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Biomedical subjects

J Cronier

Publications and source records attributed to J Cronier.

9 recordsLinked to original sources
PubMed1998

Partial protection by vaccination with recombinant feline immunodeficiency virus surface glycoproteins.

In an effort to induce a strong immune response that might protect against feline immunodeficiency virus (FIV) challenge infection, three groups of five specified pathogen-free (spf) cats each were immunized subcutaneously with different FIV antigen preparations. Immunizations were done at weeks 0, 2, and 4 with 100 microg of recombinant SU from an FIV Zurich 2 (FIV Z2) strain expressed by E. coli (group 1) or the baculovirus expression system (groups 2 and 3) adsorbed on aluminum hydroxyde and administered with QS-21 (groups 1 and 2) or Freund's adjuvant together with the recombinant nucleocapsid protein (protein NC) of rabies virus (group 3). Protein NC was described to act as an exogenous superantigen. Group 3 cats demonstrated the highest detectable antibody response to the vaccine antigen as determined by ELISA and Western blot analysis. All immunized cats together with seven control animals were challenged with 20 CID50 of cat lymphocyte-grown FIV Z2 3 weeks following the last immunization. Whereas virus was readily recovered from peripheral blood lymphocytes of seven of seven nonvaccinated control cats following this challenge dose, virus was not recovered from two cats of groups 1 and 2. All cats in groups 2 and 3 showed a provirus load significantly decreased to 3% of that of controls up to week 8 after challenge infection. Eleven of 15 vaccinated cats and 5 of 7 control cats developed virus-neutralizing antibodies by week 8 after challenge infection. The two cats negative on virus isolation remained seronegative, developed no detectable virus-neutralizing activities, but were repeatedly positive in provirus PCR. Moreover, starting at week 1 after challenge, both cats showed the lowest provirus load in their respective groups. These results indicate that immunization with recombinant FIV SU in conjunction with appropriate adjuvants may lead to partial protection against FIV challenge infection.

Adjuvants, Immunologic↗
PubMed1994

[Vaccination of cats against infection with feline leukemia virus (FeLV): first recombinant vaccine and the effect of a pre-existing infection with feline immunodeficiency virus (FIV)].

A new recombinant FeLV vaccine was evaluated in 30 specified pathogen-free cats 10 months of age cats. The vaccine consisted of the non-glycosylated FeLV envelope protein p45, aluminium hydroxide and a saponin adjuvant. The cats (n = 18) were vaccinated twice intramuscularly, 3 weeks apart. All animals were challenged intraperitoneally with FeLV subgroup A, 18 weeks later. While 94% of the vaccinated cats showed no viraemia or were only transiently viraemic, 80% of the non-vaccinated animals became persistently viraemic within 2 to 3 weeks. In our hands the preventable fraction of the vaccine was 93%. In order to determine the effect of a pre-existing infection with feline immunodeficiency virus on the efficacy of vaccination, 50% of the cats were previously infected with FIV. The infected cats were protected to the same degree as the non-infected animals. With prolonged duration of FIV infection the probability increases, that the immune system of the cat will fail and clinical signs will appear. In order to observe a state of possible immunodeficiency, an accurate clinical examination of every cat prior to vaccination seems of major importance.

Animals↗
PubMed1991

Vaccination of cats experimentally infected with feline immunodeficiency virus, using a recombinant feline leukemia virus vaccine.

A group of 15 cats experimentally infected with a Swiss isolate of feline immunodeficiency virus (FIV) and a group of 15 FIV-negative control cats were inoculated with an FeLV vaccine containing recombinant FeLV-envelope. High ELISA antibody titer developed after vaccination in FIV-positive and FIV-negative cats. Vaccinated and nonvaccinated controls were later challenge exposed by intraperitoneal administration of virulent FeLV subtype A (Glasgow). Although 12 of 12 nonvaccinated controls became infected with FeLV (10 persistently, 2 transiently), only 1 of 18 vaccinated (9 FIV positive, 9 FIV negative) cats had persistent and 2 of 18 had transient viremia. From these data and other observations, 2 conclusions were drawn: In the early phase of FIV infection, the immune system is not depressed appreciably, and therefore, cats may be successfully immunized; a recombinant FeLV vaccine was efficacious in protecting cats against intraperitoneal challenge exposure with FeLV.

Animals↗
PubMed1991

Genetically-engineered subunit vaccine against feline leukaemia virus: protective immune response in cats.

A recombinant retroviral subunit vaccine has been developed that successfully protects cats from infectious feline leukaemia virus (FeLV) challenge. The antigen used is a non-glycosylated protein derived from the envelope glycoprotein of FeLV subgroup A, expressed in Escherichia coli. This recombinant protein, rgp70D, includes the entire exterior envelope protein gp70, plus the first 34 amino acids from the transmembrane protein p15E. The vaccine consists of purified rgp70D absorbed on to aluminium hydroxide and used in conjunction with a novel saponin adjuvant. Cats immunized with this formulation developed a strong humoral immune response, including neutralizing and feline oncornavirus-associated cell membrane antigen antibodies. Vaccinated animals showed an anamnestic response upon intraperitoneal challenge with FeLV-A, and were protected from viral infection. In contrast, the control animals developed viraemia shortly after the challenge, which in most cases became chronic. Formulation of the same antigen with other widely used adjuvants elicited poor protective immune responses in cats.

Adjuvants, Immunologic↗
PubMedDate not supplied

[Bone lesions in micromegakaryoblastic leukemia].

The authors report four cases of skeletal lesions associated with acute megakaryoblastic leukemia. In this particular form of the disease, the periostal appositions are more frequent and more severe than in other types of acute leukemia. A very marked osteolysis with true metaphyseal lacunar zones are also observed. These particular types of bone lesion are related to the especially widespread cellular proliferation in megakaryoblastic leukemia, and their occurrence implies a very bad prognosis.

Bone and Bones↗