Objective To explore the differential expression of the key microfilament cytoskeleton-binding proteins in immature dendritic cells(imDCs)during antigen phagocytosis.Methods Monocytes(MOs)were isolated from peripheral blood of healthy individuals and cultured with recombinant human granulocyte-macrophage colony stimulating factor(rhGM-CSF)and recombinant human interleukin-4(rhIL-4)for 6 days to obtain imDCs.ImDCs were co-cultured with low molecular weight(40 kDa)and high molecular weight(150 kDa)dextrans for 1,3 and 6 hours,respectively.Flow cytometry was used to detect the percentage of imDCs phagocytosing dextran and the expression of immunophenotype molecules.The localization of filamentous actin(F-actin),PFN1,WASP,and α-actinin in cells were observed by immunofluorescence imaging.The differential expression of MCBPs at the mRNA and protein levels were respectively detected by q-PCR and Western blotting.Finally,the MCBPs with the highest component coefficients were identified based on the stepwise regression and principal component analysis method in systems biology algorithms.Results During the process of antigen phagocytosis,imDCs phagocytized low molecular weight antigens at a faster rate,with a phagocytic duration of approximately three hours.Their cell phenotypes and morphology gradually differentiated into mDCs,and F-actin remodeling was occurred significantly.The expression of MCBPs such as PFN1,CDM,WASP,CAPZB,Filamin A,α-actinin were downregulated,while the expression of WAVE1,Arp2/3 complex,and Fascin were upregulated.The mRNA expression of signaling protein Rac1 was upregulated,while the mRNA expressions of CDC42 and RhoA were downregulated.The immunofluorescence results showed that PFN1,WASP,and α-actinin were transposed during the antigen phagocytosis process of imDCs.The results of stepwise regression and principal component analysis showed that PFN1 had the highest component coefficient.Conclusions PFN1 may be a key MCBPs involved in the process of antigen phagocytosis of imDCs,which is of great significance for further understanding the relationship between changes in the cytoskeleton structure of imDCs and their immunological functions.

Objective To construct type Ⅰ collagen gels with different stiffness and to investigate the effects of three-dimensional(3D)culture environments of the gels on the morphology,free migration ability,and cell killing function of natural killer(NK)cells.Methods Type Ⅰ collagen was isolated from the tails of Sprague Dawley(SD)rats and collagen gels with different levels of stiffnesses were prepared accordingly.The microstructure of the collagen gels was observed by laser confocal microscopy.The stiffness of the collagen gels was assessed by measuring the plateau modulus with a rheometer.NK-92MI cells were cultured in collagen gels with different levels of stiffness.The morphology of NK-92MI cells was observed by inverted microscope.High content imaging system was used to record the free migration process of NK-92MI cells and analyze the migration speed and distance.NK-92MI cells were cultured with type Ⅰcollagen gels with different levels of stiffness for 24 h and 48 h and,then,co-cultured with human colorectal DLD-1,a human adenocarcinoma epithelial cell line.CCK8 assay was performed to determine the proliferation rate of DLD-1 cells and analyze the cell killing ability of NK-92MI cells.Results Low-stiffness type Ⅰ collagen gel and high-stiffness type Ⅰcollagen gel with the respective stiffness of(10.970±2.10)Pa and(114.50±3.40)Pa were successfully prepared.Compared with those cultured with the low-stiffness type Ⅰ collagen gel,the NK-92MI cells in the high-stiffness type Ⅰ collagen gel showed a more elongated shape(P<0.05),the mean area of the cells was reduced([69.88±26.97]μm2 vs.[46.59±21.62]μm2,P<0.05),the roundness of the cells decreased(0.82±0.12 vs.0.78±0.18,P<0.05),cell migration speed decreased([2.50±0.91]μm/min vs.[1.70±0.72]μm/min,P<0.001)and the migration distance was shortened([147.10±53.74]μm vs.[98.03±40.95]μm,P<0.0001),with all the differences being statistically significant.Compared with those cultured with the low-stiffness type Ⅰ collagen gel,NK-92MI cells cultured with high-stiffness type Ⅰ collagen gel for 24 h could promote DLD-1 cell proliferation,with the proliferation rate being(46.39±12.79)%vs.(65.87±4.45)%(P<0.05)and reduce the cell killing ability.Comparison of the cells cultured for 48 h led to similar results,with the proliferation rates being(31.36±2.88)%vs.(74.57±2.16)%(P<0.05),and the differences were all statistically significant.Conclusion The 3D culture environment of type Ⅰ collagen gels with different levels of stiffness alters the morphology,migration ability,and killing function of NK-92MI cells.This study provides the research basis for exploring and understanding the mechanisms by which the biomechanical microenvironment affects the immune response of NK cells,as well as laying the theoretical foundation for optimizing immunotherapy protocols.

Objective: To analyze the influence of atmospheric particulate matters (PM_2.5 and PM₁₀) on low-birth-weight (LBW) infants at different periods of gestation. Methods: We conducted a systematic literature search for 2 471 articles related to particulate matter and LBW published from January 1st 2000 to January 1st 2016 using the PubMed, Cochrane Library, Web of Science, Science Direct, Chinese Web of Knowledge, Wanfang and Weipu, and the keywords were" air pollution" , "adverse birth outcomes" , "adverse pregnancy outcomes" , "low birth weight/LBW" . According to criteria, 27 literatures were selected and included. Metafor package of the R 3.1.1 Software was used to check the heterogeneity and merge the effect value of the selected literatures, and sensitivity analysis and publication bias were detected and adjusted. Results: A total of 2 471 studies selected form the databases, 27 enrolled in this analysis according to the inclusion and exclusion criteria. Each 10 μg/m³ increase in PM_2.5 was associated with combined OR values of 1st trimester, 2nd trimester, 3rd trimester and entire gestation at 1.02(95% CI: 0.87-1.19), 1.03 (95% CI: 0.91-1.16) , 1.07 (95%CI: 1.04-1.11) and 1.09 (95%CI: 1.04-1.15), respectively. And 10 μg/m³ increase in PM₁₀ was associated with combined OR values of 1st trimester, 2nd trimester, 3rd trimester and entire gestation at 1.66 (95%CI: 1.06-2.61), 1.58 (95%CI:1.28-1.95) , 1.38 (95%CI: 1.23-1.56) and 1.04 (95%CI: 0.99-1.09), respectively. After adjusting the bias of publication, each 10 μg/m³ increase in PM_2.5 was associated with the risk of low birth weight at 1.11 (95%CI: 1.02-1.21). Conclusion This meta analysis supports an adverse impact of maternal exposure to particulate air pollution on low birth weight, varying in effects by exposure period.

Objective To investigate online dating status and human immunodeficiency virus (HIV)infection among men who have sex with men (MSM)in Chongqing,and provide basis for effective intervention in HIV infec-tion among MSM.Methods 206 MSM in Chongqing were performed structured interview and questionnaire survey, MSM who didn’t conduct HIV testing within half a year were performed laboratory screening,sociological popula-tion characteristics and influencing factors of HIV in MSM were analyzed.Results The average age of 206 MSM was (22.08±1 .81)years old,137 (66.50%)received college education and above,HIV infection rate was 21 .36%(44/206).HIV infection rate in MSM who had no fixed partners was higher than those who had fixed partners;the more sexual partners they had,the greater the risk of HIV infection they got;HIV infection rate in MSM who had sex with unfamiliar persons or strangers was higher than those who had sex with familiar partners;the higher rate of condom use in sexual behavior,the lower rate of HIV infection was,there were significant differences among the groups(all P <0.05).Condom use among MSM with different educational levels was significantly different(all P <0.05).Conclusion HIV infection rate in MSM is high in this city,it is necessary to strengthen education about health,network partner,and behavioral intervention,reduce the bridge population connecting MSM network,es-tablish social support system of homosexuality,and reduce the risk of HIV infection in MSM.

Objective To examine the current status of the sexual behavior among out‐of‐school adolescent men who have sex with men(MSM)and analyze the influential factors of AIDS infection in order to provide countermeasures.Methods The software SPSS 16.0 was used for cross table analysis and chi square test of questionnaire data and HIV detection data.Results The HIV infection rate was 21.36%.The household registration ,the only child ,living state ,coming out of the closet ,fixed sex‐ual partner ,the way they know sexual partners had no significant effects on HIV infection(P>0.05).Having multiple sexual partners(P<0.05) ,unfamiliar with sexual partners(P<0.05) ,having sex with network friends(P<0.05) ,no condom use in sexual life(P<0.01) ,having no regular HIV testing(P<0.01)were significantly related to HIV infection.Conclusion Reduc‐ing the sexual behavior among out‐of‐school adolescent MSM ,carrying out HIV counseling and testing ,promoting the use of condoms contribute to the reduction of HIV infection.