and 3. The daughter of the proband 2 is a carrier with a heterozygous mutation inherited from her mother. The homozygous nonsence mutation in the LMAN1 gene of the proband 4 results in the deficency of F Ⅴ and FⅧ.

Study on the molecular mechanism of the inherited factor X deficiency in three unrelated families / 中华检验医学杂志

Objective To identify the clinical features, the molecular diagnosis and the molecular mechanism of three unrelated factor X deficiency families. Methods Three probands were male and the diagnosis was validated by coagulant parameters. The F X coagulation activity ( F X∶ C ) and antigen (FX∶ Ag) were tested by clotting test and ELISA method. The cross-corrected test was used to rule out the inhibitor of FX in plasma. Thrombin generation test was evaluated. The antigen and the molecule weight of the FX in plasma were measured with western blotting. Gene mutations were analyzed in the probands and their family members with PCR and DNA sequencing. FX expression plasmids were constructed and transientby being transfected into 293T cells. FX: C and FX: Ag of the expression products were tested. Results APTT and PT in proband 1 were obviously prolonged, 113.4 s and 62.3 s, respectively. And there was no inhibitor in plasma. The thrombin generation was lower compared to normal reference. APTT and PT in proband 2 were 56. 5 s and 28.7 s. There was no inhibitor in the plasma. The thrombin generation was 1 101.5 nmol · min. APTT and PT in proband 3 were 117.3 s and 44. 3 s. The thrombin generation was 782.5 nmol · min. FX∶ C and FX∶ Ag in proband 1 were 1.4% and 3.6%, with a homozygous mutation in FX gene (Ser425→Pro). In vitro expression of the mutation showed a normal synthesis in the cell but secretion dysfuntion. In proband 2 F X: C and F X: Ag were 2. 2% and 5. 5%, with two heterozygous mutations in FX gene (Ala-29→Pro and Phe324→Leu). The Ala-29 → Pro mutation led to significantly reduced expressions of FX in both cell lysate and cell culture supernatants compared to wild-type plasmid,(41.32 ±5.21 )% and(6. 30 ± 1.84)% respectively. However Phe324→Leu mutation almost did not affect the FX synthesis. FX: C and FX: Ag in proband 3 were 2. 2% and 35%, with two heterozygous mutations in FX gene( Ala235→Thr and Arg347→Cys). The expressions of these two mutant FX proteins in cell lysate were similar to those of wild-type but obviously lower in the supernatant. Conclusions Five mutations of F X gene are found in this study. These mutations (Ser425Pro, Phe324Leu, Ala235Thr and Arg347Cys)can not affect F X protein synthesis. However Ala-29Pro mutation can reduce F X protein synthesis and cause secretion dysfunction.

Molecular analysis of the genotypes and phenotypes in three pedigrees with inherited antithrombin defidency / 中华检验医学杂志

Objective To investigate the clinical phenotype and genotype in three probands with antithmmbin(AT)deficiency and their families,and to identify the molecular mechanism of AT deficiency.Methods Chromogenic substrate method and immunoturbidimetry assay was used to detect the plasma levels of AT:A and AT:Ag,respectively.Genomic DNA was extracted from the peripheral blood.All 7 exons and the flanking sequences were amplified by PCR.and the abnormal mutant genes were analyzed by direct sequencing.Western blot was used to detect the AT levels and thrombin generation tests were used to detect coagulation status.Results The plasma levels of AT:A and AT:Ag of the three probands declined by 50%.G7386C(Trp225Cys)mutation in exon 4,C2591G(Ser36stop)in exon 2 and C9819T(Arg359stop)in exon 5 were characterized in the three prebands and they could result in W(Trp)225C(Cys)missense mutation,S(Set)36X(stop)nonsense mutation and R(Arg)359X(stop)nonsense mutation respectively,The testing results of phenotype and genotype from some of their family members showed consistent with results from the probands.Western blot results indicated that the Icyels of PC:Ag were lower compared with the normal pooled plasma.The hypercoagulative status was present in the probands using thrombin generation tests.Conclusions Type Ⅰ hereditary AT deficiency was found in these three families.The 3 heterozygous mutations.W225C,S36X and R359X are genetic defects of hereditary AT deficiency.W225C and S36X have not been described before.

Genetic diagnosis of two haemophilia families with recombination / 中华检验医学杂志

objective To make genetic diagnosis in two haemophilia families with recombination. Methods For hemophilia A(HA)family,screening of the F Ⅷ intron 22 and intron 1 inversion mutations was employed to identify the mutation. Linkage analysis with 8 polymorphic markers was adopted in the pedigree. For hemophilia B(HB)family,DNA sequencing of all coding regions of FⅨ gene Was used to detect the mutation directly. The muhifluorescent PCR method employing six FⅨ related STR was adopted in linkage analysis.Results In the HA family,the proband was positive in inversion 1 detection and the relative female was inversion 1 carrier. But linkage analysis with polymorphic markers showed contrary resuhs. Some markers certified that the female inherited the disease chromosome of the family while the others showed contrary results.In the HB family,it was unsuccessful in sequencing the exon 7 of the F Ⅸ gene in the proband and there was no mutation found in the other parts. The relative female and her amniocyte DNA were successful in sequencing the whole F Ⅸ gene and no mutation was detected.The linkage analysis of the family showed contrary results. Recombination occured in these two families. Conclusions Although the linkage analysis iS convenient and effective in carrier and prenatal diagnosis of hemophilia families. The recombination risk shouldn't be neglected especially when the polymorphic markers give inconsistent information for linkage analysis. It is necessary to find some high inforrnative markers intragenic or on the telomeric side to the gene in order to prevent the risk of recombination.

Haemophilia A in a female with a novel INV22 mutation and skewed X-chromosome inactivation / 中华检验医学杂志

0bjective To make genetic and prenatal diagnosis of a female with Haemophilia A.Methotis The FⅧ:C.BT and VWF were detected to make phenotypic diagnosis.LD-PCR was adopted for screening the intron 22 inversion and PCR was adopted for the screening the intron 1 inversion.The coding and boundary sequences of FⅧgene were analyzed by PCR and DNA equencing.Eight combined polymorphie markers(Amelo,F8IVS13,CA22,DXS15,DXS9901,G6PD,DXS1073 and DXS1108)were applied for linkage analysis of the family by multiplex fluorescent PCR.The polymorphism of DXS52 (ST14)was analyzed by PCR and electrophoresis. Assessment of X inactivation was performed using an Hpa II-polymerase chain eaction (PCR)assay for the X-inked human androgen receptor gene(HUMARA). Results The female HA patient showed severe FW deficiency(FⅧ:C 2.1%)and other phenotypie tests were normal.Her family members showed normal in all tests.The female proposita was found to be a carrier of FW gene intron 22 inversion.But her family members as well as her etus showed negative results.Except this inversion,no other mutation Wag found then.The female inherited two X chromosomes from both her parents' and her fetus inherited the maternally derived X chromosome from the female proposita according to the linkage analysis.Furthermore.X-inactivation paRern of the female was unbalanced and her aternally derived X chromosome Wag inaetived mostly while the majority of her paternal derived one kept active.Conclusions The severe haemophilia A in the proposita resulted from the de novo Ⅷ intron 22 inversion which most probably arose in the paternal germ line.Associated with a skewing pattern of inactivation of the maternally derived X chromosome.Her etus is normal female.