AbstractPurpose: Tumor-associated macrophages (TAMs) are pivotal immune cells within the tumor microenvironment (TME), exhibiting dual roles across various cancer types. Depending on the context, TAMs can either suppress tumor progression and weaken drug sensitivity or facilitate tumor growth and drive therapeutic resistance. This study explores whether targeting TAMs can suppress the progression of head and neck squamous cell carcinoma (HNSCC) and improve the efficacy of chemotherapy. Methods: Bioinformatics analyses were performed to evaluate TAMs infiltration levels in HNSCC tumor tissues and examine their associations with patients’ clinicopathological characteristics and prognosis. Flow cytometry was utilized to measure the expression of key macrophage markers and assess apoptosis following treatment with colony stimulating factor 1 receptor (CSF1R) inhibitors (BLZ945, PLX3397). Additionally, immunohistochemistry was employed to detect CD68 and CD8 expression. In vivo, the antitumor efficacy of CSF1R inhibitors was tested in mouse HNSCC tumor model, both as monotherapy and in combination with cisplatin, to evaluate potential synergistic effects. Results: Bioinformatic analysis identified TAMs as the predominant infiltrating immune cells in the TME of HNSCC, with significantly higher infiltration levels in tumor tissues compared to adjacent non-tumor tissues. High TAMs infiltration was associated with poorer overall survival (OS), disease-free survival (DFS), human papillomavirus (HPV) infection status, and advanced disease staging. The TAMs-related genes prediction model demonstrated high prognostic accuracy. CSF1R is primarily expressed in TAMs, where high CSF1R expression may suppress antigen binding and activation. In vitro experiments showed that CSF1R inhibitors induce TAMs apoptosis, enhance their phagocytic activity, and reduce CD206 expression and IL-10 secretion, thereby diminishing their immunosuppressive function. In vivo experiments revealed that while CSF1R inhibitors alone had limited efficacy in suppressing tumor growth, their combination with cisplatin significantly enhanced therapeutic efficacy, as evidenced by increased CD8+ T cell infiltration within the TME. Conclusion: Regulating TAMs by targeting CSF1R to diminish immunosuppressive functions and enhance anti-tumor immunity represents a promising therapeutic strategy for HNSCC.
The widespread use of plasticizers poses a serious threat to the environment and poultry health. Di-(2-ethylhexyl) phthalate (DEHP) is a commonly used plasticizer that can cause liver damage with prolonged exposure. Oxidative stress is closely associated with DEHP toxicity. Macrophage polarization plays an important role in many physiological and pathological processes and regulates disease development. This study aims to elucidate the mechanism of chronic DEHP exposure leading to chicken liver injury through oxidative stress-induced M1 polarization-necroptosis. In this study, the DEHP exposure model of chicken liver and the single and co-culture model of LMH and HD11 cells were established. With increasing dose and time, DEHP decreased body weight, increased liver coefficient, raised activities of liver function indicators and caused pathological liver damage in chickens. Further studies revealed the increase of reactive oxygen species (ROS) level and malonaldehyde (MDA) content, and the decrease of total antioxidant capacity (T-AOC) level, total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) activities, which led to excessive oxidative stress in the liver. In addition, there was increased infiltration of liver macrophages (CD68), upregulation of M1 polarization indicators (CD86, iNOS, IL-1β, TNF-α) and downregulation of M2 polarization indicators (CD163, Arg-1, IL-10, TGF-β) and appearance of necroptosis (RIPK1, RIPK3, MLKL). The vitro experiments confirmed the addition of N-acetylcysteine (NAC) inhibited M1 polarization and necroptosis. Besides, M1 polarization of HD11 cells promoted necroptosis of LMH cells in the HD11-LMH co-culture system. In brief, ROS-mediated M1 polarization-necroptosis is involved in DEHP-induced liver injury. This study provides a reference for environmental toxicant exposure in livestock and poultry farming.
Ticks secrete immunosuppressant proteins that modulate the host's immune system during blood feeding. Five putative genes encoding similar p36 immunosuppressant proteins from other tick species were cloned by sequencing randomly picked plaques from a complementary DNA library constructed from salivary glands of partially engorged Haemaphysalis qinghaiensis. The genes were designated Hq-p36-1, Hq-p36-2, Hq-p36-3, Hq-p36-4, and Hq-p36-5. By doing a Multiple Em for Motif Elicitation (MEME) tool search, 3 potential common motifs, which coincided with 3 conserved regions, were found among the 8 aligned tick p36 homologs. Antigenicity analysis suggested that most of these homologs might be satisfactory antigen candidates, and 2 common antigenic determinants were predicted from each of the 5 proteins, and they overlapped with 2 common motifs. Four out of the 5 Hq-p36 proteins might share a similar 3-dimensional model with an exposed big loop overlapped by the motif MEME-1 and a conserved antigenic region. The finding of the 5 H. qinghaiensis p36 protein homologs could expand our knowledge of tick immunosuppressant proteins and lay ground for future studies to determine their exact role in tick feeding process.
Tumor-associated macrophages (TAMs) are pivotal immune cells within the tumor microenvironment (TME), exhibiting dual roles across various cancer types. Depending on the context, TAMs can either suppress tumor progression and weaken drug sensitivity or facilitate tumor growth and drive therapeutic resistance. This study explores whether targeting TAMs can suppress the progression of head and neck squamous cell carcinoma (HNSCC) and improve the efficacy of chemotherapy. Bioinformatics analyses were performed to evaluate TAMs infiltration levels in HNSCC tumor tissues and examine their associations with patients' clinicopathological characteristics and prognosis. Flow cytometry was utilized to measure the expression of key macrophage markers and assess apoptosis following treatment with colony stimulating factor 1 receptor (CSF1R) inhibitors (BLZ945, PLX3397). Additionally, immunohistochemistry was employed to detect CD68 and CD8 expression. In vivo, the antitumor efficacy of CSF1R inhibitors was tested in mouse HNSCC tumor model, both as monotherapy and in combination with cisplatin, to evaluate potential synergistic effects. Bioinformatic analysis identified TAMs as the predominant infiltrating immune cells in the TME of HNSCC, with significantly higher infiltration levels in tumor tissues compared to adjacent non-tumor tissues. High TAMs infiltration was associated with poorer overall survival (OS), disease-free survival (DFS), human papillomavirus (HPV) infection status, and advanced disease stages. The TAMs-related genes prediction model demonstrated high prognostic accuracy. CSF1R is primarily expressed in TAMs, where high CSF1R expression may suppress antigen binding and activation. In vitro experiments showed that CSF1R inhibitors induce TAMs apoptosis, enhance their phagocytic activity, and reduce CD206 expression and IL-10 secretion, thereby diminishing their immunosuppressive function. In vivo experiments revealed that while CSF1R inhibitors alone had limited efficacy in suppressing tumor growth, their combination with cisplatin significantly enhanced therapeutic efficacy, as evidenced by increased CD8+ T cells infiltration within the TME. Targeting TAMs via CSF1R inhibition enhances the therapeutic efficacy of cisplatin in HNSCC. These findings suggest that CSF1R inhibitors hold promise as a component of combination therapy for HNSCC.