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Biomedical subjects

S Leskowitz

Publications and source records attributed to S Leskowitz.

At least 37 records · Page 2Linked to original sources
PubMed1978

Immune response in guinea pigs to two different lipid conjugates of bovine serum albumin.

A lipid conjugate of BSA was made by coupling dodecylamine to the COOH groups of BSA (DA-BSA). Studies on the immunogenicity of this material and one made by coupling dodecanoic anhydride to NH2 groups (D-BSA) demonstrated that cell-mediated immunity could preferentially be generated by lipid conjugation to an antigen as measured by delayed skin reaction, invitro blast transformation, and antibody formation. DA-BSA was found superior by both in vivo and in vitro tests. Both the conjugates retained the ability to suppress delayed type hypersensitivity, but only DA-BSA retained the ability to elicit optimum skin reaction in a sensitized animal and to precipitate anti-BSA antibody.

Animals↗
PubMed1977

The cutaneous basophil response to phytohemagglutinin in chickens.

A cellular infiltrate rich in basophils was observed in chickens in skin sites injected locally with the mitogen PHA. These infiltrating metachromatically granulated cells exhibited features common to mast cells of some species (monolobed nucleus), but also resembled basophils of other species in that they circulated in the blood, and they responded to the PHA mitogen by infiltrating skin test sites. Previous literature suggests that the chicken has a single metachromatic granulated cell and our data support this notion. PHA, a known T cell mitogen, may act by causing the stimulated T lymphocyte to produce a lymphokine that is responsible for the attraction of basophils to the test site.

Animals↗
PubMed1977

Immunologic tolerance to heterologous immunoglobulin: its relation to in vitro filtration by macrophages.

The cellular and molecular basis for the difference in ability of BCG to induce tolerance in BALB/c and DBA/2 mice has been examined by in vitro biofiltration. It was found that incubation with the adherent cells from BALB/c but not DBA/2 spleens could remove the material from BGG which inhibited tolerance induction in BALB/c mice. This material was shown to represent only a trace component in BGG, was present in only certain commercial batches of BGG, and was apparently unrelated to the presence of aggregates or endotoxin.

Animals↗
PubMed1976

Genetic control of cutaneous basophil hypersensitivity.

CBH to DNP-GL could be elicited only in responder guinea pigs which possess the genetic ability to develop classic delayed type hypersensitivity to DNP-PLL, the response to which is governed by the same gene. Since the defect in nonresponder animals seems to reside at the level of their T cells and not B cells, these results lend support to the contention that CBH, as well as DH, is dependent on and probably mediated by T cells.

Animals↗
PubMed1976

The inhibition of cutaneous basophil hypersensitivity reactions by a heterologous anti-guinea pig T cell serum.

Systemic treatment with a heterologous anti-T cell serum of guinea pigs immunized with EA in IFA markedly suppressed CBH reactivity to specific antigen and T cell mitogens, as judged by gross reactivity, histology, and skin histamine. The antiserum produced a marked drop in circulating lymphocytes, mainly at the expense of T cells, as indicated by the ability of surviving lymphocytes to rosette with rabbit RBC. It was postulated that the suppression of CBH reactivity is due to the depletion of T cells, which would have released a factor chemotactic for basophils. The data therefore provide further evidence that cutaneous reactions rich in basophils are primarily dependent on a population of T cells.

Animals↗
PubMed1975

Effect on tolerance induction of the mode of attachment of the hapten the carrier.

In this study we have investigated the role played by the mode of attachment of the hapten on autologous IgG in the induction of carrier-determined tolerance. Three conjugates of the dinitrophenyl hapten and mouse gamma-globulin were prepared: 1) DNP-epsilon-lysine-MGG, 2) DNP-azo-MGG (which binds to histidine and tyrosine), 3) DNP-must-MGG (which binds to the carboxyl groups of glutamic or aspartic acid). DNP was also bound to the immunogenic carrier keyhole limpet hemocyanin (KLH) by the three different linkages. The three DNP mouse-gamma-globulin conjugates were used to induce tolerance and immediately thereafter the animals were immunized with various DNP-KLH conjugates. Antibody response was tested by a modiciation of the Jerne plaque assay. It was found that DNP-epsilon-lysine-MGG induced tolerance to both DNP-epsilon-lysine-KLH and to DNP-azo-KLH. In contrast, neither DNP-azo-MGG nor DNP-must-MGG induced tolerance to DNP-epsilon-lysine-KLH or to DNP-azo-KLH and DNP-must-KLH, respectively. Clearance studies showed no differences in the catabolic rate of the various hapten mouse gamma-globulin conjugates as compared to unconjugated MGG. However, although DNP-must-MGG and DNP-azo-MGG were not tolerogenic, they were immunogenic. In conclusion, this study demonstrated that not only the nature of the carrier but the mode of hapten binding to his carrier are critical for the induction of hapten specific tolerance.

Animals↗
PubMed1975

Strain differences in ease of tolerance induction to bovine gamma-globulin: dependence on macrophage function.

DBA/2 mice are highly susceptible while BALB/c mice are resistant to the induction of tolerance with ultracentrifuged BGG. As measured by the clearance of a test dose of 125-I-BGG, 2 mg ultracentrifuged BGG is sufficient to induce complete tolerance in DBA/2 mice, while BALB/c mice exhibit a clearance rate similar to immune controls. BALB/c mice pretreated with carrageenan (a macrophage toxic agent) lose their resistance to tolerance induction with 2 mg ultracentrifuged BGG, while treatment with cobra venom factor does not alter their resistance to tolerance induction. Stimulation of the reticuloendothelial system with BCG produces a reduction in the susceptibility to tolerance of DBA/2 mice. This effect is transitory, with the maximum effect 3 weeks after BCG infection. Biologic filtration of BGG through BALB/c mice results in a preparation which is highly tolerogenic for recipient mice and this ability to filter the immunogenic portion of BGG is radioresistant. The results provide evidence for the concept that the differential susceptibility to the induction of tolerance is related to a macrophage function in the inductive phase of immunity.

Animals↗