Genetic relationships between the HL-A system, the blood group systems (Rh, ABO) and the immune reactivity]

The authors examined in immunized healthy persons the correlations between the ability of immune response, the value of their different immunological parameters, and the HL-A blood-group antigens by computer analysis. Immune reactivity showed mosaic-like correlation against the HL-A system. The most definite negative correlation was noticed between the HL-A 3 and 7 antigens and the cytotoxic activity of lymphocytes. Remarkable and definite correlation was found between the Rh system and immune reactivity. The level of the natural antibodies, the immunoglobulins and the functions of lymphocytes were generally decreased in males in comparison to females.     

The human mixed-lymphocyte culture (MLC) interaction after in vivo allo-immunization. II. HL-A specificity of early proliferative response

Human volunteers were immunized with a single intradermal dose of allogeneic buffycoat cells. When donor and recipient differed for four HL-A antigens belonging to the first and second series, an increased MLC proliferation early in the cultures was observed when responding lymphocytes from the immunized individual were confronted with stimulating cells from his donor. These findings were not observed when the incompatibility between donor and recipient involved only one second series HL-A antigen. The specificity of the altered response was studied by confronting responding lymphocytes from the immunized individual with different third-party stimulating cells. Most of these combinations revealed an early increased proliferation compared to control combinations with responding lymphocytes from nonsensitized individuals. However, the early increased responsiveness was significantly more pronounced in combinations where the stimulating cells shared two or more “private” HL-A determinants with the immunizing donor. It is concluded that a major part of the early increased responsiveness is due to proliferation of lymphocytes with receptors for HL-A (SD) determinants.     

The cell mediated and humoral immune response to vaccination with acellular and whole cell pertussis vaccine in adult humans.

The cell mediated immune response (CMI) against pertussis antigens following vaccination with the traditional Danish whole cell pertussis vaccine (WC-P) and the Japanese acellular pertussis vaccine (A-PV) JNIH-3 was studied in four adult human volunteers. Vaccination with the A-PV induced an in vitro proliferative response of peripheral blood lymphocytes to pertussis toxin (PT) subunits S2-S4, S3-S4 and S5 and the filamentous hemagglutinin (FHA), and a better serological response to native PT, detoxified PT (dPT) and FHA than the WC-PV. The induced CMI and serological response were followed over a period of 17 weeks, and were not seen to decline during this period. Further, an in vitro proliferative response to Bordetella pertussis agglutinogen 2 and 3 were demonstrated using lymphocytes from recently and not-so-recently pertussis-vaccinated adults.     

Lymphocyte reactivity to autochthonous tumor cells in dogs with spontaneous malignancies

Lymphocyte reactivity to autochthonous tumor cells was determined by using fresh, incubated, cryopreserved, or trypsinized tumor cells from 29 dogs with malignant lymphoma and 24 dogs with solid tumors. Lymphocytes were stimulated in vitro by autochthonous irradiated tumor cells and, after 6 days in culture, incubated with [³H] thymidine. The ratio of cpm of stimulated over nonstimulated cultures was determined. In 18 of 29 lymphoma dogs and 15 of 24 solid tumor dogs, significant reactivity of lymphocytes to autochthonous tumor cells was seen. No consistent effect of autologous serum on lymphocyte reactivity was found. It was concluded that tumor cells from most dogs with spontaneous malignancies have tumor-associated antigens capable of stimulating autochthonous lymphocytes in culture.     

Correlation of tuberculin-induced lymphocyte transformation with skin test reactivity and with clinical manifestations of sarcoidosis

In vitro lymphocyte reactivity to tuberculin (PPD) was studied in buffy coat cultures from 87 patients with sarcoidosis and from 64 controls. A strong correlation was found between PPD-induced lymphocyte transformation and skin reactivity. No significant differences were found in the in vitro response of lymphocytes from skin test positive patients with sarcoidosis and from controls with the same degree of skin test reactivity. In patients with sarcoidosis negative to 100 TU, tuberculin sensitivity could be demonstrated in vitro significantly more often than in comparison subjects. Both in vivo and in vitro tuberculin sensitivity and “spontaneous” transformation were significantly more frequent in patients with erythema nodosum.     

Tuberculin response of lymphocytes from human skin test nonreactors; evidence for in vitro primary sensitization of T lymphocytes.

Tuberculin-purified protein derivative (PPD) is a B-lymphocyte mitogen in a variety of experimental animals. Although peripheral blood mononuclear cells (PB MNC) from healthy human tuberculin responders consistently responded to PPD by increased incorporation of [³H]thymidine, cell fractionation studies showed this to be due to T-lymphocyte rather than B-cell blastogenesis. Moreover, utilizing thymidine suicide experiments, the T-lymphocyte response could be categorized as antigenic rather than nonspecific mitogenic reactivity. Kinetic studies revealed a delayed peak of PPD-induced thymidine incorporation in PB MNC from tuberculin skin test-negative as compared to skin test-positive donors. This suggested in vitro primary sensitization of T lymphocytes to PPD, which was corroborated in experiments demonstrating tuberculin reactivity of human umbilical-cord blood lymphocytes.     

Quantitative study of deoxycytidine incorporation in large and small lymphocytes of the mouse

Using radioautographic smear preparations of thymocytes and mesenteric lymph node (MLN) cells labelled with three different tritiated pyrimidine deoxyribonucleosides, the incorporation of DNA precursors was studied separately on large lymphocytes and small lymphocytes. Radioautographic reaction due to generally tritiated deoxycytidine ( [G-3H]CdR) labelling in vivo in large lymphocytes was more intense than that in small lymphocytes. When mice were sacrificed 6 hr after the administration of tritiated thymidine ( [3H]TdR), small lymphocytes were labelled more heavily than large lymphocytes. However, labelling intensity with [3H]TdR in large lymphocytes was greatly enhanced by the administration of 5-fluoro-deoxyuridine, whereas in small lymphocytes labelling intensity was only fairly enhanced by the same treatment. When cells were incubated in vitro with 5-tritium labelled deoxycytidine [( 5-3H]CdR) for 10 min, there was no significant difference in labelling intensities between large and small lymphocytes. In the case of [G-3H]CdR incorporation, the labelling intensity in large lymphocytes was found to be significantly stronger than that in small lymphocytes. Large as well as small lymphocytes incorporated [3H]TdR very well in vitro. However, addition of 5 X 0 X 10(-5) M of non-radioactive CdR to the medium greatly decreased the incorporation of [3H]TdR by large lymphocytes, whereas the effect of non-radioactive CdR in small lymphocytes was not so marked as that in large lymphocytes. Furthermore, the [3H]TdR-labelling percentages were decreased at the same rate by the addition of non-radioactive CdR in both large and small lymphocytes. These results indicate that large lymphocytes and a proportion of small lymphocytes have a strong tendency to convert CdR to thymidine mono-phosphate, which is utilized for DNA synthesis, whereas this ability is relatively weak in the rest of small lymphocytes. Thus, it is probably that this metabolic ability changes during the transition of the large lymphocyte to the small lymphocyte.     

Secondary response on in vitro primed human lymphocytes to allogeneic cells

In vitro primed human cells have been shown to proliferate and to generate cytotoxic effector cells only when triggered by MLR-S determinants; they do not respond to HL-A antigens alone (i.e., they behave in this respect as unprimed cells). In contrast, in vivo-primed mouse spleen cells acquire the ability to proliferate and to generate cytotoxic effector cells even when triggered by cells artifically depleted by physical means of MLR-S activity or by cells, such as fibroblasts, normally devoid of MLR-S activity. For this reason, peripheral blood lymphocytes (PBL) from immunized volunteers were studied and the immunogenetic requirements of such in vivo-primed cells were compared to those of the in vitro-primed cells.Both in vivo- and in vitro-primed PBL were found to obey the same Laws: (a) proliferation is induced only by MLR-S disparities and is not induced by HL-A disparities alone; (b) proliferation appears to be specific for a given MLR-S; (c) specific cytotoxic effectors are generated by either a specific MLR-S stimulus or a third party-cell stimulus; (d) nonspecific mitogens can also, generate memory cytotoxic effector cells from a preimmunized cell population. However, the expression of such an immune status by PBL is short-lived, suggesting homing in privileged sites of the immune memory cells.     

Dipetalonema viteae: in vitro blastogenesis of hamster spleen and lymph node cells to phytohemagglutinin and filarial antigens

Hamsters of the randomly bred LAKZ and inbred LSH strains were infected with Dipetalonema viteae, and the in vitro responses of lymph node and spleen lymphocytes to male and female worm antigens and phytohemagglutinin (PHA) were measured by a [³H]-thymidine-uptake assay at various times after infection. The PHA response remained unchanged at the level of controls in infected LAKZ hamsters while LSH hamsters showed a depressed response to the mitogen during late infection. Stimulation of lymph node cells by filarial antigens was maximal in both strains of hamsters at Week 4 postinfection, almost reaching values obtained in PHA stimulated cultures. A similar high lymphocyte transformation reaction was measured after the injection of dead third stage larvae. During transient microfilaremia, when antibody titers reached a maximal level, the lymphocyte reactivity to filarial antigens decreased drastically and only occasionally was demonstrated in hamsters 20 and 30 weeks after infection. No correlation between lymphocyte reactivity and parasitological findings (worm load or intensity and duration of microfilaremia) could be demonstrated. The cellular unresponsiveness to filarial antigens was further analyzed in chronically infected LAKZ hamsters. No suppressor cells could be found in lymphocyte suspensions of nonresponding hamsters. A challenge infection did not restore lymphocyte reactivity. Serum of chronically infected hamsters caused marked inhibition when added to filarial antigen-sensitive lymphocytes. Lymphocytes from hamsters with a mixed D. viteae and Schistosoma mansoni infection responded as well to soluble schistosomal egg antigens at Week 30 of a D. viteae infection as lymphocytes from hamsters infected with S. mansoni alone. The humoral immune response to schistosomal antigens, however, was significantly lower in animals with a mixed infection.     

The effect of heating and drugs on HL-A antigens and their reactions with cytotoxins]

In some instances the heating of lymphocytes for 2 to 3 minutes at 56 degrees C enhances HL-A antigens or makes it possible to detect these antigens by a twostage microlymphocytotoxic test on preheated lymphocytes only. Similar phenomenons are observed in some tannin (1: 40 000) or 0.1% phenol-treated lymphocytes and after the addition of these solutions during the first stage of the lymphocytotoxic test. Prolonged heating at 56 degrees C leads to nonspecific polyreactivity of lymphocytes, giving false results with all sera. For similar reasons also higher concentrations of tannin and phenol solutions were found dissatisfactory for the pretreatment of lymphocytes. The pretreatment of lymphocytes with 36-0.5% formaline induces full inhibition of specific cytotoxic reactivity of HL-A antigens and their absorption ability with regards to respective HL-A sera. The addition of formaline at 0.06-0.3% concentration during the first and second stages of the test and at the end of the second stage (or simultaneously with eosine) gives also negative results of the cytotoxic test owing to the inhibitory effect of formaline on rabbit complement and HL-A antigens.     

Secondary response of in vitro-primed human lymphocytes to allogeneic cells

In vitro-primed human lymphocytes proliferate in a secondary mixed lymphocyte reaction (MLR) under the control of MLR-S specificities. HL-A antigens are unable to induce a secondary Proliferation. In familial haploidentical combinations, the secondary proliferation is specific for the priming MLR-S specificity, i.e., as early as 24 to 48 hours after the re-stimulation, a clearcut response is observed toward the sensitizing MLR-S specificity. The secondary response is reflected in acceleration of the reaction rather than in the peak of (³H) TdR uptake. However, when either haploidentical familial primed responding cells or unrelated cells primed toward MLR-S homozygous cells were used, no early typing response was observed against unrelated cells. The level of (³H) TdR incorporation toward cells which possessed and those which did not possess the priming specificity was identical until day 3–4. Noneless, the peak response toward cells possessing the priming MLR-S specificity occurs regularly 24 to 48 hours prior to the peak response toward the cells negative for the priming specificity (day 3–4 as opposed to day 5). Technical improvements are therefore needed before such a technique will provide a clearcut MLR-S typing methodology.     

Fate of HL-A antigens in aging cultured human diploid cell strains : II. Quantitative absorption studies

The expression of histocompatibility antigens on cultured human fibroblasts was studied utilizing a quantitative microabsorption assay. Trypsin treatment of cultured human embryonic and adult fibroblasts did not change their capacity to absorb selected HL-A alloantisera as compared with cells harvested by scraping. The density of HL-A antigens was found to remain unchanged throughout the finite in vitro lifetime of two human embryonic diploid cell strains (WI-38 and WI-26) and ten adult skin fibroblast cultures. Cultured fibroblasts derived from skin, lung, heart, and liver of one donor showed similar quantitative expression of HL-A1, 9, W5 and W16. These experiments support the contention that the HL-A marker system is at present the only system by which human fibroblasts derived from different normal human donors can be distinguished in vitro.     

Lymphocyctes Tgammadelta in clinically normal skin and peripheral blood of patients with systemic lupus erythematosus and their correlation with disease activity

Human Tgammadelta lymphocytes constitute from 1 to 15% of all peripheral blood lymphocytes. Recent work has demonstrated that this population plays a major role in the pathogenesis of infectious and immune diseases. Increased numbers of gammadelta T cells have been found in affected skin from systemic sclerosis and chronic cutaneous lupus erythematosus patients. In our study, we have determined the numbers of Tgammadelta lymphocytes and their subpopulations in peripheral blood from 29 patients with systemic lupus erythematosus (SLE) and in 19 healthy volunteers using flow cytometry and specific monoclonal antibodies. The same cells in uninvolved skin from SLE patients and human controls using immunohistochemical analysis were estimated. T-Cell receptor (TCR) delta chain gene rearrangement was identified with primers for Vdelta1, Vdelta2 and Vdelta3 by the polymerase chain reaction. Statistical analysis showed a significantly decreased number of gammadelta T cells in SLE patients (26.4+/-16.9/microl) compared with the control group (55.3+/-20.6/microl (p < 0.001). The number of Vdelta2 TCR+ and Vgamma9 TCR+ subpopulations was also lower in SLE patients than in healthy persons. No statistical correlation between disease activity and the number of gammadelta T cells was demonstrated. The percentage of Tgammadelta lymphocytes in clinically normal skin from SLE patients was twice (22.0+/-9.4%) that found in the skin from healthy persons (11.1+/-5.5%) (p < 0.002). Higher percentages of the Vdelta2 TCR+ and Vgamma9 TCR+ subpopulation of lymphocytes were found in the skin from SLE patients. We have also found positive correlation between the percentage of Tgammadelta lymphocytes in skin and the activity of SLE (r=0.594, p < 0.001), and between subpopulation Vdelta3 TCR+ and disease activity (r=0.659, p< 0.001). In conclusion, the results of our studies demonstrate that, in patients with SLE, accumulation of Tgammadelta lymphocytes can be seen in clinically normal skin, and the percentage of these cells correlates with the activity of the disease.     

Age and the response of peripheral blood lymphocytes to mitogens]

Reactions of the peripheral blood lymphocytes of normal persons from 19 to 49 years of age to the following mitogens was studied; phytohemagglutinin (PHA), concanavalin A (ConA), rabbit serum against human thymocytes (ATS). A significant reduction of the lymphocytes proliferative response to ConA was reported in persons above 30 years old. There was also demonstrated a significant negative correlation between the proliferative response indices and the donor's age (in ConA-stimulation-for the whole group examined, and in ATS-stimulation-for persons aged from 30 to 49 years only. Analysis of the intensity of thymidine-(3)H incorporation showed that with the advance of age there was a fall of the percentage of cells with an intensively labelled nuclei and an accumulation of cells with weakly labeled nuclei, this phenomenon was observed both when the proliferative response was decreased and when no significant differences were reported in these indices.     

Ischemia induced changes in expression of the astrocyte glutamate transporter GLT1 in hippocampus of the rat

Changes in cellular uptake of glutamate following transient cerebral ischemia is of possible importance to ischemia induced cell death. In the present study, we employed in situ hybridization and immunohistochemistry to investigate the influence of cerebral ischemia on expression of mRNA and protein of the astrocyte glutamate transporter GLT1, and of glial fibrillary acidic protein. Different subfields of CA1 and CA3 of the rat hippocampus were studied at various time-points after ischemia (days 1, 2, 4, and 21). In CA1, GLT1-mRNA was decreased at all time-points after ischemia except from day 2, whereas in CA3, decreases were seen only on day 1. Expression of GLT1-protein in CA1 was unchanged during the initial days after ischemia, but decreased markedly from day 2 to 4. In CA3, GLT1-protein increased progressively throughout the observation period after ischemia. Following the degeneration of CA1 pyramidal cells, a positive correlation between the number of CA1 pyramidal cells and expression of either GLT1-mRNA or -protein was evident selectively in CA1. Increases in expression of mRNA and protein of glial fibrillary acidic protein were present from day 2, most notable in CA1. The present data provide evidence that expression of GLT1 in CA1 of the hippocampus is not decreased persistently before the degeneration of CA1 pyramidal cells, but is downregulated in response to loss of these neurons. Since the reduction in GLT1 expression evolved concomitantly with the degeneration of CA1 pyramidal cells, it may contribute to the severity of CA1 pyramidal cell loss. A progressive postischemic increase in GLT1 expression in CA3 may be linked to the resistance of CA3 neurons to ischemic cell damage.     

Immune responses to Herpesvirus sylvilagus infection in cottontail rabbits

Immunologic changes produced by Herpesvirus sylvilagus infection of cottontail rabbits were investigated to evaluate this virus infection system as an animal model for EBV infection in humans. H. sylvilagus neutralizing antibodies appeared as early as 7 days after infection, peaked 2 to 4 wk postinfection and decreased to low levels by 8 to 10 wk postinfection. Complement-dependent antibodies mediating the protection of in vitro infection of monocytes and Con A-stimulated lymphoblasts with H. sylvilagus were observed as were complement-dependent cytotoxic antibodies against H. sylvilagus-infected cells. No cytolytic activity was present in sera taken either before or 3 days after infection; cytolysis was first observed 7 days after infection. The development of cytolytic antibodies appeared to be biphasic during an infection course of 12 to 16 wk. In vivo induction of a primary cytotoxic lymphocyte response to H. sylvilagus was also investigated. Splenic lymphocytes from infected animals lysed H. sylvilagus-infected skin fibroblasts; however, similar activity was not observed when PBMC or mesenteric lymph node lymphocytes were used as effector cells. H. sylvilagus-infected autologous skin fibroblasts were preferentially lysed as compared to heterologous skin fibroblasts. This virus-specific cytotoxic activity appeared 5 days postinfection and peaked 7 days postinfection. By 28 days postinfection, only low levels of cytotoxic activity were detected in spleen cells. Herpesvirus sylvilagus infection of cottontail rabbits provides an animal model for the study of lymphoproliferative disorders induced by herpesviruses.     

Secondary response of in vitro primed human lymphocytes to allogeneic cells

The secondary response of human lymphocytes primed in vitro with allogeneic lymphocytes is reported. Accelerated proliferation is observed ' both against the specific priming cell and against unrelated third party cells, but the intensity of proliferation against the specific cell is usually, but not always, higher than that against third party cells. To clarify the respective roles ofHL-A andMLR-S in the development of this secondary proliferative response, three kinds of cells were used from which MLR-S activity was supposed to have been abolished while serologically-defined HL-A antigens were present: (a) heattreated cells, (b) UV-treated cells, and (c) a recombinant betweenHL-A andMLR-S. Heat treated cells were unsatisfactory for this study, but UV-treated and recombinant cells showed thatMLR-S was sufficient and necessary both for priming and for eliciting a secondary proliferative response. No role could be found forHL-A or for a secondMLR-S locus positioned between the first and secondHL-A loci.     

Levamisole and bovine immunity: in vitro and in vivo effects on immune responses to herpesvirus immunization

Levamisole was shown to enhance in vitro blastogenic responses of bovine lymphocytes to nonspecific mitogens (phytohemagglutinin and pokeweed mitogen) as well as to infectious bovine rhinotracheitis virus and purified protein derivative. Greatest enhancement was observed at suboptimal concentrations of viral antigen. In addition to enhancing lymphocyte reactivity levamisole also affected macrophage activity as determined by increased Fc receptor activity and [3H]glucosamine incorporation. Levamisole (5-50 micrograms/mL) enhanced type II immune (or gamma) interferon production by macrophage-lymphocyte cultures. Administration of levamisole and attenuated infectious bovine rhinotracheitis vaccine virus in vivo did not elevate cellular or humoral responses.     

(3)H](2S,4R)-4-Methylglutamate: a novel ligand for the characterization of glutamate transporters

[(3)H](2S,4R)-4-Methylglutamate ([(3)H]4MG), used previously as a ligand for low-affinity kainate receptors, was employed to establish a binding assay for glutamate transporters (GluTs), as 4MG has also been shown to have affinity for the glial GluTs, GLT1 and GLAST. In rat brain membrane homogenates in the presence of Na(+) ions at 4 degrees C, specific binding of [(3)H]4MG was rapid and saturable (t(1/2) approximately 15 min), representing > 90% of total binding. Dissociation of [(3)H]4MG occurred in a biphasic manner, however, saturation studies and Scatchard analysis indicated a single site of binding (n(H) = 0.85) and a K(d) of 6.2 +/- 0.8 microM with a B(max) of 111.8 +/- 23.8 pmol/mg protein. Specific binding of [(3)H]4MG was Na(+)-dependent and inhibited by K(+) and HCO(3-). Pharmacological inhibition with compounds acting at GluTs revealed that Glu, D- and L-aspartate, L-serine-O-sulfate and Ltrans-pyrrolidine-2,4-dicarboxylate fully displaced specific binding. Drugs having preferential affinity for GLT1, kainate, dihydrokainate and Lthreo-3-methylglutamate, all inhibited approximately 40% of specific binding. The inhibition pattern of L-serine-O-sulfate in the presence of a saturating concentration of dihydrokainate was suggestive of [(3)H]4MG also labelling GLAST. 6-Cyano-7-nitroquinoxaline, a kainate receptor antagonist, and a range of Glu receptor agonists and antagonists failed to significantly inhibit [(3)H]4MG binding. The pharmacological profile of binding of [(3)H]4MG resembled that found for [(3)H]D-aspartate, a ligand specific for GluTs, reinforcing the hypothesis that [(3)H]4MG was labelling GluTs in this assay. Together, these data illustrate the development of an efficient, economic binding assay that is suitable for the characterization of different subtypes of GLuTs.     

The identification of HL-A antigens on fresh and cultured human endothelial cells.

Human endothelial cells were obtained from the umbilical cord veins of 16 newborns by methods previously described and tested for HL-A antigens by a microcytotoxicity method. HL-A antigens were present on all endothelial cell lines tested. When the HL-A phenotypes of fresh endothelial cells and autologous fetal lymphocytes were compared, a concordance of 70% was observed. When the HL-A phenotypes of maternal lymphocytes and fresh endothelial cells were compared, a maternal contribution to the endothelial cell phenotype was evident in 72% of the possible commmon antigens. Some HL-A antigens were deleted from 11 of 16 endothelial cell lines that were re-typed after 2 weeks in tissue culture. The majority (90%) of deleted antigens were from the second HL-A locus. When three lines of endothelials cells were again re-typed after 6 weeks in culture, no further changes in antigenicity were noted. These findings: a) demonstrate that HL-A antigens are present on human endothelium and suggest that endothelial cells are actively involved in establishing the immunogenicity of a graft, and b) demonstrate that the HL-A antigens on human endothelial cells may be modulated by in vitro culture.