scholarly journals IMMUNE RESPONSE OF RABBITS TO INJECTION OF PLASMODIUM KNOWLESI

1939 ◽  
Vol 70 (2) ◽  
pp. 131-139 ◽  
Author(s):  
Monroe D. Eaton ◽  
L. T. Coggeshall
Keyword(s):  
Immune Response ◽  
Plasmodium Knowlesi ◽  
Conclusive Evidence ◽  
Red Cells ◽  
Rabbit Serum ◽  
Normal Rabbit Serum ◽  
Passive Protection ◽  
Normal Monkey ◽  
Protective Antibodies

Specific complement-fixing antibodies are produced in the serum of rabbits in response to injections of living or dead Plasmodium knowlesi. Sera from rabbits receiving injections of either parasitized or normal monkey erythrocytes are parasiticidal in vitro for P. knowlesi. Because absorption of parasiticidal rabbit sera with normal monkey erythrocytes abolishes the parasiticidal effect, it is concluded that the effect is largely due to an antibody to the red cells. Normal rabbit serum is not parasiticidal. Experiments on passive protection in monkey malaria with serum from rabbits which have received intraperitoneal injections of living or dead P. knowlesi yield no conclusive evidence that protective antibodies are formed.

scholarly journals Enterococcal surface protein contributes to persistence in the host but is not a target of opsonic and protective antibodies in Enterococcus faecium infection

2010 ◽  
Vol 59 (9) ◽  
pp. 1001-1004 ◽  
Author(s):  
I. G. Sava ◽  
E. Heikens ◽  
A. Kropec ◽  
C. Theilacker ◽  
R. Willems ◽  
...  
Keyword(s):  
Enterococcus Faecium ◽  
Passive Immunization ◽  
Surface Protein ◽  
Lipoteichoic Acid ◽  
Polyclonal Antiserum ◽  
Clinical Isolates ◽  
Rabbit Serum ◽  
Normal Rabbit Serum ◽  
Protective Antibodies

Enterococci are important nosocomial pathogens with multiple intrinsic and acquired resistances to antibiotics. In the past, the majority of infections were caused by Enterococcus faecalis; however, an increase in Enterococcus faecium clinical isolates has been observed in recent years. The enterococcal surface protein (Esp) is expressed on the surface of most E. faecium clinical isolates and has been shown to be involved in biofilm formation. Here, E. faecium E1162 and its previously created insertion-deletion mutant of the esp gene, E. faecium E1162Δesp, were compared in a mouse bacteraemia model. Anti-Esp serum was tested for its capacity to mediate opsonophagocytic killing of E1162 in vitro and to protect against E. faecium bacteraemia. The inactivation of esp attenuated E. faecium virulence with reduced numbers of bacteria recovered from the kidneys in animals infected with the mutant compared to the wild-type strain (P=0.035). Passive immunization with rabbit polyclonal serum raised against the recombinant N-terminal Esp protein did not protect mice against E. faecium bacteraemia (P>0.05). In contrast, mice passively immunized with polyclonal antiserum raised against lipoteichoic acid (LTA) from E. faecalis had lower numbers of E. faecium E1162 in the blood compared to mice immunized with normal rabbit serum. These results suggest that Esp contributes to E. faecium persistence in the host. However, in contrast to LTA, Esp does not seem to be a target for protective antibodies in E. faecium strain E1162 in mouse bacteraemia.

scholarly journals Immunologic stimulation of early murine hematopoiesis and its abrogation by cyclosporin A

Blood ◽  
1982 ◽  
Vol 59 (4) ◽  
pp. 851-856 ◽  
Author(s):  
SA Burstein ◽  
SK Erb ◽  
JW Adamson ◽  
LA Harker
Keyword(s):  
Immune Response ◽  
Cyclosporin A ◽  
Progenitor Cells ◽  
Pokeweed Mitogen ◽  
Normal Rabbit Serum ◽  
Lymphocyte Function ◽  
Spleen Cells ◽  
Stimulation Of

Abstract Mice injected chronically with antiplatelet serum develop an increase in the number of megakaryocytic progenitor cells compared to animals given normal rabbit serum. To examine the specificity of this response, progenitor cells giving rise to megakaryocyte, granulocyte-macrophage, erythroid, and mixed-cell colonies were assayed after injection of various heterosera or saline. All four colony types increased in the serum-treated groups. Since the in vitro proliferation of hematopoietic progenitor cells is promoted by supernatants of mitogen-stimulated spleen cells, we hypothesized that the immune response following antiserum administration resulted in the in vivo activation of T lymphocytes which produced or led to the production of colony stimulating activities. To test this hypothesis, cyclosporin A, a preferential inhibitor of T lymphocyte function, was given to mice concurrently with antiserum and also added to spleen cell cultures in the presence of pokeweed mitogen. Cyclosporin A abrogated the antiserum- related increases in progenitor cell numbers in vivo and the production of colony stimulating activity in vitro. The results suggest that the immune response related to antiserum administration results in the in vivo production of hematopoietic colony stimulating activities that may be identical to those produced in vitro by mitogen-stimulation of spleen cells.

Release of bioactive ACTH by perifused human placenta at early and late gestation

1993 ◽  
Vol 136 (2) ◽  
pp. 345-353 ◽  
Author(s):  
B. J. Waddell ◽  
P. J. Burton
Keyword(s):  
Human Placenta ◽  
Late Gestation ◽  
Rabbit Serum ◽  
Maximal Response ◽  
Normal Rabbit Serum ◽  
Apparent Difference ◽  
Adrenocortical Cells ◽  
Adult Rats ◽  
Constant Rate

ABSTRACT This study assessed whether bioactive ACTH is released by the human placenta during perifusion in vitro at early and late gestation. Human placental villous fragments from early (8–12 weeks) and late (38–40 weeks) gestation were perifused at a constant rate for 6·5 h. To assess ACTH-like bioactivity released by this tissue, the perifusion effluent was redirected through adjacent chambers containing freshly dispersed adrenocortical cells obtained from adult rats. Baseline secretion of corticosterone by these adrenocortical cells averaged 95±26 (s.e.m.) fmol/min, and this increased at least fivefold (P <0·01, two-way ANOVA) in response to placental effluent at early and late gestation. The magnitude of this increase, expressed as a percentage of the maximal response to a subsequent stimulus with ACTH(1–24), was similar for placentas obtained at early (41 ± 12% of maximal response) and late (42 ± 17%) gestation. Immunoreactive (I)-ACTH was readily detectable in placental effluent from all preparations (5·5±2·3 fmol/min per g tissue), and there was no apparent difference with stage of gestation. To determine whether all of the ACTH-like bioactivity released by the placenta was attributable to I-ACTH, a second series of placental/adrenal perifusions was conducted. In these, I-ACTH was selectively removed from placental effluent by immunoneutralization, and the residual bioactivity measured. Immunoneutralization involved preincubation of placental effluent with ACTH antiserum (1:100), and preincubation with normal rabbit serum (NRS) served as a control. Preincubation with ACTH antiserum, but not with NRS, resulted in a marked reduction in ACTH-like bioactivity present in placental effluent at both early (P <0·01, paired t-test) and late (P <0·05) gestation. This inhibition was significantly more effective (P <0·05, unpaired t-test) at early than at late gestation. Overall, these data establish that the human placenta can release bioactive ACTH-like activity at both early and late gestation, and that much, but not all, of this bioactivity is directly attributable to I-ACTH. These findings clearly demonstrate a potential role for placental ACTH in directly influencing the maternal and/or fetal hypothalamic-pituitary-adrenal axes during human pregnancy. Journal of Endocrinology (1993) 136, 345–353

scholarly journals THE NATURE OF THE VIRUS RECEPTORS OF RED CELLS

1948 ◽  
Vol 87 (4) ◽  
pp. 315-328 ◽  
Author(s):  
George K. Hirst
Keyword(s):  
Influenza Virus ◽  
Type A ◽  
Red Cells ◽  
Rabbit Serum ◽  
Normal Rabbit Serum ◽  
Virus Inhibitor ◽  
Virus Receptors

Evidence has been offered that influenza virus which has been heated at 56°C. for 30 or more minutes loses some of its capacity to agglutinate red cells and may completely lose its power to elute from cells on which it has been adsorbed. Such heat-inactivated virus does not possess the capacity to destroy the virus inhibitor in normal rabbit serum and this appears to be the explanation of the higher agglutinin inhibitory levels obtained with serum and heated virus as compared with serum and untreated virus. The heat-inactivated virus can be used to measure the inhibitor substance in normal rabbit serum. By two different methods it has been demonstrated that the inhibitor is destroyed in the presence of unheated influenza virus, as measured by inhibition titrations with virus inactivated at 56°C. The destruction of inhibitor by virus of either type A or B can be measured by virus of either type with similar results.

Partial purification of antigens collected during in vitro cultivation of the larval stages of Taenia pisiformis

Parasitology ◽  
1976 ◽  
Vol 72 (3) ◽  
pp. 269-279 ◽  
Author(s):  
M. D. Rickard ◽  
J. C. Katiyar
Keyword(s):  
Protective Immunity ◽  
Culture Medium ◽  
Serum Proteins ◽  
Skin Tests ◽  
Rabbit Serum ◽  
Partial Purification ◽  
In Vitro Cultivation ◽  
Normal Rabbit Serum ◽  
Skin Reactions

SummaryLarvae of Taenia pisiformis were cultured in vitro in medium containing 2·5, 5 or 20% (v/v) of normal rabbit serum (NRS). Greatest development occurred in 20% NRS, and the potency of antigens collected in medium from each culture tested by intradermal (i/d) skin tests in infected rabbits paralleled the in vitro growth rate of larvae. ‘Culture’ antigens from 5% NRS stimulated good immunity in rabbits to a challenge infection with T. pisiformis eggs, although they were poorly reactive in skin tests.T. pisiformis larvae were also cultured in 10% (v/v) of nitrates of serum reduced to one-half of its volume by passage through 300 000 MW cut oif (XM300F) or 100000 MW cut off (XM100F) ultrafiltration membranes. Larvae cultured using XM300F had growth rates comparable with those cultured in 20% NRS, and the antigens released into the culture medium had equal potency in i/d tests and in stimulating protective immunity in rabbits. Larvae did not develop in XM100F orproduce skin-reactive or protective antigens.Crude ‘culture’ antigen from cultures in 20% NRS was separated into 4 fractions by nitration on Sephadex G200. All of these fractions gave i/d skin reactions in infected rabbits. Fraction 3 (F3) was the most active, but was shown by acrylamide gel electrophoresis and immunoelectrophoresis to be highly contaminated with rabbit serum proteins. F3 was separated into fractions on DEAE-Sephadex A50, and the third fraction from this was as active as the original culture medium in i/d skin tests, but had only 5% of the original protein concentration. Electrophoresis demonstrated few serum contaminants, and 2 indistinct protein bands that were not present in a similar fraction of NRS.Neither Sephadex G200 F3 nor DEAE-Sephadex F3 stimulated protective immunity in rabbits, suggesting that antigens stimulating immunity against the establishment of T. pisiformis in rabbits and those provoking cell-mediated immune reactions may be different.

scholarly journals EFFECT OF p30 RECOMBINANT PROTEIN ON AFRICAN SWINE FEVER VIRUS IN VITRO REPRODUCTION

2018 ◽  
pp. 3-7 ◽  
Author(s):  
Ali Mazloum ◽  
I. Yu. Zhukov ◽  
A. S. Pershin ◽  
A. S. Igolkin ◽  
N. N. Vlasova
Keyword(s):  
Cell Culture ◽  
Immune Response ◽  
Recombinant Protein ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Viral Proteins ◽  
E Coli ◽  
Virus Reproduction ◽  
Protective Antibodies

African swine fever specific prevention means have not been developed yet. However, it is necessary to study the function of definite viral proteins, their role in immune response morphogenesis and induction to determine the components to be included into ASF protection drugs. It was established that p54 and p30 proteins participate in virus penetration and internalization and are able to induce protective antibodies in immunized pigs. The inoculation of these proteins into ASFV-infected cell culture has an impact on virus reproduction to different extents. The results of the study of purified recombinant protein p30 effect, derived from E. coli clone, containing pET32b(+)/р30 plasmid, on ASFV in vitro reproduction are presented. The greatest decrease, including complete inhibition of virus reproduction, was observed when 300 ng of p30 were inoculated into porcine spleen and marrow primary cell cultures, infected with the ASFV Krasnodar 07/17 isolate at the dose of 100 HAU per plate (~ 0.01 HAU per cell). It was noted that if the mixture of p30 and p54 was inoculated into a sample, the virus reproduction was greater compared to the use of only p30.

scholarly journals Immunologic stimulation of early murine hematopoiesis and its abrogation by cyclosporin A

Blood ◽  
1982 ◽  
Vol 59 (4) ◽  
pp. 851-856 ◽  
Author(s):  
SA Burstein ◽  
SK Erb ◽  
JW Adamson ◽  
LA Harker
Keyword(s):  
Immune Response ◽  
Cyclosporin A ◽  
Progenitor Cells ◽  
Pokeweed Mitogen ◽  
Normal Rabbit Serum ◽  
Lymphocyte Function ◽  
Spleen Cells ◽  
Stimulation Of

Mice injected chronically with antiplatelet serum develop an increase in the number of megakaryocytic progenitor cells compared to animals given normal rabbit serum. To examine the specificity of this response, progenitor cells giving rise to megakaryocyte, granulocyte-macrophage, erythroid, and mixed-cell colonies were assayed after injection of various heterosera or saline. All four colony types increased in the serum-treated groups. Since the in vitro proliferation of hematopoietic progenitor cells is promoted by supernatants of mitogen-stimulated spleen cells, we hypothesized that the immune response following antiserum administration resulted in the in vivo activation of T lymphocytes which produced or led to the production of colony stimulating activities. To test this hypothesis, cyclosporin A, a preferential inhibitor of T lymphocyte function, was given to mice concurrently with antiserum and also added to spleen cell cultures in the presence of pokeweed mitogen. Cyclosporin A abrogated the antiserum- related increases in progenitor cell numbers in vivo and the production of colony stimulating activity in vitro. The results suggest that the immune response related to antiserum administration results in the in vivo production of hematopoietic colony stimulating activities that may be identical to those produced in vitro by mitogen-stimulation of spleen cells.

Studies on the growth of 5-day-old rabbit blastocysts in vitro

Development ◽  
1965 ◽  
Vol 13 (1) ◽  
pp. 83-95
Author(s):  
Joseph C. Daniel
Keyword(s):  
Blastocyst Stage ◽  
Culture Conditions ◽  
Rabbit Serum ◽  
Young Rabbit ◽  
Normal Rabbit Serum ◽  
Excellent Growth ◽  
Growth Promoting ◽  
Initial Medium ◽  
Made In

Rabbit embryos at the early blastocyst stage (5 days post coitum) do not grow well in vitro. The present studies were undertaken for the purpose of defining some of the components of the medium that are optimal for growth of young rabbit blastocysts under culture conditions. Preliminary studies showed that the cell culture medium F10 (Ham, 1963a) supported excellent growth of a variety of rabbit cells in vitro. Rabbit blastocysts would grow, although not at the normal rate, in F10 supplemented with 15 per cent, normal rabbit serum. F10R15 was therefore selected as the initial medium to which additions or alterations were made in an attempt to perfect its blastocyst growth-promoting qualities. It should be clearly understood that throughout this paper the word ‘growth’, used in reference to rabbit blastocysts, means an increase in blastocyst volume without prejudice to the issue of whether or not the total volume or mass of living cells is also increasing.

scholarly journals INTERACTIONS BETWEEN RABBIT POLYMORPHONUCLEAR LEUCOCYTES AND STAPHYLOCOCCI

1959 ◽  
Vol 110 (3) ◽  
pp. 419-443 ◽  
Author(s):  
Zanvil A. Cohn ◽  
Stephen I. Morse
Keyword(s):  
Bacterial Species ◽  
Rabbit Serum ◽  
Normal Rabbit Serum ◽  
Polymorphonuclear Leucocytes ◽  
Bacterial Inactivation ◽  
Intracellular Killing ◽  
Positive Strain ◽  
Simultaneous Evaluation ◽  
Coagulase Positive Staphylococci

A method has been described for the study in vitro of leucocyte-bacteria interactions which permits the simultaneous evaluation of both phagocytosis and intracellular bacterial inactivation. Employing this technique, the fate and localization of staphylococci in homogeneous suspensions of rabbit polymorphonuclear leucocytes have been studied. Coagulase-positive strains of S. aureus were not efficiently ingested in the presence of normal rabbit serum. In contrast, coagulase-negative strains of S. albus were rapidly engulfed and inactivated. Immune sera prepared against a coagulase-positive strain enhanced the the ingestion of the homologous organism as well as of three heterologous strains of S. aureus. Following phagocytosis, prompt intracellular killing of S. aureus occurred. The thermostable opsonins in immune sera reacted only with strains of S. aureus. A comparison between polymorphonuclear leucocytes obtained from normal and immune animals revealed no differences in their ability either to ingest or kill coagulase-positive staphylococci. Studies with other bacterial species are presented to illustrate: (a) phagocytosis followed by intracellular inactivation; (b) phagocytosis followed by intracellular survival; and (c) the absence of phagocytosis.

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