Showing papers on "BALB/c published in 1982"

Protection against lethal challenge of BALB/c mice by passive transfer of monoclonal antibodies to five glycoproteins of herpes simplex virus type 2.

Abstract: Monoclonal antibodies secreted by six hybridomas and recognizing antigenic sites on glycoproteins gC, gAB, gD, gE, and gF of herpes simplex virus type 2 were examined for their ability to protect BALB/c mice from lethal infection by the virus. Administration of monoclonal antibodies to individual glycoproteins intraperitoneally 3 h before footpad challenge with 10 times the 50% lethal dose of virus protected between 35 and 75% of the mice, except for one of two monoclonal antibodies recognizing antigens on gC. The antibodies did not neutralize virus in vitro and protected A/J mice deficient in the fifth component of complement as efficiently as complement-sufficient BALB/c mice. A good correlation was found between protection and titers of monoclonal antibodies assessed by antibody-dependent cell-mediated cytolysis. The results indicate that any of the glycoproteins can serve as antigens for a protective immune response. In addition, the data are compatible with protection being mediated by an antibody-dependent cell-mediated cytolysis mechanism.

Evidence from mtDNA sequences that common laboratory strains of inbred mice are descended from a single female

Abstract: The rapid evolution1 and maternal mode of inheritance2 of mitochondrial DNA (mtDNA) make it a valuable marker for individuals related by descent from the same female3. We report here a study of wild and inbred mice which illustrates this point. We have examined mouse mtDNA from various locales in the Northern Hemisphere using restriction enzymes that cut the molecule at an average of 150 sites and find a high level of restriction-site polymorphism in wild mice but no variation among the ‘old’ inbred strains. This result is surprising because the nuclear genomes of these strains are known to differ greatly from one another4. The old inbred type of mtDNA occurs rarely in wild mice and differs from other types in the wild by an average of 100 nucleotide substitutions. In possible contradiction of published breeding records, these findings indicate that only one female lineage contributed to the formation of all the old inbred lines. In addition, our study of new inbred strains provides genetic markers that will be useful in mouse developmental and cell biology.

Lysosome lipid storage disorder in NCTR-BALB/c mice. I. Description of the disease and genetics.

Abstract: We describe a strain of BALB/c mice, designated NCTR-BALB/c, carrying a new genetic disorder characterized by excessive tissue deposition of cholesterol and phospholipid. The mice exhibit progressive incoordination, grow less rapidly, and die 80-120 days after birth. In comparison with control animals of the same age, organ weights in the affected animals are lower in absolute value but higher relative to body weight, except for the thymus, which is atrophied, and for the lung and testes, whose absolute weights are not changed. Vacuolated cells are found in many tissues, and large foam cells are present in reticuloendothelial system (RES)-rich organs. Compared with those of BALB/c controls, serum lipoproteins migrate more slowly on electrophoresis; the amount of beta-lipoproteins is increased, while alpha-lipoprotein content is decreased. Serum total cholesterol remains normal. The serum activities of aspartate aminotransferase, creatine phosphokinase, and N-acetyl-beta-glucosaminidase are elevated. Free cholesterol levels are increased 8-10-fold in liver, spleen, and thymus, and about 2-fold in other tissues; but esterified cholesterol levels are normal. The phospholipid content of several tissues is increased 50-100%, largely as a result of an increase in sphingomyelin content. Significant increases in phosphatidylcholine occur also in spleen and lung. The disorder is inherited, affecting both sexes equally, and appears to be transmitted as an autosomal recessive mutation.

Identification of a BALB/c H-2Ld gene by DNA-mediated gene transfer

Abstract: Gene transfer and immunoselection were used in the identification of a BALB/c genomic clone containing an H-2Ld gene (clone 27.5). Transformation of thymidine kinase-negative C3H mouse L cells with the cloned 27.5 DNA together with the herpes simplex virus tk gene produced transformants expressing Ld molecules detected by radioimmune assay with monoclonal hybridoma antibodies to Ld antigens. The foreign Ld gene products expressed by cloned mouse L cell transformants were shown to be virtually indistinguishable from BALB/c spleen Ld molecules by two-dimensional electrophoretic analysis of H-2Ld immunoprecipitates. These results indicate that the genomic clone 27.5 contains a functional BALB/c H-2Ld gene and demonstrate the usefulness of this approach for identifying the gene products encoded by cloned genes which are members of a multigene family. Furthermore, the ability to place cell-surface recognition molecules on the surfaces of foreign cells provides a powerful opportunity for functional analyses of these molecules.

Detection of Ductal Dysplasia in Mammary Outgrowths Derived from Carcinogen-treated Virgin Female BALB/c Mice

Abstract: These studies were undertaken to determine if altered growth potential of mammary epithelial cells could be detected in outgrowths derived from monodispersed mammary cells of virgin female BALB/c mice previously exposed to ionizing radiation or 7,12-dimethylbenz(a)anthracene (DMBA). Monodispersed mammary epithelial cells were obtained by enzymatic dissociation of mammary tissues of 12-week-old virgin female BALB/c mice. Twenty-four hr prior to cell dissociation, donor animals were exposed to either 100 rads of γ-ray irradiation, 0.25 mg of DMBA, or 0.075 mg of DMBA. Control donors were untreated. Mammary outgrowths were then derived from these donor cells by injecting either 105 or 104 cells into the gland-free mammary fat pads of three-week-old virgin female BALB/c mice. Ten weeks after the injection of cells, the outgrowths were examined and classified. Mammary outgrowths were classified either as having a normal ductal architecture or as having ductal dysplasia. Ductal dysplasias were further classified on the basis of an index of severity, which was an arbitrary index based on the number of abnormal ductal structures within each lesion. The data indicated that treatment of donor animals with either γ-radiation or DMBA increased the frequency of ductal lesions over control levels; however, both the frequency and severity of the lesions depended on the number of cells which were injected into the fat pad. When outgrowths were derived by injection of 105 cells into the gland-free fat pads, lesion frequencies in outgrowths from control and treated cells were: 3.3%, control; 15.7%, γ-rays; 5.3%, 0.25 mg DMBA; in these groups only a few severe lesions were detected. In outgrowths derived from 104 cells, less severe lesions (Class I lesions) were common in all groups and occurred in approximately 10 to 15% of the outgrowths. The frequency of severe (Class II and III) ductal dysplasia, however, was increased by treatment in these groups, occurring in 4.5% of control outgrowths in 15.6, 14.9, and 14.3% of the outgrowths derived from donor cells treated with 100 rads γ-rays, 0.075 mg DMBA, and 0.25 mg DMBA, respectively. Thus, these data indicated that ductal dysplasias were more common and more severe in outgrowths derived from 104 rather than 105 cells. The ductal lesions observed in this study resembled both morphologically and histologically ductal abnormalities which have been associated with the pathogenesis of mammary carcinoma in both rats and mice.

Histocompatibility and isoenzyme differences in commercially supplied "BALB/c" mice.

Abstract: BALB/c mice obtained commercially were found to differ significantly from the standard phenotype of BALB/c strain mice. Isoenzyme tests and H-2 haplotype analyses indicated that the majority of mice from two of the three sources tested appeared mixed, frequently heterozygous, and did not consistently express either the expected H-2 or glucose phosphate isomerase type.

Selected mutants of mouse hepatitis virus type 4 (JHM strain) induce different CNS diseases. Pathobiology of disease induced by wild type and mutants ts8 and ts15 in BALB/c and SJL/J mice.

Abstract: The model system of central nervous system (CNS) disease induced by mouse hepatitis virus type 4 (MHV-4) is explored by comparison of wild type (wt) MHV-4 and two temperature-sensitive (ts) mutants, designated ts8 and ts15, in BALB/c and SJL/J mice In BALB/c mice, 3 plaque-forming units (PFU) of wt MHV-4 given intracerebrally caused fatal encephalomyelitis in all mice by 7 days after infection, with spread of virus outside the CNS, especially to liver In SJL/J mice, 3 PFU of wt virus was cleared within 2-3 days, with little spread, and up tp 100 PFU failed to cause fatal encephalomyelitis However, larger amounts of virus, like 1000 PFU, caused fatal encephalomyelitis in SJL/J mice In contrast, 10(4) PFU of MHV-4 ts8 did not cause death in either BALB/c or SJL/J mice, and persisted in the CNS of both strains while retaining its ts phenotype There was significatnly less spread of virus outside the CNS BALB/c mice usually showed demyelination, remyelination, and recurrent demyelination with ts8, while SJL/J mice only rarely had lesions Intracerebral inoculation with 10(4) PFU of MHV-4 ts15 was associated with a persistent infection in CNS and liver of BALB/c mice; however, only occasional demyelination and hepatic lesions occurred TS15 did not cause death in either BALB/c or SJL/J mice and did not cause histopathologic injury in SJL/J mice

Natural cell-mediated cytotoxicity in vitro and inhibition of tumor growth in vivo by murine lymphoid cells cultured with T cell growth factor (TCGF).

Abstract: Lymphoid cells obtained from the spleen, thymus, bone marrow, peripheral blood, and peritoneal exudate of normal mice (BALB/c, BALB/c nude, C57BL/6, C3H) and from spleens of mice bearing a transplantable lung carcinoma or primary mammary carcinoma were expanded in culture for 1–9 months, with an increase in cell number of 105- to 106-fold per month, in crude or lectin-depleted medium containing T cell growth factor (TCGF). All these cultured lymphoid cell (CLC) lines exhibited strong cytotoxic activity in vitro (assessed by 51Cr-release assays) toward a variety of freshly harvested and cultured syngeneic, allogeneic, and xenogeneic tumor target cells, both lymphoid and solid (including metastatic growths) in origin. Extensive killing was observed against tumor targets that were resistant to lysis by natural killer (NK) cells as well as to NK-sensitive tumor lines. Low levels of cytotoxic reactivity were also demonstrated against fresh and cultured normal lymphoid cells. The CLC had some characteristics of NK cells but also expressed some typical T cell markers. In local Winn-type neutralization assays, CLC delayed or completely inhibited the growth of lymphomas and carcinomas in syngeneic and allogeneic recipients. In mice with metastatic growth of a second-generation transplant of mammary carcinoma, CLC were shown to have some therapeutic effect when administered IV 1 day after cyclophosphamide. No significant beneficial action of IV administered CLC was observed in the absence of chemotherapy in mice implanted with a lung carcinoma. The possibilities of employing TCGF-propagated cytotoxic effector cells in adoptive immunotherapy of human malignancies are discussed.

Immune response against the T-independent antigen alpha (1 leads to 3) dextran. I. Demonstration of an unexpected IgG response of athymic and germ-free-raised euthymic BALB/c mice.

Abstract: The primary antibody response in BALB/c mice to the T-independent bacterial antigen dextran B1355S [alpha(1 leads to 3)dextran] (Dex) was studied by means of isoelectric focusing, hemagglutination and immunodiffusion techniques. In response to a single immunization with 10 micrograms Dex all mice produce specific IgM antibodies. In addition, about 30% of conventionally raised BALB/c and BALB/c nu/ + mice, but 95% of germ-free (GF)-raised normal BALB/c and 100% of athymic BALB/c nu/nu mice produce specific IgG class anti-Dex antibodies. These antibodies include all IgG subclasses, carry predominantly the lambda light chain and the cross-reactive J558 idiotype and are specific for the alpha(1 leads to 3)glucosidic linkage. As compared to athymic and GF-raised mice, conventionally raised mice exhibit only a weak IgG response. The pronounced IgG production of GF-raised mice was not altered when adult mice were removed from their GF environment and housed under conventional conditions for several weeks prior to immunization with Dex. Reconstitution with isolated splenic T cells from conventionally raised, unprimed BALB/c mice reduces the remarkable capacity of BALB/c nu/nu mice to produce IgG anti-Dex antibodies. These findings suggest that the reduced capacity of conventionally raised BALB/c mice to mount an IgG response to the T-independent antigen Dex is due to a T cell-mediated suppressive mechanism which is neonatally induced by contact with environmental, i.e. bacterial, antigens.

Regulation of azophenylarsonate-specific repertoire expression. 1. Frequency of cross-reactive idiotype-positive B cells in A/J and BALB/c mice.

Abstract: A large proportion of p-azophenylarsonate (ARS)-specific antibodies from A/J mice share a cross-reactive idiotype (CRIA) that comprises a family of closely related but nonidentical clonotypes. I determined that only 2.6 % (7 out of 267) A/J ARS-specific monoclonal antibodies generated in the splenic focus system possess the predominant CRIA. Because ARS-specific B cells are present at a frequency of 1/68,000 B cells, the frequency of the entire idiotype family is 1 per 2.8 X 10(6) splenic B cells. Thus, there is a striking discrepancy between the representation of this idiotype at the clonal precursor cell level and the serum antibody response. In addition, BALB/c mice have the potential to generate CRIA-positive precursor cells within their nonimmune repertoire. When A/J mice are immunized with ARS-protein conjugates, the serum antibody response and precursor cell population are both dominated by CRIA. The frequency of CRIA-positive B cells increases over 100-fold after immunization, whereas CRIA-negative precursor cells may initially decrease, followed by a later rise in frequency. Finally, although ARS-specific precursor cells are present in high frequency at birth, CRIA-positive monoclonal anti-ARS antibodies are not observed during the early neonatal period. These data provide evidence to suggest that complex regulatory networks influence precursor cell and serum antibody expression.

Regulation of immune responses aginst the syngeneic ADJ-PC-5 plasmacytoma in BALB-c mice. III. Induction of specific T suppressor cells to the BALB/c plasmacytoma ADJ-PC-5 during early stages of tumorigenesis.

Abstract: Initial stages of tumour growth are not easily accessible to investigation. Therefore an experimental procedure was developed to mimic tumorigenesis as closely as possible. BALB/c mice received intraperitoneally exponentially increasing numbers of irradiated syngeneic ADJ-PC-5 plasmacytoma cells. The initial injection began with two cells per mouse and according to the generation time of this tumour, subsequent doses were doubled until mice had received up to 10(5) tumour cells. At various stages of treatment, peritoneal exudate cells (PEC) and spleen cells (SC) were tested for either cytotoxicity or specific suppression of induction of a primary in vitro T-cell cytotoxic response (CTL) of BALB/c spleen cells against ADJ-PC-5 plasmacytoma cells. No cytotoxic PEC were found. Instead, PEC from mice in which the final tumour cells number had reached or exceeded 10(3) irradiated ADJ-PC-5 cells, induced complete suppression of this primary in vitro CTL. Specificity was found both in the induction and effector phase of suppression. Specific suppression was mediated by Thy-1.2+ cells and amplified by non-specific suppression through adherent cells. The data arae discussed in context with previous findings on the in vivo immunogenicity and tolerogenicity of the ADJ-PC-5 plasmacytoma. They suggest that induction of T suppressor (Ts) cells might be an early event in tumorigenesis.

Induction of mammary tumors in virgin female BALB/c mice by single low doses of 7,12-dimethylbenz(a)anthracene

Abstract: The induction of mammary tumors in virgin female inbred BALB/c mice after administration of 7,12-dimethylbenz[a]anthracene (DMBA) over a wide range of doses was studied. Mice were exposed at 12 weeks of age to single or multiple doses of DMBA ranging from 0.0025 to 12.0 mg by gastric intubation and were checked regularly for mammary tumors. The experiment was terminated when the mice were 800 days of age. In the dose range of 0.0025--0.125 mg DMBA, the incidence of mammary tumors was dose-dependent. At higher doses, the mammary tumor incidence became less dose-dependent and was nearly independent of doses above the 0.25-mg level. Analysis of the data for the rate of appearance of mammary tumors with age of the animals and for the age at death of non-mammary tumor-bearing animals indicated that in the low dose range induction of mammary tumors was the predominant effect of DMBA exposure, whereas at moderate to high doses the toxic and carcinogenic effects of DMBA on other tissues significantly influenced the final incidence of mammary tumors. Greater than 90% of the tumors that resulted from administration of low doses of DMBA were adenocarcinomas. In contrast, adenocarcinomas and adenoacanthomas were found in approximately equal proportions following administration of high doses of DMBA.

Cross-reactions between tumor cells and allogeneic normal tissues. Inhibition of a syngeneic lymphoma outgrowth in H-2 and non-H-2 alloimmune BALB/c mice.

Abstract: To test whether alloimmunization with H-2 or/and non-H-2 different normal tissues may increase the immunity to syngeneic tumors, groups of BALB/c (H-2d) mice were immunized with a series of allogeneic lymphoid cells and then challenged i.p. with syngeneic lymphoma cells. The outgrowth of otherwise lethal doses of the Moloney virus-induced lymphoma YC8 and of its clones was inhibited in BALB/c mice immune to DBA/2 (H-2d), C3Hf (H-2k), C3H.SW (H-2b), C3H.OH (H-2o2) and to B10 background tissues but not in mice immunized to A/He, BALB.K (H-2k) or BALB.B (H-2b) normal tissues. Anti-YC8 effect was also induced by immunizing BALB/c recipients with a pool of five different allogeneic cell lines which included C3Hf, C57BL/6J (H-2b), N:NIH (H-2q), B10.M (H-2f), and DBA/2 lymphoid cells. No growth inhibition of other BALB/c lymphomas induced by Moloney virus (LSTRA), X-rays (RL male I) or urethane (UR-1) was evident in alloimmune mice. In vivo transfer of growth inhibition of YC8 was obtained with BALB/c anti-B10.D2 peritoneal exudate cells in a Winn assay. The ability of these alloimmune lymphoid cells to delay significantly the survival time of BALB/c mice injected with the mixture of immune cell and YC8 cells was abrogated by anti-Thy 1.2 plus C' treatment. In addition, nu/nu BALB/c mice were unable to develop resistance to YC8 outgrowth after alloimmunization. The results of this study show that: (1) syngeneic growth of a lymphoma can be prevented by alloimmunization with normal cells; (2) this cross-reaction involved non-H-2 antigens; (3) the phenomenon appeared to be mediated by T cells.

Resistance to L1210 Mouse Leukemia Cells in Moderately Protein-malnourished BALB/c Mice Treated in Vivo with Thymosin Fraction V

Abstract: Moderate protein malnutrition retarded the i.p. proliferation of L1210 mouse leukemia cells in BALB/c mice. The increased resistance against leukemia cell growth in protein-malnourished mice was correlated with increased in vitro mitogenic responsiveness of spleen lymphocytes to phytohemagglutinin and increased levels of serum corticosterone but could not be correlated with altered development of splenic lymphocyte-mediated cytotoxicity. The increased resistance against leukemia cells in well-fed mice treated with thymosin alone could not be correlated with an increase in any of these parameters. Treatment with Thymosin Fraction V further increased the resistance of protein-malnourished mice to i.p. leukemia cell growth. The increased resistance of these mice to tumor cell growth was correlated with increased splenic lymphocyte mitogenic responsiveness to phytohemagglutinin, elevated serum corticosterone levels, and a slight increase in lymphocyte-mediated cytotoxicity 14 days after tumor challenge. For 7 days after the last treatment, protein-malnourished mice had reduced serum corticosterone levels. Nevertheless, the serum corticosterone levels were still higher than normal in these mice.

Allergic hypersensitivity to the herbicide 2,4-D in BALB/c mice.

Abstract: Following several reports of human allergic hypersensitivlty, the ability of 2,4‐D (2,4‐dichlorophenoxyacetic acid) to elicit 2,4‐D‐specific IgE antibodies and delayed‐type hypersensitivity in BALB/c mice was studied. 2,4‐D‐specific IgE antibodies were detected in mouse sera following the second intraperitoneal immunization with I, 10, or 100 μg 2,4‐D‐keyhold limpet hemocyanin conjugate with aluminum hydroxide adjuvant. Specific IgE was determined with the rat passive cutaneous anaphylaxis test using a conjugate of 2,4‐D with bovine serum albumin for challenge. The highest antibody titers and a measurable response in all mice were seen in the group that received 1 μg of 2,4‐D conjugate. Dinitrophenyl‐specific IgE was measured at all intervals examined in mice immunized with a dinitrophenyl‐keyhole limpet hemocyanin conjugate. 2,4‐D applied epicutaneously on 2 d or over 4 wk failed to elicit delayed‐type hypersensitivity as measured by change in ear thickness, incorporation of 5‐[125 I] iodo‐2'‐deoxyuridin...

Immunomodulating effects of 13-cis retinoic acid on the igg and igm response of balb/c mice.

Abstract: The results reported here provide information on the effects of 13-cis retinoic acid (13-cRA) on the IgG and IgM responses in BALB/c mice. For these studies, a suboptimum immunizing concentration of ovalbumin (1 microgram) was used. BALB/c mice were given either 13-cRA or control beadlets (gel) as either 1 dose (at day -1) or 4 doses (at week -3, -2, -1, and day -1) prior to primary immunization, or 4 doses prior to, and 4 doses after, primary immunization (week -3, -2, -1, day -1, week 1, 2, 3, and day 27). The results consistently showed no primary antibody response and excellent secondary antibody levels in all 13-cRA-treated groups. Attempts to determine whether the 13-cRA affected the afferent or efferent phase of antibody induction by varying the time of the administration of a single 13-cRA dose, relative to immunization, showed no difference in the results in animals treated on day -2 to day 3.

Macrophages in resistance to rickettsial infection: strains of mice susceptible to the lethal effects of Rickettsia akari show defective macrophage Rickettsicidal activity in vitro.

Abstract: Activation of macrophages was assessed in strains of mice inoculated intraperitoneally with 1,000 times the 50% lethal dose of Rickettsia akari. Macrophages from mice resistant to R. akari infection (C3H/HeN, C57BL/10J, and BALB/cN) were nonspecifically tumoricidal 2 to 4 days after rickettsial inoculation. Moreover, these macrophages were microbial for R. akari in vitro; cells were resistant to infection with the bacterium and were capable of killing intracellular rickettsiae. In contrast, macrophages from strains of mice susceptible to R. akari (C3H/HeJ, C57BL/10SnCR, and A/J) failed to develop nonspecific tumoricidal activity over the course of lethal disease and became infected with R. akari in vivo within 2 days of rickettsial inoculation. Macrophages from uninfected mice of strains susceptible to R. akari also could not be activated for rickettsicidal or tumoricidal activities by treatment with macrophage-activating agents (Mycobacterium bovis BCG) in vivo or by treatment with lymphokines in vitro.

NK-2.1: an NK-associated antigen detected with NZB anti-BALB/c serum.

Abstract: NZB/B1NJ mice immunized with BALB/c spleen cells produced antibodies to an NK-associated antigen(s). Antisera without detectable autoantibody lysed fewer than 5% of BALB/c spleen cells (SC) but mediated C-dependent depletion of Nk cell activity, as measured in a /sup 51/Cr-released assay with YAC-1 targets. To determine if NZB anti-BALB/c antibodies recognized an allele of the previously described locus NK-1, 136 (BALB/c x NZB)F/sub 2/ progeny were screened for sensitivity to NZB anti-BALB/c serum and anti-NK 1.1 (BALB/c x C3H F/sub 1/ anti-CE serum) and C. Segregation analysis of anti-sera sensitivity and coat color phenotype of 63 (BALB/c x NZB)F/sub 2/ indicated that sensitivity to NZB anti-BALB/c serum was linked to the agouti(a) locus on chromosome 2. Based on these data, the authors designate the antigen detected by NZB anti-BALB/c serum as NK-2 and the activity of the serum as anti-NK-2.1. Eighteen strains were tested for reactivity with anti-NK 2.1 and anti-NK-1.1. Nine were NK-1.1/sup +/, NK-2.1/sup -/, six were NK-1.1/sup -/, NK-2.1/sup +/. NK-2.1/sup +/ cells, selected with the fluorescene-activated cell sorter, were enriched in NK activity compared to NK-2.1/sup -/ SC.

Spontaneous Hyperglycemia and Impaired Glucose Tolerance in Athymic Nude BALB/c Mice

Abstract: Basal plasma glucose, glucose tolerance, and insulin secretion were investigated in young and mature athymic nude BALB/c mice and in age-matched controls. Basal plasma glucose levels in male athymic nude mice were similar to those of controls at 1, 3, and 4 wk of age. At 6, 8, and 12 wk of age, male athymic nudes had significantly higher basal plasma glucose levels when compared with controls (P less than 0.01). Plasma immunoreactive insulin concentrations were similar in athymic nudes and controls at 1 wk of age, but at 3 wk of age and subsequently at 6, 8, and 12 wk athymic nude mice had significantly decreased insulin levels when compared with their age-matched controls (P less than 0.05). We found impaired glucose tolerance in male athymic nude mice at all age groups when compared with both female athymic nudes and control BALB/c mice. The discovery of a spontaneous diabetic syndrome (hyperglycemia, impaired glucose tolerance, and decreased insulin secretion) in a colony of athymic nude mice may provide an excellent model for studying the genetics and interactions between the immune and endocrine systems.

Cross-reactivity of the NPa and NPb idiotypic responses of BALB/c and C57BL/6 mice to (4-hydroxy-3-nitrophenyl)acetyl (NP).

Abstract: A comparative antigenic analysis was carried out to determine whether cross-reactivity exists between the major idiotypic responses to (4-hydroxy-3-nitrophenyl)acetyl (NP) in BALB/c and C57BL/6 mice. Extensive cross-reactivity exists between the NPa (BALB/c) and NPb (C57BL/6) allotype-linked idiotypic responses to NP. The cross-reactive determinants of the NPb idiotype are confined to one particular group of NPb-positive monoclonal antibodies. The extent of cross-reactivity between this group of C57BL/6 antibodies and idiotype-positive monoclonal antibodies of BALB/c is so great that they cannot be readily distinguished as NPb- or NPa-positive antibodies with polyclonal anti-idiotypic reagents. That this cross-reactivity is not unique to monoclonal antibodies was confirmed by the demonstration of these cross-reactive determinants in the immunesera of individual BALB/c and C57BL/6 mice. Additionally, evidence was obtained from these experiments and from earlier ones from this laboratory which suggests that the BALB/c idiotypic response to NP-protein conjugate is more homogeneous than the C57BL/6 idiotypic responses.

Complement does not play a role in promoting Babesia rodhaini infections in Balb/C mice.

Abstract: A critical role of C3 and the C3b receptor for the erythrocyte invasion and the development of the parasitemia of B. rodhaini in rats has been described recently (Jack and Ward 1980a). In the present study the influence of the C system on B. rodhaini infection in Balb/C mice is documented. Depletion of serum C3 to less than 5% of the normal level by treatment of mice with CoF, the C3 inactivator isolated from cobra venom, did not affect the course of B. rodhaini parasitaemia. Treatment of mice with trypan blue, a reagent that inactivates the C3b receptor on human polymorphonuclear leukocytes, inhibited the development of parasitemia. However, when B. rodhaini parasitized erythrocytes were incubated in vitro with trypan blue and subsequently tested for the in vivo and in vitro replication of the parasites, this old-fashioned therapy for babesiosis in cattle showed its babesiacidal activity. This indicates that the inhibition of parasite development by trypan blue is caused by its parasitotoxicity. These data suggest that the C system does not play an essential role in the development of B. rodhaini infection of the Balb/C mouse.

Molecular heterogeneity of D-end products detected by anti-H-2.28 sera. I. A. molecule similar to Qa-2, detected in the BALB/cBy but not in the BALB/c-H-2dm2 mutant.

Abstract: Immunoprecipitation of NP-40 lysates of 125I-labeled lymph-node cells with different anti-H-2 sera and with anti-Qa-2 serum has shown that the BALB/cByA strain (H-2d, Qa-2-negative) expresses, besides H-2Ld, another molecule that is not detectable in the BALB/c-H-2dm2 strain. Electrophoresis in SDS polyacrylamide gels indicated that this molecule, provisionally designated Lq, has an apparent molecular weight of 41000 daltons, in contrast to approximately 49000 daltons for H-2Kd and H-2Ld, and 47000 daltons for H-2Dd molecules. The anti-Qa-2 serum precipitated from the Qa-2-positive strains BALB/cHeA but not from the Qa-2-negative strains BALB/cByA and BALB/c-H-2dm2 a protein that gave a very strong band corresponding to the molecular weight 41000 daltons in the gel electrophoresis. The biochemical characteristics of the Lq molecule are thus more similar to those of Qa-2 than of H-2 antigens.