Lymphocytes infiltrating human breast cancers lack K-cell activity and show low levels of NK-cell activity

Worse outcome in breast cancer with higher tumor-infiltrating FOXP3+ Tregs : a systematic review and meta-analysis

Background

Forkhead box P3(FOXP3) is known as the optimum maker for regulatory T cells(Tregs), which are conventionally thought to induce immune tolerance to disturb the antitumor immunity. However, the research on the prognostic significance of tumor-infiltrating FOXP3+ Tregs in breast cancer is still limited and the results are controversial.

Methods

We searched for studies in PubMed, EMBASE and Web of Science prior to January 2015. The correlation between FOXP3+ tumor-infiltrating lymphocytes(TILs) and breast cancer prognosis was analyzed. The meta-analysis was performed using STATA 11.0. Pooled hazard ratios (HRs) with 95 % confidence intervals (CIs) were used to estimate the degree of the association between FOXP3+ TILs and prognosis of breast cancers, while relative ratios (RRs) were used to evaluate the relationship between FOXP3+ TILs and clinicopathological features of breast cancers.

Result

A total of 15 studies comprising 8666 breast cancer patients met the inclusion criteria. Our results showed that higher FOXP3+ TILs level was significantly associated with poor prognosis in terms of overall survival (OS) (pooled HR:1.60, 95 % CI:1.06–2.42; P < 0.05). We found that breast cancer with higher FOXP3+ TILs level was positively correlated with c-erbB-2 positive status (pooled RR:1.52, 95 % CI:1.32–1.75; P < 0.05), lymph node positive status(pooled RR:1.17, 95 % CI:1.04–1.32; P < 0.05) while there was a negative association with ER positive status(pooled RR:0.65, 95 % CI:0.56–0.76; P < 0.05) and PR positive status(pooled RR:0.66, 95 % CI:0.51–0.87; P < 0.05).

Conclusion

The present results of meta-analysis showed that higher FOXP3+ TILs level in patients with breast cancer led to poor overall survival (OS) and was significantly associated with c-erbB-2 status, lymph node status, ER status and PR status. FOXP3+ TILs level is a promising prognostic factor in breast cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2732-0) contains supplementary material, which is available to authorized users.

Natural killer (NK) cell profiles in blood and tumour in women with large and locally advanced breast cancer (LLABC) and their contribution to a pathological complete response (PCR) in the tumour following neoadjuvant chemotherapy (NAC): differential restoration of blood profiles by NAC and surgery

Background

NK cells contribute to tumour surveillance, inhibition of growth and dissemination by cytotoxicity, secretion of cytokines and interaction with immune cells. Their precise role in human breast cancer is unclear and the effect of therapy poorly studied. The purpose of our study was to characterise NK cells in women with large (≥3 cm) and locally advanced (T3–4, N1–2, M0) breast cancers (LLABCs) undergoing neoadjuvant chemotherapy (NAC) and surgery, and to ascertain their possible contribution to a pathological complete response (pCR).

Methods

Women with LLABCs (n = 25) and healthy female donors [HFDs (n = 10)] were studied. Pathological responses in the breast were assessed using established criteria. Blood samples were collected pre and post NAC and surgery. Flow cytometry and labelled monoclonal antibodies established absolute numbers (AbNs) and percentages (%) of NK cells, and expressing granzyme B/perforin and NKG2D. In vitro NK cytotoxicity was assessed and NK cells and cytokines (IL-2, INF-γ, TGF-β) documented in tumours using immunohistochemical techniques. Data was analysed by SPSS.

Results

Women with LLABCs had significantly reduced AbNs (160.00 ± 40.00 cells/µl) but not % of NK cells, compared with HFDs (NK: 266.78 ± 55.00 cells/µl; p = 0.020). NAC enhanced the AbN (p = 0.001) and % (p = 0.006) of NK cells in patients with good pathological responses. Granzyme B⁺/perforin⁺ cells were significantly reduced (43.41 ± 4.00%), compared with HFDs (60.26 ± 7.00%; p = 0.003). NAC increased the % in good (p = 0.006) and poor (p = 0.005) pathological responders. Pretreatment NK cytotoxicity was significantly reduced in good (37.80 ± 8.05%) and poor (22.80 ± 7.97%) responders (p = 0.001) but remained unchanged following NAC. NK-NKG2D⁺ cells were unaltered and unaffected by NAC; NKG2D expression was increased in patients with a pCR (p = 0.001). Surgery following NAC was not beneficial, except in those with a pCR. Tumour-infiltrating NK cells were infrequent but increased peritumourally (p = 0.005) showing a significant correlation (p = 0.004) between CD56⁺ cells and grade of response. Tumour cytokines had no effect.

Conclusion

Women with LLABCs have inhibited blood innate immunity, variably reversed by NAC (especially with tumour pCRs), which returned to pretreatment levels following surgery. These and in situ tumour findings suggest a role for NK cells in NAC-induced breast pCR.

Histamine dihydrochloride: inhibiting oxidants and synergising IL-2-mediated immune activation in the tumour microenvironment

The potential role of histamine in cancer immunotherapy has been a subject of interest for more than a decade. A significant body of research has elucidated the action of histamine in a model system that mimics the tumour microenvironment. In vitro evidence indicates that histamine inhibits the generation and release of reactive oxygen species (ROS) by monocytes/macrophages (MO) during respiratory burst. Since ROS have been shown to abrogate peritumoural and intratumoural cytokine activation of natural killer (NK) and T-cells and induce apoptosis of these cells in vitro, inhibition of ROS may enable cytokines to activate NK and T-cells and restore their antineoplastic, cytotoxic capabilities. Experimental data indicate that histamine and interleukin-2 (IL-2) act synergistically to activate NK cell cytotoxicity (NKCC). Although IL-2, a regulator of immune responses, has been shown to promote NKCC in monotherapy for metastatic melanoma (MM), renal cell carcinoma (RCC) and acute myeloid leukaemia (AML), objective responses occur in a minority of patients and survival is not significantly extended, except for a minority of patients with MM using high-dose regimens which have not been widely adopted. In vitro findings suggest that the addition of histamine to IL-2 therapy might improve response rates and disease-free survival by protecting the cells of the immune system from oxidative stress and inducing natural endogenous immune cytotoxicity. An IL-2/histamine Phase III trial is in progress in a population of AML patients. A recently completed Phase III trial of IL-2 vs. IL-2/histamine in patients with MM demonstrated a trend towards a superior survival benefit from IL-2/histamine for all patients entered, and a statistically significant survival benefit for patients with hepatic metastases.

Computerised counting of tumour infiltrating lymphocytes in 90 breast cancer specimens

Tumour infiltrating lymphocytes (TILs) implicated in immunologic cytotoxicity were evaluated by immunohistochemistry and digitally counted in serial sections from 90 breast cancers in order to assess their number, the relationships between them and to tumour histology. CD3+, CD4+, CD8+, CD20+, CD25+ and CD56+ lymphocytes were found in 58 (64.4%), 52 (57.7%), 50 (55.5%), 22 (24.4%), 11 (12.2%) and 21 (23.3%) tumours, respectively. There was no difference in the number of TILs between pure infiltrating ductal (NOS) and non-ductal carcinomas, and no relationship between TILs and histological grades was found. CD3+ TILs directly correlated to age, while lymph node negative patients had tumours infiltrated by fewer CD4+ TILs with respect to lymph node positive patients. In 25/90 patients, randomly chosen, the status of peripheral blood lymphocytes was evaluated but no differences with respect to the status found in healthy blood donors was obtained; nonetheless while in some patients CD8+ TILs outnumbered CD4+ TILs in situ, the CD4/CD8 ratio was normal in their peripheral blood. The results show a considerable diversity of TILs among breast tumours, their lack of relationship with the status of the peripheral blood cells, and their potential important relationship with age (CD3+) and lymph node status (CD4+).

Histamine in human breast cancer

BACKGROUND

Histamine inhibits lymphocyte function in vitro at concentrations of greater than 10(-6) mol/l. The aim of this study was to determine whether histamine concentrations in breast cancers were sufficient to produce an immunological effect.

METHODS

Tumour and adjacent normal breast content of histamine was measured using a radioenzymatic assay in 29 patients having surgery for breast cancer.

RESULTS

The median content of histamine in breast cancer tissue was 5.4 (range 0.9-27.3) microg/g (median concentration 4.5 x 10(-5) mol/l), and was significantly greater than that in adjacent breast tissue (P = 0.007).

CONCLUSION

The concentration of histamine in breast cancer was sufficient to inhibit lymphocyte function and could be locally immunosuppressive.

Expression and prognostic significance of HLA class I, ICAM-1, and tumor-infiltrating lymphocytes in esophageal cancer

Most solid malignancies show some degree of lymphoid infiltration suggesting a specific immunologic host vs. tumor reaction. Tumor-infiltrating lymphocytes (i.e., CD3 + T-lymphocyte subsets), the human leukocyte antigen (HLA) class I molecules, and the intercellular adhesion molecule-1 (ICAM-1) are key factors involved in T-cell-mediated immune surveillance. The present study was designed to assess the expression pattern of intratumoral lymphocyte infiltrates and their relationship to HLA class I and ICAM-1 expression with regard to primary esophageal carcinoma and to evaluate their prognostic influence. Representative samples of primary tumors were obtained from 55 patients who had undergone radical en bloc esophagectomy. Frozen sections of these tumors were stained with monoclonal antibodies directed against CD3 for the assessment of tumor-infiltrating lymphocytes, HLA class I, and ICAM-1. The mean postoperative observation period was 19.5 months (range 5 to 45 months). Lymphocyte infiltration was absent in four tumors (8%), whereas 31 tumors (64%) showed moderate and 13 (27%) showed strong infiltration. HLA class I expression was deficient in 24 tumors (45%). Coexpression of HLA class I and ICAM-1 was significantly associated with lymphocyte infiltration of the tumor. Kaplan-Meier analyses revealed a significant beneficial influence on relapse-free survival for patients with lymphocyte infiltration of primary tumors compared to those with no lymphocyte infiltration of tumors (median 4 months vs. 18 months; P <0.002) and for HLA class I+ tumors compared to HLA class I- tumors (median survival >18 months vs. 7 months; P = 0.0081). The present data support the hypothesis that T-cell-mediated immunity may influence the fate of patients with esophageal cancer.

Natural killer cells and cancer

BACKGROUND

Natural cytotoxicity, mediated by natural killer (NK) cells and cell with lymphokine-activated killer (LAK) activity, is believed to play an important role in host anti-cancer mechanisms.

METHODS

The authors critically review recent publications on the role of natural cytotoxicity in patients with cancer.

RESULTS

In patients with cancer, several studies have noted variations in the numbers and activity of NK and cells with LAK activity in different body compartments. NK cell activity in the peripheral blood lymphocytes (PBLs) is higher than that found in lymph nodes and within tumors, and this appears to be due to the presence of suppressor factors. The natural cytotoxicity of PBLs in patients with different types of cancers varies. However, there appears to be a trend for natural cytotoxicity to be reduced in certain cancer patients, possibly related to tumor volume or dissemination. Anti-cancer treatments (e.g., surgery, hormonal modulation, radiotherapy and chemotherapy) can also result in suppression of natural cytotoxicity, although the long-term effect on response to treatment and development of metastases is at present unknown.

CONCLUSIONS

NK and LAK cells, through the use of immune biologic modifiers, have been demonstrated to have a therapeutic role in the treatment of human cancers. Further studies are required to determine the optimal dosages and combinations of chemotherapeutic agents, the timing of surgery, and the adjuvant use of immune biologic response modifiers. An increasing awareness and understanding of this field, may allow for the future development of anti-cancer therapies.

In vivo trafficking of adoptively transferred interleukin-2 expanded tumor-infiltrating lymphocytes and peripheral blood lymphocytes. Results of a double gene marking trial

Adoptive immunotherapy with tumor-infiltrating lymphocytes (TIL) and IL-2 appears to produce dramatic regressions in patients with metastatic melanoma and renal cancer. However, the in vivo mechanism of TIL function is not known. We conducted an UCLA Human Subject Protection Committee, Recombinant DNA Advisory Committee, and FDA-approved clinical trial using genetically-marked TIL to test the hypothesis that these cells have unique, tumor-specific in vivo trafficking patterns. TIL and PBL (as a control effector cell population) were isolated and expanded in parallel in vitro in IL-2-containing medium for 4-6 wk. During the expansion, TIL and PBL were separately transduced with the amphotropic retroviral vectors LNL6 and G1Na. Transduced TIL and PBL were coinfused into patients and their respective numbers measured in tumor, peripheral blood, and normal tissues; integrated provirus could be quantitated and distinguished by DNA PCR. Nine patients were treated (six melanoma, three renal) and received between 4.5 x 10(8) and 1.24 x 10(10) total cells. Both "marked" TIL and PBL could be detected circulating in the peripheral blood, in some patients for up to 99 d after infusion. Marked TIL and/or PBL could be detected in tumor biopsies in six of nine patients as early as day 6 and as late as day 99 after infusion. No convincing pattern of preferential trafficking of TIL vs. PBL to tumor was noted. Moreover, concurrent biopsies of muscle, fat, and skin demonstrated the presence of TIL/PBL in comparable or greater numbers than in tumor in five patients. The results of this double gene marking trial provide interesting insights into the life span and trafficking of adoptively transferred lymphocytes, but do not support the hypothesis that TIL specifically traffic to tumor deposits.

Potential role of natural killer cells in controlling tumorigenesis by human T-cell leukemia viruses

Human T-cell leukemia virus (HTLV) is the etiologic agent of adult T-cell leukemia (ATL), a malignancy of T lymphocytes that is characterized by a long latency period after virus exposure. Intraperitoneal inoculation of severe combined immunodeficient (SCID) mice with HTLV-transformed cell lines and ATL tumor cells was employed to investigate the tumorigenic potential of HTLV type I (HTLV-I)-infected cells. In contrast to inoculation of ATL (RV-ATL) cells into SCID mice, which resulted in the formation of lymphomas, inoculation of HTLV-I- and HTLV-II-transformed cell lines (SLB-I and JLB-II cells, respectively) did not result in tumor formation. Immunosuppression of SCID mice, either by whole-body irradiation or by treatment with an antiserum, anti-asialo GM1 (alpha-AGM1), which transiently abrogates natural killer cell activity in vivo, was necessary to establish the growth of tumors derived from HTLV-transformed cell lines. PCR and flow cytometric studies reveal that HTLV-I-transformed cells are eliminated from the peritoneal cavities of inoculated mice by 3 days postinoculation; in contrast, RV-ATL cells persist and are detected until the mice succumb to lymphoma development. The differing behaviors of HTLV-infected cell lines and ATL tumor cells in SCID mice suggest that ATL cells have a higher tumorigenic potential in vivo than do HTLV-infected cell lines because of their ability to evade natural killer cell-mediated cytolysis.

CD4+ T lymphocytes infiltrating human breast cancer recognise autologous tumor in an MHC-class-II restricted fashion

Tumor-infiltrating lymphocytes (TIL) were derived from primary breast tumors, metastatic lymph nodes and malignant pleural effusions from 34 patients with breast cancer. TIL were cultured for approximately 30 days and studied for phenotype, cytotoxicity, and the ability to secrete cytokines in response to autologous tumor stimulation. Tumor specimens were obtained from two different sites in 7 patients, resulting in 41 samples from which 38 TIL cultures were established. In addition to screening 38 bulk TIL cultures, TIL from 21 patients were separated into CD4+ and CD8+ subsets and extensively studied. Three CD4+ TIL were found specifically to secrete granulocyte macrophage-colony-stimulating factor and tumor necrosis factor alpha when stimulated by autologous tumor and not by a large panel of stimulators (24-34) consisting of autologous normal cells, allogeneic breast or melanoma tumors and EBV-B cells. This cytokine release was found to be MHC-class-II-restricted, as it was inhibited by the anti-HLA-DR antibody L243. These 3 patients' EBV-B cells, when pulsed with tumor lysates, were unable to act as antigen-presenting cells and induce cytokine secretion by their respective CD4+ TIL. These findings demonstrate that MHC-class-II-restricted CD4+ T cells recognising tumor-associated antigens can be detected in some breast cancer patients.

Natural immunity in breast cancer patients during neoadjuvant chemotherapy and after surgery

Breast cancer is the most common cancer in women. Surgery, and more recently neoadjuvant chemotherapy, are being utilized as the initial treatment for breast cancer; however little is known about their effects on the natural immune system. The natural immune system (natural killer [NK] cells) is thought to be important in immune surveillance, including protection from metastasis during the intravascular tumour seeding that occurs during surgery. To investigate the effects of surgery on the natural immune system, we studied the pre-operative and post-operative peripheral blood lymphocytes (PBL) of 10 patients with stage I or II breast cancer: there was a 71.6 +/- 25.3% post-operative reduction in NK cell function (P < 0.005, Student's paired t-test). To investigate the effects of neoadjuvant chemotherapy and surgery, we examined PBL from five patients with stage III breast cancer: NK cell function dropped 95.7 +/- 1.9% after neoadjuvant chemotherapy, and there was a further 51.0 +/- 23.4% decrease after surgery (P < 0.05, Student's paired t-test). Neither group of patients had decreased numbers of NK cells, changes in the percentage of T helper or suppressor cells, or alterations in the production of cytotoxic factor by NK cells. These findings suggest that the impairment in NK cell function reflects a defect in the ability of NK cells to recognize and/or bind to tumour target cells. We conclude that the initial treatment of breast cancer patients, whether it involves surgery alone or with neoadjuvant chemotherapy, profoundly impairs their natural immune system and could increase the risk of metastasis. Further studies are needed to delineate the mechanism of this derangement in natural immunity and possibly alter its course.

Isolation and expansion of lymphocytes from gastrointestinal tumour tissue

Adoptive cellular immunotherapy (ACI) with tumour-infiltrating lymphocytes (TIL) has met with some success in patients suffering from malignant melanoma. However, the success of this approach hinges on the successful isolation and in vitro expansion of TIL. Viable, IL-2 responsive TIL were obtained from only two of five gastrointestinal primary or 'non-lymph node' secondary gastrointestinal tumours. In contrast, proliferating TIL were successfully expanded from four out of five lymph node secondary deposits from gastrointestinal cancer patients, but these TIL were non-cytolytic. Conversely, proliferating lymphocytes were generated from six out of seven malignant effusions from gastrointestinal cancer patients in the late phase of their disease. Despite the presence of effective anti-tumour cytotoxic activity in one such culture, these lymphocytes failed to proliferate sufficiently for potential clinical use. Consequent upon these findings, we are sceptical that ACI using mononuclear cells infiltrating primary or secondary sites from patients with gastrointestinal cancer will be feasible.

Hyaluronan (hyaluronic acid) and hyaluronectin in the extracellular matrix of human breast carcinomas: comparison between invasive and non-invasive areas

We performed quantitative determination of the distribution of hyaluronan (hyaluronic acid, HA) and the HA-binding protein, hyaluronectin (HN), 2 components of the extracellular matrix of tumor desmoplasia, within 71 human breast carcinomas. Results showed that HA and HN were more elevated in tumoral than in non-tumoral adjacent tissue, and that the peripheral invasive area of tumors contained increased levels of HA and HN as compared with the central non-invasive area (p less than 10(-3) and p less than 10(-5) respectively). HN and HA levels of 61 ductal carcinomas were related to the histological grade of tumors; no significant difference was found between grades for HA; HN was found to be significantly lower in grade III than in grade II tumors (p less than 0.01). HA and HN rates were correlated in grade I and grade II tumors and were not correlated in grade III. Mean percentage of HA saturation level by HN for whole tumors was found to be less than 4%, indicating that HA is essentially free of proteins and could be used as a target for cancer diagnosis or therapy.

Human NK cells in health and disease: clinical, functional, phenotypic and DNA genotypic characteristics

Natural killer (NK) cells are the subject of great current interest because of their possible (in vivo) role in tumour cell surveillance and killing, and because of the potential application of cytokine-modulated NK cells in cancer immunotherapy. In addition, clonal proliferations of NK-associated (NKa) cell populations represent a high proportion of chronic (non-B) lymphoid malignancies and abnormal (both clonal and non-clonal) NKa components are being increasingly reported in association with diverse clinical pictures such as autoimmune disease. This communication extensively reviews what is presently known regarding normal and leukaemic NKa phenotypic diversity, the mechanisms of NK-mediated cytolysis, the role of NK cells in malignancy, and the diagnostic and cellular aspects of malignant NKa proliferations.

Variable natural killer function of tumour-infiltrating lymphocytes from breast carcinomas

Samples were obtained from 36 breast cancer patients: 24 tissue samples from carcinomas, six samples from non-cancerous breast tissue and 22 samples of peripheral blood (PB). Natural killer (NK) activity was tested against the classical target K-562 and the breast carcinoma cell line T-47D, using a microcytotoxicity assay measuring inhibition of uptake of 3H-thymidine by target cells. The active effector cells against both target cell types were identified as CD-56-positive large granular lymphocytes. PB lymphocytes from breast cancer patients showed normal NK activity against both K-562 (mean inhibition: 75.4%, controls: 78.1%) and T-47D (mean inhibition: 77.6%, controls: 78.0%). Tumour-infiltrating lymphocytes (TIL) from 24 breast carcinomas showed considerable variation in NK activity against K-562: only two cases (8%) had no activity (less than or equal to 5% inhibition), 15 cases (63%) had moderate activity (15-48% inhibition), and seven cases (29%) showed full NK activity (defined as greater than or equal to 50% inhibition). TIL from three carcinomas were also tested against T-47D and gave 21-46% inhibition. The NK activity of TIL declined with time in culture with one notable exception where there was full NK activity after seven days in culture. NK activity of TIL showed significant positive correlation with increasing degree of lymphocytic infiltration of the tumour, and correlated also with PB NK activity. No correlation was apparent with stage of disease. The NK activity was usually lower in the TIL than the PB sample when tested in parallel. This difference was probably caused by experimental conditions as well as different relative numbers of natural killer cells. In six cases tested, infiltrating lymphocytes from carcinoma and normal tissue from the same breast were found to have similar NK activities. We conclude that the non-specific cytotoxic activity of TIL from breast carcinomas covers the whole range from complete lack of function to full capacity comparable with NK activity of PB lymphocytes. The level of activity was moderately correlated with the degree of lymphoid infiltration but was not related to stage of disease. Differences in functional capacity of TIL may be of importance in predicting possible benefits from immunomodulating therapy.

Recombinant interleukin-2 treatment in patients with metastatic colorectal cancer: effect on natural cytotoxicity

Natural cytotoxicity (natural killer, NK, and lymphokine-activated killer, LAK, activity) was documented in 12 patients with metastatic colorectal cancer, both before and after a 5-day course of continuous therapy with intravenous recombinant interleukin-2 (rIL-2). Treatment induced a substantial increase in circulating CD56+ lymphocytes (pretreatment: 12.1 +/- 6.9%, mean +/- SD; posttreatment: 39.2 +/- 6.9%. Maximal NK cell activity was induced by treatment with rIL-2 but only suboptimal augmentation of LAK cell cytotoxicity was obtained. This study indicates that although continuous infusion of rIL-2 does have a significant effect on natural cytotoxicity, this is suboptimal and further studies are necessary to define the most efficacious immunity-enhancing regimens of therapy, thereby hopefully improving clinical outcome of rIL-2 treatment.

Selective homing of phenotypically lytic cells within nasopharyngeal carcinoma biopsies: numerous CD8- and CD16-positive cells in the tumor

We present a comparative analysis of cell-mediated immunity between circulating lymphocytes and tumor-infiltrating lymphocytes (TIL) from patients with nasopharyngeal carcinoma (NPC). Phenotypic analysis using a panel of monoclonal antibodies (MAbs) to define lymphocytic subsets has revealed a selective homing of phenotypically lytic cells such as CD8- and CD16-positive cells, but a low percentage of macrophages when compared to PBL of NPC patients. Also, PBL and TIL contain an equivalent percentage of activated T-lymphocytes expressing HLA-DR molecules and IL-2 receptors. Functionally, TIL exhibit an abolished NK-cell activity and concomitant decrease of proliferative response to phytohemagglutinin (PHA) and concanavalin A (ConA) stimulation when compared with PBL.

Stimulation of lymphocyte natural cytotoxicity by L-arginine

In vitro L-arginine enhanced natural-killer (NK) and lymphokine-activated-killer (LAK) cell activity; this cytotoxicity was mediated by CD56+ cells. In vivo arginine supplements (30 g/day for 3 days) increased the number of circulating CD56+ cells by a median of 32% in eight volunteers (p less than 0.01); this increase was associated with a mean rise of 91% in NK cell activity (p = 0.003) and of 58% in LAK cell activity (p = 0.001) in thirteen volunteers. These findings have potentially important implications for the modulation of natural cytotoxicity in a wide range of disease states.

Flow cytometric analysis of tumour infiltrating lymphocytes in breast cancer

In 31 patients with carcinoma of the breast the phenotype and activation status of tumour infiltrating lymphocytes (TILs) was analysed by flow cytometry. The predominant cells, in all patients, were T lymphocytes and in the majority of cases CD8+ (cytotoxic/suppressor) T lymphocytes were present in greater numbers than CD4+ (helper) T lymphocytes. There was no relationship between the degree of lymphocytic infiltration and either tumour stage or grade but there appeared to be an inverse correlation with the levels of oestrogen receptor (ER) in the tumour (P less than 0.01). Both populations of T cells had significantly higher numbers of cells carrying HLA DR (class II major histocompatibility antigen) than the equivalent populations in peripheral blood from the same patient group (P less than 0.001). The transferrin receptor was found on similar numbers of CD8+ T cells in peripheral blood and among the tumour infiltrating lymphocytes while more of the CD4+ T cells infiltrating the tumour were found to carry this receptor (P = 0.034). The Tac (CD 25) antigen was also on similar numbers of CD8+ T cells from both peripheral blood and the tumour but was on fewer of the CD4+ T cells in the tumour with respect to peripheral blood (P = 0.029). In both TILs and blood lymphocytes, the Tac antigen was consistently present on greater numbers of CD4+ T lymphocytes than on the CD8+ T lymphocytes (P less than 0.001) and as this is a component of the interleukin 2 (IL-2) receptor this may be of relevance to the use of IL-2 in TIL cancer therapy.

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).

The reactive cellular population and expression of blood group substance in human colorectal cancer

The correlation between the expression of blood group substance (BGS) and the host's immune response was studied in 23 samples of human colorectal carcinoma tissue. Several monoclonal antibodies against lymphocyte subsets and histiocytes were used for immunostaining of frozen sections, and MoAbs against BGS (A, B, H) for paraffin sections. In proximal colon cancers (10 cases), the cancer tissues showing expression of BGS revealed a greater increase in cells reactive for OKT11, Leu-7, and Leu-M3 than those with deletion of BGS. However, in distal large bowel cancers (13 cases), there was no significant difference between the cancer tissues without BGS expression and those with BGS re-expression. In all locations of the large bowel, cancer tissue showing expression of incompatible antigen revealed a greater reduction of reactive cells than those with expression of compatible antigen. These results suggest that there are disparities in the host's immune response to proximal colon and distal bowel carcinoma, and that factors other than BGS (A, B, H) might influence the immune response in cases with expression of incompatible antigen.

Biology of natural killer cells

Studies of cytotoxicity by human lymphocytes revealed not only that both allogeneic and syngeneic tumor cells were lysed in a non-MHC-restricted fashion, but also that lymphocytes from normal donors were often cytotoxic. Lymphocytes from any healthy donor, as well as peripheral blood and spleen lymphocytes from several experimental animals, in the absence of known or deliberate sensitization, were found to be spontaneously cytotoxic in vitro for some normal fresh cells, most cultured cell lines, immature hematopoietic cells, and tumor cells. This type of nonadaptive, non-MHC-restricted cellmediated cytotoxicity was defined as “natural” cytotoxicity, and the effector cells mediating natural cytotoxicity were functionally defined as natural killer (NK) cells. The existence of NK cells has prompted a reinterpretation of both the studies of specific cytotoxicity against spontaneous human tumors and the theory of immune surveillance, at least in its most restrictive interpretation. Unlike cytotoxic T cells, NK cells cannot be demonstrated to have clonally distributed specificity, restriction for MHC products at the target cell surface, or immunological memory. NK cells cannot yet be formally assigned to a single lineage based on the definitive identification of a stem cell, a distinct anatomical location of maturation, or unique genotypic rearrangements.

Tumour-associated proliferative responses in vitro of regional lymph nodes draining solid cancers in man

The proliferative responses in vitro of tumour-draining lymph node lymphocytes were evaluated against autologous colon and lung carcinoma cells. The reactivity of lymphocytes appeared to be directed against tumour-associated rather than tumour-specific antigens. The lymphocyte reactivity detected was not due to an autologous mixed lymphocyte reaction. Recombinant interleukin-2 augmented the responses detected but not their tumour specificity. Phenotypic characterisation indicated the presence of T suppressor/cytotoxic (TS/C) cells as well as natural killer (NK) cells. Only the later, however, were active in functional cytotoxicity assays. The inability to generate both tumour-specific proliferation of tumour-draining lymph node lymphocytes and tumour-specific cytotoxic killer cells may be due to the presence of suppressor cells in the regional lymph nodes; preliminary data suggest the presence of such cells.

Role of tumor-infiltrating lymphocytes in the host defense mechanism against lung cancer

Tumor-infiltrating lymphocytes (TIL) and tumor-associated macrophages (TAM) were recovered from 22 patients with primary lung cancer. The TIL did not exhibit any cytolytic activity against various target cells. The average percentage of TIL recovered was 6.7 +/- 1.3% in patients without recurrence, as compared to 3.6 +/- 0.6% in those with recurrence within 2 years after complete resection of lung cancer (P less than 0.05). The average cytostatic activity of TAM was 38.5 +/- 6.8% in patients without recurrence, although it was 25.2 +/- 4.6% in those with recurrence within 2 years after complete resection (P less than 0.1). The activity of macrophage activating factor (MAF) induced by TIL was also higher in patients showing no recurrence. A significant positive correlation was observed between MAF activity induced by TIL and the cytostatic activity of individual TAM. These results suggest that antitumor activity of TAM may be controlled by specifically sensitized TIL through lymphokines.

Tumor infiltrating lymphocytes of spontaneous versus transplanted mouse mammary tumors

Tumor infiltrating lymphocytes (TIL) were isolated by centrifugal elutriation from C4 mouse mammary tumors and characterized with regard to phenotype and natural killer (NK) activity. Tumors that had arisen spontaneously in preneoplastic hyperplastic alveolar nodules and tumors that had been passaged one to two times in either naive or presensitized mice were studied. Mice were sensitized by limited s.c. tumor growth and subsequent surgical removal of the tumor. The total numbers of T or B cells in the infiltrates were similar in spontaneous tumors and in passaged tumors from either naive or sensitized mice. The ratio of L3T4-positive to lyt-2-positive cells was reduced, however, from 1.10 +/- 0.2 in spontaneous tumors to 0.53 +/- 0.28 or 0.48 +/- 0.04 in passaged tumors from untreated or sensitized mice. The site of tumor implantation, whether intramammary fat pad or s.c., did not affect the profiles of the infiltrates. The TIL from both spontaneous and passaged tumors demonstrated enhanced NK activity relative to peripheral lymphoid cells. The TIL of passaged tumors sensitized mice, however, had lower NK activity than those from naive mice.

Identification and quantification of subsets of mononuclear inflammatory cells in melanocytic and other human tumors

We used monoclonal antibodies and an indirect immunoperoxidase technique to identify mononuclear inflammatory cells associated with human tumors. The absolute number of the different types of inflammatory cells was assessed by using a point-counting technique. We studied tissues from six primary cutaneous melanomas, six metastatic melanomas, eight melanocytic nevi, 14 breast cancers, seven examples of fibrocystic disease of the breast, 11 lung cancers, and six colon cancers. Virtually all tumors were associated with substantial numbers of T lymphocytes (Leu3a-positive T helper-inducer cells predominating) and macrophages. Primary melanomas contained significantly more T lymphocytes (P less than .002), macrophages (P less than .005), and Langerhans/dendritic cells (P less than .002) than nevi or normal skin and had a higher proportion of T cells than metastatic melanomas (P less than .01). Breast cancers contained more T lymphocytes and macrophages than occur with fibrocystic disease (P less than .0001 and P less than .002, respectively) and more B lymphocytes. Cancers of the lung and colon contained moderate numbers of T lymphocytes and macrophages; however, colon cancers contained a higher proportion of B cells. Leu7-positive NK/K cells were noted in small numbers in all tumors examined.

Natural killer activity of lymphocytic infiltrates in mouse mammary lesions

Tissue infiltrating lymphocytes were isolated from BALB/c line C4 preneoplastic hyperplastic alveolar nodules (HAN) and spontaneous tumours that arose from the HANs. NK activity of the lymphocytic infiltrates was tested in a 4 h chromium release assay using 51Cr labelled YAC cells. In situ lymphocytes of C4 HAN expressed 3-4 fold greater relative lytic activity (Pross et al., 1981) than did normal spleen cells whereas the relative lytic activity of C4 tumour infiltrates was equivalent or less than that of normal spleen cells. Spleen cells of all lesion bearers had reduced cytolytic capacity. YAC cell lysis by spleen cells and HAN infiltrates correlated with increasing E/T ratios. The degree of YAC lysis by C4 tumour infiltrates, however, either decreased, stayed the same, or increased non-exponentially with increasing E/T ratios especially at E/T greater than 50. Indeed, C4 tumour infiltrates from animals pretreated with anti-asialo GM1 (ASGM) could suppress the NK activity of normal spleen cells. The lytic activity of both C4 HAN and tumour infiltrates could be enhanced or depressed by in vivo treatment with poly IC or anti-ASGM, respectively. These results indicate that NK cells are activated or recruited into C4 preneoplastic lesions but their lytic activity wanes and suppressive activity arises with progression to neoplasia.

Specific (EMT6) and non-specific (WEHI-164) cytolytic activity by host cells infiltrating tumour spheroids

The development of a serum-free, low-protein culture medium has allowed the detection of tumour-specific cytolytic cells in EMT6 immunized mice bearing EMT6 multicellular tumour spheroids. Spheroid associated (SAC) and peritoneal (PC) effector cells were specific to EMT6 as the target cell, not killing line 1, P815 or RIF-1. The natural killer (NK) cell sensitive target YAC-1 was also not lysed by SAC or PC, indicating undetectable levels of NK cells present within infiltrated spheroids. In contrast, high levels of cytolytic activity were present in SAC, PC and spleen cells against WEHI-164, a line sensitive to natural cytotoxic (NC) and macrophage mediated killing. The EMT6 specific activity was mediated by Thyl+, Lyt2+ cells. The anti-WEHI-164 effector cell population was Thyl-, Lyt2-. The WEHI-164 killer cells were present in SAC and PC from unimmunized mice while the EMT6 specific effector cells were not. After separation of SAC and PC by size using centrifugal elutriation, anti-EMT6 activity was present only in the lymphocyte fraction while anti-WEHI-164 activity was enriched in the macrophage fraction.

Modification of natural killer activity of lymphocytes infiltrating human lung cancers

The purpose of these studies was to compare local and systemic human lymphokine activated killer (LAK) and natural killer (NK) cytotoxic activity and to determine its modulation by biologic agents. Local immunity may be an important component in limiting local tumor growth. Therefore, as a model for studying immune function in the local compartment, we assessed NK activity of lymphocytes present at the site of human tumors and in peripheral blood (PBL). We extracted tumor infiltrating lymphocytes (TIL) and PBL from patients with pulmonary tumors and compared NK activity and response to the biological modifiers gamma interferon (IFN-gamma), indomethacin (INDO), and interleukin 2 (IL-2). We also studied TIL and PBL LAK activity using the NK-resistant M14 target cells and determined the TIL response to IL-2, plus IFN-gamma. Titration of K562 targets in a 51Cr release assay revealed that untreated TIL have low cytotoxicity (4.32%) compared to untreated PBL (34.3%, P = less than 0.001). This low level of TIL NK activity was not affected by IFN-gamma, INDO, or IL-2 at 1 h. However, at 3 days of culture, IL-2 with or without exogenous IFN-gamma significantly increased TIL NK cytotoxicity (20.5%, P = 0.02 without IFN-gamma and 32.52 lytic units (LU), P = less than 0.02 with IFN-gamma). Untreated TIL and PBL both had low cytotoxicity against M14 targets (1.08 LU and 1.26 LU), respectively. After 3 days culture with IL-2 plus IFN-gamma, both TIL and PBL LAK cytotoxicity were increased (14.34 LU and 40.63 LU). We conclude that local NK and LAK activity is intrinsically low. However, this activity can be modulated by biologic agents, thus giving hope for the development of local anti-tumor effectors capable of in vivo tumor control.

Pharyngeal carcinoma and natural killer cell activity

An evaluation of natural killer cell activity was performed in 42 patients with pharyngeal carcinoma. Compared with age- and sex-matched control subjects, the cancer patients expressed significantly lower cytotoxicity against K562 target cells (68 +/- 8 lytic units versus 99 +/- 8 lytic units, p less than 0.01), with 52 percent of the patients expressing deficient activity (below 1 standard deviation of the mean activity of the control population). The probability of deficient activity was greater in these patients than observed in patients with cancer of other head and neck sites. Although natural killer cell activity was lower in patients who drank alcohol or had nodal metastases, no single clinical factor was predictive of deficient cytotoxic response. Prospective longitudinal evaluation (mean = 12 months) of these pharyngeal cancer patients demonstrated that deficient natural killer cell activity measured before treatment identified a population with a significantly increased risk for the development of distant metastases. Distant metastases developed in 7 of 18 patients (39 percent) with deficient natural killer cell activity. In contrast, none of the 16 patients with normal natural killer cell function had evidence of distant disease at last follow-up (p less than 0.01). Deficient natural killer cell activity exists in patients with pharyngeal cancer and is an independent marker for the subsequent development of distant metastases.

Immunohistochemical study on the distribution and significance of mononuclear cells in human breast carcinoma

Lymphocyte subsets in the tumor nests of breast carcinoma were immunohistochemically investigated and a quantitative analysis was added. The majority of cases showed predominance of T cell and suppressor T cell (T8). A decrease in number of lymphocyte subsets and the helper T (T4)/T8 ratio in the stroma of tumor nests correlated well with the progression of clinical stage and the presence of metastasis. This correlation could not be found in the peripheral region of the tumor nests. Macrophages and NK cells were infrequently observed only in the peripheral region of ductal carcinoma. T cell infiltration was prominent in medullary carcinoma with lymphocyte infiltration (MC), and macrophages, NK cells, and T zone histiocytes were frequently encountered. For the purpose of knowing the activity of T cells, IL-2 receptor (Tac) and transferrin receptor were examined immunohistochemically. The fact that a few activated T cells were found only in the peripheral region of tumor nest suggested the local immune response in ductal carcinoma not to be so active as to reject the tumor cells. Since numerous activated T cells were recognized in the tumor nests of MC, this type of breast carcinoma was thought to have a higher immune reactivity. There was little evidence indicating NK cells to play a role for natural cytotoxicity in breast carcinoma.

Histopathologic high risk factors influencing the prognosis of patients with early breast cancer (T1N0M0)

A retrospective study of 78 women with early breast cancer was undertaken with the aim of detecting histopathologic risk factors that would influence the prognosis of these patients. Histologic tumor type, nuclear grade of tumor, tumor margin, and lymphoid infiltration near the tumor as well as blood vessel invasion and lymphatic tumor emboli were evaluated. The overall 10 year survival rate was 79.2 percent. In correlating the aforementioned criteria against survival rate, it was found that the patients without any of the histopathologic risk factors had a 100 percent rate, whereas those with one risk factor had a 79 percent rate and those with two or more risk factors a 66 percent rate. Nuclear grade and lymphoid infiltration were found to have the highest significance in regard to recurrence and the mortality rate. The findings of this study suggest that in patients classified as having T1N0M0 disease without any of the histopathologic risk factors, operation is the only treatment indicated. Patients with one or more positive risk factors should receive adequate adjuvant therapy in order to increase their survival rate.

Lymphoreticular infiltrates in invasive ductal breast cancer. A histological and immunohistological study

Fifty-two invasive ductal breast cancers were investigated histologically and immunohistologically to assess localization and composition of the lymphoreticular infiltrates. The tumour-infiltrating cells were mainly located in the intervening stroma, whereas tumour foci often exhibited lower numbers of lymphoreticular cells. Macrophages (Mono 1+ and KiM 6+) and helper/inducer cells bearing the T4 surface antigen (Leu-3a+) regularly constituted the majority of the tumour-infiltrating lymphoreticular cells. In more than 80% of cases large numbers of macrophages were found, and many T4 cells occurred in about 60%. Next in frequency were the T lymphocytes (Leu-1+) which were mostly observed in high (46%), or in moderate (39%) numbers. In about 2/3 of the cases moderate numbers of T8 (suppressor/cytotoxic) lymphocytes (Leu-2a+) were detected. B lymphocytes (T0 15+) and natural killer cells (Leu-7+) were generally encountered in very low numbers, while eosinophilic granulocytes were virtually absent from the lymphoreticular infiltrates. Tissue mast cells and plasma cells were present in very low numbers in about one half of the tumours but cases with low, moderate or - rarely - even high numbers of infiltrating cells also occurred. It must be emphasized that an in situ histomorphological analysis of the cellular part of the stromal reaction of invasive ductal breast cancers allows only limited conclusions concerning the functional properties of the tumour-infiltrating lymphoreticular cells. From the present study, macrophages and T4 cells but also T8 lymphocytes might be of significance in immunooncological reactions "against" clinically detectable stages of invasive breast cancer.

The role of transferrin in natural killer cell and IL-2-induced cytotoxic cell function

The growth factor transferrin (Tf) enhanced natural killer (NK) cell cytotoxicity. This enhancement was due to direct effects on NK cell function, and Tf treatment of the K562 target cell had no effect on their sensitivity. NK cells were highly enriched in the low-density large granular lymphocyte population (LGL) by Percoll gradient centrifugation. Despite the direct effect of Tf on NK cells, the number of cells expressing receptors for Tf (TfR) in NK-enriched LGL was the same as the NK-cell-depleted high-density small lymphocyte population (SL). All populations, tested without stimulation, had very few TfR+ cells. Interleukin 2 (IL-2) could induce very high NK-like activity in the LGL but not in SL. Similarly, only LGL could be induced by IL-2 to express TfR. In serum-free cultures, only limited NK-like activity could be developed which was greatly enhanced by supplementing with Tf in the cultures. The importance of Tf in NK-like development was confirmed by modulating the expression of TfR in IL-2 containing cultures with mouse monoclonal antibody OKT9 specific for TfR. OKT9 totally abrogated the induction of cytotoxic activity by IL-2 against K562 and NK-resistant target. OKT9 inhibited the induction of cytotoxicity in both lymphocytes containing active NK cells and in those predepleted of active NK cells, indicating that the development of NK-like activity from both precursor populations requires Tf. The inhibition by OKT9 was only during the induction phase. The same antibody had no effect on the cytotoxicity of fresh NK cells or the mature IL-2-induced NK-like cells. Our data therefore do not support the hypothesis of TfR as the NK recognition structure. Instead, these results indicate that Tf is important for the development of NK and NK-like activities.

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

T lymphocytes were isolated from tumor biopsies in 13 patients with breast carcinomas. Immunohistology with monoclonal antibodies confirmed the presence of mononuclear cell infiltrates composed primarily of T lymphocytes in all tumors studied. While the proportion of T lymphocytes expressing the T4 or the T8 surface marker varied from tumor to tumor as determined by morphometric analysis, T8+ cells were more numerous than T4+ cells in 8/12 breast tumors studied. Relatively few T cells (less than 10% in 11/12 tumors) were in an activated state as judged by the surface expression of HLA-DR antigens or the receptor for interleukin-2 (IL-2). In 1 case 20% of the infiltrating mononuclear cells were expressing the IL-2 receptor. The tumor infiltrating lymphocytes (TIL) recovered from 10 tumors were cloned in a microculture system that permits proliferation of nearly 100% of normal peripheral blood T lymphocytes (PBL-T). In contrast to normal and autologous PBL-T, frequencies of proliferating T lymphocyte precursors (PTL-P) were depressed (less than 0.01) in 7/10 TIL preparations indicating a decreased responsiveness of TIL to phytohemagglutinin at the single-cell level. The frequency of PTL-P was noticeably higher in 2 cases (0.03 and 0.09) and close to normal in 1 case (0.39). A total of 170 clones were expanded in vitro and analyzed for different functional capabilities. Most of these clones expressed the T4+/T8-phenotype (73%) and strikingly 53% of these T4+/T8- clones were cytolytic in a lectin-dependent assay, a functional subset which is uncommon among normal PBL-T. Some clones (10%) lysed allogeneic breast tumor cells (MCF7). Only 15% of the clones displayed natural killer activity. Among the cytolytic clones, 17 of 31 tested were also IL-2 producers irrespective of the T4 or T8 phenotype. Our results show that human mammary carcinomas contain many infiltrating T cells with cytolytic potential. Interestingly, among the proliferating cytolytic T cell clones (56% of the microcultures), many expressed the T4+/T8- phenotype. These findings may indicate that the in situ cytolytic reaction (against unknown antigens) is associated preferentially with class II antigens.

Expression of MHC products and leucocyte differentiation antigens in gynaecological neoplasms: an immunohistological analysis of the tumour cells and infiltrating leucocytes

Monoclonal antibodies directed against monomorphic determinants of Class I and Class II products of the major histocompatibility complex (MHC) and against leucocyte differentiation antigens were used in an indirect immunoperoxidase technique to compare their expression in normal and malignant disease of the ovary, cervix and endometrium. MHC Class I products, strongly expressed on normal ovarian epithelium, were uniformly absent from 7/8 ovarian carcinomas of varying histology. Lack of Class I expression was also a feature of 6/10 cervical carcinomas and of 4/8 endometrial carcinomas, in comparison with their respective normal tissues. Relative to normal tissue epithelium MHC Class II products, could be either lost or gained, the pattern of expression being either uniform or heterogeneous. Leucocytes were sparse in normal ovary but more numerous in cervix and endometrium. In tumours, with few exceptions, they were abundant, though usually confined to the stroma. T cells, largely of cytotoxic/suppressor (OKT8) phenotype, tended to predominate though in some tumours, particularly cervical carcinoma, large numbers of macrophages and to a lesser extent, B cells were sometimes detected. By contrast, leucocytes of natural killer (NK) phenotype were virtually non-existent in any tumour or normal tissue. The ingress of leucocytes into gynaecological neoplasms does not appear to be a random event and may be evoked by an immune response against tumour-associated antigens. However, the relationship between in situ mononuclear cell infiltration and MHC expression on epithelial tumour cells is complex and remains to be elucidated.

Mononuclear cells infiltrating human mammary carcinomas: immunohistochemical analysis with monoclonal antibodies

Breast carcinomas were examined by the immunoperoxidase technique using antisera specific for lymphocyte subsets, monocytes, NK cells and major histocompatibility antigens (HLA-A, -B, -C; Ia-like). Sixty-four per cent of the patients had a moderate or strong mononuclear cell infiltration, 77% of the patients without mononuclear cell infiltration had receptors for estrogens as compared to 51% of the patients with infiltration. The majority of the infiltrating mononuclear cells were T cells; generally the OKT8 cells were predominant. The Leu 3A/OKT8 cell ratio was not related to histological type, tumor size, age of the patient or presence of metastases. Some of the T cells had the Ia antigen and were thus probably activated. The B cells were either absent or less numerous than the T cells. There was no relation between their distribution and the various parameters studied. A few monocytes were heterogeneous according to their markers (OKM I and acid phosphatase). In 6 cases only there was a strong infiltration of mononuclear cells positive for acid phosphatase. The number of the natural killer cells was also low. Only a few mononuclear infiltrating cells had receptors for transferrin. There was a positive correlation between the inflammatory infiltration and the presence of HLA class-I antigens on tumor cells. Some of the antisera specific for lymphocyte subsets also stained the breast carcinoma cells. The great variations in the subsets of mononuclear cells in breast carcinomas may correspond to various systems of defense against neoplasm.

Natural killer cells

It is proposed that this article will encompass a review of primarily the human natural killer cell. The following parameters of the human natural killer (NK) cell will be reviewed: its ontogeny; surface membrane characteristics including monoclonal antibody reactivity, cell lineage, the natural killer sensitive targets, and the proposed mechanism of action of natural killer cells cytotoxicity against these NK sensitive targets; the status of natural killer cell in relationship to clinical disease; the alteration of natural killer cells both in vitro and in vivo; and finally postulate relevance of the natural killer cell in context of the evolution or pathophysiology of human disease. There will be an attempt through this review to encompass the more recent publications that pertain to the various sections.

Distribution of histocompatibility and leucocyte differentiation antigens in normal human colon and in benign and malignant colonic neoplasms

Monoclonal antibodies (McAbs) directed against the framework determinants of Class I and Class II products of the major histocompatibility complex (MHC) and against leucocyte differentiation antigens were used in an indirect immunoperoxidase technique to study their expression in normal, benign (adenomatous polyps) and malignant disease of the colon. Class I products (detected by the McAb 2A1) were strongly expressed on all cell types in normal and benign tissues but some carcinomas exhibited a heterogenous pattern of epithelial cell staining and 4/15 were completely negative. Class II products (detected by TDR31.1) were strongly expressed on cells (mainly B lymphocytes) within the lamina propria. In carcinomas TDR31.1 staining was mainly interstitial, but in 2/15, DR + epithelial cells were also detected. In normal and benign tissues, leucocytes (reactive with 2D1) found predominantly in the lamina propria, comprised T cells mainly of the helper/inducer (OKT4) subset, DR + cells in approx. equivalent proportion and a few OKM1+ cells mostly of macrophage morphology. Occasional intraepithelial lymphocytes were of cytotoxic/suppressor (OKT8) phenotype. In malignant neoplasms, there was wide inter and intra-tumour variation in the proportion of leucocytes which were heterogeneous with respect to cell type and confined mainly to the stroma. T cells were consistently predominant, but B cells and macrophages were also present. Two neoplasms showed unequivocal evidence of a shift (relative to peripheral blood) in favour of the OKT8+ subset, but in the majority of tumours OKT4+; and OKT8+ cells were present in roughly similar proportions. Natural killer cells (monitored with Leu7, HNK1) were virtually undetectable in both normal and malignant tissues. There were no apparent correlations between the extent and type of leucocyte infiltration, tumour differentiation or expression of MHC products. Some implications for the extrapolation of in vitro data on leucocyte function to the in vivo situation are discussed.

Expression of major histocompatibility antigens and leucocyte infiltration in benign and malignant human breast disease

The reactivity of murine monoclonal antibodies (McAbs) directed against the monomorphic determinants of Class I and Class II antigens of the major histocompatibility complex (MHC), and against antigens expressed by discrete populations of leucocytes was studied using the indirect immunoperoxidase technique on serial tissue sections of 16 benign and 17 malignant primary human breast tumours. Class I antigens (detected by the McAb 2A1) were consistently associated with stromal leucocytes, fibroblasts and vascular endothelium, but expression on epithelial cells particularly of malignant provenance, was more variable. Class II antigens (detected by TDR 31.1) were present upon a variety of cell types which also included sporadic expression on malignant and benign epithelia. The distribution of leucocytes grossly monitored with 2D1 (reactive with a common leucocyte antigen) was largely interepithelial and periductal in benign lesions. Leucocytes were generally more numerous in malignant tumours, where they were largely confined to the stroma. The majority (approximately 75%) of leucocytes were T lymphocytes (reactive with UCHT1), some of which appeared to react with TDR 31.1 and were therefore activated. Ratios of helper/inducer (OKT4+) and suppressor/cytotoxic (OKT8+) subsets generally exceeded unity in malignant neoplasms. There was no correlation between the extent and distribution of T cells and the HLA status of the epithelial cells. Leucocytes detected by the monoclonal antibody OKM1 which reacts with monocytes/macrophages, granulocytes and large granular lymphocytes were numerically few and again mainly confined to the stroma. In a limited number of tests, leucocytes detected with HNKl, reactive with a differentiation antigen expressed on some cells which mediate natural and antibody-dependent cellular cytotoxicity in vitro although detectable interepithelially in benign tumours, were virtually absent from malignant tissue. HNK1 also cross-reacted with myoepithelial cells in the ducts of benign lesions.

Native and inducible levels of natural cytotoxicity in lymph nodes draining mammary carcinoma

Lymphocytes isolated from axillary nodes draining breast carcinoma possess variable natural cytotoxic capacity. Augmentation of lymph node cell (LNC) cytotoxicity by interferon (IFN) is also variable, with only some populations displaying potentiated lysis following exposure to either IFN-a or gene-cloned IFN-a2. Where present the IFN-induced augmentation of LNC cytotoxicity was invariably weaker than that observed following similar treatment of autochthonous peripheral blood mononuclear cells (PBMC). Irrespective of their responsiveness to IFN the cytotoxic activity of all LNC preparations examined was significantly increased following pre-incubation with either staphylococcal enterotoxin A (SEA) or factors elaborated by lectin-pulsed allogeneic LNC. THe induction or amplification fo LNC-mediated natural cytotoxicity by lymphokines may provide a local potentiation of natural immune function at the host : tumour interface.

The biology of the human natural killer cell

Natural killer (NK) cells in the human are a population of large granular lymphocytes (LGL) with at least one unique surface antigen not expressed on cells of other lineages. NK-target-cell interaction appears to involve carbohydrate recognition and, following binding, the NK cells are induced to generate O2-, transmethylate membrane phospholipids, and activate phospholipase A2. Some or all of these activities trigger a cascade of events which ultimately leads to the secretion of a substance toxic to the target cell. A variety of genes controls various steps in this cytolytic pathway. There is a good deal of evidence in the mouse, and some in the human, that NK cells play a role in host surveillance against tumor development, resistance to viral infections, and, possibly, hematopoietic regulation.