High throughput functional microdissection of pathogen-specific T-cell immunity using antigen and lymphocyte arrays.

The analysis of the human T-cell response specific for relevant pathogens is useful for diagnostic purposes and for research. Several methods enumerate antigen specific T-cells and measure their functions. Since screening of numerous antigens from pathogens is often needed to evaluate immunocompetence, lymphocytes, labor and cost are limiting factors.

A sealed and unbreached system for purification, stimulation, and expansion of cytomegalovirus-specific human CD4 and CD8 T lymphocytes.

Background: Recent clinical trials have demonstrated the efficacy of adoptive cellular therapy with virus-specific lymphocytes in patients with defective cellular immune responses. Immunoreconstitution has become a challenge for cellular immunology and for transfusion medicine. In fact, both expertises are required to provide effective and safe cellular products.

Human bone marrow stromal cells hamper specific interactions of CD4 and CD8 T lymphocytes with antigen-presenting cells.

Bone marrow stromal cells (BMSCs) may inhibit T-cell functions in vitro and thus have been proposed as immunoregulators to control in vivo graft-versus-host disease (GVHD) in haploidentical hemopoietic stem cell transplants. To better investigate this phenomenon, we used a defined experimental system in which responding T cells are antigen-specific and devoid of alloreactivity against BMSC from a different subject. Thus, we established antigen-specific human CD4 and CD8 T-cell lines as the readout system.

Helper function of cytolytic lymphocytes: switching roles in the immune response.

T helper (Th) cells and cytolytic T lymphocytes (CTL) play defined roles in the cellular immune response. This distinction wavered when Th lymphocytes were shown to kill antigen-presenting cells displaying the relevant antigen. Here we demonstrate that also the opposite can be true: CTL can exert helper functions.

Human naive CD4 T-cell clones specific for HIV envelope persist for years in vivo in the absence of antigenic challenge.

To study the persistence of HIV-specific human naive CD4-lymphocytes in vivo in the absence of antigenic stimulation, we identified 2 HIV-seronegative low-risk subjects carrying CD4-cells specific for gp120 that could be expanded in vitro. CD4 T-cell lines specific for gp120 were generated by stimulation cycles with antigen-pulsed antigen-presenting cells. Clonal analysis was performed by spectratyping and by sequencing of the CDR3 regions of the BV and AV-T-cell receptor (TCR) genes.

Generation of cytomegalovirus (CMV)-specific CD4 T cell lines devoid of alloreactivity, by use of a mixture of CMV-phosphoprotein 65 peptides for reconstitution of the T helper repertoire.

Background: CD8 cells specific for cytomegalovirus (CMV) provide valuable support in immunocompromised patients. Recent studies have focused on the generation of cytotoxic T lymphocyte (CTL) lines by use of new biotechnological techniques. Yet CD4 cells have been neglected, even though they contribute to the persistence of adoptively transferred CTLs.

Recognition of CMV pp65 protein antigen by human CD4 T-cell lines induced with an immunodominant peptide pool.

Cellular immunity against cytomegalovirus (CMV) is essential for recovery from infection and control of viral latency. In immunocompromised hosts, this balance between CMV and cellular immunity is lost. Accordingly, restoration of the CD8 compartment specific for CMV is beneficial for immunocompromised patients.

Identification of new Th peptides from the cytomegalovirus protein pp65 to design a peptide library for generation of CD4 T cell lines for cellular immunoreconstitution.

CD8 and CD4 lymphocytes control cytomegalovirus (CMV) infection in immunocompetent individuals, while patients with defective cellular immunity are prone to endogenous reactivation of latent CMV or, like seronegative subjects, prone to primary infection. Administration of CMV-specific CD8 lymphocytes was beneficial for immunocompromised hemopoietic stem cell (HSC) graft recipients. Since CD4 cells contribute to expansion of cytotoxic T lymphocytes (CTL), we defined new T(h) peptides on the immunodominant protein pp65 recognized by CD4 cells from HLA-typed subjects, in the perspective of complementing CTL administration with CMV-specific T(h) cells.