Lecture 3 - Cardio virology 1 Flashcards
how are retroviruses classified
enveloped, single-stranded RNA virus
T/F: retrovirus infection is host adapted
TRUE
summarize retrovirus replication
- virus enters cell by receptor-mediated endocytosis
- reverse transcriptase converts RNA into provirus DNA
- virus translocated in the nucleus and integrated into host cell genome
- transcription and translation of viral proteins
- virions assemble at plasma membrane
- leave via budding
what plays. acritical role in establishing genetic diversity of retroviruses
DNA reverse transcriptase and mutation rate
endogenous retroviruses
- normal genetic elements that are typically inactive
- vertical transmission
exogenous retroviruses
- infectious RNA
- horizontal transmission
what are the 3 mechanisms of oncogenesis
- insertional mutagenesis
- transduction of c-onc genes
- trans-activation
describe insertional mutagenesis
- inserts into host cell genome
2a. powerful promoters
2b. Disruption of tumor suppressor genes (sometimes) - cellular transformation due to unregulated expression
describe the transduction of c-onc genes
- capture host cell proto-oncogene
- incorporate into genome
- passed to progeny
- gene expressed in an unregulated manner
- cell transformation
describe trans-activation
- activation of protein product
- activation of genetic component
- dysregulation of growth regulatory genes
- cell transformation
what codes for trans-activation proteins
BLV and HTLV
T/F: tumor, nodule, and mass are terms that are specific to different abnormal proliferation of cells
FALSE - nonspecific terms
does neoplasm imply a malignant or benign tumor
No; term for new growth
adenoma
benign neoplasm of glandular cells
carcinoma
malignant neoplasm of epithelial cells
sarcoma
malignant neoplasm of mesenchymal cells (fat/muscle)
lymphoma
malignant neoplasm of lymphocytes
melanoma
malignant neoplasm of melanocytes
germ cell tumor
malignant neoplasm of germ cells
the higher the level of virus replication, the ____ likely an integration near a proto-oncogene will occur
more
describe lentivirus
- horizontally transmitted, non-oncogenic retroviruses that cause persistent infection
T/F: lentivirus can be vertically transmitted
TRUE
what are progressive lentivirus diseases characterized by
(hint: 3 things)
- inflammation
- degeneration
- immunosuppression
why are lentiviruses lifelong
they integrate into the host cell genome
what lentiviruses have a tropism for what
macrophages/monocytes and T-helper cells
