Isolation and characterization of growth factor(s) from a human B-cell lymphoma

We demonstrate that human neoplastic B cells (Br cells) contain a cytoplasmic protein of molecular mass 60 Kd that exhibits B-cell growth factor (BCGF) activity on growth factor-dependent long-term human B cells as well as on autochthonous tumor cells. This 60-Kd protein is recognized by antibodies against a similar intracellular 60-Kd protein derived from normal human lymphocytes. These results demonstrate that the two proteins share epitope homology. Microculture bioassays indicate that neoplastic and normal 60-Kd proteins are capable of driving neoplastic B cells through S-phase. Western immunoblot analysis indicates that neoplastic B cells secrete 60- as well as 14-Kd protein. Immunoaffinity-purified proteins secreted by Br cells exhibit BCGF activity in anti-IgM or dextran sulfate-preactivated human B cells. In addition, a double-antibody immunofluorescence staining technique was used to demonstrate that Br cells express cell surface receptors for BCGF molecule(s). These studies provide support for the autocrine growth model for neoplastic human B cells and suggest that the autocrine growth factor derived from such tumor cells is similar if not identical to normal BCGF molecules.

In vitro analysis of cell populations involved in Hodgkin's disease lesions and in the characteristic T cell immunodeficiency

Hodgkin's disease (HD) is an aggressive human lymphoproliferative disease that displays a curious pleomorphic histopathologic appearance unlike that of any of the common non-Hodgkin's lymphomas (NHL). Although the bizarre giant cells of the HD lesion, the Reed-Sternberg cells (RSC) and mononuclear variant Hodgkin's cells (HC), have been considered to be malignant cells, little objective evidence supports this conclusion. We have studied the proliferative characteristics of T cell as well as RSC and HC-enriched populations from HD lesions, and found the majority of the proliferative activity in the T cell populations. RSC-enriched populations not only showed little spontaneous proliferation, but also did not respond to a variety of cytokine growth factors in vitro, suggesting that these cell populations are not actively growing cells. Further molecular studies to identify possible monoclonal T or B cell populations in HD lesions, using a TCR beta chain probe and IgH probes respectively on Southern blot analysis, revealed no evidence of monoclonal lymphoid cell populations. Additional studies on the characteristic T cell immunodeficiency in HD were also undertaken. Our previous studies had associated a decrement in IL-2 production with this defect. Our studies now show that an intrinsic T cell abnormality exists when HD patients' T cells are stimulated with agonistic MAb that can optimally activate and stimulate IL-2 production in normal control T cells.

In vitro studies on leukemia cells and T lymphocytes in hairy cell leukemia

Hairy cell leukemia cell lines were established from eight untreated patients using purified B cell growth factor (BCGF) in vitro. These cell lines maintained their original cell surface immunophenotype for about 1 month, after which they began to lose one or more of their characteristic surface antigens. The cell lines also maintained typical hairy cell leukemia morphology for 2-3 months in vitro but later showed an increasing number of multinucleate giant cells that maintained a B cell surface phenotype. The cell lines became independent of exogenously provided BCGF after at least 1 month in vitro and secreted BCGF activity into culture supernatants in most cases. Some cell lines also acquired Epstein-Barr virus nuclear antigen positivity after variable period. Two hairy cell leukemia patients also showed hyperactive T cell responses in vitro and exhibited spontaneous T cell proliferation in culture without exogenously supplied interleukin-2. These T cell lines had the T helper phenotype and secreted significant amounts of T cell-associated lymphokines with BCGF and interleukin-2 activity into culture supernatants.

Double immunoenzymatic labeling of lymphomatous tissues for both immunologic phenotype and a malignancy-associated nucleolar antigen

Defining cell lineage in the non-Hodgkin's lymphomas (NHL) is challenging for the immunopathologist. Cell surface marker techniques have made a major contribution to the understanding of the biology and classification of lymphoproliferative disorders by permitting the determination of the lymphoid (B- or T-cell) or monocytic lineage of the tumors. Because lymphoma cells often simulate the morphologic features and cell surface phenotype of their normal lymphocytic counterparts, it is difficult to discriminate normal from neoplastic lymphocytes. The authors have used representative monoclonal antibodies (MAb) to cell surface antigens to assess tumor cell surface antigens associated with various lymphoreticular cell lineages. Heteroantisera to the human malignancy-associated nucleolar antigen (HMNA) was utilized as a marker for neoplastic lymphoid cells as previously described. The use of double immunoenzymatic staining with both peroxidase and alkaline phosphatase allow us simultaneously to determine lymphoid lineage and malignancy on human lymphoma cells. In 101 cases of various cell types of NHL, the anti-HMNA antiserum reacted with nucleoli in the morphologically neoplastic lymphoma cells, but not with normal-appearing lymphoid and other cell types present in the lesions. Control specimens from normal and hyperplastic lymphoid tissue also failed to react with anti-HMNA antibodies.

Production of B cell growth factor(s) by neoplastic B cells from hairy cell leukemia patients

Recent studies have shown that normal human T cells contain a high-molecular-weight (mol wt) protein exhibiting B cell growth factor (BCGF) activity. Other studies have shown that virally transformed human B cells also secrete a high-mol-wt BCGF-like molecule in vitro. We have studied neoplastic B cells from patients with untreated hairy cell leukemia (HCL) to ascertain whether such cytoplasmic BCGF activity is present in the tumor cells. Studies on HCL cells from four patients indicated that BCGF-like activity was in fact present in the cytosolic extracts when tested on autochthonous HCL cells as well as on normal BCGF-dependent human B cell lines. Chromatographic analysis indicated that the BCGF activity from HCL cells was similar in mol wt as well as function to the normal T cell-derived cytosolic BCGF activity. These studies suggest that HCL cells contain and, in some cases, secrete a high-mol-wt growth factor that can be autostimulatory and appears to resemble a similar growth factor molecule found in normal human T cells.

Growth factor-mediated tumor cell proliferation in hairy cell leukemia

Leukemic B cells from seven patients with hairy cell leukemia (HCL), six of which contained the Tac antigen, were assayed in vitro for growth factor-mediated cell proliferation. The HCL cells showed typical phenotypic profiles by monoclonal antibody analysis. The tumor cells, which do not grow spontaneously in vitro, were found to proliferate in all but one case in response to partially purified B cell growth factor (BCGF) without anti-mu or Sac activation. Recombinant interleukin 2 however produced only a marginal response and could not support leukemic cell growth in vitro. BCGF, however, did stimulate in vitro cell growth and supported the establishment of continuous (greater than 60 d in vitro) in four of the seven HCL cases.

Growth factor-mediated proliferation in B cell non-Hodgkin's lymphomas

The non-Hodgkin's lymphomas (NHLs) are a heterogeneous group of human lymphoid tumors, primarily of B cell lineage, which appear to represent arrested stages in B lymphocyte differentiation. Control of cell proliferation is a fundamentally important but poorly understood area of study in these tumors. We have studied a representative group of B cell NHLs to assess their potential for growth factor-mediated proliferation in vitro. Our results show that purified monoclonal NHL B cells of the small cell (well-differentiated lymphocytic lymphoma, nodular poorly differentiated lymphocytic lymphoma, etc) type, that were positive for the human malignancy-associated nucleolar antigen could be stimulated by human B cell growth factor (BCGF) to proliferate in vitro. Other B cell activators such as insoluble anti-Ig and the mitogen protein A also could stimulate thymidine incorporation in the lymphoma cell populations. In vitro lymphoma cell growth could be maintained in the presence of the growth factor for up to five weeks. The large B cell type NHL, however, appeared to be refractory to in vitro stimulation by BCGF as well as other stimulators of normal B cells. These studies suggest that human B cell lymphoid tumors are not only phenotypically similar to their normal B lymphocyte counterparts, but are also sensitive in some cases, to the same types of immunoregulatory molecules that control normal lymphoid cell growth.

Association of an interleukin abnormality with the T cell defect in Hodgkin's disease

The cellular immune defect in untreated Hodgkin's disease (HD) has long been recognized. This defect appears to be responsible for at least some of the morbidity and ultimately the mortality associated with the disease. In recent years, many studies have shown that the T cell component of the immune response is the apparent site where the defect in HD exists and where the immunoregulatory abnormalities that may account for the deficit are observed. The discovery of the lymphokines and monokines, comprising the human interleukin system, has elucidated some aspects of the regulatory control of the functional pathways involved in T lymphocyte activation and proliferation. The interleukin system can therefore provide the framework to dissect immunodeficiency states, such as that seen in HD. The present study indicates that HD patients' interleukin 1 (IL1) response appears to be normal, as is their T cell proliferative response to exogenous IL2. Interleukin 2 production by HD patients' peripheral blood mononuclear cells, however, is decreased when compared with age/sex-matched controls. The inability to generate IL2 after appropriate stimulation may reflect either a primary cellular defect or a regulatory defect, such as excessive immunosuppression, giving rise to the characteristic T cell hyporesponsiveness seen in HD.

Identification of human lymphoma cells by antisera to malignancy-associated nucleolar antigens

The non-Hodgkin's lymphomas (NHL) are a diverse group of human lymphoid neoplasms that have long presented pathologists with formidable diagnostic challenges. These tumors of the immune system are thought to represent neoplastic transformations of most of the recognized stages in T and B lymphocyte ontogeny. Lymphoma cells, however, often simulate their normal lymphocytic counterparts both morphologically and cell surface phenotypically, creating difficulties in discriminating normal from neoplastic lymphocytes. We have used heteroantisera to the human malignancy-associated nucleolar antigen (HMNA) to prospectively evaluate its efficacy in identifying the morphologically neoplastic cells in NHL lesions. In 65 cases of T and B cell histopathologic types of NHL, the antisera reacted with nucleoli in the morphologically and cytogenetically neoplastic lymphoma cells, but not with normal-appearing lymphoid and other cell types present in the lesions. Control specimens from normal and hyperplastic lymphoid tissue also failed to react with anti-HMNA antibodies. Normal activated lymphoid cells in vitro and growth-factor-dependent normal lymphoid cell lines also failed to express the nucleolar antigen(s). These data suggest that the HMNA is a valuable tumor cell marker for neoplastic human lymphoid cell populations and can be used with other types of cell markers for a better definition of the neoplastic cells in NHL.

Double primary malignancies: osteosarcoma and medulloblastoma

We report the case of an 8 1/2-year-old boy who, after successful treatment for osteosarcoma, had a fatal medulloblastoma. We discuss the possible causes for such an association.

Suppression of lymphocyte responses by monocytes with untreated and treated multiple myeloma

Studies were performed on 15 untreated and 14 treated patients with multiple myeloma. The monocyte content was normal in blood but elevated in mononuclear leukocytes (MNL) from treated but not untreated patients (p less than 0.001). This correlated with the severity of lymphopenia in blood (p less than 0.01). Three patterns of immunoglobulin(Ig) synthesis emerged. (1) Most untreated patients showed normal polyclonal responses to pokeweek mitogen. (2) Of 12 treated patients, the 8 whose MNL included greater than 30% monocytes had subnormal Ig responses to pokeweek mitogen. Ig synthesis increased when adherent cells that suppressed Ig synthesis were depleted. Suppression in vitro bore no relationship to polyclonal immunoglobulin levels in serum. (3) Three patients had early blood invasion by plasmacytoid cells. Their MNL spontaneously released large amounts of the Ig class of their serum gammopathies. Proliferative responses to phytohemagglutinin by MNL from all patients were reduced, in part due to monocytoid cell suppression and in part to intrinsic T-cell hyporesponsiveness. B- and T-cell responses in vitro are sometimes suppressed with myeloma. This is related to elevated monocyte percentages in MNL preparations. This excess of monocytes is a function of lymphopenia secondary to therapy, rather than the primary malignant process itself. No evidence was found that suppression by monocytes is qualitatively altered by myeloma or its treatment.

Growth factors in Hodgkin's disease

Tumor nodules from spleens removed at staging laparotomy for nodular sclerosing Hodgkin's disease were grown as fragment cultures in vitro. These cultures could be maintained in vitro for up to 2 months and consisted of 90% large, adherent multinuclear and mononuclear cells. Immunologic markers and enzyme histochemistry suggested that the cultured cells belonged to the monocyte/macrophage lineage. Supernatants from these cell cultures were then assayed for the monokine Interleukin I and for fibroblast stimulatory factors, which were both present. These results are discussed in considering Hodgkin's disease as a neoplasm of the monocyte/macrophage lineage, capable of producing functionally active mediators that may account for the histopathologic appearance observed.

The characterization of trypan blue-induced tumors in Wistar rats

Trypan blue is an azo dye widely used for testing cell viability. The dye has been identified as a mutagen and a carcinogen. In some strains of rats, particular Wistar rats, chronic exposure induces a reticuloendothelial neoplasm, predominantly in the liver. These tumors were studied with the use of immunologic cell membrane markers, electron microscopy, and histochemistry to characterize tumor cell type. The authors have studied this tumor in two inbred lines of Wistar rats to compare the efficacy of two previously described dye regimens on tumor incidence and to ascertain whether a short, intense exposure was as effective as chronic protracted exposure. No significant difference in tumor incidence was observed between the two regimens. These studies suggest that the tumor is composed of a macrophage-like cell that retains some characteristics of normal macrophages and that is a reproducible model for carcinogen-induced lymphoreticular human lymphomas.

Human T lymphocyte/monocyte interaction in response to lectin: kinetics of entry into the S-phase

PHA-mediated mitogenesis of human peripheral blood T lymphocytes was studied by using highly purified cell populations. The kinetics of human, mature T cell [3H]-Tdr incorporation were examined with respect to those elements necessary and sufficient for the progression of the activated T cell into the S-phase of the cell cycle. These experiments indicated that although a lectin may independently initiate morphologic T cell blastogenesis, this event is not associated with significant progression through the G1 phase of the cell cycle. This blastogenic response is associated with the subsequent T cell receptivity to monocyte-initiated cell cycle progression, and the effect of monocytes can be substituted by partially purified Interleukin 1 (IL-1). Progression of a lectin exposed T cell into the S-phase of the cell cycle could also be achieved by exposing the activated T cell to partially purified Interleukin 2 (IL-2). Given the prior demonstrations that IL-1 functions to induce the T cell-dependent production of the IL-2, it appears that IL-2 is the requisite signal necessary for the activated human lymphocyte to actually progress through the prereplicative phase of the cycle into the S-phase.

Human T lymphocyte/monocyte interaction in response to lectin: kinetics of entry into the S-phase

PHA-mediated mitogenesis of human peripheral blood T lymphocytes was studied by using highly purified cell populations. The kinetics of human, mature T cell [3H]-Tdr incorporation were examined with respect to those elements necessary and sufficient for the progression of the activated T cell into the S-phase of the cell cycle. These experiments indicated that although a lectin may independently initiate morphologic T cell blastogenesis, this event is not associated with significant progression through the G1 phase of the cell cycle. This blastogenic response is associated with the subsequent T cell receptivity to monocyte-initiated cell cycle progression, and the effect of monocytes can be substituted by partially purified Interleukin 1 (IL-1). Progression of a lectin exposed T cell into the S-phase of the cell cycle could also be achieved by exposing the activated T cell to partially purified Interleukin 2 (IL-2). Given the prior demonstrations that IL-1 functions to induce the T cell-dependent production of the IL-2, it appears that IL-2 is the requisite signal necessary for the activated human lymphocyte to actually progress through the prereplicative phase of the cycle into the S-phase.

SJL tumor: a neoplasm involving macrophages

Tumor-bearing lymph nodes from SJL mice were characterized by histologic, ultrastructural, and immunologic methods. These approaches consistently revealed a predominance of macrophage-like cells in the primary neoplasm. When the tumor-bearing lymph nodes were placed in cell culture, colonies of adherent cells grew slowly to confluence and demonstrated morphologic and functional properties of macrophages. The tumor cells were also grown in soft agar where clusters and colonies of large, often binucleate, cells predominated. These cells were uniformly nonspecific esterase-positive, again, suggesting a macrophage origin. In addition, supernatants derived from SJL tumor cells were shown to have mitogen-augmenting activity as tested on murine thymocytes. These findings are discussed in the context of the SJL tumor as a proliferative condition primarily involving macrophages, which may be useful as a model of human diseases such as Hodgkin's disease.

Effect of interleukin 1 on human thymocytes and purified human T cells

Human Interleukin 1 (IL-1) purified by molecular weight fractionation, isoelectric focusing, and gel electrophoresis has been tested on human thymocytes and highly purified human T cells. IL-1 prepared in this manner could not support the long-term growth of T cells yet would augment lectin-stimulated mitogenesis. The IL-1 preparations were shown to possess the lectin-augmenting activity at dilutions containing less than 1 ng of the measurable protein. These data are in agreement with the model that IL-1 stimulates production of IL-2 from lectin-stimulated lymphocytes.

Siderosis of lymph nodes patients with Hodgkin's disease

Lymph nodes removed from 28 untreated patients with Hodgkin's disease all contained markedly increased amounts of hemosiderine, whether or not they were histologically involved in the disease. This finding was particularly striking in patients with the nodular sclerosis type of disease. Abnormal deposits of iron were also noted frequently in lymph nodes containing metastatic carcinoma, lymphoma of non-Hodgkin's type, and reactive hyperplasia, but in each case, with the exception of metastatic squamous cell carcinoma, the amount was significantly less than seen in Hodgkin's disease. The findings suggest that in patients with Hodgkin's disease and perhaps in those with other disorders in which abnormal tissue retention of iron underlies sideropenic anemia, lymph nodes are an important site of iron retention.