Phenotypic characterization of lymphocyte subpopulations in horses affected with chronic obstructive pulmonary disease and in normal controls

The alterations in lymphocyte subsets in chronic obstructive pulmonary disease (COPD) in the horse were investigated by using monoclonal antibodies to identify CD3+, CD4+, CD8+, and surface immunoglobulin positive (sIg+) lymphocytes in peripheral blood, bronchoalveolar lavage fluid (BALF), and pulmonary biopsy frozen tissue sections. COPD-affected horses (n = 5) and normal controls (n = 5) were sampled prestabling and 14 days poststabling, at which time the COPD-affected horses wee exhibiting clinical signs of COPD. The peripheral blood absolute CD4+ lymphocyte count was significantly elevated in the COPD-affected horses pre- and poststabling. The CD4:CD8 ratio in peripheral blood of COPD-affect horses was unaffected by stabling, but the same ratio in the control horses was significantly decreased. These findings support a hypothesis of deficient regulation of a systemic immune response to indoor air in the COPD-affected horses. A large population of leukocytes in pulmonary biopsy immunohistochemical sections from both groups of horses appeared to be CD3+ CD4- CD8-, an uncommon phenotype in both the peripheral blood and BALF.

Effect of food restriction on life span and immune functions in long-lived Fischer-344 x Brown Norway F1 rats

Life-long food restriction is known to slow aging and reduce the rate of occurrence of age-associated disease processes, but the mechanism by which this is accomplished is unknown. In this study we have examined the effect of food restriction on the proliferative response of spleen cells to mitogens and lymphokine production in 6-, 18-, and 30-month-old AL and FR Fischer-344 x Brown Norway (F-344 x BNF1) female rats whose average life span is 137 weeks on an ad libitum (AL) diet and 177 weeks on a food-restricted (FR) diet. In addition, the ability of food restriction to recall antigens was tested in 10-month-old rats by immunizing them with keyhole limpet and hen's egg albumin and measuring proliferative response of draining lymph node cells to these antigens. Our results indicated that the spleen-cell proliferative response to phytohemagglutinin and concanavalin A (Con A) was equal in 6- and 18-month-old rats but declined significantly in 30-month-old AL rats compared to FR rats. Although flow cytometric analyses did not reveal differences for CD4, CD8, and Ig+ cells with age, a significant rise in memory T cells (Ox-22low) in both CD4+ and CD8+ T-cell subset lineage was noted in AL-fed rats at 30 months of age. In FR rats, however, only a minimal shift of naive T cells (Ox-22high) to memory cells was observed. In FR rats, the observed changes in the naive and memory T-cell subsets correlate well with the observed higher levels of the antiinflammatory interleukin-2 (IL-2) and lower levels of the proinflammatory cytokines such as IL-6 and tumor necrosis factor-alpha. The ability of food-restricted animals to recall antigens was lower compared to their age-matched controls, though the proliferative response to T-cell mitogen Con A and superantigen staphylococcal enterotoxin B was higher. These findings indicate that food restriction may selectively act to maintain a lower number of antigen-induced memory T cells with age, thereby maintaining the organism's ability to produce higher levels of IL-2 with age. In summary, the increased cell-mediated immune function noted in aged FR rats appears to be due to the presence of a higher number of naive T cells, which are known to produce elevated levels of the antiinflammatory cytokines, which may in part be responsible for reducing the observed age-related rise in disease.

Immunophenotypic characterization of tumor infiltrating lymphocytes and peripheral blood lymphocytes isolated from melanomatous and non-melanomatous Sinclair miniature swine

Selectively-bred Sinclair miniature swine exhibit a high incidence of congenital malignant melanoma which either proves fatal (10-15% of tumor-bearing piglets) or spontaneously regresses with a biphasic immunological phenomenon (85-90%) and no recurrence of malignancy. Mononuclear leukocytes were isolated from cutaneous melanomas and peripheral blood specimens collected from melanomatous (tumor-bearing) Sinclair swine during second-phase regression, and from peripheral blood specimens collected from non-melanomatous (tumor-free) Sinclair swine and control Hanford swine. Leukocyte identities were determined with single- and dual-parameter indirect immunofluorescence assays via flow cytometry. Assays for the specific surface antigens CD45, CD2, CD4, CD8, CD1, MHC class II, and N1 were employed to develop immunophenotypic profiles within the gated lymphocyte clusters from each TIL and PBL suspension. Significantly more CD8+ T-lymphocytes were identified in TIL suspensions than in peripheral blood leukocyte (PBL) suspensions (P < and = 0.05), regardless of breed or tumor status. Conversely, PBL suspensions contained significantly higher percentages of CD4+ T-lymphocytes than the levels found in TIL suspensions (P < and = 0.05). Virtually all TIL were MHC class II+, whereas the percentages of PBL expressing this antigen were markedly lower (P < and = 0.05). The percentages of T-lymphocytes co-expressing CD4 and CD8, a normal subset unique to swine, were generally consistent in all TIL and PBL suspensions examined. The results of this study have firmly established the immunophenotypic identities of cells associated with the second-phase regression phenomenon of this melanoma and have identified specific variations in the leukocyte profiles of the respective TIL and PBL suspensions.

Early pulmonary cell response during experimental maedi-visna virus infection

A model of experimental infection with EV1, a British isolate of maedi-visna virus (MVV), has been developed. Twelve male Texel sheep were allocated to three groups and inoculated by the respiratory route with different inocula. Six of the animals received 10(7.2) tissue culture infective dose (TCID50) of MVV EV1 strain. Two sheep were inoculated with the same dose of heat inactivated MVV EV1 strain. An additional group of four sheep was sham-inoculated with identically prepared virus-free culture media. Experimental infection was followed for 16 weeks. Prior to inoculation, routine haematology, bronchoalveolar lavage (BAL) and flow cytometric analysis of bronchoalveolar lavage fluid (BALF) lymphocytes were performed in all animals to provide baseline parameters. Flow cytometric analysis of BALF lymphocytes and differential BALF cell counts were performed. Precipitating antibodies to MVV developed in all MVV-inoculated animals during the first 4 weeks post-inoculation, while the rest remained seronegative to MVV. MVV-infected animals had significantly decreased (P < 0.05) percentages of macrophages and significantly increased (P < 0.05) percentages of lymphocytes in BALF 4 weeks post-inoculation. Phenotypic changes in BALF T lymphocytes from MVV-inoculated animals, compared with the other two groups, showed significantly decreased (P < 0.05) percentages of CD4+ and gamma delta + T lymphocytes, significantly increased (P < 0.05) percentages of CD8+ lymphocytes and significant inversion (P < 0.05) of the CD4+/CD8+ ratio at different sampling times, but between 2 and 12 weeks post-inoculation. These findings indicate that during experimental MVV-infection an early, short-term cellular reaction occurs in the lung, that is characterised by T lymphocyte phenotypic changes that are very similar, if not identical, to those observed in natural MVV infection.

Trypanosoma congolense: a comparison of T-cell-mediated responses in lymph nodes of trypanotolerant and trypanosusceptible cattle during primary infection

A comparison of T-cell-mediated immune responses in trypanotolerant N'Dama and susceptible Boran cattle during primary infection with tsetse-transmitted Trypanosoma congolense was conducted to assess whether different patterns of T-cell activation occurred during trypanosome infection. Proliferation and IFN-gamma synthesis in response to trypanosome antigens and to the mitogen Con A were measured in LNC before infection and 10 and 35 days postinfection. Phenotypic analysis of LNC was also carried out. No significant differences in the in vitro proliferation of LNC to VSG, to hsp70/BiP, or to Con A were detected between the breeds. In contrast, IFN-gamma production in response to Con A was higher in Boran cattle at 35 days p.i. A reduction in the number of CD2+ and CD4+ T-cells and an increase in the percentage of B-cells, CD8+ T-cells, and gamma delta T-cells during infection in both N'Dama and Boran was revealed by cytofluorimetric analysis of lymph node cells.

Immunopharmacology and cytokine production of a low-dose schedule of intraperitoneally administered human recombinant interleukin-2 in patients with advanced epithelial ovarian carcinoma

We determined in the peritoneal cavity (p.c.) of epithelial ovarian carcinoma patients during a 4-day treatment cycle of low-dose recombinant human interleukin-2 (rIL-2): (a) pharmacokinetics of IL-2, (b) endogenous cytokine production, and (c) numbers and percentages of peritoneal exudate lymphocytes. We administered 6 x 10(5) IU/m2 of rIL-2 (0.03 mg/m2 Proleukin rIL-2) intraperitoneally (i.p.) over 30 min on each of 4 days. One and one-half liters of D5 0.25 NS was injected i.p. before each rIL-2 infusion. Multiple peritoneal fluid samples were obtained from each of four patients on day 1 and day 4 for detection of IL-2, endogenous cytokines, and soluble IL-2 receptor (IL-2R-alpha). IL-2 concentrations in the peritoneal fluid were determined by bioassay and interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, IL-10, transforming growth factor (TGF)-beta 2, and sIL-2R-alpha by enzyme-linked immunosorbent assay. Numbers of cells per microliter and lymphocyte subpopulation percentages after staining with a panel of monoclonal antibodies were determined on day 1, day 4, and subsequent off-treatment days. IL-2 disappearance in the p.c. was well described by a pharmacokinetic model having constant-rate infusion and biexponential disposition. About 90% of the IL-2 disappearance occurred during the beta-phase, during which IL-2 concentrations were sustained at approximately 10-30 ng/ml (day 1 and day 4) and the median t1/2 beta was 21.5 and 9.2 h on days 1 and 4, respectively. In four of four patients, p.c. production of IL-10 was observed on day 1 and day 4 (maximum 387 pg/ml). Maximum levels of IFN-gamma and sIL-2R-alpha were observed on day 4. (IFN-gamma 217 pg/ml; sIL2-R-alpha: 3486 U/ml). No increases in TNF-alpha or TGF-beta 2 were observed. Large increases in p.c. CD3+, CD4+, CD8+, CD16+, and CD56+ cells were observed. We conclude that biologically active levels of IL-2 are generated in p.c. fluids after i.p. administration of rIL-2 at 0.03 mg/m2.

Lymphocytes subsets in normal individuals: analysis by four color immunofluorescence and flow cytometry on whole blood

In order to precisely define human lymphocytes subsets, we used four color immunofluorescence analysis and flow cytometry. We report here the results of systematic studies performed on whole blood from 20 normal volunteers. This was performed using monoclonal antibodies recognizing 18 different CD molecules and analyzed here into 14 different 4-color immunofluorescence combinations. This showed that among T cells, the two major CD3+CD8+ and CD3+CD8- subsets differed greatly in the percentage of cells expressing CD26, CD27, CD28, CD38, CD45RA, CD45RO, CD57, S6F1, BY55, CD101 and their respective combination representing an array of subsets. Furthermore the minor NK subsets, i.e. CD2+CD3-CD8+, CD2-CD3-CD8+, CD2+CD3-CD8-, CD2-CD3-CD8- also differed in percentages of cells expressing CD16, CD56, CD57, S6F1, BY55 and their combinations.

Identification of migratory graft and host cell populations after allogeneic rat small bowel transplantation

This study used flow cytometry to identify graft cells in the recipient peripheral blood and spleen and host cells infiltrating the graft mesenteric lymph node and Peyer's patches after heterotopic rat small bowel transplantation. Transplantation had little effect on the overall cell subset composition of these compartments and no changes appeared characteristic or indicative of developing rejection, suggesting that physiological control of cell migration remained unaltered. A small and transient population of graft cells was detected in the peripheral blood and spleen of the recipient which disappeared after 5 and 3 days respectively. Graft-derived cells in the peripheral blood comprised predominantly CD4+ cells on day 1 with B cells predominating on day 5. Graft cells infiltrating the spleen were predominantly B cells. Host cells infiltrated the graft mesenteric lymph nodes and Peyer's patches to a lesser extent than previously reported using immunohistochemical analysis. For both tissues, infiltrating host-derived cells initially comprised mainly CD4+ cells. On day 4 approximately equal proportions of CD4+ and B cells were present in the mesenteric lymph node, whereas B cells were predominant in the host cell infiltrate of the graft Peyer's patches. In summary, these findings indicate that the cell subset composition of recipient and graft lymphoid compartments does not change after small bowel transplantation, even in the presence of a substantial recipient cell infiltration. The reasons for the apparent discrepancies in the degree of host cell infiltration when assessed using immunohistochemical and flow cytometric techniques are currently uncertain, but may result from the localised release of soluble MHC class I in graft tissues as a consequence of infiltrating host cell activation or localised cell destruction.

Peripheral blood leukocyte populations in the elderly with and without periodontal disease

Periodontal disease in the elderly has not been characterized. Initial reports suggest that the disease is common and severe. Deficiencies in the immune response have also been reported to occur in the elderly. Consequently it was hypothesized that aging-related changes in the immune response may contribute to the severity and occurrence of periodontal disease in the elderly. To test that hypothesis, the % and number of leukocytes and leukocyte subsets in the peripheral blood of elderly (65-75 years) subjects were tested and used as indicators of the immune potential of those individuals. Age and gender effects on several of the parameters tested were identified. With the exception of increased number of leukocytes in the elderly group with severe periodontal disease, no other alteration in the leukocyte parameters tested were identified. These results suggest that periodontal disease in the elderly was not associated with obvious changes in the leukocyte and leukocyte subsets in the peripheral blood due to aging.

Papillon-Lefèvre syndrome. Analysis of peripheral blood lymphocyte subsets

We have studied the peripheral blood lymphocyte populations in our 6 patients (2 female and 4 male) with a mean age of 11.19 with Papillon-Lèfevre Syndrome (PLS) using adequate monoclonal antibodies and double coloured flow cytometry. Total B, T, CD4, CD8, CD29, CD45RA, NK, HLA-DR cells were studied. Total B, T, CD4 and CD8 lymphocytes were within normal limits. We have observed an increase in the CD29 lymphocytes and NK cells and a decrease in CD45RA lymphocytes. We think that these findings are important in explaining B lymphocyte activation and in the pathogenesis of the PLS.

A method for tracking the migration of blood lymphocytes

A method has been devised for labeling whole blood with the fluorescent dye fluorescein isothiocyanate (FITC) so the migration of blood lymphocytes can be studied in the sheep. Although lymphocytes can be purified from blood using density gradient media or elutriation it is difficult to obtain a large number of cells, because many cells are usually lost during the purification steps. It is desirable to label at least 10(8)-10(9) lymphocytes for lymphocyte tracking studies, because a smaller number is difficult to subsequently detect and quantitate in blood and lymph even using flow cytometry. Also, it is desirable to minimize the in vitro manipulation of lymphocytes, because dead or damaged lymphocytes will not recirculate. By labeling all the cellular components of a sample of whole blood rather than first purifying the lymphocytes we have been able to satisfy both of these criteria. Although labeled blood cells of all types are reinjected into the animal, the lymphocytes are easily distinguishable from other cells using a flow cytometer. In these studies between 2.4-12.4 x 10(8) lymphocytes were injected intravenously, and they were detectable in the blood and lymph for at least 10 days. The recovery of FITC-labeled (FITC+) lymphocytes in efferent lymph is comparable to that of lymphocytes labeled with other fluorescent or radioactive markers. The presence of labeled non-lymphoid cells in the animal makes this technique impractical for studies of lymphocyte localization within histologic sections. However, it is useful for studies in animals in which lymphatic vessels can be cannulated and the blood-to-lymph recirculation of labeled lymphocytes monitored, and it also may be applicable for studies in which lymphoid organ suspensions are analyzed using flow cytometry.

Alteration of peripheral blood lymphocyte subsets in essential hypertension

OBJECTIVE

To assess lymphocytic subpopulation by labelled monoclonal antibody technique in a small group of patients with untreated essential hypertension (EH) and to detect any alteration with control of blood pressure.

DESIGN

Prospective study with phenotypic estimation of lymphocytes at presentation and a minimum of two weeks after the control of blood pressure.

SETTING

Referral, tertiary care hospital.

PATIENTS

Group 1, normotensive controls (n = 10); group 2, mild to moderate essential hypertension (n = 10); group 3, severe (accelerated/malignant) hypertension (n = 10). All the secondary causes of hypertension were ruled out by a thorough history, physical examination and appropriate radiological and biochemical investigations.

TESTS

Venous blood samples, taken at entry and a minimum of two weeks after control of blood pressure, were analyzed by alkaline phosphatase antialkaline phosphatase (APAAP) antibody technique for CD4, CD3, CD8 and CD22. Peripheral lymphocytes were separated and cocultured with phytohemagglutinin (PHA) for 72 h and assayed for CD25 by the APAAP technique.

MAIN RESULTS

In untreated patients with EH (groups 2 and 3), there was a significant down regulation of CD3, and CD4 lymphocytes whereas the proportion of mature CD22 cells increased. In group 3 there was a significant down regulation of CD25 with PHA stimulation. A negative correlation was observed between CD25 and diastolic pressure upon pooling the results of groups 2 and 3. No significant alteration in these parameters was observed following control of blood pressure with drugs for up to two weeks.

CONCLUSION

In this small group of patients with untreated EH, a significant alteration in the lymphocytic repertoire was observed. Whether this will be found in large groups of hypertensives remains to be seen.

Establishing a pure lymphocyte gate for subset analysis by flow cytometry

Development of a more cost-effective and efficient method of performing lymphocyte subset analysis is of continuing importance in clinical flow cytometry laboratories. Current two-color methods utilize forward and right angle light scatter and multiple tubes per sample and are thereby liable to gate contamination. Methods using three-color analysis with CD45 vs. right angle light scatter (RALS) gating cannot always exclude a contaminating nonlymphoid population. We have established a two tube approach to directly measure total T cells, T suppressor, and T helper subsets, total B cells and total natural killer cells. The technique involves staining of whole blood with a mixture of five monoclonal antibodies conjugated to three fluorochromes: CD4+CD19 fluorescein isothiocyanate (FITC), CD3+CD33 phycoerythrin (PE), CD45 peridin chlorophyll alpha protein (PerCP), CD8+CD16 FITC, CD3+CD33 PE, and CD45 PerCP. Analysis is performed using a single laser flow cytometer. This method has equivalent recovery to and improved purity of the lymphocyte gate when compared to well-established methods. These antibody combinations additionally allow clear separation of lymphocytes from other leukocytes and debris as well as separation of the T cell helper and suppressor subsets, natural killer cells and B lymphocytes. We additionally provide preliminary data that an accurate lymphocyte subset analysis can be performed on a single tube containing five antibodies (CD4+CD19 FITC, CD3+CD33 PE, and CD45 PerCP), although some measurements are performed deductively.

Dynamic changes in the lymphocyte subpopulations of pig uterine lymph nodes

Cell subpopulations in local lymph nodes draining the uterine tissue of non-pregnant and pregnant pigs were examined by one- and two-colour immunofluorescent staining and flow cytometry using a panel of monoclonal antibodies to pig leucocyte cell surface antigens. Significant changes were observed in the T and B lymphocyte subpopulations and in a subpopulation of non-T or B cells. Activation of lymphocytes in the uterine lymph nodes during cycling in non-pregnant gilts suggests a role for the local immune system in the normal physiology of the uterus. In non-pregnant sows there was evidence of an increase in the CD4/CD8H ratio and in the proportion of B cells in the uterine nodes when compared to gilts with no prior reproductive experience. Pregnancy was shown to induce further dramatic changes in the uterine lymph nodes with an escalation in the proportion of B cells from 48% to 88% and a further increase in the CD4/CD8H ratio. For the first time in swine, low-level CD2 expression is reported on a subpopulation of B cells which are activated during pregnancy. These results provide evidence that the local uterine immune system in pigs plays a role in reproduction and perhaps in the maintenance of normal pregnancy.

Immunophenotypic profiles of peripheral blood lymphocytes in women with recurrent pregnancy losses and in infertile women with multiple failed in vitro fertilization cycles

In summary (1) Nonpregnant women with RSAs of unknown etiology have higher levels of CD56+ lymphocytes when compared to normal controls; (2) The levels of CD19+, CD56+, and CD56+/CD16+ PBL of pregnant women with RSA are significantly higher than those of multiparous pregnant normal controls; (3) Women with autoantibodies to phospholipids have significantly higher levels of elevated CD56+ and CD56+/CD16+ lymphocytes when compared to women without antiphospholipid antibodies; (4) Women with autoantibodies to nuclear components demonstrate higher numbers of CD19+/CD5+ cells compared to women without autoantibodies to nuclear components; (5) Idiopathic infertile women with multiple prior IVF failures demonstrate significantly higher levels of CD56+ pBL than normal fertile controls and the conception rate is much higher in those with CD56+ levels less than 12%; (6) Elevations of CD56+ lymphocytes to over 18% during a pregnancy is a good prognostic indicator of impending pregnancy loss. We have not seen a liveborn infant in women with levels of 18% or higher without IVIg therapy; and (7) Infertile and RSA women who fail alloimmune and autoimmune therapy have significant alterations in cellular and humoral immunity involving NK cells and CD19+/CD5+ B cells.

Decreased production of IFN gamma and increased production of IL-6 by cord blood mononuclear cells of newborns with a high risk of allergy

BACKGROUND

The underlying mechanisms of elevated IgE level in atopic patients are still obscure, however, extensive efforts have been tried to identify an immunological parameter as a predictor of atopy.

OBJECTIVE

This study compared the difference in cytokine production by cord blood mononuclear cells between new borns with high-risk of allergy (family allergy score, FAS > or = 3) and those with low-risk (FAS = 0).

METHODS

Following stimulation with PHA (100 micrograms/mL) and PMA (1 ng/mL), the cytokines produced by cord blood CD4+ T cells in the presence of monocytes were measured by ELISA kits and the mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR) technique.

RESULTS

Our results showed: CD4+ T cells in the presence of monocytes and isolated monocytes from the high-risk group produced a much greater amount of IL-6, either spontaneously or after stimulation, than did those of the low-risk group; CD4+ T cells of low-risk group produced a significantly greater amount of interferon gamma (IFN gamma) than did those from the high-risk group; IL-4 cannot be detected by ELISA kit, and only a trace amount of IL-4 mRNA was detected by RT-PCR technique; cord blood basophils stimulated with PHA and PMA could produce a significant amount of IL-4; there was an inverse correlation between the production of IFN gamma and cord blood IgE level (high-risk group, r = 0.647, n = 17) and the number of natural killer (NK) cells (CD3- CD16+ CD56+) was significantly lower in high-risk group than for low-risk group.

CONCLUSION

Our data suggested increased production of IL-6 and decreased production of IFN gamma of cord blood mononuclear cells appear to be the hallmark of newborns from the high-risk population.

Trypanosoma congolense infection in sheep: cellular phenotypes in lymph and lymph nodes associated with skin reactions

Intradermal inoculation of sheep with culture-derived metacyclic forms of Trypanosoma congolense resulted in the development of localized skin reactions (chancres) and enlargement of the draining lymph nodes 7 days after infection. Changes in the expression of surface antigens of lymphocytes in lymph leaving the affected skin reactions and in the associated lymph nodes were monitored by cannulating the afferent and efferent lymphatic ducts. Trypanosomes appeared in afferent and efferent lymph 3 to 5 days after infection and persisted even as the chancres regressed. The cellular output in both afferent and efferent lymph increased markedly after the onset of parasitosis. Sequential analysis of the phenotypes of lymphocytes by immunofluorescent staining and flow cytometry revealed that in afferent lymph draining the chancre there was an early response which was due to an increase in T cells, particularly CD4+ and CD8+ cells; however, as the chancres-regressed there was an increase in lymphoblasts and surface immunoglobulin-bearing cells. In contrast, in the efferent lymph, the increase in lymphocytes was due predominantly to a higher number of cells bearing surface immunoglobulins.

[The immunological phenotyping of the lymphocytes in HIV+ patients]

We propose that the ratios of lymphocyte subsets: CD4+/CD8+, CD4+/CD3+, and CD8+/CD3+, graphically displayed in this order, could be an easy way of immunophenotyping and a simple form of interpretation both for clinicians and patients. A total of 187 asymptomatic HIV-positive patients, -including 83 symptomatic patients with AIDS- and a normal comparative age group of 36 patients, were studied by flow cytometry. Ratios were graphically displayed on millimetric-grid paper, and a specific point was given to each obtained ratio. The points were connected by a line. The angles formed by the lines were measured and graphically displayed over a circle. The point of reference 0 degree was located on the left side of the circle, giving the corresponding 90 degrees, 180 degrees, and 240 degrees angles. The graph of the control group shows a "beach chair" image. As soon as the CD4+ lymphocytes diminish and the CD8+ lymphocytes increase in HIV+ patients, "the chair's headrest" descends and the "chair's footpiece" swivels back. Given the ranks and fluctuations of the lymphocyte subsets, their graphic display provides a better representation of the immunological status.

Normal uterine cervix: characterization of isolated lymphocyte phenotypes and immunoglobulin secretion

PROBLEM

Isolation of viable cervical lymphocyte populations and characterization of their function in healthy tissue is necessary to understand immunity in the genital tract.

METHODS

Normal, cervical tissue was digested using a multi-enzymatic digestion procedure. Lymphocytes were characterized using FACS analysis and ELISPOT analysis for immunoglobulin secreting cells.

RESULTS

Following the digestion procedure, 0.16 x 10(6) +/- 0.8 cells/g of tissue with a viability of 90-98% were isolated from normal cervical tissue. FACS analysis determined that B lymphocytes were the predominant cell type in normal cervical tissue representing a significantly higher percentage than that found in peripheral blood (P = 0.015). T lymphocytes and NK cells represented a significantly lower percentage than that found in peripheral blood (P = 0.0001 and 0.026, respectively). The largest percentage of immunoglobulin secreting cells isolated were secreting IgG followed by IgA. A limited number of IgM secreting cells were detected. IgA2 secreting cells represented 34.46 +/- 4.6% of the total number of IgA plasma cells.

CONCLUSION

These studies represent the first analysis of viable mononuclear cells isolated from normal cervical tissue. The results form a baseline from which it will now be possible to compare changes that occur at the cervical squamocolumnar junction in response to infection or neoplasia.

Analysis of feline dual lymphocyte populations observed by flow cytometry

Two discrete lymphocyte populations were observed commonly on flow cytometric analysis (FCM) of feline lymphocyte subsets. The identity of these populations as small and large lymphocytes was established by correlating data from FCM with that from peripheral blood films. Dual lymphocyte populations were more likely to be seen in feline immunodeficiency virus-positive (FIV(-)+ ve) cats but their occurrence was not affected by health status, age, gender or breed. FIV(-)+ ve cats had a significantly higher proportion of large lymphocytes than FIV-negative (FIV(-)- ve) cats. However, FIV(-)+ ve cats had significantly fewer small lymphocytes than FIV(-)- ve cats but similar numbers of large lymphocytes. Lymphocyte subset analysis revealed that small lymphocytes had a greater proportion of CD4+ cells than large lymphocytes, regardless of the FIV or health status of the cat. In FIV(-)- ve cats, small lymphocytes had a greater proportion of Pan T + lymphocytes than large lymphocytes, but the converse was seen in FIV(-)+ ve cats. The proportion of CD8 + cells was higher in small lymphocytes than large lymphocytes in well FIV(-)- ve cats but this distinction was not seen in sick FIV(-)- ve cats or FIV(-)+ ve cats of any health status. Regardless of health status, FIV(-)+ ve cats had a lower absolute count of small lymphocytes which were T cells (due to lower numbers of both CD4 + and CD8 + cells) than FIV(-)- ve cats. The numbers of small B cells were similar for both FIV(-)+ ve and FIV(-)- ve cats. However, there were no differences between FIV(-)+ ve and FIV(-)- ve cats in the absolute values of any subset of the large lymphocytes, which suggested that FIV may affect only small lymphocytes. Statistically, the inclusion or exclusion of the large lymphocyte population for routine lymphocyte subset analysis did not affect the overall results. However, because there were significant differences in subset distribution between small and large lymphocytes, analysis of both groups should be included in studies examining the role of lymphocytes in disease.

Immunological effects of the anti-IL-2 receptor monoclonal antibody BT 563 in liver allografted patients

The immunological effects of therapeutic monoclonal antibodies (mAbs) depend upon their interaction with the target structure as well as the isotype of the mAb which is responsible for the binding to Fc receptors of accessory cells. The aim of the presented analysis was the evaluation of the in vivo immunosuppressive effect of BT 563, a mAb directed to the alpha-chain of the interleukin-2 receptor (IL-2R). Thirty-eight patients following liver transplantation were treated prophylactically for 12 days with 10 mg/day BT 563 (clinical phase II and III study). As baseline immunosuppression cyclosporin (CyA) and low dose steroids were administered. BT 563 levels, lymphocyte subpopulations, levels of soluble CD25 and Fc receptor polymorphism were evaluated and compared to the clinical outcome. Preoperatively in all patients a small subset of CD45R0+ cells expressed CD25 with detectable density. These cells were coated by BT 563. There was no evidence for depletion of IL-2R+ cells or modulation of the IL-2R. During therapy stable levels of the soluble IL-2R were measured in patient sera. Throughout the therapy high levels of unbound BT 563 were found in sera, suggesting that IL-2R newly expressed on cells activated by the allograft could also be inhibited by BT 563. No acute rejections were observed in these patients and no side effects of BT 563 were noted. There were only minor bacterial infections, while mycotic or viral infections did not appear. Administration of BT 563 together with CyA and low dose steroids to liver allografted patients represents a safe and effective protocol. Its action is likely to be mediated by turning off the pathway of signal transduction of the IL-2R in T-cells by the antibody while IL-2 gene transcription is simultaneously modified by CyA and steroids. The addition of all three immunosuppressive mechanisms is suggested to lead to a state of anergy during mAb application that is reversible at the end of antibody therapy but does not lead to rebound rejections. Analysis of the phenotype of CD25+ cells showed that they preferentially belonged to the CD45R0+ cell type. Thus we assume that BT 563 specifically turns off preactivated cells enabling rather selective and effective immunoprophylaxis in liver allografted patients.

Immune responsiveness of Romney sheep selected for resistance or susceptibility to gastrointestinal nematodes: field studies

Long-term selection of sheep for resistance to parasite infections may be jeopardized if animals do not retain their normal ability to respond to non-parasite antigens. Therefore the antibody responses to ovalbumin (OVA) and human red blood cells (HRBC), and kinetics of peripheral blood lymphocyte phenotypes were examined in mature grazing sheep, genetically resistant or susceptible to gastrointestinal nematodes. In both lines the HRBC antibody response peaked 2 weeks after the primary injection, 1 week after the second injection and 3 weeks after the second OVA injection. The antibody titres of the resistant line sheep decreased sooner after both primary and secondary injections. The resistant line sheep had higher percentages of CD5+ and CD4+ cells than the susceptible sheep. Two injections of OVA and HRBC did not result in significant alterations in percentages of CD5+, CD4+, CD8+ and CD45R+ lymphocytes in either line. In both lines, the control groups showed a steady increase of 0.29% per week in percentages of T19+ (gamma delta) T cells which was significantly higher than in the antigen injected sheep.

Up-regulation of IL-2 receptor alpha and MHC class II expression on lymphocyte subpopulations from bovine leukemia virus infected lymphocytotic cows

Infection with bovine leukemia virus (BLV) leads to a persistent lymphocytosis (PL) characterized by a marked increase in circulating B lymphocytes that express the orthologue of CD5. To gain insight into the factors accounting for lymphocytosis, experiments were conducted to determine the functional activation status of lymphocytes from BLV seronegative and BLV infected aleukemic cows with PL. Stimulation with the B lymphocyte mitogen Staphylococcus aureus Cowan strain I (SAC), recombinant human interleukin-2 (rIL-2), or pokeweed mitogen (PWM), a T lymphocyte-dependent B lymphocyte mitogen, revealed differences in the pattern of expression of IL-2 receptor alpha (IL-2R alpha) and major histocompatibility (MHC) class II molecules on B and T lymphocytes from uninfected and BLV infected PL cows. rIL-2 induced expression of IL-R alpha on B lymphocytes from PL cows but not B lymphocytes from BLV seronegative cows. SAC alone, or in combination with rIL-2, had no effect on B lymphocytes from BLV seronegative cows. However, rIL-2 alone or in combination with SAC induced expression of IL-2R alpha on B lymphocytes from PL cows. PWM stimulated expression of IL-2R alpha on bovine B lymphocytes regardless of BLV status, and induced a significantly higher level of expression on B lymphocytes from PL cows. Mitogens and rIL-2 had a similar stimulatory effect on induction of IL-2R alpha expression on CD4 T lymphocytes regardless of BLV status. Only PWM induced expression of IL-2R alpha on bovine CD8 T lymphocytes and induced a significantly higher level of expression on this T lymphocyte subset from PL cows. Examination of freshly isolated B lymphocytes from PL cows revealed increased spontaneous expression of the MHC class II molecule compared to B lymphocytes from control cows. None of the culture conditions examined induced MHC-II expression on CD4 and CD8 T lymphocytes from BLV seronegative cows. In contrast, SAC+IL-2 and PWM induced MHC-II expression on CD4 and CD8 T lymphocytes from BLV infected PL cows, resulting in a significantly greater proportions of these lymphocyte subsets expressing this molecule compared to CD4 and CD8 T lymphocytes from control cows. The data indicate that infection with BLV affects the response of B and T lymphocytes to signals of activation, up-regulating the expression of surface molecules involved in both direct contact and cytokine-mediated T lymphocyte-dependent B lymphocyte activation.

The effect of storage on immunophenotyping of sheep peripheral blood lymphocytes by flow cytometry

We have shown that when a whole blood method of cell staining is used for flow cytometric analysis of sheep lymphocytes (i.e. red cell lysis after addition of antibody), staining may be delayed for up to 48 h after blood collection without significant effect on expression of CD4, CD5, CD8 or B cell markers. If cells were stained immediately after blood collection, using the same whole blood method, and then fixed with paraformaldehyde, cell samples could be stored for 24 h without change in marker expression. However, by 7 days there was a significant decrease in the percentage of cells expressing CD8, T19 and B cell markers. Cryopreservation prior to staining was found to markedly affect the expression of all cell surface markers investigated. These results indicate that storage of sheep blood prior to flow cytometric analysis is feasible but may affect the results obtained. Thus is it important to standardise the handling of samples, especially when comparative studies are being undertaken.

Distribution and lytic activity of NK cell subsets in the elderly

Old subjects present an increased number of NK cells associated with a decreased lytic activity of isolated and cloned CD16 cells. Recently, two new surface molecules of 58 kDa, identified by the monoclonal antibodies GL183 and EB6, have been described. The presence of these molecules, which can be coexpressed on CD16+ cells allows the recognition of the NK cell subsets whose cytolytic activity is restricted to different allospecificities. This study investigated a group of old subjects to determine whether a particular distribution or a different lytic activity of NK subsets, defined by MoAbs GL183 and EB6, is involved in the altered cytolytic activity found during ageing. Further, we investigated whether the ageing process might be responsible for a restriction of the NK cell repertoire involved in the recognition of allogenic cells. We found that old and young subjects have a similar proportion of double positive and double negative GL183/EB6 cells, while in the old group single positive subsets were increased. The lytic activity of sorted NK subsets isolated from old and young subjects was similar, although double positive and double negative cells from the old presented a lower cytotoxic activity. The addition of IFN-beta or rIL-2 to the culture medium restored the lytic activity to the level found in young subjects. These data show that the decreased NK lytic activity found in the old subjects is shared out among the different NK subsets and normal aged subjects do not lose the NK repertoire found in the young.

In vitro studies of cytokine-mediated interactions between malignant glioma and autologous peripheral blood mononuclear cells

The humoral interactions between three malignant glioma early-passage cell cultures and in vitro interleukin (IL)-1 alpha- and IL-2-activated autologous peripheral blood mononuclear cells (PBMC's) were investigated, employing standard and modified (separated by permeable membranes) mixed lymphocyte tumor cell (MLTC) cultures. In modified MLTC's, glioma cells clearly inhibit proliferation of PBMC's (up to 60%), whereas lymphokine-activated PBMC's enhance glioma cell growth up to 12-fold, as determined by 3H-thymidine incorporation assays. Glioma cells produce both stimulatory (IL-6) and inhibitory proteins (transforming growth factor-beta) for PBMC's. Lymphokine-activated PBMC's secrete IL-1 alpha, IL-2, IL-4, IL-6, interferon-gamma, and tumor necrosis factor-alpha, which may modulate glioma cell proliferation. None of these cytokines stimulated glioma cells as intensely as modified MLTC systems. These observations indicate that in vitro lymphokine-activated PBMC's, although suppressed by humoral glioma-derived factors, may enhance glioma cell proliferation with soluble factors secreted into the culture medium. The authors conclude that glioma-lymphocyte growth regulatory networks include stimulatory and inhibitory factors from both cell populations, which may modulate tumor progression. These observations may have relevance for adoptive immunotherapy in patients with gliomas.

Flow cytometric analysis of peripheral blood lymphocyte immunophenotypes in persons infected with Treponema pallidum

To characterize the human immune response to syphilis, we determined the effect of infection with Treponema pallidum on the percentage of the various lymphocyte subpopulations in the peripheral blood of infected and uninfected persons. Monoclonal antibodies labeled with either fluorescein isothiocyanate or phycoerythrin were used to perform dual color analysis on a FACScan with the following markers: CD3 for total T cells, CD4 for T helper cells, CD8 for T suppressor cells, CD19 for B cells, and CD16 plus CD56 for natural killer cells. Lymphocyte immunophenotype results were analyzed by the stage of untreated syphilis and by gender. Although they were within the ranges of the normal distribution of immunophenotypes, the percentages of CD4+ cells were significantly lower (P < 0.001) and those of CD8+ cells were higher (P = 0.03) in patients with syphilis than in the uninfected population. For infected versus uninfected subjects, both women and men, the differences in the mean percentages of CD3+ and CD4+ cells were significant (P < or = 0.05). Significant differences were noted between the sexes in secondary syphilis only in the mean percentages of cells positive for CD3, CD4, CD8, and CD16 plus CD56. Gender had no effect on lymphocyte subpopulations in subjects with primary or latent syphilis. In the control population, significant differences due to gender were observed in the percentages of cells positive for CD3, CD4, and CD16 plus CD56.