Objective To explore the strategies which reduce the amount of xenoantigen Galα1, 3 Gal. Methods Human α-galactosidase gene and α1,2-fucosyltransferase gene were transferred into cul-tured porcine vascular endothel...Objective To explore the strategies which reduce the amount of xenoantigen Galα1, 3 Gal. Methods Human α-galactosidase gene and α1,2-fucosyltransferase gene were transferred into cul-tured porcine vascular endothelial cells PEDSV.15 and human α-galactosidase transgenic mice were produced. The Galα1,3Gal on the cell surface and susceptibility of cells to human antibody-mediated lysis were analyzed. Results Human α-galactosidase gene alone reduced 78% of Galα1,3Gal on PEDSV.15 cell surface while human α-galactosidase combined with α1,2-fucosyltransferase genes removed Galα1,3Gal completely. Decrease of Galα1,3Gal could reduce susceptibility of cells to human antibody-mediated lysis, especially during co-expression of α-galactosidase gene and α1,2-fucosyltransferase gene. RT-PCR indicated positive human α-galactosidase gene expression in all organs of positive human α-galacto-sidase transgenic F1 mice including heart, liver, kidney, lung, and spleen, the amount of Galα1,3Gal antigens on which was reduced largely. 58% of spleen cells from F1 mice were destroyed by comp-lement-mediated lysis compared with 24% of those from normal mice. Conclusions Human α-galactosidase gene and α1,2-fucosyltransferase gene effectively reduce the expression of Galα1,3Gal antigens on endothelial cell surface and confers resistance to human serum-mediated cytolysis. The expression of human α-galactosidase in mice can also eliminate the Galα1,3Gal antigens in most tissues and decrease the susceptibility of spleen cells to human serum-mediated cytolysis.展开更多
It has been accepted that bone marrow transplantation （BMT） is the only curative therapeutic option for certain hematologic malignancies. The southeast Asia region is an endemic area of hepatitis B virus （HBV） inf...It has been accepted that bone marrow transplantation （BMT） is the only curative therapeutic option for certain hematologic malignancies. The southeast Asia region is an endemic area of hepatitis B virus （HBV） infection; thus, BMT using a hepatitis B surface antigen （HBsAg）- positive donor is occasionally unavoidable. Organ transplantation using a HBsAg-positive donor can lead to post-transplantation de novo HBV infection and severe HBV-related hepatitis if no effective prophylactic measures are taken prior to and after transplantation. In this report, a four-level approach was designed for a patient with chronic myeloid leukemia, beginning with a booster HBV vaccination before performing BMT with a HBsAg-positive donor. Prior to BMT, the HBV viral load of the donor was reduced to an undetectable level by anUviral therapy. After BMT, hepatitis B immunoglobulin was administered intramuscularly for 1 wk together with a long-term antiviral drug, lamivudine. One year after discontinuation of lamivudine, the patient is still free of HBV infection.展开更多
Prophylactic strategies against hepatitis B virus(HBV) recurrence after liver transplantation(LT) are essential for patients with HBV-related disease.Before LT, lamivudine(LAM) was proposed to be down-graded from firs...Prophylactic strategies against hepatitis B virus(HBV) recurrence after liver transplantation(LT) are essential for patients with HBV-related disease.Before LT, lamivudine(LAM) was proposed to be down-graded from first-to second-line therapy.In contrast, adefovir dipivoxil(ADV) has been approved not only as first-line therapy but also as rescue therapy for patients with LAM resistance.Furthermore, combination of ADV and LAM may result in lower risk of ADV resistance than ADV monotherapy.Other new drugs such as entecavir, telbivudine and tenofovir, are probably candidates for the treatment of hepatitis-B-surface-antigen-positive patients awaiting LT.After LT, low-dose intramuscular hepatitis B immunoglobulin(HBIG), in combination with LAM, has been regarded as the most cost-effective regimen for the prevention of post-transplant HBV recurrence in recipients without pretransplant LAM resistance and rapidly accepted in many transplant centers.With the introduction of new antiviral drugs, new hepatitis B vaccine and its new adjuvants, post-transplant HBIG-free therapeutic regimens with new oral antiviral drug combinations or active HBV vaccination combined with adjuvants will be promising, particularly in those patients with low risk of HBV recurrence.展开更多
文摘Objective To explore the strategies which reduce the amount of xenoantigen Galα1, 3 Gal. Methods Human α-galactosidase gene and α1,2-fucosyltransferase gene were transferred into cul-tured porcine vascular endothelial cells PEDSV.15 and human α-galactosidase transgenic mice were produced. The Galα1,3Gal on the cell surface and susceptibility of cells to human antibody-mediated lysis were analyzed. Results Human α-galactosidase gene alone reduced 78% of Galα1,3Gal on PEDSV.15 cell surface while human α-galactosidase combined with α1,2-fucosyltransferase genes removed Galα1,3Gal completely. Decrease of Galα1,3Gal could reduce susceptibility of cells to human antibody-mediated lysis, especially during co-expression of α-galactosidase gene and α1,2-fucosyltransferase gene. RT-PCR indicated positive human α-galactosidase gene expression in all organs of positive human α-galacto-sidase transgenic F1 mice including heart, liver, kidney, lung, and spleen, the amount of Galα1,3Gal antigens on which was reduced largely. 58% of spleen cells from F1 mice were destroyed by comp-lement-mediated lysis compared with 24% of those from normal mice. Conclusions Human α-galactosidase gene and α1,2-fucosyltransferase gene effectively reduce the expression of Galα1,3Gal antigens on endothelial cell surface and confers resistance to human serum-mediated cytolysis. The expression of human α-galactosidase in mice can also eliminate the Galα1,3Gal antigens in most tissues and decrease the susceptibility of spleen cells to human serum-mediated cytolysis.
文摘It has been accepted that bone marrow transplantation （BMT） is the only curative therapeutic option for certain hematologic malignancies. The southeast Asia region is an endemic area of hepatitis B virus （HBV） infection; thus, BMT using a hepatitis B surface antigen （HBsAg）- positive donor is occasionally unavoidable. Organ transplantation using a HBsAg-positive donor can lead to post-transplantation de novo HBV infection and severe HBV-related hepatitis if no effective prophylactic measures are taken prior to and after transplantation. In this report, a four-level approach was designed for a patient with chronic myeloid leukemia, beginning with a booster HBV vaccination before performing BMT with a HBsAg-positive donor. Prior to BMT, the HBV viral load of the donor was reduced to an undetectable level by anUviral therapy. After BMT, hepatitis B immunoglobulin was administered intramuscularly for 1 wk together with a long-term antiviral drug, lamivudine. One year after discontinuation of lamivudine, the patient is still free of HBV infection.
文摘Prophylactic strategies against hepatitis B virus(HBV) recurrence after liver transplantation(LT) are essential for patients with HBV-related disease.Before LT, lamivudine(LAM) was proposed to be down-graded from first-to second-line therapy.In contrast, adefovir dipivoxil(ADV) has been approved not only as first-line therapy but also as rescue therapy for patients with LAM resistance.Furthermore, combination of ADV and LAM may result in lower risk of ADV resistance than ADV monotherapy.Other new drugs such as entecavir, telbivudine and tenofovir, are probably candidates for the treatment of hepatitis-B-surface-antigen-positive patients awaiting LT.After LT, low-dose intramuscular hepatitis B immunoglobulin(HBIG), in combination with LAM, has been regarded as the most cost-effective regimen for the prevention of post-transplant HBV recurrence in recipients without pretransplant LAM resistance and rapidly accepted in many transplant centers.With the introduction of new antiviral drugs, new hepatitis B vaccine and its new adjuvants, post-transplant HBIG-free therapeutic regimens with new oral antiviral drug combinations or active HBV vaccination combined with adjuvants will be promising, particularly in those patients with low risk of HBV recurrence.
