Complement C3d enables cell-mediated immunity capable of distinguishing spontaneously transformed from nontransformed cells.

Immune surveillance depends in part on the recognition of peptide variants by T cell antigen receptors. Given that both normal B cells and malignant B cells accumulate mutations we chose a murine model of multiple myeloma to test conditions to induce cell-mediated immunity targeting malignant plasma cell (PC) clones but sparing of normal PCs. Revealing a previously unknown function for intracellular C3d, we found that C3d engaged T cell responses against malignant PC in the bone marrow of mice that had developed multiple myeloma spontaneously.

The effects of age and sex on reference intervals for cobalamin, homocysteine, and serum and urinary methylmalonic acid in healthy adult dogs.

Background: In dogs, data on reference intervals (RIs) for cobalamin, markers of metabolism (markersBmet), age and sex effects are limited.

Hypothesis/objectives: Establish RI for serum cobalamin, homocysteine, and methylmalonic acid (sMMA) concentrations, urinary methylmalonic acid-to-creatinine ratio (uMMA:crea), and determine effects of sex and age.

Methods: Prospective study using healthy dogs (1-10 years).

An injury-induced mesenchymal-epithelial cell niche coordinates regenerative responses in the lung.

Severe lung injury causes airway basal stem cells to migrate and outcompete alveolar stem cells, resulting in dysplastic repair. We found that this "stem cell collision" generates an injury-induced tissue niche containing keratin 5 epithelial cells and plastic Pdgfra mesenchymal cells. Single-cell analysis revealed that the injury-induced niche is governed by mesenchymal proliferation and Notch signaling, which suppressed Wnt/Fgf signaling in the injured niche.