Which globulins make powerful contributions to both nonspecific resistance and specific immunity?
A Albumin
B Fibrin
C Interferons
D Complement
E Collagen
The correct answer and explanation is:
The correct answer is D. Complement.
The complement system is a group of proteins found in the blood plasma and is an essential part of both the innate immune system (nonspecific resistance) and the adaptive immune system (specific immunity). It consists of about 30 proteins that work together to fight infections, promote inflammation, and remove damaged cells.
Complement proteins are activated in response to infection or injury. Once activated, they can directly destroy pathogens through a process known as “membrane attack complex” formation. This complex creates pores in the membranes of pathogens, leading to their destruction. Complement proteins also assist in opsonization, a process where they bind to pathogens and mark them for destruction by other immune cells, such as macrophages.
In terms of nonspecific resistance, the complement system helps to rapidly respond to a wide range of pathogens without prior exposure. This response does not require the immune system to “learn” about the pathogen first, unlike specific immunity. Complement proteins recognize patterns on pathogens, which is characteristic of innate immunity.
In the context of specific immunity, complement proteins can enhance the adaptive immune response. For example, the activation of complement can assist in the production of antibodies and the formation of immune complexes. These interactions help to strengthen the body’s targeted immune response to pathogens that have been previously encountered, improving the efficiency of the immune system.
Thus, complement proteins contribute to both nonspecific and specific immunity by defending against infections and enhancing the body’s ability to fight off pathogens. They bridge the innate and adaptive immune systems, making them a powerful force in maintaining health.