Clonal analysis and in situ characterization of lymphocytes infiltrating human breast carcinomas

Chemokines orchestrate tumor cells and the microenvironment to achieve metastatic heterogeneity

Chemokines, a subfamily of the cell cytokines, are low molecular weight proteins known to induce chemotaxis in leukocytes in response to inflammatory and pathogenic signals. A plethora of literature demonstrates that chemokines and their receptors regulate tumor progression and metastasis. With these diverse functionalities, chemokines act as a fundamental link between the tumor cells and their microenvironment. Recent studies demonstrate that the biology of chemokines and their receptor in metastasis is complex as numerous chemokines are involved in regulating site-specific tumor growth and metastasis. Successful treatment of disseminated cancer is a significant challenge. The most crucial problem for treating metastatic cancer is developing therapy regimes capable of overcoming heterogeneity problems within primary tumors and among metastases and within metastases (intralesional). This heterogeneity of malignant tumor cells can be related to metastatic potential, response to chemotherapy or specific immunotherapy, and many other factors. In this review, we have emphasized the role of chemokines in the process of metastasis and metastatic heterogeneity. Individual chemokines may not express the full potential to address metastatic heterogeneity, but chemokine networks need exploration. Understanding the interplay between chemokine-chemokine receptor networks between the tumor cells and their microenvironment is a novel approach to overcome the problem of metastatic heterogeneity. Recent advances in the understanding of chemokine networks pave the way for developing a potential targeted therapeutic strategy to treat metastatic cancer.

Tumor-infiltrating regulatory T cells, CD8/Treg ratio, and cancer stem cells are correlated with lymph node metastasis in patients with early breast cancer

BACKGROUND

Tumor-infiltrating lymphocytes are an important component of the tumor microenvironment (TME) in breast cancer. They have been linked with tumor pathogenesis in advanced stages. However, little is known about their contribution in early phases. In this study, we analyzed the infiltration of leukocytes and cancer stem cells (CSC) in tumors from patients with early breast cancer.

METHODS

Samples of blood and tumor tissue from 30 patients with breast cancer were collected, and the number of dendritic cells (DC), T cells, and CSC were analyzed by flow cytometry.

RESULTS

Tumor-infiltrating CD4 and CD8 T cells expressed higher levels of cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) compared with peripheral T cells. Regulatory T cells (Treg) were enriched in tumors and overexpressed glucocorticoid-induced TNFR-related protein and CTLA-4. Tumor Treg had a positive correlation with the amount of myeloid DC (mDC) and disease progression. The CD8/Treg ratio was associated with lymph node metastasis and tumor stages. The main subset of DC in early breast tumors was mDC, while plasmacytoid DC were almost absent. CSC were present in most tumors with higher frequencies in patients with lymph node metastasis. CSC were also associated with the amount of tumor-infiltrating Treg.

CONCLUSION

Early breast cancer has an inflammatory milieu characterized by mDC, Treg, and CSC infiltration. The frequencies of Treg, CSC and CD8/Treg ratio were associated with disease progression. The composition of leukocytes and the presence of CSC in early breast tumors should be considered for the development of new therapeutic approaches.

A treatise on endothelial biology and exosomes: homage to Theresa Maria Listowska Whiteside

Exosomes are the current primary research focus of Dr. Theresa L. Whiteside. They are key mediators of intercellular communication in the head and neck, as well as other sites. Their effects in the tumor microenvironment are manifold and include suppression of immunity, promotion of angiogenesis, enabling of metastasis, as well as reprogramming of fibroblasts and mesenchymal stromal cells. The aim of this communication is to summarize Dr. Whiteside's contribution to the field of exosome research and details the interactions of exosomes with endothelial cells leading to recent findings on how to target endothelial cells using exosomes as a therapeutic approach.

Immunophenotypes and Cytotoxic Functions of Lymphocytes in Patients with Hepatocellular Carcinoma

Aims and background

Hepatocellular carcinoma (HCC) is one of the most common cancers in Asia. Immunological mechanisms are thought to play an important role in the control of tumor progression. The immune responses in HCC patients are poorly understood. In the present study, the proliferation and cytotoxic functions of lymphocytes from tumor tissues and peripheral blood of HCC patients were analysed. Simultaneously, the microcultures were phenotyped in order to determine the involvement of different lymphocyte subsets in mediating the cytotoxic function.

Methods

The frequencies of proliferating and cytotoxic lymphocytes from three tumor tissues and peripheral blood from ten HCC patients and nine healthy individuals were assessed by limiting dilution microculture analysis. These microcultures were phenotyped by single and dual color flow cytometry using monoclonal antibodies specific for CD4, CD8, CD56 and HLA-DR markers.

Results

The precursor frequencies of both proliferating and cytotoxic lymphocytes were found to be comparable in the peripheral blood of HCC patients and healthy individuals. Compared to peripheral blood, a marked reduction in the precursor frequencies of proliferating and cytotoxic lymphocytes was observed in the tumor tissues of HCC patients. In the tumor tissues, a significantly higher frequency of cytotoxic T cells compared to natural killer cells was observed. Dual color flow cytometric analysis revealed increased percentages of CD8+ HLA-DR+ lymphocytes compared to CD4+ HLA-DR+ cells in the tumor tissues.

Conclusions

Our results suggest that depressed immune responses at the tumor site might be responsible for the escape of tumor cells from the immune surveillance of the host.

Immune profiling in human breast cancer using high-sensitivity detection and analysis techniques

Objectives

Evaluation of immune profiles in human breast cancer using high-sensitivity detection and analysis methods.

Design

Cohort comparative analysis studies of breast tissue.

Setting

Human hospital and laboratory healthcare facilities.

Participants

Women over 18 years.

Main outcome measures

Evaluation of the comparative immunophenotype of human breast carcinoma and normal breast tissues.

Results

Leukocyte density and specific subgroups of lymphocytes and macrophages were generally higher in breast cancers compared to normal breast tissues. CD3, CD4, CD45RO, CD45RA(2H4), CD45 and HLA Class II (on TIL) were significantly expressed on breast tumour tissues compared with normal tissues (p < .01). Some 30% of T-cells were γδ-TCR positive, but the majority were αβ-TCR in type. CD19 (B-cell), CD14 (FMC32 and 33) and HLA Class I levels (epithelial and TIL) showed no significant differences. IL-2α receptor expression was low or absent on most TIL.

Conclusions

High-sensitivity and image analysis techniques permitted accurate characterisation of the TIL infiltrate for immune profiling. Breast carcinoma showed predominance of CD4 T-cells of mainly memory phenotype. Normal breast tissues showed low leukocyte infiltration. Further correlation of these findings with clinical outcome, including survival, is proceeding with encouraging results.

Immunophenotypic features of tumor infiltrating lymphocytes from mammary carcinomas in female dogs associated with prognostic factors and survival rates

Background

The immune system plays an important role in the multifactorial biologic system during the development of neoplasias. However, the involvement of the inflammatory response in the promotion/control of malignant cells is still controversial, and the cell subsets and the mechanisms involved are poorly investigated. The goal of this study was to characterize the clinical-pathological status and the immunophenotyping profile of tumor infiltrating lymphocytes and their association with the animal survival rates in canine mammary carcinomas.

Methods

Fifty-one animals with mammary carcinomas, classified as carcinomas in mixed tumors-MC-BMT = 31 and carcinomas-MC = 20 were submitted to systematic clinical-pathological analysis (tumor size; presence of lymph node and pulmonary metastasis; clinical stage; histological grade; inflammatory distribution and intensity as well as the lymphocytic infiltrate intensity) and survival rates. Twenty-four animals (MC-BMT = 16 and MC = 8) were elected to the immunophenotypic study performed by flow cytometry.

Results

Data analysis demonstrated that clinical stage II-IV and histological grade was I more frequent in MC-BMT as compared to MC. Univariate analysis demonstrated that the intensity of inflammation (moderate/intense) and the proportion of CD4⁺ (≥ 66.7%) or CD8⁺ T-cells (<33.3%) were not associated with worse survival rate. Multivariate analysis demonstrated that only lymphocytic infiltrate intensity ≥ 600 (P = 0.02) remained as independent prognostic factor. Despite the clinical manifestation, the lymphocytes represented the predominant cell type in the tumor infiltrate. The percentage of T-cells was higher in animals with MC-BMT without metastasis, while the percentage of B-lymphocytes was greater in animals with metastasized MC-BMT (P < 0.05). The relative percentage of CD4⁺ T-cells was significantly greater in metastasized tumors (both MC-BMT and MC), (P < 0.05) while the proportion of CD8⁺ T-cells was higher in MC-BMT without metastasis. Consequently, the CD4⁺/CD8⁺ ratio was significantly increased in both groups with metastasis. Regardless of the tumor type, the animals with high proportions of CD4⁺ and low CD8⁺ T-cells had decreased survival rates.

Conclusion

The intensity of lymphocytic infiltrate and probably the relative abundance of the CD4⁺ and CD8⁺ T-lymphocytes may represent important survival prognostic biomarkers for canine mammary carcinomas.

The immunophenotype and activation status of the lymphocytic infiltrate in human breast cancers, the role of the major histocompatibility complex in cell-mediated immune mechanisms, and their association with prognostic indicators

BACKGROUND

The aims of this study were to characterize, phenotypically, the immune infiltrate in human breast cancers, to assess the activation status of tumor-infiltrating lymphocytes (TIL), and to define the association of these findings with established prognostic indicators.

METHODS

Immunohistochemistry was performed on frozen sections of 60 primary breast cancers by use of monoclonal antibodies to T lymphocytes (CD3), T-helper cells (CD4), cytotoxic T-cells (CD8), natural killer cells (CD56), interleukin-2 receptors (IL-2R), and major histocompatibility (MHC) class I antigen (HLA-ABC) and MHC class II antigen (HLA-DR).

RESULTS

All tumors stained positive for CD3, CD4 and CD8, but with marked variation in the intensity of the infiltrate. In tumors with a moderate infiltrate of TIL, there was a trend toward a greater representation of T-helper cells. However, as the intensity of TIL increased, there was a decline in the proportion of T-helper cells and a concomitant rise in the relative proportion of cytotoxic T cells. There was a relative paucity of natural killer cells. A significant association was found between the intensity of TIL and the number of positive nodes (P=.02) and the intensity of the infiltrate of both T-helper cells and cytotoxic T cells with ER expression (P=.03 and.05, respectively). Most tumors stained positive for IL-2R. The expression of IL-2R was associated with the intensity of TIL (P<.0001), T-helper cells (P<.002), cytotoxic T cells (P=.01) and natural killer cells (P=0.04), and also with the degree of lymph node positivity (P=.02) and histologic tumor grade (P=.05). MHC class II expression was variable, and a large proportion of the tumors showed limited expression in individual cancer cells. There was an association between the expression of HLA-DR in tumor cells and the activation status of TIL (P=.03).

CONCLUSION

An immune infiltrate is an invariable finding in breast cancers, and the intensity of the infiltrate is greater in node positive tumors. Additionally, TIL may well be activated, albeit partially, in most tumors, suggesting that cell-mediated immune mechanisms are functionally intact.

CD1a-positive infiltrating-dendritic cell density and 5-year survival from human breast cancer

Infiltrating CD1a(+) dendritic cells (DCs) have been associated with increased survival in a number of human cancers. This study investigated DC infiltration within breast cancers and the association with survival. Classical established prognostic factors, of tumour size, lymph node status, histological grade, lympho-vascular invasion, the KI-67 (MIB-1) fraction and the Nottingham Prognostic Index (NPI) were also compared. A total of 48 breast cancer patients were followed from the time of surgery and CD1a density analysis for 5 years or until death. Our data set validated previous studies, which show a relationship between survival and the NPI (P<0.001), tumour size (P<0.01) and lymph node status (P<0.05). Although more patients were alive at the 5-year time point in the group with higher CD1a DC density than the lower CD1a DC group, this failed to reach statistical significance at the P=0.05 level. Analysis at 10 years postsurgery is required to investigate the association further.

RCAS1 is associated with ductal breast cancer progression

RCAS1/EBAG9 (receptor-binding cancer antigen expressed on SiSo cells/ estrogen receptor-binding fragment-associated gene 9), an estrogen-transcribed protein, has been shown to be expressed in a wide variety of cancers, including uterine, ovarian, and lung cancer cells. Soluble and membranous RCAS1 proteins may play a role in the immune escape of tumor cells by promoting T lymphocyte inhibition of growth and apoptosis. In the present report, the presence of RCAS1 was revealed in human ductal breast cancer biopsies by immunohistochemistry. Its cytoplasmic expression was exhibited in cancer cells obtained from tumor biopsies and in breast cancer cell lines. RCAS1 significantly correlated with tumor grade. In addition, RCAS1 was identified in MCF7 culture supernatants. Those observations suggest that RCAS1 is a new marker for breast cancer progression and a possible mechanism for breast cancer immune escape.

Therapeutic activity of NK cells against tumors

While it is generally accepted that natural killer (NK) cells, by killing tumor cells in the circulation, represent a first line of defense against metastases, their therapeutic activity against established tumors has been limited. In this review, we describe studies to improve the therapeutic effectiveness of activated NK cells in both animal models and clinical trials to better understand the biological problems that limit their effectiveness.

Profiling the immune response in patients with breast cancer by phage-displayed cDNA libraries

Display on the surface of filamentous phages has been shown to be well suited for the enrichment of serum antibody-binding ligands. Here, we have taken the advantage of this technology to analyze the humoral immune response in patients with cancer. The cDNA repertoires from breast cancer cell lines T47D and MCF-7 were fused to the 3'-end of the filamentous phage M13 gene VI in all three reading frames. When the libraries were biopanned on rabbit polyclonal IgG against the human Bcl-x(L) protein, positive clones were selected, thus confirming the utility of the libraries. Using serum antibodies from patients with breast cancer, we specifically selected IgG-binding phage-encoded cDNA products. Sequence analysis of the selected clones identified important antigens including p53, centromere-F, int-2, pentraxin I, integrin beta5, cathepsin L2 and S3 ribosomal protein. The selected phage-displayed cDNA products were recognized by a significant number of breast cancer sera as compared to sera from normal individuals. Although the human pentraxin I mRNA was reported to be exclusively localized in the nervous system, we found it also expressed by breast cancer cell lines. Four out of 30 patients with breast cancer (13 %) showed reactivity with the recombinant pentraxin expressed in Escherichia coli, while no reactivity was found in normal sera. The obtained results demonstrate that phage display could be a valuable method for the identification of antigens recognized by the humoral immune system in patients with cancer.

Intracellular Fas ligand in normal and malignant breast epithelium does not induce apoptosis in Fas-sensitive cells

Fas ligand (FasL) is expressed on some cancers and may play a role in the immune evasion of the tumour. We used immuno-histochemistry to study the expression of Fas and FasL in tissue samples from breast cancer patients, as well as normal breast tissue. Our results show that Fas and FasL are co-expressed both in normal tissue and in breast tumours. Fas and FasL mRNA were expressed in fresh normal and malignant breast tissue, as well as cultured breast epithelium and breast cancer cell lines. Flow cytometry analysis of live cells failed to detect FasL on the surface of normal or malignant breast cells; however, both stained positive for FasL after permeabilization. Fas was detected on the surface of normal breast cells and T47D and MCF-10A cell lines but only intracellularly in other breast cell lines tested. Neither normal breast epithelium nor breast cell lines induced Fas-dependent apoptosis in Jurkat cells. Finally, 20 tumour samples were stained for apoptosis. Few apoptotic cells were detected and there was no increase in apoptotic cells on the borders between tumour cells and lymphocytes. We conclude that FasL is expressed intracellularly in both normal and malignant breast epithelium and unlikely to be important for the immune evasion of breast tumours.

The immunology and immunotherapy of breast cancer: an update

Adenocarcinomas of the breast behave clinically and epidemiologically in ways that show host resistance factors are important for outcome in addition to grade and stage of malignancy. Immune reactivity to autologous tumors is indicated by the general presence of lymphoid infiltration (LI) and regional lymph node changes; however, these changes predict favorable outcome only in non-metastatic disease. LI is characterized by CD4+ and CD8+ tumor infiltrating lymphocytes reflecting latent cell-mediated immunity (CMI). CMI and humoral immune reactivity have been demonstrated to autologous tumor and a variety of tumor-associated antigens (TAA) have been implicated including CEA, HER-2/neu, MAGE-1, p53, T/Tn and MUC-1. Immune incompetence involving CMI is progressive with the stage of breast cancer and is prognostically significant. Immunotherapy of several types has been designed to address this immunodeficiency and the TAAs involved. Animal models have employed drug therapy, cytokine transfection, vaccines with autologous tumor, cytokines like interferon alpha (IFN-alpha) and interleukin-2 (IL-2), TAA tumor vaccines, and immunotoxins with evidence of tumor regression by immunologic means. Immunotherapy of human breast cancer is a rapidly growing experimental area. Positive results have been obtained with natural IFN and interleukins, particularly in combination strategies (but not with high dose recombinant IFN or IL-2), with autologous tumor vaccine (but not yet with transfected autologous tumor); with a mucin carbohydrate vaccine (Theratope) in a combination strategy (but not with mucin core antigen) and with several immunotoxins. Combination strategies involving immunorestoration, contrasuppression, adjuvant, and immunotoxins are suggested for the future.

Clonal and functional analysis for the augmentation of tumour-infiltrating lymphocytes by interleukin 4

In the adoptive immunotherapy for cancer, the amounts of induced effector cells play a major role in improving therapeutic efficacy. We have already demonstrated that interleukin 4 (IL-4) augments proliferation of tumour-infiltrating lymphocytes (TILs) without altering the cytotoxic activity against autologous tumour cells. The present study is designed to investigate how IL-4 augments TILs by using established TIL clones in terms of IL-2/IL-2 receptor system. CD4+, CD8+ and CD4+ CD8+ (double positive) TIL clones were established from cancer patients. At clonal level, IL-4 augmented the proliferation of IL-2-activated TIL clones irrespective of phenotypes. In order to clarify the mechanism of IL-4 at clonal level, the blocking assay by anti-IL-2 receptor alpha and beta chain and binding assay of IL-2 on the cell surface and the measurement of the internalisation of IL-2 in the cell were performed. It was clarified that IL-4 up-regulated the IL-2 receptor and then augmented the action of IL-2 molecule on the cell surface stimulated by IL-4. Furthermore, binding IL-2 internalised rapidly into the cells. Thus, it is suggested that signal transduction is augmented and proliferation of TILs is enhanced by IL-4 via the action of IL-2/IL-2 receptor system.

Limiting dilution analysis of proliferating and cytotoxic lymphocytes in the peripheral blood and tumours of oral cancer patients

Frequencies of proliferating and cytotoxic lymphocytes from the peripheral blood and tumour tissue of oral cancer patients and healthy individuals were monitored using limiting dilution analysis. Significantly lower precursor frequencies of proliferating lymphocytes were observed in the peripheral blood and tumour tissue of oral cancer patients. A high frequency of natural killer (NK) cells but low cytotoxic T lymphocytes (CTL) was observed in the peripheral blood compartment of oral cancer patients as compared to healthy individuals. A marked reduction in both NK and CTL frequencies in the tumour tissue compared to the peripheral blood was observed. In the tumour tissues, increased percentages of activated CD4+ lymphocytes as compared to CD8+ lymphocytes were observed. Our results suggest that impaired proliferative and cytotoxic potential of tumour infiltrating lymphocytes may play an important role in the escape of tumour cells from the immune system.

In situ cytokine production by breast cancer tumor-infiltrating lymphocytes

BACKGROUND

Human breast cancers progressively grow despite the presence of extensive lymphocytic infiltration and specific antitumor immune recognition, thereby calling into question the competency of breast tumor-infiltrating lymphocytes (TIL). The function of breast TILs in vivo and their possible role in the suppression of an antitumor immune response are largely unknown.

METHODS

The cytokines produced in situ by lymphocytes in 89 breast carcinomas and 14 benign breast lesions were assessed using immunohistochemistry.

RESULTS

The majority of tumor and benign breast samples contained T-cell infiltrates, which were disclosed using an anti-CD3 antibody stain. The percentage of tumor samples in which > or =3% of the lymphocytes were producing cytokines was as follows: interleukin (IL)-2 45%, IL-4 36%, tumor necrosis factor-alpha (TNF-alpha) 28%, transforming growth factor-beta 1 (TGF-beta 1) 20%, IL-10 11%, interferon-gamma (IFN-gamma) 4%, and granulocyte-macrophage colony-stimulating factor (GM-CSF) 3%. Production of IL-2, IL-4, and TGF-beta 1 by TILs in breast cancers exceeded that detected in benign breast lesions (p < 0.005). Significantly more tumor samples contained lymphocytes producing IL-2, IL-4, TGF-beta 1, and TNF-alpha than IFN-gamma and GM-CSF (p < 0.002 for each comparison). One or more of the potentially immunoinhibitory cytokines-IL-4, IL-10, or TGF-beta 1-were produced by lymphocytes in 44% of the specimens. No significant associations were seen between lymphocyte production of a particular cytokine and disease-free survival (median follow-up 43 months).

CONCLUSIONS

Immunohistochemical techniques can be used to detect cytokine secretion by TILs in preserved tissue. The relative lack of secretion of IFN-gamma and GM-CSF, rather than a deficiency of IL-2, may explain why the antitumor immune response to breast cancer is impaired.

Are fine-needle breast aspirates representative of the underlying solid tumour? A comparison of receptor levels, ploidy and the influence of cytokeratin gates

Fifty-three solid and 33 fine-needle aspirate (FNA) samples (20 paired) of human breast carcinomas were examined by flow cytometry. Experiments were conducted to assess whether FNA samples were phenotypically representative of the solid tumour. Quantification of oestrogen receptor (ER), epidermal growth factor receptor (EGFR), c-erbB-2 receptor levels and ploidy were examined on the total and cytokeratin-positive cell populations. The absolute number of molecules of cytokeratin per cell expressed on the FNA (n = 33) and solid tumour (n = 53) samples showed no significant difference, but, on a proportional basis, there was a significant difference between the two samples (P = 0.004), with lower expression exhibited by the FNAs. Examination of paired data showed no significant difference in the percentage of cytokeratin-positive cells (P = 0.51) or in the number of cytokeratin molecules expressed (P = 0.25). While the correlation for ER expression between paired tumour and FNA samples in the absence of cytokeratin gating was P = 0.06, r2 = 0.18, clear correlation was shown when a cytokeratin gate was used (P = 0.005, r2 = 0.4). Repeating this experiment for EGFR, it was found that no correlation was seen between FNA and solid tumour (P = 0.2, r2 = 0.14) in ungated populations, but use of the cytokeratin gate improved the correlation (P = 0.05, r2 = 0.3). A similar finding was seen with c-erbB-2 expression (P = 0.2, r2 = 0.1) without cytokeratin gating and when it was employed (P = 0.05, r2 = 0.4). Ploidy data showed concordance in 18/20 cases. Three cases of aneuploidy were missed by FNA, and this was because of an insufficient number of cells for analysis. The presented data suggest that FNAs are representative of solid tumours and may be useful for measuring receptor levels on clinical material when cytokeratin gating is used. However, observation by light microscopy is still necessary to confirm the presence of tumour cells in FNAs subjected to flow cytometry.

Specific tumor memory induced by polyethylene-glycol-modified interleukin-2 requires both helper and cytotoxic T cells

Local polyethylene-glycol (PEG)-modified interleukin-2 (IL-2) immunotherapy of the guinea pig Line 10 (L10) tumor was previously demonstrated to evoke long-lasting systemic immunity after cure of the tumor and metastases. T cells, most likely the helper T cell subpopulation, were demonstrated to be crucial to the antitumor effects. Here we show that systemic immunity is induced within 7 days after the start of PEG-IL-2 therapy, indicating a rapid systemic priming of L10-specific T cells. No in vitro cytotoxic activity was detected in cell suspensions obtained from the primary tumor site, the regional lymph node or the spleen when isolated during (days 21 and 28) intratumoral treatment with 200,000 IU PEG-IL-2. These data confirm our earlier results obtained with 60,000 IU PEG-IL-2. Moreover, no cytolytic activity was observed in the chromium-release assay after in vitro restimulation with irradiated tumor cells. Specific L10 immunity can be transferred using spleen cell suspensions. Depletion of such a suspension of helper T cells resulted in rejection of the primary tumor in two out of four animals, but all the guinea pigs developed lymph node metastases. Removal of the cytotoxic/suppressor phenotype caused rejection of the dermal tumor in four of eight guinea pigs, but the capacity to prevent lymph node metastases was retained in all animals. Thus, depletion of either subtype reduces, but does not abrogate, the capacity to transfer L10 immunity with spleen cells. In conclusion, our data suggest that tumor cell killing through direct T cell cytotoxicity is not the main mode of action in PEG-IL-2-induced L10 tumor regression. PEG-IL-2 therapy induces early systemic immunity, resulting in rejection of a distant tumor, and the transfer of this immunity depends mainly on the presence of helper T cells, although cytotoxic T cells may also play a role.

Prognostic significance of T-cell infiltrates, expression of beta 2-microglobulin and HLA-DR antigens in breast carcinoma

In this study immunohistological staining was used to assess the presence of T-cell infiltrates and the expression of beta 2-microglobulin (beta 2-m) and HLA-DR antigens on tumor cells of 75 ductal invasive carcinomas. The results were compared with the morphometric prognostic index (MPI) that seems to be the most accurate prognostic predictor. The extent of T-cell infiltrates differed widely between tumors, but statistically significant correlation was found only with the lymph node status, namely, tumors with a high degree of infiltration had predominantly negative lymph nodes and vice versa (p < 0.05). Only 19 (25.3%) out of 75 carcinomas were beta 2-m+, 34 cases (45.3%) showed heterogeneous staining pattern and 22 tumors (29.3%) were completely negative. We could not find any significant correlation between beta 2-m expression and MPI or T-cell content. While normal breast epithelium was always HLA-DR negative, tumor cells displayed positivity in 25 cases (33.3%), 5 tumors (6.7%) were completely positive and 20 tumors (26.7%) displayed only focal expression of class II antigens. This expression did not correlate with any single prognostic parameter, nor with MPI. The results suggest that T-cell infiltrates and the expression of histocompatibility antigens can not be accepted as prognostic indicators in breast carcinoma.

Tumor specific cytolysis by tumor infiltrating lymphocytes in breast cancer

BACKGROUND

In vitro studies have demonstrated that exposure of tumor infiltrating lymphocytes (TIL) to human recombinant interleukin-2 (rIL-2) will generate activated T-lymphocytes with major histocompatibility complex (MHC)-restricted and non-MHC-restricted cytotoxicity toward a panel of tumor target cells. In melanoma and ovarian carcinoma, TIL display MHC-restricted and autologous tumor-specific cytotoxicity. Such tumor-reactive cytotoxic T-lymphocytes (CTL) represent important material for understanding cellular immunity in cancer and developing specific immunotherapeutic approaches in melanoma and ovarian cancer. In breast cancer, some TIL have been demonstrated to secrete cytokines upon interaction with autologous tumor cells, indicating that autologous tumor-reactive lymphocytes may also exist among TIL in breast cancer. Therefore, the authors conducted a study to investigate the cytotoxic profile of rIL-2-activated lymphocytes in breast cancer.

METHODS

Lymphocytes were isolated from primary solid tumors (TIL) of breast carcinomas (10 patients) and from peritoneal effusions (effusion-associated mononuclear cells [EAMNC]) from 2 patients with newly diagnosed metastatic breast carcinoma. Tumor infiltrating lymphocytes or EAMNC were cultured with rIL-2 in long term cultures whereby their expansion index, phenotype, and cytotoxic potential were studied.

RESULTS

Both TIL and EAMNC proliferated by greater than 300-fold (370-3650; mean, 1656) after 23-82 days in cultures containing mixtures of TIL or EAMNC, autologous tumor cells, and rIL-2. By fluorescence analysis, freshly isolated TIL and EAMNC were found to consist of 77.5 plus or minus 10.7% CD3+ T-cells, 33.2 plus or minus 8.9% CD4+, and 47.2 plus or minus 16.8% CD8+ cells. Their CD4 to CD8 ratio was 0.70. After expansion of lymphocytes with rIL-2 in the majority of patients (9 of 12), CD3+CD8+ T-lymphocytes were present in greater numbers than CD3+CD4+ T-lymphocytes. Recombinant interleukin-2-activated CD3+CD8+ cells exhibited preferential cytolytic activity against autologous tumor cells. The cytolytic activity of CD3+CD8+ cells was inhibited either by anti-T-cell receptor (TCR)-alpha/-beta and anti-CD3 monoclonal antibodies (MoAb) or after pretreatment of tumor target cells with MoAb against the class I MHC antigens. Recombinant interleukin-2-activated CD3+CD4+ cells demonstrated potent cytolytic activity against both autologous and allogeneic tumor cells. CD3+CD8+ T-cell clones isolated from representative TIL exhibited preferential autologous tumor-specific cytotoxicity whereas the cytolytic activity of CD3+CD4+ T-cell clones was mostly (12 of 14 clones) nonrestricted to the autologous tumor.

CONCLUSIONS

To the authors' knowledge, this is the first report to demonstrate that TIL from primary tumors of breast carcinomas and EAMNC from metastatic disease can be propagated in large numbers in vitro with rIL-2 while retaining autologous tumor specific and MHC-restricted CTL activity. These findings may be of importance to ongoing clinical trials using TIL or EAMNC in the immunotherapy of patients with advanced breast cancer.

Anti-tumor antibody produced by human tumor-infiltrating and peripheral blood B lymphocytes

Cell suspensions from 69 human tumor biopsies and malignant effusions depleted of infiltrating T cells were incubated for 10-14 days with mitomycin-C-treated cells of the transformed T cell line MOT as feeder cells. B lymphocytes proliferated and differentiated as indicated by immunoglobulin (Ig) secretion in the culture supernatants (B cell expansion). Ig was present in culture supernatants of tumor cell suspensions incubated without MOT feeder cells (non-expanded cells), but the addition of MOT feeder cells to these cultures invariably resulted in a significant increase in Ig concentration. While IgG, IgA, and IgM isotypes were all detected in supernatants of both expanded- and non-expanded tumor cell suspensions, the increase in total Ig induced by MOT feeder cells was mainly due to an increase in IgG. Peripheral blood B lymphocytes (PBBL) from 15 cancer patients and 4 healthy individuals were also successfully expanded by the same method. In these it was shown that IgA was the predominant Ig isotype. Using a modified enzyme-linked immunosorbent assay, IgG of 25/36 expansions from tumor cell suspensions showed reactivity with autologous tumor targets, and that from 10/13 expansions reacted with allogeneic tumor targets of the same histological diagnosis. No reactivity was found against tumor targets of different histology. IgG of 4/10 expansions of PBBL from cancer patients showed reactivity with allogeneic tumor targets of the same histology, while no reactivity was demonstrated against tumor targets of different histology. IgG of expanded PBBL from healthy individuals showed no reactivity against tumor targets. This method allows detailed study of the specific humoral antitumor immune response of intratumoral and peripheral blood B lymphocytes in cancer.

Unrestricted T-cell receptor V-region gene repertoire in tumor-infiltrating lymphocytes from human breast carcinomas

BACKGROUND

Several lines of evidence indicate that a more favorable prognosis is correlated with the degree of lymphocyte infiltration within breast carcinomas. The characterization of these T-cell infiltrates appears necessary to explore the possible existence of an in situ immunologic response of the host against neoplastic cells. Previous studies have indeed suggested that the T-cell receptor (TCR) repertoire of tumor-infiltrating T-lymphocytes (TIL) should be restricted if they act specifically against tumor-related antigens.

METHODS

To address this question, the expression of variable (V) region genes of the TCR-alpha and beta chains in intratumoral lymphocytes from five breast carcinoma biopsy specimens and one normal mammary gland specimen was analyzed using the polymerase chain reaction (PCR). The neoplastic samples included one medullary carcinoma and four ductal infiltrating carcinomas selected on the basis of a rich lymphoid stromal component. Primers specific for 18 different V alpha and 21 V beta families were used for PCR.

RESULTS

In every case, TIL showed an unrestricted pattern of TCR V-region gene expression, similar to the repertoire observed in peripheral blood lymphocytes and in the normal breast tissue.

CONCLUSIONS

According to these nonquantitative PCR experiments, the apparent lack of selection of a limited number of T-cell specificities in the affected tissues does not favor the existence of an in vivo lymphoid recruitment based on TCR recognition of neoplastic antigenic determinants. Further studies, however, leading to an accurate quantification of immunologically relevant T-cell clones and including larger series of cases still are necessary before it will be possible to draw a final conclusion.

Interleukin 7 enhances the proliferation and effector function of tumor-infiltrating lymphocytes from renal-cell carcinoma

Previous studies have documented the effects of IL2 on the growth and effector function of tumor-infiltrating lymphocytes (TIL) in cancer patients. Since IL7 is known to induce T- and NK-cell responses in the peripheral blood, we examined the immuno-enhancing effects of IL7 on TIL derived from human renal-cell carcinoma (RCC). Whereas IL2 induced the growth of freshly isolated TIL in vitro, IL7 was ineffective alone and failed to increase the total number of cells proliferating to IL2. However, IL7 did provide a proliferative signal to TIL that were initially expanded in culture with either IL2 or IL2/IL7 for 2 weeks. IL7 also induced the proliferation of CD4+ and CD8+ TIL lines that have specificity for RCC. The proliferative response induced by IL7 was independent of IL2, since anti-IL2 antibodies did not block IL7-induced proliferation of TIL. IL7 did cooperate with anti-CD3 stimulation for the induction of proliferation; however, the magnitude of this interaction was variable and the response usually additive. In addition, IL7 synergized with anti-CD3 to induce the secretion of IFN gamma from short-term-cultured TIL and from a TIL line. Although IL7 did not promote the development of a tumor-specific T-cell response from IL2-expanded TIL, IL7 enhanced lymphokine-activated killer (LAK) activity from some short-term-cultured TIL. These results illustrate that IL7 can potentiate the growth and production of IFN gamma from RCC-reactive TIL and, to a lesser extent, enhance IL2-induced LAK activity of TIL.

Antigen-specific, MHC-unrestricted T cells

The published record suggests that in the majority of cases the antigen is recognized by the T cell receptor (TCR) as a complex of a foreign antigen and amino acid residues contributed by the major histocompatibility complex (MHC) antigens, and the antigen-specific, MHC-restricted effector function is an unambiguous result of this process. Alternatively, the T cell receptor may recognize a particular conformational form of the antigen which is dictated by the allelic differences in the MHC, resulting also in MHC-restricted recognition. When, however, a T cell which phenotypically fulfills all the requirements necessary to perform antigen specific, MHC-restricted function, shows a lack of MHC restriction, there are two possible explanations: 1) In addition to the MHC-restricted, antigen-specific T cell receptor the cell expresses, or has newly acquired the expression of another, MHC-unrestricted (NK-like) receptor, or 2) The specific antigen recognized by the T cell receptor, is able to bind to the receptor and activate the T cell without being presented by the MHC molecule. While the first possibility has been extensively described in the literature as well as other articles in this issue, the second possibility has not been dealt with to the same extent and is the primary focus of this review.

Adoptive immunotherapy of cancer: biological response modifiers and cytotoxic cell therapy

Immunotherapy has been developed for the treatment of metastatic cancers refractory to conventional therapies. Immunotherapy utilizes immune cells and/or biological response modifiers (BRMs) to induce an anti-tumor response mediated by the patient's immune system. BRMs, including lymphokines and cytokines, are used as single agents or in combination for cancer therapy. Some BRMs, particularly interleukin 2 (IL-2), can activate and expand in vitro lymphocytes with anti-tumor reactivity which will be adoptively transferred to the patient. To enhance the therapeutic effect of immunotherapy, gene therapy is currently under investigation and involves the insertion of cytokine genes in immune cells or in tumor cells. The development and future of cancer immunotherapy will be discussed in this review.

Lymphocyte infiltrates as a prognostic variable in female breast cancer

The predictive value of lymphocyte infiltrates (LI) was studied in 489 patients with breast cancer followed-up for over 10 years. LI were positively correlated to axillary lymph-node status, tumour diameter and histological and morphometric variables (P less than 0.001). In a multivariate analysis LI were independently related to axillary lymph-node status. LI predicted recurrence-free survival (RFS) in rapidly proliferating tumours (P = 0.0269). LI predicted RFS (P = 0.08) and breast cancer related survival (BS) (P = 0.0164) in rapidly proliferating, axillary lymph-node negative tumours. In a multivariate analysis LI independently predicted BS (P = 0.08) in rapidly proliferating tumours. LI independently predicted BS in rapidly (P = 0.025) and slowly (P = 0.09) proliferating, axillary lymph-node negative tumours. If the tumours were not categorised according to proliferation rate, LI and outcome were not significantly related. The results clearly confirm the presence of efficient immunological antitumour defence mechanisms in human breast cancer. Consequently tumour-host interactions are subject to further studies particularly in axillary lymph-node negative breast cancer.

Flow cytometric analysis of tumour infiltrating lymphocyte activation and tumour cell MHC class I and II expression in breast cancer patients

The primary tumour cells and tumour infiltrating lymphocytes (TILs) of 31 breast cancer patients have been analysed by dual colour flow cytometry to determine whether the phenotype and/or activation status of the TILs bears any relationship to the expression of MHC antigens on the tumour cells. The phenotype and activation status of 5000 TILs were studied using Mabs to CD4, CD8, HLA DR, CD25 (the low affinity inducible IL-2 receptor) and the transferrin receptor and related to Class I and Class II MHC expression on 5000 primary tumour cells. On the tumour cells, Class I MHC expression ranged from 1-74%, averaging 12.9%. HLA DR expression ranged from 1-69% averaging 14.3%. When the phenotypic proportions of the lymphocytic infiltrate were analysed there was found to be a correlation between tumour expression of Class I MHC and the proportion of both CD4+ (P less than 0.05) and CD8+ (P less than 0.02) T cells within the tumour. No such relationship was found with the MHC Class II antigen. When TIL activation markers were analysed, the percentage of CD8+ TILs positive for HLA DR expression correlated strongly with the expression of Class I (P less than 0.001) and Class II (P less than 0.001) antigens on the tumour cells. The percentage of CD4+ TILs positive for HLA DR expression also correlated significantly, but less strongly with the expression of Class I (P less than 0.01) and Class II (P less than 0.02) antigen expression on the tumour cells. The percentage of CD4+ TILs positive for CD25 expression correlated with both Class I (P less than 0.05) and Class II (P less than 0.03) expression on the tumour cells while the percentage of CD8+ TILs positive for CD25 did not. The percentage of TILs bearing the transferrin receptor showed no measurable correlation with the expression of either class of MHC antigen on the tumour. The data suggest that MHC expression on the tumour cells has a selective effect on the response capacity of different parts of the immune system.

Tumour-infiltrating lymphocytes in cervical carcinoma

Tumour-infiltrating lymphocytes from cervical carcinomas were cultivated in the presence of interleukin-2. The majority of bulk cultures were cytotoxic against K562, Mel 1 and Caski cells. CD8+ cells were the predominant subset in over 50% of cultures, with varying numbers of CD56+ and CD25+ cells. T cell clones were established from six tumour-infiltrating lymphocyte cultures and the majority exhibited non-MHC-restricted cytotoxicity. However, in one case cytotoxicity of several derived clones was limited to the autologous tumour and in another, to the autologous tumour and Caski cells. This study indicates that tumour-infiltrating lymphocytes can be amplified and cloned from cervical carcinoma biopsies in the presence of rIL2. Although the predominant cytolytic function is non-MHC-restricted, low autotumour cytotoxicity can be demonstrated at the clonal level. The nature of the antigen(s) recognised by T cells on autologous cervical carcinoma cells in unknown; the candidacy of human papillomavirus-related products requires investigation.

Effects of interferon-gamma and tumour necrosis factor-alpha on the development of cytotoxic T lymphocytes in autologous mixed lymphocyte tumour cultures with human melanoma

We have studied the influence of tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) on the development of cytotoxic T lymphocytes (CTL) against melanoma in mixed lymphocyte tumour cultures (MLTC). In these MLTC, TNF-alpha at 10(4) U/ml increased the expansion of the CTL up to 10(4)-fold over recombinant IL-2 (rIL-2) alone. IFN-gamma at 10(4) U/ml and combinations of TNF-alpha plus IFN-gamma at 10(2)-10(3) U/ml promoted the proliferation more variably. MLTC generated with rIL-2 showed a predominance of CD8+ cells, while 2 weeks of culture in the presence of IFN-gamma at 10(4) U/ml, or with IFN-gamma and TNF alpha at 1 x 10(2)-10(3) U/ml, favoured the emergence of CD4+ cell populations. The cytotoxic activity of the lymphocytes generated in these MLTC showed a consistent decline of K562 cytotoxic activity following exposure to the combination of IFN-gamma and TNF-alpha. Despite the altered T cell subset distribution with different combinations of cytokines, no consistent alteration in the specific anti-tumour cytotoxicity against melanoma was detected. These results suggest that TNF-alpha and IFN-gamma influence the activation, phenotypic, and functional outcome of MLTC-generated CTL, and may account for the phenotypic variations observed in T cell populations generated in vitro.

Study of the relationship between immunohistologically demonstrated lymphocytes infiltrating human breast carcinomas and patients' survival

Eighty-five breast carcinomas were immunostained for CD3-, CD4-, CD8-, CD16-, CD22-, CD38- and CD57-positive lymphocyte subpopulations. The results were related to follow-up data (median follow-up 46 months) of 74 patients regarding overall survival and 73 patients in respect to disease-free survival. Whereas the number of axillary lymph node metastases (P less than 0.01) and the hormone receptor status (P less than 0.01) resulted in significantly different survival curves for overall survival, not one of the lymphocyte subset infiltrats correlated significantly which overall survival. For disease-free survival, pT stage (P less than 0.01) and nodal (P less than 0.01) and hormone receptor status (P less than 0.05) proved to be prognostically important. However, disease-free survival was not influenced by the infiltration of any lymphocyte subset.

Cytotoxic potential despite impaired activation pathways in T lymphocytes infiltrating nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is an epithelial tumor consistently associated with EBV. The histological picture is characterized by a strikingly abundant lymphocytic infiltrate. Furthermore, the epithelial tumor cells present several immunological characteristics which suggest an important role for tumor-infiltrating lymphocytes (TIL) in the biology of this tumor. The present study reports the phenotypic and functional characterization of TIL from NPC obtained after enzymatic digestion of 15 NPC biopsies. Flow cytometric analysis of TIL suspensions indicated that most TIL were mature CD3+ T lymphocytes (mean = 60%) with a variable CD4/CD8 ratio. Most TIL were TCR alpha/beta-positive (mean = 55%) and only a few TCR gamma-delta-positive cells could be identified. A small percentage (mean = 9%) displayed an activated phenotype (CD25+, HLA class II+). Using limiting dilution analysis, we found that the average frequency of proliferative T-lymphocyte precursors (PTL-P) is lower among TIL (1/40) than in autologous (1/7) or normal PBL (1/1.4). Moreover, sorting experiments have shown that this defect is significantly more pronounced in the CD8+ than in the CD4+ TIL subset. Accordingly, the TCR and the CD2-mediated antigen-independent pathways of activation were impaired. Different types of cytotoxic precursor could be detected. These included lectin-dependent cell cytotoxicity (LDCC) and NK-like or lymphokine-activated killer (LAK) activity. Interestingly, some TIL from NPC were able to lyse an NPC tumor (C15) maintained in nude mice. Thus, despite impaired activation pathways, the cytolytic potential of proliferating TIL in NPC is preserved.

Ultrastructure of IL2-stimulated tumor-infiltrating lymphocytes showing cytolytic activity against tumor cells

Tumor-infiltrating lymphocytes (TIL) obtained from tumor tissue and pleural effusion of breast carcinoma were cultured with interleukin-2 (IL2) and thus activated. The ultrastructure of TIL stimulated by IL2 to kill various breast carcinoma cells was then investigated. Freshly isolated TIL cultured with autologous tumor cells for 48 h without IL2 were small, round and showed neither binding to nor killing of tumor cells. TIL stimulated to proliferate by IL2 became effector cells and showed cytotoxicity against tumor cells. Ultrastructurally, the effector TIL resembled large granular lymphocytes, and adhered to tumor cells through interdigitation or close apposition of the two plasma membranes accompanied by spot-like close membrane contacts. At the site of each spot-like contact, there was a 5-nm intercellular space. The morphology of the TIL processes did not differ from those of LAK and other CTL or NK cell processes during contact, invagination or the killing of target cells. The granules in TIL were considered to participate in the cytotoxic effect. Phenotypically heterogeneous TIL, CD8+/CD57- and CD8+/CD57+, adhered to autologous tumor cells and MCF7 (human breast carcinoma cell line). However, it was unclear which cell or cells acted as the effector for tumor-cell killing.

Factors influencing the establishment of tumour-infiltrating lymphocyte cultures from human breast carcinoma and colon carcinoma tissue

Tumour-infiltrating lymphocytes (TIL) were obtained from breast and colon tumour tissue and cultured in vitro in the presence of recombinant human interleukin-2. Seven of 35 breast tumours and five of 41 colon TIL cultures were established in vitro: proliferation rates of greater than 10(3) were achieved. The cytotoxic capacity of these cells was determined against the cell lines K562 and SW742, and percentage cytotoxicity levels of greater than 97% and 79%, respectively, were seen. An inverse relationship between the ability of TIL to kill and their proliferative capacity was observed in all cultures. The prominent phenotype was CD3 positive, with greater than 55% of TIL expressing this antigen; there was no expression of CD16. The expression of CD56 and CD25 varied, being maximumly expressed on 64% and 38% of TIL, respectively. When greater than 90% of TIL expressed CD3, the ability of the culture to kill the target cell lines was low; only when there was an increase in the proportion of cells expressing CD56 and a decrease in the expression of CD3 was there high cytotoxicity. This study indicates that the TIL which proliferate in vitro in the presence of interleukin-2 are not necessarily the mediators of cytotoxicity.

Augmentation of interleukin-2-induced activation of human melanoma tumor-infiltrating lymphocytes by heteroconjugate antibody

Heteroconjugate (HC) antibody (anti-CD3 mAb x anti-p97 melanoma mAb) or monomeric anti-CD3 mAb by itself did not induce proliferation of uncultured melanoma tumor-infiltrating lymphocytes (TILs). They also failed to induce IL-2 production in uncultured TILs, although anti-CD3 mAb, but not HC antibody, stimulated IL-2 production in peripheral blood mononuclear cells (PBMCs). Sequential treatment of uncultured TILs from p97-antigen-positive (p97+) melanomas with HC antibody, followed by washing and incubation with interleukin-2 (IL-2), induced significantly higher proliferation than incubation with IL-2 alone. HC antibody pretreatment led to significantly greater results than with anti-CD3 mAb at a 1 ng/ml level in IL-2-induced proliferation of TILs from p97+ melanomas, similar to those with anti-CD3 mAb at a level of 100 ng/ml. HC antibody (1 ng/ml) pretreatment did not enhance IL-2-induced proliferation of either TILs from p97- melanomas or PBMCs, while anti-CD3 mAb enhanced the proliferation of TILs from some p97- melanomas and PBMCs. Regardless of the pretreatment of uncultured TILs with HC antibody or anti-CD3 mAb, IL-2-activated TILs were cytotoxic primarily only to autologous tumor cells, and their phenotypes remained the same. Thus, HC antibody can augment IL-2-induced activation of TILs only from p97+ melanomas, without altering their pattern of cytotoxicity or phenotype. The findings were consistent with observations at the clonal level. In contrast to anti-CD3 mAb, HC pretreatment of uncultured TILs from only p97+ melanoma prior to limiting-dilution analysis increased the number of proliferating TIL clones, including autologous tumor-specific cytotoxic T lymphocyte clones. These results suggest that use of HC antibody in vivo would be more advantageous than anti-CD3 mAb, with regard to augmentation of IL-2-induced TIL activation.

Effects of cytokines on in vitro growth of tumor-infiltrating lymphocytes obtained from human primary and metastatic liver tumors

Tumor-infiltrating lymphocytes (TIL) were isolated from 22 human primary and metastatic liver tumors, and expanded in vitro in the presence of either interleukin-2 (IL-2, 100 U/ml) plus tumor necrosis factor alpha (TNF alpha, 1000 U/ml), IL-2 (1000 U/ml) plus IL-4 (1000 U/ml) or IL-2 (1000 U/ml) alone. TIL proliferated in culture in 20/22 cases. Among different cytoline combination, TNF alpha and IL-2 were most effective in promoting the outgrowth of CD3+CD8+T lymphocytes (mean +/- SEM: 90% +/- 5) in the cultures of TIL from primary liver tumors. Cytotoxicity against autologous tumor cells was demonstrated in all early cultures of TIL from primary liver cancers in the presence of IL-2 plus TNF alpha. In contrast, cultures of TIL derived from colon cancer metastatic to liver had significantly lower levels of autotumor cytotoxicity and proportions of CD3+CD8+ cells (40% +/- 13) than those of TIL from primary liver tumors. The addition on day 0 of interferons (alpha or gamma) to TIL cultured in the presence of TNF alpha and IL-2, significantly augmented cytotoxicity against autologous tumor. In contrast, incubation of TIL in the presence of IL-4 and IL-2 did not result in increased autotumor responses in the cultures of TIL from primary liver tumors. The expansion (-fold) of TIL (day 30) cultured in the presence of IL-2 alone compared to that in the presence of TNF alpha and IL-2 was significantly greater for hepatocellular carcinoma (median, 280 vs 260) than for autologous peripheral blood lymphocytes (36 vs 27), cholangiocarcinoma (42 vs 51) or TIL from metastatic colon cancer (39 vs 30). Outgrowth of TIL in IL-2 plus TNF alpha offers an opportunity for in vitro enrichment in cells with autotumor cytotoxicity in primary liver tumors. However, this cytokine combination was unable to promote and sustain growth of autotumor effectors from TIL in metastatic liver cancer.

Clonal analysis of tumor-infiltrating lymphocytes from human primary and metastatic liver tumors

Phenotypic and functional characteristics of tumor-infiltrating lymphocytes (TIL) obtained from human primary and metastatic liver tumors were studied. Lymphocytes isolated from 18 tumors and autologous (A) peripheral blood (6 cases) were phenotyped by 2-color flow cytometry and cloned in a limiting dilution system, which allows virtually all normal T lymphocytes to proliferate; 70-80% of fresh TIL were T cells (i.e., CD3+), and the ratio of CD4+/CD8+ cells was 1.2 in both primary and metastatic liver tumors. TIL contained significantly more CD56+ (NKHI+) cells, half of which were CD3+CD56+, CD3+CD25+ cells and CD3+HLA-DR+ cells, than A-PBL. The frequencies of proliferating T-cell precursors (PTL-p) and cytolytic T-lymphocyte precursors (CTL-p) reactive with K562, allogeneic tumor cells and autologous tumor cells, were determined. Mean PTL-p frequencies for TIL from hepatocellular carcinomas, cholangiocarcinomas and metastatic liver tumors were 0.52 (0.22-0.83), 0.10 (0.05-0.16) and 0.16 (0.01-0.30), respectively. The frequency of CTL-p with natural-killer-like activity was lower in TIL than in A-PBL. The frequency of CTL-p for autologous tumor cells in fresh TIL isolated from primary liver tumors was 0.02-0.13 and 12/81 clones were reactive against autologous tumor. In contrast, only 1/66 TIL clones obtained from colon carcinomas metastatic to liver showed autotumor reactivity. No clones reactive with autologous tumor were obtained from peripheral blood of patients with liver cancer. These data indicate that substantial differences in anti-tumor functions of TIL between primary and metastatic liver tumors exist, which can be detected at a clonal level.

Principal lymphocyte subpopulation in local host response to human oesophageal cancer

We investigated what subpopulations of tumour-infiltrating lymphocytes (TIL) play a key role in in vivo function and what determines the degree of local host response represented by lymphocyte infiltration in human oesophageal cancer. We examined the increased subpopulation of TIL in "good responders" (GR) (patients with intensively TIL infiltrated tumours) when compared with "poor responders" (PR) (patients with weakly TIL infiltrated tumours). The frequency of each subpopulation was determined by quantitative flow-cytometric measurement on TIL separated from fresh tumours. Of TIL in GR, the frequency of CD3+ cells increased significantly (P less than 0.05) but the frequencies of CD16+, Leu7-, and CD16+ Leu7- cells were low and did not increase significantly compared with those in PR. With respect to T-cell subsets of TIL in GR, the frequency of CD8+ cells was significantly higher than that in PR (P less than 0.01), and CD4+/CD8+ ratio was lower than that in PR (P less than 0.025). On two-colour analyses, most of CD8+ cells (cytotoxic/suppressor T-cells: Tc/s) did not co-express CD11b and the frequency of CD8+ CD11b- cells (cytotoxic T-cell: Tc) increased significantly compared with that in PR. Clinicopathological and phenotypic analysis of peripheral blood lymphocytes revealed that there are no major differences in general immunocompetence between GR and PR. These results suggest that Tc/s, especially Tc, might play a key role in local host response. They also suggest that not only the general immune status of the host but also the identification of class I major histocompatibility complex antigens by the host at the tumour site may strongly affect the degree of host response in oesophageal cancer.

Emergence of a dominant cytotoxic T lymphocyte antitumor effector from tumor-infiltrating cells in the anterior chamber of the eye

Previous studies in mice revealed that resolving intraocular tumors (UV5C25 fibrosarcoma) were infiltrated with mononuclear cells and invoked potent systemic delayed-type hypersensitivity responses without nonspecific tissue destruction. The present study characterized the tumor-infiltrating lymphocyte (TIL) population and established its role as the mediator of specific intraocular tumor rejection. This was accomplished by (a) isolating TIL from resolving intraocular tumors; (b) identifying characteristic surface markers on TIL; and (c) demonstrating in vitro and in vivo antitumor functions. Fluorescence-activated cell sorter analysis of TIL showed 33.4% Thyl+, 19.8% CD8+, 11.1% CD4+, 17.2% MAC-1+, 10.4% F4/80+, and 7.7% B220+. Functional studies indicated that TIL were directly cytolytic for UV5C25 tumor cells. Additionally a tumor-necrosis-factor(TNF)-sensitive cell line (WEHI 164.1) was lysed on cocultivation with TIL, whereas UV5C25 tumor cells were insensitive to lysis by TNF. Precursor CTL analysis demonstrated a high frequency (1/251) of tumor-specific precursors and a low frequency of alloresponsive cells in the TIL population. In vivo analysis by a Winn-type assay demonstrated that only TIL could effect tumor resolution in immunosuppressed hosts. These results demonstrate that although CD4+ T cells and macrophages were present and TNF activity was detected in the TIL population, there was no evidence for nonspecific tissue destruction within the eye. Therefore, this pattern of intraocular tumor rejection is mediated by a lymphocyte population expressing cell-surface phenotypes and functional characteristics of conventional cytotoxic T lymphocytes. Moreover, the results suggest that a regulatory mechanism within the eye allows for the emergence of one dominant antitumor effector (CTL) while controlling a more destructive mechanism (delayed-type hypersensitivity).

Sparse distribution of gamma/delta T lymphocytes around human epithelial tumors predominantly infiltrated by primed/memory T cells

Evidence from the mouse system has suggested that T lymphocytes accumulating in non-lymphoid tissue, in particular epithelia, may preferentially express the T cell receptor (TCR) gamma delta. In this study, we characterize the T cell receptor alpha beta or gamma delta phenotype of lymphocytes infiltrating human tumors of epithelial origin using monoclonal antibodies (mAb) for immunohistology and flow cytometry on cells extracted by enzyme digestion. This report shows that the majority of CD3+ tumor-infiltrating lymphocytes are TCR alpha beta+ but a small percentage of TCR gamma delta can be clearly defined scattered throughout the tumor tissue with apparently no microanatomical selection. So far there has been little evidence for an accumulation of activated T cells in human tumor tissues as defined by mAb against molecules appearing transiently during the acute phase of activation. Now mAb are available that can identify primed or memory T cells such as mAb UCHL-1 recognizing the CD45RO antigen. Here we show that CD3+ tumor-infiltrating lymphocytes have a statistically significant accumulation of primed T cells, as compared to the autologous peripheral blood lymphocytes, suggesting their immune stimulation by tumor cells.

Tumor-infiltrating lymphocytes from nonrenal urological malignancies

Tumor-infiltrating lymphocytes (TIL) were isolated from 15 of 20 surgical specimens of transitional cell carcinoma of the urinary bladder, prostate cancer, testicular cancer, Wilms tumor and adrenal cancer. Expansion was carried out in four different culture conditions, each containing 1000 U/ml interleukin-2: RPMI medium with or without 20% (by volume) of lymphokine-activated killer cell (LAK) supernatant and AIM V medium with or without 20% LAK supernatant. The resultant cell populations were then assayed for cytotoxicity against a variety of autologous and allogeneic tumor targets and phenotypic analysis was performed with fluorescein-labeled monoclonal antibodies. TIL growth was unrelated to the initial percentage of lymphocytes or tumor cells present in the enzymatically dispersed specimens or whether fresh or cryopreserved tissue was utilized. Better growth was seen in AIM V than in RPMI medium (P = 0.013); the beneficial effect of the addition of LAK supernatant to RPMI was indicated (P = 0.065), and the addition of LAK supernatant to AIM V did not improve the ability to culture TIL (P = 0.5) from these cancers. TIL in long-term culture were predominantly CD3+. The ratio of CD4+/CD8+ cells varied with time in culture and culture medium, but most cultures eventually became CD4+. Cells bearing B cell, natural killer cell, and macrophage markers disappeared early in culture. Overall 14/15 TIL samples were lytic against one of the autologous and allogeneic targets tested, but specific lysis against the autologous tumor from which it was derived was seen in only one TIL culture originating from a bladder cancer. Our results suggest that TIL can be expanded to therapeutic levels from a variety of urological malignancies and that their potential role in future therapy should be further explored.

What's new in the local immune response in cancer?

Malignant tumors in humans are commonly associated with an inflammatory infiltrate. The mechanisms that account for the accumulation of T-lymphocytes and macrophages--these cells comprise the major components of tumor infiltrates--in the vicinity of a growing tumor are not fully understood. Tumor specific and immunogenic antigens could not be demonstrated in most solid tumors of humans, in contrast to several experimental tumor models. Thus it is not proven in human malignancies that neoantigens expressed on malignant cells are the signal which initiates an inflammatory response that, immunohistologically, is comparable to mononuclear infiltrates present in allograft rejection. A variety of nonspecific factors including lymphokines released by tumor cells may also account for the accumulation of inflammatory cells at the tumor site. The difficulties to evaluate the functional role of the "local immune response" for tumor and host are even greater. Most tumors progress in the presence of mononuclear infiltrates. Do they progress in spite of or because of the action of the local immune response? Clinical, immunopathological, and experimental data suggest that both is right, and that at least four distinct properties of tumor-associated immune reactions exist: Regression, Selection, Modulation and Progression. These distinct properties will be discussed below, using mainly the malignant melanoma of the skin as a model for a malignant tumor in humans.