Send to:

Choose Destination
See comment in PubMed Commons below
Immunology. 2012 May;136(1):96-102. doi: 10.1111/j.1365-2567.2012.03563.x.

Lower numbers of natural killer T cells in HIV-1 and Mycobacterium leprae co-infected patients.

Author information

  • 1Division of Clinical Immunology and Allergy, University of São Paulo, São Paulo, Brazil.


Natural killer T (NKT) cells are a heterogeneous population of lymphocytes that recognize antigens presented by CD1d and have attracted attention because of their potential role linking innate and adaptive immune responses. Peripheral NKT cells display a memory-activated phenotype and can rapidly secrete large amounts of pro-inflammatory cytokines upon antigenic activation. In this study, we evaluated NKT cells in the context of patients co-infected with HIV-1 and Mycobacterium leprae. The volunteers were enrolled into four groups: 22 healthy controls, 23 HIV-1-infected patients, 20 patients with leprosy and 17 patients with leprosy and HIV-1-infection. Flow cytometry and ELISPOT assays were performed on peripheral blood mononuclear cells. We demonstrated that patients co-infected with HIV-1 and M. leprae have significantly lower NKT cell frequencies [median 0.022%, interquartile range (IQR): 0.007-0.051] in the peripheral blood when compared with healthy subjects (median 0.077%, IQR: 0.032-0.405, P < 0.01) or HIV-1 mono-infected patients (median 0.072%, IQR: 0.030-0.160, P < 0.05). Also, more NKT cells from co-infected patients secreted interferon-γ after stimulation with DimerX, when compared with leprosy mono-infected patients (P = 0.05). These results suggest that NKT cells are decreased in frequency in HIV-1 and M. leprae co-infected patients compared with HIV-1 mono-infected patients alone, but are at a more activated state. Innate immunity in human subjects is strongly influenced by their spectrum of chronic infections, and in HIV-1-infected subjects, a concurrent mycobacterial infection probably hyper-activates and lowers circulating NKT cell numbers.

© 2012 The Authors. Immunology © 2012 Blackwell Publishing Ltd.

[PubMed - indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Wiley Icon for PubMed Central
    Loading ...
    Write to the Help Desk