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C L Sidman

Publications and source records attributed to C L Sidman.

At least 37 records · Page 2Linked to original sources
PubMed1993

Single and combined humoral and cell-mediated immunotherapy of Pneumocystis carinii pneumonia in immunodeficient scid mice.

Homozygous mutant scid/scid (severe combined immunodeficiency) mice (referred to as scid mice) lack both specific humoral and cell-mediated immune functions and are exemplary in vivo models for analysis of host-parasite relationships. In our colony, scid mice routinely and predictably develop spontaneous Pneumocystis carinii pneumonia (PCP) with high morbidity. Previous studies have identified both T cells (specifically, CD4+ cells) and antibody as independent mechanisms of effective anti-P. carinii resistance; however, CD4+ T cells also cause an often fatal hyperinflammatory reaction. The current study has explored the optimal application of these immune components for conferring protection against P. carinii. Anti-P. carinii hyperimmune serum was highly effective at reducing the number of P. carinii organisms in early, intermediate, and advanced stages of PCP and was capable of increasing the mean life expectancy of P. carinii-infected scid mice by more than threefold if provided on a continuing basis. When a short course of hyperimmune-serum therapy was provided prior to transfer of P. carinii-sensitized normal lymphocytes, scid mice were rendered permanently free of P. carinii without the pathological sequelae of the hyperinflammatory reaction. These findings are discussed in the contexts of mechanism and clinical relevance.

Age Factors↗
PubMed1993

Cell populations during tumorigenesis in Eu-myc transgenic mice.

Transgenic mice bearing a c-myc oncogene under control of the immunoglobulin heavy chain (Igh) enhancer (Eu-myc mice) (1, reviewed in 2) undergo a reproducible series of developmental stages and die from malignancies of the B lymphocyte lineage. To investigate the cellular events underlying tumorigenesis in this model, we quantified B lymphoid subpopulations and turnover at various stages of this process. An early stage was characterized by the presence in the blood of many large proliferating B lineage cells marked by surface antigen phenotype IgM+l-, B220low, CD5-, Mac-1low. During a prolonged intermediate 'remission' phase of different duration in each mouse, B lymphocytes in the periphery were non-proliferative, few, and of conventional phenotype (IgM+, B220+, CD5-, Mac-1-), while subsets of precursor B cells were both numerous and highly proliferative in the bone marrow. In the final stage of tumorigenesis, large proliferating cells similar in phenotype to those of the early period reappeared and increased rapidly in numbers. This B cell tumorigenic progression occurred independently of interactions with T lymphocytes. Evidence of massive cell death in the bone marrow during the intermediate phase, plus molecular characterization of the final tumors, suggested that the end of the peripheral 'remission' period and entry into the terminal stage of tumorigenesis may be due to a clone of cells acquiring the ability to circumvent normal processes of cell death and elimination that usually regulate the egress of B cells from the bone marrow to the periphery.

Age Factors↗
PubMed1992

Transgenic T cell receptor interactions in the lymphoproliferative and autoimmune syndromes of lpr and gld mutant mice.

To investigate the role of T cell receptor (TcR) expression and interactions in development of lymphoproliferation and autoimmunity in lpr and gld mutant mice, and to determine whether these autoimmune mutations affect T cell selection and repertoire formation, we generated mice homozygous for either the gld or the lpr mutation and containing TcR alpha/beta transgenes (Von Boehmer, H., Annu. Rev. Immunol. 1990. 8: 531) specific for the male (H-Y) antigen in the context of H-2Db. Four main results emerged from analysis of these mice. First, expression of transgenic TcR had no effect on disease incidence and progression. Second, the accumulating T cells reflected normal processes of positive and negative selection. Third, cells expressing the transgenic TcR participated equally in lymphoproliferation regardless of whether their antigenic peptide and/or presenting major histocompatibility complex molecules were present or not. Fourth, expression of the TcR transgenes markedly altered the phenotype of the major accumulating lymphocyte subset. Thus, in these models of lymphoproliferation and autoimmunity. T cell repertoire formation proceeds normally, specific T cell recognition of antigen has no effect on the participation of individual clones, and the phenotype of the cells accumulating is sensitive to either the timing or the amount of TcR expression. These results are discussed in the context of the primary cause vs. secondary manifestations of autoimmunity in these models.

Alleles↗
PubMed1992

Both immunity and hyperresponsiveness to Pneumocystis carinii result from transfer of CD4+ but not CD8+ T cells into severe combined immunodeficiency mice.

The opportunistic pathogen Pneumocystis carinii (Pc) is considered to be the leading cause of morbidity in patients with AIDS. It is important, therefore, to determine the immunological mechanisms of resistance to Pc. We have taken advantage of the lack of both T and B lymphocytes in severe combined immunodeficiency (scid) mice to determine the critical factors in resistance to spontaneously acquired Pc pneumonia. Using adoptive transfer of unfractionated or fractionated lymphocyte subsets or hyperimmune serum from congenic normal donors, we have demonstrated that effective immunity to Pc results from the action of CD4+ but not CD8+ T cells (in the absence of antibody) or from humoral immunity (in the absence of T cells). However, responses of CD4+ T cells (but not antibody) to already well-established burdens of Pc are often accompanied by a fatal hyperinflammatory reaction. The activity of CD4+ T cells against Pc thus illustrates a broadly applicable principle that T cell immunity represents a critical balance between consequences beneficial and harmful to the host.

Animals↗
PubMed1992

Lyme borreliosis in genetically resistant and susceptible mice with severe combined immunodeficiency.

The evolution of Lyme borreliosis was examined in genetically resistant C.B-17 and susceptible C3H/He(C3H) mice homozygous for the severe combined immune deficiency (scid) gene, or their immunocompetent counterparts. The C.B-17, C.B-17-scid, C3H, and C3H-scid mice were inoculated intradermally with 10(4) Borrelia burgdorferi and examined on days 14, 21, 30, 45, and 60 after inoculation. Spirochetemia was detected through 30 days, but was cleared in all groups by 45 days. Kidney and brain were inconsistently culture positive, but spleen and ear punch samples were positive in most mice. Immunocompetent C.B-17 and C3H mice seroconverted with equivalent IgG titers to B. burgdorferi, while C.B-17-scid and C3H-scid mice did not seroconvert. Arthritis occurred in nearly all joints examined in all genotypes on day 14, was of equal severity among C.B-17, C.B-17-scid, and C3H mice, but was more severe in C3H-scid mice. By days 30 and 45, arthritis began to resolve in immunocompetent mice, with C3H mice having more severe disease than C.B-17 mice. Arthritis persisted in C.B-17-scid and C3H-scid mice. Carditis occurred to an equal degree in all groups on day 14, remained active in scid mice, but regressed in immunocompetent mice at later intervals. Many spirochetes were visualized with silver stain in inflamed synovial tissues of scid mice, and were present in other tissues in smaller numbers. These studies show that specific immunity is not involved in arthritogenesis or genetically determined susceptibility to arthritis, but is involved in arthritis and carditis regression.

Animals↗
PubMed1991

Cell cycle analysis and DNA aneuploidy in autoimmune mice homozygous for the lpr and gld mutations.

Homozygosity for either of the mutations lpr (lymphoproliferation) or gld (generalized lymphoproliferative disease) in mice results in lymphoproliferation and autoimmune disease. To investigate the site and time of excessive lymphocyte proliferation in these mice, cell nuclei of normal and mutant mice of various ages were stained with propidium iodide and DNA profiles were analyzed by flow cytometry. Two major results were obtained. First, DNA aneuploidy was observed in the lymph nodes and spleen of these autoimmune mice and the cells involved in DNA aneuploidy were predominantly of a CD4-CD8- Thy-1- surface phenotype. Second, although DNA aneuploidy became apparent in mutant mice at 2 mo of age, the numbers of cycling cells were only minimally increased over control levels at all ages tested. Thus, the massive cellular accumulation in the lymph nodes of lpr and gld mice does not seem ascribable solely to excess cell proliferation in these tissues. Moreover, a previously unrecognized cell compartment (CD4-CD8-Thy-1-) characterized by apparent DNA aneuploidy appears in the same tissues and at the same times that the predominant "double negative" (CD4-CD8-Thy-1+) T cell subset accumulates.

Aneuploidy↗
PubMed1991

Unexpected behavior of H2Kb mutant DNAs in denaturing gradient gel electrophoresis.

Denaturing gradient gel electrophoresis (DGGE) is based upon the different melting behaviors of DNA molecules in a chemical denaturant gradient according to their sequences. This technique has recently become a widespread tool to detect mutations. The introduction of a GC-clamp enables the detection of most single base differences between two DNA molecules. As a test system we have applied the polymerase chain reaction (PCR) in combination with DGGE to detect a number of mutations in the mouse H2Kb DNA sequence. A wide variety of spontaneous in vivo mutations of this haplotype have been reported in the C57BL/6J mouse strain and are clustered in the alpha 1 and alpha 2 domains. The combination of PCR and DGGE revealed almost all base changes present in the H2Kb mutants used. However, most of the PCR products of these mutants showed melting behavior which is not easily predicted. We suggest that in addition to current simple theory, which considers that the migration of a DNA molecule in a denaturing gradient depends primarily on its initial melting behavior, additional factors such as secondary structure in partially melted molecules may play a role and can be used to detect mutations.

Animals↗
PubMed1990

Differences defined by bone marrow transplantation suggest that lpr and gld are mutations of genes encoding an interacting pair of molecules.

Homozygosity for either of the lymphoproliferation (lpr) or generalized lymphoproliferative disease (gld) mutations of mice causes the development of systemic lupus erythematosus-like autoimmune syndromes that are characterized by severe lymphadenopathy and highly elevated serum immunoglobulin levels. Although the mutations are nonallelic, analysis of homozygous lpr/lpr and gld/gld mice on the same strain background has indicated that the pathology and severity of the autoimmune syndromes induced by these mutations are indistinguishable. To explain this, it has previously been suggested that lpr and gld may represent mutations in molecules involved in sequential steps of an intracellular metabolic pathway of T cells. We have now investigated the behavior of both lpr and gld in a variety of bone marrow chimeras and have found that functional differences between lpr and gld become apparent after bone marrow transfer. Transfer of lpr/lpr bone marrow to irradiated congenic +/+ recipients caused the development of a graft-vs.-host-like lymphoid wasting syndrome, whereas transfer of gld/gld bone marrow to +/+ recipients resulted in development of a gld-like autoimmune syndrome. Additionally, gld/gld hosts behaved like +/+ hosts irrespective of the genotype of the donor bone marrow, whereas lpr/lpr hosts behaved unlike +/+ hosts when reconstituted with either lpr/lpr, gld/gld, or +/+ bone marrow. These are the first clear differences between these two mutations yet described. Our studies indicate that the molecule altered by the gld mutation is expressed only by bone marrow-derived cells, whereas the molecule altered by the lpr mutation is expressed by both bone marrow-derived cells and by one or more peripheral radioresistant cell populations. To reconcile these differences with the fact that homozygous lpr/lpr and gld/gld mice are indistinguishable, we suggest an alternative model for the relationship between the lpr and gld mutations in which the two molecules affected represent an interacting ligand-receptor pair expressed by different cells.

Animals↗
PubMed1990

Germline V genes encode viable motheaten mouse autoantibodies against thymocytes and red blood cells.

Autoantibodies against thymocytes and RBC may contribute to the pathophysiology of homozygous viable motheaten (mev) autoimmune disease. Whether the production of these autoantibodies in mev mouse results from polyclonal nonspecific B cell activation or specific Ag-driven stimulation is not known. To understand the mechanisms involved in the induction of antithymocyte autoantibody response in mev mouse, we have studied the fine antigenic specificity, structure, and origin of three antithymocyte autoantibodies derived from mev splenic B cell hybridomas. Western blot analysis showed that these mAb bind to polypeptides of 33 and 105 kDa present in RBC and thymocytes, respectively. Additional specificities for the epitopes present in other polypeptides distinguished these three autoantibodies. Northern hybridization and flow microfluorimetry analysis indicated that these hybridomas are derived from the Ly1+ B cell subset. These autoreactive Ly-1 B cell hybridomas, chosen on the basis of their specificity, expressed L chain V genes from a single VK family (VK9) and VH genes from J606 and S107 families. Hybridomas UN34.11 and UN42.5 expressed the VK9 gene identical to that used by peritoneal Ly1+ B cells from various mouse strains and malignant B lymphoma cells secreting anti-mouse RBC treated with proteolytic enzyme bromelin and anti-SRBC antibodies. The third hybridoma, S2-14.2, used a VK9 gene identical to that expressed by MOPC41. None of the VK genes encoding these autoantibodies showed any somatic mutations. In the case of VH genes, the two hybridomas UN42.5 and S2-14.2 derived from two separate fusions, used identical VH genes from the J606 family. The third hybridoma UN34.11 used unmutated V11 germline VH gene, a member of the S107 family. Southern hybridizations, using oligonucleotide probes specific for CDR1 and CDR2, showed that the VH genes encoding the J606 autoantibodies were derived from a germline gene found in the 6.7-kb fragment of EcoRI-digested germline DNA. This germline VH gene is distinct from VH22.1 germline gene that codes for antigalactan antibodies. Sequence analysis of this gene showed perfect homology with the rearranged VH genes confirming the lack of somatic mutations. Thus, our data demonstrate that antithymocyte antibody response occurring in mev mouse is polyclonal and it involves Ly-1 B cells expressing unmutated germline VH and VK genes. These results indicate that antigen driven stimulation may not play an important role in the induction of anti-thymocyte antibody response in mev mouse.

Animals↗
PubMed1990

VH gene family repertoires of "viable motheaten" (mev) mice.

Mutant viable motheaten (mev) mice provide an useful experimental model to study the origin and molecular properties of autoantibodies. In the present investigation we have compared by in situ hybridization VH gene family usage in lipopolysaccharide-activated B cells (available repertoire) and spontaneously immunoglobulin-secreting (actual repertoire) B cells in the spleen of 6-8-week-old BALB/c and mutant BALB/c-mev mice. We have found that while sharing identical available splenic repertoires and expressing a diversified set of VH families, mev mice differ from control BALB/c animals in VH family representation in the actual plasma cell repertoires where they showed a decreased utilization of VH7183 genes and an increased representation of the VHJ606 family when compared to control BALB/c animals. These results indicate that selection of actual repertoires may indeed differ between autoimmune and control mice, but do not establish whether such changes are the primary cause of the disease or whether they are secondary to the initiating of the autoimmune process.

Animals↗
PubMed1990

Bone marrow transplantation from mutant lpr/lpr mice. Functional abnormalities rather than alloantigenic differences appear to determine the development of a graft-vs.-host-like syndrome.

Transfer of bone marrow (BM) from autoimmunity-prone mice homozygous for the lymphoproliferation (lpr) mutation to irradiated congenic +/+ recipients has previously been shown to result in a syndrome similar to chronic graft-vs.-host (GVH) disease. It has been suggested that this syndrome may be due to an antigenic difference caused by the lpr mutation itself or to antigenic differences at loci closely linked to the lpr locus (Theofilopoulos, A. N. et al., J. Exp. Med. 1985. 162:1; Mosbach-Ozmen, L. and Loor, F., Thymus 1987. 9:197). However, the results presented here indicate that alloantigenic differences do not play a role in this syndrome. Instead, the chronic disease observed in lpr/lpr----(+/+) BM chimeras appears to develop as a result of a functional defect associated with the lpr mutation which is expressed shortly after transfer of lpr/lpr BM to irradiated recipients. This defect causes an increase in the levels of serum IgG1 and IgG2, which peak at 4-5 weeks post-transfer and then decline to normal levels by 9-10 weeks post-transfer. Inflammation similar to that observed in classic GVH reactions accompanies excess IgG production in congenic +/+ recipients but not in lpr/lpr recipients of lpr/lpr BM. We demonstrate that the GVH-like response occurring in lpr/lpr----(+/+) chimeras is dependent on mature T cells, but that either lpr/lpr or (+/+) T cells can support this reaction. These results suggest that transfer of lpr/lpr BM to normal mice causes immunoregulatory disturbances which lead to nonspecific activation of T cells. We speculate that lpr/lpr BM causes a GVH-like reaction in +/+ recipients but a systemic lupus erythematosus-like syndrome in lpr/lpr recipients because of intrinsic differences in the +/+ and lpr/lpr host environments. Considering these findings, the lpr/lpr----+/+ GVH model may be useful for analysis of factors capable of inducing undesirable reactions in clinical BM transplantation between nominally histocompatible donors and recipients, in addition to being informative about the nature of the lpr mutation itself.

Animals↗
PubMed1990

Spontaneous Pneumocystis carinii pneumonia in immunodeficient mutant scid mice. Natural history and pathobiology.

The opportunistic pathogen Pneumocystis carinii (Pc) poses a major clinical health problem in individuals with immune deficiency, including those patients with human immunodeficiency (HIV)-associated acquired immune deficiency disease (AIDS). Heretofore, in vivo investigations of the biology of Pc and pathogenesis of pneumocystosis have generally employed steroid-induced immune suppression with antibiotic prophylaxis and protein deprivation. This approach has many drawbacks, chief among them being the widespread, multiple interacting effects caused by the inducing agents. Athymic (nude) mice and rats have been used, but are less than ideal, as the immune defect primarily affects T lymphocytes. This article describes the natural history, pathobiology, and environmental effects on Pc pneumonitis in nonaxenically housed mice homozygous for the autosomal recessive mutation 'severe combined immunodeficiency' (scid), which almost totally lack both cell-mediated and antibody-mediated immune functions. The predictability, unequivocal expression, high morbidity, and well-defined genetic basis make scid/scid mutant mice the model of choice for in vivo studies of spontaneous pneumocystosis.

Animals↗
PubMed1989

Murine "viable motheaten" mutation reveals a gene critical to the development of both B and T lymphocytes.

In lethally irradiated normal mice reconstituted with both normal and autoimmune mutant viable motheaten (mev) bone marrow, the mev-derived B and T cells display aberrant behavior, while those derived from the normal bone marrow develop and function normally. The observed developmental abnormalities of mev B and T lymphocytes are therefore intrinsic to these cell types, rather than being determined by defective influences from the cells' environment. These data bring into question the in vivo significance of reported intercellular regulatory defects in motheaten (me) and mev mice and suggest that these mutations affect a gene whose product acts cell autonomously in the development of several hematopoietic cell lineages including B and T lymphocytes.

Animals↗
PubMed1988

IgE formation and Fc receptor-positive lymphocytes in normal, immuno-deficient, and auto-immune mice infected with Nippostrongylus brasiliensis.

The IgE serum levels and IgE FcR-positive lymphocytes (Fc epsilon R) in the spleen and mesenteric lymph nodes (MLN) of normal and immunologically mutant strains of mice were determined before and 14 days after infection with Nippostrongylus brasiliensis (Nbr) parasites. By IgE rosetting of cells immunofluorescently stained for sIg. Thy-1.2, Lyt-2, and L3T4, only sIg+ IgE rosetting lymphocytes were detected in both normal and Nbr-infected mice. IgE high responder mice had the same percentage of Fc epsilon R+ spleen and MLN lymphocytes as low responder mice. After Nbr infection, the percentages of splenic and MLN Fc epsilon R+ cells increased in parallel to a similar increase of sIg+ B cells. Athymic C57BL/6J-nu mice had 62% Fc epsilon R+ spleen and 85% Fc epsilon R+ MLN cells before and after Nbr infection, but IgE serum levels were less than 5 ng IgE/ml. C57BL/6J mice with the viable moth-eaten mutation mev which have almost exclusively Ly-1+ B cells, had less than 1% Fc epsilon R+ lymphocytes and formed only small amounts of IgE. C57BL/6J mice with the lymphoproliferation (lpr) or generalized lymphoproliferative disease (gld) mutations had low numbers of Fc epsilon R+ cells but formed 15 to 30 times more IgE after Nbr infection than control C57BL/6J mice. The IgE response of mice with the beige mutation (bg) did not differ from control mice. Mice with the xid mutation had few Fc epsilon R+ and sIg+ cells but showed high IgE responses. These data demonstrate that Fc epsilon R are typical cell surface markers for approximately 90% of murine Ly-1-, sIg+ B cells and that the number of Fc epsilon R+ cells does not correlate with the capacity of the mice to form IgE. The IgE response to Nbr infection is normal in mice homozygous for the bg mutation, elevated in mice homozygous for the xid, lpr, and gld mutations, and decreased in mice homozygous for the mev and nu mutations.

Animals↗
PubMed1988

Specificities and V genes encoding monoclonal autoantibodies from viable motheaten mice.

Several hundred hybridomas were obtained from 1-2-mo-old viable motheaten (mev) mice. Among the Ig-secreting hybridomas tested, greater than 50% (17/33) exhibited reactivity for autoantigens, supporting the idea that the Ly-1 B cells that predominate in mev mice contain frequent precursors of autoantibody-forming cells. Certain of the specificities of these autoantibodies correlated with the documented pathophysiology of mev mice (antithymocyte, -erythrocyte, -skin, -kidney, and -IgG); others were specific for autoantigens not previously observed in motheaten mice but though to be involved in other autoimmune diseases (e.g., intrinsic factor, transferrin, myelin basic protein, and thyroglobulin). About 2 of 3 (11/17) of the self-reactive antibodies exhibited multispecific binding activity for various autoantigens. Analysis by Northern blotting of the V gene families used in mev autoantibodies showed a random usage of VH families and a biased usage of four Vk gene families. Of 16 autoantibodies tested, 12 used a Vk gene from the Vk1, 4, 10, or 19 families. These patterns of Vk gene usage differ from nonautoimmune control animals. Overall, an immunoregulatory defect operating at a more generalized level than the VH or Vk loci, and due to a single gene mutation, appears to be responsible for the multiple immune abnormalities of mev mice.

Animals↗
PubMed1987

Ly-1 B helper cells in autoimmune "viable motheaten" mice.

Previous work has demonstrated that Ly-1 B cells from normal C57BL/6J mice help the response of B cell subsets to the 4-hydroxy-3-nitrophenylacetyl hapten (NP). This regulatory cell population, called BH, preferentially helps the expression of plaque-forming B cells which express a predominant set of serologically related determinants collectively known as the NPb idiotype family. The specificity of BH cell activity in the NP system is a reflection of NPb idiotype-specific BH cell surface receptors. Thus, BH cells recognize autologous (i.e., idiotype) antigens. Given these observations and previous associations of increased Ly-1 B cell frequency in autoimmune mice, it was hypothesized that autoreactive Ly-1 BH cells may be present in high frequencies and in an activated state in autoimmune mice. To test this hypothesis the immunologic activity of BH cells in autoimmune viable motheaten (mev/mev) mice was studied. It was determined that splenic BH cells are approximately 10 times more frequent in viable motheaten than normal mice. The fact that BH cells from viable motheaten mice are activated was suggested by the presence of NPb idiotype-specific BH replacing helper activity in sera or B cell supernatants from these autoimmune mice. The soluble helper activities constitutively produced in mev/mev splenic B cell cultures and detected in mev/mev serum were resolved into two moieties, an NPb idiotype-specific immunoglobulin and a nonimmunoglobulin lymphokine(s) fraction. Purified mev/mev B cell-derived B cell maturation factor could substitute for the lymphokine moiety in the NPb idiotype helper cell assay. These results suggest that at least two signals, anti-idiotype immunoglobulin and a late-acting B cell maturation factor, are required for BH-dependent helper activity. The relationships of these results to current concepts of B cell activation mechanisms and the possible association of Ly-1 BH cells with autoimmunity are discussed.

Animals↗