Question

Describe two arms of the immune response, types of recognition proteins utilized by the immune system, and elaborate on how an antibody molecule achieves high specificity for its antigen

Answer 1

The primary function of immune system is to provide protection against the pathogenic organisms. The two-arms of immunity are,

· Innate immunity

· Adaptive immunity

Innate immunity is a nonspecific resistance (body’s 1st line of defence) that we have from the time of birth. Innate immunity is not triggered by the specific antigens; so, it is a non-specific defence system regardless of the type of invading agent. Our body is able to prevent the occurrence of any disease, entry of pathological organisms, and spread of infections through the innate immunity only. The seven defensive mechanisms of innate immunity include physical barriers, phagocytes, immune surveillance, interferons, complement system, inflammation and fever.

Adaptive immunity provides specific immunity against particular pathogens (generates specific antibodies) and is acquired after birth. This includes the generation of memory B cells, which can specifically act against particular pathogens upon their second exposure onwards. One of the major functions of adaptive immunity is to differentiate between the self and non-self-cells and provides specific immunity against a selective pathogen.

Pattern recognition receptors (PRRs) are one of the sensory components of the innate immune system. They identify two different components produced as a result of cellular damage or cell death. They are, PAMPs (pathogen-associated molecular patterns, and DAMPs (damage-associated molecular patterns).

The PRRs can recognize the peptidoglycan, and lipopolysaccharide molecules that are unique to the bacterial cells, thus, identify the bacteria.