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Biomedical subjects

J H Playfair

Publications and source records attributed to J H Playfair.

153 records · Page 9Linked to original sources
PubMed1965

Focal antibody production by transferred spleen cells in irradiated mice.

Lethally irradiated mice were injected with small numbers of normal spleen cells and then immunized with sheep erythrocytes. Antibody activity was found in their spleens in localized areas whose number corresponded to the number of spleen cells injected. When sheep and pig erythrocytes were injected together, antibody against each was found in separate areas. Each area may consist of the progeny of a single precursor cell, restricted to forming a single antibody.

Animals↗
PubMedDate not supplied

Blood-stage malaria in Biozzi high and low antibody responder mice: the importance of antibody and macrophages in immunity.

Mice from Biozzi high (H) and low (L) antibody responder lines were infected either with non-lethal Plasmodium yoelii 17X, with a lethal variant of the same parasite or with P. chabaudi (non-lethal). H mice recovered from infection with both P. yoelii and its normally lethal variant, whereas L mice died from both. However, L mice showed better initial control of parasitaemia with all three infections. Both H and L mice infected with P. chabaudi showed a similar rapid reduction of parasitaemia once it had reached 40-50%, but L mice were unable to clear the infection completely. When infected with either non-lethal P. yoelii or P. chabaudi, H mice made substantially more antibody than L mice, especially around the time of recovery. The courses of parasitaemia suggest a role for non-antibody factors in early control of infection and for antibody in recovery from P. yoelii. Although antibody was apparently necessary for complete recovery from P. chabaudi, the first rapid fall in parasitaemia appeared to be unrelated to antibody levels.

Animals↗
PubMedDate not supplied

Specific monoclonal IgM is a potent adjuvant in murine malaria vaccination.

Recent experiments in the murine system have indicated that the passive acquisition by offspring of maternal anti-malarial IgG antibodies while conferring some degree of immunity against a primary infection, paradoxically prevents the generation of acquired immunity through vaccination. Therefore, in view of earlier findings concerning the competitive effects of specific IgM and IgG antibodies, we investigated whether specific monoclonal IgM antibodies could be used to potentiate the response to a blood-stage murine malaria vaccine. We now report that small amounts of purified monoclonal anti-parasite IgM can specifically potentiate both priming and memory cell generation in response to vaccination as evidenced by survival after infection, and that the magnitude of this effect is greater than that found with a more conventional nonspecific adjuvant (Bordetella pertussis). Additionally, in offspring of immune mothers, where vaccination is ineffective for up to 8 weeks due to the presence of maternal IgG, we have found that IgM when administered with the vaccine can completely overcome this inhibition by its adjuvant effect.

Adjuvants, Immunologic↗
PubMedDate not supplied

Cytochemical identification of T and B cells in situ in mouse lymphoid tissue and lymph nodes from the rat, gerbil and cat.

The use of enzymes as markers of T or B cells in tissue sections has been studied in mouse lymphoid tissue and lymph nodes from the gerbil, rat and cat. Lymphocytes in the T-cell areas of murine lymph nodes and spleen contained discrete dots of non-specific esterase and N-acetyl-beta-D-glucosaminidase (beta-glucosaminidase) activity, with weak acid phosphatase activity. Lymphocytes in the B-cell areas lacked this discrete staining. Cortical thymocytes contained slight esterase activity while medullary thymocytes were strongly positive for both esterase and beta-glucosaminidase. Lymphocytes with a T-cell staining pattern were only occasionally seen in lymph nodes from Nude (nu/nu) mice. ATPase staining was restricted to lymphocytes in the B-cell areas; weak 5'-nucleotidase staining was only present in a frew lymphocytes in both T- and B-cell areas. Blast cells stimulated by in vivo injection of ConA or PHA in the mouse showed strong discrete enzyme activity for non-specific esterase and beta-glucosaminidase. Lipopolysaccharide-stimulated blast cells and cells within germinal centres lacked this discrete staining. Comparison of lymph nodes from the gerbil, rat and cat suggested at least on enzymes as a T-cell marker in each species although considerable variation in staining profiles was seen in the different species.

Acid Phosphatase↗