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The phenotype of albino tea plants (ATPs) is significantly influenced by temperature regimes and light conditions, which alter certain components of the tea leaves leading to corresponding phenotypic changes. However, the regulatory mechanism of temperature-dependent changes in photosynthetic pigment contents and the resultant leaf colors remain unclear. Here, we examined the chloroplast microstructure, shoot phenotype, photosynthetic pigment content, and the expression of pigment synthesis-related genes in three tea genotypes with different leaf colors under different temperature conditions. The electron microscopy results revealed that all varieties experienced the most severe chloroplast damage at 15 °C, particularly in albino cultivar Baiye 1 (BY), where chloroplast basal lamellae were loosely arranged, and some chloroplasts were even empty. In contrast, the chloroplast basal lamellae at 35 °C and 25 °C were neatly arranged and well-developed, outperforming those observed at 20 °C and 15 °C. Chlorophyll and carotenoid measurements revealed a significant reduction in chlorophyll content under low temperature treatment, peaking at ambient temperature followed by high temperatures. Interestingly, BY showed remarkable tolerance to high temperatures, maintaining relatively high chlorophyll content, indicating its sensitivity primarily to low temperatures. Furthermore, the trends in gene expression related to chlorophyll and carotenoid metabolism were largely consistent with the pigment content. Correlation analysis identified key genes responsible for temperature-induced changes in these pigments, suggesting that changes in their expression likely contribute to temperature-dependent leaf color variations. [ABSTRACT FROM AUTHOR]

Integrin β4 (ITGB4) is a member of the integrin family, which plays a crucial role in mediating cell adhesion to the extracellular matrix. Recent studies have demonstrated that ITGB4 is involved in tumorigenesis and metastasis during the development of cancer. However, the role of ITGB4 in oral squamous cell carcinoma (OSCC) remains unclear. A Multiplex immunohistochemistry (OPAL™, mIHC) assay was employed to stain ITGB4, ALDH1, PD-L1, cytokeratin (CK), CD8 and PD-1 in a human OSCC tissue microarray, containing 26 normal oral epithelium samples, 21 oral epithelium dysplasia samples and 76 OSCC samples. The expression pattern and clinicopathological characteristics of ITGB4 were analyzed and compared with those of PD-1, PD-L1, ALDH1 and CD8. The correlation between subgroups of tumor cells, including ITGB4+PD-L1+ and ITGB4+ALDH1+, and subgroups of T cells, including CD8+ and CD8+PD-1+, was evaluated using two-tailed Pearson's statistics. A Kaplan–Meier curve was built, and a log-rank test was performed to analyze the survival rate of different subgroups. The mIHC staining results show that ITGB4 was mostly expressed in the tumor cells, with a significant increase in the OSCC specimens compared with normal oral epithelium and oral epithelium dysplasia. The paired analysis, conducted between the OSCC tumor tissue and normal paracancer mucosa, confirmed the results. The study further revealed that ITGB4+PD-L1+ cancer cells, but not ITGB4+ALDH1+ cancer cells, were significantly associated with the infiltration of CD8+ T cells (positivity p = 0.005, positive number p = 0.03). Additionally, ITGB4+PD-L1+ tumor cells were positively correlated with CD8+PD-1+ T cells (positivity p = 0.02, positive number p = 0.03). Most intriguingly, the subgroup of ITGB4/PD-L1high with CD8/PD-1high displayed the best prognosis compared with the other considered subgroups. The results show that the expression of ITGB4 was increased in OSCC compared with normal oral mucosa. Furthermore, a specific subgroup with high levels of expression of ITGB4/PD-L1 and CD8/PD-1 was found to have a relatively better prognosis compared with the other subgroups. Ultimately, this study sheds light on the potential role of ITGB4 in OSCC and provides a basis for further investigation. [ABSTRACT FROM AUTHOR]

Unlike that of other crops, the growth of tea plants can be promoted by aluminum, but its regulation mechanism remains unclear. Some endophytes can also promote growth of plant hosts. In this paper, tea roots treated with aluminum were used to study the growth-promoting traits and aluminum tolerance of endophytes. Meta-16S rDNA analysis revealed that Burkholderia was enriched in tea roots after aluminum treatment, and it was the dominant strain for hydroponic tea roots and field tea roots. Actinomycetes constituted the dominant strains in hydroponic tea seedlings treated with aluminum. Sixteen endophytic bacteria, including 12 strains of Firmicutes , 2 strains of Proteobacteria and 2 strains of Actinomycetes , were isolated and identified from hydroponic tea roots treated with different aluminum concentrations. Growth-promoting activity analysis showed that the isolated endophytic bacteria all had more than one plant growth-promoting trait. Among them, B4 (Bacillus nealsonii), B8 (Brevibacterium frigoritolerans) and A2 (Nocardia nova) bacteria each had three growth-promoting traits. Aluminum tolerance ability analysis indicated that endophyte A1 (Leifsonia shinshuensis) had the strongest aluminum tolerance ability, up to 200 mg l−1 aluminum. Plant–bacteria interactions showed that endophytes A1, A2 and B4 and their synthetic community all had a growth-promoting effect on the growth of wheat lateral roots. Moreover, endophytes A1 and B4 alleviated aluminum stress in wheat. Endophyte A1 also promoted the growth of tea cuttings, especially lateral roots, with/without aluminum. Taken together, aluminum enhanced the distribution of aluminum-tolerant and growth-promoting bacteria, thereby promoting the growth of tea roots. This study provides a new aspect for research on the mechanism by which aluminum promotes tea plant growth. [ABSTRACT FROM AUTHOR]

Background: Cancer immunotherapy offers a promising approach in cancer treatment. The adenosine A2A receptor (A2AR) could protect cancerous tissues from immune clearance via inhibiting T cells response. To date, the role of A2AR in head and neck squamous cell carcinoma (HNSCC) has not been investigated. Here, we sought to explore the expression and immunotherapeutic value of A2AR blockade in HNSCC., Methods: The expression of A2AR was evaluated by immunostaining in 43 normal mucosae, 48 dysplasia and 165 primary HNSCC tissues. The immunotherapeutic value of A2AR blockade was assessed in vivo in genetically defined immunocompetent HNSCC mouse model., Results: Immunostaining of HNSCC tissue samples revealed that increased expression of A2AR on tumor infiltrating immune cells correlated with advanced pathological grade, larger tumor size and positive lymph node status. Elevated A2AR expression was also detected in recurrent HNSCC and HNSCC tissues with induction chemotherapy. The expression of A2AR was found to be significantly correlated with HIF-1α, CD73, CD8 and Foxp3. Furthermore, the increased population of CD4 + Foxp3 + regulatory T cells (Tregs), which partially expressed A2AR, was observed in an immunocompetent mouse model that spontaneously develops HNSCC. Pharmacological blockade of A2AR by SCH58261 delayed the tumor growth in the HNSCC mouse model. Meanwhile, A2AR blockade significantly reduced the population of CD4 + Foxp3 + Tregs and enhanced the anti-tumor response of CD8 + T cells., Conclusions: These results offer a preclinical proof for the administration of A2AR inhibitor on prophylactic experimental therapy of HNSCC and suggest that A2AR blockade can be a potential novel strategy for HNSCC immunotherapy.

B7 Homolog 3 (B7-H3), a newly identified member of the B7 family, is over-expressed in various human cancers and plays a vital role in tumor progression. To identify the expression pattern of B7-H3 in human salivary adenoid cystic carcinoma (AdCC) and its underlying mechanisms, we characterized B7-H3 expression in AdCC tissue microarrays using immunohistochemical staining, and analyzed potentially associated molecules. The results showed that B7-H3 was highly expressed in salivary AdCC, compared with normal salivary glands. Statistical analyses of immunohistochemical staining showed that B7-H3 was closely correlated with Slug and p-STAT3. Functional studies showed that knockdown of B7-H3 in AdCC cell lines using RNA interference did not influence cell growth and apoptosis, but decreased migration and invasion in vitro . Further mechanism studies suggested that B7-H3 influenced the migration and invasion of AdCC cells by regulating the epithelial-mesenchymal transition via JAK2/STAT3 pathway components. Collectively, these findings suggested that B7-H3 may be a potential therapeutic target for AdCC.