IgE-mediated sensitization to English plantain pollen in seasonal respiratory allergy: identification and partial characterisation of its allergenic components

Characterisation by SDS-PAGE immunoblotting of plantain pollen extract showed that components of 16,000-20,000 M(r) were frequently reactive with IgE antibody in the sera of subjects with seasonal respiratory allergy. Other, more weakly IgE-binding allergens were seen in the range of 40,000-60,000 M(r). HPLC followed by RAST inhibition demonstrated that components of approximately 17,000 M(r) were also responsible for much of the IgE-binding activity of the extract. These components appeared to have pI values between 4.5 and 5.2. RAST inhibition showed that there were no common IgE-binding epitopes in grass pollen and plantain pollen extracts, indicating that skin test responses should not necessarily be interpreted in terms of cross-reaction. 82 subjects with a clinical history of seasonal, respiratory allergy were screened in a skin prick test survey. 28% were skin test positive to plantain pollen extract. The frequency of positive skin test reactions to plantain pollen extract was greater than that to Betula (23%) and Artemisa (16%), both which are considered to be important allergens. In a larger survey positive RAST scores to plantain pollen were given by 34% of sera from subjects with respiratory allergy. Plantain pollen sensitivity should therefore be considered during diagnosis of seasonal allergy.

Regulation of expression of TL genes of the mouse Mhc

The expression of thymus leukemia (TL) antigens and genes in thymocytes and activated T cells was examined by immunoprecipitation, flow cytometric, northern, and nuclear run-off transcription analyses. Cell surface forms of TL were detectable by immunoprecipitation on activated peripheral T cells from Tla haplotypes except Tla(b), in agreement with expression observed on thymocytes. Approximately 40%-50% of concanavalin A (Con A) or anti-CD3-activated T cells were TL+, with expression detected on both the CD4 and CD8 subsets by dual-color analysis. Activated T cells expressed detectable levels of TL mRNA 48 h after stimulation, but no TL transcripts were detectable in unstimulated splenocytes. However, TL mRNA expression in mature activated T cells did not precisely mimic thymocyte expression: the level of expression was considerably lower in activated T cells, and in most haplotypes the transcripts produced in activated T cells appeared to represent a subset of the transcripts produced in thymocytes. By run-off transcription assays in isolated nuclei, TL gene expression was detected in activated but not resting T cells indicating that lack of expression of TL in resting T cells is not due to message instability. These data demonstrate that TL genes are inducible and transcriptionally regulated.

Hypothalamic adrenoceptors concerned with control of temperature, elicited by chemical stimulation

Norepinephrine (NE) and its blockers (alpha-1, alpha-2, beta-1 and beta-2) were micro-injected into the anterior hypothalamus of male albino rats and the effects of these injections on rectal temperature were recorded. The results indicated that the thermoregulatory effects of NE were dependent on ambient temperature. The present study further demonstrated the specific involvement of beta-2 receptors present in the anterior hypothalamus concerned with thermoregulation.

Biochemical differences in Qa-2 antigens expressed by Qa-2+,6+ and Qa-2+,6- strains. Evidence for differential expression of the Q7 and Q9 genes

Cell surface forms of Qa-6 class I molecules are biochemically indistinguishable from Qa-2 although Qa-6 maps telomeric to Qa-2 with the recombinant strain B6.K2. Analysis of appropriate F1 strains did not demonstrate the presence of a trans acting factor that could modify the Qa-2 molecule to produce the Qa-6 determinant. Also, neither a neighboring cell surface molecule nor oligosaccharides were found to block the recognition of the Qa-6 determinant in Qa-2+,6- strains. The 2-D gel profiles of neuraminidase or endoglycosidase treated anti-Qa-2 immunoprecipitates from lysates of cell surface iodinated Qa-2+,6+ strains revealed an additional basic polypeptide which was absent from that of Qa-2+,6- strains. Thus, differential sialylation/glycosylation of Qa-2 molecules masks detection of Qa-2 antigen heterogeneity when cell surface forms are analyzed. Qa-6+ phenotype associated polypeptides were also found at various stages of post-translational processing in cells metabolically labeled in the presence and absence of tunicamycin. Northern analyses using Q7 and Q9 specific oligonucleotide probes revealed appropriate sized transcripts for both genes in the Qa-2+,6+ strain B6 but only Q9 in the Qa-2+,6- strain B6.K2. These data demonstrate that there is structural heterogeneity in Qa-2 antigens expressed by Qa-2+,6+ and Qa-2+,6- strains which results from differential expression of the Q7 and Q9 genes.

Therapeutic drug monitoring. Practical considerations for primary care physicians

Primary care physicians who understand the complexities of drug dosing may be able to provide their patients with more effective pharmacologic therapy. Standard or empirical methods of dosing are appropriate for most agents. The evolution of pharmacokinetics and clinically useful drug assays has led to pharmacokinetic dosing, a more sophisticated and exact method of dosing certain agents.

Interleukin 2 mediates an alteration in the T200 antigen expressed on activated B lymphocytes

We have examined the effect of exogenous IL 2 on cell surface antigen expression in LPS/dextran sulfate-activated murine B cells with the use of a panel of fluorescein-conjugated lectins. Elevated binding of the lectins PNA and SBA to activated B cells was found to be mediated by IL 2-containing supernatants from stimulated EL4 cells as well as by recombinant IL 2. These lectins have specificity for terminal beta-(1-3)-N-acetylgalactosaminyl residues; thus, the quantity or accessibility of these moieties is mediated by IL 2 in activated B lymphocytes. PNA binding in all strains tested, regardless of MHC or background genes, was found to be elevated fivefold to 15-fold by exogenous IL 2. To observe this effect, IL 2 must be added during the first 24 hr of culture. Based on anti-Thy-1 + complement depletion studies, T cells were not required, suggesting a direct effect of IL 2 on B cells. The glycoprotein responsible for this elevated binding of PNA has an Mr of approximately 220K and by immunodepletion was shown to belong to the T200 (Ly-5) family of cell surface antigens. These data demonstrate that exogenous IL 2 can mediate alterations in T200 expression on activated B cells that may be related to IL 2-driven modulation of B cell proliferation and/or differentiation.

Interleukin 2 mediates an alteration in the T200 antigen expressed on activated B lymphocytes

We have examined the effect of exogenous IL 2 on cell surface antigen expression in LPS/dextran sulfate-activated murine B cells with the use of a panel of fluorescein-conjugated lectins. Elevated binding of the lectins PNA and SBA to activated B cells was found to be mediated by IL 2-containing supernatants from stimulated EL4 cells as well as by recombinant IL 2. These lectins have specificity for terminal beta-(1-3)-N-acetylgalactosaminyl residues; thus, the quantity or accessibility of these moieties is mediated by IL 2 in activated B lymphocytes. PNA binding in all strains tested, regardless of MHC or background genes, was found to be elevated fivefold to 15-fold by exogenous IL 2. To observe this effect, IL 2 must be added during the first 24 hr of culture. Based on anti-Thy-1 + complement depletion studies, T cells were not required, suggesting a direct effect of IL 2 on B cells. The glycoprotein responsible for this elevated binding of PNA has an Mr of approximately 220K and by immunodepletion was shown to belong to the T200 (Ly-5) family of cell surface antigens. These data demonstrate that exogenous IL 2 can mediate alterations in T200 expression on activated B cells that may be related to IL 2-driven modulation of B cell proliferation and/or differentiation.

Development of the skin prick test for allergen assay

The allergen skin prick test has been optimised for allergen assay for both D. pteronyssinus and grass pollen extracts. The use of an iterative algorithm to select the linear portion of the transformed dose response curve gave an assay that was stable to changes both in the composition of the panels of atopic subjects and in the time intervals between challenge and response measurement. The coefficient of variation of the assay was 18%. The overall robustness of the assay was shown by an isothermal stability trial in which glycerinated D. pteronyssinus remained comparable with a freeze-dried reference preparation at 5 and 20 degrees C for 3 years. A comparison was also made between the first International Reference Preparation to D. pteronyssinus and 'in house' reference preparations. The skin prick test is thus a valuable bioassay for allergen measurement and can provide a reference assay for the calibration of alternative in vitro assays.