Objective:Candida albicans is a common fungal pathogen that triggers complex host defense mechanisms,including coordinated innate and adaptive immune responses,to neutralize invading fungi effectively.Exploring the im...Objective:Candida albicans is a common fungal pathogen that triggers complex host defense mechanisms,including coordinated innate and adaptive immune responses,to neutralize invading fungi effectively.Exploring the immune microenvironment has the potential to inform the development of therapeutic strategies for fungal infections.Methods:The study analyzed individual immune cell profiles in peripheral blood mononuclear cells from Candida albicans-infected mice and healthy control mice using single-cell transcriptomics,fluorescence quantitative PCR,and Western blotting.We investigated intergroup differences in the dynamics of immune cell subpopulation infiltration,pathway enrichment,and differentiation during Candida albicans infection.Results:Our findings indicate that infiltration of CD4^(+)naive cells,regulatory T(Treg)cells,and Microtubules(MT)-associated cells increased after infection,along with impaired T cell activity.Notably,CD4^(+) T cells and plasma cells were enhanced after infection,suggesting that antibody production is dependent on T cells.In addition,we screened 6 hub genes,transcription factor forkhead box protein 3(Foxp3),cytotoxic T-lymphocyte associated protein 4(CTLA4),Interleukin 2 Receptor Subunit Beta(Il2rb),Cd28,C-C Motif Chemokine Ligand 5(Ccl5),and Cd27 for alterations associated with CD4^(+) T cell differentiation.Conclusions:These results provide a comprehensive immunological landscape of the mechanisms of Candida albicans infection and greatly advance our understanding of adaptive immunity in fungal infections.展开更多
The morphological switch between yeast and hyphae of Candida albicans is essential for its interaction with the host defense system.However,the lack of understanding of host-pathogen interactions during C.albicans inf...The morphological switch between yeast and hyphae of Candida albicans is essential for its interaction with the host defense system.However,the lack of understanding of host-pathogen interactions during C.albicans infection greatly hampers the development of effective immunotherapies.Here,we found that priming with the C.albicans FLO8-deficient(flo8)mutant,locked in yeast form,protected mice from subsequent lethal C.albicans infection.Deficiency of Dectin-2,a fungus-derivedα-mannan recognition receptor,completely blocked flo8 mutant-induced protection.Mechanistically,the flo8 mutant-induced Dectin-2/CARD9-mediated IL-10 production in DCs and macrophages to block thymus atrophy by inhibiting the C.albicans-induced apoptosis of thymic T cells,which facilitated the continuous output of naive T cells from the thymus to the spleen.Continuous recruitment of naive T cells to the spleen enhanced Th1-biased antifungal immune responses.Consequently,depletion of CD4^(+)T cells or blockade of IL-10 receptor function using specific antibodies in mice completely blocked the protective effects of flo8 mutant priming against C.albicans infection.Moreover,mannans exposed on the surface of the flo8 mutant were responsible for eliciting protective immunity by inhibiting the C.albicans-induced apoptosis of thymic T cells to sustain the number of naive T cells in the spleen.Importantly,priming with the flo8 mutant extensively protected mice from polymicrobial infection caused by cecal ligation and puncture(CLP)by enhancing Th1-biased immune responses.Together,our findings imply that targeting FLO8 in C.albicans elicits protective immune responses against polymicrobial infections and that mannans extracted from the flo8 mutant are potential immunotherapeutic candidate(s)for controlling infectious diseases.展开更多
Background: The clinical significance of the detection of Candida albicans on mucous membranes of the respiratory or intestinal tract from patients in intensive care units is still not finally clarified. Many patients...Background: The clinical significance of the detection of Candida albicans on mucous membranes of the respiratory or intestinal tract from patients in intensive care units is still not finally clarified. Many patients reveal colonization, although, despite increased risk, there are only a few invasive infections detectable. Therefore, antimycotic therapy in this setting is strongly discouraged. In reality, however, many patients receive antimycotics as a pre-emptive therapy. To elucidate this point, a literature research was performed. Results: In the light of new results on the pathogenicity of C.albicans, the recommendation not to treat should be discussed anew. Without becoming invasive, C.albicans influences the immune system negatively in an anti-inflammatory sense (Th2) by means of at least two distinct mechanisms [action on toll like receptors (TLR), production of farnesol], which will be discussed. Conclusion: It is believed that patients in the phase of CARS or MARS can be further endangered by concomitant colonization of mucous membranes by C.albicans, i.e., in the sense of an anti-inflammatory immune response. Treatment with azole preparations, like fluconazole, which interacts with ergosterol synthesis in this phase of the disease, may trigger an additional effect on the patient, through increase of farnesol concentration by way of a negative feedback. Results of animal experiments on the immune system and concomitant therapeutic consequences indicate the need for verification through clinical trials.展开更多
Objective: This study was designed to evaluate whether p62/SQSTM1 (hereafter referred to as p62) is involved in the immune response of macrophages against challenge byCandida albicans (C. albicans).Methods: We culture...Objective: This study was designed to evaluate whether p62/SQSTM1 (hereafter referred to as p62) is involved in the immune response of macrophages against challenge byCandida albicans (C. albicans).Methods: We cultured bone marrow-derived macrophages (BMDMs) to investigate the immune response to challenge byC. albicans. The p62 gene was knocked down by transfection with p62 small interfering RNA (siRNA) in the p62 siRNA group. BMDMs transfected with nonsense siRNA served as the negative control (NC) group. These two groups of BMDMs were challenged withC. albicans in vitro. We detected p62 expression through quantitative reverse transcription PCR and western blotting. The phagocytosis ability of BMDMs was evaluated by flow cytometry and microscopic examination using an Olympus FV1000 laser scanning confocal microscope. Moreover, we determined the level of reactive oxygen species (ROS) in BMDMs. The mRNA levels of proinflammatory cytokines were determined by quantitative reverse transcription PCR.Results: After stimulation byC. albicans, the relative expression of p62 mRNA was increased in a dose-dependent manner, the relative expression of p62 and the ratio of BMDMs toC. albicans is 1.893 ± 0.2156 (1:1,P < 0.05), 2.873 ± 0.4787 (1:3,P < 0.05) and 3.556 ± 0.2892 (1:5,P < 0.01). The p62 protein level was also increased. After transfection with p62 siRNA, the mRNA and protein levels of p62 were significantly decreased in BMDMs (P < 0.05). After 0.5, 1 and 2 hours of co-culture of BMDMs withC. albicans, flow cytometry showed that the phagocytosis rates ofC. albicans by BMDMs were significantly lower in the p62 siRNA group than in the NC group (39.70 ± 1.69%vs. 55.23 ± 0.72%, 46.70 ± 0.89%vs. 60.80 ± 1.78%, 51.90 ± 0.98%vs. 64.43 ± 2.0%, respectively, allP < 0.05). Consistent results were seen in the production of ROS (4269 ± 392.6vs. 13426 ± 1859.7, 4967 ± 721.2vs. 13687 ± 2611.2, 7647 ± 1950.0vs. 17719 ± 1814.2, respectively, allP < 0.05). The ROS levels were higher in BMDMs of the NC group than in BMDMs transfected with p62 siRNA at 0.5, 1, and 2 hours after treatment withC. albicans. BMDMs was co-cultured withC. albicans for 4 and 12 hours, the mRNA levels of interleukin-1β and interleukin-18 in NCs were also higher than p62 siRNA group, interleukin-1β: (6.14 ± 1.63vs. 12.12 ± 0.54, 8.81 ± 0.86vs. 26.2 ± 4.67, respectively, allP < 0.05), IL-18: (0.38 ± 0.02vs. 0.97 ± 0.06, 0.44 ± 0.02vs. 2.23 ± 0.46, respectively, allP < 0.05).Conclusion: p62 plays an important role in the process of phagocytosis in BMDMs challenged byC. albicans through ROS production and expression of proinflammatory cytokines.展开更多
复发性外阴阴道假丝酵母菌病(Recurrent candidiasis of vulva and vagina,RVVC)病因复杂,主要原因有机体免疫防御机制的变化,宿主局部因素,假丝酵母菌的菌群多样性变化等。认识、了解及掌握上述因素,对临床工作者有效防治RVVC起着非常...复发性外阴阴道假丝酵母菌病(Recurrent candidiasis of vulva and vagina,RVVC)病因复杂,主要原因有机体免疫防御机制的变化,宿主局部因素,假丝酵母菌的菌群多样性变化等。认识、了解及掌握上述因素,对临床工作者有效防治RVVC起着非常重要作用。展开更多
基金supported by National Key Research and Development Program of China(2021YFC2301405)Chongqing Talent Program(No.CQYC202003220).
文摘Objective:Candida albicans is a common fungal pathogen that triggers complex host defense mechanisms,including coordinated innate and adaptive immune responses,to neutralize invading fungi effectively.Exploring the immune microenvironment has the potential to inform the development of therapeutic strategies for fungal infections.Methods:The study analyzed individual immune cell profiles in peripheral blood mononuclear cells from Candida albicans-infected mice and healthy control mice using single-cell transcriptomics,fluorescence quantitative PCR,and Western blotting.We investigated intergroup differences in the dynamics of immune cell subpopulation infiltration,pathway enrichment,and differentiation during Candida albicans infection.Results:Our findings indicate that infiltration of CD4^(+)naive cells,regulatory T(Treg)cells,and Microtubules(MT)-associated cells increased after infection,along with impaired T cell activity.Notably,CD4^(+) T cells and plasma cells were enhanced after infection,suggesting that antibody production is dependent on T cells.In addition,we screened 6 hub genes,transcription factor forkhead box protein 3(Foxp3),cytotoxic T-lymphocyte associated protein 4(CTLA4),Interleukin 2 Receptor Subunit Beta(Il2rb),Cd28,C-C Motif Chemokine Ligand 5(Ccl5),and Cd27 for alterations associated with CD4^(+) T cell differentiation.Conclusions:These results provide a comprehensive immunological landscape of the mechanisms of Candida albicans infection and greatly advance our understanding of adaptive immunity in fungal infections.
基金This work was supported by the National Natural Science Foundation of China(31970889,31622023 to X.M.J.and 81902039 to Q.Z.L.)the Innovation Program of Shanghai Municipal Education Commission(201901070007E00022 to X.M.J.)+5 种基金the Outstanding Academic Leader Program of the Shanghai Health and Family Planning Commission(2017BR024 to X.M.J.)the Shuguang Program of the Shanghai Municipal Education Commission(17SG24 to X.M.J.)the Fundamental Research Funds for the Central Universities(X.M.J.)by a member of the Innovative Research Team of High-Level Local University in Shanghai(X.M.J.)the Key fund for basic research of Shanghai Science and Technology Commission(20JC1417700 to X.M.J.)Shanghai Municipal Natural Science Foundation(19ZR1461800 to D.D.L.).
文摘The morphological switch between yeast and hyphae of Candida albicans is essential for its interaction with the host defense system.However,the lack of understanding of host-pathogen interactions during C.albicans infection greatly hampers the development of effective immunotherapies.Here,we found that priming with the C.albicans FLO8-deficient(flo8)mutant,locked in yeast form,protected mice from subsequent lethal C.albicans infection.Deficiency of Dectin-2,a fungus-derivedα-mannan recognition receptor,completely blocked flo8 mutant-induced protection.Mechanistically,the flo8 mutant-induced Dectin-2/CARD9-mediated IL-10 production in DCs and macrophages to block thymus atrophy by inhibiting the C.albicans-induced apoptosis of thymic T cells,which facilitated the continuous output of naive T cells from the thymus to the spleen.Continuous recruitment of naive T cells to the spleen enhanced Th1-biased antifungal immune responses.Consequently,depletion of CD4^(+)T cells or blockade of IL-10 receptor function using specific antibodies in mice completely blocked the protective effects of flo8 mutant priming against C.albicans infection.Moreover,mannans exposed on the surface of the flo8 mutant were responsible for eliciting protective immunity by inhibiting the C.albicans-induced apoptosis of thymic T cells to sustain the number of naive T cells in the spleen.Importantly,priming with the flo8 mutant extensively protected mice from polymicrobial infection caused by cecal ligation and puncture(CLP)by enhancing Th1-biased immune responses.Together,our findings imply that targeting FLO8 in C.albicans elicits protective immune responses against polymicrobial infections and that mannans extracted from the flo8 mutant are potential immunotherapeutic candidate(s)for controlling infectious diseases.
文摘Background: The clinical significance of the detection of Candida albicans on mucous membranes of the respiratory or intestinal tract from patients in intensive care units is still not finally clarified. Many patients reveal colonization, although, despite increased risk, there are only a few invasive infections detectable. Therefore, antimycotic therapy in this setting is strongly discouraged. In reality, however, many patients receive antimycotics as a pre-emptive therapy. To elucidate this point, a literature research was performed. Results: In the light of new results on the pathogenicity of C.albicans, the recommendation not to treat should be discussed anew. Without becoming invasive, C.albicans influences the immune system negatively in an anti-inflammatory sense (Th2) by means of at least two distinct mechanisms [action on toll like receptors (TLR), production of farnesol], which will be discussed. Conclusion: It is believed that patients in the phase of CARS or MARS can be further endangered by concomitant colonization of mucous membranes by C.albicans, i.e., in the sense of an anti-inflammatory immune response. Treatment with azole preparations, like fluconazole, which interacts with ergosterol synthesis in this phase of the disease, may trigger an additional effect on the patient, through increase of farnesol concentration by way of a negative feedback. Results of animal experiments on the immune system and concomitant therapeutic consequences indicate the need for verification through clinical trials.
基金The study was supported by the National Natural Science Foundation of China(Nos.82103749,81773338,and 82173432)ChineseAcademy ofMedicalSciencesMedicine andHealthTechnology InnovationProject(No.2017-I2M-1-017)+1 种基金Natural Science Foundation of Jiangsu Province(No.BK20190144)the Nanjing Incubation Program for National Clinical Research Center(No.2019060001).
文摘Objective: This study was designed to evaluate whether p62/SQSTM1 (hereafter referred to as p62) is involved in the immune response of macrophages against challenge byCandida albicans (C. albicans).Methods: We cultured bone marrow-derived macrophages (BMDMs) to investigate the immune response to challenge byC. albicans. The p62 gene was knocked down by transfection with p62 small interfering RNA (siRNA) in the p62 siRNA group. BMDMs transfected with nonsense siRNA served as the negative control (NC) group. These two groups of BMDMs were challenged withC. albicans in vitro. We detected p62 expression through quantitative reverse transcription PCR and western blotting. The phagocytosis ability of BMDMs was evaluated by flow cytometry and microscopic examination using an Olympus FV1000 laser scanning confocal microscope. Moreover, we determined the level of reactive oxygen species (ROS) in BMDMs. The mRNA levels of proinflammatory cytokines were determined by quantitative reverse transcription PCR.Results: After stimulation byC. albicans, the relative expression of p62 mRNA was increased in a dose-dependent manner, the relative expression of p62 and the ratio of BMDMs toC. albicans is 1.893 ± 0.2156 (1:1,P < 0.05), 2.873 ± 0.4787 (1:3,P < 0.05) and 3.556 ± 0.2892 (1:5,P < 0.01). The p62 protein level was also increased. After transfection with p62 siRNA, the mRNA and protein levels of p62 were significantly decreased in BMDMs (P < 0.05). After 0.5, 1 and 2 hours of co-culture of BMDMs withC. albicans, flow cytometry showed that the phagocytosis rates ofC. albicans by BMDMs were significantly lower in the p62 siRNA group than in the NC group (39.70 ± 1.69%vs. 55.23 ± 0.72%, 46.70 ± 0.89%vs. 60.80 ± 1.78%, 51.90 ± 0.98%vs. 64.43 ± 2.0%, respectively, allP < 0.05). Consistent results were seen in the production of ROS (4269 ± 392.6vs. 13426 ± 1859.7, 4967 ± 721.2vs. 13687 ± 2611.2, 7647 ± 1950.0vs. 17719 ± 1814.2, respectively, allP < 0.05). The ROS levels were higher in BMDMs of the NC group than in BMDMs transfected with p62 siRNA at 0.5, 1, and 2 hours after treatment withC. albicans. BMDMs was co-cultured withC. albicans for 4 and 12 hours, the mRNA levels of interleukin-1β and interleukin-18 in NCs were also higher than p62 siRNA group, interleukin-1β: (6.14 ± 1.63vs. 12.12 ± 0.54, 8.81 ± 0.86vs. 26.2 ± 4.67, respectively, allP < 0.05), IL-18: (0.38 ± 0.02vs. 0.97 ± 0.06, 0.44 ± 0.02vs. 2.23 ± 0.46, respectively, allP < 0.05).Conclusion: p62 plays an important role in the process of phagocytosis in BMDMs challenged byC. albicans through ROS production and expression of proinflammatory cytokines.
