SEARCH · PubMed Health

Results for “CD8-Positive T-Lymphocytes”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources

PubMed1991

CD4-positive T lymphocytes are required for the generation of the primary but not the secondary CD8-positive cytolytic T lymphocyte response to herpes simplex virus in C57BL/6 mice.

To understand the cellular basis for recovery from HSV infection, it is critical to identify functional interactions between HSV-specific T lymphocyte subpopulations involved in the generation of the optimal response. To this end, the requirement for CD4+ (L3T4+) T lymphocytes in the development of the primary and secondary CD8+ (Lyt-2+) cytolytic T lymphocyte (CTL) response following HSV infection in C57BL/6 mice was investigated. It was found that chronic depletion of CD4+ cells in vivo by treatment with the mAb GK1.5, which resulted in greater than 95% depletion of peripheral CD4+ T lymphocytes in treated animals, caused a profound decrease in the levels of cytolytic activity obtained during the primary response in the draining popliteal lymph nodes of mice responding to infection in the hind footpads. However, treatment did not affect the levels of in vivo secondary CTL activity in the popliteal lymph nodes, nor the in vitro secondary response in the spleen. The decreased CTL activity observed during the primary response was not due to an inability to prime HSV-specific CTL precursors (CTLp), as full cytolytic activity was obtained following culture of lymphocytes in the presence of exogenous IL-2 and antigen, and the response could be reconstituted by treatment with recombinant IL-2 in vivo. Analysis of the secondary CTL response in the spleen indicated that CD4+ cells were not required for either the generation or maintenance of this aspect of the response. However, blockade of IL-2 utilization by CTL using anti-IL-2R antibodies indicated that this lymphokine was absolutely essential for secondary CTL expansion in vitro. Finally, mice that had been infected 12 months previously exhibited a decreased ability to generate secondary HSV-specific CTL in vitro following CD4-depletion in vivo. Taken together, these results suggest two distinct stages of CTL development during the response: an early primary stage dependent upon the presence of CD4+ cells, and a later, CD4-independent stage operative during the secondary response, which decays with time postinfection.

Animals↗

PubMed1992

The decrease of CD8-positive lymphocytes in Alzheimer's disease.

The aim of this study was to analyze the possible association of the changes in systemic immunity in the neurodegenerative diseases and in brain atrophy per se. Therefore we enumerated the numbers and proportions of the CD3-, CD4- and CD8-positive cells and B-lymphocytes in peripheral blood of 136 patients with various neurodegenerative disorders of the brain and 58 healthy age-matched controls. The selective decrease of the CD8-positive lymphocytes was demonstrated in the patients with Alzheimer's disease. In contrast, in the patients with brain atrophy of unknown origin and in the patients with vascular dementia the number of the CD8-positive cells tended to increase. The results suggest that brain degenerative changes are associated with changes in the systemic immunity and the changes are linked with the underlying disorder more than brain degeneration per se.

Adult↗

PubMed1991

Patients with HIV infection have a reduced proportion of lymphocytes expressing the IL2 receptor p55 chain (TAC, CD25).

Using a high-sensitivity immunofluorescence procedure, a proportion of blood lymphocytes can be shown to express the p55 chain of the IL-2 receptor (CD25, TAC) without in vitro stimulation. In this study, we measured the proportion of peripheral blood lymphocytes expressing CD25 in patients with a diagnosis of HIV infection and compared the results with cells from controls. The mean value for HIV-positive samples was 15%, while controls gave a mean value of 31%. The difference between the groups was highly significant (P less than 0.001, Mann-Whitney U test). When expression of CD25 was examined separately in CD4-positive and CD8-positive T cells and in B cells, there was a wider spread of values in the HIV group compared with controls, but no systematic difference. In the patient group studied (110 samples from 53 patients) there was a weak correlation between CD25 and CD4 expression (correlation coefficient r = 0.21, P less than 0.02), but there were patients with low CD25 and high CD4 as well as patients with high CD25 and low CD4, suggesting that CD25 can vary independently of changes in CD4 lymphocytes. Although the majority of very low values of CD25 (less than 10%) were found in patients with stage IV disease, such low values were also common in Stage II disease.

Adult↗

PubMed1992

Immunological modulation of lymphocyte subpopulation in cervical cancer tissue by sizofiran and OK-432.

The intimate correlation between marked lymphocyte infiltration in the cancer tissue and the superior clinical prognosis has been reported in human cancers. Sizofiran (SPG), a polysaccharide consisting of beta-1,3-D-glucopyranosyl linkage with beta-1,6-D-glucopyranosyl branches, or OK-432, a heat- and penicillin-treated, lyophilized preparation of the Su strain of Streptococcus pyogenes of human origin, was administered intratumorally to nine patients with advanced uterine cervical carcinoma before radical hysterectomy to assess their immunological modulating properties to tumor-infiltrating lymphocyte subpopulations immunohistochemically. The degree of infiltration of CD3- and CD5-positive cells increased moderately or markedly in the stroma surrounding the lesion in both SPG group and OK-432 group, as well as that of CD4- and CD8-positive cells, from that before administration. The density of infiltration of CD3-positive, CD4-positive, and CD8-positive cells in the lesion increased slightly or moderately in both groups after administration. As for CD16-positive cell infiltration, both SPG and OK-432 increased its degree in the stroma lining the lesion while SPG alone augmented its degree in the lesion. This augmentation of lymphocyte infiltration in situ induced by intratumoral administration of SPG and OK-432 is expected to lead to a favorable prognosis of patients with cervical cancer.

Adult↗

PubMed1992

Development of the B- and T-cell compartments in porcine lymphoid organs from birth to adult life: an immunohistological approach.

Using immunohistological techniques, we studied the development over time of B- and T-cell compartments in the lymphoid organs of specific-pathogen-free pigs. Tissue samples were collected at various time-points, starting 2 days before the pigs were born until the pigs were 10 months old. The samples were collected from the spleen, thymus, peripheral lymph node, mesenteric lymph node, duodenum, jejunum, ileum, jejunal Peyer's patch and ileal Peyer's patch. Monoclonal antibodies specific to B- and T-cells were used to identify where the following cells were localized: IgM-B cells (cells positive to surface immunoglobulin), IgM-, IgG- and IgA-containing cells (cells positive to cytoplasmic immunoglobulin), and CD2-, CD4- and CD8-positive cells. The development of the B- and T-cell subpopulations in each organ was analysed. Two days before birth, most organs contained quantities of IgM-B cells. The spleen, lymph nodes, Peyer's patches and, notably, the thymus, contained some immunoglobulin-containing cells (Ig-CC); this finding indicates that pigs have cells that secrete immunoglobulins before birth. Just after birth, the incidence of Ig-CC increased in most organs; first IgM-CC increased, then either IgG- or IgA-CC increased, depending on the organ. T-cell development was observed clearly in spleen and in the lamina propria of the small intestine, in contrast to other organs, in which the T-cell compartments containing various T-cell subpopulations were well developed before birth. Comparison of the incidence of CD4+ and CD8+ cells showed that the CD4:CD8 ratio of these cells in the spleen, lymph nodes, Peyer's patches and small intestine is low, especially in adult pigs, compared with the CD4:CD8 ratio in other species. Weaning had little influence on the incidence of B- and T-cells in lymphoid organs. This study is the first immunohistological survey to describe the development of the major B- and T-cell subpopulations in various lymphoid organs of pigs, and it should be useful for future immunopathological and comparative immunological studies in pigs.

Aging↗

PubMed1992

Pathogenesis of central nervous system lesions in visna: cell-mediated immunity and lymphocyte subsets in blood, brain and cerebrospinal fluid.

There are several indications that central nervous system (CNS) lesions in visna are immune-mediated and that cell-mediated immunity (CMI) may be of importance in the initiation of the lesions. To study the role of CMI in the pathogenesis of CNS lesions, five sheep were infected by intracerebral inoculation with visna virus and observed for 1 year. The following parameters were monitored at regular intervals: (1) neutralizing and ELISA antibodies; (2) visna virus-specific stimulation of lymphocytes from peripheral blood; (3) lymphocyte subpopulations in peripheral blood, cerebrospinal fluid (CSF) and brain at sacrifice. The CNS lesions were graded and compared with other parameters. The time course and titers of antibodies did not correlate with the severity of CNS lesions whereas the CMI did, indicating that CMI may play an important role in lesion development. The correlation of the number of CD8-positive cells in the CSF with the severity of lesions and the reversed ratio of CD4/CD8-positive cells in the diffusely infiltrated neuroparenchyma indicates that the CD8-positive T lymphocyte may be an important effector cell in the induction of CNS lesions.

Animals↗

PubMed1992

Interferon-gamma-mediated suppression of erythroid progenitor growth by a HLA-DR- and CD4-positive subset of T lymphocytes in acute myeloid leukemia.

In this study, we examined the effects of peripheral blood T lymphocytes from patients with acute myeloid leukemia (AML) on marrow-derived erythroid progenitors (BFU-DE and CFU-DE) growth in an in vivo culture by using the plasma clot diffusion chamber (DC) technique. The application of double-compartment chambers (each compartment separated by a membrane filter) makes the investigations of humoral effects of T lymphocytes upon marrow erythroid progenitors proliferation possible. T lymphocytes of AML-patients in the absence of a statistically significant number of monocytes suppressed the growth of BFU-DE and CFU-DE from T lymphocyte- and adherent cell-depleted marrows. The inhibition ability was restricted to the CD4-positive enriched fraction obtained from T cells by using the negative selection technique. In contrast, the CD8-positive enriched fraction had no effect on erythroid colony formation. Autologous and allogeneic BFU-DE and CFU-DE were similarly affected by the CD4-positive T cells. Treatment of T cells with monoclonal antibodies against HLA-DR before cocultures, completely abrogated the suppression of BFU-DE and CFU-DE-derived colony formation. Suppressive activity detected in the CD4-positive T cells was also totally abolished by treatment with anti-interferon-gamma antibodies; whereas the inhibition was retained after 30 Gy radiation. Under these experimental conditions, resting T lymphocytes from healthy subjects did not affect the erythroid colony formation. Our data show that in AML-patients, a circulating HLA-DR-positive, less radiosensitive subset within the CD4-positive T cells is capable of inducing an interferon-gamma-mediated suppression of erythropoiesis, at least in DC culture.

CD4-Positive T-Lymphocytes↗

PubMed1991

HLA class I-restricted human cytotoxic T cells recognize endogenously synthesized hepatitis B virus nucleocapsid antigen.

Knowledge of the immune effector mechanisms responsible for clearance of hepatitis B virus (HBV)-infected cells has been severely limited by the absence of reproducible systems to selectively expand and to characterize HBV-specific cytotoxic T lymphocytes (CTLs) in the peripheral blood of patients with viral hepatitis. By using a strategy involving sequential stimulation with HBV nucleocapsid synthetic peptides followed by autologous, or HLA class I-matched, HBV nucleocapsid transfectants, we now report the existence of CTLs able to lyse target cells that express endogenously synthesized HBV nucleocapsid antigen in the peripheral blood of patients with acute viral hepatitis B. The CTL response is HLA-A2 restricted, mediated by CD8-positive T cells, and specific for a single epitope, located between amino acid residues 11 and 27 of HBV core protein; these residues are shared with the secretable precore-derived hepatitis B e antigen. Equivalent lysis of target cells that express each of these proteins suggests that their intracellular trafficking pathways may intersect. The current report provides definitive evidence that HLA class I-restricted, CD8-positive CTLs that recognize endogenously synthesized HBV nucleocapsid antigen are induced during acute HBV infection in humans and establishes a strategy that should permit a detailed analysis of the role played by HBV-specific CTLs in the immunopathogenesis of viral hepatitis.

B-Lymphocytes↗

PubMed1992

Herpes simplex virus-1-specific human cytotoxic T lymphocytes are induced in vitro by autologous virus-infected mononuclear cells.

A new technique for in vitro activation of cytotoxic T lymphocytes (CTLs) specific for herpes simplex virus type 1 (HSV-1) is described. Autologous phytohemagglutinin (PHA)-activated, HSV-1-infected peripheral blood mononuclear cells (PBMC) were used, after fixation with 1% paraformaldehyde, to activate virus-specific CTLs in short-term cultures. The same unfixed PBMC were used as target cells in the cytotoxicity assay. By using this technique high levels of HSV-1-specific cytotoxic activity (50.06 +/- 16.76% at 30:1 effector:target ratio) were repeatedly obtained in 24 experiments using PBMC from 16 HSV-1 antibody-positive healthy donors, while no cytotoxic activity was observed using PBMC from 3 HSV-1 antibody-negative donors. HSV-1-induced CTLs were shown to be virus-specific as they did not lyse autologous, PHA-activated PBMC infected with influenza A virus or autologous Epstein-Barr virus (EBV) lymphoblastoid cell line (LCL), while they were able to lyse both HSV-1-infected, autologous PHA-activated PBMC and EBV-LCL. HSV-1-specific cytotoxicity was mediated by T lymphocytes, since depletion of CD3-positive cells from the effector population completely removed the killing of HSV-1-infected target cells. CD8-positive CTLs were primarily involved in the killing of HSV-1-infected targets since depletion of CD8-positive cells caused a strong reduction of virus-specific cytotoxic activity while elimination of CD4-positive lymphocytes increased killing capacity. Finally, this technique has proven to be highly reproducible, easy to perform, and thus suitable for clinical investigations.

Cell Line↗

PubMed1990

HLA-Bw54-DR4-DRw53-DQw4 haplotype controls nonresponsiveness to hepatitis-B surface antigen via CD8-positive suppressor T cells.

We have previously reported that in nonresponders to hepatitis-B (HB) vaccine there was an HLA-linked immune suppression gene for hepatitis-B surface antigen (Is-HBsAg) controlling the nonresponsiveness to HBsAg, through HBsAg-specific suppressor T cells, and that the Is-HBsAg was in strong linkage disequilibrium with the HLA-Bw54-DR4-DRw53 haplotype (1). We have now done the HLA typing on an additional 6 nonresponders, and using the system of T-cell proliferative response to HBsAg we found that the Is-HBsAg controlled the nonresponsiveness to HBsAg through HBsAg-specific suppressor T cells in nonresponders to HB vaccine who have HLA-Bw54-DR4-DRw53-DQw4 haplotype. T- and B-cell recognition of HB vaccines might play an important role at 3 to 5 weeks after the last immunization. Use of an anti-HLA monoclonal antibody has shown that the HLA-DR molecule plays an important role in helper T-cell proliferation in nonresponders, although the role of HLA-DQ molecule in nonresponders was unclear.

Antibodies, Monoclonal↗

PubMed1991

Expression of CD31 epitopes on human lymphocytes: CD31 monoclonal antibodies differentiate between naive (CD45RA+) and memory (CD45RA-) CD4-positive T cells.

The CD31 antigen, a member of the immunoglobulin superfamily with a possible cell adhesion function, is expressed on approximately 50% of peripheral blood lymphoid cells at relatively low intensity (10-20% of the level on monocytes). In the accompanying paper we showed that a mAb, 5A2.G5, which identifies a glycosylation-dependent epitope of the CD31 antigen, bound to fewer lymphocytes than two other CD31 mAb, B2B1 and 2BD4, although the 3 antibodies bound equally well to monocytes. We have now analyzed the pattern of expression of epitopes of the CD31 antigen on lymphoid cell subpopulations using two-color immunofluorescence and flow cytometry. Large granular lymphocytes (CD16+), CD8-positive T cells and B cells (SMIg+) were mostly CD31-positive as indicated by the binding of mAb B2B1 and 2BD4. Single populations displaying some overlap with the negative control were obtained in each case. In contrast, CD4-positive T cells fell into two discrete populations with respect to CD31 antigen expression. mAb 5A2.G5 displayed weaker binding to all lymphoid cell types, indicating that the pattern of glycosylation of the CD31 antigen differs between lymphocytes (of all types) and cells of the myeloid lineages. The heterogeneity of CD31 antigen expression by CD4-positive cells was further examined by dual-labelling of purified CD4 cells with mAb B2B1 and CD45RA or CD29 mAb which identify naive and memory T cells respectively. The CD31 antigen was found to be preferentially expressed by the CD45RA-positive, naive cell population.

Antibodies, Monoclonal↗

PubMed1990

Diversity of Francisella tularensis antigens recognized by human T lymphocytes.

The Francisella tularensis T-lymphocyte antigens, which may have a role in protection against tularemia, were investigated with vaccine-immunized subjects. Preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was used to fractionate the bacterial envelope preparation. The 23 fractions obtained represented membrane proteins of different apparent molecular masses ranging from 10 to 150 kilodaltons. Different fractions contained one to four separate protein bands stained with Coomassie blue. The lymphocyte blast transformation responses of five tularemia vaccine-immunized and three nonimmunized subjects were tested against bacterial material eluted out of SDS-PAGE fractions. Every fraction stimulated lymphocytes from at least one of the subjects. No clearly immunodominant or inhibitory antigens were detected among the envelope fractions. Expression of the HLA-DR antigen at the surface of CD4- and CD8-positive lymphocytes was also studied as a measure of cell activation. The numbers of CD4+ DR+ cells varied directly with the lymphocyte proliferation profiles, and very few CD8+ cells were found in the preparations stimulated with the different fractions. The diversity of the antigens recognized by immune T lymphocytes was confirmed by using F. tularensis-specific T-lymphocyte clones obtained from vaccinated subjects. Most of the 36 T-lymphocyte clones tested were stimulated by one SDS-PAGE fraction only.

Antigens, Bacterial↗

PubMed1992

Role and specificity of T-cell subsets in spontaneous recovery from Friend virus-induced leukemia in mice.

Spontaneous recovery from Friend virus complex-induced leukemic splenomegaly in H-2Db/b mice correlated with the appearance of Friend virus complex-specific cytotoxic T lymphocytes (CTL) detectable directly in spleen cell populations. By testing CTL on target cells containing expression vectors encoding individual retroviral structural proteins, the main viral protein recognized was shown to be the Friend murine leukemia helper virus envelope glycoprotein. In vivo depletion of CD8-positive T cells drastically reduced the incidence of recovery, providing direct evidence for the role of CD8-positive CTL in the spontaneous recovery process. In vivo depletion of CD4-positive cells had little effect on the early stages of recovery but did cause a marked reduction in the final incidence of recovery at 60 to 90 days. Thus, CD8-positive cells were required for the initiation of the recovery process, whereas CD4-positive cells appeared to be required for maintenance of the recovered status.

Animals↗

PubMed1990

Effect of glycyrrhizin on pain and HLA-DR antigen expression on CD8-positive cells in peripheral blood of herpes zoster patients in comparison with other antiviral agents.

Glycyrrhizin (GL) is a saponin widely used as an anti-inflammatory agent. Pain intensity and HLA-DR antigen expression on CD8+ cells were assessed during and after treatment with GL. Other agents such as acyclovir, gamma-globulin and interferon beta were also administered for comparison. Pain resolved most rapidly among those treated with acyclovir followed by those treated with GL. Pain resolution correlated with the regression of HLA-DR+ in CD8+ subpopulations in peripheral blood. GL is suggested to be an alternative or additive antiviral agent to herpes zoster.

Acyclovir↗

PubMed1992

Distribution of lymphoid cells in tonsillar compartments in relation to infection and age. A quantitative study using image analysis.

The distribution of lymphoid cells in the mantle zone, germinal center, interfollicular area, and subepithelial area of the tonsil was evaluated quantitatively by image analysis in 66 subjects aged 3 to 66 years. The number of Ig-positive cells in the tonsil decreased with advancing years in all compartments. This inverse correlation to age was statistically significant for IgD-, IgM-, and IgG-positive cells. For T-cells, overall change of each T-cell subset with age was smaller than those of Ig-positive cells. An age-related marked decline was seen for CD4-positive cells only in the subepithelial area and for CD8-positive cells only in the interfollicular area. Ki-67-positive cells, cells undergoing active division, were mainly found in the germinal centers and also diminished with advancing years. Patients with frequent episodes of tonsillitis demonstrated a significant increase of IgD-positive cells and IgG-positive cells in interfollicular and subepithelial compartments and a decrease of CD4-positive T-cells in the germinal centers and subepithelial areas. These results suggest that the tonsillar involution with age is immunologically associated in all compartments with the decrease of Ig-positive cells and Ki-67-positive activated cells resulting in a relative increase of T-cell subsets. The method of image analysis provides a novel and unique approach for quantitative immunohistological study of the tonsil.

Adolescent↗

PubMed1991

Analysis of the mechanism of graft-versus-host-like disease in B6 mice with transferred B6-lpr spleen cells.

Irradiated C57BL/6(B6) mice, when they were injected with spleen cells of C57BL/6J-lpr/lpr(B6-lpr) mice, developed splenomegaly at 2 weeks post-transfer, but afterward displaced by GVH-like disease. At 2 weeks the enlarged spleen in the chimeric mice, designated as [B6-lpr----B6] chimera, contained about 70% of the total cell population as CD8-positive T cells. Spleen cells from [B6-lpr----B6] chimeras were unresponsive to Con A and LPS stimulation and suppressed the mitogenic response of B6, B6-lpr, and C3H spleen cells to Con A. However, they had no cytotoxic activity towards Con A blasts of B6 and B6-lpr spleen cells. The suppressor activity found in the [B6-lpr----B6] spleen cells was removed by pretreatment of them with anti-Thy-1.2 or anti-CD8(Lyt2.2) plus complement. The present experiment showed that enormous proliferation of CD8-positive suppressor T cells was induced in the [B6-lpr----B6] chimeras. These cells were probably responsible for the GVH-like lymphoid atrophy observed in these [B6-lpr----B6] chimeras.

Animals↗

PubMed1992

Intrahepatic lymphocyte subpopulations and HLA class I antigen expression by hepatocytes in chronic hepatitis C.

The lymphocyte subpopulations in the peripheral blood and liver were studied in 17 patients with chronic active hepatitis type C (CAH C) by immunoenzymatic and immunofluorescence techniques, using mono-specific T cell antibodies and other reagents. The peripheral blood subsets showed no significant differences between the patients with CAH C and normal controls. In the liver, CD8-positive cells were predominant over CD4- and Leu 7-positive cells. Leu 7-, CD4-, and CD11-positive lymphocytes were all few in number. HLA class I antigen was expressed diffusely on the cell surfaces of the hepatocytes. Serum levels of soluble interleukin 2 receptor (sIL2R) in the CAH C patients were significantly higher than in normal controls (p less than 0.01). In CAH C, sIL2R levels were higher during exacerbations than during remissions (p less than 0.01). These results suggest that cytotoxic T cells (CD8- positive, CD4-negative, and CD11-negative) may play an important role in the pathogenesis of hepatocyte injury in patients with CAH C.

Antibodies, Monoclonal↗

PubMed1990

The HML-1 antigen of intestinal lymphocytes is an activation antigen.

The Ag recognized by the mAb HML-1 is expressed on more than 90% of human intestinal intraepithelial lymphocytes, whereas in other lymphoid tissues it is rarely or not expressed. In the present study, we have investigated the percentage of HML-1-positive cells in the human intestinal lamina propria and the coexpression of HML-1 with different T cell subset markers. In addition, we studied the inducibility of HML-1 on PBL which normally are HML-1-negative. Flow cytometric analysis of isolated intestinal lamina propria lymphocytes (LPL) showed that about 40% of the cells expressed HML-1, the majority belonging to the CD8-positive subpopulation. Virtually all LPL expressed CD45RO, whereas the percentage of CD29-positive cells was only about 50%, similar to PBL. There were only few cells expressing CD45RA or Leu-8 in the lamina propria. HML-1-positive cells were almost exclusively CD45RA-negative, but were found in both the CD29-positive and the CD29-negative subpopulation of LPL. In vitro stimulation of PBL showed that the expression of HML-1 was inducible on T cells by mitogens, phorbolester, Ag, and rIL-2. Expression of HML-1 was induced with a different time course and with differences in the response to the investigated stimuli compared with CD25. Activated HML-1-positive PBL were also predominantly CD45RA-negative. The findings show that HML-1 is an Ag, which is expressed in vivo on a specific subset of previously activated T cells in the unique environment of the intestinal mucosa, and which can be induced in vitro by different activation signals on PBL.

Antibodies, Monoclonal↗