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T M Ellis

Publications and source records attributed to T M Ellis.

138 records · Page 8Linked to original sources
PubMed1983

Dissociation of autologous and allogeneic mixed lymphocyte reactivity by using a monoclonal antibody specific for human T helper cells.

A monoclonal antibody defining a population of human T helper cells was developed and shown to specifically block the autologous mixed lymphocyte reaction (AMLR). This antibody, termed KT69-7 (IgG1), recognized 62% of peripheral blood E rosette-positive (E+) cells while demonstrating negligible reactivity with E- cells, monocytes, granulocytes, EBV-transformed B cell lines, and mouse splenocytes. Separation of E+ cells into KT69-7+ and KT69-7- populations revealed that KT69-7+ T cells provided helper function in PWM-driven B cell differentiation, whereas KT69-7- T cells provided no help and may suppress this response. Modulation of membrane moieties by using KT69-7 or OKT4 plus goat anti-mouse IgG removed reactivity to both these antibodies, suggesting an association between these molecules recognized by these antibodies. In functional studies, KT69-7 selectively blocked the AMLR while demonstrating minimal or no effect on the allogeneic MLR (allo-MLR). Blocking of the autoreactivity occurred when either autologous B lymphocytes or macrophages were used as stimulators. The failure of KT69-7 to block the allo-MLR was not attributable to excessive allogeneic stimulus; KT69-7 failed to block even under conditions of limiting numbers of stimulator cells. KT69-7 thus appears to recognize a molecule on the surface of T helper cells required for recognition of autologous class II antigens.

Animals↗
PubMed1982

Characterization of opsonins for Bacteroides fragilis in immune sera collected from experimentally infected mice.

Serum collected from mice experimentally infected with Bacteroides fragilis 23745 (immune serum) was analyzed for its ability to opsonize the in vitro ingestion of this organism by mouse peritoneal macrophages. B. fragilis was shown to be phagocytized most efficiently in the presence of immune serum although normal mouse serum demonstrated reduced, but significant, opsonic activity. Phagocytosis was greater in the presence of serum collected from animals inoculated twice with the organism than in the presence of serum from once-inoculated animals. The increased opsonic activity of serum from twice-inoculated animals compared to singly inoculated animals was associated with increases in immunoglobulin G1(IgG1), IgG2a, and IgG2b but not IgM. Adsorption analysis of immune serum with homologous or heterologous bacterial antigens indicated that both antibody and complement act synergistically in opsonizing B. fragilis, although either alone may effectively opsonize this organism. Further evaluation of antibody-mediated opsonization revealed that prior treatment of heat-inactivated immune serum with the reducing agent 2-mercaptoethanol caused a slight, but significant, decrease in opsonic activity, thus indicating that IgM is a minor opsonizing antibody for B. fragilis. When ingestion of a B. fragilis stock strain (23745) was compared to a recent clinical isolate (C-1), it was observed that the stock strain was more easily phagocytized in the presence of normal mouse serum, thus suggesting a possible anti-opsonic-phagocytic property of the clinical strain. In addition, the clinical isolate was phagocytized to a significantly greater degree in an aerobic than an anaerobic environment. Subsequent analysis of in vitro killing of B. fragilis 23745 by peritoneal macrophages reflected the previous results in that optimal killing occurred in the presence of immune serum, although normal serum promoted phagocytic killing to an intermediate degree. Thus, these studies implicate both antibody and complement, either alone or in combination, in the opsonization of B. fragilis. Moreover, the virulence of clinical B. fragilis strains may relate to their refractoriness to opsonization and phagocytosis.

Animals↗
PubMed1982

Feline viral rhinotracheitis virus: explant and cocultivation studies on tissues collected from persistently infected cats.

Tissues from 16 feline viral rhinotracheitis (FVR) carrier cats and 15 controls were examined by the techniques of homogenisation, cocultivation and explant cultivation. The tissues examined included trigeminal ganglion and maxillary nerve, olfactory lobe and nerve endings, tonsils, submandibular lymph node, spleen and parotid salivary gland. Most of the cats were shedding FVR virus in the oropharynx at the time the tissues were collected. No evidence of a persistent FVR virus infection was found in any of the tissues. Trigeminal ganglion explant cultures from six FVR virus carrier cats were shown to be latently infected with feline syncytia forming virus by treatment with 5-iododeoxyuridine. Five control cats had trigeminal ganglion explant cultures similarly treated but produced no evidence of infection. The possible significance of this is discussed.

Animals↗
PubMed1981

Potentiating effect of HLA matching and blood transfusion on renal allograft survival.

An analysis of HLA (A and B) recipient-donor matching on the outcome of 105 cadaver kidney transplants performed at the Medical College of Virginia transplant center revealed that there is a significant, overall difference (P = 0.03) between recipients receiving kidneys mismatched at two or less HLA loci versus recipients mismatched at three or more loci, the fewer mismatch category showing a better graft survival. The effect of blood transfusion prior to transplantation was studied and found to improve the outlook, especially in the best matched groups. The number of transfusions does show a significant effect (P = 0.04) in the subgroup of patients with two or less mismatches, but for patients with three or more mismatches, the number of transfusions does not seem to matter (P = 0.83). However, in this study even the allografts mismatched at three or more loci had a 1-year graft survival of greater than 65%, indicating that factors other than HLA or blood transfusion play significant roles in the graft outcome. Although the findings are based on a somewhat small number of patients, the statistical significance suggests a potentiating effect of HLA matching and blood transfusion on renal allograft survival.

Antilymphocyte Serum↗
PubMed1981

Feline respiratory virus carriers in clinically healthy cats.

In two surveys, feline calicivirus was cultured from 19.7% and 15% of 66 and 201 clinically healthy cats respectively. Feline viral rhinotracheitis virus was cultured also from 1.5% of oropharyngeal swabs collected in both surveys. Feline syncytial virus was isolated from 5.5% oropharyngeal swabs collected in the second survey. The use of serological examination and corticosteroid treatment to stimulate virus shedding demonstrated that 25.8% cats in the first survey were carriers of feline viral rhinotracheitis virus. In the second survey, mercapto-ethanol treatment of serum was used to differentiate recent from previous infection with feline viral rhinotracheitis virus and some 18.5% cats had FVR antibody that was resistant to treatment with mercapto-ethanol.

Animals↗