Klaus Karjalainen

Inherited Immunoglobulin Idiotypes of the Mouse

A-CHO, group A streptococcal polysaccharide; cap; epsilon-aminocaproyl; Cg gene and Cj^ gene, the structural germ-line gene for the H chain or the L chain constant polypeptides; HPI, Haptenated Phage Inactivation method for detecting anti-hapten antibodies; IEF, isoelectric fociising; NBrP, (4-hydroxy-5-bromo-3-nitrophenyl) acetyl; NIP, (4-hydroxy-5-iodo-3-nitrophenyl) acetyl; NNP, (4-hydroxy-3, 5-dinitrophenyl) acetyl; NP, (4-hydroxy-3-nitrophenyl) acetyl; PC, phosphorylcholine; TMV, tobacco mosaic virus; V region, in this text, the part of an immunoglobulin molecule consisting of a Vg and a V^ domains or polypeptides (= Fy piece); Vg gene and V^ gene, structural germ line gene for the H chain or the L chain variable polypeptides.

Failure to demonstrate public idiotypes on cytolytic cells with specificity for NP-coupled syngeneic cells.

We have investigated whether cytolytic cells specific for hapten‐coupled syngeneic cells have the same public idiotype as serum antibodies against the same hapten, NP‐aminocaproyl (NP‐cap). Anti‐NP‐cap antibodies of C57BL mice possess a public idiotype that can be detected by antisera against the whole V region of the antibody molecule or against the VH domain. Neither reagent had an effect on the cytolytic response either when they were used to sensitize the effector cells for complement killing or when used at high concentrations in the culture medium during the secondary stimulation in vitro.

Linkage and recombination of VH gene markers, Np and Nb, in recombinant inbred strains of mice.

Mice of 24 recombinant inbred (RI) strains of the BXD series were typed for Igh markers, Np and Nb. In 22 strains these markers were concordant with the allotype (10 DBA/2-like and 12 C57BL/6-like). Strains BXD-20 and BXD-27 had a recombinant haplotype; their allotype was DBA/2-like but the Np and Nb characteristics were C57B/6-like.

Preferential production of IgA antibodies by spleen fragments immunized and maintained in vitro.

Primary immune responses were induced with a hapten conjugate of Ficoll (NIP38‐Ficoll) in cultures of mouse spleen fragments. The production of anti‐NIP antibodies and mouse immunoglobulins IgA and IgG was monitored by solid‐phase radioimmunoassays. Cultures produced IgA and IgG without any stimulation, IgA at a rate of c. 60 ng/mg of wet tissue per day throughout the 10‐day culture period. Background production of IgG gradually declined from almost 1000 ng/mg day at the beginning to 100 ng/mg day at the end. Immunization modestly reduced the decline of the IgG production. It increased the production of IgA fourfold between days 6 and 8. It induced an antibody production that had its peak between days 6 and 8. Up to 50 ng of anti‐NIP antibody was produced during this period per mg of wet tissue per day. Of this antibody 75–90% was IgA. When the same antigen was injected into mice, more than 75% of anti‐NIP antibodies detected in their sera on day 8 were IgG. One cause of the high ratio of IgG/IgA antibodies in vitro is the efficient elimination of oligomeric IgA by the liver. Another possible cause is that the production of IgA is less sensitive than the production of IgG to the adverse conditions of the culture.