anti-viral sg Flashcards
Herpes Viruses (chicken pox, AKA Varicella Zoster, VZV) CytomegalovirusCMV
hepatitis B
are these DNA, RNA, or retrovirus
DNA
Influenza A B C
Respiratory Syncytial Virus
Hepatitis C
are these DNA, RNA, or retrovirus
RNA
HIV-1 and HIV-2 aids
are these DNA, RNA, or retrovirus
retrovirus
general structure of a _
Nucleic Acid Core (DNA or RNA)
enzymes
Coat or Capside
Capsomere - protein subunits of the coat
some have lipoprotein envelope (carries antigens)
virus
General Considerations about Viral disease
- Viruses can attack human, animal, plant, and bacterial cells (bacteriophage)
- More than 400 species of viruses infect man, but only _ cause human disease
- Immunity against many viruses is _
- Different viruses can produce the same disease symptoms (e.g. upper respiratory tract)
- Same virus can produce different diseases depending on the host’s immunity and age.
- Viruses are small: Most viruses are 0.02-0.3 μm
- Viruses are not cells, they are obligate intracellular parasites
<50 cause human disease
immunity against viruses is lifelong
-Infection Process of virus
- _ (molecules on cell),
- Penetration & uncoating of genome,
- Replication/Transcription/Translation,
- Assembly, they have to reassemble
- Release,
- Secondary Infection
Adsorption
important receptor or HIV - CD4/CCR5 CXCR5
fuzeon CCR5 antagonist for HIV
Docosanol for HSV
3 types of viruses
DNA (Virus genome carried around in DNA form) Ex. Herpes
- Once penetrated and uncoated into _, viral DNA is transcripted into viral mRNA and replicated into more viral DNA
- viral mRNA goes to make proteins to get packaged with DNA to release (by host ribosomes)
nucleus
translated by host ribosomes for proteins, viral thymidine kinase, and viral DNA Pol. To replicate viral DNA -> assembly and release
3 types of viruses
Taken in by endocytosis, membrane fuses with nuclear membrane and uncoated by Amantidine and Rimantitidine.
RNA virus (flu)
- Single stranded viral RNA gets replicated in nucleus via cRNA to new Viral RNA
- Viral RNA can also be transcribed to Viral mRNA to make proteins
- Viral enzymes are released to create new viral enzymes and proteins for packaging and release (e.g. viral coat)
3 types of viruses
RNA retrovirus (Ex. HIV, carries genome around in RNA form, but goes through a DNA form inside the cell)
- genetic material exposed _
- Viral RNA matches up with cRNA to form double stranded DNA which gets taken into nucleus to replicate viral RNA, while other strands form viral mRNA for proteins, proteins and RNA packaged and released
outside of cell nucleus
- Attachment and penetration – uncoating in cytoplasm
- Viral genomic RNA + Reverse transcriptase -> cDNA-RNA complex
- Integrated into host cell DNA
- Replication -> new RNA and proteins -> release
_ immunity: B cell system, T Helper cells contact B cell holding correct antigen and MHC. TH cells produce cytokines to stimulate antibody production
B cell system, produce cytokines to stimulate antibody production
-Humoral immunity
_ immunity: destroys virus-infected cells,
secretes interferon – interferon activates cytotoxic T cells and other killer cells – induces _ to viruses
Cellular
induces resistance to viruses
_ take up and digest antigens to show antigens to helper cells
– surface with MHC -> production of IL-1
APC
protease inhibitors are most effective _ drug
HIV
_produce cytokines to promote immunity (IL-2),
contacts B cell holding the correct antigen w/ MHC
Helper T cell:
_activate cytotoxic t cell, natural killer cells and macrophages for virus-infected cells
, induces resistance of other cells to virus
Interferon:
_ binds antigen and can neutralize it, stem allows cells to recognize antigen to get swallowed by phagocyte
Antibodies:
General difficulties in viral chemotherapy
- Virus uses host cell machinery
- Narrow spectrum of antivirals
- Viral resistance
- Growth of virus may resume when drug is gone from system
- Virus is _
- Symptoms absent prior to viral large scale replication
- Immune system helps eliminate virus
- Lot of _ in viruses
intracellular
a lot of variability
passive or active immunity?
- With preformed Antiviral immunoglobulin
- Injected w/ antibodies to coat virus and induce phagocytosis
- Rapid onset of protection, lasts only months
- Good for immunodeficient patients, when rapid use needed
- Can be engineered antibodies or donor serum antibodies
passive
tx and prophylaxis
passive or active immunity
- Antigen administered to induce cellular/humoral immunity
- Takes time for protection, but stay immune for long time
- Ideally - > Prevents disease, low frequency needed, non toxic
- Creation of memory cells (T+B) when virus is presented later in life
- Used for prophylaxis
active
just prophylaxis
_ viral immunization
Passive
- ***Give to kids with RSV virus and can benefit them greatly - binds to F protein on virus surface and prevents viral entry into cells - RSV (RNA virus) most common cause of bronchitis and pneumonia in kids - 9x more deadly than flu - symptoms: edema, mucin, cell necrosis, obstruction
Pallvizumab
- Passive
- Binds to F protein on virus surface and prevents viral entry
- RSV (RNA virus) most common cause of bronchitis and pneumonia in kids
- 9x more deadly than flu
- symptoms: edema, mucin, cell necrosis, obstruction
INTERFERON
- produced by natural interferon producing cells
- express receptors that recognize viral DNA/RNA (TLR 7/9), viral intro creates type _ interferon
- produced by most normal cells
- activated by dsRNA, induce IFN production, intracellular double stranded receptors
- activates other interferon receptors, induces cell resistance
- Inhibits: penetration/uncoating, transcription/translation, viral glycosylation for maturation
- activates natural killer cells
TYPE 1
- Inhibits: penetration/uncoating, transcription/translation, viral glycosylation for maturation
- activates natural killer cells
INTERFERON