Adhesin Antibody-Grafted Mesoporous Silica Nanoparticles Suppress Immune Escape for Treatment of Fungal Systemic Infection.

Life-threatening systemic fungal infections caused by Candida albicans are significant contributors to clinical mortality, particularly among cancer patients and immunosuppressed individuals. The evasion of the immune response facilitated by fungal surface components enables fungal pathogens to evade macrophage attacks and to establish successful infections. This study developed a mesoporous silica nanoplatform, i.e., MSNP-EAP1Ab, which is composed of mesoporous silica nanoparticles grafted with the antibody of C. albicans surface adhesin Eap1. The activity of MSNP-EAP1Ab against C. albicans immune escape and infection was then evaluated by using the cell interaction model and the mouse systemic infection model. During interaction between C. albicans cells and macrophages, MSNP-EAP1Ab significantly inhibited fungal immune escape, leading to the enhanced phagocytosis of fungal cells by macrophages, with phagocytosis rates increasing from less than 8% to 14%. Furthermore, after treatment of the C. albicans-infected mice, MSNP-EAP1Ab drastically prolonged the mouse survival time and decreased the kidney fungal burden from >30,0000 CFU/g kidney to <100 CFU/g kidney, indicating the rapid recognition and killing of the pathogens by immune cells. Moreover, MSNP-EAP1Ab attenuated kidney tissue inflammation, with remarkable attenuation of renal immune cell accumulation. This study presents an innovative nanoplatform that targets the C. albicans adhesin, offering a promising approach for combatting systemic fungal infections.

[Identification of Cervi Cornu (Cervus elaphus) and its formula granules based on PCR-RFLP].

Cervi Cornu is the ossified antler, or the base antler that falls off in the spring of the following year after the pilose antler is sawn off from Cervus elaphus or C. nippon, as a precious traditional Chinese medicine, has been recognized for its medicinal value and widely used in clinical practice. However, the origins of Cervi Cornu are miscellaneous, and Cervi Cornu is even mixed with adulterants in the market. Currently, there is a shortage of ways to identify Cervi Cornu and no standard to control the quality of Cervi Cornu. So it is valuable to develop a way to effectively identify Cervi Cornu from the adulterants. In this study, the differences in the mitochondrial barcode cytochrome b(Cytb) gene sequences of C. elaphus, C. nippon and their related species were compared and the specific single nucleotide polymorphism(SNP) sites on the Cytb sequences of Cervi Cornu were screened out. According to the screened SNPs, Cervi Cornu-specific primers dishmy-F and dishmy-R were designed. The PCR system was established and optimized, and the tolerance and feasibility of Taq polymerases and PCR systems affecting the repeatability of the PCR method were investigated. The amplification products of C. elaphus and C. nippon were digested using the restriction enzyme MseⅠ. The results showed that after electrophoresis of the product from PCR with the annealing temperature of 56 ℃ and 35 cycles, a single specific band at about 100 bp was observed for C. elaphus samples, and the product of C. elaphus samples was 60 bp shorter than that of C. nippon samples. There was no band for adulterants from other similar species such as Alces alces, Rangifer tarandus, Odocoileus virginianus, O. hemionus, Cap-reolus pygargus, Przewalskium albirostis and negative controls. The polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) method established in this study can quickly and accurately identify Cervi Cornu originated from C. elaphus in crude drugs, standard decoctions, and formula granules, and distinguish the origins of Cervi Cornu products, i.e., C. nippon and similar species. This study can be a reference for other studies on the quality standard of other formula granules of traditional Chinese medicines.

Reduction of histone proteins dosages increases CFW sensitivity and attenuates virulence of Candida albicans.

Histone proteins are important components of nucleosomes, which play an important role in regulating the accessibility of DNA and the function of genomes. However, the effect of histone proteins dosages on physiological processes is not clear in the human fungal pathogen Candida albicans. In this study, we found that the deletion of the histone protein H3 coding gene HHT21 and the histone protein H4 coding gene HHF1 resulted in a significant decrease in the expression dosage of the histone proteins H3 and H4, which had a significant impact on the localization of the histone protein H2A and plasmid maintenance. Stress sensitivity experiments showed that the mutants hht21Δ/Δ, hhf1Δ/Δ and hht21Δ/Δhhf1Δ/Δ were more sensitive to cell wall stress induced by Calcofluor White (CFW) than the wild-type strain. Further studies showed that the decrease in the dosage of the histone proteins H3 and H4 led to the change of cell wall components, increased chitin contents, and down-regulated expression of the SAP9, KAR2, and CRH11 genes involved in the cell wall integrity (CWI) pathway. Overexpression of SAP9 could rescue the sensitivity of the mutants to CFW. Moreover, the decrease in the histone protein s dosages affected the FAD-catalyzed oxidation of Ero1 protein, resulting in the obstruction of protein folding in the ER, and thus reduced resistance to CFW. It was also found that CFW induced a large amount of ROS accumulation in the mutants, and the addition of ROS scavengers could restore the growth of the mutants under CFW treatment. In addition, the reduction of the histone proteins dosages greatly weakened systemic infection and kidney fungal burden in mice, and hyphal development was significantly impaired in the mutants under macrophage treatment, indicating that the histone proteins dosages is very important for the virulence of C. albicans. This study revealed that histone proteins dosages play a key role in the cell wall stress response and pathogenicity in C. albicans.