The predominance of a naive T helper cell subset in the immune response of experimental acute pancreatitis.

INTRODUCTION

In necrotizing acute pancreatitis (NAP), systemic inflammatory response syndrome (SIRS) and the compensatory anti-inflammatory response syndrome (CARS) decide overall outcome and mortality. In patients, low lymphocyte counts were found, but T-helper cells seemed to conversely increase. Our aim was to further categorize T-helper cells within the context of NAP induced SIRS and CARS.

METHODS

NAP was induced by injection of sodium-taurocholate into the common bile duct of male BALB/c mice; sham treated animals received saline infusion. The animals were sacrificed at 6, 12, 24 and 48 h later. Lymphocytes from blood, liver and spleen were isolated and examined by flow cytometry. Staining was performed for CD4, CD8, CD19, CD45RB, CD25, CD69, and CD152. CD4 cells were sorted for their CD45RB expression and sought for gene regulation associated to T/T cells by quantitative RT-PCR.

RESULTS

In NAP, CD4 was solely increased in all compartments. CD8 remained without substantial alterations. CD45RB showed significant expression in RB in T-helper cells, confirmed by the CD45RB ratio (Liver, 24 h: NAP 2.2, SHAM 0.6; p < 0.001). CD45RB and cells were not associated to patterns of T/T expression. In NAP, CCR4 expression was significantly decreased within RB cells (fold change: 0.04, p < 0.05), while TLR6 showed significant overexpression (fold change: 2.36, p < 0.05).

CONCLUSION

T-helper cells increase in NAP, leaning towards CD45RB expression. They resemble naive T-cells, in which NAP leads to expression profiles associated with an innate immune response. This suggests new findings in immunological pathomechanisms of NAP.