Cytotoxic lymphocytes in B-cell chronic lymphocytic leukemia. A flow cytometric study of peripheral blood, lymph nodes and bone marrow.

The occurrence of cytotoxic lymphocyte subpopulations (i.e., CD 16+, CD 57+ and cytotoxic CD 8+) wa studied in the peripheral blood of 18 B-cell chronic lymphocytic leukemia (B-CLL) patients. The absolute numbers of CD 57+, CD 16+ and cytotoxic CD 8+ lymphocytes were increased in the peripheral blood of untreated patients as compared with healthy donors, suggesting a causal relation with the accumulation of malignant B-cells. For 5 B-CLL patients and 5 hematological normal donors, the lymphocyte subpopulations in peripheral blood, lymph nodes and bone marrow were determined. A significant immune response was observed in the lymph nodes of the patients, as reflected by the CD 3+ lymphocytes, which were 1.7-27 times larger in the patients lymph nodes than in their peripheral blood and bone marrow. In contrast, with peripheral blood this was mainly caused by an increase in CD 4+ lymphocytes. The CD 57 lymphocytes in the lymph nodes of the patients had abnormal orthogonal light-scattering signals and an abnormal density of CD 57+ receptors in comparison with their peripheral blood CD 57+ lymphocytes or the CD 57+ lymphocytes in the peripheral blood, bone marrow and tonsils of the hematological normal donors. This study shows that although a significant increase of cytotoxic lymphocytes in the peripheral blood of B-CLL patients is observed, the actual distributions of the non-malignant lymphocytes can be quite different at the actual tumor sites, i.e., bone marrow and lymph nodes.     

Lymphocyte traffic through lymph nodes and Peyer's patches of the rat: B- and T-cell-specific migration patterns within the tissue,and their dependence on splenic tissue

The migration routes of lymphocyte subsets through organ compartments are of importance when trying to understand the local events taking place during immune responses. We have therefore studied the traffic of B, T, CD4⁺, and CD8⁺ lymphocytes through lymph nodes and Peyer's patches. At various time points after injection into the rat, labeled lymphocytes were localized, and their phenotype characterized in cryostat sections using immunohistochemistry. Morphometry was also performed, and the recovery of ⁵¹Cr-labeled lymphocytes in these organs was determined. B and T lymphocytes entered the lymph nodes via the high endothelial venules in similar numbers. Most B lymphocytes migrated via the paracortex (T cell area) into the cortex (B cell area), and then back in substantial numbers into the paracortex. In contrast, T lymphocytes predominantly migrated into the paracortex and were rarely seen in the cortex. No obvious differences were seen between various lymph nodes and Peyer's patches and the routes of CD4⁺ and CD8⁺ lymphocytes. After injection of lymphocytes into animals with autotransplanted splenic tissue, the number of B lymphocytes that had migrated into the B cell area of lymph nodes and of Peyer's patches was significantly decreased, whereas CD4⁺ lymphocytes migrated in larger numbers into the T cell area of both organs.This study was supported by the Deutsche Forschungsgemein-schaft (SFB 244, A7).     

Lymphocyte subpopulations in lymph nodes and peripheral blood: a comparison between patients with stable angina and acute coronary syndrome

Objective

Atherosclerosis is characterized by a chronic inflammatory response involving activated T cells and impairment of natural killer (NK) cells. An increased T cell activity has been associated with plaque instability and risk of acute cardiac events. Lymphocyte analyses in blood are widely used to evaluate the immune status. However, peripheral blood contains only a minor proportion of lymphocytes. In this study, we hypothesized that thoracic lymph nodes from patients with stable angina (SA) and acute coronary syndrome (ACS) might add information to peripheral blood analyses.

Methods

Peripheral blood and lymph nodes were collected during coronary by-pass surgery in 13 patients with SA and 13 patients with ACS. Lymphocyte subpopulations were assessed by flow cytometry using antibodies against CD3, CD4, CD8, CD19, CD16/56, CD25, Foxp3, CD69, HLA-DR, IL-18 receptor (R) and CCR4.

Results

Lymph nodes revealed a lymphocyte subpopulation profile substantially differing from that in blood including a higher proportion of B cells, lower proportions of CD8⁺ T cells and NK cells and a 2-fold higher CD4/CD8 ratio. CD4⁺CD69⁺ cells as well as Foxp3⁺ regulatory T cells were markedly enriched in lymph nodes (p<0.001) while T helper 1-like (CD4⁺IL-18R+) cells were more frequent in blood (p<0.001). The only significant differences between ACS and SA patients involved NK cells that were reduced in the ACS group. However, despite being reduced, the NK cell fraction in ACS patients contained a significantly higher proportion of IL-18R⁺ cells compared with SA patients (p<0.05).

Conclusion

There were several differences in lymphocyte subpopulations between blood and lymph nodes. However, the lymphocyte perturbations in peripheral blood of ACS patients compared with SA patients were not mirrored in lymph nodes. The findings indicate that lymph node analyses in multivessel coronary artery disease may not reveal any major changes in the immune response that are not detectable in blood.     

In vivo VL-targeted activation-induced apoptotic supraclonal deletion by a microbial B cell toxin

To interfere with host immune responses, some microbial pathogens produce proteins with the properties of superantigens, which can interact via conserved V region framework subdomains of the Ag receptors of lymphocytes rather than the complementarity-determining region involved in the binding of conventional Ags. In recent studies, we have elucidated how a model B cell superantigen affects the host immune system by targeting a conserved V(H) site on the Ag receptors of B lymphocytes. To determine whether these findings represent a general paradigm, we investigated the in vivo immunobiologic properties of protein L of Peptostreptococcus magnus (PpL), a microbial Ig-binding protein specific for a V region site on Ig L chains. Our studies confirmed that PpL binding is restricted to a subset of murine Vkappa-expressing B cells, and found that B cells with stronger PpL-binding activity are associated with certain B cell subsets: splenic marginal zone (CD21(high) CD23(low)), splenic CD1(+), peritoneal B-1a (IgD(low) CD5(+)), and CD21(high) CD24(high) B cells in peripheral lymph nodes, mesenteric lymph nodes, and Peyer's patches. Infusion of PpL triggered a sequence of events in B cell receptor (BCR)-targeted B cells, with rapid down-regulation of BCR, the induction of an activation phenotype, and limited rounds of proliferation. Apoptosis followed through a process heralded by the dissipation of mitochondrial membrane potential, the induction of the caspase pathway, DNA fragmentation, and the deposition of B cell apoptotic bodies. These studies define a common pathway by which microbial toxins that target V region-associated BCR sites induce programmed cell death.     

The entry of T and B lymphocytes into rat popliteal lymph nodes undergoing a graft-versus-host reaction

The entry of radiolabeled blood-borne T and B lymphocytes into resting popliteal lymph nodes and popliteal lymph nodes stimulated with semiallogeneic lymphocytes was investigated in rats. Thoracic duct lymphocytes separated into T- and B-lymphocyte populations on nylon-wool columns were radiolabeled with 51chromium and equal numbers of T or B lymphocytes were injected intravenously. While the ratio of T and B lymphocytes in the blood is approximately 3:1 it was found that the ratio of T to B lymphocytes migrating into lymph nodes was approximately 9 T to 1 B lymphocyte in both resting and antigenically stimulated lymph nodes. Since the ratio of T to B lymphocytes in thoracic duct lymph is similar to that of blood, there is a disparity between the number of T cells entering and leaving lymph nodes. These results suggest that some T lymphocytes may return to the blood directly and/or there is increased T lymphocyte death in lymph nodes.     

Human immunodeficiency virus type 1 bound to B cells: relationship to virus replicating in CD4+ T cells and circulating in plasma

Human immunodeficiency virus type 1 (HIV-1) virions bind to B cells in the peripheral blood and lymph nodes through interactions between CD21 on B cells and complement-complexed virions. B-cell-bound virions have been shown to be highly infectious, suggesting a unique mode of HIV-1 dissemination by B cells circulating between peripheral blood and lymphoid tissues. In order to investigate the relationship between B-cell-bound HIV-1 and viruses found in CD4+ T cells and in plasma, we examined the genetic relationships of HIV-1 found in the blood and lymph nodes of chronically infected patients with heteroduplex mobility and tracking assays and DNA sequence analysis. In samples from 13 of 15 patients examined, HIV-1 variants in peripheral blood-derived B cells were closely related to virus in CD4+ T cells and more divergent from virus in plasma. In samples from five chronically viremic patients for whom analyses were extended to include lymph node-derived HIV-1 isolates, B-cell-associated HIV-1 and CD4+-T-cell-associated HIV-1 in the lymph nodes were equivalent in their divergence from virus in peripheral blood-derived B cells and generally more distantly related to virus in peripheral blood-derived CD4+ T cells. These results indicates virologic cross talk between B cells and CD4+ T cells within the microenvironment of lymphoid tissues and, to a lesser extent, between cells in lymph nodes and the peripheral blood. These findings also indicate that most of the virus in plasma originates from cells other than CD4(+) T cells in the peripheral blood and lymph nodes.     

肺癌患者外周血T淋巴细胞分型与抗核抗体之间的关系研究

摘要 目的：研究肺癌患者外周血T淋巴细胞分型与抗核抗体之间的关系。方法：选择2019年1月到2021年6月在我院接受治疗的肺癌患者81例作为研究组,并选择同期健康志愿者81例作为对照组,检测并比较两组患者外周血CD4⁺、CD8⁺和CD4⁺/CD8⁺淋巴细胞比例,以及抗核抗体血清滴度。比较不同抗核抗体、年龄、性别、TNM分期、肿瘤分化程度以及病理类型肺癌患者外周血CD4⁺、CD8⁺和CD4⁺/CD8⁺淋巴细胞比例。结果：（1）肺癌患者外周血CD4⁺和CD4⁺/CD8⁺淋巴细胞比例显著低于对照组,而CD8⁺淋巴细胞比例显著高于对照组（P<0.05）;（2）III+IV肺癌患者外周血CD4⁺、和CD4⁺/CD8⁺淋巴细胞比例均显著低于I+II肺癌患者,而CD8⁺淋巴细胞比例均显著高于I+II肺癌患者（P<0.05）;（3）小细胞肺癌患者外周血CD4⁺、和CD4⁺/CD8⁺淋巴细胞比例均显著低于非小肺癌患者,而CD8⁺淋巴细胞比例均显著高于非小肺癌患者（P<0.05）;（4）肺癌患者抗核抗体血清滴度显著高于对照组（P<0.05）;（5）抗核抗体阳性患者CD4⁺和CD4⁺/CD8⁺淋巴细胞亚群比例均显著低于抗核抗体阴性患者,而CD8⁺淋巴细胞亚群比例显著高于抗核抗体阴性患者（P<0.05）。结论：肺癌患者外周血T淋巴细胞亚群表达异常,并且其表达水平可能与抗核抗体滴度有关。     

FOXP3+ Lymphocyte Density in Pancreatic Cancer Correlates with Lymph Node Metastasis

Objective

To determine if the density of FOXP3⁺ lymphocytes in primary tumors and lymph nodes in pancreatic cancer correlates with the presence of lymph node metastases.

Methods

FOXP3⁺ lymphocyte density in primary pancreatic cancer tissue and draining lymph nodes was measured using immunohistochemistry. We analyzed the clinical and pathological aspects associated with the accumulation of FOXP3⁺ lymphocytes in pancreatic cancer. We also analyzed the correlation of density of FOXP3⁺ lymphocytes in lymph nodes with the nodal status and distance from the primary tumor.

Results

FOXP3⁺ lymphocyte density in pancreatic cancer was significantly higher than in paratumoral pancreatic tissue. The density of FOXP3⁺ lymphocytes in local tumor tissue correlated significantly with the histological grade and overall lymph node status. Furthermore, FOXP3⁺ lymphocyte density was significantly higher in positive lymph nodes than in negative ones, while it had no correlation with the distance of the lymph node from the primary tumor.

Conclusion

FOXP3⁺ lymphocyte density in primary tumor tissue in patients with pancreatic cancer correlates with lymph node metastasis. Lymph nodes containing metastases having higher FOXP3⁺ lymphocyte densities than do negative lymph nodes.     

Effect of sizofiran on regional lymph nodes in patients with head and neck cancer

The immunomodulating effects of preoperative sizofiran (SPG) administration on regional lymph nodes were studied in patients with stage III or IV head and neck cancer, by comparing the immunofunction of peripheral blood. The regional lymph nodes were dissected surgically, and freshly obtained mononuclear cells were studied to investigate the interleukin-2 (IL-2) production, the LAK and NK activities, and the quantitative analysis of the surface phenotype of the mononuclear cells. The results indicated that SPG enhanced immunological activities in the regional lymph nodes, as shown by increased IL-2 production and cytotoxic activities of the effector cells (NK, LAK), and increased helper T lymphocytes (CD4⁺) in the tumor-uninvolved lymph nodes. The immunofunction following SPG administration was attenuated, but was still augmented in the regional lymph nodes with metastases. Therefore, SPG was found to be a biologic response modifier to enhance the immunofunctions of the regional lymph node in patients with head and neck cancer.     

Influence of aging on intracellular free calcium and proliferation of mouse T-cell subsets from various lymphoid organs.

The influence of aging on T-cell activation and proliferation was examined in lymphocytes derived from peripheral blood, spleen, and lymph nodes of WBB6F1 C57B1/6J x WB/Re) mice. Following activation with anti-CD3 monoclonal antibodies, the greatest age-related changes were seen in CD4+ cells derived from spleens of 27- to 30-month-old mice. These CD4+ lymphocytes showed reduced [Ca2+]i signaling and decreased proliferation in the presence of exogenous interleukin 2. CD8+ cells from spleens of old animals showed reduced [Ca2+]i but not altered proliferation. Both CD4+ and CD8+ cells derived from peripheral blood of old mice showed decreased peak [Ca2+]i, but no defect in cell proliferation. In contrast, age-related deficits in either [Ca2+]i or proliferation were not observed in CD4+ and CD8+ cells from lymph nodes. Additionally, the percentage of CD4+ cells was decreased in all lymphoid organs from old mice, while the percentage of CD8+ cells was similar in lymphoid organs of old and young mice. Old mice had a significant increase in expression of Pgp-1 in CD4+ cells from spleen and peripheral blood and CD8+ cells derived from lymph node. Our studies indicate that there are differential effects of aging in T lymphocytes derived from different lymphoid organs in mice. Among the cell sources and subsets examined, the age-related changes noted in CD4+ cells from mouse peripheral blood were the most similar to those previously observed in the corresponding peripheral blood lymphocyte subset in humans.     

The Activation Pattern of Blood Leukocytes in Head and Neck Squamous Cell Carcinoma Is Correlated to Survival

Head and neck squamous cell carcinoma (HNSCC) is known to cause substantial immunosuppression. The present study was designed to characterize blood leukocyte activation in HNSCC and to investigate if the individual activation pattern could be related to tumor progress and survival. The leukocyte activation profile of HNSCC patients and healthy controls was assessed with flow cytometry. HNSCC patients displayed increased numbers of monocytes, neutrophils and total leukocytes as well as an enhanced neutrophil/lymphocyte ratio. In addition, patients had a higher percentage of CD69⁺, CD71⁺ and CD98⁺ T cell subsets and NK cells, and a reduced expression of L-selectin in CD14^highCD16⁺ monocytes and neutrophils, when compared to controls. These changes could be correlated to both tumor burden and spread to lymph nodes. Among the cancer patients an increased neutrophil/lymphocyte ratio, a low neutrophil and CD14^high CD16⁺ monocyte activation state and an elevated CD4/CD8 ratio were related to poor survival. In contrast, a high percentage of CD98⁺ Th cells appeared to be associated with a better outcome. Taken together, the present data indicate that HNSCC causes activation of blood leukocytes and that the individual activation pattern can be linked to prognosis.     

PNA-binding glycans are expressed at high levels on horse mature and immature T lymphocytes and a subpopulation of B lymphocytes

In mammals, the binding of peanut agglutinin (PNA) on the plasma membrane defines subpopulations among lymphocytes from peripheral blood and lymphoid organs. PNA binds Gal 1,3GalNAc residues provided that they are not sialylated. Here, we studied the expression of PNA-binding glycans on healthy horse peripheral blood, thymus, lymph node and spleen lymphocytes. We first demonstrated the binding specificity of PNA for galactose residues by competition experiments and the inhibitory role of sialic acids in PNA binding by sialidase digestion. Unlike human and murine lymphocytes, all equine lymphocytes were found positive by flow cytometry analysis. Double-staining analyses showed that lymphocytes expressing high levels of PNA-binding glycans (PNA^high lymphocytes) were made up of the great majority of CD5⁺, CD4⁺ and CD8⁺ cells, and of 30 and 50% of sIg-bearing lymphocytes in peripheral blood and in lymph nodes or spleen, respectively. Lectin histochemistry suggested that lymph node germinal centres contained PNA^high B cells. Contrary to what is found in humans and mice, PNA staining intensity on CD5⁺, CD4⁺ and CD8⁺ cells did not differentiate immature from mature T lymphocytes in the equine thymus. The functional consequences of these differences are discussed. Published in 2005.     

CD73-generated adenosine restricts lymphocyte migration into draining lymph nodes

After an inflammatory stimulus, lymphocyte migration into draining lymph nodes increases dramatically to facilitate the encounter of naive T cells with Ag-loaded dendritic cells. In this study, we show that CD73 (ecto-5'-nucleotidase) plays an important role in regulating this process. CD73 produces adenosine from AMP and is expressed on high endothelial venules (HEV) and subsets of lymphocytes. Cd73(-/-) mice have normal sized lymphoid organs in the steady state, but approximately 1.5-fold larger draining lymph nodes and 2.5-fold increased rates of L-selectin-dependent lymphocyte migration from the blood through HEV compared with wild-type mice 24 h after LPS administration. Migration rates of cd73(+/+) and cd73(-/-) lymphocytes into lymph nodes of wild-type mice are equal, suggesting that it is CD73 on HEV that regulates lymphocyte migration into draining lymph nodes. The A(2B) receptor is a likely target of CD73-generated adenosine, because it is the only adenosine receptor expressed on the HEV-like cell line KOP2.16 and it is up-regulated by TNF-alpha. Furthermore, increased lymphocyte migration into draining lymph nodes of cd73(-/-) mice is largely normalized by pretreatment with the selective A(2B) receptor agonist BAY 60-6583. Adenosine receptor signaling to restrict lymphocyte migration across HEV may be an important mechanism to control the magnitude of an inflammatory response.     

Nonrandom migration of CD4+, CD8+, and gamma delta+T19+ lymphocyte subsets following in vivo stimulation with antigen

We report here the results of experiments in which the migration of three T cell subsets (CD4+, CD8+, and gamma delta+T19+ cells) through antigen-stimulated lymph nodes and subcutaneous granulomas has been compared with that through normal skin and resting lymph nodes. The percentage of gamma delta+T19+ lymphocytes was halved and the percentage of CD8+ lymphocytes was doubled in lymph draining stimulated compared with control tissues, and all lymphocyte subsets except gamma delta+T19+ lymphocytes had higher hourly outputs in lymph draining antigen-stimulated compared with control tissues. Antigen also resulted in a higher percentage of CD8+ lymphoblasts and a lower percentage of gamma delta+T19+ lymphoblasts in efferent lymph draining antigen-stimulated lymph nodes. The data indicate that lymphocyte subsets leave the blood with differing efficiencies in different vascular beds and raise the possibility that antigen can influence the rate at which tissues extract individual T cell subsets from the blood.     

Jaagsiekte retrovirus is widely distributed both in T and B lymphocytes and in mononuclear phagocytes of sheep with naturally and experimentally acquired pulmonary adenomatosis

Jaagsiekte sheep retrovirus (JSRV) is a type D retrovirus specifically associated with a contagious lung tumor of sheep, sheep pulmonary adenomatosis (SPA). JSRV replicates actively in the transformed epithelial cells of the lung, and JSRV DNA and RNA have been detected in lymphoid tissues of naturally affected animals. To determine the lymphoid target cells of JSRV, CD4(+) T cells, CD8(+) T cells, B lymphocytes, and adherent cell (macrophage/monocyte) populations were isolated from the mediastinal lymph nodes of naturally affected sheep and lambs inoculated with JSRV. Cells were enriched to high purity and then analyzed for JSRV proviral DNA by heminested PCR, and the proviral burden was quantitated by limiting dilution analysis. JSRV proviral DNA was found in all subsets examined but not in appropriate negative controls. In sheep naturally affected with SPA, JSRV proviral burden was greatest in the adherent cell population. In the nonadherent lymphocyte population, surface immunoglobulin-positive B cells contained the greatest proviral burden, while CD4(+) and CD8(+) T cells contained the lowest levels of JSRV proviral DNA. In most of the cases (5 of 8), provirus also could be detected in the peripheral blood mononuclear cell (PBMC) population. A kinetic study of JSRV infection in the mediastinal lymphocyte population of newborn lambs inoculated with JSRV found that JSRV proviral DNA could be detected as early as 7 days postinoculation before the onset of pulmonary adenomatosis, although the proviral burden was greatly reduced compared to adult natural cases. This was reflected in the levels found in PBMC since proviral DNA was detected in 2 of 13 animals. At the early time points studied (7 to 28 days postinoculation) no one subset was preferentially infected. These data indicate that JSRV can infect lymphoid and phagocytic mononuclear cells of sheep and that dissemination precedes tumor formation. Infection of lymphoid tissue, therefore, may play an important role in the pathogenesis of SPA.     

Identification of select lymphocyte homing molecules and vascular addressins in lymphotoxin-alpha deficient mice

The transmigration of lymphocytes across vascular endothelium is a critical step for the localization of lymphocytes to lymph nodes in both naive and immune reactive states. Mice deficient in lymphotoxin-alpha (LT-alpha) lack peripheral and gut associated lymph nodes. Lymphocyte function and homing ability are reported to be normal in these mice yet information regarding cell adhesion molecules and counterpart vascular addressins is lacking. The phenotype of peripheral lymphocytes from LT-alpha deficient mice was investigated by the use of fluorescent activated cell sorting and immunohistochemistry. No difference was detected in the splenocyte and tissue expression of L-selectin, alpha4beta7 or its individual integrin components, mucosal addressin cell adhesion molecule (MAdCAM-1), intracellular adhesion molecule (ICAM-1), peripheral node addressin (PNAd), or platelet/endothelial cell adhesion molecule (PECAM-1) between wild-type and LT-alpha deficient mice. Therefore, impaired expression of these lymphocyte homing and vascular addressin molecules is apparently not included in the phenotype of the LT-alpha deficient mouse.     

Antigen-driven oligoclonal expansion of tumor-infiltrating B cells in infiltrating ductal carcinoma of the breast

The objective of this study was to determine whether tumor-infiltrating B cells (TIL-B) of infiltrating ductal carcinoma (IDC) of the breast represent a tumor-specific humoral immune response. Immunohistochemical analysis of three Her-2/neu-negative IDC tumors from geriatric patients showed that TIL-B cluster in structures similar to germinal centers containing CD20(+) B lymphocyte and CD3(+) T lymphocyte zones with interdigitating CD21(+) follicular dendritic cells, suggesting an in situ immune response. A total of 29, 31, and 58 IgG1 H chain clones was sequenced from the three IDC tumors, respectively. Intratumoral oligoclonal expansion of TIL-B was demonstrated by a preponderance (45-68%) of clonal B cells. In contrast, only 7% of tumor-draining lymph node and 0% of healthy donor PBL IgG H chains were clonal, consistent with the larger repertoires of node and peripheral populations. Patterns and levels of TIL-B IgG H chain somatic hypermutation suggested affinity maturation in intratumoral germinal centers. To examine the specificity of TIL-B Ig, a phage-displayed Fab library was generated from the TIL-B of one IDC tumor. Panning with an allogeneic breast cancer cell line enriched Fab binding to breast cancer cells, but not nonmalignant cell lines tested. However, panning with autologous tumor tissue lysate increased binding of Fab to both tumor tissue lysate and healthy breast tissue lysate. These data suggest an in situ Ag-driven oligoclonal B cell response to a variety of tumor- and breast-associated Ags.     

Lymphocyte subpopulations of regional lymph nodes in human colon and gastric adenocarcinomas

 In order to study the host immune response to tumours, previous knowledge of the cellular composition of regional draining lymph nodes is necessary. Enlarged regional lymph nodes are a common finding in colon and gastric adenocarcinomas. We have studied the cellular composition of normal non-reactive and of regional draining lymph nodes of colon and gastric adenocarcinomas. In normal non-reactive lymph nodes, T lymphocytes (CD2⁺, CD7⁺) constituted the largest fraction of the lymphoreticular cells. These lymphocytes were mainly CD4⁺, and there were more cells expressing the CD45RA isoform of the CD45 antigen than CD45RO. Reactive lymph nodes presented a decreased proportion of CD4⁺ CD45RA⁺ cells and an increased number of B cells. Although most of the T cells in the reactive nodes were CD4⁺ CD45RO⁺, their proportion was similar to that found in normal non-reactive nodes. We studied the presence of the molecules CD28 and CD80 involved in the processes of interaction and activation of T and B lymphocytes. The CD28 molecule was found in all the T lymphocytes, while the CD80 molecule was weakly expressed on the B lymphocyte membrane. Received: 4 January 1996 / Accepted: 28 May 1996     

Human lymphocyte-high endothelial venule interaction: organ-selective binding of T and B lymphocyte populations to high endothelium

We wished to determine whether human lymphocytes, like their murine counterparts, show organ-specific interactions with high endothelial venules (HEV). Functional HEV-binding ability was measured by an in vitro assay of lymphocyte adherence to HEV in frozen sections of human lymphoid tissues which was adapted from rodent systems. It was found that human lymphocytes bind selectively to HEV and that, whereas mature T lymphocytes bind preferentially to HEV in peripheral lymph nodes and tonsils, B lymphocytes show preferential binding to HEV in GALT. Moreover, by analyzing the binding characteristics of T4+ and T8+ T cell populations, it was found that T8+ cells adhere preferentially to HEV in GALT and mesenteric lymph nodes and tonsil, and that T4+ cells bind slightly better to HEV in peripheral lymph nodes. The above findings indicate that organ--specific lymphocyte-endothelial cell recognition mechanisms exist also in humans, and suggest that these mechanisms play an important role in normal and pathologic lymphocyte traffic.     

Signaling defects in T lymphocytes of patients with malignancy

In patients with cancer, alterations in the expression of T-cell receptor-associated molecules in tumor-infiltrating lymphocytes (TIL) as well as in circulating lymphocytes have been reported. By quantitative flow cytometry analysis, decreased or absent expression of the ζ chain in CD4⁺ or CD8⁺ T cells as well as in natural killer (NK) cells was demonstrated in patients with malignancies. Changes in the expression of ζ are biologically significant, because the absence or low expression of this signaling molecule in TIL of patients with stage III or IV head and neck cancer predicts a significantly shorter 5-year survival than that of patients with normal ζ expression in TIL. Preliminary evidence indicates that expression of ζ in TIL may not only influence survival but also predicts a favorable response to biologic therapies. Patients with cancer also show significantly greater spontaneous ex vivo apoptosis in peripheral blood mononuclear cells (PBMC) compared to normal controls, as measured by a terminal deoxynucleotide transferase-mediated dUTP nick end labeling (TUNEL) assay. While no correlation could be established between the proportions of cells with low ζ chain expression and those that spontaneously apoptose ex vivo, the ζ chain has been shown to be cleaved by caspases in T cells coincubated with tumor cells or with T cells exposed to CH-11 antibody, which induces apoptosis upon crosslinking Fas on the cell surface. The results suggest that low/absent ζ chain expression and lymphocyte apoptosis may be manifestations of negative effects of the tumor on the host immune system. Received: 20 March 1999 / Accepted: 3 May 1999