Transcript Herpesviridae and You

Herpesviridae and You
Adrienne Manuel
I400
THE Immune system: a brief overview
For Humans and animals to have
maximum health, their bodies needs
defense systems that are able to
recognize and repel diseases and
pathogens—the Immune System.
The Immune system is made up of cells
and tissues. What makes the immune
system so remarkable is its ability to
recognize between self and non-self.
Overview continued…
The immune systems carries several types
of fighter cells (B lymphocytes, T Cells,
Phagocytes, Cytokines, etc) in the body to
help recognize certain disease and
viruses.
Types of Immune Cells
 B cells work on creating antibodies in bodily
fluids. These Antibodies attack antibodies in the
bloodstream but cannot penetrate into cells. B
cells create these antibodies that are then
“customized” the antigen
 Immunoglobulins help coat microbes, fight
viruses, killing bacteria, etc. T cells are also
another helpful resource to the immune system.
T Cells aid the immune system in two
different ways: some direct and regulate
immune responses; others directly attack
infected cells.
Phagocytes are large white cells that
ingest foreign microbes and particles.
Cytokines are chemical messengers
shared amongst to access an antigen and
what immune response to take.
 Lastly there is the
complement system
that consists of
roughly 25 proteins
that aid antibodies to
destroy antigens. The
Complement proteins
circulate in the blood
non-active.
Creating an Immune Response
 Once the pathogens find their way into the body
(through a cut through the skin or tiny
abrasions), they must go through the wall linings
that are made up of tightly packed epithelial
cells. These cells are hard to penetrate because
they are covered in a thick mucus. The mucus
contains Immunoglobulin A, which guards
entrances, and usually the first antibody a
microbe encounters. When an antigen is found,
antibodies are triggered by the B cells. The B
cell surrounds the antigen and digests it.
The Herpes Virus

 100 different strains
found in a myriad number
of species
 Belongs to the
Herpesviridae Family
 There are three
Subfamilies:
Alphaherpesvirinae,
Betaherpesvirinae,
Gammaherpesvirinae
HERPES!
 These viruses all have certain characteristics in
common, like the ability to establish latency
during primary infection
 Herpes viruses are able to hide within the cells
in the body as protection from the antibodies
produced by the immune system
 The viruses are triggered due to factors of
stress, illness, or poor nutrition.
HERPES SIMPLEX 1 and 2
Similar proteins: Glycoprotein B
 This protein is exposed
on the viral envelope and
on the surface of infected
cells.
 91% match found in the
Protein B in HSV-2
 are responsible for the
virus’s infectivity and to
the induction of host
immune responses.
UL52
 Interacts with 2 other proteins.
UL5, UL8.
 UL52 combined with UL8,
Herpes simplex virus type 1
expresses a heterotrimeric
helicase–primase,
 UL5 and UL52 subunits of the
helicase–primase seem to play
an important role in modulating
the helicase–primase activity
and integrating this activity into
the whole function of the
replisome
UL9
 UL9 is responsible for
the virus’ DNA
 It is thought that UL9
binds the origin of
replication
How Herpes work
 Viral glycoproteins allow the virus to attach and enter the
cell. The envelope and cell membrane fuse the viral
capsid is released into the cytoplasm. Viral DNA enters
the nucleus and the capside is discarded. Host enzymes
catalyze the early transcription, and viral mRNA directs
the production of viral enzymes. These enzymes
facilitate the replication of viral DNA.
 Late transcription produces the mRNA encoding the
production of glycoproteins and capsid elements. The
capsid components return to the nucleus and the DNA is
packaged. he glycoproteins fix themselves to the nuclear
membrane and the DNA filled capsid acquires this coat
as it buds out of the nucleus. The virus is released
from the cell by unknown mechanisms
Herpes Simplex Proteins and their
similarities
The DNA sequences of HSV-1 and HSV-2
are 50% identical in their nucleotide
sequences and their proteins are even
more closely related.
HSV-1 is responsible for more than 90% of
oro-labial herpes (blisters found on the lip)
whereas HSV-2 is responsible for over
90% of genital herpes infections.
 The comparison above taken from BugSpray below shows genome
alignment based on similar genes and illustrates the similar gene
arrangement between the HSV-1 and HSV-2. Lines run from the
genes on the top genome (HSV-2) to the gene with the best BLAST
hit in the bottom genome in HSV-1. The Green lines indicate pairs
of genes that similar to the same strand. The red lines indicate gene
pairs that code on the opposite strand. There are no rearrangements
or reordering of genes between these two viruses.