Exam 5-Viruses

Nucleoside analogs

Interfere with DNA and RNA synthesis

Acyclovir

Nucleoside analog, Virus infected cells use drug in place of normal nucleoside which leads to DNA synthesis, Herpes and shingles treatment.

Ribavirin

Nucleoside analog, induces high mutation rate of RNA virus, Hep C and respiratory syncytial virus.

Zidovudine

Nucleoside analog, competitive analog blocks synthesis by reverse transcriptase, fairly toxic

Nevirapine

Enzyme inhibitor, Inactivates reverse transcriptase, HIV treatment

Indinavir and saquinavir

Enzyme inhibitors, Protease inhibitors, HIV treatment

Raltegravir and elvitegravir

Enzyme inhibitors, Integrase inhibitors

Enfuviritide

Fusion or exit inhibitors, Stops HIV fusion

Olsetamivir (tamiflu), Zanamivir (Relenza), Peramivir (Rapivab)

Fusion or exit inhibitors, prevent influenza virus release.

Interferon

Protein released by cells in response to viruses, helping to inhibit viral replication and boost the immune response.

Alpha-interferon

Hep C treatment

Prions

infectious proteins that can cause misfolding of normal proteins in the brain, leading to neurodegenerative diseases that are always fatal.

Prion diseases

1. Scrapie = sheep

2. Mad cow disease = cows to humans

3. Kuru = humans

4. Creutzfeldt-Jakob disease (CJD) = humans

5. Gerstmann-Straussler-Scheinker syndrome = humans

6. Fatal Familial Insomnia = human

7. Chronic Wasting Disease = deer

Prion transmission

1. Eating CNS of an infected animal

2. Transplanting infected nerve tissue

3. Contaminated surgical instruments

Prion mode of action

1. Can induce abnormal folding of NORMAL cellular prion proteins in the brain

2. Causes large vacuoles in the brain = spongiform encephalopathy

Viroids

small infectious agents that consist of a short circular RNA molecule lacking a protein coat. They cause plant disease. 300 to 400 nucleotides long.

Diphtheria toxin

Inhibits protein synthesis, Corynebacterium diptheriae

Erythrogenic toxin

damage to blood capillaries which cause red skin rash, scarlet fever

Botulism toxin

Neurotoxin that prevents transmission of impulses from nerve to muscles-flaccid paralysis, food poisoning

Tetanus toxin

Neurotoxin that blocks the relaxation pathway of muscle contraction-spastic paralysis, tetanus

Vibrio enterotoxin

Causes the discharge of fluids and electrolytes in the small intestine, cholera

Staphylococcus enterotoxins

Similar to vibrio enterotoxin and toxic shock syndrome (super activation of immune system), staphylococcus aureus

Inactivated/killed whole microbe vaccine

Inactivate the organism with formaldehyde or heat, small body response, may carry LPS, discomfort at injection, not long lived

Live attenuated vaccines

Mutated strains used that are less virulent and no longer cause disease, long immunity, may not need booster, MMR

Subunit vaccines

Single antigen or mixture of antigens, administered more that once, used when whole agent vaccine are dangerous or cause the wrong response.

Toxoids

Inactivated toxins, few side effects, DPT

polysaccharide vaccines

Not as immunogenic as proteins, conjugate vaccine-bind the polysaccharide to a protein (toxoid)

Nucleic acid vaccines

Injected nucleic acid into cells, your cells makes the protein which causes the immune response, COVID-19-mRNA