The progeny of a single virgin B cell predominates the human recall B cell response to the capsular polysaccharide of Haemophilus influenzae type b.
Restricted V region diversity is a key feature of Abs to many haptens and simple polysaccharides. Two possible mechanisms exist: 1) selection of many clonally unrelated B cells using very similar or identical VDJ and VJ rearrangements; and 2) selection of a heavily expanded progeny of few virgin B cells. How many virgin B cells eventually give rise to the total Ab response to a simple Ag is a fundamental immunologic question. In this report, we address this question in human adults by analyzing the rearranged VkappaJkappa genes of B cells responding to a single dose of the capsular polysaccharide of Haemophilus influenzae type b coupled to tetanus toxoid. We combined affinity purification of circulating vaccine-induced Ab-secreting cells with PCR amplification of cDNA followed by cloning and sequencing. Forty-eight and 42 kappa VJ gene transcripts were analyzed from two adults, respectively. Both individuals used extremely restricted repertoires with >90% of the cells using a single Vkappa gene rearranged to a single Jkappa gene. Despite the fact that the Ab responses engaged high numbers of Ab-secreting cells, analysis of the many shared, somatically acquired mutations showed that the majority of the cells originated from a common virgin B cell. Kinetic considerations implied that an extremely selected population of hypermutated memory B cells must have existed in these individuals before the first systemic immunization with the Ag. A possible role for the mucosal immune system in the priming and selection of these cells is proposed.
Department of Clinical Immunology, Rigshospitalet, National University Hospital, Copenhagen, Denmark.
T
T
Barington
L
L
Hougs
L
L
Juul
H O
HO
Madsen
L P
LP
Ryder
C
C
Heilmann
A
A
Svejgaard
D000328:Adult; D000942:Antigens, Bacterial / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D016667:Bacterial Capsules; D001483:Base Sequence; D002999:Clone Cells / Q000276:immunology*; D005260:Female; D015328:Gene Rearrangement, B-Lymphocyte, Light Chain; D005803:Genes, Immunoglobulin; D018073:Haemophilus Vaccines / Q000276:immunology*; D006193:Haemophilus influenzae / Q000276:immunology*; D006801:Humans; D007135:Immunoglobulin Variable Region / Q000235:genetics; D007145:Immunoglobulin kappa-Chains / Q000235:genetics; D007156:Immunologic Memory; D008297:Male; D008969:Molecular Sequence Data; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D012333:RNA, Messenger / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014611:Vaccination
D000942:Antigens, Bacterial; D018073:Haemophilus Vaccines; C044237:Haemophilus influenzae type b polysaccharide vaccine; D007135:Immunoglobulin Variable Region; D007145:Immunoglobulin kappa-Chains; D011135:Polysaccharides, Bacterial; D012333:RNA, Messenger