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Assessment of toxicity and biodistribution of recombinant AAV8 vector-mediated immunomodulatory gene therapy in mice with Pompe disease.

Wang G, Young SP, Bali D, Hutt J, Li S, Benson J, Koeberl DD - Mol Ther Methods Clin Dev (2014)

Bottom Line: The vector genome was sustained in all tissues through 16-week postdosing, except for in blood with a similar tissue tropism between males and females.Administration of the vector alone, or combined with the ERT, was effective in producing significantly increased GAA activity and consequently decreased glycogen accumulation in multiple tissues, and the urine biomarker, Glc4, was significantly reduced.The efficacy of the vector (or with ERT) was better in males than in females, as demonstrated both by the number of tissues showing significantly effective responses and the extent of response in a given tissue.

View Article: PubMed Central - PubMed

Affiliation: Applied Toxicology and Gene Therapy Pharm/Tox Program, Lovelace Respiratory Research Institute , Albuquerque, New Mexico, USA.

ABSTRACT
A preclinical safety study was conducted to evaluate the short- and long-term toxicity of a recombinant adeno-associated virus serotype 8 (AAV2/8) vector that has been developed as an immune-modulatory adjunctive therapy to recombinant human acid α-glucosidase (rhGAA, Myozyme) enzyme replacement treatment (ERT) for patients with Pompe disease (AAV2/8-LSPhGAApA). The AAV2/8-LSPhGAApA vector at 1.6 × 10(13) vector particles/kg, after intravenous injection, did not cause significant short- or long-term toxicity. Recruitment of CD4(+) (but not CD8(+)) lymphocytes to the liver was elevated in the vector-dosed male animals at study day (SD) 15, and in group 8 animals at SD 113, in comparison to their respective control animals. Administration of the vector, either prior to or after the one ERT injection, uniformly prevented the hypersensitivity induced by subsequent ERT in males, but not always in female animals. The vector genome was sustained in all tissues through 16-week postdosing, except for in blood with a similar tissue tropism between males and females. Administration of the vector alone, or combined with the ERT, was effective in producing significantly increased GAA activity and consequently decreased glycogen accumulation in multiple tissues, and the urine biomarker, Glc4, was significantly reduced. The efficacy of the vector (or with ERT) was better in males than in females, as demonstrated both by the number of tissues showing significantly effective responses and the extent of response in a given tissue. Given the lack of toxicity for AAV2/8LSPhGAApA, further consideration of clinical translation is warranted in Pompe disease.

No MeSH data available.


Related in: MedlinePlus

Immunodetection of CD4+ lymphocytes in liver. (a) CD4+ lymphocytes quantified from hepatic sinusoids/space of Disse (SOD) for vehicle-treated mice on day 15 and day 113 (groups 1 and 3). (b) CD8+ lymphocytes in hepatic sinusoids/SOD for control mice. (c) Hepatic triads containing CD4+ lymphocytes quantified from vehicle-treated (group 3) and vector-treated (group 8) mice, (d) CD4+ lymphocytes quantified within positive triads. P values calculated with two-tailed t-test. (e–h) Photomics of CD4-stained sections from male mice, focused on the triad regions. On study day (SD) 15, (e) and (f) are from group 2. On SD 113, (g) and (h) are from group 8. (e) and (g) are ×200, and (f) and (h) are ×600 magnification. Arrows indicate CD4+ lymphocytes. Group number indicated on the horizontal axes. Group: 1, vehicle; 2, vector; 3, vehicle; 8, ERT, vector, ERT ×5. ERT, enzyme replacement treatment.
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fig4: Immunodetection of CD4+ lymphocytes in liver. (a) CD4+ lymphocytes quantified from hepatic sinusoids/space of Disse (SOD) for vehicle-treated mice on day 15 and day 113 (groups 1 and 3). (b) CD8+ lymphocytes in hepatic sinusoids/SOD for control mice. (c) Hepatic triads containing CD4+ lymphocytes quantified from vehicle-treated (group 3) and vector-treated (group 8) mice, (d) CD4+ lymphocytes quantified within positive triads. P values calculated with two-tailed t-test. (e–h) Photomics of CD4-stained sections from male mice, focused on the triad regions. On study day (SD) 15, (e) and (f) are from group 2. On SD 113, (g) and (h) are from group 8. (e) and (g) are ×200, and (f) and (h) are ×600 magnification. Arrows indicate CD4+ lymphocytes. Group number indicated on the horizontal axes. Group: 1, vehicle; 2, vector; 3, vehicle; 8, ERT, vector, ERT ×5. ERT, enzyme replacement treatment.

Mentions: There were significantly greater numbers of CD4+ and CD8+ lymphocytes in the hepatic sinusoids/space of Disse (SOD) in the vehicle-treated control females, in comparison with the control males. This phenomenon was consistently observed both in group 1 (SD 15) and group 3 (SD 113) vehicle-treated animals (Figure 4a,b). Vector administration was associated with increased CD4+ lymphocyte at early and late time points. On SD 15, the vector-treated male animals in group 2 had significantly increased recruitment of CD4+ lymphocytes to hepatic sinusoids/SOD and portal triads in comparison with the vehicle-treated control males group 1 (data not shown), which was also seen for group 8 males on SD 113 (Figure 4c–h). A significantly increased recruitment of CD4+ lymphocytes to hepatic triads was detected in the vector-dosed male animals in comparison with the vehicle control male animals (Figure 4c). However, the number of CD4+ lymphocytes in the foci from vector and vehicle-treated mice were not significantly different (Figure 4d). Vector-treated group 2 males had rare CD4+ lymphocytes on SD 15 (Figure 4e,f), whereas vector-treated group 8 animals had multiple CD4+ lymphocytes detected on SD 113 (Figure 4g,h). The elevation of CD4+ lymphocytes has been previously reported to be associated with induction of immune tolerance to GAA.7 No significant increases in CD4+ lymphocytes were observed in other groups of vector mice, in comparison with control mice. In general, the vector (alone or with ERT) treatment had no significant effect on CD8+ lymphocyte recruitment to the liver, indicating a lack of cytotoxic T cell responses (data not shown).


Assessment of toxicity and biodistribution of recombinant AAV8 vector-mediated immunomodulatory gene therapy in mice with Pompe disease.

Wang G, Young SP, Bali D, Hutt J, Li S, Benson J, Koeberl DD - Mol Ther Methods Clin Dev (2014)

Immunodetection of CD4+ lymphocytes in liver. (a) CD4+ lymphocytes quantified from hepatic sinusoids/space of Disse (SOD) for vehicle-treated mice on day 15 and day 113 (groups 1 and 3). (b) CD8+ lymphocytes in hepatic sinusoids/SOD for control mice. (c) Hepatic triads containing CD4+ lymphocytes quantified from vehicle-treated (group 3) and vector-treated (group 8) mice, (d) CD4+ lymphocytes quantified within positive triads. P values calculated with two-tailed t-test. (e–h) Photomics of CD4-stained sections from male mice, focused on the triad regions. On study day (SD) 15, (e) and (f) are from group 2. On SD 113, (g) and (h) are from group 8. (e) and (g) are ×200, and (f) and (h) are ×600 magnification. Arrows indicate CD4+ lymphocytes. Group number indicated on the horizontal axes. Group: 1, vehicle; 2, vector; 3, vehicle; 8, ERT, vector, ERT ×5. ERT, enzyme replacement treatment.
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Related In: Results  -  Collection

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Show All Figures
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fig4: Immunodetection of CD4+ lymphocytes in liver. (a) CD4+ lymphocytes quantified from hepatic sinusoids/space of Disse (SOD) for vehicle-treated mice on day 15 and day 113 (groups 1 and 3). (b) CD8+ lymphocytes in hepatic sinusoids/SOD for control mice. (c) Hepatic triads containing CD4+ lymphocytes quantified from vehicle-treated (group 3) and vector-treated (group 8) mice, (d) CD4+ lymphocytes quantified within positive triads. P values calculated with two-tailed t-test. (e–h) Photomics of CD4-stained sections from male mice, focused on the triad regions. On study day (SD) 15, (e) and (f) are from group 2. On SD 113, (g) and (h) are from group 8. (e) and (g) are ×200, and (f) and (h) are ×600 magnification. Arrows indicate CD4+ lymphocytes. Group number indicated on the horizontal axes. Group: 1, vehicle; 2, vector; 3, vehicle; 8, ERT, vector, ERT ×5. ERT, enzyme replacement treatment.
Mentions: There were significantly greater numbers of CD4+ and CD8+ lymphocytes in the hepatic sinusoids/space of Disse (SOD) in the vehicle-treated control females, in comparison with the control males. This phenomenon was consistently observed both in group 1 (SD 15) and group 3 (SD 113) vehicle-treated animals (Figure 4a,b). Vector administration was associated with increased CD4+ lymphocyte at early and late time points. On SD 15, the vector-treated male animals in group 2 had significantly increased recruitment of CD4+ lymphocytes to hepatic sinusoids/SOD and portal triads in comparison with the vehicle-treated control males group 1 (data not shown), which was also seen for group 8 males on SD 113 (Figure 4c–h). A significantly increased recruitment of CD4+ lymphocytes to hepatic triads was detected in the vector-dosed male animals in comparison with the vehicle control male animals (Figure 4c). However, the number of CD4+ lymphocytes in the foci from vector and vehicle-treated mice were not significantly different (Figure 4d). Vector-treated group 2 males had rare CD4+ lymphocytes on SD 15 (Figure 4e,f), whereas vector-treated group 8 animals had multiple CD4+ lymphocytes detected on SD 113 (Figure 4g,h). The elevation of CD4+ lymphocytes has been previously reported to be associated with induction of immune tolerance to GAA.7 No significant increases in CD4+ lymphocytes were observed in other groups of vector mice, in comparison with control mice. In general, the vector (alone or with ERT) treatment had no significant effect on CD8+ lymphocyte recruitment to the liver, indicating a lack of cytotoxic T cell responses (data not shown).

Bottom Line: The vector genome was sustained in all tissues through 16-week postdosing, except for in blood with a similar tissue tropism between males and females.Administration of the vector alone, or combined with the ERT, was effective in producing significantly increased GAA activity and consequently decreased glycogen accumulation in multiple tissues, and the urine biomarker, Glc4, was significantly reduced.The efficacy of the vector (or with ERT) was better in males than in females, as demonstrated both by the number of tissues showing significantly effective responses and the extent of response in a given tissue.

View Article: PubMed Central - PubMed

Affiliation: Applied Toxicology and Gene Therapy Pharm/Tox Program, Lovelace Respiratory Research Institute , Albuquerque, New Mexico, USA.

ABSTRACT
A preclinical safety study was conducted to evaluate the short- and long-term toxicity of a recombinant adeno-associated virus serotype 8 (AAV2/8) vector that has been developed as an immune-modulatory adjunctive therapy to recombinant human acid α-glucosidase (rhGAA, Myozyme) enzyme replacement treatment (ERT) for patients with Pompe disease (AAV2/8-LSPhGAApA). The AAV2/8-LSPhGAApA vector at 1.6 × 10(13) vector particles/kg, after intravenous injection, did not cause significant short- or long-term toxicity. Recruitment of CD4(+) (but not CD8(+)) lymphocytes to the liver was elevated in the vector-dosed male animals at study day (SD) 15, and in group 8 animals at SD 113, in comparison to their respective control animals. Administration of the vector, either prior to or after the one ERT injection, uniformly prevented the hypersensitivity induced by subsequent ERT in males, but not always in female animals. The vector genome was sustained in all tissues through 16-week postdosing, except for in blood with a similar tissue tropism between males and females. Administration of the vector alone, or combined with the ERT, was effective in producing significantly increased GAA activity and consequently decreased glycogen accumulation in multiple tissues, and the urine biomarker, Glc4, was significantly reduced. The efficacy of the vector (or with ERT) was better in males than in females, as demonstrated both by the number of tissues showing significantly effective responses and the extent of response in a given tissue. Given the lack of toxicity for AAV2/8LSPhGAApA, further consideration of clinical translation is warranted in Pompe disease.

No MeSH data available.


Related in: MedlinePlus