Showing papers on "BALB/c published in 1984"

Inhibition of 1,2-dimethylhydrazine-induced colon tumorigenesis in Balb/c mice by dehydroepiandrosterone

Abstract: Long-term administration of dehydroepiandrosterone (DHEA) to Balb/c mice significantly inhibits the rate of appearance of 1,2-dimethylhydrazine (DMH)-induced macroscopic colon and anal tumors and microscopic precursor and malignant lesions. The steroid, which has previously been shown to inhibit spontaneous breast cancer and chemically induced lung tumors in mice, may find application as a chemopreventive in individuals at high risk for developing colon cancer.

Experimental Trypanosoma cruzi cardiomyopathy in BALB/c mice. The potential role of intravascular platelet aggregation in its genesis.

Abstract: In male BALB/c mice aged 5-6 weeks inoculated three times at intervals of 15 days with 1 X 10(7) epimastigote forms of the PF strain of Trypanosoma cruzi and challenged 30 days after the last inoculation with 2 X 10(4) trypomastigote forms of the Colombia strain of T cruzi (the mice were sacrificed 80-100 days after the challenge) a cardiomyopathy very similar to that observed in the chronic phase of Chagas' disease in man develops The cardiac syndrome is characterized grossly by cardiomegaly with hypertrophy, dilatation of ventricular chambers, and thinning of the apex of the left ventricle (apical aneurysm) and microscopically by focal areas of myocytolytic necrosis and myocardial degeneration with an inflammatory response composed of mononuclear cells (predominantly macrophages and a few lymphocytes) with concurrent interstitial fibrosis and occasional myofibers containing pseudocysts In addition, aggregated platelets and occlusive thrombi were found in small epicardial and intramyocardial vessels of infected mice as compared with controls The potential role of intravascular platelet aggregation in the causation of focal myocardial necrosis and degeneration and apical aneurysm in experimental T cruzi cardiomyopathy in BALB/c mice is discussed

Regulation of resistance to leprosy by chromosome 1 locus in the mouse.

Abstract: Mice of different inbred strains vary in their resistance to intravenous infection with Mycobacterium lepraemurium (MLM). The mean survival time of MLM-infected A/J and DBA/2 mice is significantly longer than that of similarly infected C57BL/6 and BALB/c mice. The typing of AXB/BXA recombinant inbred strains (A = A/J, B = C57BL/6) for the trait of relative resistance/susceptibility to MLM revealed a perfect match with the strain distribution pattern of resistance/susceptibility to Mycobacterium bovis (BCG), the trait which is controlled by the Bcg (Ity, Lsh) locus on chromosome 1. The control, by this gene, of response to MLM was further confirmed by the demonstration that BALB/c-Bcg r congenic mice,which carry the DBA/2-derived Bcg r (resistant) allele on chromosome 1, are significantly more resistant to MLM infection than their BALB/c (Bcg s , susceptible) counterparts.

Immunopathology of experimental cutaneous leishmaniasis.

Abstract: Relatively susceptible BALB/c and relatively resistant A/J mice were infected subcutaneously in the right hind footpad with promastigotes of Leishmania mexicana amazonensis. A large localized lesion developed within 2 months after infection in the BALB/c mice, while A/J mice exhibited a small discrete fibrotic nodule. Sequential immunologic and histologic examination demonstrated that BALB/c mice developed a nodular foam-cell type of lesion and progressive depression of a delayed-type hypersensitivity (DTH) response to leishmania antigen, while the A/J mice had a mixed cellular fibrosing and encapsulating reaction and developed and maintained positive DTH responses to leishmania antigen. Anti-leishmania antibody responses were positive at similar levels in both strains. The lesions in BALB/c mice were found in bone marrow, tendon, skin appendages, and regional lymph nodes, with a tendency toward cutaneous metastases. Lesions in A/J mice remained localized. Fibrosis, focal fibrinoid necrosis, and lymphocytic and macrophagic infiltration were the outstanding features. Light and transmission electron microscopic studies indicated that no outstanding destruction of leishmanias seemed to occur within macrophages of either mouse strain. In the more resistant A/J mice, however, parasitized macrophages were frequently necrotic, and degenerating leishmanias were often seen free in the interstitial tissue. These observations help the interpretation of the histologic features, as well as the pathogenesis, of cutaneous and mucocutaneous leishmaniasis in man.

1,6-Dinitropyrene: Mutagenicity in Salmonella and Carcinogenicity in BALB/c Mice

Abstract: In tests on the carcinogenicity of 1,6-dinitropyrene [(1,6-DNP) CAS: 42397-64-8] and 1-nitropyrene [(1-NP) CAS: 5522-43-0], 0.1 mg of each compound was inoculated sc into BALB/c mice once a week for 20 weeks. In the group given injections of 1,6-DNP the first tumor appeared on day 112, and 10 of the 20 mice developed tumors at the injection site by 45 weeks after the first injection. However, no tumors were induced in any of the mice that received injections of 1-NP. All of the induced tumors were transplantable for more than five generations in male BALB/c mice. Most of the tumors showed the characteristic histologic features of malignant fibrous histiocytoma.

The mode of inheritance of a defect in lamination in the hippocampus of BALB/c mice.

Abstract: In BALB/c mice the lamination of the pyramidal cell layer of area CA3c of the hippocampus is abnormal in that early-generated neurons are superficial and late-generated neurons are deep. To determine the mode of inheritance of this strain difference, the laminar distribution of mossy fibers and hippocampal pyramidal cells was examined using the Timm's sulfide silver method in BALB/c C57BL/6 Fl and F2 hybrids, in BALB/cByJ and C57BL/6J mice which were fostered to females of the other strain before receiving their first meal, and in the CXB series of recombinant inbred strains (originally derived using BALB/c and C57BL/6 as progenitor strains). The pattern of hippocampal lamination was classified as “BALB/c-like” if pyramidal cells were present below an iwrapyramidal mossy fiber layer or as “B6-like” if only an infra-pyramidal mossy fiber layer was present. In both male and female CB6F1 and B6CF1 hybrids the distribution of mossy fibers is BALB/c-Iike. In 7 of 9 F2 hybrids the distribution was BALB/c-like a...

Complete amino acid sequence of heavy chain variable regions derived from two monoclonal anti-p-azophenylarsonate antibodies of BALB/c mice expressing the major cross-reactive idiotype of the A/J strain.

Abstract: The primary structure of A/J anti-p-azophenylarsonate (anti-Ars) antibodies expressing the major A-strain cross-reactive idiotype (CRIA) has provided important insights into issues of antibody diversity and the molecular basis of idiotypy in this important model system. Until recently, this idiotype was thought to be rarely, if ever, expressed in BALB/c mice. Indeed, it has been reported that BALB/c mice lack the heavy chain variable segment (VH) gene that is utilized by the entire family of anti-Ars antibodies expressing the A/J CRI. Recently, however, it has been possible to elicit CRIA+, Ars binding antibodies in the BALB/c strain by immunizing first with anti-CRI and then with antigen. Such BALB/c, CRIA+ anti-Ars antibodies can be induced occasionally with antigen alone. VH region amino acid sequences are described for two CRIA+ hybridoma products derived from BALB/c mice. While remarkably similar to each other, their VH segments (1-98) differ from the VH segments of A/J CRIA+, anti-Ars antibodies in over 40 positions. Rather than the usual JH2 gene segment used by most A/J CRIA+ anti-Ars antibodies, one BALB/c CRIA+ hybridoma utilizes a JH1 gene segment, while the other uses a JH4. However, the D segments of both of the BALB/c antibodies are remarkably homologous to the D segments of several A/J CRIA+ antibodies sequenced previously, as are the amino terminal amino acid sequences of their light chains. These data imply that BALB/c mice express the A/J CRIA by producing antibodies with very similar, if not identical, light chain and heavy chain D segments, but in the context of different VH and JH gene segments than their A/J counterparts. The results document that molecules that share serologic specificities can have vastly different primary structures.

Ontogeny of B cell precursors responding to alpha 1- greater than 3 dextran in BALB/c mice.

Abstract: The ontogeny of BALB/c B cell repertoire with specificity for alpha 1- greater than 3 dextran (DEX) was examined by using monoclonal anti-idiotype antibodies (MAID). Anti-DEX B cell precursors were absent from donor mice that were less than 5 days old. Precursors were first detected in mice from 5 to 11 days of age, but at a very low frequency of less than 1 in 10(8). In older mice, the frequency of anti-DEX precursors increased to approximately adult levels. Seventy-five percent of splenic foci from 5 to 11-day-old donors expressed IgA, and 70% expressed both IgM and IgA. The frequency of DEX-positive foci containing secreted IgA and IgM-IgA decreased as the age of the donors increased. The frequency of IgM-secreting foci remained constant at about 90% of DEX-positive foci regardless of donor age. The frequency of the MAID-defined cross-reactive idiotype CD3-2 and the EB3-16 idiotype changed very little in frequency with age, whereas the EB3-7 and LA4-8 idiotypes increased in frequency as donor age increased. Conversely, the SJL18-1 idiotope that was predominant at days 5 to 11 decreased in frequency relative to total DEX-positive foci as the age of the donors increased. The ratio of M104E-like and J558-like molecules from neonatal B cell precursors is reversed from that expressed by adult B cell precursors, and may reflect the preferential expansion of precursors bearing certain idiotypes by environmental antigens.

Effects of a crystalline silica on antibody production to T-dependent and T-independent antigens in Balb/c mice.

Abstract: A crystalline silica (standard quartz DQ12 with particle size μm) is able to stimulate in Balb/c mice the production of antibodies of various isotypes to the T-dependent antigen trinitrophenylated keyhole limpet hemocyanin. Under the same experimental conditions silica was not able to stimulate antibody response to the T-independent antigen trinitrophenylated Ficoll. These results support the possibility that adjuvanticity of silica is correlated to its effects on one or more of the various functions carried out by macrophages on immune responses.

Susceptibility of inbred mice to rickettsiae of the spotted fever group

Abstract: A mouse strain susceptible to lethal infection with Rickettsia conorii was required for testing vaccine efficacy and for studying the immunology and pathogenesis of infection. Among 20 strains of inbred mice inoculated intraperitoneally with the Malish strain of R. conorii, the C3H/HeJ mouse strain was the most susceptible, with a 50% lethal dose of approximately 10 PFU. Infection of all mouse strains resulted in a measurable antibody response; the highest titers correlated with the greatest degree of rickettsial replication as measured by plaque assay of infected spleen homogenates. Inoculation of C3H/HeJ mice with 5.0 log10 organisms of strain Malish by the subcutaneous route did not result in lethal infection. The Casablanca and Moroccan strains of R. conorii were not lethal for C3H/HeJ mice and, in addition, produced plaques in L-929 cells morphologically distinct from those produced by the Malish strain. The only other spotted fever group rickettsia tested which produced a lethal infection in C3H/HeJ mice was Rickettsia sibirica. Sublethal infection with any of the spotted fever rickettsiae tested protected against lethal infection with R. conorii. These data established a lethal challenge system for examining the protective efficacy of spotted fever immunogens and presented evidence of biological variation among strains of R. conorii.

High resolution banding analysis of the involvement of strain balb/c- and akr-derived chromosomes no. 15 In plasmacytoma-specific

Abstract: Plasmacytomas were induced in (BALB/c X AKR 6;15) X BALB/c backcross mice where one of the BALB/c-derived chromosomes No. 15 was replaced by the AKR(6;15)-derived Robertsonian 6;15 chromosome. (BALB/c X AKR 6;15)F2 mice that were homozygous for Rb 6;15 were mated to BALB/c mice. Plasmacytomas were induced in the progeny by intraperitoneal injection of pristane. The cytogenetic marker permitted the distinctive identification of the two chromosome 15 homologues, including the distal segment involved in the plasmacytoma-specific translocations. 7 of the 10 plasmacytomas contained the typical t(12;15) translocation. The BALB/c-derived 15 chromosome served as the donor of the translocated segment in six of them. In the seventh, the Rb 6;15 chromosome of the AKR strain was the donor. The remaining three tumors contained the same type of intrachromosomal rearrangement. It arose by the pericentric inversion of the Rb 6;15 chromosome, leading to a variant plasmacytoma-associated rcpt (6;15) translocation. Unlike the usual 6;15 variant that arises by a reciprocal exchange between two separate chromosomes, it was generated by an exchange of the distal segments of a single chromosomal element. High resolution banding analysis of the tumors showed that all translocated breakpoints on chromosomes 15, 12, and 6 were identical with the previously described breakpoints characteristic for the typical 12;15 and the variant 6;15 translocation in murine plasmacytomas. It is known that the distal segment of chromosome 15 carries the c-myc oncogene (23). The PC- associated translocations cut across the 5'-exon of c-myc in the majority of the cases (24,26). The severed oncogene is transposed to the Ig-region on the recipient chromosome. Since the BALB/c strain is highly sensitive to PC-induction, we were interested to examine the question whether its chromosome 15 is preferred as the oncogene donor in AKR X BALB/c backcross mice that carry cytogenetically distinguishable 15 chromosomes. Our results show that this is not the case, since the same segment of the AKR-derived chromosome 15 could also serve in the same capacity. This is in contrast with T cell leukemogenesis where we have previously found that the trisomization- associated duplication of chromosome 15 occurred in a highly asymmetrical fashion, depending on the donor strain of No. 15 (9-11).

High resolution banding analysis of the involvement of strain BALB/c- and AKR-derived chromosomes No. 15 in plasmacytoma-specific translocations.

Abstract: Plasmacytomas were induced in (BALB/c X AKR 6;15) X BALB/c backcross mice where one of the BALB/c-derived chromosomes No. 15 was replaced by the AKR(6;15)-derived Robertsonian 6;15 chromosome. (BALB/c X AKR 6;15)F2 mice that were homozygous for Rb 6;15 were mated to BALB/c mice. Plasmacytomas were induced in the progeny by intraperitoneal injection of pristane. The cytogenetic marker permitted the distinctive identification of the two chromosome 15 homologues, including the distal segment involved in the plasmacytoma-specific translocations. 7 of the 10 plasmacytomas contained the typical t(12;15) translocation. The BALB/c-derived 15 chromosome served as the donor of the translocated segment in six of them. In the seventh, the Rb 6;15 chromosome of the AKR strain was the donor. The remaining three tumors contained the same type of intrachromosomal rearrangement. It arose by the pericentric inversion of the Rb 6;15 chromosome, leading to a variant plasmacytoma-associated rcpt (6;15) translocation. Unlike the usual 6;15 variant that arises by a reciprocal exchange between two separate chromosomes, it was generated by an exchange of the distal segments of a single chromosomal element. High resolution banding analysis of the tumors showed that all translocated breakpoints on chromosomes 15, 12, and 6 were identical with the previously described breakpoints characteristic for the typical 12;15 and the variant 6;15 translocation in murine plasmacytomas. It is known that the distal segment of chromosome 15 carries the c-myc oncogene (23). The PC-associated translocations cut across the 5'-exon of c-myc in the majority of the cases (24,26). The severed oncogene is transposed to the Ig-region on the recipient chromosome. Since the BALB/c strain is highly sensitive to PC-induction, we were interested to examine the question whether its chromosome 15 is preferred as the oncogene donor in AKR X BALB/c backcross mice that carry cytogenetically distinguishable 15 chromosomes. Our results show that this is not the case, since the same segment of the AKR-derived chromosome 15 could also serve in the same capacity. This is in contrast with T cell leukemogenesis where we have previously found that the trisomization-associated duplication of chromosome 15 occurred in a highly asymmetrical fashion, depending on the donor strain of No. 15 (9-11).

Effect of MuLV-related genes on plasmacytomagenesis in BALB/c mice.

Abstract: The role of spreading somatic cell infections with ecotropic MuLV viruses in the induction of plasmacytomas in BALB/cAN pi mice was determined by constructing congenic mice that lacked the gene locus Cv that codes for ecotropic virus. DBA/2 mice that lack Cv on chromosome (chr) 5 carry a closely linked gene Rmcfr that determines resistance to infection with mink cell focus-forming viruses (MCF). Rmcfr was retrogressively back-crossed onto BALB/c for six successive generations to produce N6 mice. N6 mice were mated to each other to produce BALB/c.DBA/2 Rmvfr/Rmcfr homozygotes. This stock of mice lacked Cv, as demonstrated by DNA hybridization and were as fully susceptible to developing plasmacytomas as the parental BALB/c. A second congenic stock BALB/c.DBA/2 Rmcfr/Rmcfr Fv-1n/Fv-1n was also developed, but the mice of this stock showed a reduced incidence of plasmacytomas, as did BALB/c.DBA/2 Fv-1n/Fv-1n mice. These findings indicated Fv-1 or a gene closely linked to it conferred partial resistance to plasmacytomagenesis. In constructing the BALB/c.DBA/2 Fv-1n/Fv-1n stock, a "control" congenic BALB/c.DBA/2 Fv-1b/Fv-1b was also developed at N6. Surprisingly, this stock carried the Qa2+ trait. These mice were also partially resistant to plasmacytomagenesis, suggesting a gene on chromosome 17 (the location of Qa2) or a gene located elsewhere that regulates Qa2 expression is linked to a gene controlling partial resistance to plasmacytoma development.

Vaccination of BALB/c mice against Brugia malayi and B. pahangi with larvae attenuated by gamma irradiation.

Abstract: The vaccination with radiation-attenuated infective larvae of Brugia malayi and B. pahangi was attempted and evaluated in BALB/c mice. Two weeks after intraperitoneal infection with 100 3rd stage larvae, the worms of both species of Brugia were recovered in the peritoneal cavity of BALB/c mice. The average recovery was more than 20% in both Brugia infections. Groups of 10 mice were vaccinated subsequently three times with 100 3rd stage larvae of B. malayi or B. pahangi attenuated by 20 krad gamma irradiation and challenged with the homologous species. Vaccinated mice showed a 95.5% reduction in recovered worms in the challenge infection with B. malayi as compared to the infection in non-vaccinated controls, and a 93.8% reduction in the B. pahangi group.

High-metastatic clones selected in vitro from a recent spontaneous BALB/c mammary adenocarcinoma cell line.

Abstract: The metastatic TS/A line has been recently derived from a spontaneous BALB/c mammary tumor. When TS/A cells were cultured in 0·33 per cent agar, two morphologically distinct types of colonies were observed from which two sets of clones were obtained. E clones were derived from small, transparent colonies, whereas F clones were from large, thick, actively growing colonies. All the clones were tumorigenic in syngeneic BALB/c females. However, E clones showed higher ability than F clones to metastasize spontaneously to the lung. Comparison between E and F clones shows that the high level of spontaneous metastasization to the lung is associated with epithelial-likein vitro growth pattern, spontaneous dome formation and growth pattern in 0·33 per cent agar cultures. The ability to give rise to lung colonies following intravenous inoculation is not a predictive parameter for the spontaneous metastatic potential.

Complete heavy and light chain variable region sequence of anti-arsonate monoclonal antibodies from BALB/c and A/J mice sharing the 36-60 idiotype are highly homologous.

Abstract: Structural and serologic studies on murine A/J monoclonal anti-arsonate antibodies resulted in the identification of a second idiotype family (Id36-60) in addition to the predominant idiotype family (IdCR). Id36-60, unlike IdCR, is a dominant idiotype in the BALB/c strain but is a "minor" idiotype in the A/J strain. The complete heavy and light chain variable region (VH and VL) amino acid sequences of a representative Id36-60 hybridoma protein from both the A/J and BALB/c strains have been determined. There are only four amino acid sequence differences between the VH of antibody 36-60 (A/J) and antibody 1210.7 (BALB/c). Two of these differences arise from single nucleotide changes in which the A/J and BALB/c Id36-60 VH germline gene sequences differ. The two other differences are the result of somatic mutation in hybridoma protein 36-60. In addition, Id36-60 heavy chains employ the same D and JH3 segments in both strains. The entire Vk2 VL of 36-60 and 1210.7 differ by only two amino acids, suggesting that like the heavy chains, they are derived from highly homologous VL genes. The same Jk segment is used in both antibodies. A comparison of the amino acid sequence data from Id36-60-bearing hybridomas suggests that a heavy chain amino acid difference accounts for the diminished arsonate binding by the 1210.7 hybridoma protein. Because the 1210.7 heavy chain is the unmutated product of the BALB/c VH gene, somatic mutation in VH may be required to enhance Ars affinity in this system.

Regulatory effects of isologous anti‐idiotypic antibodies on the formation of different immunoglobulin classes in the immune response to phosphorylcholine in BALB/c mice

Abstract: BALB/c mice were immunized with purified phosphorylcholine (PC)-specific myeloma protein of the TEPC-15 tumor, which bears the major idiotype of the anti-PC response (T15 Id) in this mouse strain. Four months after establishing the anti-idiotypic response, animals were immunized with PC-keyhole limpet hemocyanin under conditions which normally lead to IgE antibody formation. The expression of anti-PC antibodies of each immunoglobulin class was compared to a group of matched control mice not immunized with T15. In BALB/c mice producing anti-idiotypic antibodies the formation of anti-PC IgM, IgG1, IgG2, IgG3 and IgE was suppressed to various extents and for different lengths of time. An exception to this observation was the formation of anti-PC IgA antibodies, in that no significant difference was measured between the two groups of mice. BALB/c mice immunized in the same way with the PC-specific myeloma proteins of the MOPC-167, MOPC-511 and MOPC-603 tumors produced normal levels of anti-PC IgE and IgG antibodies. These results suggest that T15 idiotype-positive antibodies are probably formed within all classes of specific antibodies expressed during an immune response to PC. The possibility of extending the phenomena of anti-idiotype-induced suppression to the level of various classes of specific antibodies, including IgE, might be of interest in the treatment of some allergic diseases.

Epidermal benzo[a]pyrene metabolism and DNA-binding in Balb/C mice: Inhibition by ellagic acid

Abstract: 1. Topical application of ellagic acid, a common plant phenol, to control or to 3-methylcholanthrene (3-MC) pretreated Balb/C mice, resulted in significant inhibition of hepatic and epidermal microsomal aryl hydrogen hydroxylase activity, and of benzo[a]pyrene (BP) binding to epidermal and hepatic DNA in vivo.2. In vitro addition of ellagic acid (0·25 mM) to epidermal microsomal incubation systems from either control or 3-MC-treated animals resulted in 62–75% inhibition of BP binding to calf thymus DNA.3. These studies suggest that ellagic acid could prove useful in understanding and/or modulating polyaromatic hydrocarbon carcinogenesis.

Passive transfer of protective immunity against Brugia malayi in BALB/c mice.

Abstract: To analyse the mechanisms of resistance against infective larvae of Brugia malay induced by 3 times' vaccination with 100 irradiated larvae, passive transfer of protective immunity by serum and/or spleen cells from vaccinated BALB/c mice to normal mice was examined. Resistance was observed by the worm recovery in the peritoneal cavity of mice 2 weeks after intraperitoneal challenge infection with 100 infective larvae. No larva was recovered in the recipients of 1.5 X 10(8) spleen cells from vaccinated mice, whereas an average 25.89% of larvae were found alive in control mice transferred with the same number of spleen cells from age-matched non-vaccinated donors. However, passive transfer of either 0.1 or 1.0 ml immune serum failed to protect the recipient mice against the challenge infection. Furthermore, increased larval recovery was induced by challenge infection with larvae which were previously incubated in 10% immune serum. The results suggest that an antibody-dependent immunological enhancement may occur in these experiments.

Passive adoptive immunotherapy of low-immunogenic BALB/c lymphoma by syngeneic alloimmune T lymphocytes

Abstract: The virus-induced BALB/c lymphoma YC8 is known to be lysed in vitro by syngeneic lymphoid cells immune to non-H-2 antigens of B10.D2 and DBA/2 backgrounds. This tumor is weakly immunogenic in vivo and kills 100% of syngeneic mice with 1 × 103 cells given either intravenously (i.v.) or intraperitoneally (i.p.). We show here that i.v.-injected YC8 cells grow preferentially in the liver, where colonies become microscopically visible after 7-10 days, and, less frequently, in the kidneys and spleen but not in the lung. Passive adoptive immunotherapy of this tumor was carried out with alloimmune BALB/c anti-B10.A, anti-pool (donors were immunized with lymphocytes from 5 different strains), anti-A and anti-DBA/2 splenic and lymph node cells. When administered i.p. 1, 3 or 5 days after tumor cells had been given i.p. and with a schedule of 5 subsequent daily inocula, anti-DBA/2 lymphocytes cured 100%, 80% and 60% of animals respectively. A weaker effect was obtained with anti-pool immune cells whereas anti-B10.A and anti-A lymphoid cells had not therapeutic effects. When given i.v., the anti-DBA/2 immune lymphocytes were able to cure both i.v. and i.p. tumor-injected mice. A significant effect was observed also when the onset of immunotherapy was delayed until 7 or 10 days after tumor injection. By depleting the BALB/c anti-DBA/2 immune cells with appropriate monoclonal antibodies and complement, it was found that Lyt 1 + 2- cells played the major role in eradicating the neoplasm. in vitro phenotypic and functional analysis showed that the immune cell population included 70% of Thy 1 +, 38% of Lyt 1 + and 18-20% of Lyt 2+ cells. Immune lymphocytes were not cytotoxic in vitro to YC8 or DBA/2 targets whereas they proliferated after restimulation with DBA/2 but only weakly with YC8 cells. This shows that it is possible to cure mice bearing a disseminated lymphoma which expresses non-immunogenic antigens recognized by BALB/c anti-DBA/2 immune T lymphocytes. These immune lymphocytes had no cytotoxic activity in vitro and their major effector cell subpopulation displayed the Thy 1+, Lyt 1+ phenotype.

A developmental genetic analysis of locomotor activity in mice: maternal effects in the BALB/c and C57BL/6 strains and heredity in F1 hybrids

Abstract: Continuous recording of locomotor activity of mice during 48 h in seminatural enclosures was performed at 21 and 75 days of age, on the same individuals. Four groups of inbred subjects were compared for amount of locomotor activity and its daily distribution: in both BALB/C ( = BALB) and C57BL/6 ( = C57) strains, pups were either fostered by a mother of their own strain or crossfostered to a mother of the other. In addition, two reciprocal F1's were compared to the parental strains. While no significant effect of crossfostering to a C57 dam appeared in BALB mice, 21-day-old C57 crossfostered to a BALB dam were more active and more nocturnal than those reared by a C57 dam. In C57 mice the change in activity level between 21 and 75 days was also affected by crossfostering. Reciprocal F1 hybrids did not differ. A BALB pattern was dominant at 21 days for amount of activity and for change between 21 and 75 days. For daily distribution of activity, F1 hybrids were BALB-like at weaning and C57-like (with heterosis) in adulthood.

Monoclonal antibody to an alveolar macrophage surface antigen in hamsters.

Abstract: A conventionally produced antibody specific for hamster lung macrophages was prepared by immunizing guinea pigs with lung macrophages from LSH (inbred) hamsters. Specificity was achieved by absorbing the resulting serum with hamster blood cells and peritoneal macrophages. This antibody was used to precipitate antigen from detergent lysates of hamster lung macrophages. To produce monoclonal antibodies, F1 hybrids of Balb C X C57Bl6 mice were immunized with these immunoprecipitates. Fusion of splenic lymphocytes from these mice with NS-1 myeloma cells produced 4 hybrid cell lines. Subcloning yielded 18 lines producing antibody reacting only with lung macrophages, and 2 lines secreting nonreactive antibody. Screening used lung and peritoneal macrophages and an ELISA assay. Using gel electrophoresis and lysates of 125I-labeled lung macrophages, all 18 lines reacted with the same antigen, a protein of 102,000 daltons. Subclasses of these monoclonal antibodies included IgG2b kappa and IgG1 kappa. Quantitative ELISA assays showed that the antibody reacted with lung macrophages of LSH and LVG (outbred) hamsters, but not with hamster resident peritoneal macrophages, spleen cells, or bone marrow cells. The antibody did not cross-react with lung or resident peritoneal macrophages from mice, rats, or guinea pigs. By flow cytometry, no reaction was detected with resident, thioglycollate-elicited, or BCG-stimulated peritoneal macrophages. When frozen sections of lung and other organs were examined by indirect immunofluorescence and immunoperoxidase methods, only alveolar macrophages were stained.