Surgical treatment of hypothalamic hamartomas.

Hypothalamic hamartomas are aberrant masses, composed of abnormally distributed neurons and glia. Along endocrine and cognitive symptoms, they may cause epileptic seizures, including the specific gelastic and dacrystic seizures. Surgery is the treatment of drug-resistant hamartoma epilepsy, with associated positive results on endocrine, psychiatric, and cognitive symptoms. Recently, alternatives to open microsurgical treatment have been proposed. We review these techniques and compare their efficacy and safety. Open resection or disconnection of the hamartoma, either through pterional, transcallosal, or transventricular approach, leads to good epileptological control, but its high complication rate, up to 30%, limits its indications. The purely cisternal peduncular forms remain the only indication of open, pterional approach, while other strategies have been developed to overcome the neurological, endocrine, behavioral, or cognitive complications. Laser and radiofrequency thermocoagulation-based disconnection through robot-guided stereo-endoscopy has been proposed as an alternative to open microsurgical resection and stereotactic destruction. The goal is to allow safe and complete disconnection of a possibly complex attachment zone, through a single intraparenchymal trajectory which allows multiple laser or radiofrequency probe trajectory inside the ventricle. The efficacy was high, with 78% of favorable outcome, and the overall complication rate was 8%. It was especially effective in patients with isolated gelastic seizures and pure intraventricular hamartomas. Stereotactic radiosurgery has proved as efficacious and safer than open microsurgery, with around 60% of seizure control and a very low complication rate. Multiple stereotactic thermocoagulation showed very interesting results with 71% of seizure freedom and 2% of permanent complications. Stereotactic laser interstitial thermotherapy (LiTT) seems as effective as open microsurgery (from 76 to 81% of seizure freedom) but causes up to 20% of permanent complications. This technique has however been highly improved by targeting only the epileptogenic onset zone in the hamartoma, as shown on preoperative functional MRI, leading to an improvement of epilepsy control by 45% (92% of seizure freedom) with no postoperative morbidity. All these results suggest that the impact of the surgical procedure does not depend on purely technical matters (laser vs radiofrequency thermocoagulation or stereotactic vs robot-guided stereo-endoscopy) but relies on the understanding of the epileptic network, including inside the hamartoma, the aim being to plan an effective disconnection or lesion of the epileptogenic part while sparing the adjacent functional structures.

Low levels of the immunoregulator Semaphorin 4D (CD100) in sera of HIV patients.

INTRODUCTION: Semaphorin-4D (CD100), generated by CD4/CD8 T-cells and its receptor on B cells - CD72, play a role in immune regulation. Both have soluble forms - sCD100/sCD72. METHODS: sCD100 and sCD72 levels were determined by ELISA (MyBioSource, USA). RESULTS: 28 chronic HIV patients and 50 matched healthy volunteers participated in our study. Before treatment, CD4 T-cells counts were 267 ±â€¯216 cells/mcl and viral load (VL) was 586,675 ±â€¯1897,431 copies/ml. Two years following HAART, CD4 T-cells counts rose to 475 ±â€¯264 cells/mcl and VL dropped to 2050 ±â€¯10,539 copies/ml. CD8 T-cells counts were stable. sCD72 levels prior (4.13 ±â€¯2.03 ng/ml) and following HAART (3.53 ±â€¯2.01 ng/ml) were similar to control levels (4.51 ±â€¯2.66 ng/ml). sCD100 levels before (40.47 ±â€¯31.4 ng/ml) and following HAART (37.68 ±â€¯29.44 ng/ml) were significantly lower compared to controls (99.67 ±â€¯36.72 ng/ml) despite the significant increase in CD4 T-cells counts. CONCLUSIONS: The permanent low levels of the immunoregulator sCD100 suggest a role for CD100 in the immune dysfunction and T cells exhaustion of HIV.

Tolerance evaluation of overdosed dietary levels of 25-hydroxyvitamin D3 in growing piglets.

Forty-eight, cross-bred (GL × LW × P) piglets were used in a 42-day tolerance trial to assess the effects of feeding diets supplemented with vitamin D or increasing levels of 25-hydroxyvitamin D3 (25-OH-D3 ). Six-week-old piglets (24 castrate males, 24 females) were used. Two replicate groups of 6 piglets were randomized by weight and allocated to four dietary treatments. The control group (T1) was supplemented with 50 µg vitamin D3 /kg feed. The experimental groups received 25-OH-D3 at the recommended dose (T2: 50 µg/kg = 1x), at 250 µg/kg (T3: 5x) or at 500 µg/kg (T4: 10x) respectively. Feed intake and daily weight gain were measured weekly, and the animals were examined by a veterinarian daily. After 42 days, body mass, blood, urine, bone and tissue samples were analysed and a pathology examination conducted. Dietary treatments had no significant effect on final body mass or daily weight gain. The 25-OH-D3 plasma concentration in T1 was 17 ± 3 ng/ml (mean ± SD) while the respective values of the experimental groups were significantly increased in T2, T3 and T4. Tissue concentrations of 25-OH-D3 were higher in liver and muscle for T3 and T4 and in skin for T4 than in T1. However, neither gross pathology nor histology, nor blood and urine characteristics, nor bone parameters were affected by dietary treatments. Weight of organs as well as dry matter, ash and calcium content of kidneys remained unaffected by dietary 25-OH-D3 intake. Furthermore, no changes were observed for general indicators of health. The results of this study demonstrated that feeding piglets with 25-OH-D3 at 5 or 10 times the recommended level had no adverse effects on any of the biological parameters measured. It was concluded that 25-OH-D3 can be regarded as a supplement with a very high safety margin when used at the recommended level.

Myeloid expression of the AP-1 transcription factor JUNB modulates outcomes of type 1 and type 2 parasitic infections.

Activation of macrophages is a key step in the initiation of immune responses, but the transcriptional mechanisms governing macrophage activation during infection are not fully understood. It was recently shown that the AP-1 family transcription factor JUNB positively regulates macrophage activation in response to Toll-like receptor agonists that promote classical or M1 polarization, as well as to the cytokine interleukin-4 (IL-4), which elicits an alternatively activated or M2 phenotype. However, a role for JUNB in macrophage activation has never been demonstrated in vivo. Here, to dissect the role of JUNB in macrophage activation in a physiological setting, mice lacking JUNB specifically in myeloid cells were tested in two infection models: experimental cerebral malaria, which elicits a pathological type 1 immune response, and helminth infection, in which type 2 responses are protective. Myeloid-restricted deletion of Junb reduced type 1 immune activation, which was associated with reduced cerebral pathology and improved survival during infection with Plasmodium berghei. Myeloid JUNB deficiency also compromised type 2 activation during infection with the hookworm Nippostrongylus brasiliensis, leading to diminished cytokine production and eosinophil recruitment and increased parasite burden. These results demonstrate that JUNB in myeloid cells shapes host responses and outcomes during type 1 and type 2 infections.

Histologic subtypes of breast cancer following radiotherapy for Hodgkin lymphoma.

BACKGROUND: The purpose of the study was to determine whether breast cancers (BCs) that develop in women previously irradiated for Hodgkin lymphoma (HL) are biologically similar to sporadic BC. MATERIALS AND METHODS: We retrospectively reviewed the charts of patients who developed BC after radiotherapy (RT) for HL. Tumors were classified as ductal carcinoma in situ (DCIS) or invasive carcinoma. Invasive carcinomas were further characterized according to the subtype: hormone receptor (HR)+/human epidermal growth factor receptor 2 (HER2)-, HR+/HER2+, HR-/HER2+, and HR-/HER2-. BCs after HL were compared with four age-matched sporadic, non-breast cancer (BRCA) I or II mutated BCs. RESULTS: One hundred forty-seven HL patients who were treated with RT between 1966 and 1999 and subsequently developed BCs were identified. Of these, 65 patients with 71 BCs had complete pathologic information. The median age at HL diagnosis was 23 (range, 10-48). The median age at BC diagnosis was 44 (range, 28-66). The median time to developing BC was 20 years. Twenty cancers (28%) were DCIS and 51 (72%) were invasive. Of the 51 invasive cancers, 24 (47%) were HR+/HER2-, 2 (4%) were HR+/HER2+, 5 (10%) were HR-/HER2+, and 20 (39%) were HR-/HER2-. There were no differences in BC histologic subtype according to the age at which patients were exposed to RT, the use of chemotherapy for HL treatment, or the time from RT exposure to the development of BC. In a 4 : 1 age-matched comparison to sporadic BCs, BCs after HL were more likely to be HR-/HER2- (39% versus 14%) and less likely to be HR+/HER2- (47% versus 61%) or HR+/HER2+ (4% versus 14%) (P = 0.0003). CONCLUSION(S): BCs arising in previously irradiated breast tissue were more likely to be triple negative compared with age-matched sporadic invasive cancers and less likely to be HR positive. Further studies will be important to determine the molecular pathways of carcinogenesis in breast tissue that is exposed to RT.

Inhibition of TGF-ß signaling in genetically engineered tumor antigen-reactive T cells significantly enhances tumor treatment efficacy.

Transforming growth factor ß (TGF-ß) is a cytokine with complex biological functions that may involve tumor promotion or tumor suppression. It has been reported that multiple types of tumors secrete TGF-ß, which can inhibit tumor-specific cellular immunity and may represent a major obstacle to the success of tumor immunotherapy. In this study, we sought to enhance tumor immunotherapy using genetically modified antigen-specific T cells by interfering with TGF-ß signaling. We constructed three γ-retroviral vectors, one that expressed TGF-ß-dominant-negative receptor II (DNRII) or two that secreted soluble TGF-ß receptors: soluble TGF-ß receptor II (sRII) and the sRII fused with mouse IgG Fc domain (sRIIFc). We demonstrated that T cells genetically modified with these viral vectors were resistant to exogenous TGF-ß-induced smad-2 phosphorylation in vitro. The functionality of antigen-specific T cells engineered to resist TGF-ß signaling was further evaluated in vivo using the B16 melanoma tumor model. Antigen-specific CD8+ T cells (pmel-1) or CD4+ T cells (tyrosinase-related protein-1) expressing DNRII dramatically improved tumor treatment efficacy. There was no enhancement in the B16 tumor treatment using cells secreting soluble receptors. Our data support the potential application of the blockade of TGF-ß signaling in tumor-specific T cells for cancer immunotherapy.

CXCR3/CCR5 pathways in metastatic melanoma patients treated with adoptive therapy and interleukin-2.

BACKGROUND: Adoptive therapy with tumour-infiltrating lymphocytes (TILs) induces durable complete responses (CR) in ∼20% of patients with metastatic melanoma. The recruitment of T cells through CXCR3/CCR5 chemokine ligands is critical for immune-mediated rejection. We postulated that polymorphisms and/or expression of CXCR3/CCR5 in TILs and the expression of their ligands in tumour influence the migration of TILs to tumours and tumour regression. METHODS: Tumour-infiltrating lymphocytes from 142 metastatic melanoma patients enrolled in adoptive therapy trials were genotyped for CXCR3 rs2280964 and CCR5-Δ32 deletion, which encodes a protein not expressed on the cell surface. Expression of CXCR3/CCR5 in TILs and CXCR3/CCR5 and ligand genes in 113 available parental tumours was also assessed. Tumour-infiltrating lymphocyte data were validated by flow cytometry (N=50). RESULTS: The full gene expression/polymorphism model, which includes CXCR3 and CCR5 expression data, CCR5-Δ32 polymorphism data and their interaction, was significantly associated with both CR and overall response (OR; P=0.0009, and P=0.007, respectively). More in detail, the predicted underexpression of both CXCR3 and CCR5 according to gene expression and polymorphism data (protein prediction model, PPM) was associated with response to therapy (odds ratio=6.16 and 2.32, for CR and OR, respectively). Flow cytometric analysis confirmed the PPM. Coordinate upregulation of CXCL9, CXCL10, CXCL11, and CCL5 in pretreatment tumour biopsies was associated with OR. CONCLUSION: Coordinate overexpression of CXCL9, CXCL10, CXCL11, and CCL5 in pretreatment tumours was associated with responsiveness to treatment. Conversely, CCR5-Δ32 polymorphism and CXCR3/CCR5 underexpression influence downregulation of the corresponding receptors in TILs and were associated with likelihood and degree of response.

Efficacy of abbreviated Stanford V chemotherapy and involved-field radiotherapy in early-stage Hodgkin lymphoma: mature results of the G4 trial.

INTRODUCTION: To assess the efficacy of an abbreviated Stanford V regimen in patients with early-stage Hodgkin lymphoma (HL). PATIENTS AND METHODS PATIENTS: with untreated nonbulky stage I-IIA supradiaphragmatic HL were eligible for the G4 study. Stanford V chemotherapy was administered for 8 weeks followed by radiation therapy (RT) 30 Gy to involved fields (IF). Freedom from progression (FFP), disease-specific survival (DSS) and overall survival (OS) were estimated. RESULTS: All 87 enrolled patients completed the abbreviated regimen. At a median follow-up of 10 years, FFP, DSS and OS are 94%, 99% and 94%, respectively. Therapy was well tolerated with no treatment-related deaths. CONCLUSIONS: Mature results of the abbreviated Stanford V regimen in nonbulky early-stage HL are excellent and comparable to the results from other contemporary therapies.

Lanthanum salts improve bone formation in a small animal model of post-menopausal osteoporosis.

Two different lanthanum salts, lanthanum carbonate (LaCO(3)) and Lancer(®), a lanthanide citrate mixture, were tested for their effects on bone metabolism in a small animal model for post-menopausal osteoporosis. Forty female outbred Wistar Han rats, sham-operated (SHAM, positive control, n = 10) or ovariectomized (OVX, n = 30) at 4 months of age, were allotted into following groups (n = 10/group): (i) SHAM, (ii) OVX control (negative control), (iii) OVX + LaCO(3) (1.74 g/kg feed) and (iv) OVX + Lancer(®) (8 g/kg feed). Effects on bone were investigated by bone markers [osteocalcin (Oc) in serum and excretion of pyridinoline (PYD) in urine] and by physical parameters of bone structure and bone composition (bone mass, calcium, phosphorus and magnesium content in bone crude ash). Bone micro-architecture and bone mineral density were evaluated by peripheral quantitative computed tomography and micro-computed tomography (µCT). The animal model could be validated by differences between OVX control and SHAM. Body mass and feed intake were the same among the four groups. Oc was clearly increased in the two experimental groups (p < 0.001) vs. SHAM and OVX control. Bone mass and calcium content in bone ash were significantly higher than in OVX control. The Ca/P ratio in bone ash of the two lanthanide groups did not differ from SHAM. Bone-protecting effects of lanthanides were clearly demonstrated by an increased trabecular density which is the region of interest for osteoporotic bone loss. A 3D imaging of bone micro-architecture by µCT visualized descriptively the positive effects of lanthanides on bone formation. The results of this study demonstrate an improvement of bone formation and bone-protecting effects of lanthanides in the OVX rat. Thus, lanthanum salts suggest a prevention of post-menopausal bone loss and may be of benefit in experimental osteopenia following ovariectomy.

A T cell-independent antitumor response in mice with bone marrow cells retrovirally transduced with an antibody/Fc-gamma chain chimeric receptor gene recognizing a human ovarian cancer antigen.

In order to treat common cancers with immunotherapy, chimeric receptors have been developed that combine the tumor specificity of antibodies with T-cell effector functions. Previously, we demonstrated that T cells transduced with a chimeric receptor gene against human ovarian cancer were able to recognize ovarian cancer cells in vitro and in vivo. We now report that recipients of bone marrow cells transduced with these genes exhibited significant antitumor activity in vivo. Moreover, in vivo depletion of T cells in reconstituted mice did not affect antitumor activity, suggesting that other immune cells expressing the chimeric receptor gene may play an important role in tumor rejection.

Immunologic and therapeutic evaluation of a synthetic peptide vaccine for the treatment of patients with metastatic melanoma.

The cloning of the genes encoding cancer antigens has opened new possibilities for the treatment of patients with cancer. In this study, immunodominant peptides from the gp100 melanoma-associated antigen were identified, and a synthetic peptide, designed to increase binding to HLA-A2 molecules, was used as a cancer vaccine to treat patients with metastatic melanoma. On the basis of immunologic assays, 91% of patients could be successfully immunized with this synthetic peptide, and 13 of 31 patients (42%) receiving the peptide vaccine plus IL-2 had objective cancer responses, and four additional patients had mixed or minor responses. Synthetic peptide vaccines based on the genes encoding cancer antigens hold promise for the development of novel cancer immunotherapies.

Delta radiomics analysis of Magnetic Resonance guided radiotherapy imaging data can enable treatment response prediction in pancreatic cancer.

BACKGROUND: Magnetic Resonance Image guided Stereotactic body radiotherapy (MRgRT) is an emerging technology that is increasingly used in treatment of visceral cancers, such as pancreatic adenocarcinoma (PDAC). Given the variable response rates and short progression times of PDAC, there is an unmet clinical need for a method to assess early RT response that may allow better prescription personalization. We hypothesize that quantitative image feature analysis (radiomics) of the longitudinal MR scans acquired before and during MRgRT may be used to extract information related to early treatment response. METHODS: Histogram and texture radiomic features (n = 73) were extracted from the Gross Tumor Volume (GTV) in 0.35T MRgRT scans of 26 locally advanced and borderline resectable PDAC patients treated with 50 Gy RT in 5 fractions. Feature ratios between first (F1) and last (F5) fraction scan were correlated with progression free survival (PFS). Feature stability was assessed through region of interest (ROI) perturbation. RESULTS: Linear normalization of image intensity to median kidney value showed improved reproducibility of feature quantification. Histogram skewness change during treatment showed significant association with PFS (p = 0.005, HR = 2.75), offering a potential predictive biomarker of RT response. Stability analyses revealed a wide distribution of feature sensitivities to ROI delineation and was able to identify features that were robust to variability in contouring. CONCLUSIONS: This study presents a proof-of-concept for the use of quantitative image analysis in MRgRT for treatment response prediction and providing an analysis pipeline that can be utilized in future MRgRT radiomic studies.

Successful immunotherapy of natural killer-resistant established pulmonary melanoma metastases by the intravenous adoptive transfer of syngeneic lymphocytes activated in vitro by interleukin 2.

In previous in vitro studies, we have shown that murine splenocytes or cancer patient lymphocytes incubated in IL-2 become lytic for fresh syngeneic or autologous tumors. We have now performed the adoptive transfer of such lymphokine-activated killer (LAK) cells in a murine B16 metastasis model to test their in vivo efficacy. 1 X 10(8) LAK cells, infused intravenously into C57BL/6 mice with established B16 pulmonary metastases, led to a marked decreased in the number of lung nodules and improved survival. LAK cells administered 3 d after amputation of a tumor-bearing limb also decreased the incidence of spontaneous pulmonary metastases. LAK cells generated from tumor-bearer splenocytes had effects equivalent to those from normal animals, and this antimetastatic effect of the LAK cells did not require the prior administration of cyclophosphamide or other immunosuppressants. Fresh or unstimulated splenocytes had no effect. The antitumor effectors and precursors in vivo and in vitro were Thy-1+. The lymphokine required for the activation appeared to be interleukin 2 (IL-2), since incubation in partially purified supernatants from PMA pulsed EL-4 or Con A-pulsed splenocytes or purified Jurkat IL-2 led to the generation of LAK cells equally active in vivo. The use of IL-2-activated cells may provide a valuable method for the adoptive therapy of human neoplasms as well.

Identification of a novel major histocompatibility complex class II-restricted tumor antigen resulting from a chromosomal rearrangement recognized by CD4(+) T cells.

CD4(+) T cells play an important role in antitumor immune responses and autoimmune and infectious diseases. Although many major histocompatibility complex (MHC) class I-restricted tumor antigens have been identified in the last few years, little is known about MHC class II- restricted human tumor antigens recognized by CD4(+) T cells. Here, we describe the identification of a novel melanoma antigen recognized by an human histocompatibility leukocyte antigen (HLA)-DR1-restricted CD4(+) tumor-infiltrating lymphocyte (TIL)1363 using a genetic cloning approach. DNA sequencing analysis indicated that this was a fusion gene generated by a low density lipid receptor (LDLR) gene in the 5' end fused to a GDP-L-fucose:beta-D-galactoside 2-alpha-L-fucosyltransferase (FUT) in an antisense orientation in the 3' end. The fusion gene encoded the first five ligand binding repeats of LDLR in the NH2 terminus followed by a new polypeptide translated in frame with LDLR from the FUT gene in an antisense direction. Southern blot analysis showed that chromosomal DNA rearrangements occurred in the 1363mel cell line. Northern blot analysis detected two fusion RNA transcripts present only in the autologous 1363mel, but not in other cell lines or normal tissues tested. Two minimal peptides were identified from the COOH terminus of the fusion protein. This represents the first demonstration that a fusion protein resulting from a chromosomal rearrangement in tumor cells serves as an immune target recognized by CD4(+) T cells.

Immunization with antigen and interleukin 2 in vivo overcomes Ir gene low responsiveness.

We studied the effect of purified interleukin 2 (IL-2), made by recombinant DNA techniques, on the serum antibody response to myoglobin in high- and low-responder mice. Previous studies (6, 7) have shown that this response is controlled by H-2-linked Ir genes. The IL-2 was emulsified with the antigen in complete Freund's adjuvant to provide a sustained high local concentration. In low-responder B10.BR mice, a single dose (optimum 50,000 U) resulted in a consistent 10-50-fold increase in specific serum antibody throughout the time course of the response, from 10 d to 46 d after immunization. In contrast, no effect of IL-2 was seen in congenic high-responder B10.D2 mice. With IL-2, the low-responder mice achieved specific antibody levels comparable to those of high responders. Vehicle alone had no effect, and IL-2 alone, without antigen, did not induce myoglobin-specific antibody. No effect of IL-2 was seen in athymic nude mice of high-responder H-2 haplotype. The effect of IL-2 may be on a small number of responding T cells in the low responder mice, but it is possible that IL-2 also acts directly on B cells in a response that remains T-dependent, and therefore is not observed in athymic mice. We suggest that IL-2 may enhance suboptimal T cell help in the low responder, whereas help is not limiting in the high responder. This approach may enable the study of antibody responses in low responders otherwise too weak to analyze, and may be useful in producing antibodies to poorly immunogenic antigens. Potential clinical uses include immunization with weak antigens in normal patients, or with any antigen in certain immunodeficient patients.

Regression of a disseminated syngeneic solid tumor by systemic transfer of lymphoid cells expanded in interleukin 2.

We have studied the ability of immunized lymphoid cells expanded in IL-2 to mediate the cure of mice with localized and disseminated syngeneic lymphoma. Mice received 500 rad total-body irradiation before injection of tumor into the footpad. Mice were treated 5 d later when a palpable local tumor and disseminated metastases were present. Intravenous injection of in vivo immune lymphocytes cured 93% of all mice, significantly better than any control group (P less than 0.0005). Immune cells, secondarily sensitized to the FBL-3 tumor in vitro, also conferred significant survival benefit (P less than 0.005) when injected intravenously, curing 79% of the animals treated. When these in vitro sensitized cells were expanded in IL-2, 8-10-fold over 7 d, 93% of the animals thus treated were cured, (P less than 0.005). When these cells were grown for multiple generations in IL-2 they retained their ability to cure mice (56% cured, P less than 0.01). This is the first demonstration that intravenous injection of sensitized cells grown in long term culture in IL-2 is capable of curing mice of established local and disseminated syngeneic tumor.

Interleukin 4 promotes the growth of tumor-infiltrating lymphocytes cytotoxic for human autologous melanoma.

Addition of IL-4 (1,000 U/ml) to either high or low concentrations of IL-2 augmented tumor-infiltrating lymphocytes (TIL) growth from human melanoma. Weekly restimulation with irradiated tumor cells in conjunction with IL-4 allowed enhanced growth of TIL. With low-dose IL-2 (10 U/ml) and IL-4, expanded TIL had little cytolytic activity against Daudi or allogeneic tumors. Further, IL-4 augmented the total lytic activity against autologous tumors in most cases. With high-dose IL-2 (1,000 U/ml), IL-4 addition decreased nonspecific killing activity against Daudi or allogeneic melanomas in many cases, and reciprocally augmented cytolytic activity against the autologous melanoma in many cases. This suggests the possible use of IL-4 in cancer therapy, especially in adoptive cellular immunotherapy using TIL or in conjunction with IL-2 administration.

Interleukin 7 generates antitumor cytotoxic T lymphocytes against murine sarcomas with efficacy in cellular adoptive immunotherapy.

Interleukin 7 (IL-7) is a 25-kD cytokine that was initially described as a pre-B cell growth factor. This cytokine has also been shown to have T cell proliferative and differentiation effects. In this report, we demonstrate that antitumor cytotoxic T lymphocytes (CTL) generated by secondary in vitro sensitization of draining lymph node cells in IL-7 are effective in treating 3-day syngeneic methylcholanthrene (MCA) sarcoma pulmonary metastases in mice. In vivo titrations comparing IL-7 to IL-2 antitumor CTL show that they have equivalent potency in adoptive immunotherapy. IL-7 antitumor CTL generated against MCA sarcomas of weak immunogeneity are also tumor specific in their in vivo efficacy. This study represents the first successful use of a cytokine other than IL-2 for the generation of cells with in vivo efficacy in cellular adoptive transfer.

Lymphokine-activated killer cell phenomenon. Lysis of natural killer-resistant fresh solid tumor cells by interleukin 2-activated autologous human peripheral blood lymphocytes.

Activation in lectin-free interleukin 2 (IL-2) containing supernatants of peripheral blood mononuclear leukocytes (PBL) from cancer patients or normal individuals resulted in expression of cytotoxicity toward 20 of 21 natural killer (NK)-resistant fresh solid tumor cells tested. Fresh solid tumor cells were resistant to NK-mediated lysis in 10 autologous patients' PBL-tumor interactions, and from 17 normal individuals tested against 13 allogeneic fresh tumors. Culture of PBL in IL-2 for 2-3 d was required for the lymphokine activated killers (LAK) to be expressed, and lytic activity toward a variety of NK-resistant fresh and cultured tumor targets developed in parallel. Autologous IL-2 was functional in LAK activation, as well as interferon-depleted IL-2 preparations. Irradiation of responder PBL before culture in IL-2 prevented LAK development. Precursors of LAK were present in PBL depleted of adherent cells and in NK-void thoracic duct lymphocytes, suggesting that the precursor is neither a monocyte nor an NK cell. LAK effectors expressed the serologically defined T cell markers of OKT.3, Leu-1, and 4F2, but did not express the monocyte/NK marker OKM-1. Lysis of autologous fresh solid tumors by LAK from cancer patients' PBL was demonstrated in 85% of the patient-fresh tumor combinations. Our data present evidence that the LAK system is a phenomenon distinct from either NK or CTL systems that probably accounts for a large number of reported nonclassical cytotoxicities. The biological role of LAK cells is not yet known, although it is suggested that these cells may be functional in immune surveillance against human solid tumors.

Interleukin 4 (B cell stimulatory factor 1) can mediate the induction of lymphokine-activated killer cell activity directed against fresh tumor cells.

Interleukin 4 (IL-4) expresses multiple biologic activities, including B cell, mast cell, and T cell stimulation. We showed that the incubation of resting splenocytes from C57BL/6 mice solely in purified native or recombinant mouse IL-4 results in the generation of lymphokine-activated killer (LAK) activity directed against fresh, syngeneic sarcoma cells. The precursor activated by IL-4 expresses surface asialo-GM1. In addition, IL-4 is capable of amplifying the splenic LAK activity induced by recombinant IL-2. The generation, by IL-4, of killer cells with broad antitumor reactivity raises the possibility of using IL-4 alone or in combination with IL-2 in the immunotherapy of cancer in animal models.