Immunology Flashcards
Primary immune deficiency
inherited cause of immune compramise
Secondary immune deficiency
due to any other cause e.g. infection (HIV), malignancy, mmalnutrition, drugs (steroids)
Physiological immune deficiency
- neonates
- pregnancy
- old age
Constitutive physical barriers of the immune system (3)
- commensal bacteria
- mucous surfaces
- epithelial barrier
Deficiency of epithelial barrier?
Burns - high risk of infection
Deficiency of mucosal barriers?
- organs affected (2)
- genetic risk factor
IgA deficiency
- lungs, GI tracts - recurrent infections
- caucasian population
Deficiency of commensal bacteria?
- when
- common infections (2)
- after broad spectrum Abx
1) candida albicans
2) C.diff
Cells of innate immune system (7)
- Macrophages
- neutrophils
- eosinophils
- monocytes
- basophils
- NK cells
- dendritic cells
How the innate immune system works (7)
- Innate immune cells are produced in bone marrow, and circulate in blood to be able to migrate to tissues
- cytokines and chemokines detect site of infection and activate endothelium
- Toll-like and Mannose recpetors detect pathogen at infection site
- PAMPs recognise pathogen by responding to proteins on their bacterial sugars
- Fc receptors recognise immune complexes
- inflammatory chemokines and cytokines recruit phagocyte by
a) increasing vascular permeability
b) attracting phagocytes - Oxidative and Non-oxidative killing of pathogen
Oxidative Killing
mediated by reactive oxygen species (superoxides and hydrogen peroxide) generated by action of the NADPH oxidase complex
Non-oxidative killing
mediated by bacteriocidal enzymes such as lysozyme
the lysosome and phagocyte come together to form a phagolysosome
Opsonisation
- what
- mediators
“making the pathogen tasty”
binding of pathogen and phagocyte in order to kill pathogen
facilitated by opsonin
mediated by antibodies, Fc receptors and acute phase proteins e.g. CRP
Common bacterial pathogens in recurrent infections? (2)
- staph aureus
2. mycobacteria
Common fungal pathogens in recurrent infections? (2)
- C.albicans
2. Aspergillus
Types of phagocyte deficiency (3)
- recruitment of phagocytes
- find & catch organism
- kill organism
Reticular Dysgenesis
- what
- inheritance pattern
- enzyme mutation
- lab findings
- outcome
- Severe form of Severe Combined Immunodeficiency (SCID)
- failure of stem cells to differentiate down myeloid/lymphoid lineage leading to a complete absence of granulocytes
- autosomal recessive
- adenylate kinase 2 (AK2)
- absolute deficiency in neutrophils, leukocytes, monocytes, platelets
- fatal without BMT
Kostmann Syndrome
- what
- inheritance pattern
- mutation
- Nitroblue test of oxidative killing (NBT)
- neutrophil count
- leukocyte adhesion markers
- severe congenital neutropenia
- autosomal recessive
- HAX1 protein
- NBT neg
- absent neutrophil count
- leukocyte adhesion markers NORM
Cyclic Neutropenia
- what
- inheritance pattern
- mutation
- cyclic neutropenia every 4-6weeks
- autosomal dominant
- neutrophil elastase ELA-2
Leukocyte Adhesion Deficiency LAD1
- what
- mutation
- presentation
- lab findings
- treatment
- failure to express leukocyte adhesion markers therefore neutrophils are unable to get to site of infection
- B-2 integrin subunit of CD18 in LAD1
- Neonatal bacterial infection
- HIGH neutrophil count
- bone marrow transplant
LAD2
- rare
- associated with
a) growth restriction
b) mental retardation
Chronic Granulomatous Disease
- pathophysiology (5)
- investigation
- inheritance pattern
- deficiency in NADPH oxidase
- inability to generate oxygen free radical s
- excessive inflammation due to high neutrophil/macrophage recruitment
- granuloma formation
- lymphadenopathy + hepatosplenomegaly
- Nitroblue test of oxidative killing (NBT) - abnormal
Dihydrorhodamine test - abnormal - x-linked
IFN gamma receptor deficiency
- what
- cytokines involved
- outcome
- defect of interaction between macrophages and other cells (T cells)
- IL12 & IFNgamma
- susceptibility to mycobacterial infections, salmonella, TB and GBS
Common infections associated with chronic Granulomatous Disease (7)
PLACESS Pseudomonas Listeria Asperigillus Candida E coli Staph aureus Serratia
Inflammatory cytokines (4)
IL-1
IL-12
TNF
IL-6
Non-inflammatory cytokines (2)
IL-10
TGF-beta
Neutrophil
Polymorphonuclear cells capable of phagocytosing pathogens and killing by oxidative and non-oxidative mechanisms
NKC
Lymphocytes that express inhibitory receptors capable of recognising HLA class I molecules and have cytotoxic capacity
Dendritic Cell
Immature cells are adapted for pathogen recognition and uptake whilst mature cells are adapted for antigen presentation to prime T cells
Macrophage
Derived from monocytes and resident in peripheral tissues
Complement Classical Pathway
- which proteins?
- main protein and function
- dependant on?
- causes
- C1, C2, C4
- C1 provides binding site on Ab
- immune response
- formation of immune complexes Ab/antigen
MBL Pathway
- which proteins
- protein function
- causes
- MBL
- MBL direct binding to microbial carbohydrates
- links in classical pathway via C2, C4
Complement Alternative Pathway
- which proteins?
- protein function
- factors involved
- C3
- C3 directly binds to bacterial cell wall
- B, I , P
C3
Cleavage of this protein may be triggered via the classical, MBL or alternative pathways
C1
Binding of immune complexes to this protein triggers the classical pathway of complement activation
C9
Part of the final common pathway resulting in the generation of the membrane attack complex
MBL
Binds to microbial surface carbohydrates to activate the complement cascade in an immune complex independent manner
Classical pathway deficiency
- common protein affected
- association
- why
- test
- C2
- SLE
- Classical pathway is repsonsible fro removing immune complexes, these build up in SLE in skin, joints, kidneys
- CH50
MBL deficiency
- common or rare?
- significant when?
- very common (30%)
- significant is another immune impairment present e.g. chemo/HIV
Alternative pathway deficiency
- common factor involved
- susceptible to infections caused by which microbes? (4)
- test
- Factor B
- ENCAPSULATED bacteria
1. N menigitides
2. Strep pneumoniae
3. H influenzae
4. GBS - AP50
Terminal Pathway Deficiency
- what
- why
- associations (2)
- susceptible to infections? (4)
- tests
- lack of C3, 5, 6, 7, 8, 9 so severe susceptibility to bacterial infections
- cannot form MAC to kill bacteria
- glomerulonephritis
- connective tissue disease
- glomerulonephritis
- ENCAPSULATED bacteria
1. N menigitides
2. Strep pneumoniae
3. H influenzae
4. GBS - CH50 & AP50
Membranoproliferative nephritis and bacterial infections
C3 deficiency with presence of nephritic factor
Meningococcus meningitis with family history of sibling dying of same condition aged 6
C9 deficiency
Severe childhood onset SLE with normal levels of C3 and C4
C1q deficiency
Recurrent infections when receiving chemotherapy but previously well
MBL deficiency
Characteristics of the adaptive immune system (4)
- wide repertoire of antigen receptors
- specificity
- clonal expansion
- immunological memory
Primary lymphoid tissues (2)
- Bone marrow
2. Thymus
Secondary lymphoid tissue (3)
1, Lymph nodes
- MALT
- Spleen
Where does B cell maturation occur?
Bone marrow
Where does T cell maturation occur?
Thymus
T Cell Maturation (5)
- arise from haemopoetic stem cells
- exported as immature cells to the THYMUS
- Mature T lymphocytes leave thymus and enter circulation
- Reside in secondary lymphoid tissue
- T cell receptor interacts with HLA molecule on APC
Which HLA Class do CD4+ T cells interact with?
Class II
Which HLA Class so CD8+ T cells interact with?
Class I
Three types of T Cell tolerance ?
- Low affinity for HLA - to avoid inadequate reactivity
- Intermediate affinity for HLA - positive selection for 10% cells
- High affinity for HLA - to avoid autoreactivity
CD4+ T Cell subsets (5)
- Th1
- Th17
- Treg
- TFh
- Th2
Th1 (2)
- Help CD8 T cells and macrophages
2. Subset of cells that express CD4 and secrete IFN gamma and IL-2
Th17
Help neutrophil recruitment
Enhance generation autoantibodies
Treg (2)
- Regulate IL-10/TGF beta expressing
2. Subset of lymphocytes that express Foxp3 and CD25
TFh (2)
- Support the germinal centre on the lymph node
- Play an important role in promoting germinal centre reactions and differentiation of B cells into IgG and IgA secreting plasma cells
Th2
T helper cells
CD8+ T cells (5)
- cytotoxic T cells
- recognise HLA Class I peptides
- kill cells directly
- produce cytokines INFgamma and TNFalpha
- important defence against viral infections & tumours
CD8+ T Cells
Express receptors that recognise peptides usually derived from intracellular proteins and expressed on HLA class I molecules
Antigen encounter in germinal centre of LN (4)
- CD4+ T cell is primed by dendritic cell
- CD4+ T cell helps IgM B cell differentiation
- B cell proliferation
- Isotype switching to IgG, IgE, IgA
What area of the immunoglobulin recognises the antigen?
Fab antigen binding region on both the heavy and light chain
What is the effector area of the immunoglobulin?
Fc region of the heavy chain
Antibody function (3)
- identification of toxins and pathogens - Fab
- Interaction with other immune cells to remove pathogens - Fc
- Defence against bacteria
B Cell Memory (4)
- reduced time between antigen exposure and antibody production
- increased titre of antibody produced
- IgG antibodies dominate
- can be independant of CD4+ T cells
Pre B Cells
Exist within the bone marrow and develop from haematopoietic stem cells
IgA
Divalent antibody present within mucous which helps provide a constitutive barrier to infection
IgG secreting plasma cells
Cell dependent on the presence of CD4 T cell help for generation
IgM secreting plasma cells
Are generated rapidly following antigen recognition and are not dependent on CD4 T cell help
Common infections in Lymphocyte deficiencies
- bacterial (2)
- fungal (2)
- viral
- malignancy
Bacterial 1) mycoplasma 2) salmonella Fungal 1) Pneumocystis 2) Crytosporidium Viral - CMV Early malignancy
Age of presentation of SCID and WHY?
> 3/12
Prior to this protected by maternal IgG that CAN cross placenta
Most common form of SCID?
Mutation?
Pathogenesis (4)
X-linked
IL-2 receptor
1. IL-2 receptor shared by numerous interleukins
2. Inability to respond to cytokines
3. T Cell and NK cell development is arrested
4. Formation of immature B cells
Di George syndrome
- what
- symptoms
- chromosomal abnormality
- laboratory findings
- developmental defect of pharyngeal pouch C- cardiac abnormalities A- abnormal facies T - thymic aplasia C- cleft palate H - hypocalcemia 22 - 22q11.2 deletion - reduced numbers of T cells due to thymic immaturity
Most common type of Bare Lymphocyte Syndrome?
Type II
Regulatory proteins involved in BLS? (2)
- Regulatory Factor X
2. Class II transactivator
BLS Type I
defect in expression of MHC Class I therefore profound deficiency in CD8+ T Cells
BLS Type II
defect in expression of MHC Class II therefore profound deficiency in CD4+ T Cells
Association with BLS?
Sclerosing cholangitis
Severe recurrent infections from 3 months,CD4 and CD8 T cells absent, B cell present, IgM present, IgA and IgG absent
X-linked SCID
Young adult with chronic infection with Mycobacterium marinum
IFN gamma receptor deficiency
Recurrent infections in childhood, abnormal facial features, congenital heart disease, normal B cells, low T cells, low IgA and IgG
Di George syndrome
6 month baby with two recent serious bacterial infections. T cells present – but only CD8+ population. B cells present. IgM present but IgG absent
Bare Lymphocyte Syndrome Type II
Bruton’s hypogammaglobulinaemia
- inheritance pattern
- defect
- lab finding
X-linked
B cell tyrosine kinase
Lack of mature B cells
Selective IgA Deficiency
- who
- what infections? (2)
- 70%?
- caucasian
- resp and GI
- asymptomatic
Hyper-IgM Syndrome
- what (2)
- mutations (4)
- lab findings
- who
- common infection
- disruption in T/B Cell communication
- failure of antibody class swtichinh
1. CD40 Ligand
2. CD40
3. AICDA
4. CD154 - HIGH IgM, abesent IgG/IgE/IgA
- boys
- pneumocystis carinii
Common variable immune deficiency
- what
- presentation (3)
- lab findings
- defect in B cell differentiation of unknown cause
1. failure to thrive
2. recurrent infections
3. autoimmune & granulomatous diseasae - LOW IgG/IgE/IgA
Adult with bronchiectasis, recurrent sinusitis and development of atypical SLE
Common variable immune deficiency
Recurrent bacterial infections in a child, episode of pneumocystis pneumonia, high IgM, absent IgA and IgG
X-linked hyper-IgM syndrome due to CD40 ligand mutation
1 year old boy. Recurrent bacterial infections. CD4 and CD8 T cells present. B cells absent, IgG, IgA, IgM absent
Bruton’s hypergammaglobulinaemia
Recurrent respiratory tract infections, absent IgA, normal IgM and IgG
IgA deficiency
Type I hypersensitivity reaction
- immunoglobulin
- process (6)
- how long?
- symptoms (7)
- IgE
1. crosslinking of IgE on mast cells
2. degranulation of mast cells
3. release of histamine
4. recruitment of neutrophils
5. increased blood vessel permeability
6. inflammation - within minutes, up to 2 hours
1. angioedema
2. urticaria
3. rhinoconjunctivits
4. wheeze
5. diarrhoea
6. vomiting
7. anaphylaxis
Anaphylaxis
a severe, systemic allergic reaction
Types of anaphylaxis
- IgE mediated e.g. peanut, penicillin, bites
- Non-IgE mediated e.g. NSAIDs, IV contrast
- both result in mast cell degranulation
Management of Anaphylaxis (8)
ABCDE 100% O2 elevate legs IM Adrenaline 500mcg Inhaled bronchodilators IC Hydrocortisone 100mg IV Chlorphenamine 10mg IV Fluids
Type I Hypersensitivity Reactions (5)
- Atopic dermatitis
- Food allergy
- Oral allergy syndrome
- Allergic rhinitis
- Acute urticaria
Type IV Hypersensitivity
- onset
- mediated
Delayed hypersensitivity
- 24-48 hours
- T Cell mediated
Examples of Type IV Hypersensitivity (4)
- T1DM
- Multiple sclerosis
- RA
- Crohn’s disease
Type II Hypersensitivity
- mediated by
- results in
- IgM IgG
- IgG/IgM reacts with self antigen and results in tissue damage, receptor blockade/activation
Type III Hypersensitivity
- mediated by
- pathphysiology
- association
- examples (4)
- IgG/IgM
- immune complex mediated damage
- underlying Hep C
1. SLE
2. Mixed essential cryoglobinaemia
3. Serum sickness
4. Polyarteritis Nodosa
Serum Sickness
- what
- pathophysiology (4)
- type of hypersensitivity reaction
- Abx
- Symptoms (7)
- Onset
- reaction to proteins in antiserum
1. formation of immune complexes
2. that activate complement and
3. infiltrate vessels causing inflammation
4. small vessel vasculitis - Type III
Sx
rashes
urticaria
arthralgia
lymphadenopathy
fever
malaise
confusion - 7-12 days
Sjogren’s Syndrome
- what
- who (2)
- symptoms (3)
- test
- chronic autoimmune disease against exocrine glands
- M>F >40years
1. dry eyes- xerostomia
2. keratoconjunctivitis sicca
3. parotid or salivary gland enlargement - Schirmer test
IPEX Syndrome
- what
- who (2)
- symptoms 4)
I - immmune dysregulation P - polyendocrinopathy E - enteropathy X - X-linked - male children
Human immunoglobulin therapy
- use
- where from?
- which diseases? (4)
- post exposure prophylaxis
- screened human donors
1. Tetanus
2. Rabies
3. Varicella zoster
4. Primary antibody deficiencies
Anti T Cell monoclonal antibodies
- use (3)
- examples (3)
- during active transplant rejection
- prevention of rejection
- RA if anti-TNF have failed
- Muromonab-CD3
- Basiliximab
- Abatacept
Use of recombinant cytokines (2)
- examples (3)
- boost immune response to cancer
- boost immune response to specific pathogens
IFN alpha
IFN beta
IFN gamma
Uses of IFNalpha (3)
- Hep C
- Karposi’s sarcoma
- CML
Uses of IFNbeta
relapsing MS
Uses of IFNgamma
chronic granulomatous disease
Ipilimubab
- what
- mechanism
- example of use
- immune booster
- blocks CTLA4 to allow T cell activation
- melanoma
Pembrolizumab
- what
- mechanism
- example of use
- immune booster
- blocks PD-1 to allow T cell activation
- melanoma
uses of corticosteroids (5)
- auto-immune
- allergic disorders
- auto-inflammatory disorders
- transplantation
- malignant disease
Mechanism of corticosteroids (4)
- inhibits phospholipase A2
- Reduces prostaglandin synthesis
- Inhibits phagocyte migration and function
- Inhibits lymphocyte function and promotes apoptosis
Side effects of corticosteroids (10)
C - cataracts U - ulcers S - skin; bruising, thinning, striae H - hypertension, hirsuitism, hyperglycemia I - infection N - necrosis of femoral head G - glaucoma O - obesity, osteoporosis I - immunosuppression D - diabetes
Anti-proliferative agents
- target
- cells affected
- examples (3)
- side effects (4)
- inhibit DNA synthesis
- rapid turnover
1. Cyclophosphamide
2. Mycophenolate mofetil
3. Azathioprine
- Bone marrow suppression
- infection
- malignancy
- teratogenicity
Cyclophosphamide
- mechanism of action
- uses (2)
- alkylates guanine base of DNA
1. multi-system connective tissue disease
2. vasculitis with end-organ damage
Azathioprine
- mechanism of action
- uses (3)
- side effect
- blocks de novo purine synthesis
1. auto-immune disease
2. auto-inflammatory disease
3. transplantation - hepatotoxicity
Myclophenolate mofetil
- mechanism of action
- uses (3)
- side effects (2)
- blocks de novo nucleotide synthesis
1. Autoimmune disease
2. vasculitis
3. transplantation
- bone marrow suppression
- herpes
Plasmapharesis
- what
- uses (3)
- removal of pathogenic antibody by treating patients own plasma and then reinfusing
- type II antibody mediated hypersensitivity reactions
1. Goodpasture’s
2. Myasthenia Gravis
Inhibitors of Cell signalling
- mechanism (2)
- examples (3)
- inhibits calcineurin
- therefore downregulates IL-2 expression
- Tacrolimus
- Ciclosporin
- Sirolimus
Side effects of Ciclosporin (6)
- gingical hypertrophy
- DM
- nephrotoxicity
- neurotoxicity
- hypertension
- dysmorphism
Rituximab
- mechanism of action
- result
- use
Anti-CD20
Decreases B cells
Lymphoma
Methotrexate
- mechanism of action
- result
- uses (3)
- side effects (2)
- inhibitis dihydrofolate reductase DHFR
- decreases DNA synthesis
1. RA
2. psoriasis
3. Crohn’s
- teratotoxicity
- hepatotoxicity
Basiliximab
- mechanism of action
- result
- use
Anti-CD25
Inhibits T cell proliferation
Prophylaxis for allograft rejection
Abatacept
- mechanism of action
- result
- use
CTLA4-Ig fusion protein
Reduces T cell activation
RA
Natalizumab
- mechanism of action
- result
- use (2)
Antibody to alpha4 subunit
Inhibits T cell migration
1. relapsing-remitting MS
2. Crohn’s
Efalizumab
- mechanism of action
- result
- use
Antibody to CD11a
Inhibits T cell migration
Psoriasis
Tocilizumab
- mechanism of action
- result
- use
Antibody to IL-6
Reduces macrophage, T cell and B cell activation
RA
Alemtuzumab
- mechanism of action
- result
- use
Antibody to CD52
Lymphocyte depletion
CLL
Anti-cytokines
- what
- examples (5)
- uses (4)
TNF-alpha
- Infliximab
- Adalimumab
- Certolizumab
- Golimumab
- Etanercept
Uses
- RA
- AS
- Psoriasis
- IBD
Denosumab
- mechanism of action
- result
- use
RANK ligand inhibitor
inhibits RANK mediated osteoclast differentiation
OA
Three stages of Transplant rejection
- Recognition
- Activation
- Effector function
Most relevant proteins in transplant recognition
- ABO blood antigens
2. HLA coded by chromosome 6 on MHC
Where are ABO antigens expressed?
- RBCs
2. endothelial lining of blood vessels in transplanted organ
Where is HLA Class I expressed?
A, B, C
ALL cells
Where is HLA Class II expressed?
DR, DQ, DP
expressed by APCs and cells under stress
What’s special about HLA?
Highly polymorphic as there are hundreds of alleles for each locus so any two people are unlikely to have the same two alleles
Where is most of the variability in HLA?
peptide groove
Maximum number of HLA mismatches allowed in transplantation?
6
Direct recognition?
Donor APC presents antigen and/or MHC to recipient T cells
Acute rejection
Indirect recognition?
Recipient APC presents donor antigen to recipient T cells
Chronic rejection
Phases of transplant rejection (3)
Phase 1 - recognition of foreign antigens
Phase 2 - T cell activation
Phase 3 - effector phase
Effector phase of rejection (5)
- T cells proliferate
- T cells produce cytokines
- Activate CD8+ cells
- Provide help for antibody production
- Recruit phagocytic cells
What type of hypersensitivity reaction is rejection?
Type IV
Symptoms of rejection
- general
- kidney
- liver
- lung
- fever, tenderness
- rise in creatinine, fluid rentention, HTN
- deranged LFTs, coagulopathy
- breathlessness, pulmonary infiltrate
How to investigate transplant rejection?
Biopsy - check for acute cellular reaction
- infiltration of cells
- tubular function
Time scale of acute rejection?
- pathology
weeks - months
cellular infiltrate
Time scale of chronic rejection?
- pathology
months - years
fibrosis & vasculopathy
Prevention of rejection (3)
- AB/HLA matching
- Screening for anti-HLA antibodies
- Immunosuppression
screening for HLA antibodies? (3)
- cytotoxicity assays
- flow cytometry
- solid phase assays
HLA matching is very important in…? (2)
- Kidney
2. BMT
Graft versus host disease?
- onset
- symptoms
donor cells attacks hosts
days-weeks
rash, D&V, bloody stool, jaundice
Treatment of antibody-mediate damage? (2)
- Plasma exchange
2. IVIg
Common opportunistic infections post-transplant? (3)
- CMV
- BK virus
- pneumocystis carini
Post-transplantation’s malignancies? (2)
- Karposi’s sarcoma
2. EBV
What kind of virus is HIV?
RNA retrovirus
HIV Lifecycle (7)
- Targets CD4+ T helper cells
- Reverse transcription & DNA synthesis
- Integration (viral DNA + host DNA)
- viral transcription
- viral protein synthesis
- assembly of virus & release of virus
- maturation
HIV-1 co-receptors used to enter target cells? (2)
CCR5
CXCR4
Transmission of HIV (3)
- Sexual - mucosal surfaces contain dendritic cells
- Vertical - mother to child through birth or via breast milk
- Blood - transfusion, sharing needles
Where does HIV bind to?
gp120- intial binding
gp41 - conformational change
Immune response to HIV-1 (3)
- Innate
- Adaptive
- Aquired
Innate response to HIV (4)
- Non-specific activation of macrophages, NK cells, complement
- stimulation of dendritic cells by TLR
- release of chemokines & cytokines
- inflammation
Adaptive response to HIV
- neutralising antibodies (2)
- non-neutralising antibodies (1)
neutralising 1. anti-gp120 2. anti-gp41
non-neutralising 1. anti-p24 gag IgG
Acquired response to HIV
- which cells?
- chemokines (3)
- how?
CD8+ Tcells
MIP-1a, MIP-1b, RANTES
prevent HIV entry into CD4+ T cells
How does HIV-1 damage the immune response? (5)
- Infected CD4+ T cells are killed by CD8+ T cells
- Infected CD4+ T cells are anergised
- CD4+ T cells are unable to prime CD8+ T cells so T cell cell memory is lost
- Infected monocytes or dendritic cells are killed by the virus
- quasispecies are produced as reverse transcriptase is error-prone
Development from HIV-1 to AIDS?
8-10 years
Prediction of disease progression?
viral load
Rapid progressors - development from HIV-1 to AIDS
2-3 years
Long-term non-progressors?
stable CD4+ counts and no symptoms after 10 years
AIDS CD4+ T cell count?
Screening test fro HIV?
anti-HIV antibody detected by ELISA
Confirmation test by HIV?
Anti-HIV antibody detected by Western Blot
How long is the incubation period to seroconvert?
10 weeks
HIV treatment?
HAART - highly active anti-retroviral therapy
= 2 non-nucelotide reverse transcriptase inhibitors + protease inhibitor
Limitations of HAART? (5)
- doesn’t eradicate latent HIV-1
- fails to restore T cell responses
- high pill burden
- toxicities
- adherence
HAART during pregnancy?
Zidovudine - reduces transmission to newborn from 26% to 8%
8 week vaccinations (7)
- Diphtheria
- Tetanus
- Whooping cough
- Polio
- H.influenzae B
- Pneumococcal
- Rotavirus
1 year vaccinations (4)
- H.influenzae B
- Men C
- Pneumococcal
- MMR
best vaccine?
activate both B and T cell memory
Antigen presenting cells (4)
- Macrophages
- B lymphocyte
- Langerhans cells
- Dendritic cell
Cell mediated response
- t cell
- cytokines involved (3)
Th1 Cell
IL-2, IFN-gamma, TNF
Humoral response
- t cell
- cytokines involved (3)
Th2 cell
IL-4, IL-5, IL-6
T Memory cells
a) central memory cells
- where
- express
- produce
b) effector memory cells
- where
- express
- produce
a) central memory cells
- LNs and tonsils
- CCR7+ CD62L-
- IL-2
b) effector memory cells
- liver, lungs, gut
- CCR7- CD62 low
- IFN-gamma, perforin
Live vaccine
- advantages (2)
- disadvantages (2)
- examples (3)
Ads 1) lifelong immunity 2) cross-reaction against different strains Disads 1) reversion to virulence 2) careful in ID patients Examples - polio, MMR, BCG
Inactivated vaccine
- advantages (4)
- disadvantages (2)
- examples (3)
Ads -1) easy storgae 2) cheaper 3) safe in ID patients 4) no reversion to virulence Disadvs 1) repeated boosters required 2) shorter immunity
Examples - Diphtheria, tetanus, Hep B
Adjuvants used in vaccines?
- why
- example
acts as a depot to increase immune response by slow release of the antigen without altering its specificity
- ALUM, CpG