Biomedical subjects

B Lisowska-Grospierre

Publications and source records attributed to B Lisowska-Grospierre.

39 records · Page 3Linked to original sources

PubMedDate not supplied

Immune response to Toxoplasma gondii in man. I. Common idiotypic determinants of toxoplasma-specific human antibodies.

A rabbit antiserum against human anti-toxoplasma antibodies was prepared. The rabbit antiserum was made antiidiotypic by extensive absorption. It bound 70% of radio-labelled autologous antibodies. The same antiidiotypic antiserum bound to varying degrees, three out of four other anti-toxoplasma antibodies isolated from different individuals. Inhibition experiments, using 24 human sera containing varying amounts of antibodies, showed that about 60% of them cross-reacted with the antiidiotypic antiserum, indicating that some common determinants were present on human anti-toxoplasma antibodies. F(ab')2 fragments of antiidiotypic immunoglobulin revealed about 8% idiotype-positive (id+) cells among toxoplasma-induced blasts obtained from toxoplasma-sensitized normal donors.

Animals↗

PubMedDate not supplied

Antibody levels to Candida albicans carbohydrate and major cytoplasmic antigens isolated from standard and patient strains.

A solid phase radioimmunoassay (RIA) and ELISA were used to detect human antibodies to Candida albicans (CA) organisms or purified fractions, namely, carbohydrate-rich fraction (CRF) and cytoplasmic peptides (SSF) of CA. IgG antibodies to either whole organisms or to CRF were found in sera obtained from patients with chronic mucocutaneous candidiasis (CMCC) or digestive candidiasis, as well as in healthy control sera. In patient sera, no correlation between the clinical stage of disease and the IgG anti-CRF levels was found. In contrast, antibodies to SSF were absent in healthy control sera. IgM anti-SSF in the absence of IgG anti-SSF were found in sera of patients with recent digestive candidiasis, and low levels of IgM and IgG Ab were detected in sera of CMCC patients. The lack of correlation between IgG anti-CRF levels and clinical status can, in part, be explained by the individual variability of Candida strains and by the inadequacy of the laboratory standard antigens in the antibody assays used. The clinical relevance of different tests to detect anti-CA antibodies is discussed.

Animals↗

PubMedDate not supplied

A trans-acting class II regulatory gene unlinked to the MHC controls expression of HLA class II genes.

Class II (or Ia) antigens are highly polymorphic surface molecules which are essential for the cellular interactions involved in the immune response. In man, these antigens are encoded by a complex multigene family which is located in the major histocompatibility complex (MHC) and which comprises up to 12 distinct alpha- and beta-chain genes, coding for the HLA-DR, -DQ and -DP antigens. One form of congenital severe combined immunodeficiency (SCID) in man, which is generally lethal, is characterized by an absence of HLA-DR histocompatibility antigens on peripheral blood lymphocytes (HLA class II-deficient SCID). In these patients, as reported here, we have observed an absence of messenger RNA for the alpha- and beta-chains of HLA-DR, -DQ and -DP, indicating a global defect in the expression of all class II genes. Moreover, the lack of expression of HLA class II mRNAs could not be corrected by gamma-interferon, an inducer of class II gene expression in normal cells. Family studies have established that the genetic defect does not segregate with the MHC. We conclude, therefore, that the expression of the entire family of class II genes is normally controlled by a trans-acting class II regulatory gene which is unlinked to the MHC and which is affected in the patients. This gene controls a function or a product necessary for the action of gamma-interferon on class II genes.

Gene Expression Regulation↗