Mycobacteria Phagosome Maturation - Book Report/Review Example

Download file to see previous pages This research uses a culture of macrophage-like cells (J774) cultured and kept in Cellgro, a medium with appropriate additives. These cells were then inoculated by exposure to the pathogen, M. bovis, incubated, lysed and then prepared for the investigation. After latex bead compartment isolation, flow cytometry and analysis of β-hexosaminidase activity, epiflourescence, laser scanning confocal and electron microscopy, the cells were then analysed for markers and phagosome maturation stage. This was done by gel electrophoresis, GTP-binding overlay assay and Western Blot analysis (Via et al, 1997).
The findings found that initially, the phagosomal cells containing M. bovis BCG had a very similar GTP-binding process as those containing the latex beads (Via et al, 1997). The presence of M. bovis BCG caused an increase in the number of rab5 proteins accumulated by the cell, whereas the presence of the latex beads caused the reverse. Additionally, rab7 cannot be detected in those cells with MPC whereas LPC cells have fluctuating levels of rab 7 throughout the incubation period (Via et al, 1997). This suggests that MPC gains the characteristics of the early endosome (in this case, the presence of rab5 proteins) but can remain isolated from the late endosomal cell characteristics (such as the lack of rab 7 proteins). These results illustrate not only the pattern that phagosome maturation takes but how M. bovis manipulates these maturation events to prevent lysis or expulsion from the host cell (Via et al, 1997).
A study by Kitano, Nakaya, Nakamura, Nagata, & Matsuda. (2008) reinforces the importance of rab5 proteins in the endocytic pathway and the involvement of GTP-binding proteins in the maturation of the phagosome. This research used newly developed imaging techniques to track the rab5 activity in a cell during engulfment of apoptopic thymocytes, finding ...Download file to see next pagesRead More