Hello, I am a current intern at Nationwide
Children's Hospital in Columbus Ohio and I am
having some trouble with teaching myself some
cell signaling pathways for microbial
pathogenesis. I taught myself the three
complement pathways to destroy pathogens through
the use of C5bC78 added to around 10-16 C9s to
make a MAC, but I am trying to teach myself the
toll-like receptor pathways and others like
that. I am very much a visual learner but these
pictures that I am getting online are too
complex for me to decipher. Also, the videos
online that I am finding are too simple and I
need to go more into depth. I have a
presentation of what I did in the lab for the
past few months coming up on August 10th and I
need to be as well prepared as I can be because
a scholarship is on the line that I am competing
with other students for and it is vital that I
am well prepared to be as versed as I can be in
the topic of microbial pathogenesis and
immunology. Are there any sites or books
that you would recommend me looking for? I would
really like help here! Thanks so much. |
Answer 1:
Perhaps it would be useful to step back a
little and think about the major pathways that
have been identified that play roles in immunity
to pathogens. First innate immunity,
which is the rapidly responding arm of the
immune system that includes TLRs (Toll-like
Receptors) and interferon response pathways.
In a nutshell, our immune cells have developed
specific receptors for components of bacteria
such as flagella and cell envelope components,
and components of viruses including double
stranded RNAs. Once these components are bound,
signals are sent to the immune cell and various
pathways that kill or tie up bacteria and
viruses, or kill cells harboring intracellular
pathogens, are activated.
Second: acquired immunity, which takes
more time and generates highly specific
antibodies (humoral response) and T cell
receptors (cellular response) that can recognize
antigens on target cells. Humoral immunity is
very useful against pathogens that cannot enter
our cells- for example antibodies and complement
can poke holes in the pathogen, antibodies to
components like capsules that allow bacteria
to "slip" out of the grasp of white blood
cells/macrophages can "opsonize" them, which
allows them to be recognized and engulfed by
immune cells. However, intracellular pathogens
can escape the humoral system. You might ask
how this is possible since you would think the
pathogen would need to pop out of the host cell
to gain entrance to a neighboring cell- but,
many pathogens have developed ways to travel
from cell to cell without ever having to leave
the cell and be exposed to antibodies or
complement in the blood. (Examples are Listeria,
Shigella, Burkholderia).
The complement system is involved in both
innate immunity and acquired immunity.
The classical complement pathway requires
antigen antibody complexes for activation and
eventual killing of pathogens, whereas the
alternative pathway works without antibodies,
involving C3b, which can bind directly to
pathogens and initiate an activation pathway.
I enclose a couple of papers focused on
innate immunity, which seems to be the focus of
your research?
immunityto bacteria
toll-likereceptors
For a general textbook, this URL may be
useful- search chapters on innate and acquired
immunity-
textbookof bacteriology
Cheers,
|
Answer 2:
Great question! I have two recommendations
for you. First, check out Todar's Online
Textbook of Bacteriology mentioned in the answer
above.
We use this free on-line textbook to teach
Bacterial Pathogenesis, and it is fantastic! I
think you will find the answers to most of your
questions there by going to the "Table of
Contents" and looking under the heading
of "Bacterial Relationships with Animals". There
are two fantastic chapters on Immune Defense
against Microbial Pathogens! Second, you can
also try the textbook "Bacterial Pathogenesis: A
Molecular Approach" by Salyers and Whitt. I
would recommend either the 2nd or 3rd edition.
This textbook also has a thorough description of
immune defenses against microbes. These are the
two textbooks we use to teach Bacterial
Pathogenesis here at UCSB, and I am sure you
will find what you are looking for.
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