B10 Congenic Strains Research Articles

Influence of H2 complex and non-H2 genes on progression of cutaneous lesions in mice infected with Leishmania amazonensis

Susceptibility to infection with Leishmania amazonensis promastigotes was examined in six B10 congenic mouse strains, including C57BL/10J (H2b), B10.BR (H2k), B10.M (H2f), B10.S (H2s), B10.RIII (H2r), and B10.D2 (H2d). All strains of mice developed skin nodules with punch-out ulcers by 8 weeks post-infection, but B10.M and B10.S mice showed resolution of cutaneous leishmaniasis lesions by 16 weeks post-infection. In addition, the skin lesions were much larger in BALB congenic mice than in B10 and C3H mice, even though these mice share the same H2 haplotypes. These results suggest that H2 complex controls the growth of L. amazonensis in cutaneous lesions, and that non-H2 genes inherited by BALB congenic mice have a more potent role than the H2 complex in lesion progression.

Antibody responses and protection against influenza virus infection in different congenic strains of mice immunized intranasally with adjuvant-combined A/Beijing/262/95 (H1N1) virus hemagglutinin or neuraminidase

Antibody (Ab) responses and protection against influenza virus infection in mice immunized intranasally with hemagglutinin (HA) or neuraminidase (NA) purified from the A/Beijing/262/95 (A/Beijing) (H1N1) virus were compared among B10 congenic mouse strains. Mice were immunized intranasally with 0.1, 0.3 or 1 μg of HA or NA together with the cholera toxin adjuvant, and then boosted intranasally with 0.3 μg of the adjuvant-combined HA or NA 4 weeks later. Two weeks after the second immunization, the mice were challenged by an infection of the upper respiratory tract with the homologous virus. After 3 days, nasal wash and serum specimens were collected for virus and Ab titration. The HA immunization induced HA-specific IgG Ab responses against A/Beijing HA, which depended on the H-2 haplotype of the strain: The B10.A (H-2 a), B10.D2 (H-2 d), B10.BR (H-2 k) and B10 (H-2 b) strains were the highest, high, intermediate and low responders, respectively. The nasal IgA responses were induced in the B10.A, B10.D2 and B10.BR strains, but not in the B10 strain. In parallel with Ab responses, the B10.A, B10.BR and B10.D2 strains were conferred significant protection at any dose of primary immunization, but the B10 strain was provided protection only at 1 μg of HA. On the other hand, the NA immunization induced NA-specific Ab responses, which depended on the the H-2 haplotype of the strain: the B10.A, B10.D2, B10 and B10.BR strains were the highest, high, intermediate and low responders, respectively. In parallel with Ab responses, all the strains were conferred significant protection at any dose of primary immunization. These results indicate that the MHC-restricted responsiveness of mice to HA is different from that to NA, suggesting that the use of high-HA dose or NA as a component of the nasal influenza A (H1N1 subtype) virus vaccine improves the protective efficacy against influenza among low responder populations.

Major histocompatibility complex restriction between hematopoietic stem cells and stromal cells in vitro.

We have previously found that a significant number of hematopoietic progenitors accumulate in engrafted bones with the same major histocompatibility complex (MHC) as the transplanted bone marrow cells. In the present study, to further clarify the MHC restriction between hematopoietic stem cells (HSC) and microenvironment, we carried out cobblestone colony formation assays by culturing HSCs with MHC-matched or -mismatched stromal cell monolayers. The formation of cobblestone colonies under MHC-mismatched stromal cells significantly decreased in comparison with MHC-matched stromal cells. However, the decrease in cobblestone colony formation under MHC-mismatched stromal cells was not significant when using MHC class I-deficient HSC or stromal cells. Taken together with the results using B10 congenic strains, it is suggested that the MHC preference is restricted by MHC class Ia molecules. Treatment with monoclonal antibodies (mAbs) against MHC class Ia molecules of stromal cell phenotypes significantly enhanced the cobblestone colony formation, whereas treatment with mAbs against HSC phenotypes significantly inhibited it. The expression of cytokines to promote hematopoiesis was enhanced by the mAbs against stromal cell phenotypes. The enhancement of cytokine expression was also observed when stromal cells and HSCs were MHC-matched. These results suggest that signaling via the MHC molecules augments stromal cell activity and elicits the MHC restriction.

The mouse H-2A region influences the envelope gene structure of tumor-associated murine leukemia viruses.

C57BL/10 (B10) strains congenic at the mouse major histocompatibility locus (H-2) were injected with a modified ecotropic SL3-3 murine leukemia virus (MuLV) to determine the effect of the H-2 genes on the envelope gene structure of recombinant MuLVs. All tested strains rapidly developed T-cell lymphomas, and recombinant proviruses were detected in the tumor DNAs by Southern blot. The B10.D2 (H-2d), B10.Br (H-2k), B10.Q (H-2q), and B10.RIII (H-2r) strains exhibited a TI phenotype in which almost all tumors contained type I recombinants. These recombinants characteristically acquire envelope gene sequences from the endogenous polytropic viruses but retain the 5' p15E (TM) gene sequences from the ecotropic virus. The parental B10 (H-2b) strain, however, had a novel phenotype that was designated NS for nonselective. Only 30% of the B10 tumors had detectable type I recombinants, whereas a proportion of the others appeared to contain type II recombinants that lacked the type I-specific ecotropic p15E gene sequences. Studies of other B10 congenic strains with hybrid H-2 loci and selected F1 animals revealed that the NS phenotype was regulated by a dominant gene(s) that mapped to the A region of H-2b. These results demonstrate that a host gene within the major histocompatibility complex can influence the genetic evolution of pathogenic retroviruses in vivo.

T-Cell Epitope Mapping the PorB Protein of Serogroup BNeisseria meningitidisin B10 Congenic Strains of Mice

T-cell epitope mapping the meningococcal serotype 15 PorB protein performed in this study in three congenic strains of mice with B10 genetic background revealed at least three murine T-cell epitopes (55–72, 163–180, and 226–261), located in the highly conserved putative transmembrane regions of Neisserial porins. Proliferation assays with popliteal lymph node cells derived from mice immunized with the PorB protein or with synthetic 18-mer peptides showed that epitope 163–180 immunized only in the H-2dhaplotype, epitope 55–72 could be presented by both H-2fand H-2smolecules, while the 226–261 region covered by three overlapping peptides could be efficiently recognized in context of all three MHC class II haplotypes studied. Inhibition experiments with blocking I-Aα- and I-Eα-specific mAb showed that peptide 163–180 was presented by I-Adand peptide 244–261 was presented by both I-Afand I-As. In addition, evidence was obtained that peptide 226–243 was presented in context of H-2dor I-Ashaplotypes and peptide 55–72 was presented in context of I-Afand I-Asloci. Finally, the Norwegian outer membrane vesicle vaccine, but not the purified PorB protein, could recall responses in mice immunized with synthetic peptides corresponding to the 226–261 region. Altogether, these results suggest that T-cell epitopes identified on the serotype 15 PorB protein, particularly those presented by several MHC class II molecules (e.g., 226–261), could have important implications for the development of meningococcal vaccines.

Effects of Interferon Gamma on the Antibody Response to Pseudomonas aeruginosa Lipopolysaccharide in Mice

Different strains of mice were examined for the capacity to produce an Ig subclass-specific antibody response to purified Pseudomonas aeruginosa lipopolysaccharide (PALPS). With the exception of the AKR strain, the predominant isotype for most of the strains tested was IgG3 whereas the least frequent isotype expressed was either IgG2b or IgGl. AKR mice were unique in that the predominant isotype produced was IgG2a, rather than IgG3; however, the administration of anti-interferon gamma antibody, at the time of immunization with PALPS caused a substantial decrease in the IgG2a antibody response. Selected B10 congenic strains were used to assess the relationship between the antibody responses and the major histocompatibility complex (MHC) genes. Here, the isotype-patterns for the antibody responses were essentially the same regardless of the MHC haplotype. Interestingly, an increase in IgG2a, with a concomitant decrease in IgM and IgG1 antibody was noted when C3H mice were given interferon gamma at the time of immunization. These studies indicate that, in general, the antibody response to PALPS consists of IgG3 antibody as the predominant isotype, and that the antibody response can be modified by interferon gamma.

Effect of H-2 Compatibility in Autoimmune Destruction of Islet Allografts from B10 Congenic Lines to Nonobese Diabetic Mice

Autoimmune diabetes involves multiple antigens, and both cellular and humoral immune responses. Using CBA (H-2k) C57BL/6 (H-2b), and BALB/c (H-2d) newborn mouse pancreata, we previously demonstrated that acute and strong destruction of islet allografts by anti-islet autoimmunity in the nonobese diabetic (NOD) mouse H-2Kd, Db) is under the influence of major histocompatibility complex (MHC) antigens. In the current study, we have attempted to confirm these results in the absence of minor alloantigenic differences using B10 congenic strains as pancreatic donors. Pancreata from B10.BR (H-2k), C57BL/10SnJ (H-2b), and B10.D2 (H-2d) were transplanted under the kidney capsule of NOD mice within 1 month of diabetes onset. These recipients were immunosuppressed with cyclosporine (CsA) in a dosage that effectively prevents rejection of skin allograft, but not islet isograft destruction that is mediated by anti-islet autoimmunity. On day 10, the grafts were harvested and examined histologically to assess viability. Pancreatic allografts from B10.D2, sharing the H-2Kd with the NOD mouse, showed the strongest lymphocytic infiltration, and neither islets nor beta cells were found in all seven grafts. C57BL/10SnJ grafts, sharing the same H-2Db, also showed severe lymphocytic infiltration, and no intact islets, and only a few beta cells were found, as single cells, in three of eight grafts. In contrast, B10.BR grafts, completely incompatible at the H-2, showed the least infiltration, and normal islets containing many beta cells were found in 10 of 11 grafts. These results again suggested the hypothesis that islet allograft destruction by diabetic NOD mice is MHC restricted.(ABSTRACT TRUNCATED AT 250 WORDS)

Host genetics and resistance to acute Trypanosoma cruzi infection in mice. I. Antibody isotype profiles

Some strains of inbred mice survive acute infection with Trypanosoma cruzi while others die within a few weeks after infection. Mice which express B10 background genes and either the H-2q or H-2d haplotypes are resistant and survive. However, mice which share the B10 genetic background but express H-2k alleles die, usually within 4 weeks following infection. These data confirm that at least 1 gene in the major histocompatibility complex can determine whether an animal lives or dies during the acute phase. Expression of the H-2q haplotype on the B10 genetic background or in DBA/1 mice is associated with resistance, but H-2q mice expressing the C3H background are susceptible. Therefore, at least 1 gene in the genetic background also influences resistance. Our data suggest that genes associated with resistance must be present in both the MHC and the genetic background or the animal will die. The isotypes and specificities of parasite reactive antibodies found in the serum of different inbred mouse strains were assessed during acute infection. Levels of IgM were higher in sera from mice which express the resistant B10 background than in sera from mice expressing the susceptible C3H background. Conversely, mice which share the C3H background genes produced high levels of anti-parasite IgG2a when compared to B10 congenic strains. Antigen specificity, however, may be influenced by both background and MHC genes, as congenic strains expressing different MHC haplotypes recognized different constellations of T. cruzi antigens.(ABSTRACT TRUNCATED AT 250 WORDS)

Resistance to ectromelia virus infection in mice Analysis ofH-2-linked gene effects

The mechanism for resistance to ectromelia infection has been investigated in B6 and B10 congenic strains of mice which carry different alleles at the H-2 major histocompatibility locus. Greater susceptibility in some B10 congenic strains of mice has been associated with higher viral titres in the draining popliteal and inguinal lymph nodes as well as spleen at 3 days post infection. T cells which develop cytotoxic function following in vitro culture in the presence of T cell growth factors have also been detected in the popliteal lymph nodes of B6/B10 congenic strains of mice as early as 3 days post infection. Greater cytotoxicity has been detected in cultures of cells from resistant B6/B10 mice than from the susceptible B10 congenic strain B10.G, or other semi-resistant B10 congenic strains which differ at the H-2 locus. The early activation of T cells appears to be under H-2 gene control and activated T cells may play an "early" role in controlling viral replication within the lymphoid system.

A polymorphic microsatellite in the tumor necrosis factor alpha promoter identifies an allele unique to the NZW mouse strain.

We have amplified a (CA)n:(GT)n microsatellite from the TNF promoters of a panel of mouse strains using the polymerase chain reaction. The length of the microsatellites was polymorphic, with eight alleles observed among 15 inbred strains bearing seven distinct H-2 haplotypes, and four outbred strains. In B10 congenic strains, the TNF allele detected by microsatellite polymorphism segregated with the MHC, and in recombinant haplotypes (NOD, NZW), it segregated with H-2D. The TNF allele found in the NZW strain (H-2z) was distinct from those of all other haplotypes, consistent with the hypothesis that this strain may carry a genetic defect in TNF production.

Effects of the MHC on hormonal induction of mammary tumors and function of hypophyseal isografts in the mouse

While the role of the H-2 complex in the resistance to virally induced tumors has been extensively studied, little is known about its influence on the development of epithelial tumors of non-viral etiology, although such tumors are most prevalent in humans. Therefore, we analyzed the role of the H-2 complex in susceptibility to mammary tumors induced by hormonal stimulation from heterotopic hypophyseal isografts in H-2 congenic strains from C57BL/10, BALB/c, and O20/A backgrounds. This method of induction allows an assessment of the effect of H-2 genes on the function of various organs involved in this process. We found that the tumor susceptibility genes map to two segments: I-E-S, and to the right of S. The mechanisms by which the H-2 complex affects the induction of mammary tumors in C57BL/10 congenic strains seem to include an influence on several factors involved in the hormonal stimulation, because the susceptible B10 congenic strains have higher plasma levels of prolactin and the H-2 complex also affects the growth of hypophyseal isografts. Their size correlates with tumor development in individual mice in the resistant C57BL/10 congenic strains. We reported previously H-2-dependent differences in levels of the estrogen receptor in hypophysis. For this study, we measured the levels of estrogen receptors in uteri to asses the tissue specificity of this effect of H-2. However, no influence of the H-2 complex on estrogen receptor levels was observed in uteri. Strains from BALB/c and O20 backgrounds developed mammary tumors much earlier than the B10 congenic strains, indicating a strong influence of non-H-2 genes.

Differential pattern of T cell recognition of the 65‐kDa mycobacterial antigen following immunization with the whole protein or peptides

The 65-kDa stress protein from Mycobacterium bovis (Bacillus Calmette Guérin) elicited T cell proliferation and antibody responses in seven B10 congenic mouse strains with different H-2 haplotypes. To analyze T cell determinants on this antigen, seven peptides corresponding to six predicted T cell epitopes, and one defined B cell epitope were synthesized. Mice were either immunized with the whole antigen and the specificity of the response was ascertained in respect of the six peptides, or mice were immunized with seven of the peptides and tested for proliferative responses to the whole molecule. The results showed that three peptides carried epitopes to which mice responded following injection of the whole molecule and that immunization with two additional peptides could prime for in vitro stimulation with the native antigen. The latter result indicates the feasibility of generating T cell responses to "cryptic" epitopes on proteins by immunizing with peptides. The peptide-specific T cell responses were distinctly influenced by the H-2 haplotype of mouse strains. However, two peptides were recognized by several H-2-disparate mouse strains, and one peptide could be presented by both I-A and I-E molecules. Immunization with several peptides induced a cross-reactive T cell proliferative response to the homologous GroEL protein isolated from E. coli. The amount of cross-reactivity was influenced by the extent of sequence homology between mycobacterial and E. coli proteins and the major histocompatibility complex class II molecule used to present the peptide.

Influence of Lsh, H-2, and an H-11-linked gene on visceralization and metastasis associated with Leishmania mexicana infection in mice.

Visceral infection and metastatic lesion development following intravenous or subcutaneous inoculation of Leishmania mexicana amastigotes were examined in different B10 congenic mouse strains carrying alternative alleles at Lsh, H-2, or H-11. The results show that, despite a failure to observe any differences in rates of expansion of primary lesions in mice inoculated subcutaneously, each of these genes could be shown to exert some influence during visceralization and metastatic spread of L. mexicana infection. Of particular interest were (i) the continuous advantage observed throughout 160 to 200 days of infection in Lshr versus Lshs mice, (ii) the association between structural gene polymorphism at H-2 and profound visceral and metastatic spread of the parasite producing disease phenotypes akin to diffuse cutaneous leishmaniasis and post-kala-azar dermal leishmaniasis in humans, and (iii) similar effects observed in mice differing at H-11, the functional basis for which involves modified expression of major histocompatibility complex class II molecules. The results are discussed in relation to the human disease and the possibility that homologs for each of these genes regulate leishmanial infections in humans.

Genetic variation in the humoral immune responses of mice to the nematode Trichuris muris.

Genetically based differences in the antibody responses to the large intestinal nematode Trichuris muris were studied in two groups of H-2 congenic strains of mice that differed in their relative resistance to infection with this parasite. The primary antibody response to parasite excretory/secretory (E/S) antigen was predominantly an IgG response with the strains forming two distinct groups, defined by their genetic background. The more susceptible B10 genetic background mice had strikingly higher antibody levels than mice of the BALB genetic background. Superimposed upon these background effects were clearly defined influences attributable to H-2-linked genes, strains which differed genetically only at H-2 loci exhibiting differences in the kinetics of the antibody response. Only B10.G and B10.BR mice showed any great increase in IgM levels post-infection. No IgA specific to E/S antigen was detected in the peripheral circulation of any strain at any time post-infection. Antibody responses to a 40-43 kD antigen revealed clear H-2-linked gene effects, with mice sharing the H-2k haplotype (B10.BR, BALB/K) exhibiting considerably higher total antibody levels than strains expressing other haplotypes; mice of the H-2d haplotype (BALB/c, B10.D2/n) responded very weakly to this antigen. A Western blot analysis of antigen recognition by antibody revealed similarities between the mouse strains in their total antibody responses to T. muris E/S antigen. However, immunoprecipitation studies showed that in general the more susceptible B10 congenic strains had wider spectra of antigen recognition than the BALB congenics. Strains sharing the same H-2 haplotype had dissimilar antigen recognition profiles, but strains sharing the H-2b haplotype (B10, BALB/B) recognized a low mol. wt antigen (20-23 kD) not recognized by any other strain, suggesting an exclusively H-2b restriction in the recognition of this antigen. These results support the conclusion that both H-2-linked and background genes play important roles in controlling the humoral immune response to T. muris infection.

Genetic control of eosinophilia in parasitic infections: Responses of mouse strains to treatment with cyclophosphamide and parasite antigen

Lammas D.A., Mitchell L.A. and Wakelin D. 1988. Genetic control of eosinophilia in parasitic infections: responses of mouse strains to treatment with cyclophosphamide and parasite antigen. International Journal for Parasitology 18:1077–1085. Strain-dependent variation in the capacity of inbred and congenic mice to mount an eosinophilia in response to inoculation with the antigens of Mesocestoides corti, Trichinella spiralis or with Limulus haemocyanin (LCH), following pretreatment with cyclophosphamide (CY), is described. SWR, NIH, BALB/c, C3H and SJL mice were eosinophil high responder strains whereas C57 BL/10 and CBA mice were eosinophil low responder strains. Congenic strains with the B10 background (B10.S, B10.G and B10.BR) were all low eosinophil responders, although B10.G mice showed a level of response consistently above the other B10 congenic strains. Some of the gene(s) for high responsiveness appeared to be dominant, because F(In1)hybrids between high and low eosinophil response parental strains were intermediate to high responders. The strain-dependent pattern of eosinophil responsiveness to LHC or to M. corti and T. spiralis antigens, following CY pretreatment, was similar to that obtained previously following infection with either M. corti or T. spiralis, suggesting that heterogeneity in capacity to produce eosinophils operates independently of the nature of the eliciting stimulus.

A new symmetry: A anti-B is anti-(B anti-A), and reverse enhancement.

Immune system network theory leads to a new symmetry, namely that the antibodies produced in an allogeneic A anti-B immune response (where A and B are, say, two different mouse strains), should have complementary shapes to the antibodies in a B anti-A response. That is, A anti-B is anti-(B anti-A). This symmetry is due to the existence of two readily separable populations of antibodies that are present in alloantisera: anti-foreign and anti-anti-self antibodies. The theoretical basis for the symmetry is described, and results indicating the presence of anti-anti-self antibodies in each of 12 alloantisera (six made in B10-congenic strains, and six made with the unrelated chains CBA, SJL, and C57BL/6) are reported. The finding that hyperimmune alloantisera routinely contain anti-anti-self antibodies suggests that network regulation plays an important role in maintaining self-tolerance during responses to allogeneic cells. We further show that A anti-B serum absorbed against B can specifically prolong the survival of A grafts in a B strain animal. We suggest that this result can be interpreted as being due to A anti-(B anti-A) antibodies preventing B anti-A cells from rejecting the A grafts. We call this phenomenon "reverse enhancement" because it involves the converse antiserum to that used in conventional enhancement of graft survival by specific antibodies.

Allotypes of murine factor B controlled by a locus within the S region of the H-2 complex.

Bf protein was directly precipitated from a mixture of EDTA-plasma from 13 different, inbred strains and rabbit IgG anti-mouse Bf, and was isolated by SDS-PAGE. The gel pieces containing Bf protein were digested by trypsin after labeling with 125I-Na, and then peptides of Bf protein with each mouse strain were compared by two-dimensional peptide mapping. The results for the peptide patterns with the standard B10 congenic strains (all of which Bf phenotypes had been already designated as Bf.1 because of the identical isoelectric point values) revealed two distinct peptide patterns. The peptide pattern of Bf protein appeared to be identical in each of the inbred strains, but only one of the 36 spots in the fingerprint observed either with B10 or B10.BR (designated tentatively as Bf.1 (b.k.) ) was not detected in that from B10.D2 and B10.S (designated tentatively as Bf.1 (d.s.) ). The results of peptide mapping with intra-H-2 recombinant inbred strains show that this structural variant was mapped to the S region, which is direct evidence that allotypes of murine Bf are encoded by a structural gene within the MHC.

H-2-linked murine factor B phenotypes.

A hemolytic assay has been developed which is specific for Factor B (B) activity in murine EDTA-plasma. Three discrete levels of B activity were observed among B10-congenic strains. Mice with standard H-2 haplotypes, b, d, k, r, f, q, s, and u, all exhibited the same mean level of activity. However, plasma from H-2v (B10.SM) mice contained only 0.25 of that level, and those with standard haplotype H-2ja (B10.WB) or wild haplotype H-2wr7 (B10.WR) exhibited 2.5 times the H-2b (B10) basal level of activity. These differences among B10 congenic lines suggested that the activity is H-2 controlled; further tentative mapping with intra-H-2 recombinants indicated that the gene is located in the S region. A fourth phenotype was found among progeny of backcross generations between B10.BR (H-2k) and mice of subspecies Mus musculus molossinus and M. m. bactrianus. This ultra-high activity was found also to be governed by a gene very closely linked to Ss, the primary S region marker. F1 generations between disparate phenotypes yielded progeny with activity levels intermediate between the parents; progeny of parents of different strains with the same phenotype expressed B hemolytic titres equal to those of the parental strains. No differences in antigenic levels of the protein among the strains of different phenotypes could be detected by radial immunodiffusion. In mixing experiments, resultant activity levels were intermediate between the higher and the lower phenotype, ruling out independent inhibitors or activators of the reaction. These studies indicate that an H-2-linked S region-located single gene governs structural differences in allelic B molecules that lead to differences in specific activities.

Quantitation of H-2 antigen expression on hepatocytes and macrophages: evidence for an influence by strain background.

The surface concentration of H-2 complex antigens was measured by a quantitative immunoferritin labelling technique on hepatocytes and macrophages from five mouse strains with three haplotypes. The concentration of H-2 molecules was similar on macrophages from three B10 congenic strains, and the same similarity was observed on hepatocytes from the three strains. With both hepatocytes and macrophages, however, the surface concentration of H-2d molecules on BALB/c cells was about twice that on B10.D2 cells, and that of H-2k molecules on C3H/HeJ cells was about twice what we observed on B10.BR/SgSn cells. These measurements suggest a regulation of the surface concentration of H-2 complex antigens by a locus outside the MHC.

Regulation of experimental autoimmune thyroiditis: influence of non-H-2 genes.

Experiments were conducted to investigate the non-H-2 genetic effects on experimental autoimmune thyroiditis (EAT). Strains having C3H or BALB background in general produced higher autoimmune responses to mouse thyroglobulin (MTg) than the B10 or A strains. Comparisons of C3H and B10 congenic strains carrying similar H-2 haplotypes demonstrated that the C3H congenics had significantly higher MTg antibody titres and more severe thyroid damage, even when the strains carry the low responder H-2 haplotypes. These observations show that non-H-2 gene(s) influences EAT, in addition to genes in the MHC.