A human leukocyte antigen identified by a monoclonal antibody

Leukocyte antigen of approximate molecular weight 200,000 daltons have beendescribed in mouse, rat, and man. We described here the reactivities of a monoclonal antibody. GAP 8.3, which identified such an antigen on human leukocytes. We found the leukocyte antigen H-T200 on T and B lymphocytes, granulocytes, monocytes, and platelets, but not on erythrocytes or nonhematopoetically derived cells. Resting and activated T cells had more antigen or their surfaces than did resting B lymphocytes and EBV-transformed B cells, respectively. The leukocyte antigen was detected on approximately 75% of bone marrow cells; cells of the erythroid series comprised the negative population. The GAP 8.3 antibody and its F(ab′)₂ fragments had no effect on in vitro stimulation of peripheral blood cells by mitogens or allogeneic cells. Antigen isolated from T cell lines had a higher electrophoretic mobility than did antigen from B cell lines; antigen from the mycloid line U937 comigrated with that from B cell lines. In addition, we detected very small but reproducible differences in the electrophoretic mobility of the antigen on two T cell lines.     

Lymphocyte subpopulation profiles and mitogen kinetics in immunological deficiency testing

The correlation between lymphocyte proliferative responses to mitogens and T4/T8 ratios was analyzed in a cross section of patients who either were in a high-risk group for HTLV-III infection or fulfilled clinical criteria for acquired immune deficiency syndrome (AIDS). The patient results showed that, correlated with decreased T4/T8 ratios, there was a decrease in mitogen responsiveness first to pokeweed mitogen (PWM), followed by concanavalin A (Con A) and then phytohemagglutinin (PHA). Parallel to this decrease there was a shift toward higher concentrations of mitogens needed for optimal proliferation. In comparison, depletion of T4⁺ lymphocytes from normal healthy controls also decreased lymphocyte proliferative responses to all three mitogens but shifted the amount of mitogen needed for optimal proliferation toward lower concentrations. The differences in mitogen-induced proliferation between patients and healthy controls suggest a model whereby there is a functional defect(s) in mitogen responsiveness of the remaining T4^– lymphocyte population that can be overcome when higher concentrations of mitogen are used.     

A microculture system for generating haemolytic antibody responses from human tonsillar lymphocytes.

Small numbers of Ficoll-Hypaque purified human tonsillar lymphocytes were stimulated with PWM to produce SRBC-specific PFC in a microculture system. The magnitude of the response varied among different tonsils but was typically between 200 and 1000 PFC/10(6) cells cultured. Little or no response was observed in the absence of PWM. SRBC failed to stimulate a SRBC-specific response and the presence of this antigen in PWM-stimulated cultures depressed the response. The time of the maximum response was inversely related to the number of cells cultured. In addition, the duration of the response was limited by rapid depletion of critical medium requirements and/or build up of inhibitory factors especially when the cell concentration exceeded 5 x 10(5) cells/culture. This effect could be partially overcome by daily feeding of cultures with fresh medium. Fractionation studies indicated a requirement for both T and B cell populations. Constant efficiency of PFC production with respect to cell number could be achieved by the addition of inactivated autologous 'filler' cells. The significance of these results and applicability of the microculture system to a detailed analysis of human antibody responses will be discussed.     

In vitro effect of cadmium on primary antibody response to T-cell independent antigen (DNP-Ficoll)

The effect of various concentrations of cadmium on the in vitro primary antibody response to T-cell independent antigen (DNP-Ficoll) was investigated. Anti DNP-Ficoll antibody response in mice was significantly enhanced by 8 microM cadmium, but suppressed by 20 and 40 microM cadmium. However, cell viabilities were decreased by cadmium exposure with dose-dependent relationships. The results suggest that in vitro exposure to cadmium produces different effects on antibody responses.     

Nonsuppression of cortisol in depression and immune function

Eighteen depressive patients and twenty-five healthy control subjects were studied using a comprehensive immunological test system and the dexamethasone suppression test (DST) as well as some additional neuroendocrine parameters. In addition, immune functions of six of the patients were studied serially three times at 1-2 month's intervals. The OKT 4+/8+ ratio (OKT 4+ = helper/inducer phenotype; OKT 8+ = suppressor/cytotoxic phenotype) was slightly higher in those ten depressive patients showing suppression in the DST than in healthy controls, but there were no significant differences between the nonsuppressor and suppressor groups or between the nonsuppressor and suppressor groups or between nonsuppressors and control subjects. Lymphocyte transformation responses induced by phytohaemagglutinin (PHA) were similar in the nonsuppressors and suppressors, but lower in both groups than in control subjects. The number of Ig-secreting cells measured in the absence and presence of pokeweed mitogen (PWM) were similar in the nonsuppressor and suppressor groups. Four of the depressive patients tested repeatedly exhibited an abnormal response in the DST at the beginning of the study. During the follow-up period two of them recovered completely from depression as well as the patients with a normal suppression in the DST. The proportions of T and B lymphocytes and regulatory T lymphocyte subsets as well as the functions of T and B lymphocytes of the nonsuppressors and suppressors in the DST were within normal ranges before and after recovery from depression and comparable to healthy controls in repeated testing. The results indicate that in spite of the importance of cortisol in immunoregulation, the increased cortisol secretion and typical resistance to dexamethasone suppression in endogenously depressive patients is not profoundly and consistently reflected in immune functions. Neither does normalization of cortisol responses induce any major changes in immune status during a patient's recovery from depression. Previous work indicates that suppressed immunity may play an important role in the increased morbidity and mortality associated with bereavement. In the light of present findings we suggest that endogenous depression differs also in this respect from grief reactions.     

Abnormalities of B-cell activation and immunoregulation in splenectomized patients

Using a reverse hemolytic plaque assay as the effector system, we studied B-lymphocyte function in 12 patients after posttraumatic splenectomy, as well as in 25 normal individuals. The time interval between the splenectomy and the immunological studies varied between 2 days and 7 years. Compared to normal individuals, the splenectomized patients had markedly elevated numbers of spontaneous immunoglobulin-secreting cells (ISC) and severely decreased responses to the polyclonal activator pokeweed mitogen. A tendency towards normalization of these abnormalities, especially the high spontaneous ISC levels, could be observed during the time interval extending up to 7 years after splenectomy. In order to characterize the mechanism responsible for the altered immune response in splenectomized patients, co-culture experiments with unseparated and separated lymphocytes were performed. These revealed an impaired T-helper cell capacity as well as an intrinsic B-cell defect. Marker analyses with monoclonal antibodies revealed normal proportions with the exception of OKT 4 positive and B 1 positive cells that identify T-helper/inducer and peripheral B-cells respectively. We conclude that immune dysfunction in peripheral blood lymphocytes of splenectomized patients involves mainly the B-cell as well as the T-helper/inducer-cell population.     

Estradiol potentiates poke-weed mitogen-induced B cell stimulation in multiple sclerosis and healthy subjects

Female preponderance in many diseases suggested with autoimmune pathogenesis, multiple sclerosis (MS) being classified as one of them, indicates a role for hormonal factors such as estrogen in disease development. To bypass monthly hormonal fluctuations in females, we evaluated in male patients with MS and male blood donors the effect of 17-beta-estradiol on numbers of IgG, IgA and IgM producing cells in cultures of peripheral blood lymphocytes. While estradiol alone had no effect, estradiol in combination with poke-weed mitogen (PWM) yielded in both groups higher numbers of IgG and IgA producing cells when compared with numbers obtained by PWM stimulation alone, indicating an additory effect of estradiol to that of PWM on B cell maturation. This effect was less pronounced in MS than in blood donors, especially for IgG producing cells, probably reflecting higher B cell activation in vivo taking place in MS. On the contrary, cells producing IgG, IgA and IgM antibodies against myelin, myelin basic protein and measles virus were not detectable after stimulation with PWM, nor with PWM and estradiol. Estradiol can in many patients with MS and in blood donors be considered a potent co-activator of B cells in presence of B cell stimulating factor in the form of PWM.     

一种新型高频X线机设计

本文介绍了一种新型高频X线机的结构原理,并就其核心部分高频逆变器的结构进行了分析,最后给出了一种基于SG3525脉宽调制芯片实现闭环稳压控制方案,实验结果表明该方案的有效性和实用性。     

Functional Studies on Lymphocytes from Two Siblings with Congenital Hypogammaglobulinaemia

Two brothers with hypogammaglobulinaemia classified as common variable immunodeficiency (CVID) were investigated for distribution of peripheral blood lymphocyte (PBL) subpopulations, DNA synthesis and plaque-forming cell (PFC) capability of pokeweed mitogen (PWM) activated autologous and allogenic cocultures. Both patients had a decreased absolute number of T cells and normal or elevated levels of surface immunoglobulin (SmIg) bearing cells. Isolated B cells cocultured with autologous or allogeneic 4000 r irradiated T cells responded subnormally to PWM monitored by the ³H-thymidine incorporation in microcultures whereas B cells cocultured with allogeneic untreated normal T cells proliferated normally. PBL from parallel macrocultures of unfractionated or T/B separated patients' cells were not able to produce plaques using a reversed haemolytic protein A assay. Addition of glucocorticoid to unfractionated PBL did not reverse the unresponsiveness. In allogeneic co-cultures patients' untreated or 2000 r irradiated T cells induced a normal PFC response. Normal untreated T cells induced a reduced number of IgM- and IgG-PFC from patients' B cells but this response was almost eliminated using irradiated normal T cells. These results demonstrate a primary B cell defect in the patients and indicate an impaired cooperation between patients' B and T cells. Activation of patients' B cells to Ig secretion requires the presence of proliferating T cells.     

Inhibition of delayed hypersensitivity reaction in mice by cadmium

The effect of a single exposure to Cd on DH was studied through exposure to Cd at different time intervals in relation to antigen administration. Exposure to Cd significantly suppressed the DH reaction, with a dose-response relationship, when administered 2 or 3 days after immunization of BALB/c and DBA/2 mice with sheep red blood cells. A strain difference in sensitivity to Cd was also demonstrated. These results suggest that a single exposure to Cd impairs the cellular immune response in mice.