Question

31)

Which of the following would not be a consequence of an antibody:antigen interaction?

	A.	agglutination of antigens
	B.	neutralization of toxin
	C.	activation of complement
	D.	opsonization
	E.	prevent adherence of pathogens
	F.	All are possible consequences of antibody:antigen interactions

32)

Which statement among A-D is false regarding bacterial toxins?

	A.	Exotoxins are not capable of stimulating an antibody response by the body and thus are undectable.
	B.	Cholera toxin results in the loss of tremendous amounts of water from an affected individual.
	C.	Shiga toxin, tetanus toxin, and hemolysins are all types of exotoxins.
	D.	Superantigens elicit a hyperactive response by the immune system and can lead to shock.
	E.	None are false, A-D are all true statements.

Answer 1

Ans. (F) all are possible consequences of antibody:antigen interactions.

Explaination: When a foreign antigen enters humans, different immune responses are developed in our body to fight against the antigen. These responses include agglutination of antigens (aggregation of antigens with antibodies to neutralize their effect), neutralization of toxic( conversation of toxic antigens to non-toxic forms via enzyme actions), activation of complement system ( a part of immune response for removal of toxins and harmful microbes), prevention of adherence of pathogen to the host cell preventing pathogen attack. All these strategies are adopted by host to cope up with foreign antigens or microbial attack.

Ans. (A) exotoxins are not capable of stimulating an antibody response by the body and thus are undetectable.

Explaination: Exotoxins are toxic chemicals which are released by bacteria out of its body. When exotoxins are injected by bacteria into host, these toxins are detected by immune response system of the host and immune response system is activated to remove this toxin or to convert it into non-toxic form.

Cholera is characterized by heavy loss of water caused by its paothen toxins. Shiga toxins, Tetanus toxins and hemolysin are toxins released out of the body of pathogen and hence are examples of exotoxins. Superantigens are antigens (type I toxins)which cause higher level activation of immune system and lead to harmful effect.