KUBY IMMUNOLOGY COVID 19 DIGITAL
UPDATE 2026 ANTIGEN RECOGNITION
AND LYMPHOCYTE ACTIVATION REVIEW
PACKAGE
◉ What is the major role of CD8 T cells during influenza infection?
Answer: To kill infected cells using perforin/granzyme, Fas-FasL
interactions, or TNF-α.
◉ How do helper T cells support antiviral immunity during
influenza infection?
Answer: They secrete cytokines that activate CD8 T cells, NK cells,
and B cells.
◉ Approximately when does the peak T-cell response occur after
influenza infection?
Answer: About 8-10 days after inoculation
◉ What cytokine environment promotes class switching to IgA
during influenza infection?
Answer: TGF-β-rich mucosal environments
,◉ Why is IgA important in influenza immunity?
Answer: It neutralizes virus at respiratory mucosal surfaces.
◉ How does secretory IgA enter the respiratory lumen?
Answer: Through the J chain/secretory component transport
system.
◉ What is the role of serum IgG during influenza infection?
Answer: It opsonizes and neutralizes virus in alveoli.
◉ Approximately when are measurable antibody responses detected
after influenza infection?
Answer: 1-2 weeks after inoculation
◉ When does the peak antibody response occur after influenza
infection?
Answer: Around 4 weeks after inoculation
◉ What inflammatory cytokines contribute to systemic symptoms
during influenza infection?
Answer: IL-1, IL-6, and TNF-α
◉ What is a cytokine storm?
, Answer: An excessive inflammatory response that causes tissue
damage and organ dysfunction.
◉ Which severe influenza strain is especially associated with
cytokine storm?
Answer: H5N1 influenza
◉ Why does influenza increase risk for secondary bacterial
pneumonia?
Answer: It damages respiratory epithelium and impairs mucociliary
clearance.
◉ Which bacteria commonly cause secondary bacterial pneumonia
after influenza?
Answer: Staphylococcus aureus, Streptococcus pneumoniae, and
Haemophilus influenzae
◉ How can influenza evade innate immune responses?
Answer: By downregulating TLR expression and suppressing PMN
chemotaxis and oxidative burst.
◉ How can influenza evade adaptive immune responses?
Answer: Through antigenic drift, antigenic shift, and downregulation
of MHC expression.
UPDATE 2026 ANTIGEN RECOGNITION
AND LYMPHOCYTE ACTIVATION REVIEW
PACKAGE
◉ What is the major role of CD8 T cells during influenza infection?
Answer: To kill infected cells using perforin/granzyme, Fas-FasL
interactions, or TNF-α.
◉ How do helper T cells support antiviral immunity during
influenza infection?
Answer: They secrete cytokines that activate CD8 T cells, NK cells,
and B cells.
◉ Approximately when does the peak T-cell response occur after
influenza infection?
Answer: About 8-10 days after inoculation
◉ What cytokine environment promotes class switching to IgA
during influenza infection?
Answer: TGF-β-rich mucosal environments
,◉ Why is IgA important in influenza immunity?
Answer: It neutralizes virus at respiratory mucosal surfaces.
◉ How does secretory IgA enter the respiratory lumen?
Answer: Through the J chain/secretory component transport
system.
◉ What is the role of serum IgG during influenza infection?
Answer: It opsonizes and neutralizes virus in alveoli.
◉ Approximately when are measurable antibody responses detected
after influenza infection?
Answer: 1-2 weeks after inoculation
◉ When does the peak antibody response occur after influenza
infection?
Answer: Around 4 weeks after inoculation
◉ What inflammatory cytokines contribute to systemic symptoms
during influenza infection?
Answer: IL-1, IL-6, and TNF-α
◉ What is a cytokine storm?
, Answer: An excessive inflammatory response that causes tissue
damage and organ dysfunction.
◉ Which severe influenza strain is especially associated with
cytokine storm?
Answer: H5N1 influenza
◉ Why does influenza increase risk for secondary bacterial
pneumonia?
Answer: It damages respiratory epithelium and impairs mucociliary
clearance.
◉ Which bacteria commonly cause secondary bacterial pneumonia
after influenza?
Answer: Staphylococcus aureus, Streptococcus pneumoniae, and
Haemophilus influenzae
◉ How can influenza evade innate immune responses?
Answer: By downregulating TLR expression and suppressing PMN
chemotaxis and oxidative burst.
◉ How can influenza evade adaptive immune responses?
Answer: Through antigenic drift, antigenic shift, and downregulation
of MHC expression.
