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26 Cards in this Set
- Front
- Back
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Herpesviridae properties
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Enveloped, icosahedral nucleocapsid, DNA virus
Small host range LATENCY (in non or semi-permissive cells) -> life-long infxn Lytic in permissive cells |
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Herpesviridae families
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Alpha (Simplexvirus, Varicellovirus) - latent in neurons, lytic in epidermal
Beta (CMV, Roseolovirus) - limited host rage, latent in secretory, lymphoid, & kidney cells Gamma (HHV-8, EBV) - narrowest host range, latent in epith, infect B & T cells |
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HHV1 alternative name
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HSV-1
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HHV2 alternative name
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HSV-2
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HHV3 alternative name
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VZV
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HHV4 alternative name
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EBV
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HHV5 alternative name
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CMV
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HHV6 alternative name
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roseola infantum (major cause)
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HHV7 alternative name
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roseola infantum (minor cause)
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HHV8 alternative name
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KS
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Herpesviridae replication method
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rolling circle replicaton in NUCLEUS (benefit - no telomeres needed: doesn’t need to worry about repairing ends)
DNA linear in virus, circular during infxn |
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Herpesviridae genes
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Immediate-early (alpha proteins): regulatory (shut off host cell prot synthesis & destroys host DNA/RNA)
Early (Beta proteins): replicates viral DNA (DNA pol, primase, helicase) Late genes (gamma proteins): capsid & envelope proteins |
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Herpesviridae infection process
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1) Attachment - gB & gC bind to ECM, gD interacts w/ cell receptor
2) Penetration - membranes fuse 3) Uncoating - tegument and nucelocapsid in cytoplasm - attach to microtubules -> move into nucleus |
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Latency
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Genes controlling latency still expressed
low level transcription |
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EBV attaches to? On what cell?
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CR2 (aka CD21) on B-cells
MHCII as co-receptor |
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EBV symptoms/serology
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LN swelling, fatigue, flu-like symptoms, exudate covered tonsils (moreso than w/ CMV)
HETEROphile Ab , "atypical" lymphocytes (Downey cells) proliferation of B-cells |
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heterophile Ab
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See in EBV: IgM w/ multiple affinities - beef RBC (cold agglutination)
Self-Ag -> lysis Ampicillin -> rash NOTE: also have Ab specific to EBV(which stay after infxn) |
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EBV pathology
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Lymphocytosis: CD8+ T-cell proliferation to control B-cell proliferation -> atypical lymphocytes
overactive immune response -> Infectious mononucleosis lack of effective immune response -> lymphoma |
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self-reactive heterophile Ab complications
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Rare, but severe: Hematologic (anemia, thrombocytopenia, neutropenia)
Splenic rupture, Neurologic, death (rare c/o splenic rupture, neuro, or airway obstruction) |
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EBV latency: what is seen, what is happening, what is on B-cells
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rarely see symptoms, no virions made, regulatory genes expressed
B-cell has: LMP = Latent membrane proteins, EBNAs - EBV nuclear Ag |
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Burkitt's Lymphoma
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childhood malignancy: c-myc next to Ig enhancer in B-cells
cancer in people w/o good immune response rare except in Africa (environmental co-factors?) |
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Oral Hairy Leukoplakia
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non-malignant cell assoc. w/ EBV
Often see in AIDS pt looks similar to Oral thrush (candida infxn - more prevalent in AIDS pt but could be EBV) |
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EBV Diagnosis
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Blood smear for atypical lymphocytes (CD8+ CTL)
heterophile Ab (IgM = acute, IgG = chronic or prior EBV infxn - have for life) |
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CMV
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heterophile Ab negative
causes cell enlargement; Giant cell w/ halo inclusion |
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CMV and AIDS pt; disease
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CMV retinitis, pneumonia
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CMV and pregnancy
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Immunosuppressed - fatality or neuro dmg
hearing loss (most common cause other than genetics) |
