Failure to control growth of mycobacteria in blood from children infected with human immunodeficiency virus and its relationship to T cell function.
The mechanisms of protective immunity to tuberculosis remain poorly understood in humans. A whole-blood infection model that employs a luminescent readout was used to analyze the role of T cells in control of mycobacterial infection. Control of mycobacterial growth in blood from healthy tuberculin-positive individuals was shown to be mediated predominantly by CD4(+) T cells. Comparison of age-matched cohorts of human immunodeficiency virus (HIV)-infected and -uninfected children from South Africa demonstrated an association between low CD4 cell counts, low interferon (IFN)-gamma production, and impaired ability to regulate growth of Mycobacterium bovis bacille Calmette-Guérin in blood from HIV-infected children. Impaired control of infection was not reconstituted by the addition of exogenous IFN-gamma. The whole-blood assay provides an important tool for monitoring and dissecting of human immune responses to mycobacterial infection.
School of Child and Adolescent Health, Red Cross Children's Hospital, University of Cape Town, Cape Town, Republic of South Africa.
Gwen N
GN
Tena
Douglas B
DB
Young
Brian
B
Eley
Howard
H
Henderson
Mark P
MP
Nicol
Mike
M
Levin
Beate
B
Kampmann
D017088:AIDS-Related Opportunistic Infections / Q000097:blood / Q000150:complications / Q000276:immunology / Q000382:microbiology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006678:HIV / Q000502:physiology*; D015658:HIV Infections / Q000150:complications / Q000276:immunology* / Q000382:microbiology* / Q000821:virology; D006801:Humans; D007223:Infant; D008297:Male; D009169:Mycobacterium tuberculosis / Q000276:immunology / Q000502:physiology*; D014376:Tuberculosis / Q000097:blood / Q000150:complications* / Q000276:immunology* / Q000382:microbiology