Proportion Of Peripheral Blood Lymphocytes Research Articles

Negative serum (1,3) -β-D-glucan has a low power to exclude Pneumocystis jirovecii pneumonia (PJP) in HIV-uninfected patients with positive qPCR

ObjectiveThe current study evaluated the diagnostic performance of serum (1,3)-beta-D Glucan (BDG) in differentiating PJP from P. jirovecii-colonization in HIV-uninfected patients with P. jirovecii PCR-positive results.MethodsThis was a single-center retrospective study between 2019 and 2021. The diagnosis of PJP was based on the following criteria: detection of P. jirovecii in sputum or BAL specimen by qPCR or microscopy; Meet at least two of the three criteria: (1) have respiratory symptoms of cough and/or dyspnea, hypoxia; (2) typical radiological picture findings; (3) receiving a complete PJP treatment. After exclusion, the participants were divided into derivation and validation cohorts. The derivation cohort defined the cut-off value of serum BDG. Then, it was verified using the validation cohort.ResultsTwo hundred and thirteen HIV-uninfected patients were enrolled, with 159 PJP and 54 P. jirovecii-colonized patients. BDG had outstanding specificity, LR, and PPV for PJP in both the derivation (90.00%, 8.900, and 96.43%) and the validation (91.67%, 9.176, and 96.30%) cohorts at ≥ 117.7 pg/mL. However, it had lower sensitivity and NPV in the derivation cohort (89.01% and 72.97%), which was even lower in the validation cohort (76.47% and 57.89%). Of note, BDG ≥ 117.7 pg/mL has insufficient diagnostic efficacy for PJP in patients with lung cancer, interstitial lung disease (ILD) and nephrotic syndrome. And although lymphocytes, B cells, and CD4+ T cells in PJP patients were significantly lower than those in P. jirovecii-colonized patients, the number and proportion of peripheral blood lymphocytes did not affect the diagnostic efficacy of serum BDG.ConclusionsSerum BDG ≥ 117.7 pg/mL could effectively distinguish P. jirovecii-colonization from infection in qPCR-positive HIV-uninfected patients with infectious diseases, solid tumors (excluding lung cancer), autoimmune or inflammatory disorders, and hematological malignancies. Of note, for patients with lung cancer, ILD, and nephrotic diseases, PJP should be cautiously excluded at BDG < 117.7 pg/mL.

Immunomodulatory Effects of Microcin C7 in Cyclophosphamide-Induced Immunosuppressed Mice.

Microcin C7 (McC) as a viable immunomodulator peptide can be a potential solution for pathogenic microbial infection in the post-antibiotic era and has gained substantial attention. This study was designed to evaluate the immunomodulatory activity of Microcin C7 in a cyclophosphamide (CTX)-induced immunodeficient mouse model. We show that Microcin C7 treatment significantly alleviated the CTX-caused body weight loss, improved the feed and water consumption to improve the state of the mice, and elevated the absolute number and proportion of peripheral blood lymphocytes as well as the level of hemoglobulin. We further aim to characterize the phenotypes of the immune function and intestinal health profiles. The results demonstrate that Microcin C7 treatment increased serum levels of immunoglobulin A (IgA), IgG, interleukin 6, and hemolysin, promoted splenic lymphocyte proliferation induced by concanavalin A and LPS, and enhanced the phagocytosis of peritoneal macrophages immunized by sheep red blood cells. Additionally, Microcin C7 treatment decreased levels of diamine oxidase and d-lactate, ameliorated CTX-induced intestinal morphological damage, and increased the levels of zonula occluden 1, occludin, claudin-1, mucin 2, and secretary IgA in the jejunum and colon. Moreover, Microcin C7 administration is sufficient to reverse CTX-induced intestinal microbiota dysbiosis by increasing the number of Lactobacillus and Bifidobacterium, decreasing the number of Escherichia coli in colonic contents. Collectively, our results demonstrate that Microcin C7 may have protective and immunomodulatory functions and could be a potential candidate used in animal feed, functional foods, and immunological regimens..

The Flow Cytometric Analysis of Peripheral Blood Lymphocytes and Expression of HLA II Molecules in Lymphocyte During Acute Rejection After Renal Transplantation.

To investigate the changes in the proportion of peripheral blood lymphocytes and the expression of HLA II molecules in lymphocytes during acute rejection after renal transplantation. Thirty-five patients who had undergone renal transplantation were selected. Eighteen patients with clinical and pathological confirmed acute rejection were selected as the test group, and twelve patients without clinical acute rejection symptoms were selected as the control group. Flow cytometry analysis was used to determine the proportion of peripheral blood lymphocytes. The mRNA and protein expression of HLA II molecules on peripheral blood lymphocytes were detected using real-time fluorescence quantification and immunoblotting, respectively. The proportion of T lymphocytes, B lymphocytes, and CD4CD8 double positive T cells in the Control Group were 67.48% ± 5.35%, 10.82% ± 1.26%, and 0.88% ± 0.06%, respectively, and in the Test Group were 87.52% ± 6.28%, 3.36% ± 0.26%, and 0.34% ± 0.03%, with a significant difference respectively. The mRNA and protein expressions of HLA II molecules of peripheral blood B lymphocytes in the control group were significantly higher that these in the test group. The proportion of peripheral blood T lymphocytes, B lymphocytes, CD4CD8 double positive T cells, and the expression of HLA II molecules of peripheral blood lymphocytes can all indicate the occurrence of acute renal transplantation rejection, which were exceedingly useful to clinicians in judging the acute rejection of renal transplantation in the early stages.

Ginseng-containing traditional medicine preparations in combination with fluoropyrimidine-based chemotherapy for advanced gastric cancer: A systematic review and meta-analysis.

Ginseng-containing traditional medicine preparations (G-TMPs) in combination with fluoropyrimidine-based chemotherapy (FBC) are well-known treatments for advanced gastric cancer (AGC), with a superior efficacy to FBC alone. However, evidence regarding their efficacy remains limited. The purpose of this meta-analysis is to evaluate the efficacy and safety of G-TMPs in combination with FBC for the treatment of AGC. Eight electronic databases were searched for randomized controlled trials (RCTs) using G-TMPs with FBC for the treatment of AGC. The primary outcome included the tumor response, while the secondary outcomes included the quality of life (QoL), proportions of peripheral blood lymphocytes, adverse drug reactions (ADRs), and levels of cancer biomarkers. The quality of evidence for each outcome was assessed using GRADE profilers. A total of 1,960 participants were involved in the 26 RCTs included. Patients treated with FBC plus G-TMPs had better objective response (risk ratio [RR] = 1.23, 95% confidence interval [CI]: 1.13 to 1.35, p < 0.00001) and disease control (RR = 1.13, 95% CI: 1.08 to 1.19, p < 0.00001) rates than those treated with FBC alone. Additionally, the combination group had a better QoL, higher proportions of CD3+ T cells, CD4+ T cells, and natural killer cells, as well as a higher CD4+/CD8+ T-cell ratio. Furthermore, lower levels of CA19-9, CA72-4, and CEA were confirmed in the combination treatment group. In addition, G-TMPs reduced the incidence of ADRs during chemotherapy. In combination with FBC, G-TMPs can potentially enhance efficacy, reduce ADRs, and improve prognosis for patients with AGC. However, high-quality randomized studies remain warranted. PROSPERO Number: CRD42021264938.

Abstract 5662: Targeting N-myristoylation for therapy of adult acute myeloid leukemia

Abstract Two N-myristoyltransferases (NMTs) NMT1 and NMT2 catalyze the reaction. NMT1 is ubiquitous expressed and is essential for cell survival while NMT2 is more variably expressed and non-essential suggesting that their substrate specificity and activity levels differ. Historically, inhibition of myristoylation was suggested as a therapeutic anti-cancer target since NMTs expression were shown to be increased in numerous types of cancers and myristoylation was shown to be essential for proper localization and activity of some important proto-oncogenes such as Src Family Kinases (SFKs). Recently, we showed NMT2 expression is lost in numerous haematological cancer cell lines (including AML) and that these haematological cancer cell lines are exquisitely sensitive to the pan-NMT inhibitor PCLX-001. PCLX-001 recently entered human clinical trials as once daily oral therapy for relapsed/refractory B-cell Non-Hodgkin Lymphoma and advanced solid malignances. Dysregulation and oncogenic activity of SFKs occurs frequently in AML, suggesting NMT inhibition could provide therapeutic benefit in this indication. Data analysis from the TCGA transcriptome database revealed that high NMT1 and low NMT2 were associated with reduced overall and event-free survival in adult AML. Moreover, high NMT1 - but not NMT2 - expression is associated with proliferative gene sets in AML cell lines. AML cell lines treated with PCLX-001 showed a significant reduction in total protein myristoylation, reduced levels of SFK proteins and SFK phosphorylation as well as significant increases in ER stress marker BIP protein and caspase 3 cleavage. PCLX-001 induced apoptosis in AML cell lines and patient blasts at concentrations that spared a large proportion of peripheral blood lymphocytes and monocytes from healthy individuals. PCLX-001 monotherapy had dose-dependent anticancer activity in an AML MV-4-11 cell line derived xenograft (CDX) and two AML patient derived xenografts (PDXs) and produced complete remissions in subcutaneous AML CDX. In tail-vein injected PDX models, PCLX-001 treatment resulted in up to 95% reduction of human CD45+ cells in peripheral blood and bone marrow. PCLX-001 preferentially targeted AML cells inducing apoptosis and reducing leukemic burden. These findings validate NMT inhibition as a novel therapeutic strategy for AML and warrant the evaluation of PCLX-001 in clinical trials for adult AML. Citation Format: Jay Gamma, Aishwarya Iyer, Megan Yap, Zoulika Zak, Krista Vincent, Cassidy Ekstrom, Qiang Liu, Erwan Beauchamp, Lynne Postovit, Jean Wang, John R. Mackey, Naveen Pemmaraju, Gautam Borthakur, Joseph Brandwein, Luc Berthiaume. Targeting N-myristoylation for therapy of adult acute myeloid leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5662.

Validation of NMT1 and NMT2 As Novel Drug Targets in Adult Acute Myeloid Leukemia: Rationale for N-Myristoyltransferase Inhibition with Pclx-001 for Clinical Trials

Background: N-terminal myristoylation is the transfer of the saturated fourteen carbon fatty acid myristate to an N-terminal glycine residue. This co- or post-translational protein modification promotes protein-protein and protein-lipid interactions and is essential for proper membrane localization and/or activity of up to 600 human intracellular proteins. N-myristoyltransferases (NMTs) are the enzymes responsible and two isoforms are found in humans. NMT1 (ubiquitous and essential for cell survival) and NMT2 (more variably expressed) differ in activity level and substrate specificities. NMT expression levels vary in some cancers, and with myristoylation being essential for activity of certain oncogenes including Src Family Kinases (SFKs). NMTs have therefore been proposed as an anti-cancer target. Dysregulation and oncogenic activity of SFKs occurs frequently in acute myeloid leukemia (AML), suggesting NMT inhibition could provide therapeutic benefit. PCLX-001 is a low nanomolar small molecule pan-NMT inhibitor with high oral bioavailability in clinical trials as once daily oral therapy for lymphoma and solid tumors.Methods and Results: Data from the TCGA Transcriptome database showed high NMT1 and low NMT2 were associated with reduced overall and event-free survival in adult AML, and high NMT1 - but not NMT2 - expression is associated with proliferative gene sets in AML cell lines. AML cell lines treated with PCLX-001 showed a significant reduction in total protein myristoylation, as well as reduced levels of SFK proteins and SFK phosphorylation. PCLX-001 induced apoptosis in AML cell lines and patient blasts at concentrations which spared a large proportion of peripheral blood lymphocytes and monocytes from healthy individuals. AML cell lines showed significant increase in BIP protein and ER stress in response to PCLX-001, along with caspase 3 cleavage. In an AML cell line derived xenograft (CDX) and two AML patient derived xenograft (PDX) series (n=1 DX for MV-4-11 and n=2 PDX), PCLX-001 monotherapy had dose-dependent anticancer activity and resulted in complete remissions in subcutaneous AML cell deposits. In tail-vein injection PDX models, PCLX-001 treatment resulted in up to 95% reduction of human CD45+ cells in peripheral blood and bone marrow.Conclusions: These findings validate NMT inhibition as a novel therapeutic strategy for AML. PCLX-001 preferentially targeted AML cells that rely on oncogenic activity of myristoylated proteins, inducing apoptosis and reducing leukemic burden. PCLX-001 warrants evaluation in clinical trials for adult AML. DisclosuresGamma: Pacylex Pharmaceuticals: Current holder of individual stocks in a privately-held company. Yap: Pacylex Pharmaceuticals: Current holder of individual stocks in a privately-held company, Patents & Royalties. Beauchamp: Pacylex Pharmaceuticals: Current Employment, Current holder of individual stocks in a privately-held company, Patents & Royalties. Mackey: Pacylex Pharmaceuticals, Inc.: Current holder of individual stocks in a privately-held company. Pemmaraju: Dan's House of Hope: Membership on an entity's Board of Directors or advisory committees; Abbvie Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other, Research Funding; Aptitude Health: Consultancy; Sager Strong Foundation: Other; Celgene Corporation: Consultancy; LFB Biotechnologies: Consultancy; Plexxicon: Other, Research Funding; MustangBio: Consultancy, Other; Roche Diagnostics: Consultancy; Daiichi Sankyo, Inc.: Other, Research Funding; DAVA Oncology: Consultancy; Cellectis S.A. ADR: Other, Research Funding; Springer Science + Business Media: Other; Stemline Therapeutics, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other, Research Funding; HemOnc Times/Oncology Times: Membership on an entity's Board of Directors or advisory committees; ASCO Leukemia Advisory Panel: Membership on an entity's Board of Directors or advisory committees; Samus: Other, Research Funding; ASH Communications Committee: Membership on an entity's Board of Directors or advisory committees; CareDx, Inc.: Consultancy; Novartis Pharmaceuticals: Consultancy, Other: Research Support, Research Funding; Incyte: Consultancy; Affymetrix: Consultancy, Research Funding; Protagonist Therapeutics, Inc.: Consultancy; Clearview Healthcare Partners: Consultancy; Blueprint Medicines: Consultancy; Bristol-Myers Squibb Co.: Consultancy; ImmunoGen, Inc: Consultancy; Pacylex Pharmaceuticals: Consultancy. Borthakur: Astex: Research Funding; Ryvu: Research Funding; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Protagonist: Consultancy; ArgenX: Membership on an entity's Board of Directors or advisory committees; University of Texas MD Anderson Cancer Center: Current Employment; Takeda: Membership on an entity's Board of Directors or advisory committees; GSK: Consultancy. Brandwein: AbbVie: Honoraria; Jazz: Honoraria; Taiho: Honoraria; Astellas: Honoraria; Bristol Myers Squibb: Honoraria; Roche: Honoraria; Pfizer: Honoraria; Amgen: Honoraria. Berthiaume: Pacylex Pharmaceuticals, Inc.: Current holder of individual stocks in a privately-held company.

Application of Peripheral Blood Lymphocyte Count in Prediction of the Presence of Atypical Lymphocytes

Atypical lymphocytes (AL), or reactive lymphocyte, exist in peripheral blood when stimulated by viral infection, drugs, inflammatory signals or allergens. Studies have shown that specific changes in peripheral blood (PB) analysis can predict morphological changes in blood cells. The objective of this study was to explore the value of the peripheral blood lymphocyte count in predicting the presence of AL. One hundred ninety-nine outpatients were selected from Beijing Chao-Yang Hospital, Capital Medical University from January to April 2015 and underwent manual cell classification with evaluation of complete clinical data. The results of manual classification of peripheral blood leukocytes and peripheral blood routine analysis were assessed, and the correlation between peripheral blood lymphocyte counts and presence of atypical lympho-cytes evaluated using receiver operating characteristic (ROC) curves for each subject. Peripheral blood lymphocytes ≥ 2.375 x 109/L was found to be the optimal cutoff point for predicting atypical lymphocytes. The area under the curve (AUC), 95% confidence interval (CI), sensitivity and specificity were 0.7984, 0.7121 - 0.8846, 68.42%, and 82.8%, respectively, while the accuracy was moderate. When the proportion of peripheral blood lymphocytes was greater than 35.90%, the AUC, 95% CI, sensitivity, and specificity were 0.8729, 0.8092 - 0.9366, 89.47%, and 76.34%, respectively, while the accuracy was moderate. The peripheral blood lymphocyte count of a patient has good predictive value for the existence of atypical lymphocytes, which is helpful for clinical diagnosis.

Plasticity and Overlap of In Vitro–Induced Regulatory T-Cell Markers in Healthy Humans

Induced regulatory T cells (iTreg) are a heterogeneous T-cell subset that is induced during an allo-response and down-regulates the immune response. iTreg are commonly characterized as CD4+CD25high, CD4+CD25highFoxP3+, CD4+CD25highCD127−, or CD4+CD25highFoxP3+CD127− peripheral blood lymphocytes (PBL). In the present study, we investigated the overlap of these 4 phenotypically determined iTreg subsets in normal human individuals. PBL of 8 healthy individuals were incubated for 0 hours (Group 1) or for 16 hours in medium without (Group 2) or with phorbol 12-myristate 13-acetate (PMA)/Ionomycin (Group 3). Thereafter, proportions of PBL with Treg phenotypes were determined using 4-color flow-cytometry. All 4 Treg subsets increased strongly during polyclonal stimulation (P < .001). After stimulation, combining 2 iTreg markers, 24% of stimulated CD4+ PBL were CD25highFoxP3+, 18% CD25highCD127−, and 61% FoxP3+CD127−. Combining 3 iTreg markers, only 18% of the polyclonally stimulated CD4+ PBL were CD25highFoxP3+CD127−. Importantly, the proportion of FoxP3+CD127− PBL increased with the quantity of CD25 on stimulated CD4+ PBL and was highest in CD25high PBL (P = .002), emphasizing the relevance of CD25high as iTreg marker. Different iTreg phenotypes should not be used interchangeably because they define different iTreg subsets that overlap only in part. CD25high is the most relevant iTreg marker. These conclusions should be considered when studies and experiments involving iTreg phenotypes are compared.

Effects of Aflatoxin on the Proportions of Peripheral Blood Leukocytes and Alpha-Naphtyl Acetate Esterase (ANAE) Positive Lymphocytes in the Mouse

Summary In this study detrimental effects of aflatoxin (AF) on the peripheral blood formula and the alpha naphthyl acetate esterase (ANAE) - positivity profile of peripheral blood lymphocytes (PBL) on the mice were determined. A total of 40 white mice were randomly divided in to 5 groups each having 8 animals. The first group served as a control and received standard diet. The remaining 4 groups were fed diets containing 200, 400, 800 and 1600 ppb AF, respectively. The results of this study have revealed that AF given by the food caused significant declines both in the proportion of PBL and in the percentages of ANAEpositive peripheral blood lymphocytes (T-lymphocytes) in a dose dependent manner. These results may be concerned as a haematological evidence for immuno-suppressive effect of AF on cell-mediated immunity.

Changes in the proportions of peripheral blood lymphocytes in patients with worn implants.

We compared the peripheral blood and periprosthetic tissues of 53 patients at revision arthroplasty with those of 30 patients at primary arthroplasty to determine whether there is a systemic difference in lymphocytes in patients with worn hip implants. The absolute number and relative proportion of lymphocytes bearing CD2, CD3, CD4, CD8, CD16, CD19, HLA-DR, kappa and lambda antigens were compared with the levels of IL-1beta, IL-6 and PGE2 in the pseudosynovial membrane as well as with a semiquantitative estimate of metal and polyethylene particles, necrosis and chronic inflammation and the total concentration of metals within the periprosthetic tissues. There was a significant increase in the relative proportion of CD2-positive T-cells and CD16-positive natural killer cells in the peripheral blood at revision arthroplasty compared with primary arthroplasty and an increased proportion of CD8-positive T-cells and a decreased ratio of CD4 to CD8 (helper inducer/suppressor cytotoxic cells). Three control patients, who went on to have revision surgery, had values at primary arthroplasty which were similar to those of patients at the time of revision surgery. These differences did not correlate with the local concentration of metal, plastic or cement or inflammatory response or the type of prosthesis. An inverse correlation was noted between the necrosis in the periprosthetic tissue and both the local production of IL-6 and the absolute numbers of T-cells in peripheral blood. We conclude that there may be several cell-mediated systemic immune responses to aseptic loosening, at least one of which may be directly related to events in the periprosthetic tissues. We cannot exclude the possibility that the changes in the proportion of CD8-positive cells reflected a predisposition, rather than a reaction, to loosening of the implant.

Changes in the proportions of peripheral blood lymphocytes in patients with worn implants

We compared the peripheral blood and periprosthetic tissues of 53 patients at revision arthroplasty with those of 30 patients at primary arthroplasty to determine whether there is a systemic difference in lymphocytes in patients with worn hip implants. The absolute number and relative proportion of lymphocytes bearing CD2, CD3, CD4, CD8, CD16, CD19, HLA-DR, kappa and lambda antigens were compared with the levels of IL-1β, IL-6 and PGE2 in the pseudosynovial membrane as well as with a semiquantitative estimate of metal and polyethylene particles, necrosis and chronic inflammation and the total concentration of metals within the periprosthetic tissues. There was a significant increase in the relative proportion of CD2-positive T-cells and CD16-positive natural killer cells in the peripheral blood at revision arthroplasty compared with primary arthroplasty and an increased proportion of CD8-positive T-cells and a decreased ratio of CD4 to CD8 (helper inducer/suppressor cytotoxic cells). Three control patients, who went on to have revision surgery, had values at primary arthroplasty which were similar to those of patients at the time of revision surgery. These differences did not correlate with the local concentration of metal, plastic or cement or inflammatory response or the type of prosthesis. An inverse correlation was noted between the necrosis in the periprosthetic tissue and both the local production of IL-6 and the absolute numbers of T-cells in peripheral blood. We conclude that there may be several cell-mediated systemic immune responses to aseptic loosening, at least one of which may be directly related to events in the periprosthetic tissues. We cannot exclude the possibility that the changes in the proportion of CD8-positive cells reflected a predisposition, rather than a reaction, to loosening of the implant.

Effect of hormone replacement therapy on post-menopausal changes of lymphocytes and T cell subsets

Immunosenescence is associated with the occurrence of lethal diseases, such as infection and malignancy. Since endocrinosenescence occurs simultaneously with immunosenescence, we determined whether or not lymphocytes and T cell subsets were altered in post-menopausal women. The ability of hormone replacement therapy (HRT) to reverse or modify the aberrations of the cell populations observed in elderly women was also examined. Thirty-nine untreated post-menopausal women and 39 women on HRT were studied. The proportions of lymphocytes and T cell subsets (helper, cytotoxic and immature T cells, and naive and memory/activated T cells) were determined by two color flow cytometry. Thirteen women were examined before and during HRT. At late post-menopause (> or = 30 years post-menopausal period), the proportion of peripheral blood lymphocytes showed a tendency to decline (p=0.06) compared with that at early (< or = 10 years) post-menopause. Significant (p<0.05) decrease in naive T cells and an increase in memory/activated T cells occurred at late post-menopause compared to those at early post-menopause. The percentage of lymphocytes in women on HRT was significantly (p<0.05) higher than that in untreated women at late post-menopausal stage. Furthermore, in a prospective study, HRT induced a significant (p<0.02) increase in the percentage of lymphocytes but showed no effect on the aberrations of naive and memory/activated T cells. HRT prevents the decline in the lymphocytes observed in post-menopausal women. However, HRT appears not to influence the observed alteration in T cell subsets.

Effects of SIVmac infection on peripheral blood CD4+CD8+ T lymphocytes in cynomolgus macaques.

We have previously reported that CD4+CD8+ double-positive (DP) T cells with a resting memory phenotype exist in a substantial proportion of peripheral blood lymphocytes of adult cynomolgus macaques. In this study, we examined the effects of simian immunodeficiency virus of macaque (SIVmac) infection on DP T cells. In vitro, SIVmac239 nef-open (239) and its nef-deletion mutant replicated well in both CD4+CD8- and DP T cells. However, when the macaques were infected with 239, DP, but not CD4+CD8-, T cells were transiently increased in parallel with cell activation and viral replication, followed by depletion within 1 month postinfection. Interestingly, the nef gene was required for depletion but not for the increase and activation of DP T cells. These data suggest that the pathogenic SIV infection may downmodulate production and/or blood circulation of DP T cells by a Nef function-related mechanism(s) different from that for the depletion of CD4+CD8- T cells.

Predominant Expression of CD44 Splice Variant v10 in Malignant and Reactive Human Skin Lymphocytes

The remarkable functional diversity of the cell surface receptor CD44 may be due to expression of multiple variant isoforms generated by alternative splicing of variant exons. Functional and correlative data implicate a role of CD44 variant isoforms in adhesion dependent processes such as lymphocyte recirculation and tumor progression and metastasis. We have analyzed 25 primary cutaneous lymphomas and 35 reactive lymphoid cell skin infiltrates or T cell-mediated skin diseases for the expression of CD44 variant isoforms. Irrespective of histologic typing, staging, and grading, cutaneous lymphomas as well as nonmalignant skin-infiltrating CD3+ CD4+ and CD8+ T and CD19+ B lymphocytes exhibited a strong expression of CD44v10 and a moderate expression of CD44v3 as determined by immunohistochemistry, immunofluorescence microscopy, and mRNA analysis. Expression of v5, v6, v7, and v9-containing CD44 variant isoforms was not detected. Furthermore, flow cytometry revealed expression of CD44v10 on a significant proportion of peripheral blood lymphocytes from Sézary's syndrome patients and a remarkable co-expression with cutaneous lymphocyte antigen. These results indicate a distinct CD44 variant isoform expression pattern associated with skin-homing lymphocytes different to lymphatic cells at noncutaneous sites. This differential expression pattern of CD44 variant isoforms may contribute to the development of lymphocyte skin infiltrates and/or the unique biologic behavior of cutaneous lymphomas.

Expression of membrane receptor for tumour necrosis factor on human blood lymphocytes

Using a monoclonal antibody against the human p75 tumour necrosis factor receptor (TNFR-I) combined with a high-sensitivity immunofluorescence flow cytometric procedure, a proportion of peripheral blood lymphocytes can be shown to express TNFR-I constitutively. Approximately 50% of peripheral blood lymphocytes consisting mostly of CD4 cells and including most CD45R0-positive cells, express TNFR-I. Receptor expression is increased by a variety of activation signals. Only a minority (up to 30%) of tonsil B cells express measurable levels of TNFR-I. The tonsil B cells which express TNFR-I include both cells with a germinal centre cell phenotype and cells with the phenotype of the follicular mantle zone. Activation of B cells with anti-immunoglobulin, alone or in combination with interleukin-4 or interleukin-2, increases receptor expression, particularly in cells with the phenotype of mantle zone cells. The functional significance of constitutive expression of TNFR by blood and tissue lymphocytes is discussed.

Peripheral Blood Lymphocyte Subsets in Infants with Diarrhea with and without Giardia Lamblia Infection

The aim of the present study was to define the cellular immune response during gastrointestinal Giardia lamblia infection in young children. The level of lymphocyte subsets was determined in the peripheral blood of infants with G. lamblia-associated diarrhea or acute gastroenteritis and from control infants without diarrhea. The proportion of peripheral blood lymphocytes (PBL) expressing the CD8 marker (suppressor cytotoxic T cells) and the CD57 marker (natural killer cells and subset of CD8+ T cells) was highest in infants with acute gastroenteritis, lower in infants without diarrhea, and lowest among those with G. lamblia-associated diarrhea. The level of CD4+ PBL (helper T cells) did not differ significantly among the three groups of children tested. The level of memory, or helper-inducer, CD4+CD29+ PBL was increased markedly in acute gastroenteritis as compared with their level among the other two groups, whereas naive or virgin CD4+CD45RA+ PBL had the reciprocal distribution among the three groups of infants. In contrast to acute gastroenteritis from other causes, G. lamblia-associated diarrhea did not elicit changes in lymphocyte subsets.

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

Using a high-sensitivity immunofluorescence procedure, a proportion of blood lymphocytes can be shown to express the p55 chain of the IL-2 receptor (CD25, TAC) without in vitro stimulation (1, 2). In this study, we measured the proportion of peripheral blood lymphocytes expressing CD25 in patients with a diagnosis of HIV infection and compared the results with cells from controls. The mean value for HIV-positive samples was 15%, while controls gave a mean value of 31%. The difference between the groups was highly significant ( P < 0.001, Mann-Whitney U test). When expression of CD25 was examined separately in CD4-positive and CD8-positive T cells and in B cells, there was a wider spread of values in the HIV group compared with controls, but no systematic difference. In the patient group studied (110 samples from 53 patients) there was a weak correlation between CD25 and CD4 expression (correlation coefficient r = 0.21, P < 0.02), but there were patients with low CD25 and high CD4 as well as patients with high CD25 and low CD4, suggesting that CD25 can vary independently of changes in CD4 lymphocytes. Although the majority of very low values of CD25 (<10%) were found in patients with stage IV disease, such low values were also common in Stage II disease.

Serum immunoglobulins and lymphocyte subsets in chronic lymphocytic leukemia.

The concentrations of serum immunoglobulins were correlated to the stage of disease and the proportions of peripheral blood lymphocyte subsets in 25 untreated patients with B-cell chronic lymphocytic leukemia (CLL). Diminished levels of at least one serum immunoglobulin were present in 77% of all patients with CLL and 73% of patients with Stage 0 disease. The mean concentration of IgG, IgM, and IgA decreased with advancing stage of CLL. The percentages of total T, T-helper (TH), and T-suppressor (TS) cells in the peripheral blood were less in patients with CLL than in healthy persons, but the absolute concentrations of total T, TH, and TS cells were greater in patients with CLL than controls (P less than 0.02). The absolute number of B-cells (P less than 0.01) and null cells (P less than 0.001) was also increased in patients with CLL, particularly those patients in advanced stages of CLL. These findings suggest that the hypogammaglobulinemia associated with CLL first occurs during the earliest stage of disease and may be related to the alterations in the proportion of peripheral blood lymphocytes.

Transient immune deficiency in patients with acute Epstein-Barr virus infection

To study the effect of primary Epstein-Barr virus (EBV) infection on antigen-specific antibody production, we immunized 17 college students who had developed acute infectious mononucleosis with the T-cell dependent neoantigen bacteriophage φX174. During the early phase of infectious mononucleosis, the proportion of peripheral blood lymphocytes displaying la and T8 (CD8) phenotypes was increased and the T helper/suppressor ( T4 T8 ) ratio was decreased (<1). These abnormalities disappeared during the convalescent phase. Correlating with EBV-induced changes in T lymphocytes, we demonstrated depressed humoral immune responses to bacteriophage φX174 both in vivo and in vitro, In vitro coculture experiments indicated that the la + suppressor T cells could inhibit antibody production and isotype switch. Removal of T8 + lymphocytes from patient T cells normalized in vitro antibody synthesis. In addition, impaired B-cell function was shown to be in part responsible for deficient antibody production. These studies demonstrate that infection with EBV affects both B and T lymphocytes and causes a broad-based transient immune deficiency in patients with uncomplicated infections mononucleosis.

Lymphocyte receptors for human erythrocytes in newborn infants and adults. Expression on fresh and lectin-stimulated cells.

Lymphocyte receptors for human erythrocytes (HRBC) have been demonstrated by an optimized technique using neuraminidase-treated HRBC and high-protein diluent. Mean values of 55 and 50% reactive lymphocytes were found in the peripheral blood of newborn infants and adult donors, respectively. The HRBC receptor was labile under tissue culture conditions in vitro, in contrast to the receptors for sheep erythrocytes, Fc of IgG, and complement. Short-term culturing of lymphocytes with T cell mitogens (phytohemagglutinin, concanavalin A) increased the proportion of HRBC-receptor-bearing lymphocytes. Pokeweed mitogen, being mainly a B cell stimulator, was less effective in activating lymphocytes to resynthesize the receptor. It is concluded that the HRBC receptor is probably not a stable marker for a single subpopulation of human T lymphocytes. During the first week of life, the HRBC receptor is expressed on at least the same proportion of peripheral blood lymphocytes as in adults.