Limits...
Subconjunctivally applied naïve Tregs support corneal graft survival in baby rats.

Hildebrand A, Jarsch C, Kern Y, Böhringer D, Reinhard T, Schwartzkopff J - Mol. Vis. (2014)

Bottom Line: Corneal transplantation is the most frequent and successful form of tissue transplantation in adults (<10% rejection).No significant delay in rejection was observed when Tregs were applied systemically before keratoplasty.Our data suggest that local application of unprimed regulatory T cells may be a therapeutic strategy for preventing corneal graft rejection in young recipients.

View Article: PubMed Central - PubMed

Affiliation: University Eye Hospital, Killianstrasse 5, 79106 Freiburg, Germany ; Faculty of Biology, Albert-Ludwigs-University Freiburg, Germany.

ABSTRACT

Purpose: Corneal transplantation is the most frequent and successful form of tissue transplantation in adults (<10% rejection). In young children, any corneal opacity should be corrected as early as possible to prevent lifelong visual impairment. However, the corneal graft rejection rate is dramatically increased in infants younger than 12 months of age (up to 85% rejection), and immunosuppressive therapy is particularly challenging in this age group. Regulatory T cells (Tregs) are a well-characterized T cell subpopulation with the potential to prevent autoimmune disorders or transplant rejection. Antigen-specific Tregs were shown to inhibit graft rejection in adult stem cell transplantation. Less is known about the role of naïve Tregs.The purpose of the present study was to elucidate the relevance of naïve Tregs in juvenile corneal transplantation in a baby rat keratoplasty model that reproduces the accelerated rejection in young patients.

Methods: Counts and inhibitory potential of Tregs were studied in spleens of 3- and 10-week-old rats. Unprimed Tregs (CD4+CD25+) were isolated from the spleens of 10-week-old Lewis rats and systemically or subconjunctivally administered in vivo in allogenic keratoplasty in 3- and 10-week-old Lewis recipient rats. In subconjunctival tissue, transcription was analyzed for induction of transforming-growth-factor beta (TGF-β).

Results: In 3-week-old rats, CD4 T cell counts, but not FoxP3 T cell counts were lower than in 10-week-old rats. The Tregs of both age groups had the potential to inhibit T cell activation in vitro. No significant delay in rejection was observed when Tregs were applied systemically before keratoplasty. However, subconjunctival application of Tregs abrogated rejection in 66.7% and 33.3% of the 3- and 10-week-old recipients, respectively. Analysis of the conjunctival tissue revealed a transplantation-induced increase in TGF-β transcription in the 3-week-old rats.

Conclusions: Our data suggest that local application of unprimed regulatory T cells may be a therapeutic strategy for preventing corneal graft rejection in young recipients.

Show MeSH

Related in: MedlinePlus

Graft survival after keratoplasty and i.v. Tregs. 3-week-old recipient rats received allogenic keratoplasty and obtained no additional cells (solid line, n=15) or Tregs intravenously (dotted line, n=4). Without cells, grafts were rejected at a median of POD 9, addition of Tregs into the tail vein resulted in a median rejection of day 11 after keratoplasty. Grafts of syngenic recipients (broken line) were not rejected until POD 29 (n=8).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4279769&req=5

f3: Graft survival after keratoplasty and i.v. Tregs. 3-week-old recipient rats received allogenic keratoplasty and obtained no additional cells (solid line, n=15) or Tregs intravenously (dotted line, n=4). Without cells, grafts were rejected at a median of POD 9, addition of Tregs into the tail vein resulted in a median rejection of day 11 after keratoplasty. Grafts of syngenic recipients (broken line) were not rejected until POD 29 (n=8).

Mentions: To test the inhibitory potential in vivo, the following experiment was conducted. The Tregs were sorted from the spleens of 10-week-old naïve rats using the surface markers CD4 and CD25. About 105 cells in 100 µl PBS were injected intravenously (i.v.) into the tail veins of the 3-week-old syngenic recipients. One day later, keratoplasty was performed, and graft survival was assessed using the standard score. Figure 3 shows that the syngenic grafts were not rejected within the observation period (post-operative day [POD] 29 after keratoplasty), allogenic grafts were all rejected by day 11 (n=15), and allogenic grafts in animals treated with Tregs i.v. were rejected by day 12 (n=4).


Subconjunctivally applied naïve Tregs support corneal graft survival in baby rats.

Hildebrand A, Jarsch C, Kern Y, Böhringer D, Reinhard T, Schwartzkopff J - Mol. Vis. (2014)

Graft survival after keratoplasty and i.v. Tregs. 3-week-old recipient rats received allogenic keratoplasty and obtained no additional cells (solid line, n=15) or Tregs intravenously (dotted line, n=4). Without cells, grafts were rejected at a median of POD 9, addition of Tregs into the tail vein resulted in a median rejection of day 11 after keratoplasty. Grafts of syngenic recipients (broken line) were not rejected until POD 29 (n=8).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4279769&req=5

f3: Graft survival after keratoplasty and i.v. Tregs. 3-week-old recipient rats received allogenic keratoplasty and obtained no additional cells (solid line, n=15) or Tregs intravenously (dotted line, n=4). Without cells, grafts were rejected at a median of POD 9, addition of Tregs into the tail vein resulted in a median rejection of day 11 after keratoplasty. Grafts of syngenic recipients (broken line) were not rejected until POD 29 (n=8).
Mentions: To test the inhibitory potential in vivo, the following experiment was conducted. The Tregs were sorted from the spleens of 10-week-old naïve rats using the surface markers CD4 and CD25. About 105 cells in 100 µl PBS were injected intravenously (i.v.) into the tail veins of the 3-week-old syngenic recipients. One day later, keratoplasty was performed, and graft survival was assessed using the standard score. Figure 3 shows that the syngenic grafts were not rejected within the observation period (post-operative day [POD] 29 after keratoplasty), allogenic grafts were all rejected by day 11 (n=15), and allogenic grafts in animals treated with Tregs i.v. were rejected by day 12 (n=4).

Bottom Line: Corneal transplantation is the most frequent and successful form of tissue transplantation in adults (<10% rejection).No significant delay in rejection was observed when Tregs were applied systemically before keratoplasty.Our data suggest that local application of unprimed regulatory T cells may be a therapeutic strategy for preventing corneal graft rejection in young recipients.

View Article: PubMed Central - PubMed

Affiliation: University Eye Hospital, Killianstrasse 5, 79106 Freiburg, Germany ; Faculty of Biology, Albert-Ludwigs-University Freiburg, Germany.

ABSTRACT

Purpose: Corneal transplantation is the most frequent and successful form of tissue transplantation in adults (<10% rejection). In young children, any corneal opacity should be corrected as early as possible to prevent lifelong visual impairment. However, the corneal graft rejection rate is dramatically increased in infants younger than 12 months of age (up to 85% rejection), and immunosuppressive therapy is particularly challenging in this age group. Regulatory T cells (Tregs) are a well-characterized T cell subpopulation with the potential to prevent autoimmune disorders or transplant rejection. Antigen-specific Tregs were shown to inhibit graft rejection in adult stem cell transplantation. Less is known about the role of naïve Tregs.The purpose of the present study was to elucidate the relevance of naïve Tregs in juvenile corneal transplantation in a baby rat keratoplasty model that reproduces the accelerated rejection in young patients.

Methods: Counts and inhibitory potential of Tregs were studied in spleens of 3- and 10-week-old rats. Unprimed Tregs (CD4+CD25+) were isolated from the spleens of 10-week-old Lewis rats and systemically or subconjunctivally administered in vivo in allogenic keratoplasty in 3- and 10-week-old Lewis recipient rats. In subconjunctival tissue, transcription was analyzed for induction of transforming-growth-factor beta (TGF-β).

Results: In 3-week-old rats, CD4 T cell counts, but not FoxP3 T cell counts were lower than in 10-week-old rats. The Tregs of both age groups had the potential to inhibit T cell activation in vitro. No significant delay in rejection was observed when Tregs were applied systemically before keratoplasty. However, subconjunctival application of Tregs abrogated rejection in 66.7% and 33.3% of the 3- and 10-week-old recipients, respectively. Analysis of the conjunctival tissue revealed a transplantation-induced increase in TGF-β transcription in the 3-week-old rats.

Conclusions: Our data suggest that local application of unprimed regulatory T cells may be a therapeutic strategy for preventing corneal graft rejection in young recipients.

Show MeSH
Related in: MedlinePlus