Abstract
Our laboratory develops protocols to prevent or reverse ongoing anti-hFIX IgG inhibitors in haemophilia B mice with a F9 gene deletion on BALB/c and C3H/HeJ backgrounds. C3H/HeJ F9-/Y mice develop high titre anti-hFIX IgG1 inhibitors and anaphylaxis, whereas most BALB/c F9-/Y mice have mild anti-hFIX IgG1 inhibitors and no anaphylaxis. Our aim was to determine if hFIX-specific B- and T-cell responses in BALB/c and C3H/HeJ F9-/Y mice trigger the difference in anti-hFIX immune responses. BALB/c and C3H/HeJ F9-/Y mice were challenged weekly with recombinant hFIX protein. Humoral immune responses were determined by IgG1 and IgG2a anti-hFIX ELISA, Bethesda assay for inhibitors and B-cell ELISpot on bone marrow and spleen cells. T-cell studies measured the TH1 (IFN-γ) and TH2 (IL-4) cytokine responses in splenocytes at the mRNA and protein level in response to hFIX protein. Antibody responses were also measured in C3H/HeJ/OuJ F9-/Y mice with restored toll-like receptor 4 (TLR4) function. BALB/c F9-/Y mice have a TH2 skewed response and a reduction in anti-hFIX secreting plasma cells in the bone marrow. Independent antigen challenge revealed both strains generated equivalent IgG1 antibody titres to an intravenously delivered antigen. C3H/HeJ F9-/Y mice have a mixed TH1 and TH2 response (mainly TH2). Importantly, TLR4 signalling has a modulatory role in the C3H background on the levels of anti-hFIX IgG1 and incidence of anaphylaxis. The background strain strongly impacts the immune response to hFIX, which can be significantly impacted by mutations in innate immune sensors.
Original language | English (US) |
---|---|
Pages (from-to) | 133-139 |
Number of pages | 7 |
Journal | Haemophilia |
Volume | 21 |
Issue number | 1 |
DOIs | |
State | Published - Jan 1 2015 |
Externally published | Yes |
Keywords
- Anaphylaxis
- BALBc
- C3H/HeJ
- Factor IX
- Haemophilia B murine model
- Immune response
ASJC Scopus subject areas
- Hematology
- Genetics(clinical)