HMX Immunology Practice Questions and
answers 100% with 100% Complete Solutions
|verified |verified &updated 2024
Streptococcus pneumonia is an extracellular bacterium that is a leading cause of
bacterial pneumonia and meningitis, particularly in children and the elderly.
Fortunately, most cases of S. pneumonia can be prevented with a vaccine that
contains components of the bacterial capsule. The vaccine is known to lead to the
production of antibodies that recognize intact bacteria. What are the most likely
mechanisms activated by these antibodies that result in protection against S.
pneumoniaeinfection? (select two Answers) - ✔✔The key is that S. pneumonia is
an extracellular bacterium. The vaccine elicits a humoral immune response, which
generates antibodies that bind to the surface of the bacterium. The antibodies
bound to bacteria can activate complement (direct killing of the bacteria) and
opsonization followed by phagocytosis. ADCC is usually directed against viral
proteins displayed on the surface of cells. It is conceivable that antibodies could
neutralize the function of bacterial components, but direct killing by complement
and phagocytosis are the best-characterized mechanisms for eliminating
extracellular bacteria.
,There is strong interest in developing a vaccine that would prevent human
immunodeficiency virus (HIV) infection or substantially reduce viral loads in a
person with HIV. HIV infects immune cells by binding to a receptor called CD4 on
the surface of those cells. Laboratory studies have identified rare antibodies that
bind to intact HIV viral particles and effectively control the virus in certain
individuals. Structural studies revealed that some of these antibodies bind to a
protein on the surface of HIV at the same location where this protein binds to
CD4.
What is the most likely mechanism of action of these antibodies? -
✔✔Neutralization
How many distinct peptide chains are found in a single molecule of IgG? -
✔✔Each IgG antibody is comprised of two heavy chain and two light
chain peptide chains joined by disulfide bridges.
How many distinct binding sites are found in a single molecule of IgG? - ✔✔Two
, Which antibody protects from proteases that are commonly found in the gut? -
✔✔IgA
Neutrophils, NK cells, and macrophages all have receptors for the portion of the
antibody, and use this to recognize antigens that are coated with antibodies. -
✔✔Fc
Antibodies can cause disease by ________________________ - ✔✔a combination
of complement fixation and opsonization, leading to frustrated phagocytosis
and inflammation-mediated damage forming complexes in the circulation that
can deposit in vessel walls and potentially trigger further immune activation
recognizing antigens that are part of our own cells, leading to opsonization and
destruction by phagocytes recognizing antigens that are part of our own cells,
leading to complement activation
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Examsplug. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $13.24. You're not tied to anything after your purchase.
