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Biomedical subjects

E J Steele

Publications and source records attributed to E J Steele.

At least 37 records · Page 2Linked to original sources
PubMed1991

The adjuvanticity of Algammulin, a new vaccine adjuvant.

Algammulin is a suspension of 1-2 microns ovoids of the immune stimulant gamma inulin (g-IN) in which alum is embedded as a carrier for protein or other anionic antigens. Tests for specific IgG and seroconversion responses in mice immunized with keyhole limpet haemocyanin (KLH) show that the presence of g-IN on the alum has increased its adjuvanticity 6- to 17-fold (p less than 0.001), and thus has a synergistic effect. A mixture of alum and g-IN was no more active than alum alone. Low KLH doses at borderline seroconversion levels (0.1-1 microgram/mouse) allow comparison with a vaccine situation. The improved Algammulin responses extended to 58 days after primary doses and to memory recall after boost at 65 days. At 1 mg Algammulin i.p. in primary and secondary doses the anti-KLH IgG responses were equal to those from Freund's complete adjuvant. The g-IN on the alum increased all responses tested (IgG 1, 2a, 2b, 3 and total IgG, IgM, IgA and IgE), but changed the emphasis from that of alum (favouring mostly IgG 2a, IgG 2b and IgA).

Adjuvants, Immunologic↗
PubMed1991

IgM natural autoantibodies against bromelain-treated mouse red blood cells recognise carbonic anhydrase.

Carbonic anhydrase (CA) from mouse erythrocyte membranes is recognised as an autoantigen in Western blotting experiments with FUB 1, a murine IgM monoclonal antibody that binds both phosphatidylcholine and bromelain-treated mouse red blood cells (BrMRBC). Serum from mice stimulated with lipopolysaccharide (LPS-serum) also recognises CA. From SDS-PAGE, and blotting experiments with whole mouse erythrocytes, we found two closely spaced glycoprotein bands in the 30 kD region that reacted with both FUB 1 and LPS-serum. One of the molecular weight markers, bovine carbonic anhydrase which is of a molecular weight of about 30 kD, electrophoresed in the same 30 kD region also reacted with these antibodies. Carbonic anhydrases from a range of mammalian species were found to be crossreactive with FUB 1 and LPS-serum by Western blotting, whereas human glycophorin A and human asialoglycophorin were not recognised by the antibodies. FUB 1 specifically recognises both native and denatured bovine carbonic anhydrase in ELISA assays. The serological identity of the determinants of CA and BrMRBC was confirmed by specific absorption of both FUB 1 and LPS-serum with BrMRBC and normal mouse erythrocytes. We propose that a native autoantigenic epitope on erythrocytes may be revealed by the proteolytic action of bromelain and that this determinant is associated, at least in part, with carbonic anhydrase.

Animals↗
PubMed1990

Distribution of mutations around rearranged heavy-chain antibody variable-region genes.

The mechanism of somatic hypermutation in the variable region of immunoglobulin genes expressed in mammalian B cells is a major unexplained phenomenon in the generation of diversity in the immune system. To evaluate possible mechanisms, the distribution of somatic mutations was examined for a group of five cloned, rearranged, somatically mutated VH genes generated in C57BL/6j mice. These mutated VH genes were sequenced and compared with their germ line counterparts from a point approximately 550 base pairs upstream of the transcription start site to an EcoRI site some 1,200 base pairs downstream of JH-4. The location of the transcription start (cap) sites was also precisely determined. Most (greater than or equal to 94%) of the 118 mutations scored occurred between the transcription start site and the distal end of JH-4. However, seven mutations occurred upstream of the transcribed region, and at least four were found downstream of JH-4. The target region for the mutator mechanism therefore clearly extends into the 3' nontranslated and 5' nontranscribed regions. Thus, models which propose the transcribed region of the DNA as the sole substrate for the mutation process are not ruled out but are inadequate to explain the upstream distribution of somatic mutations.

Animals↗
PubMed1988

IgM anti-erythrocyte autoantibodies specific for buried and neo-antigens using cellular-ELISA assays.

The aim was to develop a cellular-ELISA assay to detect natural autoantibodies specific for bromelain-treated mouse red blood cells (BrMRBC). High, unexpected IgM titres against normal mouse red blood cells (NMRBC) were detected in day 7-14 sera of CBA mice treated with E. coli lipopolysaccharide (LPS). These "autoantibodies" bound to normal mouse red blood cells in the presence or absence of commonly used c-ELISA adhering agents. Such high reactivity to NMRBC was never detected using complement dependent haemolytic assays in earlier work in this system. The question whether these IgM alpha-NMRBC molecules were binding nonspecifically (via Fc) or specifically (via Fab) was answered indirectly by comparing the binding titres of LPS-stimulated serum and several purified IgM antibody preparations (alpha-PC, alpha-KLH, MOPC 104E) on the same antigen coated plates. The observed binding ratios (titre on antigen X: titre on NMRBC) varied widely between different antibody sources, indicative of specific binding. In addition no significant unequivocal binding against NMRBC could be detected in vivo (LPS-stimulated mice) nor could bound IgM antibody be detected in a suspension-c-ELISA assay (high binding titres to BrMRBC could be detected in the latter test system). In conventional c-ELISA assays, modification of normal erythrocyte by adhesion to plastic microtitre plates appears to expose or create "neoantigens" on NMRBC which are not encountered in suspension-type c-ELISA, nor in lytic or agglutination assays where the erythrocyte targets are in suspension at physiological pH and isotonicity.

Animals↗
PubMed1988

Observations on offspring of mice made diabetic with streptozocin.

My objective was to determine the effect of streptozocin (STZ)-induced diabetes in male inbred mice on nonfasting blood glucose levels and body weights of offspring. Hyperglycemia was induced in CBA/H male mice by either multiple subdiabetogenic doses (MD) of STZ (5 doses/day of 50 mg STZ/kg body wt) or by a single high sublethal (SD) dose (200 mg STZ/kg body wt). Females were made diabetic by the multiple low-dose procedure. The following matings were set up: SD males with normal (NOR) females; MD males with NOR females; NOR males with MD females; MD males with MD females. Controls were matings of NOR males with NOR females. Among the first cohort of litters was born one female from the cross of an SD male with an NOR female who became spontaneously hyperglycemic at 5 wk of age; the female progeny of this cross had significantly lower body weights. All other progeny groups were normoglycemic (up to 5 wk) and had normal body weights. Test progeny weaned in the second and subsequent cohorts of litters were also normoglycemic. The major effect in this progeny group was on body weight; diabetic fathers (particularly MD males) mated with NOR females produced offspring with significantly higher juvenile body weights than the controls (increase of approximately 0.5 g). These body-weight distributions also appeared more homogeneous than the more variable body-weight distribution of the controls. In contrast, MD mothers (mated with NOR males) produced second-cohort offspring with significantly lower average body weights (decrease of approximately 1-2 g) than the controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1987

Hypothesis: somatic hypermutation by gene conversion via the error prone DNA----RNA----DNA information loop.

A mechanism to explain somatic hypermutation in immunoglobulin variable region genes is proposed employing polynucleotide information transfer through the error prone DNA----RNA----DNA loop. During transcription of the rearranged V-region, the primary transcript undergoes either inappropriate termination, cleavage, or reverse transcriptase priming allowing a V-region specific reverse-transcriptase-integrase complex to synthesize a DNA copy of the rearranged V-region and integrate it, by homologous recombination, back into the normal chromosomal site. Some consequences and predictions of the hypothesis are discussed.

Animals↗
PubMed1984

Acquired paternal influence in mice. Improved reproductive performance of CBA/H males immunized with rat blood cells.

Adult male CBA/H mice immunized against rat blood cells displayed a significant improvement in reproductive efficiency of 50% and 26% in two breeding programmes in relation to control male breeders exposed to phosphate-buffered saline (PBS). (Both types of male were mated to normal CBA/H females.) The improvement was reflected in the significant increase in successful mating frequency and size of litters produced. The unknown mechanism of this phenomenon is discussed in relation to the known reproductive consequences of conventional genetic crosses.

Animals↗
PubMed1984

Acquired paternal influence in mice. Altered serum antibody response in the progeny population of immunized CBA/H males.

First generation offspring derived from CBA/H males immunized in adult life against rat blood cell antigens displayed altered immune reactivity to rat erythrocytes (RE) as assayed at a single time point after challenge. For the low antigen challenge doses employed (10(6) to 10(7) RE i.p.) the population of test offspring showed a significant enhancement of serum antibody response relative to the control population of progeny of unimmunized males; at higher antigen challenge doses (10(8) RE i.p.) the response in the test progeny population was suppressed.

Animals↗
PubMed1982

Islet allografting without immunosuppression: reversal of insulitis-associated diabetes and a case of spontaneous juvenile onset diabetes in mice.

The development of juvenile onset diabetes may involve an autoimmune response causing an insulitis and beta cell destruction. It has been suggested that replacement of the host's beta cells by transplantation may lead to the destruction of the new tissue by the same processes which caused the destruction of the original beta cells. This study does not support this proposal. It was possible to reverse insulitis-induced diabetes and spontaneous murine 'juvenile onset' diabetes by transplantation of cultured islet allografts. The grafts survived and maintained normoglycaemia for periods in excess of 100 days.

Animals↗
PubMed1982

The reversal of diabetes by pancreatic islet transplantation.

In this paper the theoretical basis of alloreactivity and its relevance to transplantation biology is discussed prior to a review of work showing that culture of adult mouse pancreatic islets for 7 days in 95% O2 and 5% CO2 facilitates successful grafting to nonimmunosuppressed allogeneic recipients. These allografts function by reversing both chemically induced and spontaneous diabetes. The fetal mouse pancreas is more immunogenic than adult islets, and even after a culture period of 10 days in 95% O2 and 5% CO2, BALB/c allografts are consistently rejected by nonimmunosuppressed recipient mice. The immunogenicity of fetal pancreas is thought to be due to the presence of contaminating lymphoreticular cells in the mesentery surrounding the fetal pancreas. Digestion of the fetal pancreas with collagenase allows the isolation of proislets that develop into functional islet tissue on transplantation. Fetal proislets are less immunogeneic than the whole fetal pancreas and may provide a source of tissue for clinical transplantation. Established islet allografts are relatively stable and are not rejected following nonspecific stimulation of the recipient's immune system or following passive transfer of either antibody or antibody and complement. After prolonged residence in the recipient a state of allograft tolerance develops and such grafts resist rejection by specific stimulation of the recipient. The administration of donor antigen in the form of uv-irradiated cells enforces this state of allograft tolerance.

Age Factors↗
PubMed1981

Simultaneous yet independent inheritance of somatically acquired tolerance to two distinct H-2 antigenic haplotype determinants in mice.

We have previously presented evidence that somatically acquired immunological tolerance to foreign histocompatibility antigens induced in male inbred mice can be transmitted at a high frequency to first- and second-generation offspring without exposure of the progeny to the tolerizing antigenic stimulus. These data have in turn been interpreted to support a hypothesis predicting soma to germ-line inheritance for acquired states of the immune system. Formal proof of this genetic scheme at the molecular level is not yet available. However, an even stronger reason for abandoning the notion of the isolation of the germ line from the soma (Weismann's doctrine) would be provided by a clear demonstration of the multiple inheritance of independently acquired somatic characters. Here we present evidence that individual male mice (B10) made tolerant to two different H-2 haplotypes (B10.BR, B10.D2) can transmit the tolerance state to each haplotype independently, yet often simultaneously, at a high frequency to both first and second generation progeny.

Animals↗
PubMed1981

Ontogeny of the autoimmune reaction in normal mice to antigens in erythrocytes and gut.

Normal mice have large numbers of cells (PFC) making antibody to an autoantigen which is exposed when their own erythrocytes are treated with proteolytic enzymes. Antibody against this antigen can be demonstrated in serum by haemolysis tests against the treated cells; this antibody rises to high levels within 2 to 3 days after injection of E. coli lipopolysaccharide. using quantitative absorption tests we have located the 'bromelain mouse' (BrM) autoantigen in the gastrointestinal tract as well as in erythrocytes; this distribution pattern resembles that of classical blood group antigens. We have described the ontogenetic development of PFC, B cells capable of activation by LPS, serum antibody and antigen. Free antigen is found in the gut shortly after birth. B cells rise rapidly to high levels in the peritoneal cavity, but require a short period of culture to release detectable antibody. PFC and B cells increase more slowly in spleen to adult levels by 3 weeks of age. The serum antibody lags behind PFC development. The pattern is consistent with an early stimulation of B cells in the peritoneal cavity by gut-derived antigen. We discuss the possible relationship of this autoimmune response to high natural responses against other autoantigens in mice, man and other species.

Animals↗
PubMed1980

Inheritance of acquired immunological tolerance to foreign histocompatibility antigens in mice.

CBA mice were rendered tolerant of major histocompatibility antigens of A/J mice by neonatal injection of 100 x 10(6) lymphoid cells of (CBA X A/J)F1 followed by repeated injections of F1 cells at 2-week intervals throughout the study. When adult (8 weeks old), 10 tolerant or normal CBA males were mated to normal CBA females. Spleen cells of the progeny were tested for their ability to mount a cytotoxic T lymphocyte response in vitro against A/J antigens or against C57BL/6J and B10.A (2R) antigens in a cell-mediated lympholysis (CML) assay. A significant proportion (50-60%) of first-generation offspring of tolerant fathers failed to produce detectable anti-A/J cytotoxic responses but responded in the normal range to stimulation by C57BL/6J or B10.A (2R). Second-generation offspring derived from mating animals born of tolerant male parents--either brother x sister matings (incross or matings to normal CBA mice (outcross)--also showed a high proportion (20-40%) with diminished anti-A/J CML responses when similarly tested in vitro. Thus, a specific acquired somatic characteristic in the immune system (tolerance to major histocompatibility antigens) induced in male mice shows significant transmission to first- and second-generation offspring.

Animals↗