ABSTRACT
As the Bacillus Calmette-Guérin (BCG) vaccine does not confer long-lasting protection against lung Mycobacterium tuberculosis infection, the development of more efficient vaccines is greatly needed. Here, we used mycobacterial low-molecular weight proteins of the 6-kDa Early Secreted Antigenic Target (ESAT-6) protein family (ESX) antigens for the evaluation of a novel vaccine delivery strategy that enables versatile in vivo targeting of antigens into specialized dendritic cell (DC) subsets. ESX antigens were genetically fused to the tetramerizing core of streptavidin (SA) to form high-affinity complexes with biotin (biot)-conjugated antibodies recognizing DC surface receptors. When directed through the CD11b or CD11c ß2-integrins or diverse C-type lectins, the ESX-SA:biot-antibody complexes were efficiently captured and presented on major histocompatibility complex molecules of DCs to specific T-cell receptors. Robust ESX-specific T-cell responses were induced by immunization with as little as several picomoles of ESX-SA targeted to DC subsets. Moreover, directing of TB10.4-SA to airway CD205(+) cells enabled the induction of mucosal T-cell responses and provided significant protection against virulent M. tuberculosis.
Subject(s)
Antigens, Bacterial/immunology , Bacterial Proteins/immunology , Dendritic Cells/immunology , Mycobacterium tuberculosis/immunology , Tuberculosis Vaccines/immunology , Tuberculosis, Pulmonary/prevention & control , Animals , Antibodies, Monoclonal/genetics , Antibodies, Monoclonal/immunology , Antigen Presentation , Antigens, CD/metabolism , CD11b Antigen/immunology , CD11c Antigen/immunology , CD18 Antigens/immunology , Cells, Cultured , Female , Humans , Immunity, Active , Lectins, C-Type/metabolism , Lymphocyte Activation , Mice , Mice, Inbred BALB C , Mice, Inbred C3H , Mice, Inbred C57BL , Minor Histocompatibility Antigens , Receptors, Cell Surface/metabolism , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/immunology , Respiratory System/pathology , T-Lymphocytes/immunologyABSTRACT
We have previously shown correction of X-linked severe combined immunodeficiency [SCID-X1, also known as gamma chain (gamma(c)) deficiency] in 9 out of 10 patients by retrovirus-mediated gamma(c) gene transfer into autologous CD34 bone marrow cells. However, almost 3 years after gene therapy, uncontrolled exponential clonal proliferation of mature T cells (with gammadelta+ or alphabeta+ T cell receptors) has occurred in the two youngest patients. Both patients' clones showed retrovirus vector integration in proximity to the LMO2 proto-oncogene promoter, leading to aberrant transcription and expression of LMO2. Thus, retrovirus vector insertion can trigger deregulated premalignant cell proliferation with unexpected frequency, most likely driven by retrovirus enhancer activity on the LMO2 gene promoter.
