Project Grant R01HL181432

The National Heart, Lung, and Blood Institute awarded Boston University a Project Grant of $1,605,354 on September 1, 2026, under the Cardiovascular Diseases Research program (CFDA 93.837) to investigate lung interstitial macrophages and their role in bacterial pneumonia defense.

The research examines two major subsets of lung interstitial macrophages—CD206+ and CD206—that occupy distinct anatomic niches and perform different immune functions. Preliminary findings indicate that both subsets respond to pneumococcal pneumonia but with different outcomes: CD206+ interstitial macrophages exhibit enhanced phagocytic capacity against multiple unrelated bacteria in recovered lungs and become significantly more antibacterial following prior infection. The project hypothesizes that lung interstitial macrophages contribute antibacterial defense to lungs experienced with prior pneumonia through mechanisms bolstered by recovery from respiratory infections. Aim 1 tests this hypothesis by selectively depleting CD206+ interstitial macrophages or all interstitial macrophages in naive or pneumococcal-recovered mice to define how these cells influence integrated innate and adaptive immune responses to heterotypic infection and determine whether each subset activates distinct CD4+ T cell types. Aim 2 tests whether interstitial macrophages respond differentially to bacteria in experienced versus naive lungs.

The recipient is the Trustees of Boston University, doing business as Boston University Medical Campus, located in Roxbury, Massachusetts. The award period runs through May 31, 2028. This is a Project Grant, a form of research assistance funding.