Our finding that 0% of parents correctly defined fever is both surprising and unsettling, and it should inform future discussions of fever between parents and clinicians.

Self-reactive T cells that survive the process of positive and negative selection during thymocyte development represent potential effector cells against tumors that express these same self-Ags. We have previously shown that CD8+ T lymphocytes (TCD8) specific for an immunorecessive epitope, designated epitope V, from the SV40 large T Ag (Tag) escape thymic deletion in line SV11 Tag-transgenic mice. In contrast, these mice are tolerant to the three most dominant Tag epitopes. The majority of the residual epitope V-specific TCD8 have a low avidity for the target epitope, but a prime/boost regimen can expand higher avidity clones in vivo. Whether higher avidity TCD8 targeting this epitope are affected by Tag-expressing tumors in the periphery or can be recruited for control of tumor progression remains unknown. In the current study, we determined the fate of naive TCR-transgenic TCD8 specific for Tag epitope V (TCR-V cells) following transfer into SV11 mice bearing advanced-stage choroid plexus tumors. The results indicate that TCR-V cells are rapidly triggered by the endogenous Tag and acquire effector function, but fail to accumulate within the tumors. Primary immunization enhanced TCR-V cell frequency in the periphery and promoted entry into the brain, but a subsequent booster immunization caused a dramatic accumulation of TCR-V T cells within the tumors and inhibited tumor progression. These results indicate that epitope V provides a target for CD8+ T cells against spontaneous tumors in vivo, and suggests that epitopes with similar properties can be harnessed for tumor immunotherapy.

Adoptive cell transfer has been shown to significantly reduce established tumors in both experimental models and cancer patients. Due to the toleragenic nature of cancer, approaches that lead to durable maintenance of functional T cells in tumor-bearing hosts are needed to maximize tumor regression. In this study, we investigated strategies to augment CD8+ T cell (T-CD8)-mediated adoptive immunotherapy of mice bearing advanced-stage autochthonous brain tumors by targeting a weakly immunogenic epitope. We found that immunization enhanced the accumulation of adoptively transferred T-CD8 at the tumor site, but that the timing of immunization was critical for optimal T cell expansion. A more rapid accumulation of T-CD8 was achieved when mice were conditioned with agonist anti-CD40 antibody prior to adoptive transfer due to increased T cell activation against the endogenous tumor antigen. Both approaches led to an increase in the lifespan of SV11 mice due to decreased tumor progression. However, tumor-specific T-CD8 did not persist long-term at the tumor site following administration of either regimen. Importantly, the combination of anti-CD40 conditioning followed by optimally-timed immunization synergistically promoted long-term maintenance of T-CD8 in the brain and dramatically enhanced survival. A second round of combination immunotherapy resulted in a further increase in survival, suggesting long-term tumor sensitivity to CD8+ T cell-based immunotherapy. These results demonstrate that even a weak antigen can be effectively targeted for control of established tumors using a combined adoptive transfer plus immune modulation approach and suggest that similar strategies may translate to clinical practice.

Management of pediatric renal transplant patients involves multifactorial monitoring modalities to ensure allograft survival and prevent opportunistic infection secondary to immunosuppression. An ICFA, which utilizes CD4 T-cell production of ATP to assess immune system status, has been used to monitor transplant recipients and predict susceptibility of patients to rejection or infection. However, the validity of this assay to reflect immune status remains unanswered. In a two-yr retrospective study that included 31 pediatric renal transplant recipients, 42 patient blood samples were analyzed for immune cell function levels, creatinine, WBC (white blood cell) count, immunosuppressive drug levels, and viremia, concurrent with renal biopsy. T-cell ATP production as assessed by ICFA levels did not correlate with allograft rejection or with the presence or absence of viremia. ICFA levels did not correlate with serum creatinine or immunosuppressive drug levels, but did correlate with WBC count. The ICFA is unreliable in its ability to reflect immune system status in pediatric renal transplantation. Further investigation is necessary to develop methods that will accurately predict susceptibility of pediatric renal transplant recipients to allograft rejection and infection.

A 15-Year-Old Girl with Dysphagia, Failure to Thrive 1. Defi ne failure to thrive and review the multiple mechanisms that cause growth failure. 2. Review the pathophysiology of esophageal stricture. 3. Describe the diagnosis and treatment of peptic esophageal stricture, including initial workup, medical and surgical therapy, and prognosis.