C57BL/6NCrl (B6) and B6.SJL-PtprcaPepcb/BoyCrCrl (CD45.1) mice were obtained from Charles River (via the National Cancer Institute). BALB/cByJ, B6.129S6-Sh2d1atm1Pls/J (SAP−/−), C57BL/6-Tg(Lck-CIITA)16Spark/J (Plck-CIITA), and B6.129S6-Del(3Cd1d2-Cd1d1)1Sbp/J (CD1d−/−) mice were purchased from the Jackson Laboratories. CD8.4 transgenic mice were kindly provided by Dr. Alfred Singer (NCI/CCR, Bethesda). All animals were maintained under specific pathogen-free conditions at the University of Minnesota. All animals used in this study were 6–10 weeks old at the time of analysis. All experimental procedures were approved by the institutional animal care and use committee at the University of Minnesota (IACUC 1706-34889A and 1709-35136A).