Secretory IgA produced in the epithelium of mucosal surfaces has several functions in protective immunity. Among these are neutralization of pathogens or toxins in the gastrointestinal tract lumen or in epithelial cell endosomes, and transport of pathogens or toxins across M cells for delivery to lamina propria dendritic cells. All of these functions share the common feature that they:

The following are some mechanisms used by pathogens to evade immune system cells’ influences except:

Unlike defects in antibodies or T cell functions, defects in complement components often lead to autoimmune-like symptoms, rather than to increased susceptibility to infections. This is because

Individuals that lack all T cells have the most severe form of immunodeficiency (SCID) and will not survive past their first birthday without a bone marrow transplant from a healthy donor. These individuals fail to make antibody responses to the normal childhood vaccines because

Which of the following contribute to dendritic cells tolerance in mucosal immunity?

Salmonella crosses the mucus barrier (epithelium) to lumen by

When Shigella gains access to the intestinal epithelium, which of the following apply

 Herpes Simplex virus, causes recurrent cold sores in infected individuals. Which of the following explains the recurrent infections?

Pathogens are taken up using the following mechanisms EXCEPT:

Attachment of HIV is possibe by the interaction of the…………………….with CD4