Expression of Genetically Engineered Immunoconjugates of Lymphotoxin and a Chimeric Anti-Ganglioside GD2 Antibody

Reilly

et al. 1992

156

130

A genetically engineered fusion protein consisting of a chimeric anti-ganglioside GD2 antibody (chl4.18) and interleukin 2 (IL2) was tested for its ability to enhance the killing of autologous GD2-expressing melanoma target cells by a tumor-infiltrating lymphocyte line (660 TIL). The fusion of IL2 to the carboxyl terminus of the immunoglobulin heavy chain did not reduce IL2 activity as measured in a standard proliferation assay using either mouse or human T-cell lines. Antigen-binding activity was greater than that of the native chimeric antibody. While IL2 treatment in vivo leads to increases in both natural killer and ADCC activities, the cytolytic activity of antigen-specific, major histocompatibility complex (MHC)-restricted T cells may actually be reduced (5). Treatment of T cells with anti-CD3 antibody prior to IL2 exposure greatly increases T-cell cytolytic activity (6). Likewise, expansion of tumor-irfiltrating lymphocytes (TIL) by culture in the presence of high concentrations of IL2 with periodic target-cell stimulation leads to substantial increases in cytolytic activity (7). Both approaches involve costimulation of IL2 and T-cell antigen receptors for expansion and maintenance of T-cell cytolytic activity. Thus, an optimal therapy might combine IL2 activation and tumor antigen presentation together with a tumor-specific antibody that mediates both complementdependent cytotoxicity (CDC) and ADCC activities. By combining a chimeric anti-ganglioside GD2 antibody (chl4.18) which has potent CDC and ADCC activities (8), with IL2, we hope to target this cytokine to tumors such as neuroblastoma (9, 10) and melanoma (11) expressing GD2. In this way, relatively large amounts of tumor antigens should be present during IL2 activation for expansion of cytotoxic T cells, since melanoma cell lines have been reported to express an average of 1.5 x 1 sites per cell for ch14.18 (8). Furthermore, the antibody would also be available to target Fc receptor-bearing cells that have been activated by the targeted IL2.The chl4.18 antibody used in this report has already been shown to mediate potent ADCC activity by IL2-activated peripheral blood mononuclear cells from cancer patients (12). We have focused on the ability of a chl4.18-IL2 fusion protein to stimulate the proliferation and cytolytic activity of a human T-cell line against autologous melanoma targets.This cell line, 660 TIL, is CD3', CD8', antigen-specific, and MHC class I-restricted and was originally obtained by outgrowth from a human metastatic melanoma (13). A melanoma line, 660 mel, was derived from the same tumor and serves as a source for antigen stimulation and as an autologous target for 660 TIL (14). Results of this study show that tumor cells coated with a fusion protein in which IL2 is at the carboxyl terminus of the heavy-chain constant region 3 (CH3) exon of ch14.18 (CH3-1L2) efficiently stimulate resting 660 TIL cells to kill autologous targets. These coated cells serve as a model for tumors that have been targeted in vivo. MATERIALS AND M...

supporting

confidence: 89%

supporting

confidence: 61%

mentioning

confidence: 96%

See 1 more Smart Citation

Antibody-targeted interleukin 2 stimulates T-cell killing of autologous tumor cells.

Reilly

et al. 1992

156

130

“…Mouse-human chimeric antibodies directed against the EGF receptor (ch225) or GD2 (chl4.18) were constructed by joining the cDNA for the variable region of the murine antibodies with the constant regions of the yl heavy chain and the K light chain as described (19 proteins ch225-IL2 and chl4.18-IL2 were constructed by fusion of a synthetic sequence coding for human IL-2 to the carboxyl end of the human Cyl gene as described (12,14,20 tAll experimental groups were started with six mice for the hepatic and eight mice for the lung metastases models; animals found dead prior to the planned date of sacrifice were not included in the evaluation. §Differences in the metastatic score/number of metastatic foci and organ weights between the fusion protein groups and all control groups were statistically significant (P < 0.002).…”

mentioning

confidence: 99%

Eradication of human hepatic and pulmonary melanoma metastases in SCID mice by antibody-interleukin 2 fusion proteins.

Becker

Pancook

et al. 1996

(8-10).An alternative means of cytokine delivery is to target them to tumor sites with mAbs directed against tumor associated antigens (11, 12). Thereby, effective local cytokine concentrations can be achieved at the tumor site without resorting to patient-specific therapy. A number of groups have reported the construction of such fusion proteins combining the antigen-binding capacity of antibodies or their fragments with the cytokine activity of IL-2 using different strategies for plasmid construction and protein expression (11)(12)(13) Mouse-human chimeric antibodies directed against the EGF receptor (ch225) or GD2 (chl4.18) were constructed by joining the cDNA for the variable region of the murine antibodies with the constant regions of the yl heavy chain and the K light chain as described (19). The antibody-IL-2 fusion

“…The application of recombinant DNA technology has recently led to the construction of antibody-cytokine fusion proteins designed to achieve optimal biological effectiveness by combining the unique targeting ability of antibodies with the multifunctional activities of cytokines (14,19,20). Antibody-cytokine fusion proteins have been proposed for the treatment of solid tumors, including melanoma (14) and Table 1.…”

Section: Discussionmentioning

confidence: 99%

A recombinant antibody-interleukin 2 fusion protein suppresses growth of hepatic human neuroblastoma metastases in severe combined immunodeficiency mice.

Sabzevari

Mueller

et al. 1994

A genetically engineered fusion protein consisting of a human/mouse chimeric anti-ganglioside GD2 antibody (chl4.18) and recombinant human interleukin 2 (rhIL-2) was tested for its ability to target rhIL-2 to tumor sites and stimulate immune effector cells sufficiently to achieve effective tumor cell lysis in vivo. The chl4.18-IL-2 fusion protein proved more effective than equivalent doses of rhIL-2 in suppressing dissemination and growth of human neuroblastoma in an experimental hepatic metastases model of scid (severe combined immunodeficiency) mice reconstituted with human lymphokine-activated killer cells. The chl4.18-IL-2 fusion protein was also more proficient than equivalent doses of rhIL-2 in prolonging the life-span of these animals. This recombinant antibody-cytokine fusion protein may prove useful for future treatment ofGD2-expressing human tumors in an adjuvant setting.