Module 4 Home	Biological Lab	Social Science Issue	Process of Science	Web Exercise
What is interdisciplinary Science? The example of Immunity Studies
In Module 4 - Lab you learned about how plants defend themselves against pathogens. As it turns out, there are some significant similarities between plant defense and mammalian defense against pathogens. Here you will learn how the work of scientists one field or area of research can provide important new understanding to scientists in very different fields

 

 

 

 

 

 

As you have already learned in the Lab Exercise, plants have two immune systems allowing them to fight PLANT PATHOGENS. In fact, all living organisms have ways to protect themselves against an attack by potential pathogens. Simple organisms such as fungi have weapons to resist bacteria (one of the most famous fungal weapons is the molecule called Penicillin, the first antibiotic discovered and widely used for human health). Some bacteria attempt to fight back by producing a protein that will inactivate the antibiotic (they develop ANTIBIOTIC RESISTANCE). Bacteria themselves are attacked by a specific type of virus (Bacteriophages) but some bacteria can produce proteins called restriction enzymes that will cut in pieces the DNA of the virus. The defense systems of higher organisms like plants and animals are much more complex. They allow the organism to recognize a pathogen and to activate signaling cascades leading ultimately to molecular events that kill the pathogen and prevent disease from developing. The most complex immune system is the one of vertebrates (animals with a spine, such as Humans).  It is composed of two interconnected systems:  innate immunity and adaptive immunity. Innate immunity in vertebrates is a pre-formed immunity, which means that many of the proteins involved in this immune system are present in the organism even when the organism is not under attack by a pathogen. This type of immunity is the one found in plants and non-vertebrate animals. In plants, innate immunity can be viewed as encompassing both the PAMP-triggered immunity (PTI) and the effector-triggered immunity (ETI) you’ve learned about in the Introduction to the Lab Exercise Adaptive immunity is an even more sophisticated immune system present only in vertebrates (including Humans).  It is very efficient and has the unique characteristic of having a ‘memory’:  if the same pathogen attempts to infect an organism for a second time, the defense response will be stronger than the first time (this is how vaccines work to protect us against a specific pathogen). Adaptive immunity involves the production of molecules called antibodies that are produced only after a pathogen has entered an organism and after the organism has recognized it. The antibodies produced are directed specifically against the particular pathogen involved in the attack and ensure its destruction with the help of specialized cells. Innate immune responses of plants and humans are generally different, but recent studies show that they also have some interesting similarities. For example, some of the same PAMPs (Pathogen-associated molecular patterns) that activate PTI in plants also activate innate immunity in humans. Plant PPRs (Pathogen recognition receptors) and RESISTANCE PROTEINS have structural similarities with PRRs from humans. Signaling cascades in plants and humans involve some of the same kinds of proteins and allow the production of some similar antimicrobial compounds. During the Web Exercise you will investigate these similarities using BIOINFORMATIC tools. Because of these similarities, plants are often used as ‘MODEL SYSTEMS’ to study innate immunity. For scientists, working with plants can be much easier than working with animals. To study innate immunity, plants are also a simpler organism to work with since plants don’t have adaptive immunity that can complicate the understanding of innate immunity when studied in vertebrates. Therefore, studying plant immunity can help us to understand human innate immunity.  This is one of the numerous examples of interdisciplinary science.  That is, sometimes two areas of study (disciplines) that might seem at first completely unrelated (e.g., plant pathology/human immunology), nevertheless turn out to provide great insights into each other.