Intrathymic nurse cell lymphocytes can induce a specific graft-versus-host reaction.

Single chicken thymic nurse cells (TNC) placed onto the chorionallantoic membrane (CAM), showed that intra-TNC lymphocytes (TNC-L) possess a strong graft-versus-host reactivity (GVHR) in allogeneic MHC combinations. This reaction shows the morphological, phenotypic, and functional characteristics of a classical GVH reaction (GVHR). The induction of a GVHR was significantly higher for TNC-L as compared with thymocytes or peripheral blood lymphocytes (PBL). The specificity of the GVHR was shown by serial transfer experiments onto appropriate allogeneic and syngeneic secondary embryonic hosts. In immunofluorescence analyses with monoclonal antibodies (mAb) to the chicken alpha/beta and gamma/delta T cell receptors (TCR) and the CD3, CD4, and CD8 equivalents, an enrichment of CD3+/CD4+/CD8- and CD3+/CD-4-/CD8+, TCR-alpha/beta + and TCR- gamma/delta + cells was observed inside TNC as compared with extra-TNC thymocytes. A large proportion of CD4+ and/or CD8+ TCR- gamma/delta + cells were demonstrated inside TNC. A minor population among TCR- gamma/delta extra-TNC thymocytes also expressed CD4 and/or CD8 molecules. Based on functional tests and double staining experiments, we propose that CD4+/CD8+ thymocytes enter the TNC where they may undergo positive selection for MHC restriction and further differentiation to CD4 or CD8 single-positive cells. Taken together these data support the concept that TNC contribute a specialized thymic microenvironment for T cell differentiation and maturation.

Antibody development to viral and allogeneic tumor cell-associated antigens in patients with malignant melanoma and ovarian carcinoma treated with lysates of virus-infected tumor cells.

Pre- and postimmunization sera from six malignant melanoma and six ovarian carcinoma patients were used to investigate the humoral immune response to antigens expressed in extracts of allogeneic tumor cells and lysates of these same cells infected with virus. Nitrocellulose paper replicas of cell extracts, fractionated by polyacrylamide gel electrophoresis, were used as antigenic targets. Antibodies that bound to tumor cell antigens of defined molecular weight were identified with enzyme-linked probes specific for human immunoglobulins G, A, and M. Prior to therapy, all sera reacted with one or more antigens expressed by the unmodified tumor cells. Postimmunization sera from two malignant melanoma patients and one ovarian carcinoma patient reacted with antigens in extracts of uninfected tumor cells. These same antigens were not detected by preimmunization sera. Most postimmunization antibody responses were directed against antigens associated with the infecting virus itself and antigens found in extracts of virus-infected but not in extracts of uninfected tumor cells. These results suggest that treatment with lysates of virus-infected allogeneic human tumor cells elicits humoral immune responses against: (a) tumor cell-associated antigens; (b) antigens that are specifically virus associated; and (c) antigens that may be virus induced or virus modified cytoplasmic or nuclear antigens.

Chemical linkage of erythrocytes and viral antigen in the hemolysis-in-gel (HIG) test for viral antibodies.

The sensitivity of the hemolysis-in-gel (HIG) test with rubella antigen is not improved by chemical linkage of the virus to the erythrocytes, and after such modification, IgM specific antibodies are not detectable. In the influenza HIG test with tetraazotized o-dianisidine (TOD), chromic chloride and potassium periodate as coupling reagents, increased sensitivity was observed with allantoic fluid of infected eggs as antigen. If Tween-ether treated hemagglutinin is used in the HIG test, zones of hemolysis are detectable only after treatment of the erythrocytes with TOD, chromic chloride and potassium periodate.

Genetic susceptibility of indigenous chicks to subgroup A Rous sarcoma virus inoculated via the chorioallantoic membrane.

An investigation was made using chicks of two Indian indigenous breeds of fowl, Kadaknath and Aseel, to ascertain genetic resistance to infection by Rous sarcoma virus of subgroup A. A standard inoculation dose of 0.2 ml virus containing 1000 pock forming units ml-1 was injected via the chorioallantoic membrane (CAM) into the 11-day-old embryos that were subsequently hatched. The sensitivity of the two indigenous breeds was compared with the highly susceptible exotic White Leghorn (WL) strain maintained in the laboratory. The Kadaknath breed was about three-fold and Assel, about six-fold less sensitive than the WL strain, indicating superiority of the indigenous breeds over the exotic breed of fowl. Most of the CAM-susceptible chicks died of liver tumour (LT) and most of the CAM-resistant chicks survived. However, conversely associated tumour phenotype subclass chicks, i.e. CAM-susceptible LT-negative chicks that survived and CAM-resistant LT-positive chicks that died, occurred consistently in the three breeds of fowl. Nevertheless, the overall survival potential of Kadaknath chicks measured up to 8 weeks post-hatching was greater than that of Aseel chicks. Neither transformation of embryonic tissue prior to hatching nor the visceral metastasis including liver conformed with the degree of CAM-infection as measured by number of pocks on CAMs.

Systemic sclerosis stimulates angiogenesis in the chick embryo chorioallantoic membrane.

Skin biopsies from patients with systemic sclerosis (SSc) were investigated for their angiogenic activity by using the chick embryo chorioallantoic membrane (CAM) assay. Ten samples of SSc and 10 of normal skin from age- and sex-matched subjects were grafted onto the CAM, and the angiogenic response in pathological and control implants was assessed on histological sections by a planimetric point-count method 4 days after grafting. The vascular counts in the area underlying the SSc were significantly higher than those of normal skin and a dense mononuclear cell infiltrate was detectable around the blood vessels in pathological specimens. These results suggest that SSc may promote angiogenesis, perhaps leading to the release of several angiogenic factors. Moreover, the role played in the angiogenic response by the inflammatory cells forming the cellular infiltrate is suggested by this study.

Infectious bronchitis agar-gel precipitin test--use of infected allantoic fluid as antigen.

The use of infected allantoic fluid (AF) as precipitating infectious bronchitis (IB) antigen was investigated. The results show that unconcentrated AF harvested at the right time can be a very satisfactory precipitating IB antigen. With the majority of the virus strains used, unconcentrated AF, harvested 68 hours postinoculation (PI), showed more precipitating activity than that harvested at 20 or 120 hours PI. If further antigen concentration is required, dialysis with polyethyleneglycol MW 20,000, freeze-drying, and precipitation with polyethyleneglycol 6,000 are satisfactory methods of concentration.

ELISA test for the detection of influenza H7 antibodies in avian sera.

Using a monoclonal antibody (MAb) specific for the H7 influenza surface glycoproteins, a serological enzyme-linked immunosorbent assay (ELISA) test has been developed. This MAb was made using the low-pathogenicity (LP) avian influenza (AI) strain (BS2676/99) isolated in Italy during a recent outbreak. The test is able to detect H7 antibodies in avian sera. The H7 ELISA has a 99% concordance of results with the classical hemagglutination inhibition (HI) test.

Effect of in ovo vaccine delivery route on herpesvirus of turkeys/SB-1 efficacy and viremia.

A study was designed to ascertain the influence of in ovo site of inoculation and embryonic fluid type on the development of Marek's disease (MD) vaccine viremia and efficacy against MD challenge. The experiments were divided into in vitro and in vivo phases. In the in vitro phase, herpesvirus of turkeys/SB-1 vaccine was combined with basal medium eagle (BME) medium (control), amniotic fluid, or allantoic fluid and subsequently titrated on secondary chick embryo fibroblast cultures. There were no significant differences in titer between the virus inoculum carried in BME and the virus inoculum combined with either the allantoic fluid or the amniotic fluid. In the in vivo phase, five routes of inoculation, amniotic, intraembryonic, allantoic, air cell, and subcutaneous at hatch, were compared for generation of protection against virulent MD challenge. Comparisons were made in both specific-pathogen-free and commercial broiler embryos/chicks and, for the amniotic and allantoic routes, injection at either day 17 or day 18 of embryonation. Reisolation of the vaccine virus at day 3 of age was also done for all routes with the exception of the air cell route. Vaccine virus was recovered from all birds tested that were injected in ovo via the amniotic and intraembryonic routes and the subcutaneously at hatch route but was isolated only sporadically from birds inoculated via the allantoic route. Vaccination protective efficacy against virulent MD for all birds vaccinated in ovo via the amniotic or intraembryonic routes and birds vaccinated subcutaneously at hatch was over 90% regardless of day of in ovo injection or bird type. Protective efficacy for vaccines delivered in ovo by either the allantoic or the air cell routes was less than 50% regardless of day of injection or bird type. Therefore, in ovo MD vaccines must be injected either via the amniotic route or the intraembryonic route for optimal performance.

Comparison of agar-gel precipitin responses among strains of fowl adenovirus using antigens prepared from chorioallantoic membranes and chicken kidney cell cultures.

Agar-gel precipitin responses obtained for serologically different strains of fowl adenovirus (FAV) in tests using antigens prepared from FAV-infected chorioallantoic membranes (CAM antigen) and chicken kidney cell cultures (CKC antigen) were compared. Findings showed that both types of antigens exhibited less sensitivity to heterologous than to homologous antisera and that quantitative differences in sensitivity were present between serotypes. CAM antigens were more sensitive than CKC antigens to heterologous antisera. Polyvalent CAM antigens containing 2 or 3 antigens increased sensitivity in testing of field serum samples, resulting in a higher rate of detection.

Effects of 6-Hydroxydopamine on the antibody response to the hapten dinitrophenyl in the chicken.

Antibody responses to the hapten dinitrophenyl (DNP) and the concentration of catecholamine in chickens received a single injection of 6-Hydroxydopamine (6-OHDA) into the chorioallantoic cavity at the embryonal stage were evaluated. A significantly enhanced anti-DNP IgA response and a markedly decreased level of noradrenaline in the peripheral blood were observed in chickens treated with 400 micrograms of 6-OHDA at 14 days of incubation. These results suggested the immunomodulatory influence of the sympathetic nervous system.

[Improved methods of controlling the purity and activity of inactivated influenza vaccines]. / Sovershenstvovanie metodov kontrolia chistoty i aktivnosti inaktivirovannykh grippoznykh vaktsin.

Rooster monospecific sera to influenza virus hemagglutinin free from antibodies to the host (chick embryo) admixture components were prepared and satisfactorily used in radial immunodiffusion test for control of the levels of hemagglutinin in influenza vaccines. The indirect hemagglutination test with erythrocytic antibody diagnosticum has been proposed for the detection of low ovalbumin concentrations. The sensitivity of this method is less than 0.003 micrograms/ml ovalbumin which significantly surpasses other currently accepted methods for control of this component in inactivated influenza vaccines. Immunochemical methods established the presence in influenza vaccines of other "nonovalbumin" multicomponent admixtures. Their sensitizing activity was characterized and found to be 4-5 times weaker than that of ovalbumin.

[Sensitizing action of nonvirion admixtures in inactivated influenza vaccines in an experiment]. / Izuchenie sensibiliziruiushchego deistviia nevirionnykh primesei v inaktivirovannykh grippoznykh vaktsinakh v éksperimente.

The side-effect of nonvirion admixtures in inactivated influenza vaccines has been experimentally studied. The minimal sensitizing dose of allantoic admixtures other than ovalbumin has been experimentally determined in vivo. This dose has proved to be 4 times higher than the sensitizing dose of ovalbumin. The presence of sharply defined correlations between the concentration of the admixtures contained in inactivated influenza vaccines, the titers of antibodies to these admixtures and the severity of anaphylactic reactions has been established in guinea pigs after their multiple immunization.

[Analysis of the immunochemical purity of modern influenza vaccines]. / Analiz immunokhimicheskoi chistoty sovremennykh grippoznykh vaktsin.

Corpuscular influenza vaccines have been found to contain chick embryo antigens differing from ovalbumin in their antigenic, immunogenic, and allergenic properties. The study has revealed that host antigens are present in vaccines in the form of free contaminants and as substances incorporated into viruses. The vaccine prepared by the method of sorption-elution on red blood cells with subsequent gel chromatography is characterized by the highest antigenic purity.

[The use of the immunoperoxidase test with monoclonal antibodies for detecting influenza A viruses]. / Ispol'zovanie immunoperoksidaznogo testa s monoklonal'nymi antitelami dlia vyiavleniia virusov grippa A.

The immunoperoxidase test was used to detect influenza virus in cells of a chorionallanthois shell of infected chicken embryos. Application of monoclonal antibodies D8 and A11 in the analysis has permitted detecting reproduction of type A (subtypes H1N1, H2N2, H3N2) viruses, the PGA titre of the respective allantois liquids being not lower than 1:16. The matrix protein and hemagglutinin, detection of which underlies this analysis, were found on the cell membrane, in the perinucleus region and as cytoplasmic inclusions.

Derivation and characterization of progenitor stem cells from canine allantois and amniotic fluids at the third trimester of gestation.

Fetal tissues are frequently discarded before (amniocentesis) or after birth, which both facilitates stem cell access and helps to overcome ethical concerns. In the present study, we aimed to isolate and characterize stem cells from the allantoic and amniotic fluids (ALF; AMF) of third trimester canine fetuses. This gestation age has not been previously explored for stem cells isolation. The gestational age, cell culture conditions and method of isolation used in this study allowed for the establishment and efficient expansion of ALF and AMF cells. We showed that the majority of ALF and ALF cells express the stem cell markers, such as vimentin, nestin and cytokeratin 18 (CK18). Under appropriate culture conditions AMF derived cells can undergo differentiation into osteogenic, adipogenic, chondrogenic and neuron-like lineages. ALF derived cells showed adipogenic, and chondrogenic potential. Therefore, ALF and AMF cells derived at the third gestation trimester can be qualified as progenitor stem cells, accordingly referred as (alantoic fluid progenitor/stem) ALF PS cells and (amniotic fluid progenitor/stem) AMF PS cells.

Amniotic and allantoic fluids from experimentally infected sheep contain immunoglobulin specific for Chlamydophila abortus.

Chlamydophila abortus, the aetiological agent of enzootic abortion of ewes (EAE), replicates in trophoblast cells leading to their destruction and dissemination of the bacterium to foetal organs. To further understand the pathogenesis of EAE, amniotic and allantoic fluids were collected from experimentally infected pregnant ewes at 30 (7 samples from each fluid), 35 (8 samples from each fluid), 40 (10 samples from each fluid) and 43 (6 amniotic fluids and 7 allantoic fluids) days post-infection to determine pathogen numbers and other markers of infection. Whilst experimentally infected ewes had characteristic placental lesions, only two amniotic and seven allantoic fluid samples were positive for C. abortus by real-time PCR. In contrast, all amniotic and allantoic fluids were positive for immunoglobulin. Immunoglobulins were generally detected earlier in allantoic fluid than in amniotic fluid and the numbers of samples containing immunoglobulins increased as infection progressed. IgG in amniotic and allantoic fluids was shown to be specific for C. abortus, and reacted with the major outer membrane proteins, polymorphic outer membrane protein and macrophage infectivity potentiator protein. A comparison of two-dimensional immunoblots using purified IgG from the allantoic fluid, amniotic fluid, ewe serum and foetal serum of a C. abortus infected animal at 40 days post infection indicated a pattern of reactivity intermediate between that of the ewe serum and the foetal serum. Results suggest that a maternal source of immunoglobulin is predominant at 30 days post-infection but that foetal derived antibodies may be contributed at a later stage.

Antibodies against allantoic fluid of chick embryos detected in Japanese sera.

Japanese sera were shown by enzyme-linked immunosorbent assay (ELISA) to contain frequently antibodies against allantoic fluid, confirming the results obtained in our previous study on ELISA for the detection of mumps antibodies. Chromatographic analysis with Sephacryl S-300 of the allantoic fluid antigen used for ELISA suggested the antigens for these antibodies in Japanese sera to be macromolecular proteins. Comparative absorption tests with allantoic fluid and ovomacroglobulin were therefore carried out on serum samples positive in ELISA with allantoic fluid antigen, and ovomacroglobulin was identified to be the antigenic component for antibodies to allantoic fluid antigen in Japanese sera.

Expression of major histocompatibility complex (MHC) antigens on horse trophoblast.

Antibodies to fetal major histocompatibility complex (MHC) antigens are routinely detected in the serum of pregnant mares some 2-4 weeks after formation of the endometrial cups at Day 36-38 after ovulation. Several experimental approaches were taken to determine whether paternal MHC antigens are expressed on horse placental tissues. First, absorption of anti-paternal MHC antisera with a large volume of endometrial cup cells removed antibody activity in only 2 of 4 experiments. Second, repeated immunization of horses with endometrial cup tissue recovered from a mare on Day 47 of pregnancy failed to induce the formation of anti-MHC antibodies. Third, a potent anti-MHC antiserum, raised in a pregnant mare which had previously received skin grafts from the MHC homozygous mating stallion, labelled chorionic girdle, but not normal allantochorion, when tested in an indirect immunoperoxidase labelling assay on tissues bearing the MHC antigens of the stallion. These results indicate that the rapidly dividing cells of the chorionic girdle, the progenitor tissue of the equine endometrial cups, express high levels of paternal MHC antigen, and may serve as the alloantigenic stimulus for cytotoxic antibody production by pregnant mares. Conversely, the mature, CG-secreting endometrial cup cells have a much reduced expression of paternal MHC antigen.

Anti-influenza antibody assay by light scattering.

A physical method based on light scattering at 90 degrees was used to make evident the specific interaction between influenza virus and influenza antiserum. Purified virus put in contact with different dilutions of normal chicken serum exhibited a dose-effect dependence, which was significantly different from that corresponding to the virus-antiserum interaction. The maximum dilution of anti-influenza rabbit serum allowing the detection of the specific interaction between serum and infected allantoic fluid was then established. This value was considered to represent the "light scattering titer" of the antiserum.