Comparison between Hybridoma and Fab/phage Anti-RhD: Their V Gene Usage and Pairings

Our 11 anti-RhD's in conjunction with 37 previously published RhD antibodies, produced by hybridoma technology were analysed for germline gene usage and restriction in V(H) and V(L) pairings. The 17 V(H) germline genes used by the hybridoma anti-RhD IgG were derived from 4 VH families (VH1, VH2, VH3 and VH4). Eighteen kappa chains were restricted to only 5 germline genes from only 2 Vκ families (Vκ1 and κ3). However, the 13 lambda chains were not as restricted, using 10 V(λ) germline genes from 4 families (Vλ1, Vλ2, Vλ3 and Vλ8). Fifty six unique Fab/phage anti-RhD were also analysed. In all cases the Fab/phage V(H) germline genes were derived from the VH3 family (41/41). The 29 kappa chains were restricted to 4 germline genes primarily from Vκ1 (97%) germline genes from 5 families (Vλ1, Vλ2, Vλ3, Vλ4 and Vλ7). The V(H) germline genes of the Fab/phage were restricted to 4 of the 17 used by the hybridoma anti-RhD IgG (DP46, DP49, DP50 and DP77). Ninety percent of the Fab/phage were restricted to 1 of the 5 V(κ) germline genes used by the IgG (DPK9). However, the repertoire of the V(λ) germline genes used in these two systems is different, with analysis showing greater diversity in V(λ) gene usage with 8 unique germline genes used by 76% Fab/phage compared to 4 unique genes used by 46% hybriboma anti-RhD.