Activity of 8F4, a T-cell receptor-like anti-PR1/HLA-A2 antibody, against primary human AML in vivo.

The PR1 peptide, derived from the leukemia-associated antigens proteinase 3 and neutrophil elastase, is overexpressed on HLA-A2 in acute myeloid leukemia (AML). We developed a high-affinity T-cell receptor-like murine monoclonal antibody, 8F4, that binds to the PR1/HLA-A2 complex, mediates lysis of AML and inhibits leukemia colony formation. Here, we explored whether 8F4 was active in vivo against chemotherapy-resistant AML, including secondary AML. In a screening model, coincubation of AML with 8F4 ex vivo prevented engraftment of all tested AML subtypes in immunodeficient NSG (NOD scid IL-2 receptor γ-chain knockout) mice. In a treatment model of established human AML, administration of 8F4 significantly reduced or eliminated AML xenografts and extended survival compared with isotype antibody-treated mice. Moreover, in secondary transfer experiments, mice inoculated with bone marrow from 8F4-treated mice showed no evidence of AML engraftment, supporting the possible activity of 8F4 against the subset of AML with self-renewing potential. Our data provide evidence that 8F4 antibody is highly active in AML, including chemotherapy-resistant disease, supporting its potential use as a therapeutic agent in patients with AML.

Complement component C3 mediates Th1/Th17 polarization in human T-cell activation and cutaneous GVHD.

The complement system has been shown to regulate T-cell activation and alloimmune responses in GVHD. Mice deficient in the central component of complement system C3 have significantly lower GVHD-related mortality/morbidity, and C3 modulates Th1/Th17 polarization in mouse GVHD. To investigate whether anticomplement therapy has any impact on human T-cell activation, a drug candidate Compstatin was used to inhibit C3 activation in this study. We found the frequency of IFN-γ (Th1)-, IL-4 (Th2)-, IL-17 (Th17)-, IL-2- and TNF-α-producing cells were significantly reduced among activated CD4(+) cells in the presence of Compstatin. Compstatin treatment decreased the proliferation of both CD4(+) and CD8(+) T cells upon TCR stimulation. However, Compstatin does not affect the production of IL-2 and TNF-α in activated CD8(+) T cells, and the differentiation of CD8(+) T cells into distinct memory and effector subsets remained intact. Furthermore, we examined complement deposition in skin and lip biopsy samples of patients diagnosed with cutaneous GVHD. C3 deposition was detected in the squamous epithelium and dermis, blood vessels and damaged sweat glands, and was associated with gland damage and regeneration. We conclude that C3 mediates Th1/Th17 polarization in human T-cell activation and skin GVHD in patients.

Phenotype and antitumor activity of ascitic fluid monocytes in patients with ovarian carcinoma.

Monocytes/macrophages (MO/MA) represent a major leukocyte population in the peritoneal cavity of patients with epithelial ovarian cancer (EOC). We examined the phenotypic characteristics and antitumor cell activity of ascitic MO in patients with EOC. MO/MA phenotype was compared with MO in peripheral blood by two- and three-color flow cytometry. Cytotoxic/cytostatic effects of different cytokines on cultured EOC cells were measured by initial labeling or uptake inhibition of [methyl-3H] thymidine. Malignant ascites had higher proportion of MO/MA with the CD14brightCD16+ phenotype than peripheral blood. Cell surface antigen expression of activation and differentiation in peripheral blood and ascites, including CD38, CD40, CD64, and CD86, was higher on CD14brightCD16- and CD14brightCD16+ than on CD14dimCD16- cells. HLA-DR expression was higher on ascitic MO/MA than peripheral blood MO. Significant cytotoxic/cytostatic activity was elicited by treating ascitic MO/MA with interferon-gamma (IFN-gamma) and interleukin-2 (IL-2), but not with interleukin-12, paclitaxel, granulocyte-monocyte colony-stimulating factor (GM-CSF), or tumor necrosis factor-alpha (TNF-alpha). Soluble CD40Lt did not enhance MO/MA cytotoxic activity, and inhibited IFN-gamma or IL-2 induced cytoxicity. We conclude that MO/MA from ascites have elevated proportions of CD14brightCD16+ cells, showing phenotypic features of activation. IFN-gamma induces the cytotoxic and cytostatic activity of MO/MA that is inhibited by CD40Lt.

Clinical and biological effects of intraperitoneal injections of recombinant interferon-gamma and recombinant interleukin 2 with or without tumor-infiltrating lymphocytes in patients with ovarian or peritoneal carcinoma.

To identify strategies that enhance tumor-specific immunity in patients with ovarian carcinoma, 22 patients received four to six doses of i.p. recombinant IFN-gamma (rIFN-gamma), 200 microg/m2 on days 1, 3, 5, 8, 10, and 12, and i.p. recombinant interleukin 2 (rIL-2), either 6.0 x 10(5) IU/m2 (group A) or 1.0 x 10(5) IU/m2 (group B), on days 9, 10, and 11. Two patients in group A also received T-cell lines expanded from peritoneal tumor-infiltrating lymphocytes (TILs) obtained after i.p. rIFN-gamma/rIL-2 administration. Toxicity was manageable and included five nonhematological grade 3 or 4 events in 22 patients (23%). A patient had normalization of CA-125 values and a progression-free interval of 18 months, after receiving i.p. rIFN-gamma/rIL-2 without TILs. Another patient who received i.p. rIFN-gamma/rIL-2 plus TILs had stabilization of ascites and intra-abdominal tumors and >50% reduction in serum CA-125 values over 6 months. A third patient who received i.p. rIFN-gamma/rIL-2 had stabilization of intra-abdominal tumors and ascites accompanied by CA-125 values of 50 to 100 units over 6 months. T-cell lines for adoptive immunotherapy were developed for only 3 of 20 patients who were treated with rIFN-gamma/rIL-2. Large numbers of CD3- CD56+ adherent cells were expanded in rIL-2 in the remaining patients, precluding the development of T-cell lines. i.p. rIFN-gamma, either alone or followed by rIL-2, increased proportions of human leukocyte antigen (HLA) class I+ and class II+ tumor cells and increased HLA class I staining intensity on peritoneal carcinoma cells. i.p. rIFN-gamma plus rIL-2 also enhanced cytotoxic activity against Daudi and K562 cells and against allogeneic ovarian tumor cells. Increased cytotoxic activity was associated with an increase in the proportion of CD56+ cells. IFN-gamma and IL-2 transcripts were expressed more frequently after rIFN-gamma and rIL-2 treatment. In addition, the proportions of CD45RA+ (naive lymphocytes) were increased, and CD8+ DR+ lymphocytes were increased relative to CD8+ CD69+ cells, which were decreased. IL-10 concentrations in peritoneal fluids were increased after treatment with rIFN-gamma and the higher rIL-2 dosing (group A) but not in those treated with rIFN-gamma and the lower rIL-2 dosing (group B). These results demonstrated that patients with ovarian carcinoma can tolerate treatment with rIFN-gamma and rIL-2 and that rIFN-gamma alone or rIFN-gamma combined with rIL-2 enhances the expression of HLA class I and class II antigens on ovarian tumor cells, although immunosuppressive cytokines, such as transforming growth factor-beta and IL-10, may persist. Treatment with rIFN-gamma/rIL-2 i.p. did not facilitate the production of TIL-derived T-cell lines ex vivo.

Quantitative analysis of transforming growth factor beta 1 and 2 in ovarian carcinoma.

Transforming growth factor beta (TGF-beta) is an important family of cytokines that may promote tumor growth in vivo through several mechanisms including interference with antitumor T-cell immune responses, alteration of factors in the stroma and matrix, and the promotion of angiogenesis. TGF-beta isotypes have been detected in malignant and normal ovarian tissues. We have determined by quantitative immunohistochemistry the density of TGF-beta1, TGF-beta2, and human leukocyte antigen (HLA) Class I and Class II antigens on malignant cells in paired primary and metastatic specimens from 10 patients with ovarian carcinoma. Cryostat sections of specimens from the carcinomas and from normal ovaries of three women of similar age without ovarian cancer were stained respectively with specific antibodies to TGF-beta1, TGF-beta2, and HLA Class I and II antigens, and with isotype-matched control antibodies. Antigen density was quantitated blindly as mean absorbance on a SAMBA 4000 image analyzer. TGF-beta1 and TGF-beta2 were overexpressed in both primary and metastatic tumor specimens in comparison with normal ovarian tissue. No statistical correlation was found between the expression of TGF-beta1 or TGF-beta2 and HLA class I or HLA class II, which suggests that TGF-beta isotypes could have effects on the immune system other than down-modulation of these HLA molecules. Furthermore, the lack of association between levels of TGF-beta expression and the reduced expression of HLA molecules could suggest that tumor cells expressing both HLA and TGF-beta may be suitable targets for adaptive immunotherapy. Additional studies are necessary to determine whether TGF-beta expressed by ovarian cancer cells merits evaluation as a therapeutic target.

HLA class I expression on human ovarian carcinoma cells correlates with T-cell infiltration in vivo and T-cell expansion in vitro in low concentrations of recombinant interleukin-2.

This study was carried out to determine whether HLA class I or class II expression on ovarian tumor cells and lymphocytic infiltration of the epithelial ovarian carcinoma (EOC) tissues were responsible for the ability to expand tumor-infiltrating lymphocytes (TIL) in vitro in low concentrations of recombinant interleukin-2 (rIL-2). Immunohistochemical analysis was performed using monoclonal antibodies that recognize framework determinants of either HLA class I or HLA class II or leukocyte differentiation antigens (LCA, CD3, CD4, and CD8). Cryostat sections of EOC had HLA class I and HLA class II expression on at least 5% of tumor cells in 18 of 20 specimens (90%). From another portion of the same tumor specimens T-cell lines were developed from TIL in low concentrations of rIL-2 (200-600 IU/ml) in 7 of 17 patients. Tumors from which TIL were expanded in vitro with rIL-2 had significantly higher proportions of HLA class I-positive tumor cells (73 +/- 10%) compared to tumors from which TIL failed to grow (40 +/- 10%) (P = 0.036). However, there was no difference in the proportions of HLA class II-positive tumor cells between the two groups. Tumor specimens of patients whose TIL were expanded in rIL-2 had significantly higher numbers per field (423 +/- 114 vs 154 +/- 20; P = 0.005) and proportions (90 +/- 3% vs 77 +/- 4%; P = 0.023) of infiltrating CD3+ cells, significantly higher numbers per field (115 +/- 44 vs 19 +/- 5; P = 0.003) and proportions (25 +/- 5% vs 11 +/- 2%; P = 0.017) of CD8+ cells and significantly higher numbers per field of CD4+ cells (318 +/- 101 vs 113 +/- 18; P = 0.025), in comparison to tumor specimens from patients whose TIL did not grow in vitro. Significant correlations were observed between the proportions of HLA class I-positive EOC tumor cells and the numbers of infiltrating LCA-positive cells (r = 0.67; P = 0.005) CD3+ cells (r = 0.70; P = 0.002), CD4+ cells (r = 0.69; P = 0.003), and CD8+ cells (r = 0.82; P = 0.001). The proportions of HLA class II-positive tumor cells correlated positively (r = 0.45; P = 0.049) only with the numbers of CD8+-infiltrating cells. In conclusion, we report here that HLA class I expression on EOC cells correlates with T-cell infiltration in vivo and T-cell expansion in vitro, in low concentrations of rIL-2.

Preclinical analysis of intraperitoneal administration of 111In-labeled human tumor reactive monoclonal IgM AC6C3-2B12.

An IgM lambda human tumor cell-reactive monoclonal antibody was developed that reacts with cells of ovarian cancer, colorectal cancer, breast cancer, and certain other malignancies. The monoclonal antibody AC6C3-2B12, which was obtained from a recent recloning, was purified from tissue culture supernatants and analyzed by high-performance liquid chromatography and sodium dodecyl sulfate-PAGE. An animal model was developed in which human tumors grew either as solid peritoneal metastases or as s.c. nodules utilizing the human colorectal carcinoma cell line SW620. The biodistribution of 111In-labeled IgM conjugate was studied after i.v. or i.p. administration in nude mice bearing an s.c. xenograft or peritoneal tumor lumps of a human colorectal carcinoma (SW620). IgM administered i.v. cleared rapidly from blood and was deposited mainly in the liver [50% injected dose/g (ID)/g)], pancreas (20% ID/g), and kidney (10% ID/g) at 24 h. Tumor deposition was low (< or = 1.0% ID/g) in the s.c. tumor xenograft. In contrast, high tumor targeting (29% ID/g) was found in peritoneal tumor lumps after i.p. administration of 111In-labeled IgM. The biological half-life of IgM in the tumor was 100 h. Long peritoneal residence time (t 1/2 = 67 h) and low liver uptake (7% ID/g) were observed after i.p. administration. Blood activity was < 1% of the injected activity. Tumor:normal organ ratios were high (range, 2-290) from 2 to 144 h after i.p. administration. Whole body autoradiograms at 24 h after i.p. 111In-labeled IgM administration confirmed the biodistribution results. In normal beagle dogs, 75% of the i.p.-administered 111In-IgM decayed in the peritoneal cavity. The majority of the remaining radioactivity was taken up by mediastinal lymph nodes. Biological half-life in both locations was approximately 137 h. The i.p. administration of intact, specific radiolabeled IgM provides prolonged retention of radioactivity in tumor, low normal tissue uptake, a long peritoneal residence time, and very limited spillover of IgM into the circulation. This approach offers a promising new method for the diagnosis and treatment of certain patients with peritoneal carcinomatosis.

Active intralymphatic immunotherapy of uterine cervical carcinoma with viral oncolysate: a pilot study.

A pilot clinical trial was conducted in patients with squamous carcinoma of the uterine cervix to evaluate the clinical and biologic effects of active intralymphatic immunotherapy (AILI) with allogenic viral oncolysate (VO) prior to radiation therapy. Sixteen patients with advanced primary squamous carcinoma of the uterine cervix and lymph node metastases underwent bipedal intralymphatic injections of VO. VO was derived from lysates of cervical carcinoma cells that had been infected with influenza A virus. AILI was repeated after 2 weeks and followed one week later by standard or extended-field radiation therapy (RT). The first seven patients were treated at one of the three dose levels: 6 mg (three patients), 12 mg (three patients) and 18 mg (one patient). Remaining patients were treated at the 12 mg dose level. Sixteen patients received 63 injections (one patient received three of four doses) of AILI-VO without significant toxicity. Eleven patients have died of persistent or recurrent carcinoma with a total median survival of 19.4 months. Examination of humoral and cellular immunity during AILI-VO showed an increase in the serum liters of antibodies to a surface antigen on cervical carcinoma cells and to the influenza virus. Increased non-MHC restricted lymphocyte cytotoxicity was exhibited by three of four patients treated above the first dose level. Two of the three patients are survivors. By contrast, lymphocytes of patients treated with AILI-VO exhibited either an increase or a decrease in proliferation responses to cervical carcinoma cells. Similarly, post-treatment lymphocytes exhibited either helper or suppressor inducer effects on pre-treatment lymphocytes.

Development of a cell surface reacting human monoclonal antibody recognizing ovarian and certain other malignancies.

A human monoclonal antibody designated AC6C3 was developed by fusing regional lymph node lymphocytes from a patient with epithelial ovarian carcinoma with cells of the hybrid myeloma SPAZ 4. This monoclonal antibody recognized a determinant expressed on the cell surface of ovarian tumor cell lines. The AC6C3 hybridoma has been maintained for more than 24 months by repeated cloning and secretes IgM at concentrations of 2-8 micrograms/10(6) cells/24h. The AC6C3 monoclonal antibody reacted with a cell surface component of ovarian tumor cell lines, as determined by cell surface immunofluorescence staining using the fluorescent activated cell sorter (FACS). In contrast, nylon wool nonadherent peripheral blood lymphocytes or red blood cells from normal donors were negative (less than 5% of the cells were stained). Immunoperoxidase staining with the AC6C3 monoclonal antibody of nonpermeabilized cryostat sections of freshly obtained or cryopreserved ovarian carcinoma specimens and human ovarian tumor xenografts demonstrated strong reactivity of these specimens. Most normal tissues including brain, liver, heart, kidney and peritoneum demonstrated negative or weak reactions with AC6C3. Other carcinomas including breast, colon and some malignancies of neuroectodermal origin were strongly reactive with AC6C3. AC6C3 mediated complement-dependent cytotoxicity and identified a 32 Kd band in Western blotting and immunoprecipitation experiments conducted on surface labelled SKOV3 cells. The association constant for AC6C3 was determined at 2.3 x 10(10) M-1.

Immunological effects of tumor vaccines: III. Influenza virus oncolysates inhibit the TPA induced activation of peripheral blood mononuclear cells.

This paper investigates the effects of tumor vaccines on T cell proliferation induced by 12-0 tetradecanoylphorbol-13-acetate (TPA). Viral oncolysate (VO) tumor vaccines containing inactivated influenza virus A significantly inhibited TPA-induced T cell proliferation. In contrast, a control tumor vaccine (CO) that contained the same cellular components as VO but lacked influenza virus did not affect the TPA-induced proliferation. These effects were also observed with peripheral blood mononuclear cells (PBMC) from ovarian cancer patients, although VO and CO each induced significant and similar levels of proliferation in these cells in the absence of TPA. Protein kinase C (PKC) is a pivotal enzyme in signal transduction pathways that control cell proliferation, and TPA is a specific activator of PKC. VO and CO showed differential effects on the inhibition of purified protein kinase C (PKC). These studies demonstrate the antagonistic effects of different tumor vaccines on T lymphocyte proliferation and suggest that influenza virus A or virus-modified cellular components may interfere with signal transduction in the immune cells of the recipient of the tumor vaccine.

T-cell functions in ovarian cancer patients treated with viral oncolysates: I. Increased helper activity to immunoglobulins production.

We investigated the humoral and cellular responses of ovarian cancer patients treated with viral oncolysates (VO) tumor vaccines. All patients treated with VO developed tumor cell surface-reacting antibodies and anti-hemagglutinin antibodies. Furthermore, PBMC from these patients developed cellular proliferative responses to the cellular oncolysates (CO). The in vitro proliferating population consisted mainly of CD4+ cells, as demonstrated by depletion experiments using the corresponding monoclonal antibodies and complement and by examination of the phenotype of the cells stimulated in culture with VO or cellular oncolysates. Furthermore, in the patients treated with VO we observed an increased helper activity to immunoglobulin production by PBMC collected post-VO treatment in the PWM-driven differentiation system. The helper activity was much higher in patients treated with IL-2 plus VO than IL-2 alone.

Viral oncolysates in cancer treatment: immunological mechanisms of action (review).

Viral oncolysates (VO) are homogenates of virus-infected tumor cells. VO have been demonstrated in experimental animals to induce protection against transplanted autologous tumors, when administered prior to the challenge with the tumor. VO were first introduced into clinical trials as a treatment adjunct to chemotherapy and nonspecific immunomodulators (BCG). In recent years, beneficial clinical and biological activity responses have been observed in melanoma and gynecologic cancer (cervix, ovary), after administration of VO alone. Our group has continued clinical trials with PR8 strain influenza A. We have demonstrated that PR8 VO augments delayed type hypersensitivity in coded skin testing and have emphasized regional active immunization in treatment protocols. The efficacy of active immunization strategies have yet to be defined, but recent findings in ovarian and uterine cervix cancer highlight the importance of route and careful integration with other therapeutic modalities. The VO are postulated to trigger immunological mechanisms in the host that may ultimately lead to the control of the metastatic spread and elimination of the tumor. Humoral immune responses induced by VO have been described, while cellular immune responses associated with VO administration have been investigated to a lesser extent. We present here what is known and we discuss hypothesized mechanisms of humoral and T cell mediated immunity induced by VO now under investigation. The elucidation of these mechanisms may provide conceptual advances in the field of human tumor immunity as well as a rationale for the development of tumor vaccines.