Genetic control of the immune response to myoglobin. IV. Mouse antibodies in outbred and congenic strains against sperm-whale myoglobin recognize the same antigenic sites that are recognized by antibodies raised in other species

The determination of the entire antigenic structure of sperm-whale myoglobin (Mb) was initially performed with antisera raised in rabbits and goats. Subsequently, we demonstrated that the synthetic antigenic sites were effective in stimulating $\text{in vitro}$ mouse T-cell proliferation and that this proliferative response was under genetic control, with each antigenic site being controlled by a unique Ir gene. To determine unambiguously whether T-cells recognize the same molecular features as do B-cells, it was necessary to establish whether mouse antibodies are directed against these same sites. In the present work, using immunoadsorbent titration studies, these synthetic antigenic sites were shown to bind mouse ¹²⁵I-labelled antibodies against Mb. With each of three outbred mice and four congenic strains, the total amounts of antibodies bound by the five sites accounted quantitatively for the entire antibody response against Mb. Moreover, with the four congenic strains, only the sites that were active in T-cell proliferation bound significant amounts of antibodies. It was concluded that (at least for Mb) the molecular features recognized by B-cells are also recognized by T-cells. These studies also confirm that the antigeniclty of the sites Is Independent of the immunized species and is inherent in their three-dimensional locations.     

Time-dependent study of the antibody response to sperm-whale myoglobin: recognition of the antigenic sites is unaltered over an extended period of immunization

We have recently shown that the antigenic structure of sperm-whale myoglobin is not dependent on the host species in which the antisera are raised. The purpose of the present work was to determine whether or not the molecular immune recognition of a protein by antibody is subject to a time-dependency. We have investigated the recognition of the antigenic sites by serial antisera obtained in two rabbits at different times after the initial immunization, from the earliest bleeding with detectable antibodies (9 days) up to a year. The specificity of these antisera was determined by their cross-reactions with 13 myoglobins from different species. The reactivity was measured by quantitative immunoadsorbent titration studies from the amount of radioiodinated antibodies that could be bound maximally (i.e. plateau binding values) by immunoadsorbents of each myoglobin. From these studies and our recent structural analysis, which enabled us to identify for each of these myoglobins the regions retaining reactivity with antibodies to sperm-whale myoglobin, we have concluded that following maturation of the immune response the antigenic recognition of a protein (i.e. the regions that are recognized as antigenic) is not dependent upon the time antisera are obtained after the first immunization. In the early periods of the response, fluctuations are observed in the relative immunodominance of the sites. This further confirms our earlier conclusions that the antigenic sites on a protein are structurally inherent in the protein.     

Preparation of T-lymphocyte lines and clones with specificities to preselected protein sites by in vitro passage with free synthetic peptides: Demonstration with myoglobin sites

Recently, this laboratory has demonstrated that antibodies to preselected regions of a protein can be obtained by immunization with free small synthetic peptides (6–7 residues) without conjugation to a carrier. In the present work, we report the use of free synthetic peptides representing myoglobin (Mb) antigenic sites to prepare T-cell lines and clones of preselected specificities. Lymph node cells from mice primed $\text{in vivo}$ with sperm-whale Mb were periodically passaged $\text{in vitro}$ with synthetic peptide. After several passages, the peptide-driven long term T-cell cultures responded to the intact protein and exclusively to the peptide that was used to drive the cells. From these cultures, T-cell clones were prepared that responded only to the driving peptide and to the whole protein. The ability to prepare T-cell lines and T-cell clones with preselected submolecular specificities to a protein by driving cultures with desired synthetic peptides affords an important and simple tool for basic immunological investigations and for clinical applications.     

Genetic control of the immune response to myoglobin. IX. Overcoming genetic control of antibody response to antigenic sites by increasing the dose of antigen used in immunization

Previously, it was reported that the immune response to myoglobin (Mg) was under genetic control, with the response to each site being under separate Ir-gene control. Here we have investigated the effect of antigen dose on the control of the antibody response to the five antigenic sites of sperm-whale Mb to determine whether or not the overcoming of genetic control by antigen dose has a uniform effect on all five antigenic sites. The antibody response to sperm whale myoglobin (Mb) and its five antigenic was measured in the following inbred strains of mice, C57BL/6J, AKR and SWR/J. These strains of mice are low responders to Mb following immunization with 50 micrograms, responding only to site 4. After immunization with 200 micrograms Mb: C57BL/6J mice are high responders to Mb and respond to antigenic sites 1, 3, 4 and 5; AKR mice are high responders to Mb and respond to antigenic sites 1 and 4; SWR/J mice are high responders to Mb and respond to all five antigenic sites. It was concluded that the genetic control of the immune response to Mb and its synthetic antigenic sites is dependent on antigen dose. Also, these studies have enabled us for the first time to separate the response to site 1 from the response to site 2 and thus have conclusively established that sites 1 and 2 are controlled by separate Ir-genes.     

Production of monoclonal antibodies with preselected submolecular binding specificities to protein antigenic sites: antibodies to sperm whale myoglobin sites

The five synthetic antigenic sites of sperm whale myoglobin were used in their free form (i.e. not coupled to any carrier) to immunize separate groups of BALB/cByJ mice. The synthetic peptides corresponded to: site 1, residues 15-22; site 2, residues 56-62; site 3, residues 94-99; site 4, residues 113-119; site 5, residues 145-151. Serum samples obtained from each group of mice contained antibodies that bound specifically to myoglobin and exclusively to the immunizing antigenic site. Monoclonal antibodies to each of the five antigenic sites were subsequently obtained by hybridizing Fa/O mouse myeloma cells with spleen cells derived from each group of mice. These monoclonal antibodies were either IgM(kappa) or IgGl(kappa). They expressed the same isotypes as the antigen specific serum antibodies produced by the mice whose spleen cells were used for hybridization. Solid phase radioimmunoassay studies also indicated that each monoclonal antibody, like the immune serum of the parent animals, bound specifically to myoglobin and exclusively to the synthetic peptide used as an immunogen. These results suggested that the hybridoma antibodies expressed submolecular binding specificities that were the result of peptide immunization rather than hybrid selection. This strongly supports our previous findings that it is possible to produce monoclonal antibodies with preselected submolecular binding specificities to continuous protein determinants by the techniques of somatic cell hybridization when the corresponding free synthetic determinants are used as immunogens.     

Genetic control of the immune response to hen's egg-white lysozyme in mice. I. Antibody and T-lymphocyte proliferative responses to the native protein.

We have initiated studies to determine whether the antibody and T-lymphocyte proliferative responses to lysozyme and its antigenic sites is genetically controlled in mice. Mice of the H-2f, H-2k and H-2p were high responders, while haplotypes H-2b, H-2d, H-2r and H-2s were low responders. Studies with recombinants indicated that the immune response is controlled by two H-2I region loci, one being in the I-A subregion and the other may be in the I-C subregions.     

Genetic control of the immune response to myoglobin. XVI. Control of antibodies with preselected specificities following immunization with free synthetic peptides representing the antigenic sites or surface non-immunogenic locations in the protein

Previous studies in this laboratory have resulted in the determination of the antigenic structure of myoglobin. The present work was carried out to investigate the genetic control of the murine antibody response to myoglobin following immunization with free (i.e., not coupled to a carrier) synthetic antigenic sites or other peptides corresponding to surface regions of myoglobin that are not immunogenic when the native molecule is the immunizing antigen. Synthetic peptides corresponding to antigenic site 1 (peptide 15-22), site 2 (peptide 56-62), site 3 (peptide 94-100), site 4 (peptide 113-120), site 5 (peptide 145-151) and two surface regions, peptide 1-6 and peptide 121-127, were injected in complete Freund's adjuvant in different strains of mice. Serum antibodies specific for myoglobin were subsequently obtained and were measured by means of a radioimmune plate binding assay in which Mb was used as the solid phase antigen. It was found that the genetic control of the antibody response to myoglobin following immunization with the free synthetic peptides was different from the genetic control obtained following immunization with native myoglobin. The significance of this finding is discussed.     

Genetic control of the immune response to ferritin in F1 hybrid mice.

The immune response to the antigen horse spleen ferritin, has been investigated in ten inbred parental strains and seven different F1 hybrid strains of mice, using an antigen excess technique. The degree of dominance in an F1 hybrid system can be estimated by using the Fisher dominance index. The responses in F1 hybrid animals, obtained from crosses of high and low responder parents, varied from dominant to recessive but the overall mean dominance index for the ferritin immunogenetic system was found to be -0.0467 +/- 0.0083 (mean +/- s.e.), a value close to zero, which suggests a codominant mode of inheritance of IR-genes to ferritin and this is consistent with most published data in other F1 IR-gene systems.     

Genetic analysis of isolation-induced aggression. II. Postnatal environmental influences in AB mice

Recently, we reported on two closely related inbred mouse strains, ABG and AB//Halle, that display extreme differences in isolation-induced intermale aggression. In the present article we investigated the influence of both maternal and social postnatal environmental influences. No effects were found of the postnatal maternal environment. Likewise, whether animals after weaning were housed together in same-strain or mixed-strain groups did not influence their subsequent aggressive behavior. We conclude that the aggressive behavior of ABG and AB//Halle is rather robust with regard to postnatal environmental modification and that the difference between the two strains is most likely due to only few genetic factors.     

Features of the immune response to DNA in mice. I. Genetic control.

The genetic control of the immune response to DNA was studied in various strains of mice F1 hybrids and corresponding back-crosses immunized with single stranded DNA complexed to methylated bovine serum albumin. Anti-DNA antibody response was measured by radioimmuno-logical technique. High responder, low responder, and intermediate responder strains were found and the ability to respond to DNA was characterized as a dominant genetic trait which is not linked to the major locus of histocompatibility. Studies in back-crosses suggested that this immune response is under multigenic control. High responder mice produce both anti-double stranded DNA and anti-single stranded DNA 7S and 19S antibodies, while low responder mice produce mainly anti-single stranded DNA 19S antibodies.     

Genetic control of the immune response to mammalian chymotrypsins in mice. II. The immune response to low doses of bovine alpha-chymotrypsin.

The immune response to the antigen bovine pancreatic alpha-chymotrypsin was investigated in ten recombinant strains of mice. Using a fixed antigen-percentage bound isotope technique, it was found that the quantity of antibody produced was related to the H-2 haplotype of the responding animal. A continuous distribution for the mean antibody responses was obtained for the ten strains of mice. High responsiveness was associated with the H-2 haplotype gamma2. The genetic control of the immune response to this immunogen was found to be both quantitative and qualitative.     

Genetic control of the immune response to mammalian chymotrypsins in mice. I. The immune response to high doses of bovine alpha-chymotrypsin.

The primary and secondary immune response to the antigen bovine pancreatic alpha-chymotrypsin was investigated in inbred mice. It was found that strain differences in the immune response only became apparent after secondary immunization. The genetic control of the immune response was investigated in twelve different strains of mice, F1, F2 and F1 backcross hybrids, following secondary immunization. A continuous distribution for the mean antibody responsiveness was obtained. High responsiveness was associated with both the H-2 haplotype and three non-H-2 loci. Furthermore the F1 hybrids produced a greater quantitative antibody response to chymotrypsin than either of the corresponding parental strains.     

Antigen dose and strain variation as factors in the genetic control of the immune response to sperm whale myoglobin.

The primary and secondary immune response to the antigen sperm whale myoglobin was investigated in DBA/2, 129 and B10.BR mice over a dose range of immunization from 10 to 2000 microgram. Using an antigen excess technique, the quantity of antibody produced after secondary immunization followed a sigmoidal dose-response curve and the maximal plateau level was found to be different for each strain of mice. Furthermore, the genetic control of the immune response was investigated in twelve different inbred strains of mice following secondary immunization with 500 microgram of myoglobin. A continuous distribution for the mean antibody responses was obtained for the twelve different strains of mice. High responsiveness was associated with H-2 haplotypes d, f and k located on chromosome 17, the non-agouti gene 'a' located on chromosome 2 and the chinchilla gene 'c(ch)' located on chromosome 7. It is concluded that either a large number of IR-genes to myoglobin are present in many loci located on different chromosomes or the antibody differences could be explained by a cross-tolerance mechanism requiring no IR-genes at all.     

Assessment of cancer immunotherapy outcome in terms of the immune response time features.

A cytokine-based periodic immunotherapy treatment is included in a model of tumour growth with a delay. The effects of dose schedule are studied in the case of a weak immune system and a growing tumour. We find the existence of 'metastable' states (that may last for tens of years) induced by the treatment and also potentially adverse effects of the dosage frequency on the stabilization of the tumour. These two effects depend on the delay between the tumour growth and the immune system response, the cytokine dose burden, and other parameters considered in the model.     

Genetic control of the immune response to staphylococcal nuclease. XI. Effects of in vivo administration of anti-idiotypic antibodies

The effects of prior treatment with heterologous anti-idiotypic antibodies on the response to staphylococcal nuclease (Nase) have been examined. Previous studies have shown that 100% of A/J mice treated with Nase in completes Freund's adjuvant produce anti-Nase antibodies possessing a characteristic idiotype (Id). Mice treated with anti-Id antibodies followed by Nase produced levels of Id equal to or greater than those of control animals treated with Nase alone. The appearance of Id in treated mice preceded the appearance of anti-Nase activity, and animals treated with anti-Id alone produced high levels of Id without detectable anti-Nase activity. Id expression in such animals could be detected using anti-Id reagents produced in several different species suggesting that it represented true idiotope expression rather than unrelated molecules reactive only with the anti-Id reagent used for initial treatment. Isolation of the nonantigen-binding Id-bearing molecules (Id') showed them to be immunoglobulins bearing the same idiotopes as do anti-Nase antibodies. However, quantitative comparisons of Id levels vs. amount of Id or Id'-bearing immunoglobulin suggested that the nonantigen-binding immunoglobulins bore fewer idiotopes per molecule than did anti-Nase antibodies. Evidence was also obtained for the production of some nonantigen-binding Id-bearing molecules during the normal immune response Nase. These findings are therefore consistent with the existence of a network of Id-anti-Id interactions in the immune response to Nase.     

Histocompatibility antigens and genetic control of the immune response in guinea-pigs. V. Evidence from further breeding studies for the polygenic control of the cellular immune response to structurally unrelated antigens in the guinea-pig.

Further breeding studies were carried out to investigate the polygenic control of the cellular immune response in the guinea-pig to low doses of aspirin anhydride (ASAN), penicilloylated bovine immunoglobulin (BPO-BGG) and to the multi-chain copolymer (T, G)-A-L. Although responsiveness to these three antigens is controlled by three independently segregating loci, at least one gene required for these responses is linked to the strain 13 haplotype.     

Genetic control of immune response in mice to derivatives of multichain polyproline differing in the optical configuration of component amino acids

The immune response of two inbred mouse strains, DBA/1 and SJL, to eight synthetic polypeptides of the general formulae, poly(Tyr, Glu)-poly Pro—polyLys and poly(Phe, Glu)-polyPro—polyLys, differing in the optical configuration of the amino acids composing the macromolecules, was compared. SJL mice responded predominantly to the polyPro—polyLys moieties of either optical configuration in the eight enantiomorphs. In both strains of mice tested, immunization with polypeptides of the formula poly(Tyr, Glu)-polyPro—polyLys leads to antibodies specific for the polyproline moiety mainly. DBA/1 mice are low responders to 701, poly(L Tyr, L Glu)-polyL Pro—polyL Lys, whereas they elicit a good immune response to polyDPro—polyDLys when immunized with 713, poly(DTyr, DGlu)-polyDPro—polyDLys, and with 711, poly(L Tyr, L Glu)-polyDPro—polyDLys. It is of interest that mice of the DBA/1 strain responded well to 715, poly(DTyr, DGlu)-polyL Pro—polyL Lys with antibodies specific to poly-L -proline. Since this polymer is metabolized slowly and incompletely similarly to antigens composed exclusively of D -amino acids, it is likely that the slow metabolism affects the ability of this mouse strain to respond to this immunogen. DBA/1 mice responded predominantly to the (L Phe, L Glu) region when immunized with 702, poly(L Phe, L Glu)-polyL Pro—polyL Lys. Since they are high responders to (L Phe, L Glu) and to polyD Pro—polyD Lys, they elicited antibodies to both immunopotent regions of 712, poly(L Phe, L Glu)-polyD Pro—polyD Lys. Although DBA/1 mice are high responders to (L Phe, L Glu) they did not respond to D -amino acid analogues of these peptides, and immunization of this mouse strain with 714, poly(D Phe, D Glu)-polyD Pro—polyD Lys, and with 716, poly(D Phe, D Glu)-polyL Pro—polyL Lys, elicited anti-polyproline antibodies only. The results of this study show that the optical configuration of the amino acids composing an antigen plays an important role in the genetic control of the ability to respond to the immunogens investigated.