Unit 4 Lec 1 Flashcards
(34 cards)
What are the usual flora that invade the host?
Non-encapsulated bacteria that activate the alternative complement cascade
- Eliminated by PMNs/macrophages
What does the innate immune system do?
Eliminates normal flora or other non pathogens that gain access into the host
What happens if non encapsulated organisms make it into a immuno compromised host?
Example Staph Epidermidis Cause bloodstream infections
- Cause serious human illness
What are antigen specific humoral immunity?
B Lymphocytes and Antibodies
What are antigen non specific humoral immune system?
Acute: PMNs and Complement
Chronic: Macrophages and complement
What are antigen specific cellular immune fighters?
T Lymphocytes
What are antigen non specific cellular immune system fighters?
Macrophages
What are major categories of microbes?
Bacteria (toxigenic extracellular, non toxigenic extracellular, intracellular)
Viruses
Fungi
Parasites (protozoa and helminths)
How do antibodies act on microbial immunity?
Neutralize exotoxins
Neurtralize some viruses and some obligate intracellular bacteria during extracellular phases
What is an example of an intracellular bacteria that is neutralized by antibodies?
Rickettsia
How does antibody oponization work in microbial immunity
Works on extracellular bacteria (helps PMNs and Macrophages)
What is the CD4 T cell job in microbial immunity?
Activate macrophages
- Mostly against facultative and many obligate intracellular bacteria
- Against fungi
- Against protozoa and other Parasite
- Some viruses
What is wrong with IgE fighting alone?
Against protozoa doesnt eliminate pathogens but allows other parts of immune system to come in
How does CD8 T cells act in microbial immunity?
Eliminate most viruses (intracelllar)
Transplants (look like viral infected cells)
Listeria monocytogenes and a few other bacteria (intracellular)
How are potent exotoxins neutralized?
Normally vaccination is needed to protect against potent ones
- Due to being too strong for body to stimulate immune response
- Examples: Diphtheria, tetanus, pertussis, cholera
How do vaccines work?
Use toxoids that are biologically inactive but retain immunogenicity
How do superantigens and some other toxins target the immune system?
Target the immune system to prevent antibody response TSS from (Staph aureus and Strept pyogenes are susceptible to illness even upon recovery
What are some superantigens?
Toxic shock syndrome toxin-1 (TSST-1)
Staphylococcal enterotoxins (SEs) A-X serotypes
Streptococcal pyrogenic exotoxins (SPEs)
A-C, G-L, Streptococcal superantigen and streptococcal mitogenic exotoxin Z
How are T cells activated by Antigen and Superantigen
Normal antigen will activate 1/10,000 T cells (controlled)
Super antigen actiaves up to 50% of T cells (massive cytokines released)
What are Intravenous immunoglobulins used for (IVIG)?
Antibodies taken that are against common exotoxins used for: Kawasaki Syndrome Streptococcal toxic shock Staphylococcal toxic shock Post exposure prevention of hep A
What else is IVIG used for?
Passive protection against super antigens
30k for one treatment so selective use
What are some extracellular bacterial (Ab based immunity)?
Gram +/- cocci Bacillus Clostridium Enterobacteriaecea (except salmonella) Haemophius (otitis media) Helicobacter BORDETELLA Mycoplasma Chlamydia (walking pneumonia) Borrelia Leptospira Rickettsias
What are some intracellular bacteria (T cell based)?
MYCOBACTERIUM SALMONELLA Yersinia Francisella Brucella Rickettsias Legionella Listeria
What are the different types of Fungi?
Dermatophytes (skin) Subcutaneous Systemic Opportunistic Saprophyes
