Effect of bovine lactoferrin on a transmissible AIDS-like disease in mice.

The effect of bovine lactoferrin (bLF) was examined on an AIDS-like disease (ALD) in mice. Induction of disease was achieved by inoculation with infected cell-free plasma from diseased mice to uninfected ones. The effect of treatment with bLF was investigated when administered simultaneously with the virus, 20 days prior to infection, or 20 days after infection.

Reactions of peripheral blood mononuclear cells (PBMC) of camels with monoclonal antibodies against ruminant leukocytes.

The particular immune system of the camel has been but little investigated. In this work circulating camel peripheral blood mononuclear cells (PBMC) were studied by flow cytometry. Monoclonal antibodies (mAbs) raised against ruminant leukocytes were used for the detection of cell surface antigens.

Cellular immune response cytokine expression during the initial stage of bovine leukemia virus (BLV) infection determines the disease progression to persistent lymphocytosis.

We have established experimental models of bovine leukemia virus (BLV) infection followed by progression to persistent lymphocytosis (PL) positive (BLV+PL+) or PL negative (BLV+PL-) stages of infection. Two out of six BLV infected animals developed PL+ 4 weeks after BLV infection. One other animal became PL+ late in the course of infection and three infected animals stayed PL-.

Experimental infection of calves with bovine leukemia virus (BLV): an applicable model of a retroviral infection.

An experimental model of chronic infection with bovine leukemia virus (BLV) was established in young calves within a relatively short time. In the sera of all infected calves, precipitating antibodies were detected within 5 weeks after infection but upon disease progression pattern of cellular profiles varied. Three calves exhibited transient lymphocytosis 3-5 weeks after infection, two became persistent lymphocytotic (PL+) by that time and one stayed non-lymphocytotic (PL-) for 11 weeks and became PL+ after 4.

Short-termed expression of interleukin-12 during experimental BLV infection may direct disease progression to persistent lymphocytosis.

In this study an attempt was made to elucidate cellular response cytokine expression upon experimental bovine leukemia virus (BLV) infection in cattle. Progression of infection was monitored by BLV gp51 mRNA expression or DNA amplification by RT-PCR or PCR, respectively, to detect provirus infected cells. Antibodies to BLV were detected by an agar gel immuno-diffusion (AGID) test in 5 weeks and persistent lymphocytosis (PL+) was established in all four BLV-infected animals in 24 weeks after infection.

Effect of permeabilization on peripheral blood lymphocytes of bovine leukemia virus (BLV)-infected cattle.

Cell surface proteins serve as markers for immunophenotypic characterization of lymphocyte subsets by appropriate monoclonal antibodies and fluorescence-activated cell sorter (FACS) analysis. By the same method, internal antigens or those that are only partially expressed on the cell surface can be determined after permeabilization of the cells. Peripheral blood lymphocytes obtained from bovine leukemia virus (BLV)-infected cattle and from BLV-free cattle were permeabilized and several lymphocyte populations were examined.

Detrimental effect of bovine leukemia virus (BLV) on the immunological state of cattle.

Bovine leukemia virus (BLV) is a retrovirus which seems to affect both the humoral and the cellular immune response. Cows affected by enzootic bovine leukemia (EBL) showed a reduction of IgM-producing cells in the spleen and lymph nodes. Experimentally infected calves had lower levels of secretory IgM and a decrease in T lymphocytes in the peripheral blood.

gamma delta T-lymphocytes and anti-heat shock protein reactivity in bovine leukemia virus infected cattle.

Bovine leukemia virus (BLV) induces a chronic infection in cattle that may result in persistent lymphocytosis (PL) and, sometimes, enzootic bovine leukosis. The cellular and humoral immune responses of the host following infection have been extensively investigated but little is known about the involvement of gamma delta T-cells in BLV pathogenesis. The affluence of these cells in cattle, and particularly in the peripheral blood of young ruminants, may suggest a particular role for them in defense mechanisms.

Circulating immune complexes in bovine leukemia virus (BLV)-infected cattle.

Circulating immune complexes (ICs) were detected in the sera of bovine leukemia virus (BLV)-seropositive cattle. Immune complexes were precipitated in 2.5% polyethylene glycol (PEG) and further dissociated.

A lactogenic-immune-deficiency-syndrome in cows: unexplained phenomenon.

The majority of adult cows in a certain dairy herd, were found to have very low levels of immunoglobulins (Igs) in their colostrum. This phenomenon was defined by us as Lactogenic-Immune-Deficiency-Syndrome (LIDS). The mean IgG levels were 44.

IgM rheumatoid factor in cattle immunized against babesiosis.

Polyclonal bovine IgM-rheumatoid factors (IgM-RFs) were examined in sera of cattle immunized against babesiosis. An enzyme-linked immunosorbent assay (ELISA) was used enabling rapid screening of serum samples. Results obtained indicate a rise of serum IgM-RF levels with age in healthy bovines.

Immunoglobulin M (IgM) indirect enzyme-linked immunosorbent assay and the involvement of IgM-rheumatoid factor in the serodiagnosis of BHV-1 infection.

An IgM enzyme-linked immunosorbent assay (IgM-ELISA) for the detection of antibodies to bovine herpesvirus-1 (BHV-1) was developed. Its applicability was examined by serological studies in two calves experimentally infected with virulent BHV-1 over a period of 60 days. IgM antibodies were detected by ELISA on day 6 after infection, and there was an increase in IgG antibodies on day 9.

An enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies to Anaplasma centrale and Anaplasma marginale.

An enzyme-linked immunoassay (ELISA) was applied to detect antibodies to A. centrale and A. marginale using homologous and heterologous antigens.

Immunogenicity and allergenicity of Culicoides imicola (Diptera: Ceratopogonidae) extracts.

Summer seasonal recurrent dermatitis (SSRD) or "sweet itch" is a seasonally occurring allergic dermatitis of horses provoked by biting midges. The allergic skin reactions have been attributed to allergens present in various Culicoides species. C.

Identification and partial purification of soluble antigens from culture-grown Besnoitia besnoiti endozoites.

Soluble antigens from culture-grown Besnoitia besnoiti endozoites were identified following their partial purification by affinity chromatography. A specific eluate obtained after affinity chromatography on a column to which antibodies from serum of a naturally infected cow were bound exhibited seven polypeptide bands on sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE). Five bands were observed in the eluate from an immunoadsorbent to which antibodies from an experimentally infected calf were coupled.

Soluble antigens from culture-grown Besnoitia besnoiti endozoites.

Soluble antigens from Besnoitia besnoiti cell culture-grown endozoites, obtained either by hypotonic lysis or by freeze-thawing and ultrasonication (FTS) of the organisms, were detected by the agar gel immunodiffusion method. Each antigenic preparation yielded 1-4 precipitin lines when reacted with the corresponding rabbit hyperimmune serum, while no reaction was observed with Besnoitia-positive sera from naturally infected cattle. Soluble exoantigens released by viable Besnoitia endozoites into the supernatant of infected cell cultures formed two precipitin lines with rabbit anti-FTS hyperimmune serum and appeared as positively charged protein in immunoelectrophoresis.

ELISA test for the serodiagnosis of Akabane virus infection in cattle.

A simple ELISA test has been developed for the detection of IgG and IgM antibodies to Akabane virus in bovine serum. The test is specific and its sensitivity higher than the serum neutralisation assay. Detection of IgM antibodies can serve as a rapid method of diagnosing primary infection with Akabane virus.

Reactivity of IgM-rheumatoid factors of human, feline and bovine sera.

The reactions of IgM-rheumatoid factors (IgM-RFs) from human, feline and bovine sera were examined with their homologous monomeric IgGs and with IgGs of other species. Cross-reactivities with IgGs of other species were observed in each separate system. By the use of an enzyme-linked immunosorbent assay (ELISA), measurable differences in reactivities were obtained.

Humoral immune response of asymptomatic cats naturally infected with feline leukemia virus.

The humoral immune response of cats that were naturally infected with the feline leukemia virus (FeLV) was examined after antigenic stimulation with the synthetic antigen poly(L-Tyr, L-Glu)-poly(DL-Ala)-poly(L-Lys). The primary humoral antibody response in FeLV-infected cats was both delayed and greatly reduced, compared with that seen in uninfected control cats. A similar discordance was observed after secondary stimulation with the antigen, in the FeLV-infected cats had both a delayed response and a reduced response, compared with uninfected cats.

Rheumatoid factors in natural retrovirus infections of the cat and cattle.

The occurrence of IgM-rheumatoid factors (RFs) was investigated in natural retrovirus infection of cats with feline leukaemia virus and of cattle with bovine leukaemia virus. IgM-RFs of polyclonal character were detected. No significant differences were observed between the amounts of IgM-RFs in the retrovirus-infected animals and their respective controls.

Specific antibodies to Besnoitia besnoiti precipitated from serum of cattle by live parasites and by soluble antigen.

Specific precipitable antibodies of both IgG and IgM classes were detected in sera of cattle naturally infected with B. besnoiti. The amount of specific antibodies of the IgG class precipitated by soluble antigen was in the range of 17-50 micrograms/ml serum while that of the IgM class ranged between 5 and 24 micrograms/ml serum.

Enzyme linked immunosorbent assay for detection of antibodies against Besnoitia besnoiti in cattle.

The use of the ELISA method for the detection of antibodies to B. besnoiti in cattle is described and compared to the IFAT technique. One hundred and twenty-one sera were examined, of which 61 were sera of calves experimentally infected with B.

Use of a synthetic antigen to predetermine the responsiveness of cattle to vaccine-induced immunity.

Groups of healthy, virus-infected and leukaemic cattle were injected with synthetic multichain poly(Tyr, Glu)-poly(Ala)--poly(Lys) in order to predetermine responsiveness to vaccine-induced immunity. Immunospecific purification of antibodies, precipitin reactions and enzyme linked immunosorbent assay (ELISA) tests were carried out on sera collected at various intervals after immunization. Of the methods employed, the ELISA had the advantage of specificity, sensitivity and speed for screening the humoral immune response of cattle to antigenic stimulation.

Epidemiological and immunological studies of sweet itch in horses in Israel.

A survey of sweet itch in horses in Israel based on a questionnaire to owners reported that 158 of 723 horses (21.8 per cent) had sweet itch lesions. The results indicated that the likelihood of a horse acquiring sweet itch decreased with increasing altitude but no definite association with rainfall zones was evident.