THE ROLE OF COMPLEMENT IN THE PASSIVE CUTANEOUS REACTION OF MICE

Intradermal injection of mice with ribonuclease antibody, followed by intravenous injection with ribonuclease, resulted in permeability increase, demonstrable by "blueing." The size of the blued area depends on the quantity of antibody injected and on the interval between the two injections. If antigen was injected first and antibody was injected subsequently, a similar increase in permeability was observed in animals having a complete complement system (MuB1-positive) and in animals which have a deficient complement system (MuB1-negative). Marked differences in response were observed between these two types of mice if antigen was injected some hours after the antibody. In MuB1-negative mice, a blueing reaction was not observed at intervals between injections (2½ hours if 3 µg N antibody and 15 hours if 25 µg N antibody were injected intradermally) at which MuB1-positive animals showed a marked permeability increase. At these intervals, blueing did occur in MuB1-negative animals if they were injected with the serum of MuB1-positive mice or with fresh guinea pig serum. Blueing was not induced if the serum of MuB1-negative mice or heated guinea pig serum was injected. The occurrence of two distinct phases of the cutaneous reaction, of which only one involves the complete hemolytic complement system, was deduced from these observations

IMMUNOSUPPRESSIVE AND GRAFT-REJECTING ANTIBODIES IN HETEROLOGOUS ANTI-LYMPHOCYTIC SERUM

Skin allografts survived longer on ALS-treated, complement-deficient (C5 negative) recipients than on ALS-treated, complement-competent (C5 positive) recipients. Administration of C5-positive serum to C5-negative, ALS-treated recipients resulted in reduced graft survival. A percentage of grafts from ALS-treated, C5-positive donors was rejected when transferred to untreated syngeneic recipients; this was not observed when C5-negative, syngeneic animals served as ALS-treated donors and untreated recipients. It was concluded that ALS has graft-rejecting properties which are promoted by late acting complement components. Unlike ALS-mediated graft rejection, ALS-mediated immunosuppression appeared to be independent of the late acting complement components. The effect of ALS on the humoral response to sheep erythrocytes was examined in complement-deficient and complement-competent mice. Immune-suppression was determined by ALS treatment of C5-competent and C5-deficient mice and also by transfer of in vitro ALS-treated spleen cells from C5-negative and C5-positive donors to cyclophosphamide-treated recipients. The ability of ALS to depress the humoral response to sheep cells and to decrease immunological competence of spleen cells was the same in the presence as in the absence of C5

DISTRIBUTION, INHERITANCE, AND PROPERTIES OF AN ANTIGEN, MUB1, AND ITS RELATION TO HEMOLYTIC COMPLEMENT

An antigen, MuB1, present in the sera of some mice, can elicit a precipitating antibody in certain other strains of mice. An antibody to the antigen MuB1 can also be elicited in rabbits. 99 strains and substrains of inbred mice were tested for the presence of MuB1; the antigen was found in the sera of 44 strains (61 per cent) and 14 DBA substrains (52 per cent). Evidence is presented indicating that mice lacking MuB1 do not make a modified antigen, corresponding to MuB1, but are genetically deficient in synthetic ability at this site. By reaction with antibody to MuB1 an antigen corresponding to MuB1 was found in 13 of the 15 orders of mammals, and in 63 of 85 mammalian species tested, including man and guinea pig. The quantity of the antigen MuB1 is always greater in the serum of male than in the serum of female mice. The concentration of MuB1 increases with age; this increase is more marked in male than in female mice. By means of backcross experiments it was shown that the inheritance of MuB1 is unifactorial, is independent of the inheritance of the gamma globulin allotype MuA2, and is qualitatively independent of the sex of the parents. The antigen MuB1 is found in the euglobulin fraction of serum; it loses its ability to precipitate with antibody after heating at 56°C, but not after treatment with ammonia or hydrazine. By gel filtration, MuB1 is separated with a fraction containing molecules of molecular weight ≈ 150,000. An empirical correlation was observed between the presence or absence of MuB1 in the sera from inbred mice and the presence or absence of hemolytic complement (Hc), as measured by a test using a high concentration of rabbit hemolysin. In backcross experiments also, a correlation between hemolytic complement and the presence of MuB1 was demonstrated. As with MuB1, male mice had a higher hemolytic complement level than females. The particular component of complement which may be identical with MuB1 has not been identified

PECAM-Independent Thioglycollate Peritonitis Is Associated With a Locus on Murine Chromosome 2

Background: Previous studies have demonstrated that knockout or inhibition of Platelet/Endothelial Cell Adhesion Molecule (PECAM, CD31) in a number of murine strains results in impaired inflammatory responses, but that no such phenotype is seen in the C57BL/6 (B6) murine background. Methodology/Principal Findings: We have undertaken a quantitative trait locus (QTL) mapping effort between FVB/n (FVB) and B6 mice deficient for PECAM to identify the gene or genes responsible for this unique feature of B6 mice. We have identified a locus on murine chromosome 2 at approximately 35.8 Mb that is strongly associated (LOD score = 9.0) with inflammatory responses in the absence of PECAM. Conclusions/Significance: These data potentiate further study of the diapedesis machinery, as well as potential identification of new components of this machinery. As such, this study is an important step to better understanding the processes of inflammation

A sensitive flow cytometric methodology for studying the binding of L. chagasi to canine peritoneal macrophages

BACKGROUND: The Leishmania promastigote-macrophage interaction occurs through the association of multiple receptors on the biological membrane surfaces. The success of the parasite infection is dramatically dependent on this early interaction in the vertebrate host, which permits or not the development of the disease. In this study we propose a novel methodology using flow cytometry to study this interaction, and compare it with a previously described "in vitro" binding assay. METHODS: To study parasite-macrophage interaction, peritoneal macrophages were obtained from 4 dogs and adjusted to 3 × 10(6 )cells/mL. Leishmania (Leishmania) chagasi parasites (stationary-phase) were adjusted to 5 × 10(7 )cells/mL. The interaction between CFSE-stained Leishmania chagasi and canine peritoneal macrophages was performed in polypropylene tubes to avoid macrophage adhesion. We carried out assays in the presence or absence of normal serum or in the presence of a final concentration of 5% of C5 deficient (serum from AKR/J mice) mouse serum. Then, the number of infected macrophages was counted in an optical microscope, as well as by flow citometry. Macrophages obtained were stained with anti-CR3 (CD11b/CD18) antibodies and analyzed by flow citometry. RESULTS: Our results have shown that the interaction between Leishmania and macrophages can be measured by flow cytometry using the fluorescent dye CFSE to identify the Leishmania, and measuring simultaneously the expression of an important integrin involved in this interaction: the CD11b/CD18 (CR3 or Mac-1) β2 integrin. CONCLUSION: Flow cytometry offers rapid, reliable and sensitive measurements of single cell interactions with Leishmania in unstained or phenotypically defined cell populations following staining with one or more fluorochromes

The Birch Bark Sings

Cinader describes the use of birch bark by Native cultures in order to convey stories and spiritual meanings. 23 bibl. ref