title: Mycobacterium tuberculosis-specific CD8+ T cell recall in convalescing TB subjects with HIV co-infection.
abstract: Memory T cell populations recover following phase I chemotherapy for tuberculosis (TB) and augment the effectiveness of antibiotics during the continuation phase of treatment. For those with human immunodeficiency virus (HIV), the CD8(+)T cells may have an especially important role in host defense to Mycobacterium tuberculosis (M.tb) as CD4(+)T cell function and/or numbers decline. Here we performed a preliminary study to investigate the impact of HIV infection status on CD8(+)T cell effector function during the convalescent TB period. Peripheral blood samples from convalescent HIV(+) and HIV(-) TB subjects were used to determine CD4(+)T cell count and monitor antigen-specific CD8(+) T cell activation of effector function (lymphoproliferation, IFN-γ, granulysin) in response to M.tb antigen. Our preliminary results suggest that HIV co-infection is associated with moderate suppression of the M.tb-specific memory CD8(+)T cell compartment in many subjects convalescent for TB. Interestingly, highly activated CD8(+)T cells were observed in recall experiments using peripheral blood from several HIV+ subjects that had low (<200 cells/mm(3)) CD4(+)T cell counts. Further investigation may provide important information for development of novel approaches to target M.tb-specific CD8(+)T cell memory to protect against TB in HIV-endemic regions.
authors.affiliation: Kenya Medical Research Institute, Centre for Respiratory Diseases Research, Nairobi, Kenya.
authors.forename: Asiko
authors.initials: A
authors.lastname: Ongaya
authors.affiliation: Departments of Microbiology and Immunology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, USA.
authors.forename: Matthew B
authors.initials: MB
authors.lastname: Huante
authors.affiliation: Kenya Medical Research Institute, Centre for Respiratory Diseases Research, Nairobi, Kenya.
authors.forename: Paul
authors.initials: P
authors.lastname: Mwangi
authors.affiliation: Department of Internal Medicine, Division of Infectious Diseases, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, USA.
authors.forename: Philip H
authors.initials: PH
authors.lastname: Keiser
authors.affiliation: Kenya Medical Research Institute, Centre for Respiratory Diseases Research, Nairobi, Kenya.
authors.forename: Evans
authors.initials: E
authors.lastname: Amukoye
authors.affiliation: Departments of Microbiology and Immunology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, USA; Department of Pathology, Institute for Human Infections and Immunity, Center for Tropical Diseases, and Sealy Center for Vaccine Development, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, USA. Electronic address: jjendsle@utmb.edu.
authors.forename: Janice J
authors.initials: JJ
authors.lastname: Endsley
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000276:immunology*; D056704:Adaptive Immunity; D000328:Adult; D000911:Antibodies, Monoclonal / Q000276:immunology; D000942:Antigens, Bacterial / Q000276:immunology; D018791:CD4 Lymphocyte Count; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D060085:Coinfection / Q000276:immunology* / Q000473:pathology; D003289:Convalescence; D005260:Female; D005434:Flow Cytometry; D015658:HIV Infections / Q000276:immunology* / Q000473:pathology; D054884:Host-Pathogen Interactions; D006801:Humans; D007111:Immunity, Cellular; D007630:Kenya; D008213:Lymphocyte Activation / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000276:immunology / Q000502:physiology*; D014376:Tuberculosis / Q000276:immunology* / Q000473:pathology
chemical_list: D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial