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At least 37 records · Page 2Linked to original sources
PubMed1976

Delayed hypersensitivity to fungal antigens in mice. II. Molecular classes in immunogenic RNA extracts that transfer delayed hypersensitivity.

The transfer of delayed hypersensitivity to Coccidioides immitis and Candida albicans antigens with immunogenic RNA extracts was studied in a mouse model. Sensitivity was measured by skin tests and footpad swelling responses. Immunogenic RNA converted normal spleen cells in vitro so that they produced antigen-specific delayed hypersensitivity in mice that were given injections of the cells. RNase reduced the rate of, but did not abolish, in vitro interaction of immunogenic RNA extracts with lymphocytes. Immunogenic RNA transferred sensitivity on direct intraperitoneal inoculation into mice. The transfer ability was resistant to RNase preparations active against both single- and double-stranded RNA. Sedimentation gradient fractions of the immunogenic RNA were assayed by intraperitoneal injection, and converting activity was found in two fractions, greater than 33S and 6S-13S. After treatment with RNase, all activity was shifted to the less than 6S fraction. Two fractions of the immunogenic RNA in its native state (greater than 33S and 6S-13S) were also able to convert spleen cells. The data indicate that the transfer of delayed hypersensitivity by immunogenic RNA preparations is associated with RNA but may not require the intact RNA molecule.

Animals↗
PubMed1981

Delayed hypersensitivity to Staphylococcus aureus in mice: characterization of a membrane immunogen involved in delayed hypersensitivity.

Staphylococcal membrance proteins are potent initiators of delayed hypersensitivity following multiple subcutaneous injections of viable organisms. When the membranes are separated by exclusion chromatography they separate into three distinct fractions, one of which was responsible for the elicitation of footpad (FP) reactivity in sensitized mice. The active immunogen was characterized as a glycoprotein having a molecular weight of approximately 15,600 Daltons, with the peptide and carbohydrate moieties linked by covalent bonding. In vitro spleen cell stimulation and macrophage migration inhibition studies revealed that the active FP fraction was also the immunogen involved in these responses. The immunogenic fraction also had mitogenic properties as evidenced by the stimulation of non-sensitized spleen cells. These data characterize a glycoprotein present in Staphylococcus aureus cell membrane which is both immunogenic and mitogenic and is the principal immunogen responsible for the early delayed hypersensitivity response.

Animals↗
PubMed1977

Studies on delayed hypersensitivity in mice. I, Physicochemical and biological properties of preferential antigens for inducing delayed hypersensitivity in mice.

Variously modified protein antigens were tested by footpad assay to clarify the effect of these medications in producing delayed hypersensitivity in mice. The most potent antigen examined was carboxyl-methylated serum albumins. These antigens were highly basic proteins and hydrophobic compared with native serum proteins. They stimulate humoral antibody response in mice poorly, and remain at the subcutaneous injection site much longer than native serum albumins. In vitro tests of susceptibility of thymus and spleen cells and peritoneal macrophages to the antigens revealed that methylated serum albumins possessed the stimulatory activity to the latter and were toxic to the former. As for macrophage, fluorescein-labelled methylated serum albumin showed an affinity to their membrane and were phagocytosed, but FITC-BSA did not show any affinity to the macrophages. These biological activities to tissue or cells may be contributable to render methylated serum albumins to induce and elicit delayed hypersensitivity preferentially in mice.

Animals↗
PubMed1978

Delayed hypersensitivity in mice induced by intravenous sensitization with sheep erythrocytes: evidence for tuberculin type delayed hypersensitivity of the reaction.

Delayed hypersensitivity (DH) reaction can be induced in mice by intravenous sensitization with sheep erythrocytes (SRBC). However, as the sensitizing procedure is quite different from a usual mode of sensitization for DH using complete Freund's adjuvant (FCA), the nature of this reaction has been a matter of controversy. In an attempt to characterize this reaction, we placed special interest on two possibilities regarding the nature of this reaction; Jones-Mote reaction or tuberculin type DH. From the kinetics study on the DH after challenge, the DH reaction to SRBC in mice by intravenous sensitization was clearly distinguished from the Arthus reaction. The dose-response pattern of this reaction also suggested that the contribution of Arthus reactivity to delayed reactivity was negligible. Cell reconstitution experiments revealed this DH to be quantitatively thymus cell dependent. Furthermore, this DH required macrophages at its manifestation stage, and appearance of basophil infiltration at the lesion was absent. In addition, strain difference and ageing of host mice influenced the DH reaction in exactly the same fashion in which these factors influence the tuberculin type-DH induced by subcutaneous sensitization with methylated human serum albumin (MHSA) in FCA. Taken collectively, it was concluded that this DH reaction can be categorized as the tuberculin type.

Aging↗
PubMed1977

Studies on delayed hypersensitivity in mice. III. Evidence for suppressive regulatory T1-cell population in delayed hypersensitivity.

T-T-cell interactions involved in delayed hypersensitivity (DH) response have been studied by employing delayed foot pad assay to methylated human serum albumin in C57BL/6J mice. The DH response, one of the T-cell manifestations of cell-mediated immune response is suppressively regulated by T cells and such observation was based on studies of age-associated kinetics of foot pad reaction and effects of cell transfer and adult thymectomy on developing DH response. These suppressively regulatory T cells in DH have a life span of less than 4 wk and a constant derivation from the thymus is required. Such cells are numerous in the young mouse thymus and few in the spleen and thymus of old mice. On the one hand, the presence of a long-lived effector T-cell population was suggested in DH. These cells are numerous in the spleen and are low responders to phytohemagglutinin in vitro. It is assumed that these suppressive T cells interact with antigen-reactive cells at their proliferating stage by recognition of the iodiotypic difference through surface receptors. As in the case of graft-vs.-host and humoral response in vivo, three different subsets of immune competent cells participate in the DH response. These cells consist of one specifically antigen-reactive T cell, one suppressive regulatory T cell, and one bone marrow-derived cell, a macrophage that responds to a chemical mediator from sensitized effector T cells and that develops a DH skin lesion nonspecifically.

Aging↗
PubMed1996

Definition of a Trichophyton protein associated with delayed hypersensitivity in humans. Evidence for immediate (IgE and IgG4) and delayed hypersensitivity to a single protein.

Dermatophytes of the genus Trichophyton cause infections of human skin, nails, and hair. Unlike most Ags, Trichophyton can elicit either immediate (IH) or delayed (DH) hypersensitivity skin reactions. Previous studies isolated a 30-kDa Ag (Tri t 1) that caused IH skin tests. The study presented here used skin testing and in vitro T cell proliferation assays to monitor purification of an Ag, designated Protein IV, associated with DH reactions. Protein IV was purified by cation exchange HPLC; amino acid sequence analysis of the N-terminus and nine internal peptides (143 residues) revealed no homologies to Tri t 1 or to any other known proteins. A mAb-based ELISA was developed to measure Protein IV. Protein IV elicited DH skin reactions in subjects with a history of athlete's foot but also caused IH skin reactions. Serologic responses to Protein IV were studied in 59 adults who had been skin tested with Trichophyton extract. IH skin reactions were associated with a positive RAST (14/23) as well as with specific IgE (13/23) and IgG4 (14/23) Abs to Protein IV. DH skin tests were not associated with IgE or IgG4 Abs. IgE anti-Protein IV Abs were quantitatively correlated with IgG4 Abs (r = 0.57, p < 0.001). Specific IgG Abs to Protein IV were highest in IH subjects (gm = 230 U/ml), and lowest in those with DH (gm = 91 U/ml) or negative (gm = 81 U/ml) skin tests; furthermore, the prevalence of IgG Abs increased significantly with age. Protein IV is the first defined protein associated with both DH and IH skin reactions; these reactions are characterized by distinct serologic responses. The results establish that diverse immune responses in humans can be directed against the same protein.

Adult↗
PubMed1979

Interaction among IgE-mediated hypersensitivity reaction, PCA reaction and delayed hypersensitivity reaction (at local skin sites of monkeys).

The effect of the IgE-mediated reaction on the passive cutaneous anaphylaxis (PCA) reaction was studied at local skin sites of monkeys, and we found that the IgE-mediated reaction appeared to enhance the PCA reaction. Interactions among IgE-mediated reaction, PCA reaction and delayed hypersensitivity reaction were also determined. Contact dermatitis induced with DNCB was utilized as the delayed hypersensitivity reaction. The IgE-mediated reactior or PCA reaction, as well as simple serum irritation, enhanced the delayed hypersensitivity reaction. It is thus assumed that the IgE-mediated reaction enhances the PCA reaction and that this in turn accelerates the delayed hypersensitivity reaction.

Animals↗
PubMed1985

Delayed hypersensitivity and immune protection against herpes simplex virus: suppressor T cells that regulate the induction of delayed hypersensitivity effector T cells also regulate the induction of protective T cells.

We have been studying delayed hypersensitivity (DH) to herpes simplex virus (HSV) in order to examine the role of this response in host defense against acute and recurrent HSV infections. In previous reports the basic parameters of DH to HSV have been characterized by using a murine ear swelling model, and also the regulation of DH to HSV induced by i.v. injection of the virus. In this paper, we describe a murine protection system and our use of the ability to specifically regulate DH to HSV to examine the correlation between T cells that transfer DH (TDH) and cells that transfer protection from acute HSV infection. Both DH and protection can be transferred with lymph node cells from mice immunized subcutaneously 4 days previously. The effector cell appears to be a T cell, because serum from these donors confers no protection and treatment of immune cells with anti-Thy-1.2 plus complement reduced their ability to protect. Tolerance of DH to HSV was induced by i.v. injection 7 days before subcutaneous immunization. Tolerized mice were unable to generate protective cells. Furthermore, tolerized mice contained suppressor T cells that suppressed not only DH but also the development of protective cells. Regulation of protective cells was shown to be virus specific, because mice tolerized with vesicular stomatitis virus (VSV) were not impaired in their ability to generate T cells that protected from HSV infection. The correlation between the TDH cell and cells that transfer protection from acute HSV infection is discussed.

Acute Disease↗