Immunoglobulin heavy chain rearrangements from human kappa and lambda B cells

IntroductionThe advantage of two immunoglobulin light chains, kappa and lambda, in vertebrates is unknown. We compare the associated heavy chain variable domains to explore possible differences dependent on light chain usage.Materials and MethodsB cells from 35 healthy human adults were isolated dependent on light chain usage. VDJ rearrangements of the heavy chains were examined.ResultsA total of 60,750 unique, functionally rearranged sequences were identified of which 31,763 (52%) originated from B cells expressing the kappa light chain. The VDJ repertoires and H-CDR3 sequences displayed substantial similarity. Minor differences included differential utilization of specific VH- and JH genes. Notably, JH6 was more prevalent in kappa-expressing B cells (37.2% compared to 32.2% in lambda light chain-expressing cells, p<0.001). Furthermore, the H-CDR3 regions were generally longer in kappa-expressing B cells (average difference 0.9 bp, p<0.001). Additionally, arginine was more frequently found in the H-CDR3 regions of kappa light chain-expressing B cells (6.1% vs 5.7%, p<0.001) and the proportion of mutated sequences was higher in lambda light chain-expressing B cells (22.0% vs. 19.6%, p<0.001).21112016Primerup: TGAGGTGAAGAAGCCTGGG IGHV1Primerup: CTCTGGGTTCTCACTCAGC IGHV2Primerup: GAGGTGCAGCTGGTGGAG IGHV3_2Primerup: GTCCCTGAGACTCTCCTGT IGHV3Primerup: ACCCTGTCCCTCACCTGC IGHV4Primerup: TGGAGCAGAGGTGAAAAAGC IGHV5Primerup: TTGCTGTTTCCTTTTGTCTCC IGHV6Primerup: ATGAATTGGGTGCGACAGG IGHV7_2Primerdown: GGTCACCGTCTCCTCAGG IGHJ1456MID barcode: AACCATCCGC MID27kappaMID barcode: ATCCGGAATC MID28lambda16122016Primerup: TGAGGTGAAGAAGCCTGGG IGHV1Primerup: CTCTGGGTTCTCACTCAGC IGHV2Primerup: GAGGTGCAGCTGGTGGAG IGHV3_2Primerup: GTCCCTGAGACTCTCCTGT IGHV3Primerup: ACCCTGTCCCTCACCTGC IGHV4Primerup: TGGAGCAGAGGTGAAAAAGC IGHV5Primerup: TTGCTGTTTCCTTTTGTCTCC IGHV6Primerup: ATGAATTGGGTGCGACAGG IGHV7_2Primerdown: GGTCACCGTCTCCTCAGG IGHJ1456MID barcode: CTAAGGTAAC MID1_kappa171116MID barcode: TAAGGAGAAC MID2_lambda171116MID barcode: AAGAGGATTC MID3_kappa231116MID barcode: TACCAAGATC MID4_lambda231116MID barcode: CAGAAGGAAC MID5_kappa301116MID barcode: CTGCAAGTTC MID6_lambda301116MID barcode: TTCGTGATTC MID7_kappa071216_1MID barcode: TTCCGATAAC MID8_lambda071216_1MID barcode: TGAGCGGAAC MID9_kappa071216_2MID barcode: CTGACCGAAC MID10_lambda071216_2MID barcode: TCCTCGAATC MID11_kappa081216MID barcode: TAGGTGGTTC MID12_lambda081216