Infection Science & Immunology – Tutorial 5 (Exam Preparation)

Aim and Learning Outcomes

• Tutorial purpose: prepare for Infection Science exam focused on essay–style questions.

• Learning Outcomes (LOs)

  • LO1 – Identify exam‐approach techniques.

  • LO2 – Practise answering questions.

  • LO3 – Identify, apply and practise revision strategies.

Exam Logistics & Technical Preparation

• Format: on–campus, closed-book, 2\,\text{hour} written essay exam, answers typed in Word and submitted through Moodle.

• Practical preparations

  • Know the exact room, date and start time.

  • Test university credentials a few days in advance; re-check morning of the exam.

  • Open Word via Moodle link; save locally and frequently (⌃ + S / File ➔ Save).

  • Allocate final minutes to verify the .docx saved correctly and was uploaded (green tick confirmation).

Reading the Paper Correctly

• Allocate initial time to read overall instructions.

• Clarify:

  • Number of questions to attempt.

  • Whether questions come from different sections; avoid missing sub-parts.

  • Do not exceed required number of answers—extra essays waste time & gain no credit.

Infection Science Lecture Map (Weeks 1 – 11)

• Week 1 (28 Jan)

  • Introduction to Immune System

• Week 2 (4 Feb)

  • Innate Immune System

• Week 3 (11 Feb – starred core)

  • Adaptive Immunity

• Week 4 (18 Feb)

  • Immune Response (IR) to Bacteria & Viruses — LS

  • IR to Parasites — NP

• Week 5 (25 Feb)

  • Diagnostics & Immunisation — NP

  • IR to Fungi — NP

• Week 6 (4 Mar) Biology of Infectious Agents

• Week 7 (11 Mar) Pathogenesis — MZ

• Week 8 (18 Mar) Antimicrobials & Resistance — JB

• Week 9 (25 Mar)

  • GI Infections — RS

  • Respiratory Infections — RS

• Week 10 (1 Apr)

  • Diagnostics — KW

  • Epidemiology & Infection Control — KH

• Week 11 (8 Apr)

  • Microbiology & Immunology Revision sessions

(Identical timetable repeated on p. 6 to reinforce.)

Detailed Weekly Learning Objectives

Week 1 – Foundations

• Pathogens & Immune Organs

  • Recognise pathogen features driving infection & immunity.

  • Describe primary/secondary lymphoid organs & their functions.

• Key Immune Molecules

  • Contrast innate vs adaptive chemokines, receptors, soluble mediators.

• Cells of the Immune System

  • Categorise leukocytes by lineage (myeloid / lymphoid), structure, function.

  • Detail receptors (PRRs, BCR, TCR, Fc, etc.) and effector roles per cell type.

Week 2 – Innate Immunity in Depth

• Protective Barriers & Molecules

  • Skin, mucosa, antimicrobial peptides, complement, cytokines.

• Phagocytosis Mechanisms

  • Attachment ➔ ingestion ➔ phagolysosome fusion

  • Oxidative burst (NADPH oxidase, O_2^-) & non-oxidative enzymes.

• Complement

  • Components, three activation pathways, opsonisation, MAC.

• Inflammation

  • Cardinal signs; cell/molecular mediators (TNF-α, IL-1β, prostaglandins); resolution vs chronicity.

Week 3 – Adaptive Immunity

• B Cells & Antibody Structure/Function

  • Heavy/light chain architecture, Fab/Fc, isotope roles (IgM, IgG, etc.).

  • B-cell development, clonal selection.

• Generating Diversity

  • Genetic loci organisation.

  • V\text{–}(D)\text{–}J recombination + junctional diversity.

  • Somatic hypermutation & class switch recombination.

• T Cells & Cell-Mediated Immunity

  • Thymic maturation, positive/negative selection.

  • TCR rearrangement, co-receptors CD4 / CD8.

  • Activation cascade & effector subsets: Th1, Th2, Th17, Treg, CTL.

Week 4 – Host–Pathogen Interactions I

• Bacterial Immunology

  • Extracellular vs intracellular tactics; exotoxins vs endotoxin; immune evasion (capsules, antigenic variation).

• Viral Immunology

  • Capsid/enveloped structure influences MHC-I vs Ab responses; viral evasion (latency, IFN blockage).

• Parasitic Immunology

  • Life-cycle complexity dictates IgE & eosinophil bias; immune modulation by helminths.

Week 5 – Host–Pathogen Interactions II & Clinical Tools

• Fungal Immunology

  • Cell-wall β-glucans recognised by Dectin-1; Th17 importance.

• Immunisation

  • Principles: memory, herd immunity.

  • Vaccine generations (live-attenuated, subunit, mRNA) with pros/cons.

• Diagnostics

  • Serology (ELISA), PCR, microscopy—indications, sensitivity/specificity.

Weeks 6 – 10 (High-level only)

• W6 – Biology of Infectious Agents

• W7 – Pathogenesis concepts (adherence, invasion, toxin production, immune subversion).

• W8 – Antimicrobials & Resistance (mechanisms, MIC testing, stewardship).

• W9 – GI & Respiratory Infections (common pathogens, immune niches).

• W10 – Advanced Diagnostics & Infection Control (Epi curves, R₀, standard precautions).

• W11 – Full revision (micro & immunology) ➔ consolidation.

Revision Preparation Activities

Activity 1 – Personal Audit

• List every lecture/topic; code confidence green / amber / red.

• Adjust timetable: allocate more sessions to red sections.

• Select one weak topic; spend 10\,\text{min} applying a technique below.

Core Revision Techniques

1. Expand Topics (Column Method)

   • Left = heading, Right = free recall bullet notes, then refine with textbooks.

   • Example (Cells of Immune System) includes lineage tree from HSC ➔ myeloid & lymphoid branches; functions of B cells, T cells, NK, granulocytes, APC transition, etc.

2. Mind-Mapping / Make Connections

   • Central bubble (e.g. Dendritic Cells); spokes: PRRs, antigen uptake (endocytosis, phagocytosis, macropinocytosis), migration ⇄ tissues ⇄ LNs, cytokines (TNF-α, IL-12), activation of Th/Tc/NK.

3. Link-Template Table

   • Choose key terms (Macrophage, Innate, Cytokine, PAMP, Opsonisation, TLR 1–9). Write relationship sentences.

Activity 2 – Compose Your Own Question

• Use lecture LOs as blueprint; submit via Microsoft Forms (URL provided).

• Objective: internalise assessment focus & anticipate exam angles.

Activity 3 – Planning Answers

• Select question (self-made or peer’s).

• Produce skeleton outline:

  • Intro sentence framing scope.

  • Thematic subsections (pathogen structure, immune recognition, evasion, clinical outcome, etc.).

  • Allocate time blocks; ensure balance across mark weighting.

Activity 4 – Practice, Review, Refine

• Past-paper example (Schistosoma case) supplied for timed attempt.

• After writing, self-audit with checklist (coverage, flow, duplication, insight).

Exam Answering Strategy

1 – Decode the Question

• Identify topic (e.g. schistosomiasis), command verb (explain, discuss, compare), and scope limits (life-cycle only, or innate & adaptive both).

• Draft mini-plan before writing.

2 – Communicate Effectively

• Scientific register: third person, past tense where historical (“was discovered…”).

• Structured paragraphs with topic sentence ➔ evidence ➔ significance.

• Use figures/tables when they save word count & clarify (label clearly, reference in text).

3 – Compose & Revise

• Plan – Compose – Revise triad.

• During revision phase, check for:

  • Logical sequencing.

  • Removal of redundancies.

  • Correct nomenclature (e.g. Escherichia coli → E. coli after first mention).

Writing Style & Conventions

• Species names italicised, genus capitalised, species lowercase.

• Abbreviations introduced once, e.g. Methicillin-Resistant Staphylococcus aureus (MRSA).

• Precise statements: avoid “some cells” → specify “CD4⁺ Th1 lymphocytes”.

Worked Example – Schistosoma mansoni Essay

Part A (15 marks)

• Mode of transmission: contact with freshwater cercariae released from intermediate snail host; skin penetration.

• Life-cycle chronological points (ensure each numbered & labelled IN/DIAG stage):

  1. Eggs in human urine/faeces reach water.

  2. Eggs hatch ➔ miracidia.

  3. Miracidia penetrate aquatic snails.

  4. Successive sporocyst generations occur in snail.

  5. Cercariae emerge, free-swimming.

  6. Human skin penetration; tail loss ➔ schistosomulae.

  7. Vascular migration ➔ portal circulation.

  8. Adult worm pairing in mesenteric or vesical plexus.

  9. Eggs laid; some excreted (diagnostic stage), others cause granulomatous pathology.

Part B (30 marks)

• Innate defence

  • Dermal barrier; complement-mediated lysis (limited by larval glycocalyx).

  • Eosinophils + mast cells; pattern recognition via TLRs recognising parasite glycans.

• Adaptive cellular

  • Th2 skewing; IL-4, IL-5 drive eosinophilia.

  • CD4⁺ T cells form granulomas around eggs.

• Humoral

  • IgE binding to surface antigens; FcεR-dependent eosinophil degranulation (antibody-dependent cell-mediated cytotoxicity, ADCC).

  • IgG subclasses contributing to neutralisation; possible IgM in early infection.

• Immunomodulation by parasite

  • Tegument shedding; secretion of proteases to cleave Ig; induction of IL-10 & Treg responses.

(Use outline above to test self-answer; cross-check vs 30-mark weighting: breadth + depth + mechanisms.)

Additional Practice Questions (via Moodle)

1. Challenges of old vs new-generation vaccines.

2. TCR rearrangement & diversity contrasted with BCR mechanisms.

• PDF with full paper available post-lectures; Q&A drop-in advertised on Teams (see timetable).

External Study-Skill Resources

• MMU Study Skills video series covering:

  • Academic style, tense consistency, critical writing, structuring with headings.

• Access: https://www.mmu.ac.uk/student-life/course/study-skills/online/

Key Take-Home Message: Use the lecture LOs as your revision spine, practise decoding verbs, plan structured scientific essays, and actively connect innate/adaptive, pathogen/host, and theory/clinical examples to maximise marks.