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At least 325 records · Page 18Linked to original sources

Natural immunity in the oncornavirus-infected mouse.

BALB/cfC3H females neonatally infected with mammary tumor virus (MTV) possess spleen cells capable of significant cytotoxic activity against target MTV-induced mammary tumor cells in microcytotoxicity assay. Spleen cells from supposedly MTV-free BALB/c females are also specifically reactive, as a result of horizontal transmission of MTV antigens. No quantitative differences in reactivity exist between females not susceptible to the development of mammary tumors (BALB/c) and those that may develop or already have tumors (multiparous BALB/cfC3H). However, there are qualitative differences in response between those at risk and those not at risk.

Age Factors↗

Natural immunity in cats to feline leukemia viral antigens.

An isotopic antiglobulin assay was developed to measure antibodies in "normal" cats to FOCMA, a cell surface antigen associated with immunity to FeLV-induced tumors. The assay was shown to be specific for detecting FOCMA antibody by several criteria including a correlation with cell membrane immunofluorescence and absorption tests. Antibody to FOCMA developed following FeLV infection and was expressed in heterologous species. In combination with an assay for antibody to FeLV p30, the major virion structural protein, 200 cats sera from three different geographic areas were examined for evidences of FeLV-type-C-virus infection. Approximately 17% of all sera examined contained antibody to FOCMA. Antibodies directed to the FeLV p30 were detected in 8 of the sera and only in cats with FOCMA antibody. The correlation in cat sera between antibody to FOCMA and FeLV p30 antigen suggests that both are associated with the same process, infection with FeLV type-C-virus. The relationship of the observed pattern of antibody response is discussed in relation to other horizontally transmitted RNA-containing viruses.

Animals↗

[Change in the natural immunity of mice after administration of blastolysin, a glycopeptide from the Lactobacillus bulgaricus cell wall].

The effect of blastolysin, a glycopeptide of the cell walls of L. bulgaricus, on the resistance of mice to infections caused by S. typhimurium and B. pertussis, lysozyme levels in the blood serum and 5'-nucleotidase activity of peritoneal macrophages was studied. The changes in the nonspecific resistance of mice due to the effect of blastolysin depended on the administration route and the type of the developing infection. It activated the enzymatic activity of the peritoneal macrophages and changed the lysozyme levels in the blood serum of mice. The optimal protective effect of blastolysin was achieved on intramuscular injection in a dose of 100 micrograms.

5'-Nucleotidase↗

The role of easily released substances (ERS) from bacteria in physiologic solution in natural immunity. VI. Induction of opsonins for different genera of bacteria by ERS from Staph. aureus oxford.

ERS obtained from Staph. aureus by mild extraction with physiologic saline solution possess activity of inducing nonspecific opsonins which react with homologous bacteria and with related Gram-negative bacteria. ERS from Staph. aureus weakly stimulated precipitins and antibodies active in passive hemagglutination and induced a marked rise in agglutinin titers especially for the homologous strain and Gram-negative S. typhimurium bacilli. N-acetyl-D-glucosamine absorbed the opsonizing factor for various bacteria with heterologous activity.

Acetylglucosamine↗

[Further study of the hormonal regulation of natural immunity to weak transplantation antigens in inbred mice].

Blood plasma corticosterone level and the extent of immunological reaction to sex-antigen of skin transplant in inbred mice CBA, C57Bl/6, F1 (CBA X 57Bl/6), C3H, AKR was compared. Mice CBA had a high blood plasma corticosterone level and no immunological reaction to sex-antigen. A lower blood corticosterone level and the presence of reaction to sex-antigen was characteristic of mice C57Bl/6, AKR, C3H, F1(CBA X C57Bl/6). The number of endogenous colonies in the spleen of mice CBA was less than in mice C57Bl/6. Mice CBA had a narrow cortical thymus layer in comparison with the wide thymus cortex of mice AKR and C57Bl/6. Adrenalectomy of mice CBA caused a sharp widening of the thymus cortex.

Adrenalectomy↗