Background: Immunotherapy has revolutionized the therapeutical regimen for nasopharyngeal carcinoma (NPC), yet its response rate remains insufficient. Programmed death‐ligand 1 (PD‐L1) on small extracellular vesicles (sEVs) mediates local and peripheral immunosuppression in tumors, and the mechanism of PD‐L1 loading into these vesicles is garnering increasing attention. Latent membrane protein 1 (LMP1), a key viral oncoprotein expressed in Epstein‐Barr virus (EBV)‐positive NPC, contributes to remodeling the tumor microenvironment. However, the precise mechanisms by which LMP1 modulates tumor immunity in NPC remain unclear. Here, we aimed to investigate the roles and regulatory mechanisms of LMP1 and sEV PD‐L1 in NPC immune evasion. Methods: We analyzed the impact of LMP1 on tumor‐infiltrating lymphocyte abundance in NPC tissues and humanized tumor‐bearing mouse models using multiplex immunofluorescence (mIF) and flow cytometry, respectively. Transmission electron microscopy and nanoparticle tracking analysis were employed to characterize sEVs. Immunoprecipitation‐mass spectrometry was utilized to identify proteins interacting with LMP1. The regulatory effects of sEVs on tumor microenvironment were assessed by monitoring CD8 ⁺ T cell proliferation and interferon‐γ (IFN‐γ) expression via flow cytometry. Furthermore, the expression patterns of LMP1 and downstream regulators in NPC were analyzed using mIF and survival analysis. Results: High LMP1 expression in NPC patient specimens and mouse models was associated with restricted infiltration of CD8 ⁺ T cells. Additionally, LMP1 promoted sEV PD‐L1 secretion, leading to inhibition of CD8 ⁺ T cell viability and IFN‐γ expression in vitro. Mechanistically, LMP1 recruited apoptosis‐linked gene 2‐interacting protein X (ALIX) through its intracellular domain and bound PD‐L1 through its transmembrane domain, thereby facilitating the loading of PD‐L1 into ALIX‐dependent sEVs. Disruption of ALIX diminished LMP1‐induced sEV PD‐L1 secretion and enhanced the anti‐tumor immunity of CD8 ⁺ T cells both in vitro and in vivo. Moreover, increased expression levels of LMP1 and ALIX were positively correlated with enhanced immunosuppressive features and worse prognostic outcomes in NPC patients. Conclusion: Our findings uncovered the mechanism by which LMP1 interacts with ALIX and PD‐L1 to form a trimolecular complex, facilitating PD‐L1 loading into ALIX‐dependent sEV secretion pathway, ultimately inhibiting the anti‐tumor immune response in NPC. This highlights a novel target and prognostic marker for NPC immunotherapy.

Background: Two major ways of macrophage (MΦ) activation can occur in radiation-induced pulmonary injury (RPI): classical and alternative MΦ activation, which play important roles in the pathogenesis of RPI. MΦ can produce chemokine MΦ inflammatory protein-1α (MIP-1α), while MIP-1α can recruit MΦ. The difference in the chemotactic ability of MIP-1α toward distinct activated MΦ is unclear. We speculated that there has been important interaction of MIP-1α with different activated MΦ, which might contribute to the pathogenesis of RPI.Methods: Classically and alternatively activated MΦ were produced by stimulating murine MΦ cell line RAW 264.7 cells with three different stimuli (LPS, IL-4 and IL-13); Then we used recombinant MIP-1α to attract two types of activated MΦ. In addition, we measured the ability of two types of activated MΦ to produce MIP-1α at the protein or mRNA level.Results: Chemotactic ability of recombinant MIP-1α toward IL-13-treated MΦ was the strongest, was moderate for IL-4-treated MΦ, and was weakest for LPS-stimulated MΦ (p < 0.01). The ability of LPS-stimulated MΦ to secrete MIP-1α was significantly stronger than that of IL-4-treated or IL-13-treated MΦ (p < 0.01). The ability of LPS-stimulated MΦ to express MIP-1α mRNA also was stronger than that of IL-4- or IL-13-stimulated MΦ (p < 0.01).Conclusions: The chemotactic ability of MIP-1α toward alternatively activated MΦ (M2) was significantly greater than that for classically activated MΦ (M1). Meanwhile, both at the mRNA and protein level, the capacity of M1 to produce MIP-1α is better than that of M2. Thus, chemokine MIP-1α may play an important role in modulating the transition from radiation pneumonitis to pulmonary fibrosisin vivo, through the different chemotactic affinity for M1 and M2.

Background: Thalassemia is a group of common genetic hematologic disorders characterized by deficient synthesis of the hemoglobin chain. Due to effective blood transfusion and optimization of chelate therapy, the survival of thalassemia patients and their overall quality of life have improved noticeably in the past few decades. As a consequence, the longer life expectancy has led to the manifestation of several concomitant morbidities, including heart disease, infections, cirrhosis, endocrine abnormalities, various malignancies, and so on. In this context, the probability and updated literature about some malignancy cases in patients with thalassemia build new scenarios for the next few years. We describe the first report of a thalassemic patient developing diabetes and head and neck cancer and try to summarize the possible predisposing factors and mechanisms behind their phenomenon.Case presentation: The current case report describes a 50-year-old Asian man who has been diagnosed with thalassemia since childhood. In early 2017, he was also diagnosed with diabetes and started on insulin-hypoglycemic treatment. The patient was then diagnosed with primary non-keratinizing undifferentiated carcinoma of the nasopharynx in late February 2013. A biopsy of the left tongue revealed squamous cell carcinoma (SCC) in late March 2019.Conclusions: We report the first case of a thalassemic patient developing diabetes and squamous cell carcinoma of the head and neck and discuss the possibility of a link between the three diseases. This specific case should alert physicians to the possibility of endocrinopathy and malignancy in thalassemic patients.