Platelet-derived extracellular vesicles were engineered for targeted delivery of anti-inflammation therapeutics to treat pneumonia. This delivery strategy improved therapeutic efficacy, inhibited the pulmonary inflammatory cell infiltration, and calmed local cytokine storm syndromes compared with the free drug-treated group.

IL-4 induces Akt activation in macrophages, required for full M2 (alternative) polarization. We examined the roles of Gαi1 and Gαi3 in M2 polarization using multiple genetic methods. Methods and Results: In MEFs and primary murine BMDMs, Gαi1/3 shRNA, knockout or dominant negative mutations attenuated IL-4-induced IL4Rα endocytosis, Gab1 recruitment as well as Akt activation, leaving STAT6 signaling unaffected. Following IL-4 stimulation, Gαi1/3 proteins associated with the intracellular domain of IL-4Rα and the APPL1 adaptor, to mediate IL-4Rα endosomal traffic and Gab1-Akt activation in BMDMs. In contrast, gene silencing of Gαi1/3 with shRNA or knockout resulted in BMDMs that were refractory to IL-4-induced M2 polarization. Conversely, Gαi1/3-overexpressed BMDMs displayed preferred M2 response with IL-4 stimulation. In primary human macrophages IL-4-induced Akt activation and Th2 genes expression were inhibited with Gαi1/3 silencing, but augmented with Gαi1/3 overexpression. In Gαi1/3 double knockout (DKO) mice, M2 polarization, by injection of IL-4 complex or chitin, was potently inhibited. Moreover, in a murine model of asthma, ovalbumin-induced airway inflammation and hyperresponsiveness were largely impaired in Gαi1/3 DKO mice. Conclusion: These findings highlight novel and essential roles for Gαi1/3 in regulating IL-4-induced signaling, macrophage M2 polarization and allergic asthma response.

Numerous reports have elucidated the important participation of exosomes in the communication between tumor cells and other cancer‐related cells including tumor‐associated macrophages (TAMs) in microenvironment. However, the interchange of exosomes between tumor cells and TAMs in the progression of lung adenocarcinoma (LUAD) remains largely enigmatic. Herein, we discovered that LUAD cells induced the M2 polarization of TAMs and the M2‐polarized macrophages facilitated LUAD cell invasion and migration and tumor metastasis in vivo. In detail, LUAD cells secreted exosomes to transport miR‐19b‐3p into TAMs so that miR‐19b‐3p targeted PTPRD and inhibited the PTPRD‐mediated dephosphorylation of STAT3 in TAMs, leading to STAT3 activation and M2 polarization. Also, the activated STAT3 transcriptionally induced LINC00273 in M2 macrophages and exosomal LINC00273 was transferred into LUAD cells. In LUAD cells, LINC00273 recruited NEDD4 to facilitate LATS2 ubiquitination and degradation, so that the Hippo pathway was inactivated and YAP induced the transcription of RBMX. RBMX bound to miR‐19b‐3p to facilitate the packaging of miR‐19b‐3p into LUAD cell‐derived exosomes. Collectively, our results revealed the mechanism underlying the interactive communication between LUAD cells and TAMs through elucidating the exchange of exosomal miR‐19b‐3p and LINC00273 and proved the prometastatic effect of the interchange between two cells. These discoveries opened a new vision for developing LUAD treatment.

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Microbe-based cancer immunotherapy has recently emerged as a hot topic for cancer treatment. However, serious limitations remain including infection associated side-effect and unsatisfactory outcomes in clinic trials. Here, we fabricate different sizes of nano-formulations derived from yeast cell wall (YCW NPs) by differential centrifugation. The induction of anticancer immunity of our formulations appears to inversely correlate with their size due to the ability to accumulate in tumor-draining lymph node (TDLN). Moreover, we use a percolation model to explain their distribution behavior toward TDLN. The abundance and functional orientation of each effector component are significantly improved not only in the microenvironment in tumor but also in the TDLN following small size YCW NPs treatment. In combination with programmed death-ligand 1 (PD-L1) blockade, we demonstrate anticancer efficiency in melanoma-challenged mice. We delineate potential strategy to target immunosuppressive microenvironment by microbe-based nanoparticles and highlight the role of size effect in microbe-based immune therapeutics.

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The chronic inflammatory microenvironment is characterized by the elevated level of reactive oxygen species (ROS). Here, it is hypothesized that developing an ROS‐scavenging scaffold loaded with rapamycin (Rapa@Gel) may offer a new strategy for modulating the local inflammatory microenvironment to improve intervertebral disk tissue regeneration. The therapeutic scaffold consisting of ROS‐degradable hydrogel can be injected into the injured degeneration site of intervertebral disk (IVD) and can release therapeutics in a programmed manner. The ROS scavenged by scaffold reduces the inflammatory responses. It is found that when rats are treated with Rapa@Gel, this results in an increase in the percentage of M2‐like macrophages and a decrease in M1‐like macrophages in the inflammatory environment, respectively. Regeneration of IVD is achieved by Rapa@Gel local treatment, due to the increased M2 macrophages and reduced inflammation. This strategy may be extended to the treatment of many other inflammatory diseases.

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