A pregnant patient’s placenta produces a cytokine that shifts maternal helper T cells away from a Th1 profile to improve fetal survival. Which cytokine is responsible?

IL-4

Because of placental immune biasing during pregnancy, most humans are born with helper T cells skewed toward which cytokine profile?

Th___ cytokines

Th2 cytokines

A child raised with limited microbial exposure later develops multiple environmental allergies. Which concept best explains this association?

A. Molecular mimicry

B. Hygiene hypothesis

C. Epitope spreading

D. Anergy escape

B. Hygiene hypothesis

According to the hygiene hypothesis, early childhood microbial infections tend to bias immune responses toward which helper T-cell subset?

A. Th17 cells

B. Tfh cells

C. Th2 cells

D. Th1 cells

D. Th1 cells

In populations with improved hygiene and fewer childhood infections, which disease pattern is expected to increase?

A. Allergic disease

B. Severe neutropenia

C. Complement deficiency

D. Chronic granulomas

A. Allergic disease

Early exposure to certain allergens is thought to reduce later allergy risk by promoting which immune bias?

A. Th2 polarization

B. Th1 polarization

C. IgE fixation

D. Mast-cell priming

B. Th1 polarization

Which T-cell population helps prevent IgE production against common environmental allergens?

____ ____ cells

Regulatory T cells

A tissue helper T cell is induced to suppress allergic antibody production. What cell type has it most likely become?

____ cell

iTreg cell

An iTreg suppresses allergic sensitization by producing cytokines that redirect antibody class switching. Which cytokine pair is involved?

A. IL-4 and IL-5

B. IL-2 and IL-12

C. IFN-gamma and TNF

D. IL-10 and TGF-beta

D. IL-10 and TGF-beta

In non-atopic individuals, most CD4+ T cells specific for common allergens belong to which population?

A. Th17 cells

B. Regulatory T cells

C. Cytotoxic T cells

D. Follicular T cells

B. Regulatory T cells

A patient has mutant IgE receptors that signal excessively after crosslinking. Which mast-cell cytokine is abnormally increased?

IL-4

Excessive IL-4 secretion from mast cells in an atopic patient would most directly increase production of which antibody class?

IgE

Omalizumab prevents allergic activation by binding which region of IgE?

___ region

Fc region

Omalizumab blocks IgE from binding most directly to which allergy-effector cell?

A. Eosinophils

B. Mast cells

C. Th1 cells

D. Tregs

B. Mast cells

What defines autoimmune disease?

A. Loss of self-tolerance

B. Excessive IgA switching

C. Persistent eosinophilia

D. Failed antigen uptake

A. Loss of self-tolerance

Chronically stimulated self-reactive T cells are normally eliminated after ligation of which surface molecule?

____

Fas

Which tolerance mechanism eliminates chronically stimulated T cells through Fas-mediated signaling?

A. Somatic hypermutation

B. Molecular mimicry

C. Class switching

D. Activation-induced cell death

D. Activation-induced cell death

Molecular mimicry is when a microbe expresses an _____ that resembles a _____ _____ , activating self-reactive _____ .

antigen

host antigen

lymphocytes

Molecular mimicry can activate lymphocytes that had previously failed to respond to which antigen type?

____-____

Self-antigens

A patient develops seasonal allergic rhinitis after exposure to outdoor aeroallergens. Which source most likely triggered hay fever?

A. Mold spores or pollens

B. Animal venoms

C. Indoor endotoxins

D. Bacterial capsules

A. Mold spores or pollens

Compared with hay fever allergens, asthma-triggering allergens are most commonly found in which location?

Indoors

A non-allergic person and an atopic person encounter the same environmental antigen. Which antibody pattern is most likely?

A. IgE versus IgG

B. IgG versus IgE

C. IgA versus IgM

D. IgM versus IgA

B. IgG versus IgE

During initial allergen sensitization, mast cells bind which region of newly produced IgE?

A. Fab region

B. Variable region

C. Hinge region

D. Fc region

D. Fc region

An atopic patient is re-exposed to an allergen after prior sensitization. What event directly initiates mast-cell degranulation?

A. IgE crosslinking

B. IgG opsonization

C. Fas ligation

D. Treg induction

A. IgE crosslinking

Free IgE in blood has approximately what half-life?

A. Two months

B. Two weeks

C. Two days

D. Two hours

C. Two days

When IgE is attached to mast cells, it can persist for approximately how long?

A. Hours

B. Days

C. Weeks

D. Months

D. Months

Which cells mediate the immediate phase of allergic reactions?

_____ cells and _____

Mast cells and basophils

Which allergic effector cell is primarily stationed in tissues?

Mast cell

Which allergic effector cell is primarily found circulating in blood?

Basophil

Which cell type mainly mediates the delayed phase of allergic reactions?

_____

Eosinophils

In chronic allergic reactions, T-cell production of which cytokine recruits eosinophils from bone marrow?

IL-5

A germinal center dominated by Th1 cells is most likely to generate B cells producing which antibody class?

IgG

Th1-dominated germinal centers promote IgG class switching through secretion of which cytokine?

IFN-gamma

A germinal center dominated by Th2 cells is most likely to generate B cells producing which antibody class?

IgE

Th2-dominated germinal centers promote allergic antibody production through which cytokines?

A. IL-2 and IL-12

B. IL-10 and TGF-beta

C. IL-4 and IL-5

D. IFN-gamma and TNF

C. IL-4 and IL-5

An atopic patient has recurrent allergic rhinitis and asthma after common environmental exposures. Which helper T-cell subset would be increased?

A. Th1 cells

B. Th2 cells

C. Th17 cells

D. Tfh cells

B. Th2 cells

A Th1 cell secretes TNF during a cellular immune response. Which innate immune cell is most directly activated?

___ ___ cell

NK cell

A Th1 response produces IL-2 during intracellular infection. Which cell populations proliferate in response?

____ cells and ____

NK cells and CTLs

At the maternal-fetal interface, placental cytokines shift helper T cells away from Th1 immunity. Which helper T-cell fate is promoted?

A. Th17 cell

B. Tfh cell

C. Th1 cell

D. Th2 cell

D. Th2 cell

An infant’s early microbial infection biases later immune responses toward which helper T-cell subset?

A. Th1 cells

B. Th2 cells

C. Tfh cells

D. Treg cells

A. Th1 cells

The composition of the intestinal microbiota is mainly established during which period?

A. First few years

B. Early adolescence

C. Late adulthood

D. Fetal development

A. First few years

A patient has inherited allergy susceptibility involving antigen presentation to CD4 cells. Which gene group is implicated?

A. Class I MHC

B. Class II MHC

C. TCR alpha

D. CD8 coreceptor

B. Class II MHC

An atopic patient has inherited IgE receptor variants that amplify mast-cell signaling. Which cytokine becomes elevated?

A. IL-10

B. IFN-gamma

C. IL-4

D. IL-12

C. IL-4

A patient receives glucocorticoids for severe allergic disease. Which immune effect explains symptom improvement?

Block ____ ____

Block helper cytokines

Glucocorticoids reduce allergic responses partly by lowering helper T-cell cytokines. What downstream B-cell effect follows?

Fewer activated ____ cells

Fewer activated B cells

A patient on chronic glucocorticoids has improved allergies but develops recurrent infections. What adverse immune effect explains this?

A. Weakened immune system

B. Enhanced Th1 immunity

C. Increased complement lysis

D. Excessive IgA secretion

A. Weakened immune system

Which allergy treatment is described as the only approach capable of curing allergies?

A. Omalizumab therapy

B. Glucocorticoid therapy

C. Specific immunotherapy

D. Antihistamine therapy

C. Specific immunotherapy

Specific immunotherapy treats allergy by repeatedly giving which type of exposure?

A. Decreasing allergen doses

B. Increasing allergen doses

C. Single allergen bolus

D. Continuous steroid pulses

B. Increasing allergen doses

Current theory suggests allergen immunotherapy induces regulatory T cells to produce which cytokines?

A. IL-4 and IL-5

B. IFN-gamma and TNF

C. IL-2 and IL-12

D. IL-10 and TGF-beta

D. IL-10 and TGF-beta

An allergy patient develops increased IL-10 after therapy. What outcome would this cytokine most likely promote?

A. Prevent allergic reaction

B. Increase IgE secretion

C. Activate mast cells

D. Recruit eosinophils

A. Prevent allergic reaction

A child has autoimmune lymphoproliferative syndrome with enlarged lymph nodes. What mechanism best explains the disorder?

____ signaling defect

Fas signaling defect

In autoimmune lymphoproliferative syndrome, defective Fas signaling causes which cellular abnormality?

A. B cells die early

B. T cells survive too long

C. NK cells lose cytotoxicity

D. Eosinophils leave marrow

B. T cells survive too long

A patient with Canale-Smith syndrome develops lymphadenopathy and autoantibodies. Which cell type accumulates abnormally?

A. T cells

B. Mast cells

C. Neutrophils

D. Basophils

A. T cells

Which finding is characteristic of autoimmune lymphoproliferative syndrome?

A. Self-reactive antibodies

B. Absent class II MHC

C. Low lymphocyte counts

D. Failed IgE binding

A. Self-reactive antibodies

For autoimmune disease to occur, MHC molecules must be able to present which antigen type?

____ antigen

Self antigen

Which lymphocyte feature is required for autoimmune disease development?

Self-____ ____

Self-reactive receptors

Besides genetic susceptibility and self-reactive lymphocytes, which factor often contributes to autoimmunity?

____ trigger

Environmental trigger

A patient develops autoimmune disease after infection because lymphocyte receptors cross-react with host tissue. Which hypothesis explains this?

Molecular mimicry

Rheumatic heart disease after streptococcal infection is classically an example of which mechanism?

Molecular mimicry

A self-reactive T cell encounters a microbial mimic of self antigen. What additional condition is needed for activation?

A. Simultaneous local inflammation

B. Absent antigen presentation

C. Complete cytokine silence

D. Immediate eosinophil depletion

A. Simultaneous local inflammation

For molecular mimicry to activate self-reactive T cells, inflammation must occur in tissue that also expresses what?

A. IgE receptor

B. Self antigen

C. Fc fragment

D. Complement receptor

B. Self antigen

In insulin-dependent diabetes mellitus, which pancreatic cell type is initially targeted by autoimmune injury?

A. Alpha cells

B. Beta cells

C. Delta cells

D. Acinar cells

B. Beta cells

In insulin-dependent diabetes mellitus, beta cells are located in which organ?

A. Pancreas

B. Thyroid

C. Adrenal gland

D. Pituitary

A. Pancreas

Which immune cell initially attacks beta cells in insulin-dependent diabetes mellitus?

____ ____ cells

Killer T cells

Reduced CTLA-4 RNA increases diabetes susceptibility by impairing control of which cells?

_____-____ T cells

Self-reactive T cells

Which molecule normally helps restrain self-reactive T cells in diabetes susceptibility?

A. CTLA-4

B. CD40L

C. IL-17

D. IgM

A. CTLA-4

Plaque psoriasis most characteristically produces which skin finding?

____ and ____

Thickening and scaling

Plaque psoriasis is driven mainly by which immune cell type?

A. Th2 cells

B. B cells

C. CD8 cells

D. Neutrophils

C. CD8 cells

In plaque psoriasis, CD8 cells produce which cytokine that promotes keratinocyte proliferation?

IL-17

In plaque psoriasis, IL-17 causes proliferation of which cell type?

A. Keratinocytes

B. Fibroblasts

C. Chondrocytes

D. Oligodendrocytes

A. Keratinocytes

The proposed self-reaction in psoriasis involves class I MHC recognition of streptococcal antigens and what self-cell target?

A. Cartilage

B. Keratinocytes

C. Myelin

D. Beta cells

B. Keratinocytes

The proposed infectious trigger in plaque psoriasis involves which organism group?

A. Mycobacteria

B. Epstein-Barr virus

C. Streptococcal bacteria

D. Candida species

C. Streptococcal bacteria

Rheumatoid arthritis is primarily characterized by autoimmune inflammation of which structure?

A. Pancreatic islets

B. Central myelin

C. Hair follicles

D. Joints

D. Joints

In rheumatoid arthritis, autoimmune cells react against cartilage and a protein from which infection?

A. Tuberculosis

B. Epstein-Barr virus

C. Streptococci

D. Influenza

A. Tuberculosis

Which tissue antigen is targeted in rheumatoid arthritis?

A. Myelin

B. Cartilage

C. Keratin

D. Insulin

B. Cartilage

In rheumatoid arthritis, abundant IgM antibodies bind which region of IgG?

A. Fab region

B. Hinge region

C. Fc region

D. Variable region

C. Fc region

The IgM antibody that binds IgG Fc in rheumatoid arthritis forms which pathogenic structure?

A. Cytotoxic synapse

B. IgE tetramer

C. MHC complex

D. Immune complex

D. Immune complex

In rheumatoid arthritis, IgM-IgG immune complexes activate which inflammatory cell?

A. Macrophage

B. Mast cell

C. Basophil

D. Keratinocyte

A. Macrophage

Activated macrophages in rheumatoid arthritis produce which cytokine causing inflammation?

TNF

Multiple sclerosis involves immune-mediated destruction of which structure?

A. Cartilage

B. Keratin

C. Myelin

D. Beta cells

C. Myelin

Myelin is required primarily for which nervous-system function?

A. Cytokine production

B. Antibody secretion

C. Cartilage repair

D. Electrical signaling

D. Electrical signaling

Multiple sclerosis occurs almost exclusively in people previously infected with which virus?

Epstein-Barr virus

Epstein-Barr virus establishes chronic infection in which cell type?

____ cells

B cells

The classic facial rash of lupus involves which areas?

____ and ____

Forehead and cheeks

The “red wolf” appearance in lupus refers most directly to which manifestation?

A. Kidney damage

B. Hair loss

C. Arthritis

D. Facial red rash

D. Facial red rash

Systemic lupus erythematosus results from breakdown of tolerance in which lymphocyte groups?

A. B and T cells

B. NK and mast cells

C. CD8 and basophils

D. Neutrophils and monocytes

A. B and T cells

In lupus, loss of B- and T-cell tolerance results in production of which self-reactive antibody class?

IgG

One proposed lupus mechanism involves defective interaction between Fas and which partner molecule?

Fas ligand

Another proposed lupus mechanism involves mutation in which innate immune receptor family?

A. IgE receptors

B. TNF receptors

C. IL-2 receptors

D. Toll-like receptors

D. Toll-like receptors