A monoclonal antibody recognizing a determinant shared by HLA-A2 and HLA-Aw69 (A28* variant)

Conservation of HLA class I private epitopes in macaques

Fifty mouse monoclonal antibodies (mAb) specific for HLA class I epitopes were compared for their reactivity against two closely related nonhuman primate species, pigtailed macaques (Macaca nemestrina, Mn) and longtailed macaques (M. fascicularis, Mfl), which diverged from the hominoids 23-40 million years ago. An analysis of Nei's genetic identity (I) and distance (D) based on reactivity of all class I-specific mAb showed, as expected, that the macaques are more closely related to each other (I = 0.959) than to man (I = 0.782 for Mn and 0.859 for Mfl). However, there were clear differences in genetic similarity with respect to certain epitopes. Macaques were most different from each other and from man in expression of heterologous epitopes recognized by the mouse that are not polymorphic among humans. In contrast, the most polymorphic epitopes unique to single HLA alleles, so-called private epitopes, were present in all the species, and neither macaque species could be distinguished from humans, suggesting that certain class I private epitopes may be highly conserved in evolution.

Reactivity of anti-HLA class I polymorphic monoclonal antibodies with normal human skin

In this work the reactivity of 16 monoclonal antibodies raised against different HLA class I specificities was tested with human skin of healthy donors of known HLA typing. By indirect immunofluorescence, six antibodies reacted strongly with keratinocytes carrying the corresponding alloantigens. The reactivity of 3 other antibodies which was weak or absent using indirect immunofluorescence, was enhanced by various amplification systems such as avidin-biotin-peroxidase method, biotin-streptavidin-fluorescein complex and especially preliminary trypsin treatment that revealed alloantigens masked in the epidermis. The immunostaining of 4 antibodies was negative regardless of the method used. Some of the antibodies we tested cross-reacted with cytoplasmic antigens of keratinocytes. This study has allowed to select a battery of monoclonal antibodies which can specifically detect alloantigens on keratinocytes and will be useful for the recognition the cell origin in allografting experiments.

New HLA-A2 variants defined by monoclonal antibodies and cytotoxic T lymphocytes

Three HLA-A2 variants, A2-DW, A2-KC, and A2-Lee, were identified in three Chinese donors using a panel of monoclonal antibodies. A2-DW was negative with two of the ten HLA-A2 monoclonal antibodies tested, whereas A2-KC was negative with five of the ten and A-2 Lee was negative with one. Epstein-Barr virus-specific cytotoxic T cells generated from the A2-DW donor recognized and killed target cells prepared from the A2-KC donor, but did not recognize target cells from HLA-A2.1, -A2.2, or -A2.4 donors. In isoelectric focusing studies, A2-DW and A2-KC focus in identical positions more acidic than the other HLA-A2 antigens tested.

Generation and characterization of three new monoclonal antibodies detecting the allospecificities HLA-A2,w69, HLA-A3 and HLA-B13

Immunization of balb/c mice with peripheral blood mononuclear cells of a leukemic patient possessing the antigens HLA-A2,3; B7,35 resulted in the polymorphic monoclonal antibody (moab) UL-101/68 (IgM) defining HLA-A3. Immunization of a second group of balb/c mice with the lymphoblastoid cell line BER homozygous for HLA-A2; B13 revealed two polymorphic moabs UL-39/10 (IgG3) specific for HLA-B13 and UL-39/24 (IgG2b) defining HLA-A2,w69. Immunoprecipitation and polyacrylamide gel electrophoresis with the two moabs of the IgG isotype confirmed the class I structure of the recognized antigens.