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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.

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Related in: MedlinePlus

TGF-β in conjunctiva. A: Actin-corrected RT–PCR in conjunctival tissue of 3- and 10-week-old rats after keratoplasty, normalized to non-grafted eye. Transforming growth factor beta (TGF-β) transcription in the grafted eyes of 3-week-old rats is strongly induced on POD 3 (n=3, *p<0.01). B: Actin-corrected RT–PCR in conjunctival tissue after keratoplasty of the grafted eyes of 3-week-old rats, normalized to grafted eyes of the 10-week-old rats (n=3, *p<0.01).
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f5: TGF-β in conjunctiva. A: Actin-corrected RT–PCR in conjunctival tissue of 3- and 10-week-old rats after keratoplasty, normalized to non-grafted eye. Transforming growth factor beta (TGF-β) transcription in the grafted eyes of 3-week-old rats is strongly induced on POD 3 (n=3, *p<0.01). B: Actin-corrected RT–PCR in conjunctival tissue after keratoplasty of the grafted eyes of 3-week-old rats, normalized to grafted eyes of the 10-week-old rats (n=3, *p<0.01).

Mentions: In unrelated keratoplasties without application of Tregs, the conjunctival samples underwent mRNA analysis on days 3 and 14 and the day of rejection. The baby rats but not adult rats strongly induced conjunctival TGF-β mRNA on day 3 compared to the non-grafted eye (p<0.01, n=3; Figure 5A). Comparing TGF-β mRNA levels in the grafted eyes of the two cohorts, the baby rats revealed 6.6-fold higher levels than in the adult rats on day 3 after keratoplasty (p<0.01, n=3; Figure 5B).


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)

TGF-β in conjunctiva. A: Actin-corrected RT–PCR in conjunctival tissue of 3- and 10-week-old rats after keratoplasty, normalized to non-grafted eye. Transforming growth factor beta (TGF-β) transcription in the grafted eyes of 3-week-old rats is strongly induced on POD 3 (n=3, *p<0.01). B: Actin-corrected RT–PCR in conjunctival tissue after keratoplasty of the grafted eyes of 3-week-old rats, normalized to grafted eyes of the 10-week-old rats (n=3, *p<0.01).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f5: TGF-β in conjunctiva. A: Actin-corrected RT–PCR in conjunctival tissue of 3- and 10-week-old rats after keratoplasty, normalized to non-grafted eye. Transforming growth factor beta (TGF-β) transcription in the grafted eyes of 3-week-old rats is strongly induced on POD 3 (n=3, *p<0.01). B: Actin-corrected RT–PCR in conjunctival tissue after keratoplasty of the grafted eyes of 3-week-old rats, normalized to grafted eyes of the 10-week-old rats (n=3, *p<0.01).
Mentions: In unrelated keratoplasties without application of Tregs, the conjunctival samples underwent mRNA analysis on days 3 and 14 and the day of rejection. The baby rats but not adult rats strongly induced conjunctival TGF-β mRNA on day 3 compared to the non-grafted eye (p<0.01, n=3; Figure 5A). Comparing TGF-β mRNA levels in the grafted eyes of the two cohorts, the baby rats revealed 6.6-fold higher levels than in the adult rats on day 3 after keratoplasty (p<0.01, n=3; Figure 5B).

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