Total CD3 T Cells Are Necessary and Sufficient to Induce Colitis in Immunodeficient Mice With Dendritic Cell-Specific Deletion of TGFbR2: A Novel IBD Model to Study CD4 and CD8 T-Cell Interaction.

BACKGROUND: Inflammatory bowel disease (IBD) is a multifactorial disorder, with the innate and adaptive immune cells contributing to disease initiation and progression. However, the intricate cross-talk between immune cell lineages remains incompletely understood. The role of CD8+ T cells in IBD pathogenesis has been understudied, largely due to the lack of appropriate models. METHODS: We previously reported spontaneous colitis in mice with impaired TGFß signaling due to dendritic cell-specific knockout of TGFbR2 (TGFßR2ΔDC). Here, we demonstrate that crossing TGFßR2ΔDC mice with a Rag1-/- background eliminates all symptoms of colitis and that adoptive transfer of unfractionated CD3+ splenocytes is sufficient to induce progressive colitis in Rag1-/-TGFßR2ΔDC mice. RESULTS: Both CD4+ and CD8+ T cells are required for the induction of colitis accompanied by activation of both T-cell lineages and DCs, increased expression of mucosal IFNγ, TNFα, IL6, IL1ß, and IL12, and decreased frequencies of CD4+FoxP3+ regulatory T cells. Development of colitis required CD40L expression in CD4+ T cells, and the disease was partially ameliorated by IFNγ neutralization. CONCLUSIONS: This novel model provides an important tool for studying IBD pathogenesis, in particular the complex interactions among innate and adaptive immune cells in a controlled fashion, and represents a valuable tool for preclinical evaluation of novel therapeutics.

Delta-like Protein 3 Prevalence in Small Cell Lung Cancer and DLL3 (SP347) Assay Characteristics.

CONTEXT.­: Delta-like protein 3 (DLL3) is a protein that is implicated in the Notch pathway. OBJECTIVE.­: To present data on DLL3 prevalence in small cell lung cancer and staining characteristics of the VENTANA DLL3 (SP347) Assay. In addition, the assay's immunoreactivity with other neoplastic and nonneoplastic tissues is outlined. DESIGN.­: Individual formalin-fixed, paraffin-embedded specimens of small cell lung cancer and tissue microarrays comprising neoplastic and nonneoplastic tissues were procured. Sections were cut and stained with DLL3 (SP347) assay. The slides were examined to determine prevalence, staining characteristics, and immunoreactivity. RESULTS.­: Cytoplasmic and/or membranous staining was observed in 1040 of 1362 specimens of small cell lung cancer (76.4%). Homogenous and/or heterogeneous and partial and/or circumferential granular staining with varied intensities was noted. Immunoreactivity was also observed in other neoplastic and nonneoplastic tissues. CONCLUSIONS.­: Our study findings provided the profile of DLL3 staining characteristics that can be used for determining the level of DLL3 expression in small cell lung cancer.