Week 15 Flashcards
___ developed during the primary response provide protective immunity for the first few weeks. This prevents the activation of the adaptive immune response
Antibodies (but the antibody levels decline with age)
What are the 3 types of memory cells
memory B cells
Memory plasma cells
Memory T cells (both central and effector)
When a T cell is activated and proliferates, does it produce more effector T cells or memory cells?
Effector T cells outnumber memory cells
Which, primary effector cells or memory cells have a broad antigen response?
Primary effector
Which, primary effector or memory cells are easily activated (the dont require costimulatory signals or cytokines)?
Memory cells
Which, primary effector cells or memory cells must undergo target refinement by somatic hypermutation and class switching?
Primary effector cells
Memory cells may undergo somatic hypermutation
How long can immune memory cells persist for?
Decades
Antibodies are produced at a steady state
The secondary immune response activates ___ but inhibits ___. Why?
Memory B cells
Naive B cells
It does this so that energy is only spent producing the high-affinity IgGs instead of spending unnecessary energy
Activated memory B cells replicate into ___ and ___
Plasma cells
More memory cells
True or false… memory T cells do not require CD-28 co-stimulation
True, they do not
Describe how highly mutable pathogens erode immune memory
If first viral infection is ABCD, then later you are infected with ABCE, the ABC memory cells inhibit the naive B cells to produce memory against the E antigen.
Name 7 different types of vaccines
Live-attenuated
Inactivated
Subunit
Conjugate
Toxoid
DNA
Recombinant vector
What was the first live attenuated virus vaccine? Explain how live attenuated vaccines work?
Cowpox
This is a virus raised in a different species. For example, there are some similarities in the antigens of cowpox and smallpox viruses. When you are infected with a smallpox virus, the cowpox antibodies will neutralize it
What is an attenuated virus (not live)?
Pathogenic human virus is isolated, then grown in another species. The virus gains mutations that allow it to infect the other species. Then, the mutated virus is used for a vaccine as it shares viral components with the pathogen but is unable to infect human host
Define adjuvant
A compound that incites an adaptive immune response
Explain how adjuvants can be used to broaden vaccine targets and improve efficacy
If the adjuvant is paired with a typically non-reactive antigen, it enhances the immune response so that it recognizes the antigen as pathogenic
Many vaccines include adjuvants
In regards to recombinant protein vaccines… normally bacterial ____ binds factor ___ to inactivate ___ deposited on the bacterial surface. However, in the presence of specific anti-___, ___ cannot bind factor ___, causing ___ to be fixed and target the bacteira for destruction
Lipoprotein fHbp
H
C3b
FHbp
FHbp
H
C3b
Name 5 ways pathogens can evade the immune system
Stereotype diversity
Antigenic drift
Antigenic shift
Gene conversion
Latency
Name 6 ways pathogens can subvert (take advantage of) the immune system
Endocytic hijacking
Protein mimicry
Humoral inhibition
Inflammation inhibition
Immunosuppression
Superantigens
What is stereotype diversity and how can it allow pathogens to evade the immune system?
A serotype is an antigenically different strain of the same pathogen.
This means that you can be infected with one serotype of a bacteria, but then be infected with another serotype of the same species, giving you the same infection. You must develop completely new antibodies for the new serotype
True or false… stereotypes are formed from high mutation
False! Serotypes have high genetic variability, they are not necessarily due to mutations.
These are useful for tracking outbreaks
What is antigenic drift and how does it allow pathogens to evade the immune system?
Antigenic drift - mutation in the viral genome driven by selective pressure as the virus infects a population
Viral genomes are highly mutable, thus are tied to memory erosion
Antigenic drifts are responsible for viral ___ whereas antigenic shifts are responsible for viral ___
Epidemics
Pandemics
What is an antigenic shift?
Genetic recombination that leads to significant change in viral antigens.
Usually involves recombination with multiple species (bird flu, swine flu, human flu).
What is gene conversion and how does it allow pathogens to evade the immune system?
VSG (variable surface glycoprotein) is altered by trypanosomes to evade antibodies. V
VSG genes are rearranged to express one dominant VSG at a time
What is latency?
A viral dormant state in host tissue
This allows the virus to persist with a reduced viral load and with an absent/reduced interferon response and MHC-1 expression.
Also allows NK and CD8 T cell evasion
What are some common viruses with latent periods?
Cytomegalovirus
Varicella zoster
Epstein Barr
Herpes
Paroviruses
Adenoviruses
What is endocytic hijacking? How is it used to subvert the immune system?
Utilizes endocytosis to enter cells. Here, it prevents prevents lysosome fusion, escapes the phagosome, or survive the autolysosomal envionrment of lysosome
What is antigen mimicry? How is it used to subvert the immune system? What pathogens do this commonly?
Pathogens coat themselves with host proteins to evade the immune system (since it uses host factors, it is considered subversion)
Worms do this a lot
-surface antigens are regularly shed
What are superantigens? How are they used to subvert the immune system?
It binds to MHC 2, so that when it binds to TCR it activates the T cell, yet hides the antigen. This causes an enormous, nonspecific CD4 response.
- this can lead to autoimmunity
- will also inactivate antibodies and complement
What bacteria have superantigens?
Staphylococcus
Streptococcus
By binding ___ to ___ and ___, it prevents the host from recognizing the Fc fragment of antibodies, preventing phagocytosis. Thus the pathogen subverts the immune system
SSLP7
IgA
C5.
What is primary immunodeficiency?
Genetically caused immune system deficiency
can be dominant, recessive, X-linked
What is secondary immunodeficiency? What can cause it?
Immune deficiency caused by environmental factors
Caused by... Chronic disease Immunosuppressive drugs Viral (HIV) Environmental toxins
What is an example of an X-linked immunodeficiency disorder? Describe it.
Agammaglobulinemia
BTK (bruton’s tyrosine kinase is necessary for B cell signaling
BTK on the X chromosome
BTK negative males or BTK homozygous negative females do not develop B cells
Note that heterozygous females will have less B cell development, but not noticibly, they are carriers
What are the 5 classes of primary immunodeficiency ? What percentage of primariy immunodeficieny are of each type?
Humoral immunity - 60%
Cellular immunity - 10%
Combined - 20%
Phagocytic cells - 10%
Complement - <2%
Name four examples of primary cellular immunodeficiencies.
Digeorge syndrome
ZAP-70 deficiency
X-linked lymphoproliferative syndrom
Chronic mucocutaneous candidiasis
Name three examples of phagocytic immunodeficiencies
Chronic granulomatic disease
Leukocyte adhesion deficeincy
Chediak-higashi syndrome
In the immune response to HIV, you see a spike in the level of virus within the 4-8 weeks. Then it goes down, fluctuating for a while, but then it rises up again after how long?
2-12 years
Name the three bacteria that cause STDs
Gonorrhea
Syphilis
Chlamydia
Name one protozoan that causes an STD
Trichomonas vaginalis
Name two Arthropoda that cause STDs
Lice
Scabies
Name three viruses that cause STDs
HIV
HPV
HSV
Name 7 syndromes associated with STDs
Urethritis
Cervicitis
Genital ulcers
Epididymititis
Procititis
Vaginitis
Pelvic inflammatory disease (PID)
What three groups of people get screened for STDs?
People who have had sexual contacts of persons with proven STDs
Symptomatic persons
Persons concerned about having an STD
What is urethritis?
Visible drip from the penis or WBCs seen on a urethral gram stain
What is cervicitis?
Vaginal discharge or friable cervix on exam
Asymptomatic infections are common in both sexes (neither urethritis nor cervicitis)
Chlamydia is most prominent in what population?
Young women in urban areas
What is the most common reportable STD in utah?
Chlamydia trachomatis
What is the epidemiology of mycoplasma genitalia?
Urethritis, cervicitis, PID, endometritis
How do you diagnose gonorrhea for males and females?
Symptoms: white/green/grey purulent discharge, can disseminate
Male: urethral gram stain, nucleic acid amplification testing
Female: nucleic acid amplification testing
True or false… you only do a gram stain for males for gonorrhea
True
Is gonorrhea more prevalent in males for females?
Males
What are two symptoms from STDs that can cause infertility?
Epididysis - males
PID - females
What are the symptoms of PID (pelvic inflammatory disease)?
Vaginal discharge
Cervical motion tenderness
Uterine tenderness
Adnexal tenderness
True or false… PID is an underdiagnosed syndrome
True, many cases are missed and therefore go untreated often with serious consequences.
What is bacterial vaginosis?
White vaginal discharge
Presence of clue cells
PH>4.5
Frisky odor with KOH
What are the symptoms of genital herpes? How do you diagnose it?
Bumps/blisters
Dysuria
Vaginitis
PCR with typing as HSV-1 or HSV-2
Syphilis is caused by ___. Most cases are __ patients that are ___+. How do you diagnose it?
Treponema pallidum
MSM
HIV
Diagnosis - unculturable agent!
What is secondary syphilis?
Syphilis can disseminate to other parts of the body causes a rash (spots on palms).
Note that it is still contagious!
What is another name for HHV-8?
Kaposi’s sarcoma herpesvirus
HHV-6 creates a specific pattern called ___
Roseola
Primary latency of HHV6 and HHV7 reside in ___
CD4 lymphocytes
Kaposi’s sarcoma (HHV-___) primary infection via ___ contact, especially in ___. Primary infection is ___.
8
Sexual
Homosexual males
Asymptomatic
What does the primary infection look like for HSV-1
80% are asymptomatic
Occurs at a young age
In the case of symptomatic primary HSV-1 infections, age affects the clinical presentation. Describe this difference
Young = gingivostomatitis
18+ = pharyngotonsillitis
Describe acute herpetic gingivostomatitis
Primary HSV-1 infection
90% due to HSV-1
Most cases occur before age 5
Both movable and attached oral mucosa affected
Affected mucosa develops pinhead vesicles. Rapidly collapse and form small, red lesions. Initial lesions enlarge and develop central areas of ulceration covered by yellow fibrin. Adjacent ulceration coalesce
Describe primary herpes- pharyngotonsillitis
Initial symptoms - sore throat, fever, headache
Numerous small vesicles develop on tonsils posterior pharynx. Rapidly rupture to form shallow coalesce. Diffuse grey-yellow exudate forms
Can be due to HSV-1 or HSV-2
Describe recurrent herpes simplex
AKA secondary herpes
Can occur anywhere along the surface epithelium supplied by the involved ganglion
Most common site of recurrence for HSV-1 is vermilion border
Recurrent herpes simplex intraoral lesions almost always occur where?
Keratinized, bound mucosa
Symptoms are less intense
What are the histopathology features of HSV?
Multinucleation
Ballooning degeneration
Tzanck cells
What does it mean If you see shingles at the tip of the nose?
It is a sign that ocular infection may occur
What is Ramsay hunt syndrome? What is it caused by?
Cutaneous lesions of the external auditory canal. May involve facial paralysis, hearing deficits, vertigo
Caused by VSV (shingles)
What virus causes infectious mononucleosis?
EBV
What kind of virus may cause herpangina, hand-foot-and-mouth disease, or acute lymphonodular pharyngitis
Coxsackie virus
Which is a type of enterovirus
What virus causes rubeola (measles)?
Paramyxovirus
Which hypersensitivity reactions are humoral and which are cell-mediated?
Humoral - 1, 2, 3
Cell-mediated - 4
True or false.. hypersensitivity reactions are mutually exclusive, meaning that you only have one type of reaction per allergin
False, they cross over
As part of a type 1 hypersensitivity reaction, ___ are Th2 effectors in parasite immunity
Granulocytes
In a type 1 hypersensitivty reaction, ____ degranulation drives inflammation. It’s toxic mediators are ___ and ___which function to…
Mast cell
Histamine
Heparin
Poison parasites, increase vasculature permeability, cause smooth muscle contraction (it increases fluid secretion and peristalsis in the GI tract, decreases diameter in airways, and increases blood flow)
True or false… Eosinophils degranulation is toxic. They are activated/recruited by mast cells and Th2 cytokines.
True
What is the hygiene hypothesis?
Reduced early developmental immune pressure causes poor immune education and an inappropriate pathogen identification, leading to allergy and autoimmune disorders
Allergic reactions occur in two phases. Describe these phases
Immediate: occurs within an hour and causes a deep drop in their expiratory flow rate
In the late phase, eosinophils are involved
What are the symptoms of anaphylactic shock?
Due to mast-cell degranulation and release of inflammatory mediators
Causes significant drop in arterial blood pressure, constriction of airways, contraction of smooth muscel in GI tract
___ halts anaphylactic shock
Epinephrine
What is hyposensitization?
Repeated exposure to escalating dosages of allergens to reduce type 1 responses
What is a type 2 hypersensitization reaction?
Antibody-mediated
IgG response to small molecules bound to cell surfaces.
Type ___ hypersensitivity causes newborn hemolytic disease. Describe how.
Rh- mother carries a Rh+ fetus so the mother develops anti-Rh+ IgG. Next pregnancy with Rh+ child is attacked by the anti-Rh+.
Rhogam prevents this from occurring (erythroblastis fatalis)
Describe type 3 hypersensitivity reactions.
Inefficient immune complex clearance.
Complexes are deposited in blood vessels and tissues
Innate inflammatory response
Inflammatory lesions occur (clot formation, fever, skin rash, rheumatoid arthritis)
Type ___ hypersensitivity is considered the delayed type hypersensitivy. It is cell mediated, not humoral. Primarily CD4 and macrophage mediated. Two phases: sensitization and effector
4
Name three keystone pathogens in periodontitis
P. Gingivalis
Treponema denticola
Tannerella forsythia
Type three hypersensitivity involves what two immunoglobulins?
IgG and IgM
True or false… T cells need a costimulatory signal in order to recognize the allergin as pathogenic to create memory
True
