Cytotoxic mediators in paradoxical HIV-tuberculosis immune reconstitution inflammatory syndrome.

Abstract

Tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) frequently complicates combined antiretroviral therapy and antituberculosis therapy in HIV-1-coinfected tuberculosis patients. The immunopathological mechanisms underlying TB-IRIS are incompletely defined, and improved understanding is required to derive new treatments and to reduce associated morbidity and mortality. We performed longitudinal and cross-sectional analyses of human PBMCs from paradoxical TB-IRIS patients and non-IRIS controls (HIV-TB-coinfected patients commencing antiretroviral therapy who did not develop TB-IRIS). Freshly isolated PBMC stimulated with heat-killed Mycobacterium tuberculosis H37Rv (hkH37Rv) were used for IFN-γ ELISPOT and RNA extraction. Stored RNA was used for microarray and RT-PCR, whereas corresponding stored culture supernatants were used for ELISA. Stored PBMC were used for perforin and granzyme B ELISPOT and flow cytometry. There were significantly increased IFN-γ responses to hkH37Rv in TB-IRIS, compared with non-IRIS PBMC (p = 0.035). Microarray analysis of hkH37Rv-stimulated PBMC indicated that perforin 1 was the most significantly upregulated gene, with granzyme B among the top five (log2 fold difference 3.587 and 2.828, respectively), in TB-IRIS. Downstream experiments using RT-PCR, ELISA, and ELISPOT confirmed the increased expression and secretion of perforin and granzyme B. Moreover, granzyme B secretion reduced in PBMC from TB-IRIS patients during corticosteroid treatment. Invariant NKT cell (CD3(+)Vα24(+)) proportions were higher in TB-IRIS patients (p = 0.004) and were a source of perforin. Our data implicate the granule exocytosis pathway in TB-IRIS pathophysiology. Further understanding of the immunopathogenesis of this condition will facilitate development of specific diagnostic and improved therapeutic options.

• Authors: Katalin A Wilkinson, Naomi F Walker, Graeme Meintjes, Armin Deffur, Mark P Nicol, Keira H Skolimowska, Kerryn Matthews, Rebecca Tadokera, Ronnett Seldon, Gary Maartens, Molebogeng X Rangaka, Gurdyal S Besra, Robert J Wilkinson
• Journal: Journal of immunology (Baltimore, Md. : 1950) (J Immunol) Vol. 194 Issue 4 Pg. 1748-54 (Feb 15 2015) ISSN: 1550-6606 [Electronic] United States
• PMID: 25589068 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2015 The Authors.

Chemical References

• Perforin
• Interferon-gamma
• Granzymes

Topics

• Adult
• Coinfection
• Cross-Sectional Studies
• Enzyme-Linked Immunosorbent Assay
• Female
• Flow Cytometry
• Granzymes (biosynthesis, immunology)
• HIV Infections (complications, immunology)
• Humans
• Immune Reconstitution Inflammatory Syndrome (etiology, immunology)
• Interferon-gamma (biosynthesis, immunology)
• Leukocytes, Mononuclear (immunology)
• Longitudinal Studies
• Male
• Oligonucleotide Array Sequence Analysis
• Perforin (biosynthesis, immunology)
• Real-Time Polymerase Chain Reaction
• Tuberculosis (complications, immunology)