Limits...
Small intestinal intraepithelial TCRγδ+ T lymphocytes are present in the premature intestine but selectively reduced in surgical necrotizing enterocolitis.

Weitkamp JH, Rosen MJ, Zhao Z, Koyama T, Geem D, Denning TL, Rock MT, Moore DJ, Halpern MD, Matta P, Denning PW - PLoS ONE (2014)

Bottom Line: In human preterm infants, the proportion of IEL was reduced by 66% in 11 NEC ileum resections compared to 30 non-NEC controls (p<0.001).While γδ IEL dominated over conventional αβ IEL early in gestation in mice and in humans, γδ IEL were preferential decreased in the ileum of surgical NEC patients compared to non-NEC controls (50% reduction, p<0.05).Loss of IEL in human NEC was associated with downregulation of the Th17 transcription factor retinoic acid-related orphan nuclear hormone receptor C (RORC, p<0.001).

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatrics, Vanderbilt University School of Medicine and Monroe Carell Jr. Children's Hospital at Vanderbilt, Nashville, Tennessee, United States of America.

ABSTRACT

Background: Gastrointestinal barrier immaturity predisposes preterm infants to necrotizing enterocolitis (NEC). Intraepithelial lymphocytes (IEL) bearing the unconventional T cell receptor (TCR) γδ (γδ IEL) maintain intestinal integrity and prevent bacterial translocation in part through production of interleukin (IL) 17.

Objective: We sought to study the development of γδ IEL in the ileum of human infants and examine their role in NEC pathogenesis. We defined the ontogeny of γδ IEL proportions in murine and human intestine and subjected tcrδ-/- mice to experimental gut injury. In addition, we used polychromatic flow cytometry to calculate percentages of viable IEL (defined as CD3+ CD8+ CD103+ lymphocytes) and the fraction of γδ IEL in surgically resected tissue from infants with NEC and gestational age matched non-NEC surgical controls.

Results: In human preterm infants, the proportion of IEL was reduced by 66% in 11 NEC ileum resections compared to 30 non-NEC controls (p<0.001). While γδ IEL dominated over conventional αβ IEL early in gestation in mice and in humans, γδ IEL were preferential decreased in the ileum of surgical NEC patients compared to non-NEC controls (50% reduction, p<0.05). Loss of IEL in human NEC was associated with downregulation of the Th17 transcription factor retinoic acid-related orphan nuclear hormone receptor C (RORC, p<0.001). TCRδ-deficient mice showed increased severity of experimental gut injury (p<0.05) with higher TNFα expression but downregulation of IL17A.

Conclusion: Complimentary mouse and human data suggest a role of γδ IEL in IL17 production and intestinal barrier production early in life. Specific loss of the γδ IEL fraction may contribute to NEC pathogenesis. Nutritional or pharmacological interventions to support γδ IEL maintenance in the developing small intestine could serve as novel strategies for NEC prevention.

Show MeSH

Related in: MedlinePlus

More severe intestinal injury in TCRδ−/− mice was associated with increased TNFα and decreased IL17A gene expression.Gene expression of TNFα and IL17A as measured by quantitative RT-PCR in distal small intestinal sections obtained from dam fed wild type (WT control) or TCRδ−/− (tcrδ−/− control) mice; or wild type (WT PAF/LPS) or TCRδ−/− (tcrδ−/− PAF/LPS) mice subjected to experimental gut injury injury as described. Data are representative of 3 independent experiments with at least 3 mice per condition per experiment (*p<0.05).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4048281&req=5

pone-0099042-g008: More severe intestinal injury in TCRδ−/− mice was associated with increased TNFα and decreased IL17A gene expression.Gene expression of TNFα and IL17A as measured by quantitative RT-PCR in distal small intestinal sections obtained from dam fed wild type (WT control) or TCRδ−/− (tcrδ−/− control) mice; or wild type (WT PAF/LPS) or TCRδ−/− (tcrδ−/− PAF/LPS) mice subjected to experimental gut injury injury as described. Data are representative of 3 independent experiments with at least 3 mice per condition per experiment (*p<0.05).

Mentions: To investigate the role of γδ IEL in mucosal homeostasis and cytokine response, we measured mRNA expression of intestinal TNFα and IL17A in mice lacking γδ IEL and exposed to experimental gut injury as described above. At baseline, there was no difference in the histologic appearance of control dam fed wild type or TCRδ−/− mice (Figure 7A). When subjected to experimental gut injury, TCRδ−/− mice were found to have significantly worse disease scores compared to wild type mice (2.1±0.1 versus 2.5±0.1, p<0.05) (Figure 7B). TCRδ−/− mice also exhibited increased incidence of injury (defined as severity scores >2) when compared to wild-type mice (59% vs. 29%). Similarly, intestinal TNFα and IL17A mRNA expression was low in the steady state. In response to PAF-induced epithelial injury, intestinal mRNA expression of both TNFα and IL17A increased in wild type mice. Interestingly, TCRδ-deficient mice demonstrated significantly reduced expression of IL17A (7-fold versus 22-fold induction in IL17A expression, p<0.05) (Figure 8). These data suggest that epithelial injury may induce TCR γδ T cells to express IL-17 in order to protect the intestinal barrier.


Small intestinal intraepithelial TCRγδ+ T lymphocytes are present in the premature intestine but selectively reduced in surgical necrotizing enterocolitis.

Weitkamp JH, Rosen MJ, Zhao Z, Koyama T, Geem D, Denning TL, Rock MT, Moore DJ, Halpern MD, Matta P, Denning PW - PLoS ONE (2014)

More severe intestinal injury in TCRδ−/− mice was associated with increased TNFα and decreased IL17A gene expression.Gene expression of TNFα and IL17A as measured by quantitative RT-PCR in distal small intestinal sections obtained from dam fed wild type (WT control) or TCRδ−/− (tcrδ−/− control) mice; or wild type (WT PAF/LPS) or TCRδ−/− (tcrδ−/− PAF/LPS) mice subjected to experimental gut injury injury as described. Data are representative of 3 independent experiments with at least 3 mice per condition per experiment (*p<0.05).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4048281&req=5

pone-0099042-g008: More severe intestinal injury in TCRδ−/− mice was associated with increased TNFα and decreased IL17A gene expression.Gene expression of TNFα and IL17A as measured by quantitative RT-PCR in distal small intestinal sections obtained from dam fed wild type (WT control) or TCRδ−/− (tcrδ−/− control) mice; or wild type (WT PAF/LPS) or TCRδ−/− (tcrδ−/− PAF/LPS) mice subjected to experimental gut injury injury as described. Data are representative of 3 independent experiments with at least 3 mice per condition per experiment (*p<0.05).
Mentions: To investigate the role of γδ IEL in mucosal homeostasis and cytokine response, we measured mRNA expression of intestinal TNFα and IL17A in mice lacking γδ IEL and exposed to experimental gut injury as described above. At baseline, there was no difference in the histologic appearance of control dam fed wild type or TCRδ−/− mice (Figure 7A). When subjected to experimental gut injury, TCRδ−/− mice were found to have significantly worse disease scores compared to wild type mice (2.1±0.1 versus 2.5±0.1, p<0.05) (Figure 7B). TCRδ−/− mice also exhibited increased incidence of injury (defined as severity scores >2) when compared to wild-type mice (59% vs. 29%). Similarly, intestinal TNFα and IL17A mRNA expression was low in the steady state. In response to PAF-induced epithelial injury, intestinal mRNA expression of both TNFα and IL17A increased in wild type mice. Interestingly, TCRδ-deficient mice demonstrated significantly reduced expression of IL17A (7-fold versus 22-fold induction in IL17A expression, p<0.05) (Figure 8). These data suggest that epithelial injury may induce TCR γδ T cells to express IL-17 in order to protect the intestinal barrier.

Bottom Line: In human preterm infants, the proportion of IEL was reduced by 66% in 11 NEC ileum resections compared to 30 non-NEC controls (p<0.001).While γδ IEL dominated over conventional αβ IEL early in gestation in mice and in humans, γδ IEL were preferential decreased in the ileum of surgical NEC patients compared to non-NEC controls (50% reduction, p<0.05).Loss of IEL in human NEC was associated with downregulation of the Th17 transcription factor retinoic acid-related orphan nuclear hormone receptor C (RORC, p<0.001).

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatrics, Vanderbilt University School of Medicine and Monroe Carell Jr. Children's Hospital at Vanderbilt, Nashville, Tennessee, United States of America.

ABSTRACT

Background: Gastrointestinal barrier immaturity predisposes preterm infants to necrotizing enterocolitis (NEC). Intraepithelial lymphocytes (IEL) bearing the unconventional T cell receptor (TCR) γδ (γδ IEL) maintain intestinal integrity and prevent bacterial translocation in part through production of interleukin (IL) 17.

Objective: We sought to study the development of γδ IEL in the ileum of human infants and examine their role in NEC pathogenesis. We defined the ontogeny of γδ IEL proportions in murine and human intestine and subjected tcrδ-/- mice to experimental gut injury. In addition, we used polychromatic flow cytometry to calculate percentages of viable IEL (defined as CD3+ CD8+ CD103+ lymphocytes) and the fraction of γδ IEL in surgically resected tissue from infants with NEC and gestational age matched non-NEC surgical controls.

Results: In human preterm infants, the proportion of IEL was reduced by 66% in 11 NEC ileum resections compared to 30 non-NEC controls (p<0.001). While γδ IEL dominated over conventional αβ IEL early in gestation in mice and in humans, γδ IEL were preferential decreased in the ileum of surgical NEC patients compared to non-NEC controls (50% reduction, p<0.05). Loss of IEL in human NEC was associated with downregulation of the Th17 transcription factor retinoic acid-related orphan nuclear hormone receptor C (RORC, p<0.001). TCRδ-deficient mice showed increased severity of experimental gut injury (p<0.05) with higher TNFα expression but downregulation of IL17A.

Conclusion: Complimentary mouse and human data suggest a role of γδ IEL in IL17 production and intestinal barrier production early in life. Specific loss of the γδ IEL fraction may contribute to NEC pathogenesis. Nutritional or pharmacological interventions to support γδ IEL maintenance in the developing small intestine could serve as novel strategies for NEC prevention.

Show MeSH
Related in: MedlinePlus