FIG. 3. .

Flow cytometric results of intracellular staining for IFN-γ for gated IEL populations for each study group. Cell populations are expressed as the percentage of gated cells with (A) CD8-αα and (B) CD8-αβ subpopulations of CD8+ IEL. As virtually all IFN-γ were detected in CD8+ IEL, CD4 data is not shown. TPN administration led to a significant increase in the expression of IFN-γ, and the supplementation of glutamine led to a marked prevention of this increase. Note that TPN+GLN mice treated with IL-7R-blocking antibody (TPN+GLN+anti-IL-7R) failed to change the suppression in IFN-γ expression with glutamine. *P < 0.05 control vs. TPN; **P < 0.01 TPN+GLN (both groups) vs. control and TPN groups. N = minimum of five per group. Abbreviations: CONT, control; IEL, intraepithelial lymphocyte; IFN, interferon; IL, interleukin; TPN, total parenteral nutrition; TPN+GLN, TPN with glutamine supplementation.