Listeria antigen-binding cells in the spleens of normal and immunized mice resistant or susceptible to listeriosis

Normal mice of the Listeria-resistant C57Bl/6 strain contain in their spleens a higher number of cells that bind Listeria monocytogenes cell wall fraction antigen (LmA) than normal DBA/2 mice, which are more susceptible to infection. LmA-binding cells are probably B cells, nylon-wool adherent, and inhibited by anti-mouse immunoglobulin antibody but not sensitive to the action of monoclonal anti-mouse macrophage and anti-Thy.1.2 antibody. A single intraperitoneal injection of 10(8) Listeria monocytogenes causes a rapid increase in the number of LmA-binding cells in the spleens of C57Bl/6 mice, and this can be seen as early as 24 h. On the other hand, in DBA/2 mice an increase in these cells becomes evident only by the 4th day. Moreover, the increment in the number of LmA-binding cells in C57Bl/6 mice is more marked than in DBA/2 mice.     

Sensitivity of immunocompetent cells of DBA/2 and C57Bl/6 mice to cyclophosphamide

T cells were most sensitive to cyclophosphamide in DBA/2 mice, while in C57Bl/6 mice both T and B cells were sensitive. The formation of antibody-producing cells and the production of specific antibodies were delayed in DBA/2 mice immunized after pretreatment with antitumor drug. Accumulation of antibody-producing cells in the spleen was more active in immunized C57Bl/6 mice treated with cyclophosphamide compared to animals not treated with cyclophosphamide.     

Immunological alterations inducible by mercury compounds. II. HgCl2 and gold sodium thiomalate enhance serum IgE and IgG concentrations in susceptible mouse strains

We determined the levels of total IgE, IgG and IgM in the sera of HgCl2 and gold sodium thiomalate (GST) treated A.SW, C57Bl/6, and DBA/2 mice. In HgCl2 treated A.SW mice, IgE and IgG levels increased up to 30 times above normal. In C57Bl/6 mice HgCl2 induced a slight IgE increase, but no change in IgG. Strain DBA/2, by contrast, did not show significant increases in either IgE or IgG. A.SW mice also proved susceptible to the immunostimulatory effects of GST in that they responded by significant increases in IgE, IgG, and IgM. C57Bl/6 mice responded to GST by an increase in IgM alone, and DBA/2 mice again, were resistant. The same strain-specific responses have been reported with respect to the autoimmunizing effects inducible by HgCl2 and GST.     

Comparative in vivo sister chromatid exchange induction by ethyl carbamate in maternal and fetal tissues of tumor-susceptible and -resistant murine strains

Murine susceptibility to ethyl carbamate-induced carcinogenesis is strain dependent. In vivo sister chromatid exchange (SCE) responses to ethyl carbamate were evaluated in bone marrow cells of gravid adenoma-susceptible (ICR/Jcl), and resistant (C57Bl/6J) and (DBA/2J) murine dams, as well as in liver cells of their respective ICR/Jcl, C57Bl/6J X DBA/2J (BDF1), and DBA/2J X C57Bl/6J (BDF), fetuses following a single intravenous injection of 1.1, 2.2, or 3.3 mmol/kg of ethyl carbamate on gestation day 13/14. Bone marrow tissues of C57Bl/6J and DBA/2J, but not ICR/Jcl dams, demonstrated greater sensitivity to SCE induction than liver cells of their respective fetuses. Furthermore, relative SCE responses in bone marrow among dams indicated greater sensitivity of the more tumor-susceptible ICR/Jcl and C57Bl/6J strains to SCE induction by ethyl carbamate relative to the more tumor-resistant DBA/2J strain. In addition, concurrent alterations (stimulation or inhibition) of bone marrow cell cycle kinetics by ethyl carbamate were consistent with hormone-related, strain-dependent hematopoietic stress during pregnancy.     

Genetics of natural resistance to Sendai virus infection in mice.

The genetics of resistance to a naturally occurring respiratory infection caused by Sendai virus was examined in F1, F2, and backcross progeny of resistant C57BL/6J and susceptible DBA/2J mice and in 25 recombinant inbred strains. An intranasal inoculum of 0.1 50% tissue culture infective dose (low dose) of Sendai virus caused 0% mortality in C57BL/6J and F1 mice and 73% mortality in DBA/2J mice. An inoculum of 1.0 50% tissue culture infective dose (high dose) caused 3, 0, and 89% mortality in C57BL/6J, F1, and DBA/2J mice, respectively. Low-dose infection caused 36% mortality in F1 X DBA/2J hybrids and 0% mortality in F2 hybrids. High-dose infection caused 29 and 32% mortality in F1 X DBA/2J and F2 hybrids, respectively. Resistance was not linked to H-2 haplotype, coat color, or sex. High-dose infection caused deaths in 12 recombinant inbred strains, and the strain distribution pattern was concordant with that of a chromosome 1 marker, Sas-1, in 20 of 25 strains (P less than 0.01). Resistance therefore behaved as a simple Mendelian dominant trait which presumptively mapped to chromosome 1.     

Lack of strain differences in spatial learning among seizure-prone and seizure-resistant mice

Learning rates were examined in the following inbred mice strains: DBA/2, C3H/He, C57Bl/6J, El, and ddY. DBA/2 mice become susceptible to audiogenic seizures after 2–3 weeks of age and El mice have generalized seizures in response to handling after 3 months of age, but the remaining three strains do not develop seizures. In this study, mice from all five strains underwent 32 training trials in a Morris water maze at 7–9 weeks of age. The seizure-prone DBA/2 and El mice, along with the nonepileptic ddY and C57Bl/6J mice, exhibited learning at similar rates, but the nonepileptic C3H/He mice were unable to learn the water maze task, probably due to visual difficulties. In the C57Bl/6J strain only, female mice learned the task significantly faster than males. There was no difference in the learning rate between the El strain and its parent ddY strain, or any correlation between spatial learning ability and kindling rates in these strains.     

Cytomegalovirus hepatitis: characterization of the inflammatory infiltrate in resistant and susceptible mice.

Mice susceptible and resistant to murine cytomegalovirus (MCMV) were infected with this virus and livers were harvested after 2-231 days. Cryostat sections were stained to visualize cells bearing CD4, CD8 or Mac-1 antigens. Mac-1+ cells were prevalent in inflammatory foci after 2 days. These cells persisted in susceptible BALB/c and A/J mice, but disappeared from livers of resistant C57Bl/6 and CBA/CaH mice by day 28. T cell inflammation peaked on days 7-11. This declined by day 56 in C57Bl/6 and CBA/CaH mice, but persisted in BALB/c and A/J mice for at least 231 days. Persistent CD8+ cells were dispersed throughout the parenchyma. More CD8+ cells were observed 7-14 days after infection in the livers of bg/bg (natural killer (NK) cell-deficient) C57Bl/6 and CBA mice, and in C57Bl/6 mice depleted of NK1.1 cells by MoAb. Thus, mice of strains susceptible to MCMV exhibit hepatitis characterized by persistence of dispersed CD8+ cells. This phenomenon may be limited by NK cells in resistant strains.     

The relation between the T cells responsible for cell-mediated cytotoxic killing of mastocytoma cells and the helper-cell effect.

The relationship between T cells involved in cell-mediated immunity and antibody response of C57Bl/6J mice towards DBA/2 mastocytoma cells was investigated. Spleen cells primed with viable mastocytoma cells demonstrated marked cell-mediated cytotoxicity (CMC) in vitro, but antibody response of these cells to a hapten (TNP) conjugated to the allogeneic tumour cells in vitro was suppressed as compared with that of normal spleen cells. In contrast, spleen cells primed with frozen-thawed mastocytoma cells showed no CMC, but antibody response to the hapten in vitro of these cells was enhanced. C57Bl/6J mice primed with frozen-thawed mastocytoma cells produced more cytotoxic antibody than non-primed mice when immunized with viable mastocytoma cells. These results indicate that T cells involved in cell-mediated immunity and those involved in the antibody response to allogeneic mastocytoma cells are distinct.?222     

Immunity Parameters in Mice of Different Strains

Quantitative composition and functional activity of immunocompetent cells differ in mice of different strains. The counts of T cells in the bone marrow and spleen, proliferative activity of T cells in the spleen, levels of IL-2 and IL-10 production by splenic T cells, number of antigen-specific T cells and their functional activity are low in C57Bl/6, BALB/c, and CC57W mice and high in CBA/CaLac, DBA/2, and C3H animals. Low phagocytic activity of peritoneal macrophages was detected in BALB/c and CC57W mice and high activity in C3H animals. The content of antibody-producing cells in the spleens of C57Bl/6, BALB/c, and CC57W mice is higher than in CBA/CaLac, DBA/2, C3H, A/SN, and AKR/JY mice. Functional activity of B cells is lower in BALB/c and CC57W compared to CBA/CaLac and DBA/2 mice. __________ Translated from Byulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 140, No. 8, pp. 189–191, August, 2005     

Characteristics of cell mediating spontaneous resistance to bone marrow allografts

Mice of most strains show a genetically determined ability to reject foreign bone marrow grafts even after lethal irradiation. The effector cells mediating this resistance are spleen localised, lymphoid in morphology, and rapidly renewing. Two additional aspects of these cells were characterized in the present study, i.e., their sensitivity to: 1) anti-T cell and -B cell antibodies, and 2) the immunoregulator PGE2. T and B cell depleted splenocytes, or splenocytes from PGE2 pre-treated, highly resistant mice (C57Bl/6J) were transferred into irradiated, non-resistant secondary host mice (129/J) to establish whether or not they would retain their normally strong ability to spontaneously reject a third party (DBA/2) bone marrow allograft. In all cases, bone marrow seeding was assayed by enumerating the spleen colonies present in the secondary host 7 days after bone marrow grafting. Irradiated 129/J mice injected with low numbers (20 x 10(6) of untreated C57Bl/6J spleen cells prior to DBA/2 bone marrow contained 27.8 +/- 1.9 colonies/spleen, while mice injected with the same number of T and B depleted C57Bl/6J spleen cells contained significantly fewer (16.3 +/- 1.7) colonies/spleen. On the other hand, when C57Bl/6J spleen cells were incubated overnight with PGE2 prior to injection (20 x 10(6) into the 129/J hosts, they were unable to prevent the development of numerous colonies upon challenge with the DBA/2 bone marrow allograft (31.5 +/- 1.5 colonies/spleen: PGE2 pre-treated vs 16.9 +/- 2.1 colonies/spleen: non-pre-treated, control). The results demonstrate firstly, that spleen cells depleted of both Thy-1- and Ig-bearing cells appear to have concentrated for the effector cells responsible for bone marrow allograft rejection, and secondly, such effector cells could be suppressed by short-term exposure to PGE2, resulting in successful "take" of the bone marrow allograft.     

IL-21R expression on CD8+ T cells promotes CD8+ T cell activation in coxsackievirus B3 induced myocarditis

IL-21 is a multi-functional cytokine which can promote survival, proliferation and activation of T and B lymphocytes including CD8 T cells. Previous studies have shown that autoimmune CD8+ T cells are the primary pathogenic effector cell in coxsackievirus B3 (CVB3) induced myocarditis in C57Bl/6 mice. To evaluate the role of IL-21 in promoting CD8+ T cell mediated cardiac injury in myocarditis, C57Bl/6 and IL-21RKO mice were infected with CVB3. IL-21RKO mice developed significantly less myocarditis than C57Bl/6 animals although cardiac virus titers were equivalent between the mouse strains. Numbers of CD8+IFNγ+ cells were decreased in IL-21RKO mice but numbers of either CD4+IFNγ+ or CD4+IL-4+ cells were not significantly different from C57Bl/6 animals indicating a selective effect of IL-21 signaling on the CD8+ T cell response. To confirm that IL-21 signaling exclusively functions at the level of the CD8+ T cell in CVB3 induced myocarditis, purified CD8+ cells were isolated from either C57Bl/6 or IL-21RKO donors and adoptively transferred into CD8KO recipients prior to CVB3 infection. CD8KO recipients given either C57Bl/6 or IL-21RKO CD8+ cells showed equivalent reconstitution of the CD8+ cells in the spleen but the recipients given C57Bl/6 CD8+ cells showed significantly greater myocarditis than recipients of IL-21RKO CD8+ cells. These data demonstrate that IL-21 signaling directly in the CD8+ cell population is required for CVB3-induced myocarditis.     

Ectromelia virus replication in major target organs of innately resistant and susceptible mice after intravenous infection

Summary The kinetics of ectromelia virus replication in the spleen and liver and of / interferon production in the spleen were determined during the first 3 days after intravenous infection with the virulent Moscow strain in resistant C57 BL/6 and susceptible DBA/2 mice. Virus replication in the spleen as measured by assays for virus DNA and infectious centers was suppressed in C57 BL/6 mice relative to DBA/2 mice within the first 1 or 2 days of infection. Infectious centers increased in DBA/2 mice but not in C57 BL/6 mice. Differences in virus replication between strains were less discrete when spleens were assayed for infectious virus than when they were assayed for infectious centers because infectious centers of most C57 BL/6 mice had more infectious virus than infectious centers of DBA/2 mice. Virus replication in the liver, the major target organ, as measured by virus DNA and infectious virus assays, was suppressed in C57 BL/6 mice relative to DBA/2 mice 3 days after infection but not before that interval. The results indicate that genetic control of ectromelia virus replication begins within the first 1 or 2 days of infection in the spleen but is delayed in the liver and that genetic control is directed at the prevention of virus spread more than at virus replication.     

Genetic determinants of lung virus titers and resistance to lethal Sendai virus pneumonia

Summary C 57 BL/6J mice are resistant to lethal Sendai virus pneumonia and have lower lung virus titers than susceptible DBA/2J mice. Linkage between these phenotypes was tested indirectly in segregant hybrids.Sas-1,B2m, andb on chromosomes 1, 2, and 4 were linked to significant (P<.05) differences in virus-induced mortality;d on chromosome 9 was associated with a similar but smaller difference (.1>P>.05). Mean lung virus titers were higher in F₁ × DBA/2 J mice that were homozygous for DBA alleles atB2m, b, andd than in heterozygotes. The difference in lung virus titers was larger between mice that were dihomozygous/diheterozygous for paired combinations;B2m-d (P<.02),B2m-b (P<.06), andb–d (P<.05) and largest between mice that were trihomozygous/triheterozygous forB2m-b–d (P<.001). The distribution of virus titers among 22 recombinant inbred strains derived from C 57 BL/6 J and DBA/2 J progenitors indicated 1) that the loci linked toB2m, b, andd are among at least 4 loci that regulate lung virus titers, 2) thatSas-1 may be linked to a fourth locus, 3) that the C 57 BL/6 J genome contains at least one susceptibility locus, possibly within H-2, and 4) that some of these loci may be expressed through natural killer cell activity.     

Adjuvant activity of mycobacterial fractions: adjuvant activity of synthetic N-acetylmuramyl-dipeptide and the related compounds.

Immunological activity of synthetic cell wall peptidoglycan subunits was examined in guinea pigs and mice. It was concluded that the minimal adjuvant-active subunit of cell wall peptidoglycan for the induction of delayed-type hypersensitivity to monoazobenzenearsonate-N-acetyl-L-tyrosine and for circulating-antibody formation to bacterial alpha-amylase and the thymus-independent antigen DNP-Ficoll was N-acetylmuramyldipeptide, MurNAc-L-Ala-D-isoGln. N-acetylmuramyldipeptide and 6-O-stearoyl-N-acetylmuramyldipeptide showed no adjuvant activity in the generation of cell-mediated cytotoxic effector cells in the spleens of C57Bl/6J mice after in vivo immunization with the allogeneic antigen mastocytoma P815-X2 cells, but N-acetylmuramyldipeptide showed adjuvant activity after in vitro sensitization of C57Bl/6J mouse spleen cells to the alloantigen mitomycin C-treated DBA/2 mouse spleen cells. It was also shown that 6-O-stearoylation of N-acetylmuramylpeptide could not potentiate the adjuvant activity of N-acetylmuramyldipeptide. Mitogenic and antitumor activities were not observed in either N-acetylmuramyldipeptide or 6-O-stearoyl-N-acetylmuramyldipeptide in mouse systems.     

Immune reactions in different mouse strains

The responses of immunocompetent cells to thymus-dependent antigen differ in mice of different strains. Immunization stimulated phagocytic activity of peritoneal macrophages in CBA/CaLac, DBA/2, and BALB/c mice and suppressed it in CC57W mice. By the formation of antibody-producing cells in the spleen in response to thymus-dependent antigen DBA/2 and CBA/CaLac mice can be classified as high responders, BALB/c mice as medium-responders, and C57Bl/6 and CC57W mice as low responders.     

The potentiality of antibody-producing cells. I Bispecific cell occurrence in double stimulated cultures of syngeneic or allogeneic spleen cells of the mouse.

Cultures of spleen cells from Swiss, C57Bl or DBA/2 mice stimulated with 2,4,6-trinitrophenyl (TNP) conjugated sheep erythrocytes (SRBC) were used for studying the in vitro responses to TNP and native SRBC antigens and the frequency of occurrence of cells responding to both antigens. The response was revealed by plating the cultured cells with both native SRBC and TNP-conjugated pigeon erythrocytes (TNP--PRBC). Specific responses were obtained in all the cultures. Bispecific haemolytic plaque-forming cells (PFC) were detected in almost all cultures of individual Swiss mice cells with a frequency of 2-5--14 PFC/10(6) cells recovered. In DBA/2 cell cultures bispecific PFC were found in half the cultures (2-5--8-3/10(6) cells) and in C57Bl cell cultures in 30 per cent of the cultures (7--21/10(6) cells). When cells from individual Swiss mice immunized in vivo with TNP--SRBC were as an allogeneic culture from the 2nd day after immunization in the presence of TNP--SRBC, the frequency of bispecific PFC increased from 8 to 30/10(6) cells. Mixed allogeneic cultures of normal C57Bl and DBA/2 cells yielded high specific responses with regular occurrence of bispecific PFC only when the numbers of cells cultured together was small. However, when allogeneic cells were mixed 24 hours after starting the cultures, all responses were stimulated and bispecific PFC were found in considerable numbers (4--33/10(6) cells). Cross-reactivity between TNP--PRBC and native SRBC antigens was studied by culturing cells with each of the antigens and plating the cells with both, or by immunizing in vivo with SRBC or PRBC and culturing the cells with both antigens from the 2nd to the 5th day after immunization with both antigens. In no instance did bispecific PFC exceed background levels (0-1--0-6/10(6) cells) in these control experiments.     

Increase in Slow Afterhyperpolarization Led to Learning Delay in DBA mice

We showed that differences in learning capacity between DBA and C57Bl/6 mice correlates with differences in slow afterhyperpolarization amplitude in hippocampal CA1 pyramid neurons. In DBA mice learning capacity is lower, but the amplitude of slow afterhyperpolarizations higher than in C57Bl/6 mice. __________ Translated from Byulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 140, No. 9, pp. 253–256, September, 2005     

Growth of transplantable melanoma and leukaemia and prevention of virus-induced leukaemia in long lived radiation chimeras constructed with unmanipulated bone marrow.

Haemopoietic radiation chimeras across the H-2 barrier (BALB/c----C57Bl/6; H-2d----H-2b chimeras and vice versa) have been studied for their capacity to suppress the growth, or to reject, transplantable B16 melanotic melanoma and radiation leukaemia virus-induced, transplantable leukaemia. Also, radiation leukaemia virus (RadLV) obtained from the thymus of leukaemic C57Bl/6 mice was injected i.p. into established chimeras (H-2d----H-2b). As expected, long lived, graft versus host disease free allogeneic chimeras constructed with intact bone marrow were unable to reject the tumours both when recipients were BALB/c----C57Bl/6 or C57Bl/6----BALB/c chimeras. However, also inoculation of a large number of immunocompetent cells from normal BALB/c mice into BALB/c----C57Bl/6 chimeras, failed to promote a rejection of the tumours. On the contrary, the same amount of syngeneic (BALB/c) immunocompetent cells prevented growth of melanoma when transferred into athymic nude BALB/c mice, while the tumour grew unimpaired in untreated athymic nude BALB/c mice. The same type of H-2d----H-2b chimeras displayed complete resistance to inculation of leukaemogenic H-2b restricted RadLV while all H-2b----H-2b, syngeneically reconstituted mice developed disseminated leukaemia. These findings demonstrate that: (a) a powerful suppressive principle operates in the chimeras which does not allow effector function and anti-tumour activity of passively transferred normal, mature T cells from resistant BALB/c mice. Thus, no H-2 restriction of donor T cells can be advocated for suppression of anti-tumour effector functions in the chimeras. (b) New donor (BALB/c, H-2d) marrow character in the H-2d----H-2b chimeras prevents expression of the H-2b restricted viral activity and leukaemogenic transformation and/or proliferation.     

The role of macrophage activation and of Bcg-encoded macrophage function(s) in the control of Mycobacterium avium infection in mice.

Following the intraperitoneal inoculation of 2.5 x 10(8) colony-forming units of Mycobacterium avium strain ATCC 25291, there was bacillary growth in the liver, spleen and peritoneal cavity of C57BL/6, C57BL/10, DBA/1 and BALB/c mice whereas DBA/2, C3H/He, CBA/Ca and CD-1 mice controlled the infection showing constant or slightly decreasing numbers of viable bacteria in the liver and spleen and effective clearance of the bacilli from the peritoneal cavities. The acquisition of non-specific resistance (NSR) to Listeria monocytogenes during the infection by M. avium was high in C57BL/6, BALB/c and C3H/He mice and negligible in DBA/2 and CD-1 mice. The magnitude of the acquisition of NSR was reduced in T cell-deficient mice and was directly proportional to the dose of the inoculum of M. avium. The production of hydrogen peroxide by phorbol myristate acetate-stimulated peritoneal macrophages of M. avium-infected mice was higher in C57BL/6 and BALB/c mice than in CD-1, DBA/2 and C3H/He animals. BALB/c. Bcgr (C.D2) mice, unlike their congenic strain BALB/c, restricted bacterial growth following the intravenous inoculation of 2.5 x 10(8) CFU of M. avium as efficiently as DBA/2 mice. C.D2 and BALB/c peritoneal macrophages from infected mice produced similar amounts of H2O2 but BALB/c mice developed higher levels of NSR to listeria than C.D2 mice. The production of nitrite by peritoneal macrophages from infected mice was found to be enhanced in DBA/2 and C3H/He but not in BALB/c, C57BL/6, DC-1 and C.D2 mice. Resident peritoneal macrophages from C.D2 mice were more bacteriostatic in vitro for M. avium than macrophages from BALB/c mice. The same relative differences between the two macrophage populations were observed when the cells were activated with lymphokines. The results show that the populations were observed when the cells were activated with lymphokines. The results show that the resistance to M. avium infection in mice is under the control of the Bcg gene and that susceptibility may be due to some defect in macrophage antibacterial function not completely overcome by the activation of this phagocyte in the susceptible strains of mice.     

Delayed toxicity of cyclophosphamide on the bladder of DBA/2 and C57BL/6 female mouse

The present study describes the delayed development of a severe bladder pathology in a susceptible strain of mice (DBA/2) but not in a resistant strain (C57BL/6) when both were treated with a single 300 mg/kg dose of cyclophosphamide (CY). Inbred DBA/2 and C57BL/6 female mice were injected with CY, and the effect of the drug on the bladder was assessed during 100 days by light microscopy using different staining procedures, and after 30 days by conventional electron microscopy. Early CY toxicity caused a typical haemorrhagic cystitis in both strains that was completely repaired in about 7-10 days. After 30 days of CY injection ulcerous and non-ulcerous forms of chronic cystitis appeared in 86% of DBA/2 mice but only in 4% of C57BL/6 mice. Delayed cystitis was characterized by infiltration and transepithelial passage into the lumen of inflammatory cells and by frequent exfoliation of the urothelium. Mast cells appeared in the connective and muscular layers of the bladder at a much higher number in DBA/2 mice than in C57BL/6 mice or untreated controls. Electron microscopy disclosed the absence of the typical discoidal vesicles normally present in the cytoplasm of surface cells. Instead, numerous abnormal vesicles containing one or several dark granules were observed in the cytoplasm of cells from all the epithelial layers. Delayed cystitis still persisted in DBA/2 mice 100 days after treatment. These results indicate that delayed toxicity of CY in female DBA/2 mice causes a bladder pathology that is not observed in C57BL/6 mice. This pathology resembles interstitial cystitis in humans and could perhaps be used as an animal model for studies on the disease.