mCuMVTT-RBM promotes IgA production and IgG
responses are dominated with IgG2a subclass
Previous studies have shown that the different IgG subclasses play an
essential role against viruses by complement fixation, enhancing
opsonization and immune effector function (28). Accordingly, it is of
interest to assess the IgG subclasses induced by the developed vaccine
candidate. We have tested the vaccine for its ability to induce IgG1,
IgG2a, IgG2b and IgG3. The results indicated that
mCuMVTT-RBM induces the production of all four
subclasses when binding is assessed on RBD protein as shown in Figure 3A
and B. Analysis of OD50 showed a predominance of IgG2a
and IgG1. These results were confirmed when assessing the binding to the
spike protein (Fig 3C and D).
Next, we tested the ability of mCuMVTT-RBM to induce
immunoglobulin class-switching to IgA using the two regimens D0/14 and
D0/28. Following, D0/28 regimen induced higher RBD-specific IgA titers
in comparison to D0/14 regimen (Fig. 3E). Measuring the
OD50 of IgA titers in both regimens confirmed the
difference in antibody titers (Fig. 3F).