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four Immunology lectures

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What are the five major types of organisms (although one is not technically alive) that cause infectious disease?
Virus, bacteria, fungus, worms, protist
What strategies do pathogens use to evade the immune system
Use cell receptor or adhesion molecules, hide intracellular, change antigens, mimic cell surface
Describe viral diseases including influenza, SARS, and West Nile.
Viral diseases require a host cell to replicate and they are often prone to error during replication. There is usually facile transmission or latency. Influenza has caused huge epidemics in the past. It is a viral infection of the respiratory tract. The virus is made up of a lipid bilayer from the host cell and dependent on two very important proteins: hemagglutinin, H (helps attach to host cell) and neuraminidase, N(helps detach from the host cells) there are minor variations due to mutations (antigenic drift) in the H and N which accounts for why there is a different flu every season and when there is a new. New suptypes of H and N it can cause major epidemics. SARS sever acute respiratory syndrome, spread from human to human, type of virus from civet or bat
How do bacteria evade the immune system?
Bacteria secrete adhesion molecules, cleave IgA antibody, have highly variable surface antigens, and some can inactivate complement
Describe tuberculosis and diphtheria.
Diptheria: much of the symptoms caused by toxin- cause neural and cardiac damage. Can be immunized from toxoid. TB:1/3 of the world is infected, multiply in macrophages, TH cells recruit macrophages to wall off the bacteria in granuloma in lungs. It’s a reemergin g disease to antibiotic resistance.
Why are protist diseases more difficult to treat than bacterial/viral diseases?
They are eukaryotes and their cell surface molecules are more similar to humans than virus and bacterial cells. They may be intracellular (use CTLs) or be in the blood stream (use antibodies
Describe malaria and African sleeping sickness.
Malaria is spread by a specific sp. Of mosquito, effects 10% of the world, migrates to the liver through the blood in 30 minutes and matures to infect RBCs, which then burst. African sleeping sickness multiplies in the blood stream and then moves into the nervous system. It has a variant surface glycoprotein antigen to help it evade the immune system.
What are example fungal and helminth diseases?
Ringworm, athletes foot, ascaris
Descrie the history of vaccination, including variolation, Jenner, and Pasteur.
Variolation was the deliberate infection with smallpox with the dried pustules leading to a milder form of the disease. Jenner discovered the first vaccine against smallpox by inoculating a boy with cowpox and found that when he was exposed to smallpox he didn’t get it. Pasteur coined the term ‘vaccine’ and made cholera, rabies, anthrax, and rabies vaccines.
What is an ideal vaccine?
Ideal vaccines would be one dose that activates memory cells and is affordable, heat stable, have a mucosal route, and if it was a quick onset would activate B cells and latent would activate T cells.
What is passive immunity and why would it be used? Give examples.
It is the transfer of active humoral immunity in the form of readymade antibodies- it occurs naturally from mother to fetus, passive immunity is used through breast feeding by transferring antibodies to diphtheria, tetanus, polio, and mumps. Snake antivenom is a form of passive immunity.
What is herd immunity?
Not 100% effective but the chance of coming in contact with infected is small
Know at least 5 of the recommended child/teen vaccines.
Hepatitis A and B, DPY, Polio, MMR, HPV
What are the advantages/disadvantages of the five types of vaccine?
I.Live: adv.- growth in host=robust response, mult. epitopes, often one dose /dis.-tiny chance it reverts to virulent form II.Inactivated vaccines adv-. More safe and stable/dis.- repeated boosters and mostly B cell response III.Subunit vaccines are very safe but have few epitopes IV. Conjugate vaccines V. Recombinant vector vaccines experimental
What are primary and secondary immunodeficiencies
Primary- present at birth/ secondary- acquired later in life
Describe lymphoid deficiencies including SCID.
Involve both B and T cells- if B then you get recurrent bacterial infections, if T then you get recurrent viral and fungal infections and decreased B cell activation.Severe combined immunodeficiency- low t-cells, no thymus
Describe myeloid deficiencies including LAD.
Affect innate immunity- phagocytes and leukocytes. Neutropenia- reduction in neutrophils, frequent infections. LAD- leukocyte adhesion deficiency- integrins mutated, limits extravasation of neutrophils
What is the difference between HIV and AIDS?
HIV is the virus that causes acquired immunodeficiency syndrome
How many are infected in the US and the world each day?
150 a day in US and 14,000 in the world
Which countries are experiencing a large problem in population structure because of HIV?
Botswana, Lesotho, Namibia, S Africa, Swaiziland, Zambia, Zimbabwe
How is HIV transmitted?
Blood, sex, mother to fetus
Describe HIV infection of a cell and replication.
Two important proteins- gp41 and gp120, gp120 binds to target cell, gp41 helps fusion, fusion of membranes occurs, entry into cell. The virus enters cell and is reverse transcribed into DNA provirus, which drives transcription of new viruses or integrates into genome of host
What is SIV?
Simian Immunodeficiency Virus
Describe the progress of an HIV infection over time
Lymph node degrades, Helper T and CTLs decrease, B cells don’t proliferate, cytokines shifted towards TH2. Acute phase:high viral load and flu-like symptoms, ends with seroconversion; Chronic phase: no symptoms, slow T cell decrease;AIDS:high viral load, multiple opportunistic infections
How is HIV treated?
Azidothymidine (AZT), Highly active anti-retroviral therapy (HAART) a drug cocktail that costs over $15,000 per yr
Why is a vaccine difficult?
HIV is highly variable within each human, HIV can remain latent for years, attenuated HIV would have safety issues
How many are affected by cancer
1 in 3 will have cancer
Describe the progression of cancer.
Tumor cell (initial cancerous cell), benign tumor (clones that stay compact), Invasive tumor (cancer cells invade local tissues), metastasis (cancer cells invade other parts of body
What are the major types of cancer?
Carcinoma (endo/ecto derm), sarcoma (mesodermal-bone or fat), lymphoma (HSC tissues-solid), leukemia (HSC, in blood)
How does a cell become cancerous?
If normal cells stop dividing, by transformation by chemical, radiation, or viral mutagens, of changed gene
Give examples of commonly mutated genes in cancer.
Oncogenes- always on in cancer, tumor suppressor genes- always off in cancer, apoptic pathways- always off
Describe the antigens used by the immune system to detect cancer.
Tumor specific transplantation antigens (TSTA)- unique to tumor cells, result from mutations giving altered proteins; Tumor associated transplantation antigens (TATA)- not unique to tumor cells, high levels of normally low level protein, adult expression of oncofetal gene
What are oncofetal antigens?
Embryonic antigens expressed in adults- embryonic blood serum is found in liver cancers; embryonic cell adhesion is found in colorectal cancer
Why is the HPV vaccine for cervical cancer controversial?
Bc its given to children before they are sexually active and critics are concerned kids will have sex at a younger age if they are vaccinated for an STD⬦
How do tumors evade the immune system?
Shut down class I MHC, shut down B7 resulting in anergy
How is cancer treated by immunotherapy?
Turn on B7, turn up APCs, cytokine therapy, used naked or tagged antibodies

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emmurphy

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