B15: mucosal immunity 3 Flashcards
What are the key immune defences in the urogenital tract (UGT)?
π©ββοΈ Female & π¨ββοΈ Male immune systems protect against STIs like HPV and HIV
What are the main parts of the respiratory tract (RT) immune system?
πΌ Upper RT (nose, sinuses) & π½ Lower RT (lungs, alveoli).
Name two common viruses of the RT.
π€§ Influenza (flu) and π¦ SARS-CoV-2 (COVID-19).
Which viruses have effective vaccines?
β Poliovirus π, HPV π§¬, COVID-19 π.
Which viruses have only moderately effective vaccines?
β οΈ Rotavirus π¦ , Flu (Influenza) π€§.
Which virus has no vaccine?
β HIV π¦ .
Match the virus to its genetic material:
SARS-CoV
Influenza
HPV
Poliovirus
HIV
Rotavirus
SARS-CoV π§¬: ssRNA
Influenza π¦ : ssRNA segmented
HPV π§¬: dsDNA
Poliovirus π¦ : ssRNA
HIV π¦ : mRNA
Rotavirus π¦ : dsRNA
What is the main type of immunoglobulin in the respiratory and urogenital tracts?
π‘οΈ IgG + IgA (99% in RT, 98% in UGT).
How does the UGT immune system adapt to balance defence and reproduction?
π‘οΈ Protects against STIs
π¦ Differentiates microbiota from pathogens
π£ Tolerates reproduction:
𧬠Sperm must fertilise the egg
π€° Fetus must not be rejected
π«Whatβs missing in the UGT immune system (unlike other mucosal sites)?
π«No MALT or M-cells (an adaptation to support reproduction).
π«What antibody can cause infertility in both men and women?
π«π§ͺ Anti-sperm antibodies β linked to 12% of male infertility cases.
Whatβs the difference between transudation and exudation?
π Transudation: Plasma filtrate flows across epithelium (carries IgG).
π Exudate: Fluid from tissue damage/inflammation.
What can cause tissue damage in the vaginal mucosa?
π¦ Microbes: HSV, bacteria, fungi
π₯ Irritants: Spermicides
π₯ Physical damage: Contact during intercourse, menstrual changes
How does the adaptive immune system fight infections in vaginal mucosa?
𧬠CD4+ T-cells π₯ block viral replication (IFNΞ³).
𧬠CD8+ T-cells π₯ kill infected cells.
π‘οΈ IgG from both local production & bloodstream block virus entry.
Why is there an effective vaccine for HPV but not HIV?
β
HPV: Slow mutations, strong systemic response (IgG).
β HIV: Fast mutations, weak antibody response, π οΈ HAART treatment controls the virus but doesnβt cure it.
How does the RT defend itself from infection?
π‘οΈ Mechanical barriers (nose hairs, mucus)
π§Ό Clearance mechanisms (cilia sweep away particles)
π¦ Microbiota
π οΈ Innate & adaptive immune cells
What are the 3 main sections of the respiratory tract?
πΌ Upper airways: NALT (nose, sinuses, pharynx)
π οΈ Central airways: BALT (trachea, bronchi β present mainly in children)
π½ Lower airways: Alveoli
Whatβs the difference between antigenic shift and drift?
π Antigenic shift: Major change due to gene reassortment (big mutation).
π Antigenic drift: Minor changes from small mutations over time (annual flu).
What is a cytokine storm?
πͺοΈ Overactive immune response β massive IL-6 cytokine release
π οΈ Causes tissue damage and inflammation, leading to severe outcomes (e.g., COVID-19 pneumonia).
What are the main routes of HIV transmission?
π Sexual transmission: Vaginal, anal, oral
π Blood-to-blood: Needles, transfusions (rare now)
π€± Mother-to-child: Birth, breastfeeding
π οΈ Mucosal exposure: Microtears in genital/rectal mucosa allow HIV entry
How does HIV invade the body after mucosal exposure?
1οΈβ£ Crosses mucosal epithelium β via microabrasions or direct transport by dendritic cells
2οΈβ£ Infects CD4+ T cells β uses CCR5 or CXCR4 coreceptors
3οΈβ£ Spreads systemically β travels to lymph nodes, blood, organs
What makes HPV an easier vaccine target than HIV?
β
HPV DNA is stable (HIV mutates rapidly)
β
HPV stays local (HIV spreads to immune cells)
β
HPV doesnβt integrate into DNA early (HIV integrates quickly)
β
HPV immune response is strong (HIV evades immunity)
Why do HIV vaccines fail so far?
π HIV mutates too fast
π‘οΈ Weak antibody response β HIV hides in cells
𧬠Glycan shield β Sugar coating blocks antibodies
π₯ Targets immune cells (CD4) β The cells meant to fight it get infected
How does HAART (Highly Active Antiretroviral Therapy) work against HIV?
π Reverse transcriptase inhibitors: Block viral RNA β DNA conversion
π Protease inhibitors: Stop new virus assembly
π Integrase inhibitors: Prevent virus from integrating into host DNA
π Entry inhibitors: Block virus binding to CD4+ cells
Whatβs a potential breakthrough strategy for HIV vaccines?
π οΈ Broadly neutralising antibodies (bNAbs) β target conserved parts of HIV
𧬠mRNA vaccines β like COVID-19, may boost immune response
π¬ T-cell vaccines β train CD8+ cytotoxic T-cells to kill infected cells faster
what is transudation in the urogenital tract
the flow of plasma filtrate in the epithelium, allowing immune elements like IgG to pass through - a potential defence mechanism
What is exudation?
fluid build-up caused by tissue leakage due to inflammation or cell damage.
What are some causes of tissue damage in the vaginal mucosa?
Microbial factors: Viruses (e.g., HSV), bacterial infections, Candida overgrowth
Physical factors: Sexual activity or tools
Menstrual cycle: Tissue changes throughout the cycle
Chemical irritants: Spermicides like nonoxynol-9 disrupt epithelial membranes
How do antibodies block viral entry in vaginal mucosa? π
Immunoglobulins (IgG, SIgA, mIgA) from both local and systemic sources block virus entry.
: What immune cells are found in the trachea and alveoli? π¦
Trachea: Ciliated epithelial cells (EC), goblet cells, dendritic cells, macrophages, CD4+, CD8+, B-cells (SIgA)
Alveoli: Type I & II epithelial cells, dendritic cells, macrophages, T-cells
What cytokine is heavily linked to cytokine storms and sepsis? π₯
IL-6 β high levels were observed in COVID-19 patients who didnβt recover.
