Presence Of T-lymphocytes Research Articles

Ovarian leukocytes: Association with follicular persistence and cyst formation in dairy cows

One of the initial causes of cystic ovarian disease (COD) is a failure in the normal ovulation mechanism. This study aimed to characterize the populations of immune cells (T-lymphocytes, B-lymphocytes, monocytes-macrophages and granulocytes) present in the ovary of cows with COD and induced follicular persistence, and evaluate their relation with follicular persistence and cyst formation. The follicular persistence model was developed using a progesterone (P4) slow-release intravaginal device, to obtain subluteal concentrations of P4. Results evidenced that T-lymphocytes, B-lymphocytes and monocytes-macrophages in the cortex, medulla, and theca externa and interna of dominant follicles were higher in the control group than in the COD and all persistence groups. Granulocytes in the medulla and theca externa of dominant follicles were lower in the control group than in the COD group, and those in the cortex and medulla were lower in the control group than in the persistence groups. The presence of T-lymphocytes, B-lymphocytes and granulocytes in the follicular fluid was abundant, especially that of granulocytes, without differences between control and COD cows. These results suggest that the immune system potentially plays a role in the local mechanisms of COD pathogenesis in dairy cows. In spontaneous COD and in our follicular persistence model, the distribution of the cells studied was different from that in the control group. However, to our knowledge, this is the first report describing the presence of immune cells in bovine follicular fluid samples and the expression of steroid hormone receptors in infiltrating immune cells in the bovine ovary.

SUBSTANTIATION OF DIAGNOSIS AND TREATMENT OF CHRONIC RECURRENT APHTHOUS STOMATITIS IN CROHN’S DISEASE

The aim: To substantiate the diagnosis and treatment of chronic recurrent aphthous stomatitis in Crohn's disease. Materials and methods: The analysis of diagnostic and treatment of 52 patients with chronic recurrent aphthous stomatitis in Crohn's disease (main group), mean age 31.8 + 2.3 was performed. The comparison group consisted of 50 patients with chronic recurrent aphthous stomatitis not associated with Crohn's disease (mean age 34.7 + 1.8). Patients in both groups were studied for clinical manifestations, morphological and immunohistochemical studies the aphthae on the oral mucosa were performed. Results: An objective evaluation of the oral mucosa showed that the aphthae on the oral mucosa in patients of both groups did not differ visually. In the morphological study, the patients in the main group had granulomatous inflammation of the oral mucosa, characteristic of Crohn's disease, while the patients in the comparison group had fibrinous inflammation. Immunohistochemical study of the cell infiltrate phenotype in the area of the lesion revealed that the patients in the main group there prevailed CD68+macrophages, the appearance of both intraepithelial and cell infiltrates of T-lymphocyte suppressors, which is characteristic of Crohn's disease. Conclusions: Diagnosis of chronic recurrent aphthous stomatitis in Crohn's disease is based on biopsy of the aphthae on the oral mucosa and their morphological examination, the results of which confirm the presence of granulomatous inflammation, with a large number of macrophages, the presence of T-lymphocytes, characteristic of Crohn's disease, while recurrent aphthous stomatitis of another genesis morphologically detect fibrinous inflammation. The choice of therapeutic tactics for chronic recurrent aphthous stomatitis depends on the results of the morphological study. When granulomatous inflammation is detected in patients with chronic recurrent aphthous stomatitis, which is characteristic of Crohn's disease, in addition to topical treatment of the oral mucosa, specific therapy with mesalazine drugs is prescribed.

FRI0036 Increased macrophage infiltration and trap activity characterize subchondral bone sclerosis in knee osteoarthritis

BackgroundRecent investigations have provided substantial evidence that distinct molecular and morphological changes in subchondral bone tissue, most notably sclerosis, play an active and important role in the pathogenesis of OA....

EBV lytic infection enhances transformation of B‐lymphocytes infected with EBV in the presence of T‐lymphocytes

Epstein-Barr virus (EBV) establishes lifelong latency in B-lymphocytes following infection. Although in immune-competent individuals EBV remains in a quiescent state, in immunodeficient individuals, such as those with AIDS or transplant recipients, B-lymphocytes infected with EBV proliferate to give rise to lymphoproliferative diseases. Similarly, in vitro, EBV transforms human B-lymphocytes into indefinitely growing lymphoblastoid cell lines (LCLs) in the absence of cytotoxic T-lymphocytes. Although LCLs harbor the entire EBV genome as an episome, in most cells the virus remains in a latent state expressing a fraction of EBV genes, and lytic infection occurs spontaneously but only in a small percentage of cells. Here, we report that lytic infection contributes to EBV-induced lymphoproliferation by a paracrine mechanism. An EBV immediate-early protein, BZLF1, induces IL-13, thus facilitating the proliferation of EBV-transformed B-lymphocytes in the presence of T-lymphocytes. These data suggest that lytic gene products could contribute to virus-induced oncogenesis by a paracrine mechanism.

Occurrence of T-Lymphocytes with Aberrant Immunophenotypes Suggestive of Mature T-Cell Neoplasms In Patients with Hairy Cell Leukemia

AbstractAbstract 4165Mature T-Cell Neoplasms (MTN) comprise a heterogeneous group of diseases with largely varying clinical courses ranging from indolent cases which are asymptomatic for years to aggressive cases requiring immediate therapy. The incidence of MTN is increasing with age, however, particularly due to the large group of cases with very indolent clinical course MTN are considered underdiagnosed to a significant portion. Published data indicates that T-lymphocytes with aberrant immunophenotype, i.e. double-positive cell expressing both CD4 and CD8, are present in healthy subjects, however, their frequency in general amounts to clearly less than one percent of total leukocytes. With increasing age, these T-lymphocytes with aberrant immunophenotype are detected in more subjects and at higher frequencies suggesting a higher incidence of mature T-cell neoplasms or at least of pre-malignant conditions in these cases. The diagnosis of hairy cell leukemia has not yet been linked to a higher frequency of these T-lymphocytes with aberrant immunophenotype or of MTN. Following the identification of various cases with both a diagnosis of hairy cell leukemia and the presence of T-lymphocytes with aberrant immunophenotype in our laboratory we hypothesized that both of these conditions co-occur at a higher rate than would be expected by chance. We therefore retrospectively evaluated multiparameter immunophenotyping results of 338 patients diagnosed with hairy cell leukemia (newly diagnosed or during follow-up) between August 2005 and July 2010 for the presence of an increased percentage (more than 1%) of T-lymphocytes with an aberrant immunophenotype. We identified 31 such patients, i.e. 9.2% of all patients with hairy cell leukemia. 17 were identified at initial diagnosis and 14 during follow-up after therapy for hairy cell leukemia. The patients' ages ranged from 43.4 to 89.3 years (median, 62.1 years), 21 were male. The aberrant immunophenotype comprised the coexpression of CD3, CD4, and CD8 in all cases and in addition of CD56 in 25/31 (80.6%) cases. The median values and ranges for blood cell counts amounted to: WBC, 2.6 ×10e9/l, 1.0–24.6 ×10e9/l; hemoglobin, 12.7 g/dl, 7.3–16.5 g/dl; thrombocytes, 116 ×10e9/l, 24–258 ×10e9/l. The percentage of T-lymphocytes with an aberrant immunophenotype (compared to all leukocytes) ranged from 1% to 22% (median, 4%); the respective concentrations ranged from 0.013 ×10e9/l to 0.984 ×10e9/l (median, 0.122 ×10e9/l). The concentrations of T-lymphocytes with an aberrant immunophenotype tended to be higher in cases at follow-up as compared to those at initial diagnosis, although this difference was not significant (mean±SD, 0.266±0.275 ×10e9/l vs. 0.144±0.119 ×10e9/l). In four of the 31 patients with T-lymphocytes with an aberrant immunophenotype molecular genetic analysis of T-cell receptor (TCR) rearrangement was performed. In 3/4 patients both TCR beta and gamma were found rearranged and in one of these also TCR delta was rearranged, however, in 1/4 patient no TCR rearrangement was present. This data indicates that T-lymphocytes with aberrant immunophenotypes are present in patients with hairy cell leukemia much more often and at higher concentrations than in the general population. This data therefore suggests that the incidence of mature T-cell neoplasms may be higher in hairy cell leukemia patients. Clinical symptoms and findings like cytopenia and splenomegaly therefore may not be attributable to hairy cell leukemia alone which may have significant therapeutic implications. It is suggested to monitor for T-lymphocytes with aberrant immunophenotypes in patients with hairy cell leukemia and to perform analysis for TCR rearrangements in positive cases. Disclosures:Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Schnittger:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

The effect of a4β7 blockade on T-lymphocyte trafficking to intestinal compartments in the normal and inflamed intestine

Blockade of the integrin α4β7 has demonstrated promise as an organ specific therapy for the treatment of inflammatory bowel disease (IBD). It is believed that the therapeutic effect of α4β7 blockade is mediated by inhibiting T-cell trafficking into the intestine, however the specific T-lymphocyte compartment affected by α4β7 blockade and the effects of α4β7 blockade on normal T-lymphocyte trafficking and during acute injury are not well understood. In this study we investigated the effect of blocking α4β7 function on the presence of intestinal T-lymphocytes in the diffuse lamina propria and the lymphoid aggregates in the uninflamed intestine, in the acute injury model DSS colitis and the chronic splenocyte transfer model. The presence of intestinal T-lymphocytes in the diffuse lamina propria and lymphoid aggregates was evaluated in wildtype mice, β7-/- mice, and wildtype mice given blocking antibodies to α4β7 or control antibodies using flow cytometry and immunohistochemistry. To evaluate the effect of α4β7 blockade in acute injury, the onset and regression of inflammation, lymphoid aggregate formation and regression and the presence of T-lymphocytes were evaluated in the acute injury model of DSS colitis during α4β7 blockade. To evaluate the effect of α4β7 blockade on T-cell mediated colitis, the course of colitis and the presence of T-lymphocytes in the diffuse lamina propria and lymphoid aggregates was evaluated in the splenocyte transfer model of colitis. In the unchallenged animals, the intestinal T-lymphocyte population in the diffuse lamina propria was normal in the absence of α4β7 function. The T-lymphocyte population in the lymphoid aggregates was also normal with the exception that the Foxp-3 T-lymphocyte population was significantly decreased in the absence of β7. DSS-induced colitis peaked at day 3 after the removal of as DSS demonstrated by increased histological score, MPO activity, and began to regress at day 7 after removal of DSS. The number of B-cell containing lymphoid aggregates peaked at 7 days after the removal of DSS and remained elevated at 14 days after the removal of DSS even though clinical inflammation had regressed. Anti-α4β7 blockade or loss of β7 function dramatically decreased the number B-cell containing lymphoid aggregates, but did not show any other effects, including changes in T-lymphocyte trafficking into the aggregates, during DSS-induced colitis. In the T-cell mediated splenocyte transfer model of colitis, the population of T-lymphocytes in the diffuse lamina propria and the lymphoid aggregates were significantly decreased in β7-/- mice and the wildtype mice receiving α4β7 blockade. This reduction corresponded to the decreased inflammation as evidenced by significant lower expression of TNF-α, IFN-γ, IL-6, MPO and IL-17. The presence of Foxp3+ T-lymphocytes in lymphoid aggregates is dependent upon α4β7, however the trafficking of other T-lymphocytes into the diffuse lamina propria and lymphoid aggregates in the basal state and during acute injury is not dependent upon α4β7. α4β7 blockade can block pathogenic T-lymphocyte trafficking to the intestine in a T-cell mediated model of colitis and accordingly is effective at ameliorating inflammation in this model. These observations suggest that α4β7 blockade may have fewer effects than anticipated on normal T-lymphocyte trafficking and T-lymphocyte trafficking during acute injury and may be a more specific therapy for T-cell mediated inflammatory diseases of the intestine.

Chlamydophila pneumoniae (Chlamydia pneumoniae) accelerates the formation of complex atherosclerotic lesions in Apo E3-Leiden mice.

Atherosclerosis is an inflammatory process and is characterised by the presence of T-lymphocytes in the lesions. To study the role of Chlamydophila pneumoniae (C. pneumoniae) in this process and the effect of infection on T-cell influx, we infected Apo E3-Leiden mice with C. pneumoniae and investigated the effect on lesion development and T-cell influx in atherosclerotic lesions at different time points post infection (pi). Nine week old mice, fed an atherogenic diet, were either mock-infected or infected with C. pneumoniae and sacrificed at 1, 6 and 9 months pi. Longitudinal sections of the aortic arches of the mice were stained with hematoxylin-eosin for atherosclerotic lesion type and lesion area analysis, or with rabbit-anti-CD3(+) to detect the presence of T-cells in the atherosclerotic lesions. T-cell influx was expressed as number of T-lymphocytes/lesion area. At 1 month pi, type 1, 2 and 3 lesions were present. At other time points pi, more complex lesion types 4, 5a and 5b were also present. Although infection did not influence the total lesion number or area, we observed an effect of C. pneumoniae infection on lesion type. Infection resulted in a significant shift in lesion formation from type 3 to type 4 (P=0.022) at 6 months pi, and from type 4 to type 5a (P=0.002) at 9 months pi. T-cells were observed at every time point pi. At 1 month pi, a significant increase in T-cell influx in the C. pneumoniae-infected atherosclerotic lesions was observed (P=0.0005). This study shows that C. pneumoniae infection enhances the inflammatory process by increasing T-lymphocytes in the plaque and accelerates the formation of complex lesions.

Effective treatment of experimental cytomegalovirus-induced encephalo-meningitis in immunocompromised rats with HPMPC

Cytomegalovirus (CMV)-induced encephalomeningitis is a dramatic complication in patients with the acquired immunodeficiency syndrome (AIDS) and treatment of this infection remains a major clinical problem. In order to study the pathogenesis and treatment of CMV-induced encephalomeningitis, we experimentally induced intracranial rat CMV (RCMV) infection in rats that were immunosuppressed by total body X-irradiation. CMV infection was monitored by viral plaque assay for estimation of the viral load. CMV-induced pathology, the presence of CMV-infected cells, as well as the presence of T-lymphocytes and monocytes/macrophages were studied by histopathologic and immunohistochemical staining techniques. The meninges showed CMV infection in mononuclear infiltrative cells and in endothelium of small blood vessels 8 days after intracerebral inoculation. This was accompagnied by multiple haemorraghes and inflammatory cell infiltration. The infection and inflammatory response persisted for at least 21 days p.i. Animals were treated with ( S)-1-(3-hydroxy-2-phosphonylmethoxypropyl)cytosine (HPMPC), 9-(1,3-dihydroxy-2-propoxymethyl)guanine (DHPG), hyperimmune serum (HIS) and both DHPG and HIS combined. Treatment with one dosage of HPMPC at 20 mg/kg effectively reduced virus titers. However, all other treatment modalities were not effective. In conclusion, the pathology of RCMV-induced encephalomeningitis in immunocompromised rats closely resembles that of AIDS patients. The infection is effectively treated by HPMPC.

Macrophage properties during peripheral nervous tissue rejection in vitro.

The present study introduces an in vitro model of xenogeneic peripheral nerve rejection to analyze the role of macrophages in this complex immunological situation. Nerve-sensitized mouse peritoneal exudate cells were co-cultured with rat peripheral nerve segments. The cultured rat nerve segments were fulminantly rejected in vitro by the co-cultured mouse peritoneal cell population. The massive tissue destruction included Schwann cell damage and was quite distinct from basic myelin phagocytosis observed during Wallerian degeneration in earlier experiments. The nerve-sensitized peritoneal exudate consisted of macrophages and T-cells. Antibody depletion experiments were performed to analyze T-lymphocyte effects in this model. Fulminant tissue rejection depended on the presence of T-lymphocytes in the culture medium. Their presence at the immediate site of tissue rejection, however, was not required. Further experiments were aimed at defining the role of T-cell-derived mediators during in vitro rejection. Depletion experiments using a panel of antibodies to cytokines revealed a critical involvement of IL-2, IL-3, IL-4, IL-6 and interferon-gamma in the induction of tissue rejection in vitro. Fulminant tissue rejection in vitro depended on the interaction of these cytokines with macrophages. The participation of macrophage surface receptors was studied in another series of experiments. The macrophage complement receptor type 3 was shown to be critically involved in the phagocytic attack during rejection. Antibodies to MHC class II antigens also abolished fulminant in vitro rejection, indicating that continuous antigen presentation is required in this process.

Expression of major histocompatibility antigens in human chronic pancreatitis.

T-lymphocytic infiltration of the exocrine pancreas and liver in patients with chronic pancreatitis has suggested that cell mediated immune mechanisms may play a part in the pathogenesis of this disease. As expression of major histocompatibility (MHC) antigens is a prerequisite for organ specific autoimmunity, the expression of HLA class I (beta 2-microglobulin) and class II (HLA-DR) determinants have been analysed, together with the presence of T-lymphocytes, in 93 patients (64 men and 29 women, mean age 40.6 years) having an operation for chronic pancreatitis. Ethanol (63 patients), recurrent acute pancreatitis (12), congenital lesions (2), and unknown (16) were suggested to be the causes of the disease. Immunohistochemical staining of formalin fixed and paraffin wax embedded tissue sections used conventional immunohistochemical techniques with specific anti-serum samples. No MHC expression was identified in 10 histologically normal pancreatic control specimens or in four cases of chronic pancreatitis secondary to obstruction by neuroendocrine tumours within the head of the pancreas. beta 2-microglobulin expression by pancreatic exocrine epithelial cells was seen in 76 chronic pancreatitis specimens (82%) while HLA-DR was present in 61 (66%). Simultaneous expression of both class I and II determinants was seen in 53 (57%) of cases. MHC determinant expression was not found in 10 cases (11%) of chronic pancreatitis. In the positive specimens, expression was confined to ductal and ductular (interlobular and intralobular) epithelium with no staining of acinar cells. Staining was not related to the suspected cause of the disease or age. T-lymphocytes were more prominent in chronic pancreatitis mean (SEM) (131 (15) cells per high powered field) than controls (5 (1), p < 0.01). Aberrant MHC expression by exocrine pancreatic epithelial cells occurring in the presence of an appreciable T-cell infiltration confirmed that the appropriate cellular conditions were present for cell mediated cytotoxicity to contribute to the pathogenesis of chronic pancreatitis.

T cells and monocytes regulate the generation and functional activity of natural killer-derived lymphokine-activated killer cells.

The lymphokine-activated killer (LAK) phenomenon is generally referred to as nonspecific, i.e., major histocompatibility complex (MHC)-unrestricted cytotoxicity against tumor cells generated by ex vivo culture of human peripheral blood lymphocytes with interleukin 2 (IL-2). In this study, we selectively purified and depleted cell subpopulations such as natural killer (NK) cells, T-lymphocytes and monocytes from fresh human peripheral blood by negative selection. While highly purified NK cells could be induced to acquire potent LAK activity in five-day culture with IL-2, the presence of T-lymphocytes and monocytes in NK cultures was needed in order to induce a significant expansion of cytotoxic effector cells over the culture period. Neither T cells nor monocytes by themselves were able to generate LAK cells in a standard five-day IL-2 culture. However, when added to highly purified NK cells prior to IL-2 incubation, a proportion of CD3+ T-lymphocytes was found to gain LAK-like killing activity. Monocytes, when cultured with IL-2 in the presence of NK cells and T-lymphocytes, did not appear to acquire LAK activity but were able to induce a dramatic increase in cytotoxic lymphocyte recovery after five days with IL-2. In summary, we could demonstrate that peripheral blood T-lymphocytes and monocytes are potent regulators of NK-dependent lymphokine (IL-2)-activated killing.

Cytokine gene expression in primary brain tumours, metastases and meningiomas suggests specific transcription patterns

To obtain an insight into the network of cytokine gene transcription in the brain tumour microenvironment, we investigated the expression of genes encoding for interleukin (IL)-1α, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-10, interferon (IFN)-γ, granulocyte-macrophage colony-stimulating factor, tumour necrosis factor (TNF)-α and transforming growth factor (TGF)-β1, -β2 and -β3 in freshly excised brain tumour samples and autologous peripheral blood mononuclear cells. Tissue specimens from 15 primary brain tumours, three brain metastases, five meningiomas, autologous peripheral blood mononuclear cells (PBMC) and three brain tumour cell lines were tested by reverse polymerase chain reaction. Despite the presence of T-lymphocytes, cytokine gene transcripts typically detectable upon T cell receptor triggering could not be observed in central nervous system tumours of diverse histology. In primary brain neoplasms, transcription of genes encoding for the inhibitory cytokines TGF-β and IL-10 was detectable in more than 50% of samples. IL-6 transcripts could only be detected in malignant gliomas. In brain metastases, virtually no cytokine gene transcripts could be observed. Surprisingly, TGF-β transcripts were also detected in all meningiomas. Thus, transcription of genes encoding for inhibitory factors appears to prevail in primary brain neoplasms.

Site of action of 9-/1,3-dihydroxy-2-propoxymethyl/guanine/DHPG/ in the virus replication cycle

Cytomegalovirus (CMV)-induced encephalomeningitis is a dramatic complication in patients with the acquired immunodeficiency syndrome (AIDS) and treatment of this infection remains a major clinical problem. In order to study the pathogenesis and treatment of CMV-induced encephalomeningitis, we experimentally induced intracranial rat CMV (RCMV) infection in rats that were immunosuppressed by total body X-irradiation. CMV infection was monitored by viral plaque assay for estimation of the viral load. CMV-induced pathology, the presence of CMV-infected cells, as well as the presence of T-lymphocytes and monocytes/macrophages were studied by histopathologic and immunohistochemical staining techniques. The meninges showed CMV infection in mononuclear infiltrative cells and in endothelium of small blood vessels 8 days after intracerebral inoculation. This was accompagnied by multiple haemorraghes and inflammatory cell infiltration. The infection and inflammatory response persisted for at least 21 days p.i. Animals were treated with (S)-1-(3-hydroxy-2-phosphonylmethoxypropyl)cytosine (HPMPC), 9-(1,3-dihydroxy-2-propoxymethyl)guanine (DHPG), hyperimmune serum (HIS) and both DHPG and HIS combined. Treatment with one dosage of HPMPC at 20 mg/kg effectively reduced virus titers. However, all other treatment modalities were not effective. In conclusion, the pathology of RCMV-induced encephalomeningitis in immunocompromised rats closely resembles that of AIDS patients. The infection is effectively treated by HPMPC.

Metabolism and subcellular localization of angiotensin converting enzyme in cultured human monocytes

The enhancement of monocyte ACE activity during culture by autologous T-lymphocytes was shown to be due to a stimulation of the rate of ACE synthesis. The rate of synthesis increased from 0.020 mU/10 6 monocytes/hr in monocytes cultured alone to 0.063 mU/10 6 monocytes/hr in monocytes co-cultured with T-lymphocytes. The presence of T-lymphocytes during culture did not alter the rate of ACE degradation observed in monocytes cultured alone. The ACE induced in monocytes by T-lymphocytes appears to be an ecto-enzyme. Brief exposure to diazosulfanilic acid (10 −3 M) and papain (250 ug/ml) reduced ACE activity 89% and 66%, respectively, without appreciably altering the activity of the cytosolic enzyme, lactate dehydrogenase.

Monocytes direct T lymphocyte stimulation of human peripheral blood granulocyte-macrophage colony formation.

The committed granulocyte-macrophage progenitor cell (or colony-forming unit, CFU-GM) differentiates in vitro under the influence of the soluble glycoprotein factor(s) termed colony stimulating activity (GM-CSA), which can be derived from several cellular sources, including normal human peripheral blood mononuclear cells (PBMNC). We have investigated the respective roles of the monocyte and T lymphocyte components of PBMNC in generating GM-CSA using as an assay CFU-GM colony formation by purified peripheral blood null cells. Highly purified unstimulated T-lymphocytes did not themselves stimulate null cell CFU-GM colony formation, but when monocytes were also included, large numbers of colonies were observed, far greater than those stimulated by monocytes alone. This synergism was independent of HLA phenotype, occurring with T-lymphocyte and monocyte fractions from unrelated donors. Media conditioned by unstimulated purified monocytes promoted CFU-GM colonies from null cells only in the presence of T-lymphocytes, suggesting that monocytes produce a factor directing the synthesis and/or release of GM-CSA by T cells.

T-lymphocyte and B-lymphocyte dichotomy in anuran amphibians: I. T-lymphocyte proportions, distribution and ontogeny, as measured by E-rosetting, nylon wool adherence, postmetamorphic thymectomy, and non-specific esterase staining

We used sheep erythrocyte (SRBC) E-rosetting, nylon wool fractionation thymectomy and nonspecific esterase staining to assess T-lymphocyte characteristics in Rana pipiens during various developmental stages. T-lymphocytes appear in the spleens of premetamorphic tadpoles. We found significant levels of lymphocytes classifiable as T-cells in the peripheral blood of adults, but fewer numbers of T-cells in the thymus, jugular bodies, spleen, pronephros, mesonephros, liver and bone marrow. In addition, thymectomized Xenopus laevis showed a sharp decrease in T-cells as evidenced by E-rosetting, ANAE stain and nylon wool fractionation. The presence of T-lymphocytes in anuran amphibians and the existence of a receptor for SRBC on a population of these cells, suggest conservation of T-cells during evolution.

T-cell subsets and langerhans cells in wart lesions

The presence of T-lymphocytes and Langerhans cells was assessed on tissue sections of 28 human warts from various localizations and in normal epidermis by indirect immunofluorescence using specific monoclonal antibodies. In most cases, the density of Langerhans cells was dramatically reduced in wart epidermis as compared to normal epidermis and a mild cellular infiltrate could be noted. In some lesions, OKT4 and OKT8 cell populations were present and the number of Langerhans cells was high both in dermis and epidermis. These data are compatible with the role of Langerhans cells and the existence of a local cellular immune reaction in human papilloma virus-infected tissues. No correlation could yet be established with the virus type on the skin localization.

Kinetics of protein a activation of mononuclear cells from patients with chronic lymphocytic leukemia — I. CLL B-cells are not intrinsically unresponsive to staphylococcal protein A

The response of lymphocyte subpopulations to staphylococcal Protein A (SPA) was studied in patients with B-cell chronic lymphocytic leukemia (CLL) and normal volunteers. The kinetics of the proliferative response, optimal dose and sera requirements were determined. Of 92 experiments conducted in 60 patients, SPA induced peripheral blood mononuclear cells (PBMC) proliferation in 81.5% of cases studied. The mean proliferative response of CLL PBMC was significantly lower than normal PBMC, 5823 vs. 30,364 cpm. However, enriched CLL B-cells failed to respond to SPA compared to normal enriched B-cells, with mean cpm 444 vs. 6438 respectively. As PBMC from CLL consist of increased proportions of B-cells and decreased proportions of T-cells, enriched CLL B-cells were cultured at 1 : 1 ratio with autologous or allogeneic normal T-cell enriched fractions. CLL B-lymphocytes were stimulated by SPA when cultured in the presence of T-lymphocytes, indicating a T-helper defect in the B-CLL proliferative response to SPA, rather than an intrinsic inability of CLL B-cells to proliferate. These observations are of import for further studies of CLL B-lymphocyte function, cytogenetics, and establishment of CLL B-cell lines in culture.

In vitro synthesis of immunoglobulins and IgM-rheumatoid factor by blood mononuclear cells of patients with rheumatoid arthritis.

In vitro synthesis of IgG, IgM and IgM-rheumatoid factor (IgM-RF) was investigated in unstimulated and pokeweed mitogen (PWM)-stimulated 7-day cultures of blood mononuclear cells (BMC) from 28 seropositive patients with active rheumatoid arthritis (RA), in a second group of 13-day cultures from 94 unselected rheumatoid patients, and in 21 healthy controls. Both normal and rheumatoid BMC cultures synthesized IgM-RF in response to PWM stimulation. Mitogen-induced stimulation was shown to be dependent on the presence of T-lymphocytes. PWM-induced IgM and IgM-RF synthesis were reduced in BMC from rheumatoid patients in comparison with healthy controls. However, the fraction of IgM-RF in the total IgM synthesized was significantly higher in the RA supernatants than in the controls, suggesting the presence of a larger precursor B-cell population committed to IgM-RF synthesis in those cultures. BMC from 44 of the 94 patients demonstrated spontaneous synthesis of IgM-RF, and this was positively correlated with disease activity and rheumatoid factor titer. Spontaneous production was shown to reside in the T-lymphocyte depleted, adherent cell-depleted, B-cell subpopulation. It is concluded that in active RA there is a specific activation and expansion of the circulating B-cell subpopulation committed to IgM-RF synthesis, possibly due to abnormal immunoregulatory mechanisms modulating synthesis of this antibody.

Intestinal mast cell response in thymectomised and normal mice infected with [formula omitted

In NIH mice, expulsion of Trichinella spiralis from the small intestine and increase in intestinal mast cells were each dependent on the presence of T-lymphocytes. Both changes were deficient in thymectomised mice but could be largely restored by reconstitution of thymectomised mice with syngeneic mesenteric lymph node cells. In both NIH and BALB/C mice the majority of the increased number of mast cells occurred within the intestinal epithelium. In NIH mice increase in the number of intestinal mast cells coincided roughly with expulsion of the parasites. In BALB/C mice increase in the numbers of intestinal mast cells did not appear to be connected with the location or expulsion of parasites and it is concluded that mast cell proliferation, accumulation and discharge per se do not result in or from worm expulsion.