Genetic and temporal control of neonatal antibody expression.

Abstract

Two hybridoma cell lines were established with B cells derived from neonatal BALB/c spleen cells. The anti-dinitrophenyl (DNP) antibodies derived from these lines were characterized with respect to their isotype, affinity, and isoelectric point. Antiidiotypic reagents were prepared that permit an analysis of the representation of antibodies sharing idiotype with these two hybridomas in the developing and mature B cell pool of BALB/c mice (Igha) and other murine strains. One of the two antibodies, TF2-36, was found to be indistinguishable from 14% of anti-DNP monoclonal antibodies derived in fragment culture from spleen cells of 1-4-d-old BALB/c donors. B cells expressing this idiotype were found to represent approximately 2% of the anti-DNP-specific repertoire after the 1st wk of neonatal development and into adulthood. The second hybridoma antibody, TF2-76, was found to be expressed at very low levels during the first several days of neonatal development; however, B cells expressing this idiotype increased in frequency during the 2nd wk of neonatal development representing 7% of all DNP-responsive B cells 12-13 d after birth. The proportion of B cells expressing this idiotype also decreased to approximately 2% in adults. The relatively late appearance of B cells bearing this idiotype was confirmed by their susceptibility to tolerance induction after the 1st wk of neonatal development. Both the early neonatal clonotype, TF2-36, and the late neonatal antibody clonotype, TF2-76, were found to be expressed in a similar fashion in F1 mice constructed between Igha and Ighb parentals, but both were expressed at very low levels during the development of Ighb mice. Thus, the control of the magnitude of expression of these neonatal clonotypes appears to be associated with the Igh locus.

Comparison of the fetal and adult functional B cell repertoires by analysis of VH gene family expression.

“…Furthermore, an important observation was the major contribution of VH 36-60 expression to the DNP response . This was most pronounced in the fetal response and is consistent with our previous results indicating that predominant idiotypes 36 (52) and 460 (53)(54)(55), both associated with VH 36-60 (35,55,56), were produced in the DNP-specific fetal response (56) . In addition, the 460 idiotype is also a predominant idiotype found in the adult DNP response (53)(54)(55).…”

“…The results suggest that the anti-DNP response, in general, is very heterogeneous and that member(s) of all of the VH gene families tested can potentially code for anti-DNP antibodies in both the fetus and adult. The heterogeneous nature of the anti-DNP response and the ability of anti-DNP antibodies to be encoded by more than one VH gene family is consistent with other reports (35,(52)(53)(54)(55) .…”

Preferential expression of variable region heavy chain gene segments by predominant 2,4-dinitrophenyl-specific BALB/c neonatal antibody clonotypes.

“…During the first weeks after birth, this repertoire undergoes a reproducible and patterned expansion (3)(4)(5)(6)(7)(8)(9). Thus, in the first 3 days of neonatal life, all BALB/c neonates share three predominant 2,4-dinitrophenyl (DNP)-specific and three predominant 2,4,6-trinitrophenyl (TNP)-specific clonotypes (3).…”

“…Although the adult primary B-cell repertoire ofBALB/c mice exceeds 107 conotypes (1,2), the antibody repertoire at birth is limited to 104-105 different specificities (3,4). During the first weeks after birth, this repertoire undergoes a reproducible and patterned expansion (3)(4)(5)(6)(7)(8)(9).…”

“…In order to evaluate the contribution of such a developmentally ordered rearrangement of V segments to the repertoire of antigen-responsive B cells, we have examined the V genes utilized by three hybridomas derived by fusion of DNP-hemocyanin-stimulated neonatal spleen cells (4). The idiotypes expressed by the antibody products ofeach ofthese three hybridomas have been shown to be expressed independently on a high proportion of the anti-DNP monoclonal antibody products of BALB/c neonatal spleen cells (4).…”