Cd30 ligand

This application is a divisional of U.S. application Ser. No. 10/677,593, filed Oct. 2, 2003, now allowed; which is a divisional of U.S. application Ser. No. 09/628,126, filed Jul. 28, 2000, and issued as U.S. Pat. No. 6,667,039 on Dec. 23, 2003; which is a divisional of Ser. No. 09/079,785, filed May 15, 1998, and issued as U.S. Pat. No. 6,143,869 on Nov. 7, 2000; which is a divisional 08/580,014, filed Dec. 20, 1995, and issued as U.S. Pat. No. 5,753,203 on May 19, 1998; which is a divisional of Ser. No. 08/225,989, filed Apr. 12, 1994, and issued as U.S. Pat. No. 5,480,981 on Jan. 2, 1996; which is a continuation-in-part of U.S. application Ser. No. 07/966,775, filed Oct. 27, 1992, now abandoned; which is a continuation-in-part of U.S. application Ser. No. 07/907,224, filed Jul. 1, 1992, now abandoned; which is a continuation-in-part of U.S. application Ser. No. 07/899,660, filed Jun. 15, 1992, now abandoned; which is a continuation-in-part of U.S. application Ser. No. 07/892,459, filed Jun. 2, 1992, now abandoned; which is a continuation-in-part of U.S. application Ser. No. 07/889,717, filed May 26, 1992, now abandoned. Priority is also claimed from International Application PCT/US93/04926, filed May 25, 1993.

Hodgkin\'s Disease is a human lymphoma, the etiology of which is still not well understood. The neoplastic cells of Hodgkin\'s Disease are known as Hodgkin and Reed-Sternberg (H-RS) cells. CD30 is a 120 kd surface antigen widely used as a clinical marker for Hodgkin\'s lymphoma and related hematologic malignancies (Froese et al., J. Immunol. 139:2081 (1987); Pfreundschuh et al., Onkologie 12:30 (1989); Carde et al., Eur. J. Cancer 26:474 (1990)). Originally identified by the monoclonal antibody Ki-1, which is reactive with H-RS cells (Schwab et al., Nature (London) 299:65 (1982)), CD30 was subsequently shown to be expressed on a subset of non-Hodgkin\'s lymphomas (NHL), including Burkitt\'s lymphoma, as well as several virally-transformed lines (human T-Cell Lymphotrophic Virus I or II transformed T-cells, and Epstein-Barr Virus transformed B-cells (Stein et al., Blood 66:848 (1985); Andreesen et al., Blood 63:1299 (1984)). That CD30 plays a role in normal lymphoid interactions is suggested by its histological detection on a small population of lymphoid cells in reactive lymph nodes, and by induced expression on purified T- and B-cells following lectin activation (Stein et al., Int. J. Cancer 30:445 (1982) and Stein et al., 1985, supra).

CD30 expression has also been detected on various non-Hodgkin\'s lymphomas (NHL), such as large-cell anaplastic lymphomas (LCAL), cutaneous T-cell lymphomas, nodular small cleaved-cell lymphomas, lymphocytic lymphomas, peripheral T-cell lymphomas, Lennert\'s lymphomas, immunoblastic lymphomas, T-cell leukemia/lymphomas (ATLL), adult T-cell leukemia (T-ALL), and centroblastic/centrocytic (cb/cc) follicular lymphomas (Stein et al., Blood 66:848 (1985); Miettinen, Arch. Pathol. Lab. Med. 116:1197 (1992); Piris et al., Histopathology 17:211 (1990); Burns et al., Am. J. Clin. Pathol. 93:327 (1990); Piris et al., Histopathology 18:25 (1991); Eckert et al., Am. J. Dermatopathol. 11:345 (1989); Gianotti et al., Am. J. Dermatopathol. 13:503 (1991); Maeda et al., Br. J. Dermatol. 121:603 (1989)). The association of the CD30 antigen with lymphoid malignancies has proven to be a useful marker for the identification of malignant cells within lymphoid tissues, particularly lymph nodes. However, expression of CD30 has also been reported on a portion of embryonal carcinomas, nonembryonal carcinomas, malignant melanomas, mesenchymal tumors, and myeloid cell lines and macrophages at late stages of differentiation (Schwarting et al., Blood 74:1678 (1989); Pallesen et al., Am J. Pathol. 133:446 (1988); Mechtersheimer et al., Cancer 66:1732 (1990); Andreesen et al., Am. J. Pathol. 134:187 (1989)).

Cloning and expression of a gene encoding CD30 has been reported and CD30 has been characterized as a transmembrane protein that possesses substantial homology to the nerve growth factor receptor superfamily (Durkop et al., Cell 68:421, 1992). Durkop et al. suggest that CD30 is the receptor for one or more as yet unidentified growth factors, and recognize the importance of investigating the existence and nature of such growth factors in order to achieve insight into the etiology of Hodgkin\'s Disease.

Prior to the present invention, however, no such growth factors or other molecules that bind to the CD30 receptor were known. A need thus remained for identification and characterization of a ligand for CD30.

The present invention provides a novel cytokine designated CD30-L, as well as isolated DNA encoding CD30-L protein, expression vectors comprising the isolated DNA, and a method for producing CD30-L by cultivating host cells containing the expression vectors under conditions appropriate for expression of the CD30-L protein. CD30-L is a ligand that binds to the Hodgkin\'s disease-associated antigen CD30 (a cell surface receptor). Antibodies directed against the CD30-L protein or an immunogenic fragment thereof are also provided. Uses of CD30-L in diagnostic and therapeutic procedures are also disclosed.

cDNA encoding a novel polypeptide that can act as a ligand for the Hodgkin\'s Disease-associated receptor known as CD30 has been isolated in accordance with the present invention. Also provided are expression vectors comprising the CD30 ligand (CD30-L) cDNA and methods for producing recombinant CD30-L polypeptides by cultivating host cells containing the expression vectors under conditions appropriate for expression of CD30-L, and recovering the expressed CD30-L. Purified CD30-L protein is also encompassed by the present invention.

The present invention also provides CD30-L or antigenic fragments thereof that can act as immunogens to generate antibodies specific to the CD30-L immunogens. Monoclonal antibodies specific for CD30-L or antigenic fragments thereof thus can be prepared.

The novel cytokine disclosed herein is a ligand for CD30, a receptor that is a member of the TNF/NGF receptor superfamily. Therefore, CD30-L is likely to be responsible for transducing a biological signal via CD30, which is known to be expressed on the surface of Hodgkin\'s Disease tumor cells.

One use of the CD30 ligand of the present invention is as a research tool for studying the pathogenesis of Hodgkin\'s Disease. As described in examples 8 and 13, CD30-L enhances the proliferation of the CD30⁺ neoplastic Hodgkin\'s Disease-derived lymphoma cell lines HDLM-2 and L-540, which are phenotypically T-cell-like. CD30-L did not produce a detectable effect on proliferation or viability of the B-cell-like, CD30⁺ Hodgkin\'s Disease-derived lymphoma cell lines KM-H2 and L-428. The CD30-L of the present invention provides a means for investigating the roles that CD30-L and the cognate receptor may play in the etiology of Hodgkin\'s Disease.

CD30-L reduced proliferation of CD30⁺ large cell anaplastic lymphoma cell lines (one type of non-Hodgkin\'s lymphoma) (see examples 8 and 13). Thus, CD30-L has potential use as a therapeutic agent. CD30-L also finds use in delivering diagnostic or therapeutic agents attached thereto to cells (e.g., malignant cells) that express the CD30 antigen.

The CD30 ligand also induces proliferation of T cells in the presence of an anti-CD3 co-stimulus. The CD30-L of the present invention thus is also useful as a research tool for elucidating the roles that CD30 and CD30-L may play in the immune system. The inducible expression of CD30-L on normal T cells and macrophages, and the presence of its receptor on activated T and B cells, is consistent with both autocrine and paracrine effects.

Upregulation of CD30 accompanying EBV, HTLVI and HTLVII transformation also warrants further investigation, and the CD30-L provided herein is useful in such studies. HTLVI is the proximal cause of adult T cell Leukemia/Lymphoma. EBV has long been associated with Burkitt\'s lymphoma and nasopharyngeal carcinoma, and, overall, 50% of Hodgkin\'s lymphomas are EBV⁺ (reviewed in Klein, Blood 80:299 (1992).

The CD30-L polypeptides of the present invention also may be employed in in vitro assays for detection of CD30 or CD30-L or the interactions thereof. Additional cell types expressing CD30 may be identified, for example.

The term “CD30-L” as used herein refers to a genus of polypeptides which are capable of binding CD30. Human CD30-L is within the scope of the present invention, as are CD30-L proteins derived from other mammalian species. As used herein, the term “CD30-L” includes membrane-bound proteins (comprising a cytoplasmic domain, a transmembrane region, and an extracellular domain) as well as truncated proteins that retain the CD30-binding property. Such truncated proteins include, for example, soluble CD30-L comprising only the extracellular (receptor binding) domain.