A Monoclonal Antibody to Lewis Y/Lewis b Revealing Mimicry of the Histone H1 to Carbohydrate Structures

Abstract

Antibodies to either peptide or carbohydrate tumour antigens are established tools for diagnostics and therapy. We here describe an antibody (A70‐A/A9) recognizing a carbohydrate epitope common to the tumour‐associated Lewis Y and Lewis b antigens (Fucα1‐2Galβ1‐4/3[Fucα1‐3/4]GlcNAcβ‐). Its specificity was established without doubt with a panel of 86 synthetic mono‐ and oligosaccharidic structures. This antibody was found to cross‐react with the nuclear protein histone H1. Binding to H1 was specific, periodate‐insensitive (non‐carbohydrate) and saturable. Histone H1 was able to inhibit Lewis Y binding very effectively in a concentration‐dependent manner. We conclude that it represents an example of natural peptide mimicry of a carbohydrate epitope. It may explain the observed occurrence of ‘anti‐histone autoantibodies’ in cancer patients.

High-throughput carbohydrate microarray profiling of 27 antibodies demonstrates widespread specificity problems

“…This antibody is listed as binding blood group H2, Le y , and Fuca1-2Galb1-3[Fuca1-4)GlcNacb1-3Galb1-4Glcb-BSA (Le b ) by the manufacturer. In contrast, a recent report showed strong binding to Le y , 30-fold weaker binding to Le b , and no binding to blood group H2 (Christensen et al 2007). Antibodies B376 (also known as A63-D/B12) and B393 (also known as A46-B/ B10) from Biomeda (Foster City, CA) did not show any binding on the array.…”

ANTI-HISTONE H1 IgGs POSSESS PROLIFERATIVE ACTIVITY TOWARDS HUMAN T-LEUKAEMIA CEM CELLS

“…The appearance of the anti-histone H1 IgGs in blood serum can be related to a phenomenon of the molecular mimicry of some self and foreign antigens [12]. An existence of the polyclonal and monoclonal Abs possessing cross-reactivity with histone H1 and other intracellular proteins and even with the carbohydrate antigens [15][16][17] might serve as a confirmation for such suggestion. However, the mechanisms responsible for the ability of the anti-histone H1 IgGs to stimulate cell proliferation are poorly understood yet.…”

Modifying Antibody Specificity by Chain Shuffling of VH / VL between Antibodies with Related Specificities

“…The binding patterns of the two MoAb were verified even at high antibody concentrations (50 μ g/ml) (data not shown). The fine specificities of the antibodies A70‐A/A9 and A46‐B/B10 were similarly analysed (published in Refs [29, 30]). Specificity data of all four antibodies are summarized in Table 1.…”

“…Antibody production. A70‐A/A9 (IgG1, κ) recognizing Lewis Y and partially Lewis b [29], A46‐B/B10 (IgM, κ) recognizing Lewis Y and H type 2 [30, 31] and A70‐C/C8 (IgM, κ) recognizing Lewis Y [31] have been published. A51‐B/A6 (IgA, κ) recognizing Lewis Y, H disaccharide and H type 2 was generated using a sequence of different glycoconjugates and MCF‐7 cells as immunogens.…”