OT-II TCR transgenic mice fail to produce anti-ovalbumin antibodies upon vaccination

OT-II mice were evaluated as a transgenic strain-specific model to assess T-cell help for B-cell responses. OT-II CD4+ T-cells express transgenic OVA-specific αβ-TCRs. This high frequency of antigen-specific helper T-lymphocytes may augment induction of B-cell responses. Unexpectedly, OT-II mice did not produce OVA-specific antibodies after intranasal immunization. However, B-cells expressed normal antigen-presenting function in vitro for activation of OVA-specific T-cell responses. These OT-II T-cell responses produced a Th1-type cytokine profile with significantly reduced Th2 or Th17 responses. These data suggest that OT-II B-cells are not defective as APCs, however, downstream antibody responses are abrogated in this transgenic strain.

► OT-II mice did not produce OVA-specific IgG when immunized with CT-OVA.
► OT-II B-cells were competent in vitro as APCs to induce T-cell responses.
► OT-II transgenic T-cells expressed a highly polarized Th1 type cytokine profile.
► OT-II B-cells present OVA to T-cells but downstream IgG production is abrogated.