Question

1.

a) Contrast the outcomes of macrophage ingestion for L. monocytogenes versusM.tuberculosis

b)Explain how interactions between Mtb and the host help create granulomas, and what function

granulomas serve

Answer 1

1.
a. Macrophage activation contributes to the strong immune response upon infection. Activated macrophages kill l monocytogenes by blocking phagosome escape.
In non activated macrophages, bacterial factors generally prevail, and l monocytogenes can escape from the vacuoles and grow within cytoplasm.
Activated macrophages generate reactive oxygen or nitrogen intermediates early after bacterial uptake, which prevent the bacteria from escaping vacuoles into cytoplasm.

The interaction between the macrophage and mycobacterium tuberculosis is mediated by a variety of macrophage membrane associated proteins.
The infectious process by intracellular pathogens is very complex, and it initially involves the adherence of the microorganisms to the surfaces of the phagocytic cells.
The complement system is composed of a group of serum proteins and their corresponding receptors located on the surfaces of many cells including phagocytes.

b the granuloma formation process starts shortly after infection. When inhaled mtb is ingested by and transported across the alveolar epithelium by AM's into the lungs, tissue and adjacent lymph nodes, dissemination any ensues through the lymphatic and blood vessels.
This process initiate cascade of events involving the formation of pro and anti inflammatory cytokines and chemokines. Does accumulation of cells lead to the formation of granulomas.
the main function of granuloma is to localise and contain mtb.