Genetic engineering of murine CD8+ and CD4+ T cells for preclinical adoptive immunotherapy studies

T-cell receptor (TCR) gene therapy enables for the rapid creation of antigen-specific T cells from mice of any strain and represents a valuable tool for preclinical immunotherapy studies. Here, we describe the superiority of γ-retroviral vectors compared with lentiviral vectors for transduction of murine T cells and surprisingly illustrate robust gene-transfer into phenotypically naive/memory-stem cell like (TN/TSCM; CD62L(hi)/CD44(low)) and central memory (TCM; CD62L(hi)/CD44(hi)) CD8+ T cells using murine stem cell-based γ-retroviral vectors (MSGV1). We created MSGV1 vectors for a major histocompatibility complex-class I-restricted TCR specific for the melanocyte-differentiation antigen, glycoprotein 100 (MSGV1-pmel-1), and a major histocompatibility complex-class II-restricted TCR specific for tyrosinase-related protein-1 (MSGV1-TRP-1), and found that robust gene expression required codon optimization of TCR sequences for the pmel-1 TCR. To test for functionality, we adoptively transferred TCR-engineered T cells into mice bearing B16 melanomas and observed delayed growth of established tumors with pmel-1 TCR engineered CD8+ T cells and significant tumor regression with TRP-1 TCR transduced CD4 T cells. We simultaneously created lentiviral vectors encoding the pmel-1 TCR, but found that these vectors mediated low TCR expression in murine T cells, but robust gene expression in other murine and human cell lines. These results indicate that preclinical murine models of adoptive immunotherapies are more practical using γ-retroviral rather than lentiviral vectors.     

Liver resections in metastatic gastric cancer

Background

The 5-year survival of patients receiving standard-of-care chemotherapy for metastatic gastric cancer (MGC) to the liver is <2%. This review examines the published data on liver resections for MGC and analyses the rationale for potentially aggressive surgical management.

Methods

A search of the PubMed and Scopus databases was used to identify studies published in English from 1990 to 2009 that reported on 10 or more patients who underwent liver resections for MGC. All available clinicopathologic data were analysed. In particular, we examined longterm survival and the characteristics of individuals surviving for >5 years.

Results

Nineteen studies reported on 436 patients. Median 5-year survival was 26.5% (range: 0–60%). Overall, 13.4% (48/358) of patients were alive at 5 years and studies with extended follow-up reported that 4.0% (7/174) of patients survived for >10 years. Overall in-hospital mortality was 3.5% (12/340 patients); however, the median mortality rate across the studies was 0%. No prognostic factor was found to be consistently statistically significant across these small studies.

Conclusions

Despite the limitations of any analysis of retrospective data for highly selected groups of patients, it would appear that liver resections combined with systemic therapy for MGC can result in prolonged survival.     

Autoimmune hemolytic anemia and idiopathic thrombocytopenic purpura in pediatric solid organ transplant recipients, report of five cases and review of the literature

Cytopenias are common among pediatric SOT; however, autoimmune cytopenias are infrequently reported. We report five cases of autoimmune cytopenias in pediatric LT patients: two with isolated IgG-mediated AIHA, two with ITP, and one with Evans syndrome (ITP and AIHA). All patients were maintained on tacrolimus as immunosuppression. Viral illness commonly preceded the autoimmune cytopenias. All patients responded well to medical therapy (steroids, intravenous immunoglobulin, and rituximab) and lowering tacrolimus serum level. Prognosis appears to be worse when more than one cell line (e.g., Evans syndrome) is affected, and/or there is no preceding viral illness. A critical literature review of autoimmune cytopenias in children following SOT is conducted. Autoimmune cytopenias are a rarely reported complication of pediatric SOT, but clinicians taking care of pediatric transplant recipients need to be aware of this complication.     

Developmental and disease-related influences on self-management acquisition among pediatric liver transplant recipients

Pediatric LT recipients are vulnerable to disruptions in their healthcare management and transitioning to self-managed care. This study aimed to examine whether age at transplant and indication for transplant (acute vs. chronic liver disease) influence later self-management skills. Sixty-three LT recipients, aged 14 and older (M = 17.68, s.d. = 3.01), were recruited and asked to complete a healthcare management survey, the Developmentally Based Skills Checklist, adapted for transplant patients, listing 22 behaviors that medically ill adolescents should progressively master. While there were no significant differences between those who received an LT owing to an acute disease vs. those who received an LT owing to a chronic disease, the age at which patients received their transplant did yield significant results, although, overall, these findings were attenuated by current age. However, our findings indicated that males transplanted at a younger age struggled with mastery over their healthcare responsibilities relative to males transplanted later and females in both age groups. There are many possible reasons why the experience of transplant at a younger age could negatively affect or derail healthcare transitions. Future research is necessary to further untangle this relationship; yet, it seems as though longer time living with LT may make transition harder for families.