Differentiation and maturation of human B lymphocytes: a review

Growth of B cell colonies independent of T cells: a new perspective

Growth of human peripheral blood B cells in a B cell colony assay system is a useful technique to study the function of B cell biology. In the initial reports, T and B cells were admixed in the culture system, prior to which the T cells were treated with mitomycin or irradiation to prevent their proliferation. There were reports that optimal growth of B cell colonies required T cells to be in contact with the B cells. However, we were able to grow B cell colonies physically separated from T cells which were placed on a filter. We speculated then that T cells contacted B cells via pseudopods through the pores of the filter. We now report the growth of B cell colonies independent of T cells and conclude that B cell colony growth depends upon a critical number of B cells plated rather than on T cell help.

Abnormal response to IL-5 in B-cell chronic lymphocytic leukemia

In B-cell chronic lymphocytic leukemia, neoplastic B-lymphocytes are arrested in development. Since interleukins are essential for B-cell differentiation, we examined whether B-CLL cells were capable of responding normally to interleukins. Purified B-lymphocytes from B-CLL patients and controls were compared for their ability to proliferate and differentiate after stimulation with MCAT or SAC plus rhIL-2 or rhIL-5. When rhIL-5 was added to MCAT-stimulated cells, 8 of 10 controls showed a substantial increase in IgM production, compared with only 1 of 10 B-CLL patients. Lack of IL-5 responsiveness could provide insight into the arrested B-lymphocyte development of some B-CLL patients.

Interleukins 1, 4 and 6 induce the colony formation of human bone marrow B lineage cells

An agar-based, B cell colony assay (McGinnes, K. et al., Blood 1990. 76:896) has been used to study the influence of known cytokines on the growth of B lineage colonies initiated by cells from normal, human bone marrow samples. We demonstrate that a combination of interleukin (IL) 1, IL4 and IL6 act directly to promote the generation of plaque-forming colonies. IL6 was shown to act at a late stage of colony formation, which is consistent with its role in the induction of immunoglobulin secretion from mature B cells. In contrast, IL 1 and IL 4 were required at earlier stages in the formation of colonies containing cells which secrete immunoglobulin.

Different lymphocyte compartments respond differently to mitogenic stimulation after thermal injury

Because of the association between the development of an immunocompromised state and an increased risk of infection, increasing attention has been focused on describing and characterizing the immune consequences of thermal injury. Results of human studies are largely based on the in vitro responsiveness of peripheral blood leukocytes, while splenocytes are generally used in the animal studies. Because the response of lymphocytes from different lymphocyte compartments may vary, we compared the responses of murine peripheral blood, splenic, Peyer's patch, and mesenteric lymph node lymphocytes to a battery of mitogens after thermal injury. Burn-induced immunosuppression was maximal in the splenic lymphocyte compartment, where the responses to all three test mitogens were depressed throughout the 28-day postburn study period. Although the PHA-induced mitogen response of lymphocytes from the other three lymphoid compartments remained suppressed throughout the study period, the response to the mitogens Con-A and PWM generally returned to normal or supranormal levels by the seventh postburn day, Therefore it appears that the effect of a thermal injury on lymphocyte function varies according to the lymphocyte compartment examined and the mitogen tested. These results raise the question of whether animal studies using splenic lymphocytes can be correlated with human studies performed on circulating blood lymphocytes.

The tissue distribution of Ia- and IgM-positive cells in adult and newborn miniature pigs

Distribution of Ia- and IgM-positive cells was compared in tissues of adult and newborn miniature pigs, using indirect immunoperoxidase and immunofluorescent techniques with monoclonal antibodies. The different distribution patterns were found mainly in adult jejunum and kidney. Both IgM- and Ia-staining were ascertained in the lamina propria between the Lieberkühn crypts and in the lymphoid follicles of the jejunum. Moreover, IgM-positive cells were demonstrated in the crypts while Ia-reaction was seen in the lamina propria of the villi. In the kidney, IgM-staining was limited to the glomeruli. On the contrary, a distinct Ia-reaction was found mainly in intertubular structures. Small differences in IgM- and Ia-positive cell distribution were also noted in the mesenteric lymph nodes and in the spleen. Developmental changes of the adult distribution patterns (chiefly that of IgM-positive cells) were found in all tissues studied at 2 days of age.

Correlation between histology and immunophenotype in a series of 322 cases of non-Hodgkin's lymphoma

The non-Hodgkin's lymphomas (NHL) are a heterogeneous group of lymphoid neoplasms displaying a wide variation in cell morphology, histological patterns, immunological phenotype and prognosis. In this paper we compare the results of phenotypic investigation of 322 tissue biopsies with the histology based on the Kiel classification. Immunological analysis revealed that 81 per cent of these tumours were of B cell origin, 12 per cent of T cell origin and the remaining 7 per cent could not be characterized as representing either cell lineage. This last group included a number of cases which had received a histological diagnosis of true histiocytic lymphoma. The original morphological diagnosis, based on routine haematoxylin and eosion sections correlated with the immunologically determined phenotype in 86 and 93 per cent of the T- and B-cell cases respectively. The B cell tumours were phenotypically heterogenous with respect to immunoglobulin (Ig) heavy chain and B lymphocyte subset marker expression. IgG was most often found associated with NHL of cb/cc histology and a small subgroup of lymphocytic NHL. IgA expression was uncommon and occurred in combination with IgD and G in three cases and alone in two cases of NHL. The most common immunoglobulin isotype expressed was IgM this isotype occurred with IgD most often in lymphocytic and centrocytic NHL and less often in tumours of cb/cc histology. Whilst greater than 90 per cent of the lymphocytic NHLs expressed the CD5 antigen, between 20 and 75 per cent of B-cell tumours of other histologies also expressed this epitope. The CD10 antigen and the epitope recognized by the monoclonal reagent FMC7 were widely distributed on tumour cells from all histologies. TdT expression commonly regarded as a marker for immature cells was found in one case of follicle centre cell lymphoma. All cases of T cell NHL displayed marked heterogeneity for both pan T and T subset antigens which is significant in terms of the routine diagnosis of T NHL and with regard to the rational classification of node based T NHL. Unlike resting peripheral blood T cells, MHC class II, OKT 10 and CD25 epitopes were expressed reflecting activation of tumour populations.(ABSTRACT TRUNCATED AT 400 WORDS)

Bilateral testicular and adrenal malignant lymphoma of pre B-cell type

A rare case of pre B-lymphoblastic lymphoma of the testes and adrenal glands is presented. No lymph node, central nervous system or bone marrow involvement was demonstrated at diagnosis. The primary presentation was of acute unilateral pain and swelling, mimicking simple orchitis. The diagnosis was made using aspiration cytology and the lymphoma characterized using immunohistochemical, electron microscopic and karyotype analysis techniques. Pre B-cell markers were clearly demonstrated by all criteria used. Monoclonal antibodies (FMC 29 and FMC 31) were used to define the early B-cell nature of the lymphoma. Confirmation using karyotype analysis in addition to immunoglobulin and T-cell beta-receptor gene rearrangement was obtained. Intrathecal chemotherapy was used prophylactically. Combination chemotherapy produced regression of the primary lymphomatous lesions, but subsequent bone marrow spread led to death.

Immunocytochemical analysis of immunoglobulin-containing cells in CSF and blood in inflammatory disorders of the central nervous system

Cells containing immunoglobulins G, A, and M were evaluated in paired cerebrospinal fluid (CSF) and peripheral blood (PB) samples. These were obtained from 12 patients with bacterial meningitis, 14 patients with viral meningitis, 6 cases of lymphocytic meningoradiculitis (LMR), 10 cases of multiple sclerosis (MS), 6 cases of herpes zoster ganglionitis and 27 patients with non-infectious disorders of the CNS. PB cells from 20 healthy donors served as controls. Using alkaline phosphatase (AP)-conjugated antibodies to human immunoglobulin (Ig) G, A, and M in a carrageenan solution it was possible to demonstrate repeatedly intracytoplasmic Igs over more than 1 year without any detectable loss of specificity and staining intensity. Immunoglobulin-containing cells (ICC) could be detected in the CSF of 96% of patients with inflammatory diseases of the central nervous system (CNS) or with MS but not in the control cases.

A simple guide to the terminology and application of leucocyte monoclonal antibodies

This review aims to provide a simple guide and quick reference to the terminology and diagnostic applications of leucocyte monoclonal antibodies. The differentiation cluster terminology, where applicable, is used throughout.

Theoretical and practical aspects of B-cell activation: murine and human systems

We have reviewed observations which were made during studies of murine and human B-cell responses in vitro. One currently faces difficulties in drawing any clear schema as to which external signals elicit which responses (activation, proliferation, differentiation) in B cells. However, the most potent antigen-dependent or polyclonal B-cell responses in vitro occur when, in addition to various cytokines, accessory cells, serum etc., the cultures contain either a) intact T-helper cells which enter into cell-to-cell contact with B cells, or b) some B-cell "mitogen" (T-independent antigen). Murine B cells activated with LPS and anti-Ig antibodies represent a model for the study of IL2 receptor expression and function. LPS does not act on human B cells. Certain mutant EL-4 thymoma cells are potent activators of murine and human B cells via a direct cell-to-cell interaction. The majority of human B cells can be induced to proliferate and generate a few hundred antibody-secreting cells each in the presence of such thymoma cells and a mixture of cytokines. From a practical point of view, this observation should be useful in a variety of investigations such as the analysis of the human B-cell specificity repertoire.

Mechanisms of immunomodulation by drugs

Immunomodulators are those extrinsic or intrinsic substances which regulate or alter the scope, type, duration or competency of the immune response. This paper presents an overview of the mechanisms of immunomodulation, and discusses selected chemical and biologic substances which are capable of modifying the immune or biologic response of the organism. The immunopharmacology, including in vivo and in vitro assays, of a novel acridine immunomodulator is discussed. This low molecular weight compound is an immunomodulator and anti-cancer adjuvant, which has been shown to induce high levels of circulating interferon in mice, protect mice against lethal viral infection, stimulate macrophage and NK cell cytotoxicity for tumor cells, partially restore humoral and cellular immune responses in tumor bearing immunosuppressed mice, and augment the cytotoxic T-lymphocyte response to syngeneic tumor cells. Tissue changes, consisting of presence of drug bound to lysosomal membranes, perivascular infiltrates in mouse liver, glomerular hyalinization in mouse kidney, and focal myocardial changes in mice are described. The compound persists intracellularly for extended periods of time in cells with high lysosomal activity. The tissue changes are interpreted to be a result of overloading of cellular mechanisms for elimination from the cells involved.

A cytological analysis of FMC-7 positive leukaemias

The subdivision of the B lymphoid leukaemias by conventional techniques is subjective and poorly reproducible, with a range of cytological diagnoses available for cases which are not typical examples of chronic lymphatic leukaemia or acute lymphoblastic leukaemia. The monoclonal antibody FMC-7 recognizes a determinant on a subpopulation of B lymphoid cell and stains follicular B cells. Routiune FACS analysis of chronic lymphoid leukaemias with a panel of monoclonal antibodies identified a subset of lymphoproliferative disorders (20 of 88) which were FMC-7 positive. a careful 'blind' cytological assessment of this subset gave some support for the suggestion that they were examples of lymphoproliferative disease of follicular origin. Eight cases, however, were considered cytologically typical of CLL. The wider application of this antibody, particularly in sequential studies over a longer time scale may improve objectivity in the classification of this group of diseases.