An activated CD8+ lymphocyte appears in lymph nodes of rhesus monkeys early after infection with simian immunodeficiency virus

Although alterations in T lymphocyte subset distribution and function in the peripheral blood of HIV-infected humans are well defined, the extent to which these reflect changes in other lymphoid compartments is unclear. We have characterized the coincident changes in PBL and lymph nodes (LN)1 after simian immunodeficiency virus of macaques (SIVmac) infection of rhesus monkeys. Whereas no consistent change in CD8+ PBL was noted during the first 60 d after infection, CD8+ lymphocytes increased significantly in number in LN. These CD8+ LN lymphocytes exhibited an increased expression of MHC class II and a decreased expression of leukocyte adhesion molecule-1, suggesting that they were activated, but interestingly did not express CD25 (IL-2 receptor). Moreover, there was no evidence that these CD8+ LN cells were proliferating, suggesting that they had migrated to the LN. These changes in the LN CD8+ lymphocyte population preceded any detectable change in the light microscopic appearance of the LN. When SIVmac-specific effector T cell responses were assessed, the magnitude of virus-specific effector activity was nearly identical in the PBL and LN of each monkey studied. However, the presence of SIVmac-specific effector cells in the LN did not correlate with the presence of CD8+, MHC class II+ cells. These findings suggest that this numerically important CD8+ lymphocyte subpopulation may serve a regulatory function.

Nucleocapsid or spike protein-specific CD4+ T lymphocytes protect against coronavirus-induced encephalomyelitis in the absence of CD8+ T cells

To investigate the antiviral CD4+ T cell response in coronavirus MHV-JHM-induced encephalomyelitis, spleen and thymic lymphocytes from diseased rats were stimulated in culture with virus Ag, expanded and tested for their specificity to viral proteins and nucleocapsid (N) and spike (S) proteins that had been expressed in bacteria. A strong T cell response specific for N was measurable during acute disease, whereas S-specific T cells were only detectable in rats with a later onset of disease. CD4+ T cell lines with specificity for virus and either N or S protein were established and their influence on the course of a mouse hepatitis virus-JHM infection was investigated. All lines were of the CD4+ phenotype. Both N and S protein-specific CD4+ T cells conferred protection to infected Lewis rats and reduced the amount of infectious virus in the central nervous system. After transfer of CD4+ T cells and challenge with virus, an increase in the antiviral IgM response occurred, but neutralizing antibodies were not detectable during the period of virus clearance. Previous CD8+ cell depletion did not abrogate protection mediated by CD4+ T cell line transfer.

Characterization of human T cells reactive with the Mycoplasma arthritidis-derived superantigen (MAM): generation of a monoclonal antibody against V beta 17, the T cell receptor gene product expressed by a large fraction of MAM-reactive human T cells

While all known microbial superantigens are mitogenic for human peripheral blood lymphocytes (PBL), the functional response induced by Mycoplasma arthritidis-derived superantigen (MAM) is unique in that MAM stimulation of PBL consistently results in T cell-dependent B cell activation characterized by polyclonal IgM and IgG production. These immunostimulatory effects of MAM on the humoral arm of the human immune system warranted a more precise characterization of MAM-reactive human T cells. Using an uncloned MAM reactive human T cell line as immunogen, we have generated a monoclonal antibody (mAb) (termed C1) specific for the T cell receptor V beta gene expressed by the major fraction of MAM-reactive human T cells, V beta 17. In addition, a V beta 17- MAM-reactive T cell population exists, assessed by MAM, induced T cell proliferation and cytotoxic T cell activity. mAb C1 will be useful in characterizing the functional properties of V beta 17+ T cells and their potential role in autoimmune disease.

Wild type and tailless CD8 display similar interaction with microfilaments during capping

We examined the influence of the intracytoplasmic region of CD8 alpha on capping and interaction with microfilaments. We used cell clones obtained by transfecting a CD4+ T-cell hybridoma with (a) T-cell receptor (TCR) alpha and beta chains from a cytolytic clone and (b) CD8 alpha genes that were either native or modified by extensive deletion of the intracytoplasmic region or replacement of the transmembrane and intracytoplasmic domains with those of a class I major histocompatibility complex gene (Letourneur et al. (1990). Proc. natn. Acad. Sci. U.S.A. 87, 2339–2343). Different cell surface structures were cross-linked with anti-T-cell receptor, anti-CD8 or anti-class I monoclonal antibodies and anti-immunoglobulin (Fab')2. Double labeling and quantitative image analysis were combined to monitor fluorescence anisotropy and correlation between different markers. Microfilaments displayed maximal polarization within two minutes. The correlation between these structures and surface markers was then maximal and started decreasing, whereas the redistribution of surface markers remained stable or continued. Furthermore, wild type and altered CD8 alpha exhibited similar ability to be capped and to induce co-capping of TCR and MHC (major histocompatibility complex) class I: the fraction of cell surface label redistributed into a localized cap ranged between 40% and 80%. Finally, cytochalasin D dramatically decreased CD8 capping in all tested clones. It is concluded that the transmembrane and/or intracellular domains of CD8 molecules are able to drive the extensive redistributions of membrane structures and cytoskeletal elements that are triggered by CD8 cross-linking.

Detection of hyperreactive T cells in multiple myeloma by multivalent cross-linking of the CD3/TCR complex

Cellular immunity was investigated in 43 patients with multiple myeloma (MM) by assessing 3HTdR uptake induced by monocyte-dependent [CD3 monoclonal antibodies (MoAbs), phytohemagglutinin (PHA)] and monocyte-independent (CD2 MoAbs, ionomycin + phorbolester) stimulations. The former were evaluated in peripheral blood mononuclear cells (PBMNC) and purified T cells; the latter were evaluated in purified T-cell preparations only. MM showed significantly lower PBMNC responses to PHA (P less than .001), soluble OKT3 (CD3) (P = .01), and immobilized OKT3 MoAbs (P = .01). On purification of T cells, MM responses were still defective to soluble T11(2) + T11(3) (CD2) MoAbs (P = .004), phorbol myristate acetate (PMA) plus ionomycin (P less than .001), but significantly higher to plastic-immobilized OKT3 (P = .004). In some MM, 3HTdR uptake, interleukin-2 (IL-2) receptor (CD25) expression, and IL-2 production were as high on stimulation with plastic-immobilized OKT3 as that observed in normal subjects under optimal conditions (ie, plastic-immobilized OKT3 plus accessory signals). CD3 hyperreactivity correlated with the number of CD8+ HLA-DR+ cells in MM T-cell preparations. MM patients with more than 10% CD8+ HLA-DR+ cells had significantly higher responses to immobilized OKT3 (P less than .001), but lower responses to T11(2) plus T11(3) (P = .01), and PMA plus ionomycin (P = .03) than patients with less than 10% CD8+ HLA-DR+ cells. Phenotyping of CD45RA (naive) and CD45R0 (memory) expressions in resting MM T cells showed a lower ratio of CD45RA to CD45R0 in both CD4 (P less than .05) and CD8 (P less than .001) subpopulations. These data indicate that (a) some MM T cells require significantly fewer accessory signals (if any) to express the IL-2 receptor fully, secrete IL-2, and proliferate on multivalent cross-linking of the CD3/TCR complex; and (b) this peculiar state of activation is associated with high HLA-DR expression in CD8+ lymphocytes.

Differential T cell hyporesponsiveness induced by in vivo administration of intact or F(ab')2 fragments of anti-CD3 monoclonal antibody. F(ab')2 fragments induce a selective T helper dysfunction

Induction of peripheral T cell anergy associated with stimulation through the TCR complex in vivo has been described in mice using chemically modified APC, staphylococcal enterotoxin B, and intact anti-CD3 mAb. In the latter two models, T cell proliferation, IL-2R expression, and lymphokine production have been demonstrated before subsequent induction of hyporesponsiveness, whereas in the former model, these events have not been observed. To further investigate the relationship between mitogenicity and induction of peripheral hyporesponsiveness, mice were treated with either mitogenic intact anti-CD3 mAb or nonmitogenic F(ab')2 fragments of anti-CD3 mAb. T cells from F(ab')2-treated mice demonstrated a selective decrease in helper functions, with minimal effect on CTL function. Specifically, a marked reduction in ability of Th cells to secrete IL-2 when challenged in vitro with mitogen or alloantigen was observed, which persisted for at least 2 mo after mAb administration and which was independent of T cell depletion. Proliferative function was decreased in CD4+ T cells and could not be fully restored with addition of exogenous IL-2. A helper defect was also evident in vivo, in that F(ab')2-treated mice were deficient in their ability to reject MHC-disparate skin grafts, and in vivo administration of IL-2 reconstituted their ability to reject skin grafts normally. In contrast, T cells from mice treated with intact mAb demonstrated a significant decrease in both CTL and helper functions. A long term reduction in TCR expression on CD4+ cells from F(ab')2-treated mice, and on both CD4+ and CD8+ cells from intact mAb-treated mice was observed. These findings demonstrate that peripheral T cell hyporesponsiveness can be induced in vivo by binding an identical epitope on the TCR complex in the presence or absence of initial proliferation, lymphokine secretion, or IL-2R expression, and that binding to the same epitope can result in varying long term effects on T cell function.

Immune function parameters at diagnosis in patients with myelodysplastic syndromes: correlation with the FAB classification and prognosis

We determined nine immune function parameters at diagnosis in patients with myelodysplastic syndromes (MDS) and correlated the results with the FAB classification and prognosis by univariate and multivariate analyses. Patients with refractory anaemia (RA) and refractory anaemia with ring sideroblasts (RAS) tended to have a higher CD4/CD8 ratio and a lower amount of gamma-globulins and soluble interleukin-2 receptors in serum in comparison to those suffering from the other three subgroups of MDS. FAB classification, neutrophil and CD8+ T-cell number had the best discriminatory capacity for predicting survival less than 1 year, and FAB classification, neutrophil number and serum TNF levels were predictors for conversion to acute leukaemia. The frequent occurrence of infections, on the other hand, could be better predicted by the absolute numbers of neutrophils and CD4+ cells and by the skin test score.

Phenotype of intramyocardial leukocytic infiltrates in acquired immunodeficiency syndrome (AIDS): a postmortem immunohistochemical study in 34 consecutive cases

In 34 hearts, obtained at autopsy in consecutive AIDS cases, leukocytic phenotype and presence of viral antigens were investigated in paraffin-embedded (34 cases) and frozen myocardial sections (10 cases) by different monoclonal antibodies. The total frequency of focal lymphocytic infiltrates with and without myocell necrosis was 26.4 and 32.3%, respectively. In six control cases (HIV-negative i.v. drug abusers dying from acute fulminating hepatitis), these infiltrates were absent. In AIDS patients, the number of infiltrative foci per section, their wall distribution (subendocardial, middle layer, subepicardial), number of leukocytes per focus, and cell phenotype (prevalence of CD8+ suppressor/cytotoxic T-lymphocytes with CD4/CD8 ratio of 0.6 +/- 0.09 SE, absence of B-cells and granulocytes) were similar in cases with and without myocell necrosis. Significant differences were not observed between homosexual and i.v. drug abuser patients. In inflammatory foci associated with myocell necrosis CD45+/CD68+ monocytes prevailed, as a possible manifestation of nonspecific reparative process. In addition, in both AIDS patients and HIV-negative drug abusers, a population of CD68+ dendritic monocytes (histiocytes) characterized by a restricted CD45 expression (PanLeu-/9.4+) was found dispersed in the interstitium, with a significant higher frequency in the subendocardial layer. Histologic evidences of myocardial virus infections were not observed. Cytomegalovirus (CMV) antigens, however, were found in frozen sections of five of the six cases with lymphocytic infiltrates, supporting the view that this virus can be one of the possible causes of myocarditis in AIDS. Moreover, in two of these CMV-positive cases, a concomitant expression of HIV1 antigens in isolated intramyocardial leukocytes was also observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Interleukin-2 receptor in peripheral blood lymphocytes of Alzheimer's disease patients

In this study, we investigated the differences in the incidence rate of human leukocyte antigen-DR (HLA-DR) and interleukin 2 receptor (IL-2R) in the peripheral blood lymphocytes of 13 women who were diagnosed clinically as having Alzheimer's disease (AD group), and 13 healthy women with no mental disorders (control group). As a result, the AD group showed a markedly higher rate of lymphocyte subsets of CD4+HLA-DR+, CD4+IL-2R+, CD8+HLA-DR+, CD8-HLA-DR+ and CD8+IL-2R+. This finding indicates a possible immune reaction occurring in the peripheral blood of AD patients. In addition, these higher rates correlate well with the changes in the immune system reported in the postmortem brains of AD patients. Our findings indicate that immunological interactions exist between the central nervous system and the peripheral blood lymphocytes of AD patients, and AD might be induced by an immune reaction occurring in the brain.

The clinical significance of serum CD8 antigen levels in adult patients with Hodgkin's disease

Increased suppressor T-cell activity has been observed in patients with Hodgkin's disease. In order to evaluate the clinical significance of soluble CD8 antigen (sCD8), which is released from CD8+ suppressor/cytotoxic T-lymphocytes, we determined sCD8 levels in the sera of 82 consecutive patients with newly diagnosed untreated Hodgkin's lymphoma who were entered into prospective trials of the German Hodgkin's Disease Study Group. sCD8 levels were significantly higher (p less than 0.01) in stage IV (781 U/ml, n = 19) than in stages I-IIIB (443 U/ml; n = 63). Patients with B-symptoms (n = 36) had slightly higher levels (611 U/ml) than patients without (n = 46) systemic symptoms (447 U/ml; p = 0.08). In 77 patients evaluable for response, the complete remission (CR) rate of patients with sCD8 less than 750 U/ml was higher (54/60 or 90%) than that of patients with sCD8 greater than 750 U/ml 11/17 or 65%; p = 0.01). The time to treatment failure was significantly longer in patients with sCD8 less than 750 U/ml (p = 0.008), even among the group with stages IIIB/IV only (p = 0.04). Our data suggest that the pretreatment levels of sCD8 in adult patients with Hodgkin's lymphoma have prognostic relevance, and that they should be determined especially in patients with advanced disease. Increased understanding of the role of sCD8 may shed light on the pathogenesis of Hodgkin's disease.

Decrease in soluble CD8 antigen levels in splenectomized patients as an index for reduced suppressor/cytotoxic cell activity

To investigate the effect of splenectomy on lymphocyte subpopulations we monitored changes in serum concentrations of soluble suppressor/cytotoxic (sCD8) and soluble helper/inducer (sCD4) antigen in 11 splenectomized patients. Indications for splenectomy were hereditary spherocytosis in 2, idiopathic thrombocytopenic purpura in 2, gastric carcinoma in 4, Hodgkin's disease in 2 and pancreatitis in 1 patient. Lymphocyte subpopulations were also analyzed by means of conventional immunophenotyping with monoclonal antibodies to CD4 and CD8. We consistently found an early postoperative drop of sCD8 and sCD4 levels within the first week after splenectomy, paralleling changes in the percentages of CD4+ and CD8+ lymphocytes. While alterations of lymphocyte subsets in the peripheral blood were completely reversible and sCD4 levels returned to preoperative values, sCD8 concentrations remained suppressed even 3 months after splenectomy. SCD8 levels at the nadir and those 3 months after splenectomy were significantly lower than preoperative values (P = 0.003, P = 0.149 respectively). Since sCD8 levels reflect suppressor/cytotoxic cell activity, we suggest that suppressor cell activity is reduced in splenectomized patients.

Influence of LTB4 on CD4-, CD8- thymocytes. Evidence that LTB4 plus IL-2 generate CD8+ suppressor thymocytes involved in tolerance to self. Effect of LTB4 and IL-2 on double negative thymocytes

Leukotriene B4 (LTB4) is produced by a large variety of cells involved in immune response and it has been demonstrated that this arachidonic acid metabolite acts as an immunomodulator. Because LTB4 and IL-2 both influence the physiology of immature cells we studied the effects of the leukotriene on double negative thymocytes. For that purpose C57 Bl/6 double negative thymocytes were treated by LTB4 plus IL-2 in the presence of either autologous or allogenic red blood cells (RBC). Then, preincubated CD4- CD8- thymocytes were cocultured with red blood cells stimulated fresh splenocytes. We observed that fresh splenocytes responding to autologous RBC were CD4+ cells and that the proliferative response of spleen lymphocytes driven by RBC was inhibited by preincubated double negative thymocytes. On the other hand a majority of double negative thymocytes overnight preincubated in vitro in the presence of both IL-2 and LTB4 give rise to CD8+ CD4- cells. Therefore we speculate that LTB4 plus IL-2 generate CD8+ suppressor thymocytes among double negative thymocytes and that these suppressive T cells are involved in tolerance to self.

Lymphocytes infiltrating ovarian malignant ascites: modulation of IL-2-induced proliferation by IL-4 and of selective increase in CD8+ T cells by TNF-alpha

Lymphocytes infiltrating ovarian malignant ascites (TALs) were propagated in vitro in the presence of low (20-50 U/ml) concentrations of recombinant interleukin-2 (rIL-2) and moderate concentrations of interleukin-4 (IL-4) and tumor necrosis factor type alpha (TNF-alpha). Neither IL-4 nor TNF-alpha alone induced proliferation of ovarian TALs, but IL-4 and TNF-alpha synergized with IL-2 in enhancing the proliferation of T cells from cultures and inducing a more specific pattern of cytotoxic responses of ovarian TAL. IL-4 enhanced the proliferation of TAL cultures in the induction phase, but did not synergize with IL-2 in enhancing the proliferation and cytotoxicity of an established autologous tumor-specific CD8+/CD4- cytotoxic T lymphocyte (CTL) line. In contrast, TNF-alpha-induced preferential expansion of CD8+ CTL in TAL cultures where CD3+/CD4+ cells were initially in excess and of an established autologous tumor-specific CD8+ CTL line. This expansion resulted in increased levels of cytoxicity against autologous tumor cells. Amplification of IL-2 growth-promoting effects and selective enrichment in T cell subsets by IL-4 and TNF-alpha may therefore be useful in cellular adoptive immunotherapy using tumor-specific T cells.

Quantitative analysis of CD6, CD4 and CD8 cell surface molecules compared to the absolute numbers of CD6+, CD4+ and CD8+ T-cells in peripheral blood in patients with HIV-infection

T lymphocyte subsets were determined on blood samples from 16 HIV-seropositive patients with manifest AIDS (CDC IV), 24 HIV-seropositive patients with lymphadenopathy syndrome (LAS, CDC III), 16 HIV-seropositive clinical healthy persons (CDC II) and 11 HIV-seronegative homosexuals as control group. Absolute numbers of T-cells (CD6+), T-helper/inducer-cells (CD4+) and T-suppressor/cytotoxic-cells (CD8+), obtained by immunofluorescence staining were compared with the absolute amount of subset specific surface molecules, obtained by a T-cell-ELISA. With both, indirect immunofluorescence technique and ELISA technique a highly significant decrease of the absolute numbers of CD4+ cells and the absolute amount of CD4 surface molecules, respectively, was found in asymptomatic HIV-infection, LAS and in manifest AIDS. In all HIV-seropositive groups the relative decrease of CD4 surface molecules was significantly greater than the decline of CD4+ cells. This phenomenon however was not seen in HIV-seronegative homosexuals. The absolute number of CD6+ cells and the amount of CD6 surface molecules were found significantly lowered in AIDS compared to HIV-seronegative homosexuals. No significant changes were found for CD8+ cell numbers and CD8 surface molecule in the progression of the HIV-infection.

Predominance of CD8 subset in id eruption of poison oak-induced dermatitis

The pathophysiology and immune mechanisms involved in the clinical syndrome of autoeczematization remain a mystery. In this study of nickel dermatitis without autoeczematization and poison oak dermatitis with autoeczematization, it was noted that the process of autoeczematization was associated with the presence of CD8+ lymphocytes within the epidermis and the expression of HLA-DR antigens on epidermal keratinocytes. It is surmised that since CD8+ clones are induced by poison oak antigen but not by nickel, the inability of nickel to induce CD8+ lymphocytes may explain why uncomplicated nickel dermatitis does not autoeczematize. Since the selective adherence of CD8+ lymphocytes to keratinocytes, probably via the expression of adhesion molecules such as ICAM-1, the generation of antigens on endothelial cells of high endothelial venules involved in lymphocyte trafficking, and the expression of HLA-DR antigens on epidermal keratinocytes are all due to the activity of interferon-8, it is deduced that this lymphokine may play a key role in id eruptions induced by contact allergens.

Predominant recognition of human T cell leukemia virus type I (HTLV-I) pX gene products by human CD8+ cytotoxic T cells directed against HTLV-I-infected cells

We established long-term cell lines of cytotoxic T lymphocytes (CTL) specific for human T cell leukemia virus type I (HTLV-I) from peripheral blood lymphocytes (PBL) of a patient with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP), an HTLV-I-carrier with Sjögren syndrome, and an asymptomatic HTLV-I-carrier, by repeated stimulation with autologous HTLV-I-infected T cells in vitro. CTL derived from the patient with HAM/TSP expressed CD8 antigen, and their function was restricted by HLA-A2. They showed cytotoxic effects predominantly against the target cells expressing HTLV-I p40tax among the autologous B cell lines infected with vaccinia recombinants containing various HTLV-I genes which served as targets. These data are consistent with the previously reported findings that fresh PBL of HAM/TSP patients contain p40tax-specific CTL activity. Furthermore, CTL derived from the patient with Sjögren syndrome without neurological involvement also demonstrated cytotoxicity predominantly to p40tax. The cytotoxicity to the target cells experimentally expressing p40tax was blocked by unlabeled HTLV-I-infected cells possessing HLA-A2. HTLV-I-specific cytotoxicity was also inhibited by unlabeled B cells bearing p40tax. Thus, HTLV-I p40tax-specific cytotoxicity is mediated by the major CTL population activated by native HTLV-I antigens in patients with HAM/TSP or Sjögren syndrome. In contrast to the CTL of these patients, CTL similarly induced from the asymptomatic HTLV-I-carrier, which were highly cytotoxic to autologous HTLV-I-infected T cells, did not show significant levels of cytotoxicity to autologous B cells expressing p40tax.(ABSTRACT TRUNCATED AT 250 WORDS)

Murine CD4-CD8- thymocytes are stimulated by interleukin-2 to proliferate in vitro in chemically defined medium

The ability of fetal and young adult CD4-CD8- thymocytes to proliferate in chemically defined (serum-free) medium in the presence and absence of IL-2 was examined. Dissociated thymocytes from day 15 and older fetal mice proliferated in vitro in the presence but not the absence of IL-2. The degree of proliferation was increased by including IL-1 with the IL-2. Inclusion of IL-1 in cultures of fetal thymocytes was associated with an increase in the number of IL-2 receptor positive cells, relative to cultures containing IL-2 alone. Although unfractionated thymocytes failed to proliferate in chemically defined medium, CD4-CD8- cells purified from thymic cell suspensions from young adult mice from several inbred strains proliferated to a limited extent in the absence of added cytokines. Proliferation was augmented 40-100 fold by inclusion of IL-2 in cultures. IL-1 stimulated some proliferation by young adult CD4-CD8- cells, but, unlike the effect of IL-1 and IL-2 on fetal thymocytes, combination of IL-1 with IL-2 did not have a notable additive effect on IL-2 induced proliferation. Proliferation stimulated by both IL-1 and IL-2 was completely abrogated by inclusion of anti-IL-2 receptor antibody in the cultures. Thymocytes from F1 progeny of inbred strains of mice proliferated to a greater extent in the absence of IL-2 than did thymocytes from either parent strain, although the response to IL-2 was not significantly different. The data demonstrate that both fetal and adult CD4-CD8- thymocytes area capable of proliferating in response to IL-2 in vitro, suggesting that, as is the case during antigen specific responses by mature T cells, IL-1 and IL-2 cooperate to stimulate T cell proliferation during development in vivo.

Regulation of mucosal responses by CD4+ T lymphocytes: effects of anti-L3T4 treatment on the gastrointestinal immune system

The role of CD4+ T cells in the gastrointestinal (GI) immune system in vivo was studied in mice selectively depleted of this subset by treatment with monoclonal anti-L3T4 (GK1.5) mAb. Treatment of young BALB/c mice with weekly injections of anti-L3T4 mAb resulted in a selective depletion of CD4+ T cells in both IgA effector (lamina propria regions of the intestine; LP) and inductive (Peyer's patch; PP) sites. However, levels of CD3+CD4-CD8+ and CD4-CD8- (double negative) T cells remained constant or increased. When sections of small intestine were assessed for the isotype of Ig-containing cells, normal mice contained predominantly IgA plasma cells with small numbers of IgM and IgG plasma cells while anti-L3T4 treatment dramatically reduced the numbers of IgA plasma cells. When numbers of IgA-producing cells were assessed by the isotype-specific ELISPOT assay, the LPL of anti-L3T4 mAb-treated mice showed an 80% reduction in the number of IgA spot-forming cells. The effect of anti-L3T4 mAb treatment on IgA inductive sites was also studied and this treatment reduced the overall size of PP as well as the germinal centers in this tissue. Although anti-L3T4 treatment depleted CD3+CD4+ T cells in PP, the relative frequency of surface IgA-positive (slgA+) B cells in this tissue did not change. These results show that repeated injection of anti-L3T4 mAb results in a CD4+ T cell deficiency in both IgA inductive (PP) and effector (LP) sites. The depletion of CD4+ T cells resulted in reductions in the numbers of mature IgA plasma cells present in the LP of gut-associated tissues, and reduced the overall size of PP including germinal centers, but did not affect the frequency of sIgA+ B cells in this IgA inductive site.

Increased lymphocyte beta-adrenergic receptor density in progressive multiple sclerosis is specific for the CD8+, CD28- suppressor cell

Beta-adrenergic receptor density on T cells from healthy humans is greatest on suppressor cells (CD8+, CD28-) and the effect of catecholamines, secreted by the sympathetic nervous system, predominates on this subset. The sympathetic skin response, a measure of sympathetic nervous system function, is absent in most patients with chronic progressive multiple sclerosis (MS). We measured beta-adrenergic receptor density on suppressor cells, cytotoxic cells, and monocytes from patients with chronic progressive MS and healthy control subjects. Control receptor density on suppressor cells was 2.8 +/- 0.3 fmol/10(6) cells versus a density of 5.1 +/- 0.7 fmol/10(6) cells for patients. Cytotoxic cell (CD8+, CD28+) receptor density was 1.4 +/- 0.4 fmol/10(6) cells in control subjects and 0.9 +/- 0.3 fmol/10(6) cells in the patients. Monocytes displayed beta-adrenergic receptor densities of 2.6 +/- 0.4 fmol/10(6) cells in normal individuals and 2.7 +/- 0.4 fmol/10(6) cells in the patient group. CD8 lymphocyte beta-adrenergic receptor densities in patients with relapsing-remitting and those with stable MS were not different from control values, yet were significantly less than the values for patients with chronic progressive MS. We find that mononuclear cells from healthy control subjects and patients with chronic progressive MS proliferate in response to 200 units/ml of recombinant human interleukin-2 (IL-2) similarly. However, IL-2 treatment increased beta-adrenergic receptor density on normal mononuclear cells, but failed to increase it on mononuclear cells from patients with chronic progressive MS.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunohistology of lymph nodes draining local skin reactions (chancres) in sheep infected with Trypanosoma congolense

Marked enlargement of lymph nodes draining local skin reactions (chancres) occurred in sheep following intradermal inoculation of cultured metacyclic forms of Trypanosoma congolense. Histologically, these lymph nodes were characterized by follicular hypertrophy and hyperplasia, compression and relative reduction of the paracortical areas and expansion of the medullary regions. Immunohistochemical staining with monoclonal antibodies to ovine lymphocyte subsets and Fc receptor (FcR) bearing macrophages, revealed increased expression of B cells (CD45R+), major histocompatibility complex (MHC) Class II, FcR+ macrophages, and CD1+ cells in the cortical and paracortical areas. The paracortical areas were found to be sparsely populated by CD5+, CD4+ and CD8+ cells, while the medullary areas contained numerous CD8+ cells and FcR+ macrophages. FcR+ macrophages were also present in cortical trabecular and subcapsular sinuses. As the chancre regressed, lymph node reactivity also subsided and fewer B cell follicles were observed and there was decreased expression of CD45R+ and MHC Class II+ cells.

Primed and naive helper T cells in labial glands from patients with Sjogren's syndrome

This study has investigated the presence and distribution of B cells, T cells and T-cell subsets within labial glands of patients with primary Sjogren's syndrome (n = 9) and secondary Sjogren's syndrome associated with rheumatoid arthritis (n = 8) using a sequential double immunoperoxidase technique and true colour image analysis. The composition of the inflammatory infiltrates was similar in glands from both patient groups. B cells were normally present within large foci with few detected in diffuse infiltrates such that the ratio of T:B cells in foci (2.4:1) was significantly lower than in diffuse infiltrates (7.3:1; P less than 0.001). In all infiltrates helper T cells (CD8-, CD3+) predominated over suppressor/cytotoxic cells (CD8+, CD3+; 2.7:1). Analysis of primed (CD45RA-, CD45RO+) and naive (CD45RA+, CD45RO-) CD8- T cells showed that the ratio of the primed to naive subset was significantly higher in focal (4.2:1) compared to diffuse (1.5:1; P less than 0.001) areas of lymphoid infiltration. These results indicate that the focal lymphocytic infiltrates characteristic of Sjogren's syndrome contain B cells associated with a T-cell population consisting predominantly of primed CD8- helper T cells. This latter population may be responsible for upregulating glandular B-cell activity in Sjogren's syndrome.

CD8 lymphocytes during Epstein Barr virus (EBV) infection: A CD29 positive population is expanded in acute infectious mononucleosis

The expression of phenotypic markers on CD4 and CD8 lymphocytes during the acute and convalescent phases of Epstein Barr virus (EBV) induced infectious mononucleosis was examined by two colour flow cytometry. Activated CD8 cells constitute the major population increased during acute infectious mononucleosis; in this phase we observed a preferential expansion of the CD8 CD29+ compared to the CD8 CD45RA+ cells. Serum soluble CD8 levels were also raised during the acute phase and a correlation with CD8 CD38+ and CD8 CD29+ cell numbers was found. The convalescent phase of infectious mononucleosis was characterized by a progressive return of CD8 subset and of soluble CD8 to baseline normal values. These results demonstrate that acute EBV infection induces the expansion of a CD8 subset with peculiar surface antigenic profile.

Heterogeneity of the CD8 lymphocytes in healthy and HIV 1 infected subjects

CD8 lymphocytes have been subdivided on the basis of Leu2 antigen cell surface density and coexpression of Leu4 and Leu11 antigens in two categories: Leu2bright and Leu2dim. Some CD8 lymphocyte phenotypes present in small percentages in some subjects do not come under these subsets. Flow cytometry analysis moreover shows that the distribution of fluorescence intensity tends to aggregate in most subjects in three distinct spots, here called Leu2HD, ID, and LD. The first, defined by fluorescence levels higher than 450, corresponds to the area of the Leu2+ Leu4+ lymphocytes that express the Leu7 antigen. These cells are all Leu11- and reach remarkably higher percentages in subjects with HIV 1 infection. They are totally included in the area of the Leu2bright cells, but their lowest level of fluorescence is higher. Our data seem to indicate a greater phenotypic homogeneity for these cells. The Leu2LD lymphocytes included in fluorescence levels lower than 175 are all Leu4-Leu11+ and 30% coexpress the Leu7 antigen. They are included in the fluorescence area of the Leud2dim cells, but reach medially lower fluorescence levels. The subset named LeuID has a mean fluorescence ranging between 175 and 450 and includes cells of the Leu4+ 11- and Leu4-11+ phenotypes. Moreover, HIV positive subjects exhibit very low percentages of Leu4+ 11+ and Leu4-11- cells. It is interesting to note that the Leu7 antigen density on the CD8 cell surface is highest for the Leu2HD lymphocytes and diminishes proportionally to the Leu2 antigen density in the Leu2ID and Leu2LD lymphocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of IL-2 receptor positive CD8(+)-T-lymphocytes grown from islets of NOD mice

IL-2 receptor positive T-cells from leukocyte-infiltrated pancreatic islets of diabetes prone or acutely diabetic NOD mice were propagated in vitro by culture in interleukin-2 containing medium. Of 13 lines obtained after limiting dilution all were positive for the T-cell marker Thy-1 and for CD8. Considerable heterogeneity in T-cell receptor usage was noted. Seven lines expressed T-cell receptors using V beta 8, one line was positive for V beta 5 and two lines expressed a non V beta 5, non V beta 8 receptor. Finally, two further lines lacked T-cell receptors. None of the cell lines were cytotoxic to islet cells although 10 lines showed non MHC restricted lysis of one or more tumour cells including rat insulinoma cells. We conclude that IL-2 receptor positive CD8+ T-lymphocytes from NOD islets are heterogenous with respect to V beta T-cell receptor usage. The majority of these cells are not cytotoxic to islet cells.

Large granular T lymphocytes, neutropenia and polyarthropathy: an underdiagnosed syndrome?

Thirteen patients with expansion of an unusual subset of T lymphocytes, defined by large size, cytoplasmic granularity and CD3+ CD8+ Leu 7+ surface phenotype, are reported. Although morphologically and/or phenotypically abnormal lymphocytes were found in all patients, only five had an absolute peripheral blood lymphocytosis. Ten patients had a bone marrow lymphocytosis. As in previous series, there was a strong association with neutropenia (12 patients) and polyarthropathy (seven patients). The latter group displayed a wide range of articular disease: classical or definite rheumatoid arthritis in four patients and milder non-erosive disease in the remainder. All 13 patients showed evidence of abnormal B cell function: IgM rheumatoid factor was present in nine patients, neutrophil-specific antibodies in six and all showed an increased level of at least one immunoglobulin isotype. These patients may be difficult to distinguish from those with idiopathic neutropenia and Felty's syndrome. Such a distinction may not be made on clinical grounds alone: critical assessment of lymphocyte morphology, bone marrow examination and analysis of lymphocyte phenotype should be considered in all patients with unexplained neutropenia, particularly in the context of arthritis. It is suggested that the true prevalence of this syndrome may have been greatly underestimated.

Murine T-lymphomas corresponding to the immature CD4-8+ thymocyte subset

N-methyl-N-nitrosourea induces murine CD4-8+ T-lymphomas that express high levels of J11d and low levels of CD5 antigens, a phenotype characteristic of immature CD4-8+ thymocytes. This assignment is supported by the fact that CD4-8+ lymphoma cell lines acquire CD4 expression after intrathymic (i.t.) transfer, a finding consistent with the established precursor potential of the normal immature CD4-8+ subset. CD4+8+ lymphomas recovered after i.t. transfer maintain a CD4+8+ phenotype in long-term culture. Northern blot analyses reveal that CD4 expression is regulated at the transcriptional level in immature CD4-8+ and CD4+8+ cell lines. CD4-8+ lymphomas express low levels of functional CD3/TCR complexes that mediate intracellular Ca2+ mobilization in response to CD3 or alpha/beta-TCR monoclonal antibody. These data suggest that the immature CD4-8+ subset contains cells capable of undergoing TCR-mediated signaling and selection events. In contrast to normal immature CD4-8+ cells, which comprise a heterogeneous and transient subset, the CD4-8+ lymphoma lines provide stable, monoclonal models of the immature CD4-8+ stage of thymocyte development.

Number of helper T cells and phytohemagglutinin stimulation correlate in cancer patients

Mononuclear cells from 12 normal controls (co), 10 advanced untreated (c1), and 6 advanced treated cancer patients (c2) have been isolated. The numbers of mononuclear cells bearing Leu1, Leu2, Leu3, Leu2/HLA-DR and LeuM3 were measured with a fluorescence-activated cell sorter. Only the quantity of helper T cells (Leu3) was decreased in cancer patients (co: 0.89, cl: 0.32, c2: 0.44 x 10(9)/l). Expression of all other markers, including activated suppressor T cells (Leu2/HLA-DR), did not differ significantly from the control. The proliferation of the lymphocytes was determined in a phytohemagglutinin-culture assay. The cancer groups showed a significantly decreased response (co: 95.8 x 10(9), cl: 28.7 x 10(9), c2: 25.7 x 10(9) cpm). These values correlated with the number of helper T cells but not with the suppressor T cells. Monocytes of cancer patients absorbed significantly more immunoglobulins than the monocytes of controls. The addition of indomethacin or isoprinosine to phytohemagglutinin-culture assay increased the proliferation of lymphocytes from both the cancer patients and normal controls.

Different subpopulations of developing thymocytes are associated with adherent (macrophage) or nonadherent (dendritic) thymic rosettes

Thymic rosettes (ROS), structures consisting of thymic lymphoid cells attached to a central stromal cell, were isolated from mouse thymus by collagenase digestion and unit-gravity elutriation. The ROS were then separated into those where the stromal cells were either macrophage-like (M-ROS) or dendritic cell-like (D-ROS), on the basis of the differences in adherence properties or in the level of MAC-1 surface antigen. The ROS were then dissociated and the thymocyte content analyzed by immunofluorescent staining and flow cytometry. M-ROS and D-ROS differed in thymocyte composition, although the major component of both was the CD4+CD8+ cortical thymocyte. D-ROS were enriched in thymocytes expressing high levels of surface T-cell antigen receptor (TcR) and the associated CD3 complex, and these included both CD4+CD8-CD3++ and CD4-CD8+CD3++ mature thymocytes. M-ROS were enriched in CD4-CD8- thymocytes and had a reduced content of thymocytes expressing high TcR-CD3 levels; they nevertheless contained some mature thymocytes, but only of the CD4+CD8-CD3++ category. Several lines of evidence indicated that the mature thymocytes in ROS were cells recently formed in the cortex, and were not from the medullary pool. ROS-associated mature thymocytes expressed lower levels of H-2K than free, mature thymocytes. The CD4+CD8+CD3++ subpopulation, believed to be a developmental intermediate between cortical thymocytes and mature T cells, was present in both ROS populations. Further, late intermediates leading to both mature T-cell categories were evident in D-ROS, but only those leading to CD4+CD8-CD3++ T cells were evident in M-ROS. The results are compatible with a role for ROS in TcR-specificity selection and in the final maturation steps in the thymic cortex.

Defective lectin-induced p55kDa-IL2R expression on peripheral T cells in non-Hodgkin's lymphoma patients

We examined 19 non-Hodgkin's lymphoma patients for their responsiveness to lectin stimulation, as measured by T cell proliferative response and p55kDa-IL2R expression. Our results indicate that both these responses were remarkably depressed in non-Hodgkin's lymphoma patients and the deficiency of lectin-induced p55kDa-IL2R expression correlated closely with the reductions in the lectin-induced T cell proliferative responses. The evidence that costimulation with PMA can partially overcome the IL2R defect might allow us to localize the cellular defects and rationally design chemotherapeutic agents corrective for these patients' poor p55kDa-IL2R inducibility.

Uptake of oligodeoxyribonucleotides by lymphoid cells is heterogeneous and inducible

Oligonucleotide uptake was studied in cultured murine spleen and lymph node cells using internally radiolabeled and fluorescein-5-isothiocyanate (FITC)-labeled oligonucleotides. Lymphoid subpopulations were distinguished by flow cytometry and staining with antibodies to cell-surface molecules. Approximately 5% of fresh lymphoid cells take up substantial amounts of oligonucleotide. The percentage of B cells that take up oligonucleotide increased fivefold if cells were cultured for at least 24 hr prior to incubation with labeled oligonucleotides, and increased 10-fold if cells were precultured for 48 hr. T-cell uptake changed very little in culture. Cultured CD4+ and CD8+ T cells had similar oligonucleotide uptake that was less than one-third of that in cultured B cells, but CD4-CD8- T cells had a higher percentage of cells taking up oligonucleotide than did B cells. T- or B-cell mitogens caused markedly increased oligonucleotide uptake in T or B cells, respectively. Oligonucleotide uptake could be inhibited only partially with competitor DNA. To distinguish between cell membrane-bound and intracellular oligonucleotide, cells were washed in acid glycine buffer (which removes most surface oligonucleotide). This demonstrated that most of the oligonucleotide was intracellular. We conclude that oligonucleotide uptake is quite heterogeneous among cultured cells, and that this uptake is inducible by mitogens. These data may be important for the design and interpretation of in vitro experiments, and for the planning of in vivo therapy with antisense oligonucleotides.

Role of CD8 T cells in rat IgE responses

The role of the cytokines interleukin-4 and interferon-gamma in the regulation of IgE responses in the mouse and man have focused on the role of CD4 T cells. In the rat, antigen-specific CD8 T cells, generated following inhalation of antigen, have been shown to be capable of suppressing IgE responses. Repeated intraperitoneal injections of 1 ng ricin and 1 microgram antigen established a long-lived IgE response in both low- and high-IgE responder rat strains (Wistar and Brown Norway). The duration of the IgE antibody response was 204 and 248 days, respectively. Total IgE levels rose from 30 +/- 20 to 39,000 +/- 7,500 ng/ml in the Wistar rat and from 120 +/- 100 to 47,000 +/- 8,000 ng/ml in the Brown Norway rat. An even greater (10(4)-fold) increase was seen in antigen-specific IgE antibody levels. Ricin alone had no effect and concomitant or prior stimulation with antigen was required. The proportion of CD4+ and CD8+ cells present in the spleen at the peak of the IgE response was markedly increased compared with animals given ricin or antigen alone. Furthermore, CD8 T cells were approximately 100 times more sensitive to ricin than CD4 T cells. These data suggest that enhancement of IgE responses in ricin-treated animals results from the selective deletion of T cells which suppress IgE and are of the CD8 phenotype.

Appearance of the T-cell marker CD8 on B chronic lymphatic leukemia cells in long-term cultures

Long-term cultures of highly purified B chronic lymphatic leukemia cells (B-CLL), were established. The B-CLL lymphocytes acquired the CD8 T cell marker in long-term cultures while still retaining their surface immunoglobulins. In confirmation of previous results, the cultured B-CLL lymphocytes released factor(s) into the culture medium that suppressed the allogeneic mixed-lymphocyte reaction. No correlation was found between the appearance of the CD8 T cell surface marker and onset of suppressor activity.

Developmental expression of IL-2-receptor light chain (CD25) in the chicken embryo

Thymocyte differentiation obeys the same fundamental principles in mammals as in avian species. This parallelism does not only affect the developmentally controlled acquisition of CD3, 4, 8, and TcR isotype expression, but also concerns CD25, the light chain of the interleukin-2 receptor (IL-2R). On chicken thymocytes, surface CD25, which is recognized by the monoclonal antibody INN Ch16, is first observed during day 11 of embryonic life, and peaks at day 14, when it is expressed by about one-third of all lymphoid cells. CD25 is found on subsets of all thymocyte populations as defined by TcR alpha beta, TcR gamma delta, 2, CD4, and CD8 expression, cortical or medullary localization, and is also present on a subset of intrathymic nurse-cell lymphocytes. These findings suggest phylogenetic conservation of the IL-2/IL-2R-triggered differentiation pathway previously described for mammalian species, thus underlining its probable functional importance.

Enhanced expansion of the thymic CD8+ cell subset as a potential mechanism for the generation of enhanced antitumor cytotoxicity by thymocytes from low-dose melphalan-treated MOPC-315 tumor bearers

We have previously shown that thymocytes from low-dose melphalan (L-phenylalanine mustard)-treated MOPC-315-tumor-bearing mice (melphalan TuB) are able to generate an enhanced level of anti-MOPC-315 cytotoxicity, as compared to thymocytes from untreated MOPC-315-tumor-bearing mice or thymocytes from untreated or low-dose melphalan-treated normal mice, upon in vitro stimulation with MOPC-315 tumor cells in the presence of a low concentration of recombinant interleukin-2 (rIL-2). Here we show that the generation of enhanced anti-MOPC-315 cytotoxicity by melphalan TuB thymocytes depends on the ability of the thymocytes to proliferate. In addition, the ability of melphalan TuB thymocytes to generate an enhanced level of anti-MOPC-315 cytotoxicity correlated with their ability to proliferate more readily than thymocytes from untreated tumor-bearing mice and thymocytes from untreated or melphalan-treated normal mice in response to stimulation with MOPC-315 tumor cells plus a low concentration of rIL-2. Moreover, although fresh melphalan TuB thymocytes do not contain a higher percentage of phenotypically mature cells (i.e., CD4-/CD8+ or CD4+/CD8-) than do thymocytes from normal mice or untreated tumor-bearing mice, after a 5-day culture with both MOPC-315 tumor cells and a low concentration of rIL-2, cultures of thymocytes from melphalan TuB contained a much higher percentage of CD4-/CD8+ (but not CD4+/CD8-) cells than did cultures of thymocytes from the other two sources. Since CD4-/CD8+ cells were previously shown to be responsible for the exertion of antitumor cytotoxicity by thymocytes stimulated with MOPC-315 in vitro, our results indicate that the enhanced antitumor cytotoxicity exerted by melphalan TuB thymocytes following in vitro stimulation with MOPC-315 tumor cells in the presence of a low concentration of rIL-2 is due, at least in part, to an expansion of the pool of CD4-/CD8+ effector cells.

T-lymphocyte subpopulations in pregnant women with newly diagnosed type 1 diabetes

The thymus-dependent immune system is involved in the disease process underlying Type 1 diabetes. Several studies have thus shown the distribution of peripheral T-lymphocyte subsets to be altered in diabetics. Unlike many other autoimmune diseases which improve during pregnancy, Type 1 diabetes has a higher incidence in pregnant than in non-pregnant women. Therefore, in this study the distribution of lymphocyte subpopulations in the blood was examined in pregnant, newly diagnosed Type 1 diabetic patients and compared with values from non-pregnant patients and healthy controls. The pregnant diabetics displayed a higher percentage of CD8+ cells (28.4 +/- 1.2%) than the non-pregnant diabetics (21.6 +/- 1.3%, p less than 0.005), but did not differ from the controls (29.0 +/- 1.3%). The CD3+ and CD4+ cell distribution displayed no significant difference within the groups. Among the pregnant diabetics a positive correlation was found between the percentage of CD4+ cells and the week of pregnancy when diabetes was diagnosed (p less than 0.01). No other correlations between immunological and clinical parameters were found. Thus the subsets of immune cells are not changed in an autoimmune direction for pregnant, newly diagnosed Type 1 diabetics as they are for non-pregnant. Therefore, the increased incidence of Type 1 diabetes in pregnant women is unlikely to be due to intensified autoimmune alterations in the immune system, but rather to changes induced in the beta-cells during pregnancy as discussed.