Humans ; T-Lymphocytes, Cytotoxic ; immunology ; virology

CD4-Positive T-Lymphocytes ; HIV ; HIV Infections ; virology ; Hepacivirus ; classification ; Hepatitis C ; virology ; Humans ; Liver Transplantation ; Postoperative Period ; Superinfection ; virology

Progressive multifocal leukoencephalopathy (PML) is a rare and lethal central nervous demyelinating disease caused by JC polyomavirus (JCV), particularly in patients with impaired immune system. The variation of JCV plays an important role in the pathogenesis of PML, including the recombination of non-coding regulatory region (NCCR), which is closely related to binding sites of transcription factors and affect the level of gene transcription. Nucleotide mutations in VP1 region determine the antigenicity and receptor specificity of JCV, play an important role in cell adsorption, immune-mediation and pathogenicity. In addition, immune cells are also involved in the pathogenesis of PML. T lymphocytes can recognize virus antigens, clear JCV, which are directly related to the prognosis of PML. B lymphocytes can serve as latent sites of JCV, and participate in viral transmission, replication, and coordination of the expression of transcription factors. This paper summarizes the roles of JCV variation and immune cells in pathogenesis of PML.
B-Lymphocytes ; immunology ; virology ; Capsid Proteins ; genetics ; immunology ; Humans ; JC Virus ; immunology ; Leukoencephalopathy, Progressive Multifocal ; pathology ; virology ; Mutation ; T-Lymphocytes ; immunology ; virology

The influenza A virus (IAV) belongs to the family Influenza Virus and subfamily Orthomyxoviridae. The IAV can cause acute infections of the lower respiratory in human and animals. Recently, many studies have been performed to reveal the lung CD4+ T cells, CD8+ T cells and Tregs via multiple effector and regulatory mechanisms to against IAV. In this paper, we review the state of progress with regards to various strategies of IAV escape from T cell responses, T cells and innate T cells immunity against influenza virus, which will provide a useful reference tool for future related reseach.
Animals ; Humans ; Influenza A virus ; immunology ; physiology ; Lung ; immunology ; virology ; T-Lymphocytes ; immunology

Genotype ; Hepatitis B virus ; genetics ; Hepatitis B, Chronic ; physiopathology ; virology ; Humans ; T-Lymphocytes, Cytotoxic

Hepatitis B virus ; Hepatitis B, Chronic ; immunology ; virology ; Humans ; T-Lymphocytes ; immunology

This study was aimed to explore the method for induction and expansion of EB virus specific cytotoxic T lymphocytes (EBV-CTL) in vitro, and to detect their killing effect. Peripheral blood mononuclear cells (PBMNC) were collected from 6 EBV seropositive healthy donors, and EBV-transformed B lymphoblastoid cells (BLCL)were used as the antigen-presenting cells and antigen stimulant which was irradiated by 40 Gy (60)Co irradiator. The autologous PBMNC and irradiated BLCL were cultured to induce and expand the EBV-CTL, and the immunophenotype was identified by the flow cytometry. The killing effect of the EBV-CTL against the autologous BLCL (autoBLCL), the autologous PHA cultured B lymphoblastoid cells( PHA-BLCL), the allogeneic BLCL (alloBLCL) and the K562 cells were measured with LDH release assay under different effector-to-target ratio. The results showed that the 6 cell lines of EBV-CTL were induced and expanded from the EBV seropositive healthy donors, the overall increase in cell numbers varied from 18.6 to 55.0 times. After 10 stimulations, the specific killing efficiency of the EBV-CTL for the autoBLCL were 59.4%, 43.2% and 29.0% under the effector-to-target ratio of 20: 1, 10: 1 and 5: 1. The nonspecific killing efficiency for the PHA-blast, alloBLCL and K562 cells were 7.1%, 9.4% and 10.3% (P < 0.05) under the 20: 1 ratio; 6.6%, 8.3% and 8.1% (P < 0.05) under 10: 1; 5.4%, 7.3% and 6.3% (P < 0.05) under 5: 1, respectively. It is concluded that the EBV-CTL can be successfully induced and expanded ex vivo for specific killing of HLA matched BLCL and may become a potential treatment for EBV related post-transplant lymphoproliferative disorders.
B-Lymphocytes ; immunology ; Cell Line, Transformed ; Herpesvirus 4, Human ; immunology ; Humans ; K562 Cells ; Leukocytes, Mononuclear ; immunology ; virology ; T-Lymphocytes, Cytotoxic ; cytology ; immunology ; virology

BACKGROUNDThe 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.

METHODSHIV-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.

RESULTSCD4(+) 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.

CONCLUSIONSOne 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.

Adult ; Antigen Presentation ; CD4-Positive T-Lymphocytes ; immunology ; virology ; CD8-Positive T-Lymphocytes ; immunology ; HIV-1 ; immunology ; Humans ; Lymphocyte Activation ; Male ; Virion ; immunology

Central Nervous System Viral Diseases ; complications ; virology ; Child ; Epstein-Barr Virus Infections ; complications ; virology ; Female ; Follow-Up Studies ; Herpesvirus 4, Human ; Humans ; Lymphocytosis ; etiology ; virology ; T-Lymphocytes

The aim of this study was to analyze the clinical features and laboratory findings of adult Epstein-Barr virus associated T/NK cell lymphoproliferative disease (EBV+T/NK-LPD) and to investigate the early diagnosis and prognosis of EBV+T/NK-LPD. The clinical data of 19 adult patients with EBV+T/NK-LPD were retrospectively analyzed. The results indicated that there were 11 males and 8 females. The median age was 32 years (range: 20-70 years). The average duration from onset of symptoms to diagnosis was 3.5 months. The median survival time was 2.5 months. Unkown fever, hepatosplenomegaly, liver dysfunction and interstitial pneumonia were the main clinical features. High levels of β2-MG, LDH, TNF, IL-6 and significantly increased EBV-DNA level (median level > 10(6) copies/ml) were occurred in all the patients. Cytopenia was seen in 18 cases. Morphologically, atypical large granular lymphocytes and hemophagocytosis were common in bone marrow smears. Deletion of CD5 or CD7 were frequently observed in T/NK lymphocytes in bone marrow cells by flow cytometry. Bone marrow biopsy showed atypical lymphocyte interstitial infiltrated in 10 cases, while a few large cells infiltrated in 6 cases. Immunohistochemistry showed the expression of CD3(+)CD56(+) were seen in 2 cases, CD3(+)CD8(+) in 11 cases and CD3(+)CD4(+) in 3 cases. TIA-1 and EBER were positive in all biopsy specimens. Three cases underwent biopsy of lymph nodes showed reactive proliferations of lymphocytes. All the patients died of multiorgan failure. It is concluded that the fever, hepatosplenomegaly are the most common clinical features in adult EBV+T/NK-LPD, the bone marrow infiltration of EBV-infected T/NK lymphocytes and significantly increased EBV-DNA level can be observed in all cases, the clinical outcome of this disease is poor, these clinical and experimental features can be served as a reliable marker for the timely diagnosis of adult EBV+T/NK-LPD.
Adult ; Aged ; Epstein-Barr Virus Infections ; pathology ; Female ; Humans ; Immunophenotyping ; Killer Cells, Natural ; virology ; Lymphoproliferative Disorders ; pathology ; virology ; Male ; Middle Aged ; Retrospective Studies ; T-Lymphocytes ; virology ; Young Adult