Biomedical subjects

E S Song

Publications and source records attributed to E S Song.

22 records · Page 2Linked to original sources

PubMed1990

Rat and human natural killers exhibit contrasting immunoglobulin G subclass specificities in antibody-dependent cellular cytotoxicity reflecting differences in their Fc receptors (Fc gamma R).

Rat and human natural killers (rtNK and huNK, respectively) were compared in quantitative antibody-dependent cellular cytotoxicity (ADCC) assays for their capacity to recognize mouse and rat IgG monoclonal antibodies (MAb) of different subclasses. NK from these two species exhibit considerably different patterns of IgG subclass recognition as determined by the relative antibody concentrations required for comparable levels of target cells lysis. ADCC assays with a panel of 16 MAb revealed that the efficiency of rtNK-mediated target lysis diminished according to IgG subclass in the following order: molgG1 greater than rtlgG2a greater than molgG2b approximately molgG2a greater than rtlgG2b greater than molgG3. By comparison, huNK recognized the same antibodies with nearly the opposite order of efficiency: rtlgG2b much greater than molgG2a greater than molgG3 greater than molgG2b much greater than rtlgG2a approximately molgG1. Only molgG2a antibodies were equally potent with rtNK and huNK. The contrasting difference in IgG subclass recognition by rat and human NK reflects the comparatively low protein sequence homology between their respective IgG Fc receptors (Fc gamma R).

Animals↗

PubMed1989

The association of H-2Ld with human beta-2 microglobulin induces localized conformational changes in the alpha-1 and -2 superdomain.

We have analyzed changes in the antigenicity of major histocompatibility complex class I molecules resulting from the association of human beta-2 micro-globulin (B2m) with the mouse class I heavy chain. In particular, the H-2Ld molecule exhibited enhanced cross-reactivity for the 34-1-2 monoclonal antibody. In order to assess the nature of this structural alteration induced by human B2m, we utilized H-2 class I hybrid molecules in the mapping of the 34-1-2 determinant to the helical region of the alpha-1 domain. H-2Ld class I hybrid molecules were then used to establish the importance of the alpha-2 and -3 domains in the observed increase of 34-1-2 cross-reactivity following exchange with human B2m. The H-2Ld hybrids suggest that alterations in interdomain contact are responsible for enhanced 34-1-2 cross-reactivity on the H-2Ld molecule. It is likely that this alteration arises through changes in class I conformation at regions of the molecule distant from points of contact between B2m and the class I molecule. This suggests that perturbations induced by association of human B2m with H-2Ld can affect the conformation of the alpha-1 and -2 superdomain. That class I antigenic determinants are altered by the association of human B2m with mouse class I further suggests that the class I molecule is structurally flexible and may reflect the ability of the class I molecule to bind and present a vast array of disparate peptides to the T-cell receptor.

Amino Acid Sequence↗

PubMed1988

Allospecific cytotoxic T lymphocytes recognize an H-2 peptide in the context of a murine major histocompatibility complex class I molecule.

We have isolated cytotoxic T lymphocytes (CTL) preferentially reactive with the alpha 1 external domain of the H-2Ld antigen by selecting for T cells capable of recognizing a variant major histocompatibility complex (MHC) class I antigen sharing alpha 1 sequences with H-2Ld. Using these CTL, we demonstrate that a synthetic alpha 1 peptide corresponding to one of the helices derived from the H-2Ld molecule can be presented by a class I restriction element to reconstitute a CTL determinant borne by intact H-2Ld. Moreover, several other H-2L-reactive CTL generated independently were also able to recognize H-2Ld either as an intact alloantigen or as a peptide in conjunction with appropriate class I restriction elements. These data demonstrate that an H-2 peptide can reconstitute a CTL target structure and suggest that some alloreactive T cells in fact might be directed against allogeneic class I peptides in the context of a class I framework.

Amino Acid Sequence↗

PubMedDate not supplied

Adenoma malignum of uterine cervix in Peutz-Jeghers syndrome: CT and US features.

We report CT and ultrasound (US) features of adenoma malignum of the uterine cervix in a patient with Peutz-Jeghers syndrome (PJS) in whom bilateral ovarian mucinous cystadenomas and sex cord tumors with annular tubules were associated. Adenoma malignum was shown as a hyperechoic mass mixed with multiple cysts on US and a low attenuated endocervical mass on CT. We think that imaging demonstration of an endocervical mass is important for the correct diagnosis of adenoma malignum in a female with PJS.

Adenocarcinoma↗