Exam 2 Flashcards
Why are antiviral agents hard to develop?
There are severe side effects because replication is with host cell
Antiviral agents often target processes that are similar in both the virus and host cells, leading to potential toxicity.
Why is the influenza virus prone to antigenic shift?
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Antigenic shift occurs due to genetic reassortment when two different strains of the virus infect the same cell.
On what viral features is the Baltimore Model of viral classification based?
Whether genome is RNA or DNA, single or double, if strand directly encodes protein
The Baltimore classification system categorizes viruses into seven groups based on their nucleic acid type and replication mechanism.
Do HPV and HIV have the same or different tissue tropism?
Different tissue tropism
HPV primarily targets epithelial cells, while HIV primarily infects immune cells, particularly helper T cells.
What type of organisms can viruses infect?
Viruses infect all taxonomic groups: bacteria, eukaryotes, archaea
This broad host range includes organisms from simple bacteria to complex multicellular organisms.
How does a virus obtain its envelope?
Capsid will keep the viral genome intact. The capsid is then further encased by the envelope
The envelope is derived from the host cell membrane during the budding process.
Does AIDS have a cure?
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While there is no definitive cure for AIDS, antiretroviral therapy can effectively manage the disease.
What are the different ways viruses can evolve?
Mutation, recombination, and natural selection
These mechanisms contribute to viral diversity and the emergence of new strains.
Know the difference between lytic and lysogenic bacteriophage infections.
Lytic: virulent with lysis of host cell; Lysogenic: phage genome that turns into a host cell
Lytic infections result in cell death, while lysogenic infections integrate viral DNA into the host genome.
With respect to viruses, know what host range refers to.
The spectrum of host cells a virus can infect
A virus’s host range is determined by the specific receptors it targets on host cells.
What are prions?
No nucleic acid, misfold of protein that causes disease, don’t have RNA or DNA
Prions are infectious agents composed solely of protein, leading to neurodegenerative diseases.
HIV infects what type of cells?
Helper T cells
These cells are crucial for orchestrating the immune response.
Know the various types of white blood cells (WBCs).
Granulocytes: neutrophils (fight bacteria), eosinophils (attack parasites), basophils; Agranulocytes: lymphocytes (immune), monocytes (eat everything)
Each type of WBC has specialized functions in the immune response.
What is a phagosome?
Phagocyte eats pathogen. Traps pathogen
The phagosome is formed during phagocytosis when a pathogen is engulfed by a phagocyte.
What is a phagolysosome?
Phagosome fuses with lysosome. Breaks down and kills pathogen
This fusion allows for the degradation of the engulfed pathogen.
Be familiar with the process of inflammation and all of the players involved.
Capture white blood cell, WBC attach to protein and rolls to inflammation, protein bonds, WBC spreads
Inflammation involves various cells, including macrophages, neutrophils, and cytokines.
How do NK cells identify their target cells and distinguish them from host cells?
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NK cells use inhibitory and activating receptors to recognize stressed or infected cells.
Be familiar with the various types of chemical and physical barriers to infection.
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Barriers include skin, mucous membranes, and secretions like saliva and tears.
Know the function of cytokines.
Chemical messengers that help immune cells communicate
Cytokines play critical roles in regulating immune responses and inflammation.
Be able to distinguish between the components of innate and adaptive immunity.
Innate is fast and first line of response; Adaptive is slower and builds memory for future infection
Innate immunity provides immediate defense, while adaptive immunity has a delayed response but creates long-lasting immunity.
What is opsonization? What is its function?
Where antibodies coat a pathogen to make it easier to phagocytose to help them kill faster
Opsonization enhances the efficiency of phagocytosis by marking pathogens for destruction.
What type of cells phagocytose bacteria and process their macromolecules for antigen presentation?
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Dendritic cells and macrophages are key players in this process.
What is an antigen?
Substance that stimulates immune response
Antigens can be proteins, polysaccharides, or other molecules that the immune system recognizes.
What type of cells secretes antibodies?
B cells recognize antigens then activate and become plasma cells. Plasma then releases antibodies
Plasma cells are the effector form of B cells essential for humoral immunity.
What type of cell coordinates the humoral and cellular immune responses?
Helper T cells
Helper T cells play a pivotal role in activating both B cells and cytotoxic T cells.
What is the function of antigen presenting cells? What is the role of MHC molecules in this process?
Present antigen to T cells to activate immune response; MHC presents to helper T cells
MHC molecules are essential for the recognition of antigens by T cells.
Be familiar with the primary and secondary immune responses.
Primary: slow and weak; Secondary: fast and strong
The secondary response is more robust due to memory cells generated during the primary response.
What are TLRs and what kind of macromolecules do they bind?
Proteins on immune cells that recognize pathogens; They bind to lipids, nucleic acids, and proteins
TLRs are a type of pattern recognition receptor crucial for the innate immune response.
Know EACH STEP of Phagocytosis and what happens during that step!!!
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Phagocytosis involves steps such as recognition, engulfment, formation of the phagosome, fusion with lysosome, and digestion of the pathogen.
