Sugar chain-recognizing antibodies and remedies for HIV infectious diseases

#The present invention relates to novel sugar-chain-recognizing antibodies, and more particularly to antibodies which belong to the class IgM and which recognize sugar chains expressed in HIV-infected cells, as well as to remedies for treating HIV-patients containing the antibodies as effective ingredients.

#AIDS (acquired immunodeficiency syndrome) was first discovered in San Francisco in 1981 as a fatal immunodeficiency disease of homosexual males (Gottlieb, M. S., Schroff, R., et al., N. Engl. J. Med., 305, 1425-1430(1981)). Two years later, the Montanie group of the Pasteur Institute in France discovered the virus that causes AIDS (Barre-Sinoussi, F., Chermann, J. C., et al., Science, 220, 868-871(1983)). In 1985, this virus was univocally named HIV (human immunodeficiency virus) (Coffin, J., Haase, A., et al., Science, 232, 697(1986)).

#AIDS is a disease having the following features and effects: When an individual is infected with HIV through sexual intercourse, blood transfusion, etc., the virus destroys the immunological functions of the infected individual, causing acquired immunodeficiency of the host, i.e., the infected individual. Eventually, the host manifests a variety of symptoms such as diarrhea and pneumonia, resulting in a final outcome of death of the host.

#FIG. 1 is a graph showing the results of an epitope analysis performed on serum sample No. 1.

#FIG. 2 is a graph showing the results of an epitope analysis performed on serum sample No. 56.

#FIG. 3 is a graph showing the cytolysis capacity of HIV-infected-MOLT4 cells by human serum containing the IgM from individual who is a healthy HIV seronegative donor.

#As used herein, sugar chains are represented by customary abbreviations in the art; Gg stands for ganglio, Cer for ceramid, Gal for galactose, GalNAc for N-acetylgalactose, and Glc for glucose. The antibodies of the present invention may be separated from human serum, or they may be prepared through a conventional method for raising antibodies using Gg4Cer or GM2 as the antigen, so long as the antibodies recognize Gg4Cer or GM2 (ganglioside GM2: II3αNeuAc-GgOse3Cer) and belong to the immunoglobulin class as IgM.

#In order to separate the antibodies of the present invention from human serum, these may be used ordinary methods for screening the presence of antibodies employing Gg4Cer or GM2 as an antigen. The serum may be one collected from sero negative HIV-infected patient or others derive from healthy individual. The antibody against Gg4Cer or GM2 may be obtained through a conventional method such as a hybridoma method or a method using EB virus immortalization.

#Techniques that may be use(for the screening include conventional ELISA, RIA, fluorescent antibody technique, dot-immunobinding assay, the Western blotting method, and the 51Cr-release method.