Table 1.
IL-21R/γc-Fc | Clone 362.78 | Clone 362.597 | Clone 366.552 | Clone 366.328 | Clone 362.75 | Clone 366.345 | |
Epitope bin | #1 | #1 | #1 | #1/2 (overlap) | #2 | #2 | #3 (non-neutralizing) |
Isotype | n/a | IgG4, kappa | IgG1, kappa | IgG1, kappa | IgG4, kappa | IgG1, kappa | IgG (subtype n.d.) |
VH germline gene | n/a | VH3-33 | VH3-33 | VH4-59 | VH3-21 | VH4-39 | n.d. |
VL germline gene | n/a | VkIII A27 | VkIII A27 | VkI L5 | VκI L4 | VkIII L6 | n.d. |
Cross reacts with human IL-2, -4, -7, -9, or -15 | n.d. | No | No | No (western blot only) | No (western blot only) | No (western blot only) | n.d. |
Inhibits IL-21 binding to soluble homodimeric IL-21R | Yes | Yes | Yes | Yes | No | n.d. | No |
Inhibits IL-21 binding to soluble heterodimeric IL-21R/γc | Yes | Yes | Yes | Yes | No | n.d. | No |
Cross-reactivity to related γc cytokines was assessed by western blot analysis for all mAbs except 366.345. Clone 362.78 was further assessed for cross-reactivity to the related cytokines by surface plasmon resonance, and was also evaluated in bioassays for a subset of these cytokines (IL-2, -4 and -15; see Materials and Methods). Competition for IL-21 binding to soluble receptors was determined by surface plasmon resonance (Fig. 6); n/a, not applicable; n.d., not determined.