PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Mice, Inbred BALB C”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed2004

Codon optimization and mRNA amplification effectively enhances the immunogenicity of the hepatitis C virus nonstructural 3/4A gene.

We have recently shown that the NS3-based genetic immunogens should contain also hepatitis C virus (HCV) nonstructural (NS) 4A to utilize fully the immunogenicity of NS3. The next step was to try to enhance immunogenicity by modifying translation or mRNA synthesis. To enhance translation efficiency, a synthetic NS3/4A-based DNA (coNS3/4A-DNA) vaccine was generated in which the codon usage was optimized (co) for human cells. In a second approach, expression of the wild-type (wt) NS3/4A gene was enhanced by mRNA amplification using the Semliki forest virus (SFV) replicon (wtNS3/4A-SFV). Transient tranfections of human HepG2 cells showed that the coNS3/4A gene gave 11-fold higher levels of NS3 as compared to the wtNS3/4A gene when using the CMV promoter. We have previously shown that the presence of NS4A enhances the expression by SFV. Both codon optimization and mRNA amplification resulted in an improved immunogenicity as evidenced by higher levels of NS3-specific antibodies. This improved immunogenicity also resulted in a more rapid priming of cytotoxic T lymphocytes (CTLs). Since HCV is a noncytolytic virus, the functionality of the primed CTL responses was evaluated by an in vivo challenge with NS3/4A-expressing syngeneic tumor cells. The priming of a tumor protective immunity required an endogenous production of the immunogen and CD8+ CTLs, but was independent of B and CD4+ T cells. This model confirmed the more rapid in vivo activation of an NS3/4A-specific tumor-inhibiting immunity by codon optimization and mRNA amplification. Finally, therapeutic vaccination with the coNS3/4A gene using gene gun 6-12 days after injection of tumors significantly reduced the tumor growth in vivo. Codon optimization and mRNA amplification effectively enhances the overall immunogenicity of NS3/4A. Thus, either, or both, of these approaches should be utilized in an NS3/4A-based HCV genetic vaccine.

Animals↗
PubMed1999

Onset of T-cell receptor Vbeta8.1 and Dbeta2.1 V(D)J recombination during thymus development of inbred mouse strains.

The assembling of T-cell receptor (TCR alpha/beta and gamma/delta) genes depends on the V(D)J recombination occurring in early thymocytes during thymus ontogeny. The V(D)J recombination reaction is directed by a recombinase complex from the RAG-1 and RAG-2 genes, and is modulated by several other gene products. Due to the essential role of the TCRbeta in thymocyte differentiation, it is important to define with precision the temporal emergence of the TCRbeta recombination in normal non-manipulated mouse strains. We analysed the onset of V(D)J recombination between TCRVbeta8.1 and Jbeta2.1 gene segments during fetal development of the thymus in three non-manipulated inbred strains of mice; BALB-c, C57BL/6 and CBA. We show that the emergence of the V(D)J recombination at the TCRbeta locus differs among strains, suggesting an in vivo role of the different genetic backgrounds in driving gene rearrangements.

Animals↗
PubMed2001

Immature thymocytes that fail to express TCRbeta and/or TCRgamma delta proteins die by apoptotic cell death in the CD44(-)CD25(-) (DN4) subset.

Pre-TCR/CD3 signals are essential for survival and maturation of (CD44(-)25(+)) DN3 thymocytes via the (CD44(-)25(-)) DN4 stage to CD4(+)CD8(+) (DP) cells, a process termed beta-selection. The exact developmental stages of apoptosis resulting from lack of pre-TCR/CD3 signals have so far not been determined. Here we analyzed apoptotic cell death in relation to expression of clonotypic TCR polypeptides and to cell cycle status in immature thymocyte subpopulations of wild type (wt) mice and of several strains of mice with compromised pre-TCR/CD3 signaling complexes. In wt mice or pre-TCR/CD3-deficient mice, apoptotic cells could not be detected among DN3 cells but accumulated in a subset of DN4 expressing CD69. Apoptotic CD69(+)DN4 cells were rare in wt mice and were found among DN4 cells that were negative or low for intracellular TCRbeta and negative for TCRgamma delta polypeptide chains. Apoptotic CD69(+)DN4 cells were abundant in pre-TCR/CD3 signaling-deficient mice in which most DN4 cells failed to express clonotypic TCR polypeptides. Survival of DN4 cells, but not maturation of DN3 cells to DN4, was found to depend on the expression of clonotypic TCR polypeptides in the same cell. The results suggest that thymocytes unsuccessful in alpha beta or in gamma delta lineage development die by apoptosis in the DN4 subset.

Animals↗
PubMed1994

Regulation of RAG-1 and CD69 expression in the thymus during positive and negative selection.

Successful interaction of the T cell receptor (TCR) with major histocompatibility complex (MHC) molecules during thymic selection down-regulates the expression of the recombination activating genes (RAG)-1 and -2 in cortical thymocytes and thereby prevents further endogenous TCR alpha-chain gene rearrangements (Borgulya, P., Kishi, H., Uematsu, Y. and von Boehmer, H., Cell. 1992. 69: 529-537; Brändle, D., Müller, C., Rülicke, T., Hengartner, H. and Pircher, H., Proc. Natl. Acad. Sci. USA 1992. 89: 9529-9533). To address the question whether down-regulation of RAG-1 activity represents an irreversible process we have blocked TCR-MHC interactions of thymocytes with thymic stromal cells. Firstly, transgenic (Tg) mice expressing a virus-specific MHC class I (H-2Db)-restricted TCR were injected with anti-Db or anti-CD8 monoclonal antibodies and RAG-1 expression was examined by in situ hybridization on thymus sections. The results show that cortical thymocytes up-regulated RAG-1 expression within 24 h after antibody administration. Secondly, immature thymocytes from TCR Tg mice were released from the thymic microenvironment and cultured in vitro for 14 h in single-cell suspension. The amount of RAG-1 mRNA was increased sixfold in cultured cells when compared to freshly isolated thymocytes. In addition, we show that immature thymocytes from TCR transgenic mice bearing non-selective MHC molecules (H-2d) down-regulated RAG-1 expression after antigen-induced TCR engagement. Cytofluorometric analysis further revealed that surface expression of CD69 on immature thymocytes inversely correlated with RAG-1 expression during positive and negative selection processes.

Animals↗
PubMed2005

CCR4-deficient mice show prolonged graft survival in a chronic cardiac transplant rejection model.

Chronic graft rejection mediated by cellular immune responses still poses a serious clinical problem in transplant surgery. Chemokines coordinate the recruitment of leukocytes in inflammatory and immune responses. Their precise functions in the rejection of allografts are still ill defined. This study investigates the role of chemokine receptor 4 (CCR4) in acute and chronic cardiac allograft rejection in mice. Allogeneic hearts were transplanted into CCR4 deficient (CCR4(-/-)) and control recipients. Reverse transcription-PCR showed transcription of macrophage-derived chemokine and thymus and activation-regulated chemokine, the cognate chemokine ligands of CCR4, within the graft. Compared to wild-type controls, acute allograft rejection in CCR4(-/-) recipients was only slightly prolonged. In contrast, in a gallium nitrate chronic cardiac allograft rejection model, cardiac graft survival was significantly prolonged in CCR4(-/-) recipients. A relative increase in the percentage of graft infiltrating CD8(+) T cells in CCR4(-/-) recipients was observed 30 days after transplantation and was accompanied by a decrease in CD4(+) T cells. Moreover, the percentage of NK1.1(+)CD3(+) graft-infiltrating cells was significantly reduced on day 5 and day 30 post transplantation. These findings indicate that CCR4 is involved in the recruitment of NK1.1(+)CD3(+) cells into cardiac allografts and clearly establish an important and novel role for CCR4 in chronic graft rejection.

Animals↗
PubMed2005

Amelioration of acute graft-versus-host disease by NKG2A engagement on donor T cells.

Acute graft-versus-host disease (aGVHD) remains a major complication of allogeneic bone marrow transplantation, which is caused by donor T cells specific for host alloantigens. In a murine model, we found that donor T cells expressed a natural killer cell inhibitory receptor, CD94/NKG2A, during the course of aGVHD. Administration of an anti-NKG2A mAb markedly inhibited the expansion of donor T cells and ameliorated the aGVHD pathologies. These results suggested that the CD94/NKG2A inhibitory receptor expressed on host-reactive donor T cells can be a novel target for the amelioration of aGVHD.

Acute Disease↗
PubMed2004

Neural precursors express multiple chondroitin sulfate proteoglycans, including the lectican family.

Chondroitin sulfate proteoglycans (CSPGs) abnormally accumulate in cerebrospinal fluid (CSF) of both human neonates with preterm hydrocephalus, and P8 hydrocephalic mice. We hypothesized CSF CSPGs are synthesized by neural precursors, separated from ventricular CSF by ependyma, which is often disrupted in hydrocephalus. Western blotting demonstrates that neural precursors cultured as neurospheres secrete CSPGs (> 30 microg/ml) into their media which appear to be very similar to these CSF CSPGs. Some CSPGs bear the stage-specific embryonic antigen-1 (ssea-1), associated with embryonic/neural stem cells. Neurospheres transcribe many CSPG genes, including the entire aggrecan/lectican family, phosphacan, and tenascin. Phosphacan can be detected in media by Western blotting. Aggrecan can be detected in media after purification using hyaluronic acid affinity chromatography. During differentiation, neurospheres downregulate CSPGs. This is the first report to show that proliferating neural precursors synthesize lecticans, including aggrecan, which are downregulated with differentiation. These observations suggest novel links between CSPGs and CNS precursor biology.

Aggrecans↗
PubMed2005

Rapid emergence of escape mutants following infection with murine cytomegalovirus in immunodeficient mice.

Natural killer (NK) cells play a crucial role in the initial host defense against pathogens such as murine cytomegalovirus (MCMV). They respond rapidly and effectively control pathogen replication while the adaptive immune system is being activated. However, in the absence of an adaptive immune system, an effective initial NK cell response is not sufficient for long-term pathogen control as demonstrated by the late recrudescence of disease and mortality in immunodeficient mice infected with MCMV. In this setting, NK cells suppress the initial infection but exert enough selective pressure to drive the outgrowth of MCMV mutants that escape recognition by NK cells. Herein, we characterize the rapid emergence of escape mutants following infection with a plaque-purified MCMV isolate and demonstrate that these mutant viruses are no longer effectively controlled by NK cells. These findings suggest that late recrudescence of viral infections in certain clinical settings may also be due to viral escape from NK cells or other components of innate immunity.

Adoptive Transfer↗
PubMed2002

Presence of a novel subset of NKT cells bearing an invariant V(alpha)19.1-J(alpha)26 TCR alpha chain.

CD1d-deficient (CD1d-/-) mouse lymphocytes were analyzed to classify the natural killer T (NKT) cells without reactivity to CD1d. The cells bearing a V(alpha)19.1-J(alpha)26 (AV19-AJ33) invariant TCR alpha chain, originally found in the peripheral blood lymphocytes, were demonstrated to be abundant in the NK1.1+ but not NK1.1- T cell population isolated from CD1d-/- mice. Moreover, more than half (11/21) of the hybrid cell lines established from CD1d-/- NKT cells expressed the V(alpha)19.1-J(alpha)26 invariant TCR alpha chain. The expression of the invariant V(alpha)19.1-J(alpha)26 mRNA was absent in beta2-microglobulin-deficient mice. Collectively, the present findings suggest the presence of a second NKT cell repertoire characterized by an invariant TCR alpha chain (V(alpha)19.1-J(alpha)26) that is selected by an MHC class I-like molecule other than CD1d.

Amino Acid Sequence↗
PubMed2005

Complete elucidation of a minimal class I MHC natural killer cell receptor haplotype.

The BALB/c inbred mouse is widely used in models of infectious disease, transplantation, and cancer. The differences in the immune responses of BALB/c compared to C57BL/6 mice are especially valuable for the identification of immune regulation genes. One striking immune variance between these mice is in the function of natural killer (NK) cells, and there is strong evidence implicating differential expression of Ly49 genes. In this study, the complete BALB/c Ly49 gene cluster has been sequenced and found to contain six functional genes and two pseudogenes. Compared to C57BL/6 mice, there is a 200 kb region absent in the BALB/c cluster including a complete lack of Ly49h-related genes, which explains the increased susceptibility of BALB/c to cytomegalovirus infection. In addition, there is no BALB/c Ly49d allele, explaining the inability of BALB/c NK cells to kill certain tumor cells. The Ly49 region has now been sequenced in three different inbred mouse strains, and comparisons indicate that the evolution of each haplotype is not straightforward and has involved large-scale deletions/insertions, gene recombination, and unequal crossing over between divergent haplotypes. This study confirms that relatively small murine class I MHC receptor haplotypes exist, analogous to observations made of human killer cell Ig-like receptor gene haplotypes.

Animals↗
PubMed1998

Signalling through NK1.1 triggers NK cells to die but induces NK T cells to produce interleukin-4.

In vivo inoculation of specific antibody is an accepted protocol for elimination of specific cell populations. Except for anti-CD3 and anti-CD4, it is not known if the depleted cells are eliminated by signalling through the target molecule or through a more non-specific mechanism. C57BL/6 mice were inoculated with anti-natural killer (NK1.1) monoclonal antibody (mAb). Thereafter spleen cells were harvested, stained for both surface and intracellular markers, and analysed by flow cytometry. As early as 2 hr post inoculation, NK cells were signalled to become apoptotic while signalling through the NK1.1 molecule activated NK1.1+ T-cell receptor (TCR)+ (NK T) cells to increase in number, and produce interleukin-4 (IL-4). Anti NK1.1 mAb was less efficient at signalling apoptosis in NK cells when NK T-cell deficient [beta 2-microglobulin beta 2m-deficient] mice were used compared with wild type mice. Efficient apoptotic signalling was restored when beta 2m-deficient mice were reconstituted with NK T cells. NK-specific antibody best signals the apoptotic process in susceptible NK cells when resistant NK T cells are present, activated, and secrete IL-4.

Animals↗
PubMed1994

CD4pos, NK1.1pos T cells promptly produce interleukin 4 in response to in vivo challenge with anti-CD3.

Injection of anti-CD3 antibodies causes prompt expression of interleukin (IL)-4, IL-2, and interferon gamma (IFN-gamma) mRNA among spleen cells. The optimal dose of anti-CD3 for such induction was 1.33 microgram/animal; lymphokine mRNA was first observed at 30 min, peaked at 90 min, and was undetectable (for IL-4) or had declined markedly by 4 h. Cells harvested from spleens of mice injected with anti-CD3 90 min earlier secreted IL-4, IL-2, and IFN-gamma without further stimulation. By contrast, in vitro stimulation with anti-CD3 of spleen cell suspensions or splenic fragments from noninjected donors failed to cause prompt production of IL-4 and, even after 24 h of stimulation, the amount of IL-4 produced in such cells was substantially less than that secreted within 1 h by spleen cell suspensions or splenic fragments from mice injected with anti-CD3 90 min earlier. Production of IL-4 by spleen cells from anti-CD3-injected mice was not inhibited by pretreatment with anti-IL-4 antibody or with IFN-gamma or tumor growth factor beta nor enhanced by treatment with IL-4. By contrast, CTLA-4 immunoglobulin (Ig) treatment clearly diminished IL-4 production in response to in vivo anti-CD3, indicating that cellular interactions involving CD28 (or related molecules) were important in stimulation. Cell sorting analysis indicated that the cells that produced IL-4 in response to in vivo injection of anti-CD3 were highly enriched in CD4pos cells with the phenotype leukocyte cell adhesion molecule-1 (LECAM-1)dull, CD44bright, CD45RBdull, NK1.1pos. Indeed, the small population of CD4pos, NK1.1pos cells had the great majority of the IL-4-producing activity of this population. Injection with Staphylococcal enterotoxin B also caused prompt induction of IL-4 mRNA; the cells that were principally responsible for production also had the phenotype of CD4pos, NK1.1pos. These results suggest that possibility that this rare population of T cells may be capable of secreting IL-4 at the outset of immune responses and thus may act to regulate the pattern of priming of naive T cells, by providing a source of IL-4 to favor the development of T cell helper 2-like IL-4-producing cells.

Animals↗
PubMed1994

Class I dependence of the development of CD4+ CD8- NK1.1+ thymocytes.

A small subset of functionally active CD4+ CD8- thymocytes express the NK1.1 marker, as do most CD4-CD8- NK1.1+ thymocytes. Previous studies have failed to implicate a role for major histocompatibility complex (MHC) or related molecules in the selection of the CD4+ CD8- NK1.1+ subset. We report here that the development of most of these cells is sharply reduced in class I-deficient mice, but not in class II-deficient mice. Hence, some CD4+ T cells are class I dependent and not class II dependent. Unlike conventional T cells, however, the development of NK1.1+ thymocytes in both the CD4+ CD8- and CD4- CD8- subsets is dependent on class I MHC expression by hematopoietic cells and not thymic epithelial cells. We propose that these populations are selected by nonpolymorphic class Ib or CD1 molecules.

Animals↗
PubMed2001

Cytometric and functional analyses of NK and NKT cell deficiencies in NOD mice.

Defects in NK and NKT cell activities have been implicated in the etiology of type 1 (autoimmune) diabetes in NOD mice on the basis of experiments performed using surrogate phenotypes for the identification of these lymphocyte subsets. Here, we have generated a congenic line of NOD mice (NOD.b-Nkrp1(b)) which express the allelic NK1.1 marker, enabling the direct study of NK and NKT cells in NOD mice. Major deficiencies in both populations were identified when NOD.b-Nkrp1(b) mice were compared with C57BL/6 and BALB.B6-Cmv1(r) mice by flow cytometry. The decrease in numbers of peripheral NK cells was associated with an increase in their numbers in the bone marrow, suggesting that a defect in NK cell export may be involved. In contrast, the most severe deficiency of NKT cells found was in the thymus, indicating that defects in thymic production were probably responsible. The deficiencies in NK cell activity in NOD mice could only partly be accounted for by the reduced numbers of NK cells, and fewer NKT cells from NOD mice produced IL-4 following stimulation, suggesting that NK and NKT cells from NOD mice shared functional deficiencies in addition to their numerical deficiencies. Despite the relative lack of IL-4 production by NOD NKT cells, adoptive transfer of alpha beta TCR(+)NK1.1(+) syngeneic NKT cells into 3-week-old NOD recipients successfully prevented the onset of spontaneous diabetes. As both NK and NKT cells play roles in regulating immune responses, we postulate that the synergistic defects reported here contribute to the susceptibility of NOD mice to autoimmune disease.

Animals↗
PubMed1999

CD4+CD25+ cells regulate CD8 cell anergy in neonatal tolerant mice.

BACKGROUND: Injection of neonatal BALB/c mice with semi-allogeneic splenocytes leads to antigen-specific tolerance lasting into adulthood. Tolerant mice accept A/J skin grafts and fail to generate CD8 cytotoxic T lymphocyte (CTL) activity against A/J targets. Anergic CD8 T cells are present in tolerant mice, and CD4 regulatory cells function to maintain CD8 cell anergy. METHODS: Neonatal BALB/c mice were injected with 108 live CAF, splenocytes, and mice were deemed tolerant by accepting A/J grafts over 40 days. CD8 cell proliferation was measured by in vitro incorporation of bromodeoxyuridine coupled with fluorescence-activated cell sorter analysis. Alloantigen-specific cytotoxicity was tested using 51Cr release assays of A/J or third-party targets. RESULTS: We demonstrate that A/J-specific anergic CD8 cells are present in neonatal primed mice that develop tolerance but not in neonatal primed mice that reject A/J skin grafts. Anergic CD8 cells show decreased proliferation and no CTL activity against A/J targets. Addition of interleukin-2 (IL-2) to unfractionated cultures fails to restore CTL activity against A/J targets. However, addition of IL-2 to CD4-depleted cultures restores A/J-specific CD8 CTL activity. Removal of CD4+/CD25+ cells, but not CD4+/CD25- cells, also restores CD8 CTL activity against A/J in the presence, but not the absence, of IL-2. Moreover, when added back into cultures, purified CD4+/CD25+ cells from tolerant mice inhibit the generation of CD8 CTL against A/J targets. CONCLUSION: These data indicate that CD8 anergy is associated with the state of tolerance, and that CD4+CD25+ cells from tolerant mice function to maintain A/J-specific CD8 cell anergy in vitro.

Animals↗
PubMed1995

Hepatitis C virus core region: helper T cell epitopes recognized by BALB/c and C57BL/6 mice.

In this study, we characterized the B cell and T cell responses to the hydrophilic portion of hepatitis C virus (HCV) core protein in two strains of mice and identified the respective antigen determinants. BALB/c (H-2d) and C57BL/6 (B6:H-2b) mice were immunized by a subcutaneous injection of recombinant HCV core protein together with Freund's complete adjuvant. The level of antibody production, as determined by ELISA, was consistently higher in BALB/c than in B6 mice. However, antibodies in sera from each strain bound to the N-terminal region of the core protein within amino acids 1 to 28 (MSTNPKPQRKIKRNTNRRPQDVKFPGGG), according to an experiment using non-overlapping peptides that covered the hydrophilic portion of HCV core protein. The T cell responses were also higher in BALB/c than in B6 mice with respect to the proliferative responses of the draining lymph node cells in vitro. By limiting dilution cultures of the draining lymph node cells in vitro repetitively stimulated with recombinant core protein, T cell clones were established from both strains of mice and characterized. The surface markers of these clones were Thy-1.2+, CD3+, TCR alpha beta+, CD4+ and CD8+. The proliferative responses were inhibited in the presence of anti-CD4 or anti-MHC class II monoclonal antibodies. The T cell lines in BALB/c mice recognized an epitope in HCV core at amino acids 72 to 91 (EGRAWAQPGYPWPLYGNEGL). The T cell lines in B6 mice recognized an epitope at amino acids 55 to 74 (RPQPRGRRQPIPKARQPEGR). Thus, mice with different MHC haplotypes recognized different non-overlapping T cell antigenic determinants of HCV core proteins.

Amino Acid Sequence↗
PubMed2005

Natural killer T cells are required for the development of a superantigen-driven T helper type 2 immune response in mice.

We show, here, that one single injection or weekly injections of staphylococcal enterotoxin B (SEB), starting in 1-day-old newborn mice, induced a powerful immune response with a T helper type 2 (Th2) pattern, as judged by the isotype and cytokine profile, with the production of large amounts of SEB-specific immunoglobulin G1 (IgG1), detectable levels of SEB-specific IgE and increased production of interleukin-4 by spleen cells. These protocols also induced an increase in the levels of total IgE in the serum. Memory of SEB was transferred to secondary recipients by using total spleen cells from primed animals. The secondary humoral response in transferred mice was diminished if spleen cells from SEB-treated mice were previously depleted of CD3+ or Vbeta8+ T cells or NK1.1+ cells. In vivo depletion of NK1.1+ cells in adult mice resulted in a marked reduction in the SEB-specific antibody response in both the primary and secondary immune responses. Additionally, purified NK1.1+ T cells were able to perform SEB-specific helper B-cell actions in vitro and in vivo. These results suggest that NK1.1+ T cells are required for the full development of humoral immunological memory, whilst making neonatal tolerance to SEB unachievable.

Adoptive Transfer↗