Immunology #10-11

Antibodies and AntigensII

Ab structure

Fc: Effector function

Fab: Ag binding

Fab: Ag binding

What is the ‘hinge’ good for?

Fc

Ag determinant

Lost by denaturation Gained by denaturation Proteolysis dependent

Anti-phospho-tyrosine Abs

Methods that use Abs

ELISA

IP

Chr.

WB

FACS

Quansys

Staining

ELISA

IP

Chr.

WB

FACS

Methods that use Abs

Staining

ELISA

IP

Chr.

WB

FACS

Methods that use Abs

Staining

ELISA

IP

Chr.

WB

FACS

Methods that use Abs

Staining

ELISA

IP

Chr.

WB

FACS

Methods that use Abs

Staining

Cases

My name is ____ and I’m a 7-year-old male. I injured my leg while playing in the yard. I had no significant past medical history and all of my vaccinations are up-to-date. Several days after the injury, anaerobic cultures of a wound aspirate were found to grow Clostridium tetani. Despite the bacterial presence, I never developed tetanus! Which of the following allowed this? A. Sensitized CD8 lymphocytes capable of killing the bacteria B. Activated macrophages capable of killing the bacteria C. Neutrophil infiltration of the wound with lysosomal enzyme release D. Circulating antibodies that activate complement E. Circulating antibodies that neutralize bacterial products

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Vaccine: formaldehyde-inactivated tetanus toxin

Immediate: Tetanus immune globulin

Tetanospasmin inhibits release of glycine and GABA from inhibitory interneurons.

My name is ____ and I’m a 23-year-old immigrant that gave birth to a term newborn at home. My husband cut the umbilical cord with a kitchen knife. One week later, my baby developed rigidity and spasms. His condition could most likely have been prevented by which of the following? A. Infant vaccination at the time of birth

B. Maternal vaccination during pregnancy

C. Multivitamins during pregnancy D. Peripartum antibiotics to the mother E. Proper infant nutrition after birth

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The protein structure shown on the slide below is most likely to be found in which of the following?

A. Maternal blood B. Fetal blood C. Fetal thymus D. Maternal bone marrow E. Colostrum

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…. Also mucus, tears and saliva.

Interesting: the secretory piece is synthesized by epithelial cells and prevents IgA degradation by secretions

Fetal blood contains maternal lgG that was able to cross the placenta. At approximately 20 weeks of gestation the fetus does have circulating B lymphocytes and some amount of fetal 1gM is detectable in the blood.

Two patients are vaccinated against poliomyelitis. One patient receives the killed vaccine and the other patient receives the live attenuated vaccine. One month after the vaccination, the levels of which of the following poliovirus antibodies will differ most between these patients?

A. Serum IgM B. Serum lgG C. Serum IgA D. Cerebrospinal fluid IgG E. Duodenal IgA

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My name is ____ and I’m a 23-year-old primigravida that came for a routine prenatal check-up at 28 weeks gestation. I have no significant past medical history. After reviewing the results of my laboratory evaluations, my physician rapidly gave me an injection of Rh immunoglobulin.Rh immunoglobulin belongs to which of the following immunoglobulin classes?

A. lgA B. lgG C. lgM D. lgD E. lgE

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maternal lgG anti-Rh antibodies crossing the placenta, entering the fetal circulation, and causing massive hemolysis of fetal erythrocytes.

erythroblastosis fetalis

Treatment: Anti-Rh Ab (Rh0GAM) consists of lgG anti-Rh antibodies and is routinely administered to Rh-negative females.

My name is ___ and I’m a gram-negative bacteria isolated from the blood of a 22-year-old Caucasian female. I produce a protease that splits the IgA molecule at the hinge region. Which of the following is the most likely biological significance of this enzyme? A. It impairs opsonization and phagocytosis B. It promotes intracellular survival C. It impairs complement-mediated cell lysis D. It facilitates mucosal penetration E. It impairs secondary immune response generation  

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This protease is produced by Neisseria gonorrhoeae and

Neisseria meningitidis

Point of interest: Secretory IgA does not act as an opsonin.

My name is ____ and I’m a 7-year-old male is brought to the emergency room with colicky abdominal pain and arthralgias. My stool is positive for occult blood and urinalysis reveals mild proteinuria. I subsequently developed palpable lesions over my lower extremities, which are most likely caused by:

A. Disseminated bacterial infection B. Circulating immune complexes C. IgE-dependent basophil degranulation D. Antibody-dependent cellular cytotoxicity E. Delayed hypersensitivity reaction  

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Henoch Schonlein purpura

IgA production and immune complex formation. Deposition of these IgA immune complexes on blood vessel walls and within the renal mesangium activates complement and leads to inflammation. ‘Leukocytoclastic vasculitis’.

History: In his 1801 book, On Cutaneous Diseases, Heberden described a 5-year-old boy with "bloody points" over the skin of his legs, abdominal pain, bloody stools and urine, and painful subcutaneous edema.

Johan SchönleinEduard Henoch

My name is _____ and I’m an apparently healthy 12-year-old Caucasian male; I came to the clinic after recurrent exposure to a bacterial antigens that resulted in a rapid increase in serum IgG level. My GP explained: “Some immunoglobulin molecules are attached to the surface of macrophages, neutrophils and B lymphocytes.” So I asked her: “Which of the following is the cell attachment site for the immunoglobulin molecule shown on the slide below?” A

BCDE

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My name is ______ and I’m a 34-year-old Caucasian female whose lgG autoantibodies attack an antigen and cause cell lysis after binding the C1 complement component.

Which of the following is the complement binding site for the immunoglobulin molecule shown on the slide below?

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ABCDE

Next lesson:

Another ‘so far’ lesson including:

(A)Small ‘keep-up-with-the-course’ quiz

(B) Extended in-depth topic:

Is [juvenile] type 1 [autoimmune] diabetes a T-cell or B-cell

mediated disease?