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Year : 2012  |  Volume : 30  |  Issue : 3  |  Page : 323--331

T-cell recognition of iron-regulated culture filtrate proteins of Mycobacterium tuberculosis in tuberculosis patients and endemic normal controls

S Duggirala1, K Venu2, K Subhakar2, M Sritharan1 
1 Department of Animal Sciences, University of Hyderabad - 500 046, Andhra Pradesh, India
2 Government General Chest Hospital, Hyderabad -500 018, Andhra, Pradesh, India

Correspondence Address:
M Sritharan
Department of Animal Sciences, University of Hyderabad - 500 046, Andhra Pradesh
India

Background: Culture filtrate proteins (CFPs) of Mycobacterium tuberculosis are potential vaccine candidates. Objective: The aim was to study the influence of iron levels on CFPs and assess the immuno-protective potential of defined antigenic fractions from high (8 μg Fe/mL) and low iron (0.02 μg Fe / mL) cultures of M. tuberculosis. Materials and Methods: The CFPs of M. tuberculosis from high (CFP-high) and low (CFP-low) iron conditions were first compared to identify iron-regulated proteins and then fractionated to obtain ten antigen pools (CF-Ags H1- H5 and L1-L5) that were used to assess the immune response of TB patients and normal healthy controls. Results: Iron limitation resulted in the up-regulation of two novel iron-regulated low-molecular-weight proteins Irp-1 (in CF-Ag L4) and Irp-2 (in CF-Ag L5) and repression of two ESAT proteins (identified with monoclonal antibody HYB 76.8). The median stimulation indices (SIs) against most of the CF-Ags were high in pulmonary TB patients. The CF-Ags L1 and L2 showed statistically significant SI (P values of 0.0027 and 0.0029 respectively); the % case recognition was high with these antigens as well as with L4 ( P = 0.0275). IFN-γ in response to these CF-Ags was significantly high in the endemic normals; maximal expression was seen with CF-Ag L5 (median value of 233 pg mL -1 ) that was higher than the corresponding H5 (140 pg mL -1 ) and H3 and L3 (205 and 206 pg mL -1 respectively). Conclusions: CF-Ags L5, H3 and L3 showed immuno-protective potential in this geographical location.

How to cite this article:
Duggirala S, Venu K, Subhakar K, Sritharan M. T-cell recognition of iron-regulated culture filtrate proteins of Mycobacterium tuberculosis in tuberculosis patients and endemic normal controls.Indian J Med Microbiol 2012;30:323-331

How to cite this URL:
Duggirala S, Venu K, Subhakar K, Sritharan M. T-cell recognition of iron-regulated culture filtrate proteins of Mycobacterium tuberculosis in tuberculosis patients and endemic normal controls. Indian J Med Microbiol [serial online] 2012 [cited 2020 Sep 29 ];30:323-331
Available from: http://www.ijmm.org/article.asp?issn=0255-0857;year=2012;volume=30;issue=3;spage=323;epage=331;aulast=Duggirala;type=0