B14: mucosal immunity 2 Flashcards
🌟 What is the role of NALT?
🌟Involved in mucosal immune responses in the respiratory, digestive, and urogenital tracts.
🌟 What immune responses does NALT induce?
🌟Cytotoxic T cells (CTLs) and immunoglobulins (SIgA, IgG).
🌟What cells are crucial for antigen sampling in NALT?
🌟 M-cells.
🌟 What forms the Waldeyer’s ring?
🌟Tonsils and adenoids — forming a protective ring of lymphoid tissue.
🥦What makes GALT special?
🥦Largest MALT, packed with inductive & effector sites.
🥦Key cells in antigen sampling for GALT?
🥦M-cells and dendritic cells (DCs).
🥦 How does GALT maintain gut homeostasis?
🥦 Balances microbiota interactions to avoid inflammation.
🥦What immune tolerance does GALT mediate?
🥦Oral tolerance — prevents food allergies.
🛠️ How does the gut microbiota support the immune system?
🛠️Maturation, calibration, and homeostasis of mucosal immunity.
🛠️What happens when the microbiota is imbalanced (dysbiosis)?
🛠️Increased risk of inflammatory diseases like Crohn’s.
🛠️ Key products of the microbiota that regulate gut health?
🛠️ Short-chain fatty acids (SCFAs) — regulate inflammation and homeostasis.
💩How can antibiotics lead to C. difficile overgrowth?
💩Antibiotics wipe out commensal bacteria, letting C. diff take over.
💩Why is C. diff dangerous?
💩 It produces toxins, causing bloody diarrhoea, colitis, and pseudo-membrane formation.
💩What’s a last-resort treatment for C. diff?
💩Fecal transplant — restores healthy microbiota.
💪What are the three levels of gut immune barriers?
💪1️⃣ Mucus layer – keeps bacteria away from epithelial cells.
2️⃣ Rapid response – macrophages kill intruders fast.
3️⃣ Limited systemic exposure – avoids triggering full-body inflammation.
💪 What cells maintain homeostasis with the microbiota?
💪Treg cells (CD4+) — promote tolerance and SIgA production.
🧫 Difference between overt pathogens and opportunistic ones?
🧫🦠 Overt pathogens: Always cause disease (e.g., Salmonella).
🔄 Opportunists: Normally harmless but can become pathogenic in certain conditions (e.g., Candida albicans).
🧫 What are pathobionts?
🧫Members of normal microbiota that can turn pathogenic (e.g., Bacteroides fragilis).
💉 What’s the difference between mucosal and parenteral vaccines?
💉🧴 Mucosal vaccines – delivered via oral/nasal route, ideal for gut/respiratory pathogens (e.g., Rotavirus).
💪 Parenteral vaccines – injected intramuscularly or subcutaneously, great for systemic immunity (e.g., COVID-19).
💉 Which vaccine type induces SIgA?
👅 Mucosal vaccines — like oral polio vaccine (OPV).
What are the two types of polio vaccines?
A:
💉 IPV (Salk) – Inactivated, injection, no SIgA.
👅 OPV (Sabin) – Live, oral, induces SIgA.
What are the two rotavirus vaccines?
🦠 RotaRix – Human attenuated strain.
🐮 RotaTeq – Bovine-human reassortant.
What’s the main defence against rotavirus reinfection?
🛡️ SIgA — neutralises the virus and reduces replication.
