| First Author | Lykens JE | Year | 2011 |
| Journal | Blood | Volume | 118 |
| Issue | 3 | Pages | 618-26 |
| PubMed ID | 21606480 | Mgi Jnum | J:174873 |
| Mgi Id | MGI:5141358 | Doi | 10.1182/blood-2010-12-324533 |
| Citation | Lykens JE, et al. (2011) Perforin is a critical physiologic regulator of T-cell activation. Blood 118(3):618-26 |
| abstractText | Individuals with impaired perforin-dependent cytotoxic function (Ctx(-)) develop a fatal inflammatory disorder called hemophagocytic lymphohistiocytosis (HLH). It has been hypothesized that immune hyperactivation during HLH is caused by heightened infection, defective apoptosis/responsiveness of Ctx(-) lymphocytes, or enhanced antigen presentation. Whereas clinical and experimental data suggest that increased T-cell activation drives HLH, potential abnormalities of T-cell activation have not been well characterized in Ctx(-) hosts. To define such abnormalities and to test these hypotheses, we assessed in vivo T-cell activation kinetics and viral loads after lymphocytic choriomeningitis virus (LCMV) infection of Ctx(-) mice. We found that increased T-cell activation occurred early during infection of Ctx(-) mice, while they had viral burdens that were identical to those of WT animals, demonstrating that T-cell hyperactivation was independent of viral load. Furthermore, cell transfer and signaling studies indicated that increased antigenic stimulation, not a cell-intrinsic defect of responsiveness, underlay heightened T-cell activation in vivo. Finally, direct measurement of viral antigen presentation demonstrated an increase in Ctx(-) mice that was proportional to abnormal T-cell activation. We conclude that perforin-dependent cytotoxicity has an immunoregulatory role that is distinguishable from its pathogen clearance function and limits T-cell activation in the physiologic context by suppressing antigen presentation. |
