Hepatocytes are the primary targets of the hepatitis C virus (HCV). While immunosuppressive roles of HCV core protein have been found in several studies, it remains uncertain whether core protein expressed in hepatocytes rather than in immune cells affects the CD8+ T cell response. In order to transduce genes selectively into hepatocytes, we developed a baculoviral vector system that enabled primary hepatocytes to express a target epitope for CD8+ T cells, derived from ovalbumin (OVA), with or without HCV core protein. Culture of OVA-specific CD8+ T cells with hepatocytes infected with these baculoviral vectors revealed that core protein has no effect on proliferation or apoptosis of CD8+ T cells. Our results suggest that HCV core protein does not exert its suppressive role on the CD8+ T cell immune response through expression in hepatocytes.
Viral Core Proteins/*metabolism ; Ovalbumin/genetics/immunology ; Mice ; Hepatocytes/cytology/*virology ; Green Fluorescent Proteins/genetics ; Genetic Vectors ; Cell Proliferation ; CD8-Positive T-Lymphocytes/*immunology ; Baculoviridae/genetics ; Apoptosis ; Animals

Cytomegalovirus (CMV) infection is a dangerous complication in patients with chronic graft versus host disease (cGVHD). CMV-specific immunity depends on the activity of T cells. This study was aimed to investigate the effect of CMV pp65 gene modified dendritic cells (DCs) on activation of autologous T cells. Lentivirus system was utilized to introduce the CMV full-length pp65 gene into mouse DCs; CpG-DNA was used to induce mature DCs; flow cytometry and immunofluorescence were used to determine the expression of antigen and IFNgamma in T lymphocytes. The results showed that the DCs were infected with lentivirus at a multiplicity of infection (MOI) of 50 with optimal infectious efficiency of 30%-40%; mature DCs expressing pp65 gene could stimulate autologous naive T cells to express CD69 specifically; mature DCs expressing PP65 could stimulate autologous CD4+ or CD8+ T cells to produce IFNgamma. It is concluded that CMV pp65-modified and CpG-DNA-induced mature DCs can activate CMV-specific T lymphocytes in vitro.
Animals ; Antigens, CD ; genetics ; metabolism ; Antigens, Differentiation, T-Lymphocyte ; genetics ; metabolism ; Antigens, Viral ; immunology ; CD4-Positive T-Lymphocytes ; immunology ; CD8-Positive T-Lymphocytes ; immunology ; CpG Islands ; genetics ; Cytomegalovirus ; immunology ; DNA ; genetics ; Dendritic Cells ; cytology ; immunology ; metabolism ; Humans ; Interferon-gamma ; genetics ; metabolism ; Lectins, C-Type ; Lentivirus ; genetics ; metabolism ; Mice ; Phosphoproteins ; genetics ; metabolism ; Viral Matrix Proteins ; genetics ; metabolism

Blockade of signal 1 or 2 for T-cell activation by the use of anti-CD45RB and anti-CD154 monoclonal antibodies (mAb) (two-signal blockade) has been proven effective in preventing or delaying graft rejection. However, the mechanisms of its immunomodulatory effects are clearly unknown and the present studies were performed to determine how the two-signal blockade modulate allogeneic immune responses, especially T-cell mediated cellular immunity, in a murine skin allograft model. We now report on the profound inhibition of alloreactive T cells by two-signal blockade via CD4-dependent mechanisms. C57BL/6 mice of BALB/c skin allograft were treated with anti-CD45RB, anti-CD154, CTLA4-Ig, or their combinations. For depletion of CD4 or CD8 T cells, the recipients received CD4-depleting or CD8-depleting mAb. We confirmed that survival of skin allograft was markedly prolongated in the two-signal blockade-treated group. In depletion study, anti-CD45RB, anti-CD154 and CD4-depleting mAb-treated group showed acute rejection of skin allograft in contrast to CD8-depleting group treated with the two-signal blockade. In the group treated with the two-signal blockade, the proportions of CD4+CD45RB(low)and CD8+CTLA-4 regulatory T cells were increased while effector CD8+ T cells, including IFN-gamma-secreting and CD8+CD62L(low)T cells, were decreased when compared with non-treated group. In contrast, the CD4-depleted group treated with the two-signal blockade resulted in recovery from immunoregulatory effects of two-signal blockade. In addition, results of IL-4 and IL-10 production were also showed CD4-dependence. Therefore, the two-signal blockade is accompanied by CD4-dependent mechanisms in allogeneic skin transplantation.
Transplantation, Homologous ; T-Lymphocytes, Regulatory/cytology/immunology ; Skin Transplantation/*immunology ; Signal Transduction/drug effects/immunology ; Mice, Inbred C57BL ; Mice, Inbred BALB C ; Mice ; Male ; Lymphocyte Depletion ; Lymphocyte Activation/immunology ; Interleukin-4/biosynthesis ; Interleukin-10/biosynthesis ; Graft Rejection/*immunology/prevention & control ; Flow Cytometry ; Cytotoxicity, Immunologic/immunology ; CD8-Positive T-Lymphocytes/cytology/immunology/metabolism ; CD40 Ligand/*immunology ; CD4-Positive T-Lymphocytes/cytology/immunology/metabolism ; Antigens, CD45/*immunology ; Antigens, CD4/*immunology ; Antibodies, Monoclonal/administration & dosage/*pharmacology ; Antibodies, Blocking/administration & dosage/pharmacology ; Animals

BACKGROUNDIt has been reported that CD8(+) regulatory cells could be induced upon oral tolerance. The purpose of this study was to investigate the changes of CD8α(+) T cells in dextran sulfate sodium (DSS)-induced colitis mice pretreated by oral immune regulation.

METHODSThe effects of five low oral doses of colitis-extracted proteins (CEP) on colitis were evaluated by clinical manifestation and histological lesions. The percentages of CD8α(+) T cells gating on CD3(+) T cells were evaluated in the gut-associated lymphoid tissues (GALT) and the spleens by flow cytometry. Differences between the two groups were compared by Student's t test or Mann-Whitney U test.

RESULTSCompared to bovine serum albumin (BSA)-fed control mice, administration of CEP resulted in marked alleviation of colitis. The proportion of CD8α(+) T cells, not only in intraepithelial lymphocytes (IELs) and lamina propria lymphocytes (LPLs) of the large intestine (LI) but also in spleen from CEP-fed colitis mice, was significantly higher than that from BSA-fed colitis mice (LI-IELs: (71.5 ± 5.4)% vs. (60.1 ± 4.3)%, P < 0.01; LI-LPLs: (60.7 ± 5.2)% vs. (51.9 ± 4.7)%, P < 0.01; spleen: (24.1 ± 3.6)% vs. (20.3 ± 4.1)%, P < 0.05; n = 8). Mucosal repair in repair-period mice five days after termination of DSS treatment was also accompanied by an increase of CD8α(+) T cells in large intestinal mucosal lymphocytes (LI-IELs: (72.1 ± 3.7)% vs. (61.5 ± 4.5)%, P < 0.01; LI-LPLs: (62.1 ± 5.7)% vs. (52.7 ± 3.6)%, P < 0.01; n = 8). The proportion of CD3(+) T cells increased in Peyer's patches (PPs) and decreased in mesenteric lymph nodes (MLNs) from colitis mice compared to untreated mice, whereas the change pattern of CD3(+) T cells in PPs and MLNs from CEP-fed colitis mice was just on the contrary.

CONCLUSIONImprovement of DSS-induced colitis resulted from oral immune regulation is associated with an increase in CD8α(+) T cells in spleen and large intestinal mucosa.

Administration, Oral ; Animals ; CD8-Positive T-Lymphocytes ; metabolism ; Colitis ; chemically induced ; complications ; Dextran Sulfate ; toxicity ; Flow Cytometry ; Lymphocytes ; cytology ; metabolism ; Male ; Mice ; Mice, Inbred BALB C ; Proteins ; administration & dosage ; immunology ; Spleen ; cytology ; metabolism

OBJECTIVETo identify autoepitopes of E2 subunit of pyruvate dehydrogenase complex (PDC-E2) specific CD8+ CTL in primary biliary cirrhosis (PBC) patients.

METHODSAn online database SYFPEITHI was applied to predict HLA-A*0201 restricted epitopes which located in PDC-E2 30-50 aa and 150-190 aa where B-cell epitopes clustered with CD4+ T-cell epitopes. T2 cell line reconstitution and stabilization assay, induction of specific CTL lines from peripheral blood mononuclear cells (PBMCs) of patients with PBC and cytotoxicity of peptides-induced CTL were performed to screen the epitopes from those candidates.

RESULTSFive potential epitopes were predicted by database. Of the 5 candidates, two peptides 159-167 aa and 165-174 aa, with highly binding activity to HLA-A*0201 molecules, could stimulate PBMCs from most HLA-A*0201 positive PBC patients to proliferate and peptide-induced CTL lines showed specific cytotoxicity.

CONCLUSIONPeptides of KLSEGDLLA (159-167 aa) and LLAEIETDKA (165-174 aa) in the inner lipoyl domain of PDC-E2 are HLA-A*0201 restricted CD8+ CTL immunodominant epitopes in PBC.

Antibody-Producing Cells ; cytology ; Autoantigens ; immunology ; Autoimmunity ; CD8-Positive T-Lymphocytes ; cytology ; immunology ; metabolism ; Cell Line ; Dihydrolipoyllysine-Residue Acetyltransferase ; Epitope Mapping ; Epitopes, T-Lymphocyte ; immunology ; HLA-A Antigens ; immunology ; HLA-A2 Antigen ; Humans ; Liver Cirrhosis, Biliary ; enzymology ; genetics ; immunology ; Phenotype ; Protein Binding ; Pyruvate Dehydrogenase Complex ; genetics ; immunology ; metabolism ; T-Lymphocytes, Cytotoxic ; immunology

Heat-shock protein (Hsp) 70 potentiates specific immune responses to some antigenic peptides fused to it. Here, the prokaryotic plasmids harboring the envelope glycoprotein E0 gene of classical swine fever virus (CSFV) and/or the Hsp70 gene of Haemophilus parasuis were constructed and expressed in Escherichia coli Rosseta 2(R2). The fusion proteins were then purified. Groups of Balb/c mice were immunized with these fusion proteins, respectively, and sera collected 7 days after the third immunization. Immune effects were determined via an enzyme-linked immunosorbent assay and flow cytometric analyses. E0-Hsp70 fusion protein and E0+Hsp70 mixture significantly improved the titer of E-specific antibody, levels of CD4+ and CD8+ T cells, and release of interferon-γ. These findings suggested that Hsp70 can significantly enhance the immune effects of the envelope glycoprotein E0 of CSFV, thereby laying the foundation of further application in pigs.
Animals ; Antibodies, Viral ; blood ; CD4-Positive T-Lymphocytes ; cytology ; immunology ; CD8-Positive T-Lymphocytes ; cytology ; immunology ; Cell Proliferation ; Classical swine fever virus ; genetics ; Female ; HSP70 Heat-Shock Proteins ; genetics ; immunology ; Haemophilus parasuis ; genetics ; Immunization ; Interferon-gamma ; metabolism ; Mice ; Mice, Inbred BALB C ; Plasmids ; genetics ; Recombinant Fusion Proteins ; genetics ; immunology ; Viral Envelope Proteins ; genetics

This study was aimed to eveluate the role of CCR5 on donor cells in recipient models received intensive conditioning, so as provide the scientific evidence for clinical application of allo-HSCT. Lethally irradiated BALB/c mice received allogeneic bone marrow transplants from C57BL/6 mice. Mice divided into 4 groups according to receiving variant donor cells: B6 CCR5 KO group, receiving C57BL/6 CCR5(-/-) mice bone marrow cells and splenocytes; B6 WT BMC group, receiving C57BL/6 mice bone marrow cells and splenocytes; B6 CCR5 KO BMC group, receiving C57BL/6 CCR5(-/-) bone marrow cells alone; B6 WT BMC group, receiving C57BL/6 mice bone marrow cells alone. The result showed that compared to B6 WT BMC group, B6 CCR5 KO group succumbed to acute GVHD at an accelerated rate. Donor CD8(+) T cells expanded to a significantly greater extent in recipients of CCR5 KO, compared with B6 WT control cells. T cells recovered from recipients of CCR5 KO cells produced more IFN-gamma and TNF-alpha and proliferated to a T-cell at a significantly higher level than T cells from recipients of WT cells, indicating that CCR5 plays a role in downregualting donor alloreative CD8(+) T-cells expansion. Histological assessment of the mice indicated pathological lesions in the kidneys and a greater degree of liver pathological changes in mice that received CCR5 KO donor grafts. It is concluded that the knock-out of CCR5 on donor cells results in increase of GVHD and donor CD8(+) T cell expansion, as well as hepatic and renal lesions in allo-HSCT, which indicates that CCR5 is very important in allo-BMT.
Animals ; Bone Marrow Transplantation ; adverse effects ; CD8-Positive T-Lymphocytes ; cytology ; immunology ; transplantation ; Female ; Graft vs Host Disease ; metabolism ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Receptors, CCR5 ; genetics ; physiology

OBJECTIVETo clone IgHV genes from childhood B-ALL cells and identify CTL epitopes deduced from IgHV gene.

METHODSSeven IgHV gene families were respectively amplified by PCR and directly sequenced for 37 childhood B-ALL cases. Bioinformatics were applied for analyzing characteristics of sequences available and predicting HLA-A*0201 molecule-binding nonapeptides derived from IgHV. The predicted nonapeptide QLVQSGAEV was synthesized and its binding affinity to T2 cells determined. CD8+ T cells from a healthy HLA-A*0201+ donor peripheral blood were stimulated repeatedly with QLVQSGAEV-loaded antigen presenting cells.

RESULTSIgHV gene rearrangements were identified in 37 B-ALL. Forty IgHV gene sequences available preferentially utilized V(H)4-59 and V(H)4-34 gene segments. Increased frequency (15.4%) of D7-27 in B-ALL IgHV was found compared to that reported for adult PBLs (P = 0.02); 20.0% DJ(H) junctions in B-ALL lacked non-encoding nucleotides, a frequency higher than that reported for adult PBLs (P = 0.02). 17.5% B-ALL IgHV contained < 2% replacement mutations. Forty B-ALL IgHV sequences acquired 12 high HLA-A*0201-binding nonapeptides, 10 (83.0%) peptides were located in frame region (FR)1 and 3. The synthesized peptide QLVQSGAEV up-regulated HLA-A*0201 expression 1.63 fold on the surface of T2 cells. The frequency of QLVQSGAEV-specific CD8+ T cells in a healthy HLA-A*0201+ donor peripheral blood increased from 1.6% and 82.6% after two-round and 3-round stimulations, respectively.

CONCLUSIONIgHV genes in childhood B-ALL are of germline characteristics. Their heavy chain framework regions contain HLA-A*0201-binding nonapeptides. These peptides are capable of inducing specific CD8+ T cells to activate and proliferate.

Adolescent ; Burkitt Lymphoma ; genetics ; immunology ; CD8-Positive T-Lymphocytes ; cytology ; immunology ; Cell Proliferation ; Child ; Child, Preschool ; Epitopes, T-Lymphocyte ; immunology ; Gene Rearrangement ; HLA-A Antigens ; immunology ; metabolism ; HLA-A2 Antigen ; Humans ; Immunoglobulin Heavy Chains ; genetics ; immunology ; Immunoglobulin Variable Region ; genetics ; immunology ; Infant ; Oligopeptides ; immunology

BACKGROUNDAspergillosis infection is common in the patients with insufficient immunity. The role of mammalian target of rapamycin (mTOR), T-box expressed in T-cells (T-bet), and eomesodermin (EOMES) in mediating T lymphocytes differentiation in response to Aspergillus fumigatus infection in immunocompromised rats was investigated in this study.

METHODSInvasive pulmonary aspergillosis (IPA) of immunosuppressive twenty male rats were established and sacrificed at 24 h (n = 5), 48 h (n = 5), 72 h (n = 5), and 96 h (n = 5) after A. fumigatus infection. In addition, control (n = 5), cyclophosphamide (CTX) (n = 5), and aspergillosis (n = 5) group were also established the tissues and pathology of lung tissue was examined by hematoxylin and eosin staining. CD8+ T-cells was sorted by flow cytometry. Serum mTOR, S6K, T-bet, and EOMES were quantified by enzyme-linked immunosorbent assay.

RESULTSHistology of lung tissue indicated severe lung tissue injury including infiltration of inflammatory cells, alveolar wall damage or degradation, blood congestion, and hemorrhage in the CTX, IPA, and CTX + IPA rats. Hyphae were seen in the IPA, and CTX + IPA groups. The proportion of CD8+ T-cells was significantly increased in the animals of CTX + IPA. Memory CD8+ T-cells was significantly increased in early stage (24 h and 48 h, P < 0.001), but decreased in the late phase of fungal infection (72 h and 96 h) in the animals of CTX + IPA. In addition, at early stage of fungal infection (24 h and 48 h), serum mTOR (P < 0.001), S6K (P < 0.001), and T-bet (P < 0.05) was significantly higher, while EOMES was significantly lower (P < 0.001), in CTX + IPA group than that in control, CTX alone or IPA alone group. Conversely, serum mTOR, S6K, T-bet, and EOMES showed opposite changed in the late stage (72 h and 96 h). Pearson's correlation analysis indicated that mTOR and S6K were significantly correlated with T-bet (r = 0.901 and 0.91, respectively, P < 0.001), but negatively and significantly correlated with EOMES (r = -0.758 and -0.751, respectively, P < 0.001).

CONCLUSIONSmTOR may regulate transcription factors of EOMES and T-bet, and by which mechanism, it may modulate lymphocytes differentiation in animals with immune suppression and fungal infection.

Animals ; CD8-Positive T-Lymphocytes ; cytology ; metabolism ; Cell Differentiation ; genetics ; physiology ; Invasive Pulmonary Aspergillosis ; metabolism ; pathology ; Lung ; metabolism ; pathology ; Lymphocytes ; cytology ; immunology ; Male ; Rats ; Rats, Wistar ; T-Box Domain Proteins ; genetics ; metabolism ; TOR Serine-Threonine Kinases ; genetics ; metabolism ; Tissue Culture Techniques

OBJECTIVETo investigate the effect of murine mesenchymal stem cells (mMSC) on immunoproliferative response of spleen cells.

METHODSMitogen (Con A, 20 microg/ml) or irradiated (20 Gy) allogeneic spleen cells (from BALB/c or C57BL/6 mouse depending on the responder cells) were used as stimulators. Proliferations of the responder cells were determined with MTT on day 3 after culture at 37 degrees C, 5% CO2 humidified atmosphere. The ratios of CD4+/CD8+ and CD4+CD25+ cells were analyzed with FACS assay, and the levels of cytokines in supernatants with ELISA.

RESULTS1) mMSC inhibited the response of both syngeneic and allogeneic splenic cells to ConA. At the ratio of mMSC to splenic cells being 1: 1, the inhibition rate reached 84.21%. With the ratio decreasing, the inhibition rate decreased. 2) mMSC inhibited the response of both syngeneic and allogeneic splenic cells to alloantigen. When the ratio of mMSC to responder cells was 1: 10, the inhibition rate was as high as 88.07%. 3) mMSC could increase the ratio of CD4+/ CD8+ T cells and the percentage of CD4+ CD25+ cells in splenic cells. These abilities were in a dose-dependent manner and non-MHC antigen restricted. 4) mMSC decreased interleukin (IL) -2, interferon (IFN)-gamma, while increased TGF-beta1 and IL-4 in the co-culture system.

CONCLUSIONmMSC can suppress proliferative response of splenic cells to mitogen and alloantigen, increase the ratio of CD4+/CD8+ and the proportion of CD4+ CD25+ in T cells, decrease the secretion of proinflammatory cytokines and increase the anti inflammatory cytokines in a dose-dependent and non-MHC antigen restricted manner.

Animals ; Bone Marrow Cells ; immunology ; CD4-CD8 Ratio ; CD4-Positive T-Lymphocytes ; immunology ; Cells, Cultured ; Interferon-gamma ; metabolism ; Interleukin-2 ; metabolism ; Interleukin-4 ; metabolism ; Male ; Mesenchymal Stromal Cells ; immunology ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Spleen ; cytology ; immunology ; metabolism ; Transforming Growth Factor beta ; metabolism