Immunology Flashcards by Daniel Guck

What are the 2 viral glycoprotein spikes that bind to the primary CD4 receptor?

Gp120 and gp41

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What are the 2 7-transmembrane G-protein coupled receptors?

CCR5 and CXCR4

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Which receptors are expressed primarily on T cells, and is called a T-trophic virus when using these receptors?

CD4 and CXCR4

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Which receptors are expressed on macrophages, and are called m-trophic when using these receptors?

CD5 and CXCR5

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For viral entry, what does the Gp120 do to CD4 and CCR5 ?

Pulls the virus closer to the cell membrane

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Later, gp120 binds T0 CD4 and CXC4 receptors, and causes a conformational change to expose which marker?

Gp41

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What is the role of Gp41 for viral entry?

Fuses viral and cell membranes –> allows viral RNA to penetrate the cell

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What would happen if you are deficient in CCR5 or CXCR4?

You’re immune to HIV

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What is released into the cell when the HIV virus is uncoating?

+ ssRNA
RT
Integrase
Protease

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What is the role of reverse transcirptase for HIV?

RNA –> DNA

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What does the HIV use to integrate into the host cell DNA?

Integrase

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Which host enzyme transcribes the viral DNA?

RNA polymerase II

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Which cytokine is stimulated for its transcription during extrinsic stimuli, which therefor stimulates gene transcription of the HIV genome, causing the release of viral RNA into the cytoplasm?

IL-2 and its R

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What happens to the viral RNA once it’s inside the cytoplasm?

proteins are synthesized from it

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What is the enzyme that cuts long protein chains into individuals proteins?

Protease

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After sexual transmission, what “tissue” does HIV infect?

MALT

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Which cells mediate the initial stages of HIV infection?

M-trophic cells

CD4/CCR5

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A mutation in the what gene shifts the tropism of HIV to T-trophic, which allows HIV to infect CD4+ T cells?

Gp120

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What reduces the # of Th cells in HIV infections?

Direct HIV-induced cytolysis
Cytotoxic Tc immune cytolysis
Chronic activation in response to the large HIV Ag challenge –> rapid terminal differentiation

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Infected T cells are killed by what 4 mechanisms?

Accumulation of nonintegrated circular DNA copies of genoma
Increased permability of plasma membrane
Syncytia formation
Induction of apoptosis

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What do activated CD4 Th cells release to initiate immune response, which activates macrophages, other T cells, B cells, and NK cells?

Cytokines

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Under what CD4 levels do Ag-specific immune responses not work and humoral response is uncontrolled?

< 200 cells/uL

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What 2 factors cause the outgrowth of opportunistic intracellular infections when CD4 levels get < 200?

Lose activating of macrophages
Delayed type (IV) hypersensitivity

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What are neutralizing antibodies generated against to cause Ab-dependent cellular cytotoxicity response?

Gp120

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What happens to CD8 levels in HIV infections? Why?

They ↓ b/c they require activation by CD4

A reduction in CD8 cells cause the possibility of what type of infections in HIV?

viral

Why does the infeciton of lymphocytes and macrophages is a way for HIV to escape immune control?

inactivation of key element of immune defense

What happens to gp120 for HIV to escape immune control?

Antigenic drift and heavy glycosulation

During what time is stage 1, stage 2, and stage 3 of HIV infections?

Stage 1: 0-24mo Stage 2: 24-65mo Stage 3: 65 onwards

During stage 1 of the HIV infection, which of the following markers peaks from 0-12 months and then drops to low levels? Virus CD4/T-cell count Anti-HIV-1 Ab

Virus

During stage 1 of the HIV infection, which of the following markers fluctuates with a steady decline? Virus CD4/T-cell count Anti-HIV-1 Ab

CD4/T-cell count

During stage 1 of the HIV infection, which of the following markers slowly increases? Virus CD4/T-cell count Anti-HIV-1 Ab

Anti-HIV-1 Ab

During stage 2 of the HIV infection, which of the following markers slowly increases and then drops off at 60mo? Virus CD4/T-cell count Anti-HIV-1 Ab

Anti-HIV-1 Ab

During stage 2 of the HIV infection, which of the following markers stays low through the entire stage? Virus CD4/T-cell count Anti-HIV-1 Ab

Virus

During stage 2 of the HIV infection, which of the following markers still steadily decreases? Virus CD4/T-cell count Anti-HIV-1 Ab

CD4/T-cell count

During stage 3 of the HIV infection, which of the following markers rises sharply? Virus CD4/T-cell count Anti-HIV-1 Ab

Virus

During stage 3 of the HIV infection, which of the following markers still slowly declines? Virus CD4/T-cell count Anti-HIV-1 Ab

CD4/T-cell count

During stage 3 of the HIV infection, which of the following markers continues to decline and then plateau? Virus CD4/T-cell count Anti-HIV-1 Ab

Anti-HIV-1 Ab

At what CD4 level is full blown AIDS?

< 200 cells/mm3

During which stage do u see ARC?

Stage 2

During which stage do u see AIDS dementia?

Stage 3

During which stages do u see chronic lymphadenopathy?

Stages 1-2

True or False: you start to see disease Sx during the middle phase of stage 2.

FALSE. you dont see opportunists until stage 3

What is the initial Sx of HIV infections?

Flu-like

Which class of opportunistic diseases does these bugs belong to for HIV pts? Toxoplasmosis (brain), cryptosporidiosis (GI), isosporiasis (GI)

Protozoal

Which class of opportunistic diseases does these bugs belong to for HIV pts? Candidiasis, PCP, cryptococcosis, Histoplasmosis, Coccidiodomycosis

Fungal

Which class of opportunistic diseases does these bugs belong to for HIV pts? CMV, HSV, EBV, HHV-8

viral

Which class of opportunistic diseases does these bugs belong to for HIV pts? Disseminated Mycobacterium spp, Salmonella speticemia

Bacterial

Which infections do u see in a CD4 count of 500-200?

Oral thrush

Which infections do u see in a CD4 count of 200-100?

PCP, AIDS dementia

Which infections do u see in a CD4 count of <100?

Toxoplasmosis, cryptococcus, cryptosporidiosis

Which infections do u see in a CD4 count of <50?

CMV retinitis, MAI complex, progressive multifocal leukoenceophalopathy, primary CNS lymphoma due to EBV

What is teh test of choice for the montoring of CD4 T cell counts in AIDS pts?

Flow cytometry

What is the gene that reduces cell surface expression of CD4 and MHCI molecules, alters T-cell signalling pathways, regulates the cytotoxicity of the virus, and is required to maintain high viral loads?

Nef gene

True or False: the nef gene appears to be essential for causing the infection to progress to AIDS.

True

This is the form of treatment which is a mixture of drugs with different mechanisms of action that leads to less potential to breed resistnace in HIV pts.

HAART | highly active antiretroviral treatment

This is the class of antiretrovirals that are phosphorylated by cellular enzymes and are incoporated into cDNA by RT to cause DNA chain termination.

Nucleoside Analogue RT inhibitors (NRTI)

This is the class of antiretrovirals that interefere with HIV-1 Gag-Pol polyprotein processing and inhibit the late stage of HIV-1.

NNRT

This is the class of antiretrovirals that block the morphogenesis of the viron by inhibiting the cleavage of proteins and resulting virus is inactive.

Protease inhibitors

This is the class of antiretrovirals that inhbiits binding to the CCR5 co-receptor with a receptor agonist or fusion or viral envelope and cell membrane witha peptide that blocks the action of the gp41 molecule and prevents the intial infection treatment.

Binding and Fusion inhibitors

This is the class of antiretrovirals that inhibits the viral DNA incorporation into the genome.

Integrase inhbitor

This is the leukemia virus that can replicate but cannot transform cells in vitro, and causes cancer after a long latency period of at least 30 years.

HTLV-1

What are the 3 ways u can get HTLV-1?

Blood transfusion Sex breastfeeding

Which cells does the HTLV-1 virus replicate?

CD4 and DTH T cells

What is the protein that HTLV-1 makes that transactivates the celllar genes for th T cell growth factor IL-2 and its receptor which activates growth of infected cells?

Tax protein

What is the HTLV-1 protein that limits tax's activity, promoting cell survival?

HBZ protein

What may happen to the chromosomes in HTLV-1 stimualted cells to cause the transition to leukemia?

Chromosomal abberations and rearrangements in the T cell Ag receptor

Where is HTLV-1 endemic?

Southern Japan (breast milk) Carribean Central Africa African Americans in the SE USA (IV drug use)

Though HTLV-1 infections are typically asymptomatic, what can it progress to in approximately 1/20 people?

ATLL | adult acute T cell lymphocytic leukemia

What are the malignant cells called in ATLL because of pleomorphism and containing lobulated nucleI?

Flower cells

What is the prognosis for ATLL?

Usually fatal within a year

These are antigens that vary between members of the same species.

Alloantigens

This is an immune response that alloantigens provoke.

Alloreaction.

What type of transplants cause Graft-vs-Host (GvH) disease?

Bone marrow

What happens with the grafted bone marrow and the recipient in GvH disease?

Alloreaction from mature T cells in grafted bone marrow that attack and reject the recipients healthy tissue (the foreign T cells start attacking the recipient)

What are the 4 common affected organs in GvH disease?

Skin Liver Lungs Intestine

What are the skin manifestations of GvH disease?

Bright red rash that involves the palms and soles, starts on the face and neck and moves to the trunk and limbs.

What are the GI manifestations of GvH disease?

profuse watery diarrhea, abnormal liver fxn tests

This is self-tissue transferred from 1 body site to another, and is commonly used in burn pts and plastic surgery where some middle-aged woman wants to look like a duck so she gets her butt fat sucked out and injected into her lips.

Autograft

What is the type of graft between genetically identical twins?

Isograft

Which blood type has both A and B Ab;s in the plasma?

What blood type has neither A or B Ab's int he plasma?

What must be the blood type of a mother to cause anemic babies?

Rh-

What type of hypersensitivity rxn is blood transfusion?

Type II

What type of organ rejection occurs within the first 24 hours?

Hyperacute graft rejection.

What must the most have for the graft to cause hyperacute rejection?

pre-existing Ab's

What happens to the grafted tissue in hyperacute rejection?

It's infiltrated with PMNs --> massive blood clots preventing revascularization

How can an individual have pre-exisitng Ab's for allogenic MHC?

Recipients of repeated blood transfusions Women who have had repeat pregancies People who have already had 1 graft

Under what conditon can the mother make Ab's against any patenral HLA allotype expressed by the baby, since normally fetal and maternal cirulations are segregated?

During the trauma of child birth

So if the mom makes Ab's against paternal HLA's, what can happen to future pregnancies? On future organ transplant?

Pregnancies- no effect | Organ transplant- complicate the search for compatible organ transplant

This is the form of graft rejection where within 10 days there is massive infiltration of macrophages and lymphocytes at the site of tissue destruction and activation of Th cells.

Acute graft rejection

What is the test that is used in the event of a donor-recipient that is not a complete mismatch to determin the degree of class II compatibility?

Mixed lymphocyte reaction

In a Mixed lymphocyte reaction, the donor lymphocytes are irradiated and serve as what?

Simulator cells

The simualtor cells from the donor and the reponder lymphocytes from the recipient are mixed together and what happens in a + test?

recipient cells that proliferate indicated a T cell activation, and the greather the MHC difference, the greater the proliferation.

How long after the surgery does a chronic graft rejection take place?

Months-years

What may provote chronic rejection?

viral infection

True or False: use of immunosuppresive drugs has increased short-term survival but nothing can be done to prevent a chronic graft rejection.

True

Immunology Flashcards

(97 cards)