Biomedical subjects

M Semma

Publications and source records attributed to M Semma.

22 records · Page 2Linked to original sources

PubMed1981

Regulation of delayed-type hypersensitivity (DTH) response to hen egg-white lysozyme (HEL).

Delayed-type hypersensitivity (DTH) can be demonstrated in A/J mice immunized with hen egg-white lysozyme (HEL) in complete Freund's adjuvant (CFA) by challenging primed animals in the ear with aqueous HEL. Normal A/J mice receiving soluble HEL derivative peptide, P-Ib, sequence 29-54 and 109-123 linked by a single S-S bond, 7 days prior to immunization with HEL showed much lower DTH response specific to the protein. The inhibition of DTH reactivity is due to active suppression and involves the generation of suppressor T-cells (Ts). Thus, the suppression induced with a single i.v. injection of P-Ib solution was able to be transferred into syngeneic recipients by the spleen cells from mice pretreated with P-Ib. These suppressor cells are T-cells, since their ability to suppress DTH is completely abrogated by treatment wit anti-Thy 1.2 and complement. Amongst HEL derivative peptides tested in the present study, only P-Ib could induce the tolerance.

Animals↗

PubMed1981

Idiotypic analysis of antibodies to hen egg-white lysozyme (HEL). III. Further studies on the idiotypic cross-reactivity among anti-HEL antibodies in mice.

An isolated antibody preparation directed to the native hen egg-white lysozyme (HEL) from a single A/J mouse (#a-11), termed IDHELa-11, was inoculated into rabbits to produce anti-idiotypic sera (anti-Id). The antisera were extensively absorbed with normal A/J Ig to render then idiotype specific. Radioimmunoassay utilizing 125I-IdHELa-11 and the anti-ID sera (R103 and R104) was performed to examine the idiotypic cross-reactivity of the humoral immune response to HEL in various mouse strains and other animal species. Idiotypes shared by IdHELa-11 were detected in the sera of five mouse strains tested, but not in any of the examined sera of other animal species such as rats, goats, guinea pigs, or sheep, indicating the occurrence of species-specific cross-reactive idiotypes (CRI) of antibodies to HEL. Our experiments also suggested the presence of intrastrain CRI. The present experiments, along with our earlier results (15), suggest that idiotypic cross-reactivity among murine antibodies to HEL appears to be weak. Thus when R103 and R104 were the anti-Id sera used, the frequency of occurrence of CRI shared by IdHELa-11 in 5 micrograms of anti-HEL antibody in strain A mice was 74 ng and 111 ng; in other strains it was 25-44 ng and 60-98 ng, respectively.

Animals↗

PubMed1981

Suppression of hen egg-white lysozyme (HEL)- specific delayed -type hypersensitivity responses in mice by suppressor T cells after neonatal administration of anti-idiotypic antibodies.

Anti-idiotypic rabbit antiserum (anti-Id) directed to the idiotypes of anti-hen egg-white lysozyme (HEL) antibody froma single C3H mouse (No. 2) was shown to be capable of recognizing only a fraction of the anti-HEL antibody populations produced by other C3H mice. Experiments were performed to examine the effect of this particular anti-Id on the delayed-type hypersensitivity (DTH) response specific for the same protein antigen. A group of 60-day-old C3H mice which had been administered anti-Id within 24 hr after birth were tested for HEL-DTH response. The results indicated that the DTH response was completely suppressed by the anit-Id treatment. The inhibition of DTH reactivity is due to active suppression and involves the generation of suppressor T cells. Thus, the suppression induced with a single injection of anti-Id was transferable with both spleen cells and thymocytes from mice, that received anti-Id. These suppressor cells are T cells since their ability to suppress DTH is completely abrogated by treatment in vitro with anti-Thy 1.2 serum and complement.

Animals↗

PubMed1981

Idiotypic analysis of antibodies to hen egg-white lysozyme (HEL). II. Distribution and frequency of occurrence of idiotypes shared by A/J anti-HEL antibody.

Anti-HEL Ab from one A/J mouse (No. a-4),Ida-4(HEL), was s.c. inoculated into rabbits to induce anti-idiotypic (anti-Id) sera. After absorption with normal A/J Ig, two anti-Id serra (R101 and R102) were obtained. The interaction between 125I-Id(a-4)(HEL) and anti-Id sera was completely inhibited by unlabelled Ida-4(HEL), but not by non-specific Ig. The anti-Id sera were used to investigate the distribution of A/J (No. a-4) anti-HEL idiotypes in sera obtained from HEL-immunized animals. Idiotypes shared by Ida-4(HEL) were also detected in the sera of five examined mouse strains, but not in any of the examined rat, guinea-pig, goat, and sheep sear. Our experiments suggest the presence of inter- as well as intrastrain idiotype in mice. However, cross-reactivity appeared to be weak. When R101 and R102, respectively, were the anti-Id sera used, the frequency of occurrence of Ida-4(HEL) in stain A wa 1/106 and 1/53; in other mouse strains it was 1/277 and 1/85.

Animals↗