Therapeutic targeting of tumor-associated macrophages.

Tumor-associated macrophages are among the most abundant non-cancerous cells in the tumor microenvironment and in many cancers macrophage infiltration into the tumor is associated with poor prognosis. Macrophages contribute to tumor development by promoting angiogenesis and immune suppression, and display remarkable phenotypic heterogeneity in the tumor microenvironment. Therapeutic strategies targeting macrophages that currently are in clinical development are mainly focused on a general depletion of tumor-associated macrophages, either by targeting the CSF-1/CSF-1R axis or by inhibiting macrophage recruitment by blocking CCR2/CCL2 signaling.

Cardiac regeneration in the axolotl is unaffected by alterations in leukocyte numbers induced by lipopolysaccharide and prednisolone.

Objective: Cardiac regeneration in the axolotl has been found to rely on the innate immune system, and especially macrophages have been demonstrated to play a vital role in regulating the regenerative process. In this study we wanted to induce a pro- and anti-inflammatory milieu in the axolotl during heart regeneration to test the resilience of the regenerative response.

Results: This was induced via repeated intrapericardial injections of lipopolysaccharide or prednisolone during a 40-day regeneration period in order to challenge the presumably fine-tuned inflammatory response that normally facilitates regeneration.