Biomedical subjects

J A Frey

Publications and source records attributed to J A Frey.

4 recordsLinked to original sources

PubMed1977

Transfer of delayed hypersensitivity in mice to microbial antigens with dialyzable transfer factor.

Dialyzable Lawrence-type transfer factor was prepared from the spleen cells of CF1 mice inoculated with Coccidioides immitis- and Candida albicans-killed vaccines and with live Mycobacterium tuberculosis vaccine (BCG). These preparations were shown to transfer antigen-specific cell-mediated immunity to naive mice, as measured by the delayed skin test and footpad-swelling methods. Reactivity could be demonstrated when the test antigens were given 24 h after the transfer factor, but not when they were given simultaneously. Coccidioides-specific transfer factor was shown to be sensitive to Pronase and resistant to trypsin and ribonuclease. A preparation of BCG transfer factor was sensitive to snake venom phosphodiesterase.

Animals↗

PubMed1977

Susceptibility of murine transfer factor to dimerized ribonuclease A.

Dialyzable transfer factor was prepared from the spleens of CF1 mice actively sensitized with killed Coccidioides immitis antigen. The transfer factor was administered to normal mice either intraperitoneally or into the hind footpads. The recipient mice were tested for reactivity to the coccidioides antigen and to Candida albicans antigen by means of the footpad swelling test. The transfer factor conferred antigen-specific reactivity upon normal recipient mice when given by the intraperitoneal and footpad routes. This capacity of the transfer factor was destroyed by in vitro pretreatment with dimerized ribonuclease A, an enzyme active against double-stranded, as well as single-stranded, ribonucleic acid. In contrast, monomeric ribonuclease A, which is active against only single-stranded ribonucleic acid under the conditions used here, was without effect upon the transfer factor. These data provide evidence that murine transfer factor contains ribonucleotides that are essential for immunological activity. In addition, the data are consistent with the hypothesis, advanced by others, that the ribonucleotides may be double-stranded or uniquely looped configurations.

Animals↗

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↗

PubMed1976

Delayed hypersensitivity to fungal antigens in mice. II. Characterization of the active component in immunogenic RNA extracts.

In a mouse model, cell-mediated immunity to Coccidioides immitis, as assayed by the delayed hypersensitivity skin test, was transferred with whole immunogenic RNA extract and its greater than 33S and 6S-13S sedimentation fractions. Both fractions were cleaved by RNase, but the products retained their transfer activity. The greater than 33S fraction of immunogenic RNA extract was inactivated by pronase, whereas the 6S-13S fraction was resistant to the proteolytic enzyme; however, after RNase treatment the latter fraction was sensitive to pronase. This finding suggests a protective role for RNA. Dialysis of immunogenic RNA extract yielded a dialysate with a ratio of absorbance at 260 nm to that at 280 nm (A260:A280) of 1.02. Similarly, the dialysis product of RNase-treated RNA is active and has an A260:A280 ratio of 1.34. The data indicate that at least part of the active moiety of immunogenic RNA extracts is an RNA-associated, pronase-labile peptide or nucleopeptide. Furthermore, it is possible that the dialyzable transfer factor may be the same peptide or nucleopeptide cleaved from immunogenic RNA during preparation of the transfer factor.

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