Question

1. Briefly explain how the interplay between the skin and all other 1st and 2nd line non-specific immune defense mechanisms protect you from microbial invasion.

2. Briefly explain how the inflammatory process is initiated and how the underlying events contribute to the observed symptoms.

Answer 1

1. the immune responses are taken place towards the invading pathogen which can be harmful to the human body. As seen by the first line and the second lien defense mechanism, the first lin defense is known as the innate immune response which is the immune response provided from the birth, for example, blinking of the eye. Further, there are three different immune responses as follows:

• Physical: Physical barrier is the primary defense mechanism that is like the skin to protect the direct entry of the pathogens inside the bloodstream. For example, the skin creates sweat and sebum which kill the pathogens present on the surface of the skin.
• Chemical: In the case of the chemical response there are many body fluids that play a crucial role in the defense mechanism against the pathogens. For example, hydrochloric acid in the stomach lead to destroying the affected pathogens.
• Cellular: Whenever the infection of the viruses takes place then the toll-like receptors inside and on the surface of the cell activates and allows to generate the immune response in the form of the interferon secretion which detects the pathogen and allow to produce the killing signal for the cytotoxic T-cells.

2. Whenever the pathogen invades in the bloodstream, the surface proteins of the pathogens are detected by the immune cells through the help of a toll-like receptor in the form of PAMP and thus lead to the activation of the chemokines which generate the signal response for the neutrophils and the macrophages. these cells reach till the infected site through the crawling or the gliding movement on the extracellular matrix under the influence of the chemokines and thus the migration process is called chemotaxis. After reaching to the infected site the immune cells starts secreting the pro-inflammatory cytokines which kill the pathogen and after that the anti-inflammatory cytokines to reduce down the inflammation in the pathogen present region. This is the cascade of the event and many protein such as RhoGTPase plays a crucial role in the migration of these immune cells such as neutrophils and macrophages.