Background The mechanism of chronic immune activation and impairment of HIV-specific immune responses during chronic infection is not fully understood. However, it is known that high immune activation leads to more ra...Background The mechanism of chronic immune activation and impairment of HIV-specific immune responses during chronic infection is not fully understood. However, it is known that high immune activation leads to more rapid progression to AIDS. We hypothesize that CD4^＋ T cell-mediated viral antigen presentation contributes to this pathologic immune activation in HIV-infected individuals. Methods HIV-specific T cells, responding to noninfectious HIV-1 virions as antigen, were measured by flow cytometric assays. These experimental conditions reflect the in vivo condition where noninfectious HIV-1 represents more than 99% of the antigens. Results CD4^＋ T cells purified from HIV-infected individuals were capable of cross presenting exogenous noninfectious HIV-1 virions to HIV-1-specific CD8^＋ T cells. Cross presentation required the entry of HIV-1 to CD4^＋ T cells and antigen translocation from endoplasmic reticulum to the Golgi complex. Blocking CD4^＋ mediated activation of HIV-specific CD8^＋ T cells and redirecting the viral antigens to antigen presenting cells improved HIV-specific T cell responses. Contusions One possible cause of chronic immune activation and impairment of HIV-1 specific T cell responses is represented by HIV-1 harboring CD4^＋ T cells cross presenting HIV-1 antigen to activate CD8^＋ T cells. This new mechanism provides the first evidence that cross presentation of noninfectious HIV-1 virions play a role in the immunopathogenesis of HIV-1 infection.展开更多
Objective:To investigate the prevalence of microbial antigenic components of circulating immune complexes amongst grades of CD4 T lymphocyte counts in HIV sero positive and seronegative participants.Methods:Polyethele...Objective:To investigate the prevalence of microbial antigenic components of circulating immune complexes amongst grades of CD4 T lymphocyte counts in HIV sero positive and seronegative participants.Methods:Polyethelene glycol(PEG-600) and buffering methods of precipitation and dissociation of immune complexes was used to generate immune solution from sera of 100 HIV sero-positive and 100 HIV sero-negative participants.These were categorized into 3 grades based on CD4 count:】 500 cell/mm,200-499 cell/mm3 and 【200 cell/mm3.The immune solutions were assayed using membrane based immunoassay and antibody titration, along side its unprocessed serum for detection of various microbial antigens and or antibodies. CD4 T cell counts were estimated using Patec Cyflow SL-3 Germany.Results:Antigenic component of immune complexes of various infectious agents was detected in 99 and 70 HIV seropositive and HIV sero-negative participants,respectively.In group A,there were 10 HIV positive participants,including 4(40.0%) had circulating immune complexes(CICs) due to Salmonella species only:1(10.0%) due to Salmonella-Plasmodium falciparum(P.falciparum),SalmonellaP. falciparum-HCV and P.falciparum antigens,respectively.In group B,45(45.4%) HIV seropositive participants with CICs had CD4 T lymphocyte count between 200-499 cells/mm^3.Out of these,20(44.4%) had CICs due to Salmonella species only:9(20%) due to Salmonella-P. falciparum.In group C,there were 44(44.4%) HIV sero-positive participants,including 3(6.8%) due to Salmonella species only:24(54.4%) due to Salmonella-P.falciparum:2(4.5%) due to P. falciparum only.Conclusions:In HIV sero-positive participants,presence of heterogeneity of Salmonella species-P.falciparum antigens was highly incriminated in CD4 count depletion but not homogeneity of malaria parasites antigens.Malaria parasites antigens only were incriminated in CD4^+ count depletion amongst HIV sero-negative participants.Before taking any decision on the management of HIV-1-positive individuals,their malaria and Salmonella paratyphi status should be assessed,but not malaria status alone.展开更多
AIM: To investigate the role of regulatory T(Treg) cells in CD4+ T cell-mediated bladder autoimmune inflammation.METHODS: Urothelium-ovalbumin(URO-OVA)/OTII mice, a double transgenic line that expresses the membrane f...AIM: To investigate the role of regulatory T(Treg) cells in CD4+ T cell-mediated bladder autoimmune inflammation.METHODS: Urothelium-ovalbumin(URO-OVA)/OTII mice, a double transgenic line that expresses the membrane form of the model antigen(Ag) OVA as a self-Ag on the urothelium and the OVA-specific CD4+ T cell receptor specific for the I-Ab/OVA323-339 epitope in the periphery, were developed to provide an autoimmune environment for investigation of the role of Treg cells in bladder autoimmune inflammation. To facilitate Treg cell analysis, we further developed URO-OVAGFP-Foxp3/OT-II mice, a derived line of URO-OVA/OT-II mice that express the green fluorescent protein(GFP)-forkhead box protein P3(Foxp3) fusion protein. RESULTS: URO-OVA/OT-II mice failed to develop bladder inflammation despite the presence of autoreactive CD4+ T cells. By monitoring GFP-positive cells, bladder infiltration of CD4+ Treg cells was observed in URO-OVAGFP-Foxp3/OTII mice. The infiltrating Treg cells were functionally active and expressed Treg cell effector molecule as well as marker m RNAs including transforming growth factor-b, interleukin(IL)-10, fibrinogen-like protein 2, and glucocorticoid-induced tumor necrosis factor receptor(GITR). Studies further revealed that Treg cells from URO-OVAGFP-Foxp3/OT-II mice were suppressive and inhibited autoreactive CD4+ T cell proliferationand interferon(IFN)-g production in response to OVA Ag stimulation. Depletion of GITR-positive cells led to spontaneous development of bladder inflammation and expression of inflammatory factor m RNAs for IFN-g, IL-6, tumor necrosis factor-a and nerve growth factor in URO-OVAGFP-Foxp3/OT-II mice. CONCLUSION: Treg cells specific for bladder epithelial Ag play an important role in immunological homeostasis and the control of CD4+ T cell-mediated bladder autoimmune inflammation.展开更多
AIM: Crohn's disease(CD)and ulcerative colitis(UC)are multifactorial diseases with a significant genetic background.Apart from CARD15/NOD2 gene, evidence is accumulating that molecules related to the innate immune...AIM: Crohn's disease(CD)and ulcerative colitis(UC)are multifactorial diseases with a significant genetic background.Apart from CARD15/NOD2 gene, evidence is accumulating that molecules related to the innate immune response such as CD14 or Toll-like receptor 4 (TLR4), are involved in their pathogenesis. In further exploring the genetic background of these diseases, we investigated the variations in the CARD15/NOD2 gene (Arg702Trp,Gly908Arg and Leu1007fsinsC), and polymorphisms in the TLR4 gene (Asp299Gly and Thr399Ile) as well as in the promoter of the CD14 gene (T/C at position -159) in Greek patients with CD and UC.METHODS: DNA was obtained from 120 patients with CD,85 with UC and 100 healthy individuals. Genotyping was performed by allele specific PCR or by PCR-RFLP analysis.RESULTS: The 299Gly allele frequency of the TLR4 gene and the T allele and TT genotype frequendes of the CD14 promoter were significantly higher in CD patients only compared to healthy individuals (P = 0.026＜0.05; P = 0.0048＜0.01 and P= 0.047＜0.05 respectively). Concerning the NOD2/CARD15mutations the overall presence in CD patients was significantly higher than that in UC patients or in controls.Additionally, 51.67% of the CD patients were carriers of a TLR4 and/or CD14 polymorphic allele and at least one variant of the NOD2/CARD15, compared to 27% of the UC patients. It should be pointed out that both frequencies significantly increased as compared with the 10% frequency of multiple carriers found in healthy controls. A possible interaction of the NOD2/CARD15 with TLR4 and especially CD14, increased the risk of developing inflammatory bowel disease (IBD).CONCLUSION: Our results indicate that co-existence of a mutation in either the TLR4 or CD14 gene, and in NOD2/CARD15is associated with an increased susceptibility to developing CD compared to UC, and to developing either CD or UC compared to healthy individuals.展开更多
Summary: The role of CD80/CD86 and CTLA-4 in the pathogenesis of systemic lupus erythematosus and their clinical significance was investigated. By using RT-PCR technique, the expression of CD80/CD86 and CTLA-4 mRNA in...Summary: The role of CD80/CD86 and CTLA-4 in the pathogenesis of systemic lupus erythematosus and their clinical significance was investigated. By using RT-PCR technique, the expression of CD80/CD86 and CTLA-4 mRNA in peripheral blood mononuclear cells (PBMC) were semiquantitatively detected in 32 patients with active SLE. The results showed that the percentage of positive CD86 expression in active SLE was increased significantly as compared with normal controls (90.63 % vs 60.00 %, P<0.01). The mean level of CD86 mRNA expression in active SLE group was markedly higher than in the normal controls (0.6410+0.0174 vs 0.4510+0.0402, P<0.001). Compared with normal controls, the percentage of positive CTLA-4 expression and the mean level of CTLA-4 mRNA expression in active SLE group were both increased significantly (both P<0.01). There was no statistical differences in positive rate of CD80 and the average level of CD80 mRNA between the two groups (both P>0.05). It was concluded that the aberrant expression of CD86 and CTLA-4 might play an important role in the activity and development of SLE.展开更多
Background: Human immunodeficiency virus and hepatitis B and C viruses are endemic in sub- Saharan African countries including Nigeria. Researchers have studied the burden of co-infection of HIV with hepatitis B and h...Background: Human immunodeficiency virus and hepatitis B and C viruses are endemic in sub- Saharan African countries including Nigeria. Researchers have studied the burden of co-infection of HIV with hepatitis B and hepatitis C but the risk factors and clinical presentation have not been much addressed especially in children. Methodology: This was a prospective cross sectional study that determined the prevalence, risk factors, clinical features, baseline CD4<sup>+</sup> count, CD4<sup>+</sup> percentage, and alanine aminotransferase (ALT) of newly diagnosed, HAART na?ve HIV co-infection among children who were managed at a Tertiary Hospital in Ilorin, Nigeria. Result: Of the 60 HIV- infected children recruited, 11.7% had HIV co-infection with HBV or HCV. Children with co-infec- tions (mean age 8.43 ± 2.37 years) were significantly older than their HIV mono-infected counterparts (mean age 5.25 ± 3.96 years) (p = 0.011). There was no significant difference between HIV monoinfection and HIV co-infection with respect to gender (p = 0.758), ethnicity (p = 0.707), religion of parents (p = 0.436), family type (p = 0.184), social class (p = 0.535), previous transfusion (p = 0.053), scarification (p = 0.612), female genital mutilation (p = 0.778), and sharing of clippers (p = 0.806). The mean BMI, immunological staging (p = 0.535), baseline ALT (p = 0.940), and mean baseline CD4<sup>+</sup> count (p = 0.928) were comparable. However, the body mass index of HIV co-infec- ted children decreased with age up till age 10 years. Conclusion: There were no risk factors, nor clinical features predictive of co-infection identified in this study. Co-infection did not negatively impact baseline, CD4<sup>+</sup> count and ALT.展开更多
Summary： To investigate the expression and significance of CD28 and CTLA4 on T cells in bone marrow of aplastic anemia （AA） mice, in vitro bone marrow mononuclear cells （BMMNCs） were activated through being incub...Summary： To investigate the expression and significance of CD28 and CTLA4 on T cells in bone marrow of aplastic anemia （AA） mice, in vitro bone marrow mononuclear cells （BMMNCs） were activated through being incubated with PHA （15 μg/mL）. The expression of CD28 and CTLA4 on T cells incubated with or without PHA was detected by two-color flow cytometry. The expression of CD28 and CTLA4 was significantly increased after PHA stimulation. In the AA mice. the expression of CD28 with or without PHA stimulation was both higher than that in the normal mice （both P〈0.01）, but the expression of CTLA4 with or without PHA stimulation showed no significant difference in comparison to that in the normal mice （both P〉0.05）. In the AA mice, there were more activation and activated potential of T cells than the normal, and the abnormal expression of CD28 and CTLA4 may participate in immunological disorder mediated by T cells.展开更多
Parasite-specific CD8+ T cells have been shown to transfer protection against nLeishmania major in susceptible BALB/c mice.An epitope-tagged expression library was used to identify the antigen recognized by a protecti...Parasite-specific CD8+ T cells have been shown to transfer protection against nLeishmania major in susceptible BALB/c mice.An epitope-tagged expression library was used to identify the antigen recognized by a protective CD8+ T cells clone. The expression library allowed recombinant proteins made in bacteria to be captured by macrophages for presentation to T cells restricted to major histompatibility complex class n. A conserved 36-kilodalton member of the tryptophanaspartic acid repeat family of proteins was identified that was expressed in both stages of the parasite life cycle. A 24-kilodalton portion of this antigen protected susceptible mice when administered as a vaccine with interleukin-12before injection.展开更多
The T-cell-mediated immune response is implicated in many clinical hepatic injuries, such as autoimmune hepatitis and acute virus hepatitis. CD24 is widely expressed by different immune cells and plays an important ro...The T-cell-mediated immune response is implicated in many clinical hepatic injuries, such as autoimmune hepatitis and acute virus hepatitis. CD24 is widely expressed by different immune cells and plays an important role in the pathogenesis of many autoimmune diseases. However, the role of CD24 in T-cell-mediated liver injury has not been elucidated until now. Here we showed that CD24 deficiency protects mice from concanavalin A (ConA)-induced fulminant liver injury by reducing serum interferon-γ (IFN-γ) levels. CD24 expression by hepatic T cells was markedly increased following ConA challenge. Moreover, decreased IFN-γ production by hepatic CD4^(+) T cells in CD24-deficient mice was detected, which was correlated with downregulated phosphorylation of STAT1 in hepatic tissue. In vitro experiments also supported the conclusion that CD24 deficiency impaired IFN-γ production by CD4^(+) T cells following ConA, CD3/CD28 and phorbol myristate acetate/ionomycin stimulation. Our study suggests that CD24 deficiency confers hepatoprotection by decreasing CD4^(+) T-cell-dependent IFN-γ production in vivo, which suggests that CD24 might be a potential target molecule for reducing clinical hepatitis.展开更多
AIM:To test the hypothesis that liver cirrhosis is associated with mobilization of hematopoietic progenitor cells. METHODS:Peripheral blood samples from 72 patients with liver cirrhosis of varying etiology were analyz...AIM:To test the hypothesis that liver cirrhosis is associated with mobilization of hematopoietic progenitor cells. METHODS:Peripheral blood samples from 72 patients with liver cirrhosis of varying etiology were analyzed by flow cytometry.Identified progenitor cell subsets were immunoselected and used for functional assays in vitro. Plasma levels of stromal cell-derived factor-1(SDF-1) were measured using an enzyme linked immunosorbent assay.RESULTS:Progenitor cells with a CD133 + /CD45 + CD14 + phenotype were observed in 61%of th patients.Between 1%and 26%of the peripheral bloo mononuclear cells(MNCs)displayed this phenotype Furthermore,a distinct population of c-kit + progenito cells(between 1%and 38%of the MNCs)could b detected in 91%of the patients.Additionally,18% of the patients showed a population of progenito cells(between 1%and 68%of the MNCs)that wa characterized by expression of breast cancer resistanc protein-1.Further phenotypic analysis disclosed tha the circulating precursors expressed CXC chemokin receptor 4,the receptor for SDF-1.In line with thi finding,elevated plasma levels of SDF-1 were presen in all patients and were found to correlate with th number of mobilized CD133 + progenitor cells.展开更多
基金This study was supported by a grant from the Major Basic Project of China (973) (No. 2005CB522903).
文摘Background The mechanism of chronic immune activation and impairment of HIV-specific immune responses during chronic infection is not fully understood. However, it is known that high immune activation leads to more rapid progression to AIDS. We hypothesize that CD4^＋ T cell-mediated viral antigen presentation contributes to this pathologic immune activation in HIV-infected individuals. Methods HIV-specific T cells, responding to noninfectious HIV-1 virions as antigen, were measured by flow cytometric assays. These experimental conditions reflect the in vivo condition where noninfectious HIV-1 represents more than 99% of the antigens. Results CD4^＋ T cells purified from HIV-infected individuals were capable of cross presenting exogenous noninfectious HIV-1 virions to HIV-1-specific CD8^＋ T cells. Cross presentation required the entry of HIV-1 to CD4^＋ T cells and antigen translocation from endoplasmic reticulum to the Golgi complex. Blocking CD4^＋ mediated activation of HIV-specific CD8^＋ T cells and redirecting the viral antigens to antigen presenting cells improved HIV-specific T cell responses. Contusions One possible cause of chronic immune activation and impairment of HIV-1 specific T cell responses is represented by HIV-1 harboring CD4^＋ T cells cross presenting HIV-1 antigen to activate CD8^＋ T cells. This new mechanism provides the first evidence that cross presentation of noninfectious HIV-1 virions play a role in the immunopathogenesis of HIV-1 infection.
文摘Objective:To investigate the prevalence of microbial antigenic components of circulating immune complexes amongst grades of CD4 T lymphocyte counts in HIV sero positive and seronegative participants.Methods:Polyethelene glycol(PEG-600) and buffering methods of precipitation and dissociation of immune complexes was used to generate immune solution from sera of 100 HIV sero-positive and 100 HIV sero-negative participants.These were categorized into 3 grades based on CD4 count:】 500 cell/mm,200-499 cell/mm3 and 【200 cell/mm3.The immune solutions were assayed using membrane based immunoassay and antibody titration, along side its unprocessed serum for detection of various microbial antigens and or antibodies. CD4 T cell counts were estimated using Patec Cyflow SL-3 Germany.Results:Antigenic component of immune complexes of various infectious agents was detected in 99 and 70 HIV seropositive and HIV sero-negative participants,respectively.In group A,there were 10 HIV positive participants,including 4(40.0%) had circulating immune complexes(CICs) due to Salmonella species only:1(10.0%) due to Salmonella-Plasmodium falciparum(P.falciparum),SalmonellaP. falciparum-HCV and P.falciparum antigens,respectively.In group B,45(45.4%) HIV seropositive participants with CICs had CD4 T lymphocyte count between 200-499 cells/mm^3.Out of these,20(44.4%) had CICs due to Salmonella species only:9(20%) due to Salmonella-P. falciparum.In group C,there were 44(44.4%) HIV sero-positive participants,including 3(6.8%) due to Salmonella species only:24(54.4%) due to Salmonella-P.falciparum:2(4.5%) due to P. falciparum only.Conclusions:In HIV sero-positive participants,presence of heterogeneity of Salmonella species-P.falciparum antigens was highly incriminated in CD4 count depletion but not homogeneity of malaria parasites antigens.Malaria parasites antigens only were incriminated in CD4^+ count depletion amongst HIV sero-negative participants.Before taking any decision on the management of HIV-1-positive individuals,their malaria and Salmonella paratyphi status should be assessed,but not malaria status alone.
基金Supported by The National Institutes of Health to Luo Y,No.RO1DK066079
文摘AIM: To investigate the role of regulatory T(Treg) cells in CD4+ T cell-mediated bladder autoimmune inflammation.METHODS: Urothelium-ovalbumin(URO-OVA)/OTII mice, a double transgenic line that expresses the membrane form of the model antigen(Ag) OVA as a self-Ag on the urothelium and the OVA-specific CD4+ T cell receptor specific for the I-Ab/OVA323-339 epitope in the periphery, were developed to provide an autoimmune environment for investigation of the role of Treg cells in bladder autoimmune inflammation. To facilitate Treg cell analysis, we further developed URO-OVAGFP-Foxp3/OT-II mice, a derived line of URO-OVA/OT-II mice that express the green fluorescent protein(GFP)-forkhead box protein P3(Foxp3) fusion protein. RESULTS: URO-OVA/OT-II mice failed to develop bladder inflammation despite the presence of autoreactive CD4+ T cells. By monitoring GFP-positive cells, bladder infiltration of CD4+ Treg cells was observed in URO-OVAGFP-Foxp3/OTII mice. The infiltrating Treg cells were functionally active and expressed Treg cell effector molecule as well as marker m RNAs including transforming growth factor-b, interleukin(IL)-10, fibrinogen-like protein 2, and glucocorticoid-induced tumor necrosis factor receptor(GITR). Studies further revealed that Treg cells from URO-OVAGFP-Foxp3/OT-II mice were suppressive and inhibited autoreactive CD4+ T cell proliferationand interferon(IFN)-g production in response to OVA Ag stimulation. Depletion of GITR-positive cells led to spontaneous development of bladder inflammation and expression of inflammatory factor m RNAs for IFN-g, IL-6, tumor necrosis factor-a and nerve growth factor in URO-OVAGFP-Foxp3/OT-II mice. CONCLUSION: Treg cells specific for bladder epithelial Ag play an important role in immunological homeostasis and the control of CD4+ T cell-mediated bladder autoimmune inflammation.
基金Supported by the EU Project "Sacrohn" N. QLK2-CT-2000-00928.
文摘AIM: Crohn's disease(CD)and ulcerative colitis(UC)are multifactorial diseases with a significant genetic background.Apart from CARD15/NOD2 gene, evidence is accumulating that molecules related to the innate immune response such as CD14 or Toll-like receptor 4 (TLR4), are involved in their pathogenesis. In further exploring the genetic background of these diseases, we investigated the variations in the CARD15/NOD2 gene (Arg702Trp,Gly908Arg and Leu1007fsinsC), and polymorphisms in the TLR4 gene (Asp299Gly and Thr399Ile) as well as in the promoter of the CD14 gene (T/C at position -159) in Greek patients with CD and UC.METHODS: DNA was obtained from 120 patients with CD,85 with UC and 100 healthy individuals. Genotyping was performed by allele specific PCR or by PCR-RFLP analysis.RESULTS: The 299Gly allele frequency of the TLR4 gene and the T allele and TT genotype frequendes of the CD14 promoter were significantly higher in CD patients only compared to healthy individuals (P = 0.026＜0.05; P = 0.0048＜0.01 and P= 0.047＜0.05 respectively). Concerning the NOD2/CARD15mutations the overall presence in CD patients was significantly higher than that in UC patients or in controls.Additionally, 51.67% of the CD patients were carriers of a TLR4 and/or CD14 polymorphic allele and at least one variant of the NOD2/CARD15, compared to 27% of the UC patients. It should be pointed out that both frequencies significantly increased as compared with the 10% frequency of multiple carriers found in healthy controls. A possible interaction of the NOD2/CARD15 with TLR4 and especially CD14, increased the risk of developing inflammatory bowel disease (IBD).CONCLUSION: Our results indicate that co-existence of a mutation in either the TLR4 or CD14 gene, and in NOD2/CARD15is associated with an increased susceptibility to developing CD compared to UC, and to developing either CD or UC compared to healthy individuals.
文摘Summary: The role of CD80/CD86 and CTLA-4 in the pathogenesis of systemic lupus erythematosus and their clinical significance was investigated. By using RT-PCR technique, the expression of CD80/CD86 and CTLA-4 mRNA in peripheral blood mononuclear cells (PBMC) were semiquantitatively detected in 32 patients with active SLE. The results showed that the percentage of positive CD86 expression in active SLE was increased significantly as compared with normal controls (90.63 % vs 60.00 %, P<0.01). The mean level of CD86 mRNA expression in active SLE group was markedly higher than in the normal controls (0.6410+0.0174 vs 0.4510+0.0402, P<0.001). Compared with normal controls, the percentage of positive CTLA-4 expression and the mean level of CTLA-4 mRNA expression in active SLE group were both increased significantly (both P<0.01). There was no statistical differences in positive rate of CD80 and the average level of CD80 mRNA between the two groups (both P>0.05). It was concluded that the aberrant expression of CD86 and CTLA-4 might play an important role in the activity and development of SLE.
文摘Background: Human immunodeficiency virus and hepatitis B and C viruses are endemic in sub- Saharan African countries including Nigeria. Researchers have studied the burden of co-infection of HIV with hepatitis B and hepatitis C but the risk factors and clinical presentation have not been much addressed especially in children. Methodology: This was a prospective cross sectional study that determined the prevalence, risk factors, clinical features, baseline CD4<sup>+</sup> count, CD4<sup>+</sup> percentage, and alanine aminotransferase (ALT) of newly diagnosed, HAART na?ve HIV co-infection among children who were managed at a Tertiary Hospital in Ilorin, Nigeria. Result: Of the 60 HIV- infected children recruited, 11.7% had HIV co-infection with HBV or HCV. Children with co-infec- tions (mean age 8.43 ± 2.37 years) were significantly older than their HIV mono-infected counterparts (mean age 5.25 ± 3.96 years) (p = 0.011). There was no significant difference between HIV monoinfection and HIV co-infection with respect to gender (p = 0.758), ethnicity (p = 0.707), religion of parents (p = 0.436), family type (p = 0.184), social class (p = 0.535), previous transfusion (p = 0.053), scarification (p = 0.612), female genital mutilation (p = 0.778), and sharing of clippers (p = 0.806). The mean BMI, immunological staging (p = 0.535), baseline ALT (p = 0.940), and mean baseline CD4<sup>+</sup> count (p = 0.928) were comparable. However, the body mass index of HIV co-infec- ted children decreased with age up till age 10 years. Conclusion: There were no risk factors, nor clinical features predictive of co-infection identified in this study. Co-infection did not negatively impact baseline, CD4<sup>+</sup> count and ALT.
文摘Summary： To investigate the expression and significance of CD28 and CTLA4 on T cells in bone marrow of aplastic anemia （AA） mice, in vitro bone marrow mononuclear cells （BMMNCs） were activated through being incubated with PHA （15 μg/mL）. The expression of CD28 and CTLA4 on T cells incubated with or without PHA was detected by two-color flow cytometry. The expression of CD28 and CTLA4 was significantly increased after PHA stimulation. In the AA mice. the expression of CD28 with or without PHA stimulation was both higher than that in the normal mice （both P〈0.01）, but the expression of CTLA4 with or without PHA stimulation showed no significant difference in comparison to that in the normal mice （both P〉0.05）. In the AA mice, there were more activation and activated potential of T cells than the normal, and the abnormal expression of CD28 and CTLA4 may participate in immunological disorder mediated by T cells.
文摘Parasite-specific CD8+ T cells have been shown to transfer protection against nLeishmania major in susceptible BALB/c mice.An epitope-tagged expression library was used to identify the antigen recognized by a protective CD8+ T cells clone. The expression library allowed recombinant proteins made in bacteria to be captured by macrophages for presentation to T cells restricted to major histompatibility complex class n. A conserved 36-kilodalton member of the tryptophanaspartic acid repeat family of proteins was identified that was expressed in both stages of the parasite life cycle. A 24-kilodalton portion of this antigen protected susceptible mice when administered as a vaccine with interleukin-12before injection.
基金This work was supported by grants from the Army Technology Research Program of China(BWS12J051)the National Natural Science Foundation of China(31570873)+1 种基金the Shanghai Committee of Science and Technology(2015QA1404700)We thank Professor Guanhong Song and Prof.Xuetao Cao for their critical review of the manuscript.
文摘The T-cell-mediated immune response is implicated in many clinical hepatic injuries, such as autoimmune hepatitis and acute virus hepatitis. CD24 is widely expressed by different immune cells and plays an important role in the pathogenesis of many autoimmune diseases. However, the role of CD24 in T-cell-mediated liver injury has not been elucidated until now. Here we showed that CD24 deficiency protects mice from concanavalin A (ConA)-induced fulminant liver injury by reducing serum interferon-γ (IFN-γ) levels. CD24 expression by hepatic T cells was markedly increased following ConA challenge. Moreover, decreased IFN-γ production by hepatic CD4^(+) T cells in CD24-deficient mice was detected, which was correlated with downregulated phosphorylation of STAT1 in hepatic tissue. In vitro experiments also supported the conclusion that CD24 deficiency impaired IFN-γ production by CD4^(+) T cells following ConA, CD3/CD28 and phorbol myristate acetate/ionomycin stimulation. Our study suggests that CD24 deficiency confers hepatoprotection by decreasing CD4^(+) T-cell-dependent IFN-γ production in vivo, which suggests that CD24 might be a potential target molecule for reducing clinical hepatitis.
基金Supported by Grants from the Erich und Gertrud Roggenbuck Foundation,Hamburg and the Werner Otto Foundation,Hamburg
文摘AIM:To test the hypothesis that liver cirrhosis is associated with mobilization of hematopoietic progenitor cells. METHODS:Peripheral blood samples from 72 patients with liver cirrhosis of varying etiology were analyzed by flow cytometry.Identified progenitor cell subsets were immunoselected and used for functional assays in vitro. Plasma levels of stromal cell-derived factor-1(SDF-1) were measured using an enzyme linked immunosorbent assay.RESULTS:Progenitor cells with a CD133 + /CD45 + CD14 + phenotype were observed in 61%of th patients.Between 1%and 26%of the peripheral bloo mononuclear cells(MNCs)displayed this phenotype Furthermore,a distinct population of c-kit + progenito cells(between 1%and 38%of the MNCs)could b detected in 91%of the patients.Additionally,18% of the patients showed a population of progenito cells(between 1%and 68%of the MNCs)that wa characterized by expression of breast cancer resistanc protein-1.Further phenotypic analysis disclosed tha the circulating precursors expressed CXC chemokin receptor 4,the receptor for SDF-1.In line with thi finding,elevated plasma levels of SDF-1 were presen in all patients and were found to correlate with th number of mobilized CD133 + progenitor cells.
