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Ipr1 gene mediates RAW 264.7 macrophage cell line resistance to Mycobacterium bovis
1Key Laboratory of Animal Reproductive Physiology & Embryo Technology, Ministry of Agriculture, College of Veterinary Medicine, Northwest A & F University, Yangling, China.
Abstract:
Tuberculosis caused by Mycobacterium bovis (M. bovis) seriously affects efficiency of animal production with impacts on public health as well. Effective programmes of prevention and eradication of M. bovis infection therefore are urgently needed. Intracellular pathogen resistance gene 1 (Ipr1) is well known to mediate innate immunity to Mycobacterium tuberculosis (MTB), but there are no reports as to whether Ipr1 can enhance the phagocytic ability of macrophage against M. bovis. In this investigation, RAW 264.7 macrophage was transduced with lentiviral vector carrying Ipr1 (named Lenti-Ipr1); transgenic cells were identified by RT-PCR and western blotting. Transgenic positive cells (R-Ipr1) were then infected with an M. bovis virulent strain, with non-transduced cells used as control. When cell proliferation, viability and apoptosis of the two groups were investigated, it was found that infected RAW 264.7 died by necrosis whereas R-Ipr1 underwent apoptosis. Furthermore, the numbers of intracellular bacteria in R-Ipr1 were lower than those in control cells (P < 0.05). To identify the role of Ipr1, we measured the genes of Casp3, Mcl-1 and NOS2A which associated with macrophage activation and apoptosis by real-time quantitative PCR. The results demonstrated that Ipr1 gene expression can enhance anti-M. bovis infection of macrophage. This establishes a basis for the future production of Ipr1-transgenic cattle to strengthen the tuberculosis resistance.
Insights
Intracellular pathogen resistance gene 1 (Ipr1) enhances macrophage resistance to Mycobacterium bovis (M. bovis) infection. This finding supports developing Ipr1-transgenic cattle for improved tuberculosis resistance in animals.
Area of Science:
- Immunology
- Genetics
- Veterinary Medicine
Background:
- Bovine tuberculosis, caused by Mycobacterium bovis (M. bovis), significantly impacts animal production and public health.
- Effective prevention and eradication programs for M. bovis infection are crucial.
- The role of Intracellular pathogen resistance gene 1 (Ipr1) in macrophage defense against M. bovis is not well understood.
Purpose of the Study:
- To investigate the effect of Ipr1 gene expression on macrophage phagocytic ability and resistance against M. bovis infection.
- To determine if Ipr1 can enhance the innate immune response of macrophages to M. bovis.
Main Methods:
- RAW 264.7 macrophages were transduced with a lentiviral vector carrying Ipr1 (Lenti-Ipr1).
- Transgenic cells (R-Ipr1) and control cells were infected with a virulent M. bovis strain.
- Cell proliferation, viability, apoptosis, and intracellular bacterial load were assessed.
- Gene expression of Casp3, Mcl-1, and NOS2A was analyzed using real-time quantitative PCR.
Main Results:
- Macrophages expressing Ipr1 (R-Ipr1) exhibited apoptosis upon M. bovis infection, unlike control cells which underwent necrosis.
- R-Ipr1 cells showed significantly lower intracellular M. bovis counts compared to control cells (P < 0.05).
- Ipr1 gene expression modulated the expression of genes associated with macrophage activation and apoptosis.
Conclusions:
- Ipr1 gene expression enhances the anti-M. bovis infection capacity of macrophages.
- This study provides a foundation for developing Ipr1-transgenic cattle to bolster tuberculosis resistance.
