Immunology summary flashcards

What are the three main lines of defence in the body?

1. External barriers 2. Innate immune system 3. Adaptive immune system

Name the four cardinal symptoms of inflammation.

Pain, heat, redness, and swelling

What are the main differences between acute, hypersensitivity, and chronic inflammation?

Acute: rapid & short. Hypersensitivity: adaptive immune reaction. Chronic: long-lasting, often autoimmune or allergic.

What are selectins and integrins?

Cell adhesion molecules (CAMs) that regulate leukocyte migration during inflammation

What are the steps of phagocytosis?

Recognition → Internalization → Phagolysosome fusion → Killing of pathogen

Name two types of phagocytes and their main characteristics.

Neutrophils: short-lived, early. Macrophages: long-lived, antigen presenting.

What are PAMPs and PRRs?

PAMPs: Pathogen-Associated Molecular Patterns. PRRs: Pattern Recognition Receptors that detect PAMPs.

How do NK cells identify and kill infected cells?

They detect missing/altered MHC class I and trigger apoptosis via granules.

What is an acute-phase response?

Liver changes protein production, increasing acute-phase proteins during inflammation.

Name three key acute-phase proteins and their functions.

CRP: complement activation; MBL: binds mannose; Fibrinogen: coagulation.

What are the three complement activation pathways?

Classical (antibody), Lectin (MBL), Alternative (pathogen surface).

What is MAC and what does it do?

Membrane Attack Complex forms pores in target membranes, causing lysis.

What are the five main immunoglobulin classes and their functions?

IgG: common, complement. IgM: early. IgA: mucosal. IgE: allergy. IgD: immature B-cells.

What is somatic hypermutation?

Mutation of antibody genes to increase affinity for antigen.

What enzyme is responsible for isotype switching and hypermutation?

AID (Activation-Induced Cytidine Deaminase)

What is the difference between monoclonal and polyclonal antibodies?

Monoclonal: one epitope. Polyclonal: multiple epitopes.

What does ELISA measure?

Presence and amount of specific antigens or antibodies.

Define sensitivity and specificity.

Sensitivity: detect true positives. Specificity: avoid false positives.

What are the main types of T-cells and their co-receptors?

Th-cells (CD4+): help B/macrophages. Tc-cells (CD8+): kill infected cells.

What are the three signals required for T-cell activation?

1. Antigen recognition 2. Co-stimulation 3. Cytokine signalling

What is the difference between MHC class I and II?

MHC I: all nucleated cells, CD8+. MHC II: APCs, CD4+.

What are cytokines?

Small signalling proteins that regulate immune responses.

Name two pro-inflammatory and two anti-inflammatory cytokines.

Pro: IL-1β, TNF. Anti: IL-10, TGF-β.

What are the three types of cytokine actions?

Autocrine, Paracrine, Endocrine.

What antibodies are involved in allergies?

IgE

What are the early and late phases of an allergic reaction?

Early: mast cell degranulation. Late: eosinophil activation, tissue damage.

How does Th1/Th2 regulation affect allergies?

Strong Th2 → allergy risk ↑; Th1 suppresses via IFNγ.

What is flow cytometry used for?

Rapid measurement and analysis of cells using fluorescence.

What is phenotyping?

Identifying cells based on physical/surface characteristics.

What is MALT and its function?

Mucosa-Associated Lymphoid Tissue; samples antigens at mucosal surfaces.

What antibody dominates mucosal immunity?

IgA (secretory form).

What are M-cells and where are they found?

Specialized cells in Peyer’s patches transporting antigens to immune cells.

What makes an ideal vaccine?

Safe, protective, long-lasting immunity.

What is an adjuvant?

Substance enhancing immune response (e.g., LPS, cytokines).

What are antiviral drug targets?

Viral DNA polymerase and protease enzymes.

What differentiates autoimmunity from autoinflammation?

Autoimmunity: adaptive (B/T). Autoinflammation: innate (macrophages).

Name one organ-specific and one systemic autoimmune disease.

Organ-specific: Type 1 diabetes. Systemic: Rheumatoid arthritis.

What are the five criteria for diagnosing autoimmune disease?

Autoantigen, Autoantibody, Passive transfer, Experimental model, Treatment effect.