Relative Proportions Of CD4 Research Articles

Abstract P2-05-03: Integrated analysis of mismatch repair, PD-L1, and immune microenvironment status in pregnancy-associated breast cancers

Abstract Introduction: Breast cancer (BC) occurring during gestation or lactation is rare, yet highly challenging under both biological and clinical standpoints. This condition, referred to as pregnancy-associated (PA) BC (PABC), shows enrichment in mismatch repair (MMR) deficiency mutational signature, higher expression of immune-checkpoint genes, and less tumor-infiltrating lymphocytes (TILs) compared to non-PA BCs. Despite these insights, no comprehensive data on MMR protein status, immune checkpoints, and immune microenvironment are currently available for these tumors. The aim of this study was to characterize the MMR status and immunologic milieu of PABC. Methods: Among a multi-Institutional database comprising 142 PABCs, we conducted a comparative analysis of a cohort of PABC (n=29) and a control group of age-matched non-PA BCs (n=74). Distinct areas of each tumor and the corresponding normal breast tissue were incorporated into a tissue microarray (4-6 cores per case, mean 4.5). For all cases, both stromal and intratumoral TILs were quantified according to the International TILs Working Group recommendations. Representative slides were subjected to immunohistochemical (IHC) analysis of the MMR proteins (i.e. MLH1, MSH2, MSH6, and PMS2), programmed death-ligand 1 (PD-L1), CD4, and CD8. Cases were classified as MMR-proficient (pMMR), MMR-deficient (dMMR), and, when the protein was expressed only in a part of the tumor, MMR-heterogeneous (hMMR). PD-L1 expression was evaluated separately in the tumor cells, stromal TILs, and intratumoral TILs. Finally, the relative proportion of CD4+ and CD8+ cells was assessed in both stromal and intratumoral TILs. Results: The study group included 4 (14%) Luminal A, 10 (35%) Luminal B, 4 (14%) non-luminal HER2+, and 11 (37%) triple-negative (TN) PABCs. Taken together, both the dMMR and hMMR status were more common in PABCs than in non-PA BC (n=3/29, 19% vs. n=6/74, 8% and n=7/29, 24% vs. 14/74, 19%, respectively). Specifically, dMMR was seen in Luminal A (n=2, 50%) and in TN (n=1, 9%) PABCs. Conversely, in non-PA BCs, all Luminal A (n=15, 100%) were pMMR, while 5/45(11%) Luminal B and 1/13 (7%) TNBC were dMMR. Despite no differences were observed in intratumoral TILs, PABCs showed significantly higher levels of stromal TILs (p=0.01). Compared to the control group, PD-L1 expression in PABCs was significantly higher in the tumor cells and in stromal TILs (p<0.01) but not in intratumoral TILs. Hence, 9 (31%) PABCs were PD-L1+, with tumor proportion scores (TPS) ranging from 2 to 10 (mean 5), while only 4 (5%) non-PA BCs were PD-L1+ (TPS 2-20, mean 8)(p=0.01). The expression of PD-L1 in stromal TILs was higher in PABCs (n=9, 31%) than in the controls (n=19, 26%)(p=0.005). In Luminal tumors, both the CD4+ and CD8+ populations were more represented than in non-PA BCs (p=0.01), while in TNBC only the relative proportion of CD4+ cells was significantly higher (p=0.02). Discussion: This study is the first to investigate the immune response alongside the MMR status by IHC in PABCs. Our findings broaden the understanding of the immunobiology underpinning PABC, suggesting that in these tumors i) MMR protein alterations occur at higher frequency than in non-PA BCs; ii) the tumor cells and tumor microenvironment may be capable to suppress the adaptive arm of immune system through the expression of PD-L1; and iii) lymphocytes located at the periphery rather than those inside of the tumor are likely to be implicated in the immune modulation. Conclusion: The MMR system and immune microenvironment may play a consistent role in the natural history of PABCs. An intimate knowledge of the multifaceted interplay between tumor and tumor immune microenvironment is likely to unveil clinically relevant mechanisms that may have a positive net health impact for women with BC during gestation or lactation. Citation Format: Nicola Fusco, Elena Guerini-Rocco, Barbara Buonomo, Roberto Croci, Caterina Fumagalli, Gianluca Lopez, Giorgio A Croci, Letterio Runza, Elham Sajjadi, Concetta Blundo, Luca Despini, Massimo Giroda, Viviana E Galimberti, Paolo Veronesi, Massimo Barberis, Stefano Ferrero, Giovanna Scarfone, Silvano Bosari, Giuseppe Viale, Fedro Peccatori. Integrated analysis of mismatch repair, PD-L1, and immune microenvironment status in pregnancy-associated breast cancers [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-05-03.

Immune signatures for HIV-1 and HIV-2 induced CD4+T cell dysregulation in an Indian cohort

BackgroundHIV-2 infection is characterised by a longer asymptomatic phase and slower AIDS progression than HIV-1 infection. Identifying unique immune signatures associated with HIV-2 pathogenesis may thus provide therapeutically useful insight into the management of HIV infection. This study examined the dynamics of the CD4+T cell compartment, critical in disease progression, focussing on chronic HIV-2 and HIV-1 infected individuals at various stages of disease progression.MethodsA total of 111 participants including untreated and treated HIV infected individuals and seronegative individuals were enrolled in this study. The relative proportion of CD4+T cell subsets, expressing CD25 (IL-2Rα) and CD127 (IL-7R), in HIV infected individuals and seronegative controls were assessed by multiparametric flow cytometry. Additionally, levels of immune activation and cytotoxic T lymphocytes in both the CD4+T and CD8+T cell compartments was evaluated.ResultsBoth treated and untreated, HIV-1 and HIV-2 infected individuals showed apparent dysregulation in CD4+ T cell subset frequency that was associated with disease progression. Furthermore, longitudinal sampling from a group of HIV-1 infected individuals on virologically effective ART showed no significant change in dysregulated CD4+T cell subset frequency. For both ART naïve and receiving groups associations with disease progression were strongest and significant with CD4+ T cell subset frequency compared to per cell expression of IL-2Rα and IL-7Rα. In untreated HIV-2 infected individuals, T cell activation was lower compared to ART naïve HIV-1 infected individuals and higher than seronegative individuals. Also, the level of Granzyme-B expressing circulating T cells was higher in both ART-naïve HIV-1 and HIV-2 infected individuals compared to seronegative controls.ConclusionDysregulation of IL-2 and IL-7 homeostasis persists in CD4+T cell subsets irrespective of presence or absence of viremia or antiretroviral therapy in HIV infection. Furthermore, we report for the first time on levels of circulating Granzyme-B expressing CD4+T and CD8+T cells in chronic HIV-2 infection. Lower immune activation in these individuals indicates that persistent immune activation driven CD4+T cell depletion, as observed in untreated HIV-1 infected individuals, may not be as severe and provides evidence for a disparate pathogenesis mechanism. Our work also supports novel immunomodulatory therapeutic strategies for both HIV-1 and HIV-2 infection.

Abstract 560: A pan-inflammatory and precancerous disease analysis reveals key biological characteristics in chronic inflammatory diseases with high oncogenic risk

Abstract It has long been observed that cancer development tends to be associated with chronic inflammation. Recent epidemiology studies have suggested chronic inflammation may be causally linked to a larger number of sporadic cancers. In this work, we have conducted a Pan-inflammatory and precancerous diseases analysis by comparing the 173 transcriptomics data sets consisting 4073 disease and 2669 normal human tissue samples of 10 cancer prone and 8 cancer independent inflammatory diseases, 11 precancerous diseases or benign tumors and 20 cancer types, aiming to identify fundamental differences between cancer-prone chronic inflammations and cancer-independent chronic inflammations and what biological characteristics cause cancer initiation or increased oncogenic risk. By applying differential gene expression, co-expression network, our in-house immune cell deconvolution and machine learning based hypoxia/oxidative stress prediction methods on the collected data, we have discovered the cancer prone chronic inflammatory diseases consistently have: (1) elevated relative proportion of CD4+ T, Macrophage, and Neutrophil cells, (2) decreased CD8 + T, adipocyte, monocyte and B cells, (3) highly disorder tissue repair phase I - IV related pathways, (4) increased oxidative stress level associated with Macrophage and Neutrophil proportions, (5) elevated iron ion metabolism, (6) over expressed extracellular glycosaminoglycan metabolism and (6) suppressed mitochondrial activity. These analyses results strongly suggest that there is a necessary pathway for the majority or all chronic inflammatory diseases to become cancerous, namely consecutively dysregulated tissue repair process, increased reactive oxygen species producing immune cells, damage of extracellular matrix, Fenton reaction and production of hydroxyl radical and dysregulated mitochondrial activity. We believe these new insights could provide highly useful information in guiding future studies of inflammation associated cancers. Citation Format: Chi Zhang, Fang Yao, Sha Cao, Tao Sheng, Sen Liang, Wei Du, Ying Xu. A pan-inflammatory and precancerous disease analysis reveals key biological characteristics in chronic inflammatory diseases with high oncogenic risk [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 560. doi:10.1158/1538-7445.AM2017-560

Abstract S1-02: Lymphocytic infiltration in invasive lobular breast cancer

Abstract Background: The presence and prognostic value of tumor infiltrating lymphocytes (TILs) in invasive breast carcinoma has been demonstrated in several studies, especially in the triple-negative and HER2-positive subtypes. So far, TILs have not been investigated with sufficient detail in invasive lobular breast cancer (ILBC). Here we therefore aimed at: first, assessing the distribution of stromal TILs in ILBC; second, correlating the presence of TILs with standard clinical and pathological markers; third, exploring associations of TILs with recurrent genomic alterations; and, fourth, comparing the lymphocytic composition of ER-positive/HER2-negative lobular to ER-positive/HER2-negative ductal tumors. Material and methods: The percentage of stromal TILs was independently assessed according to Salgado et al. (Ann Oncol 2015) by three pathologists on full-face hematoxylin and eosin slides in a well-annotated retrospective series of 614 primary ILBCs previously characterized at the genomic level. The median value of TILs was used for the analyses. For the association analyses, we focused on the more homogeneous group of ER-positive/HER2-negative ILBC (555/614). Breast cancer-free interval was used as survival endpoint and the analyses were censored at 12 years of follow-up. The comparison of the lymphocytic composition (relative percentage of CD45+ TILs which are CD4+, CD8+ or CD19+) was assessed by FACS in a separate prospective cohort of 51 ER-positive/HER2-negative lobular and 112 ER-positive/HER2-negative ductal tumors. Results: The intraclass correlation coefficient between the three pathologists was 0.71 (95%CI:0.65-0.76). The median percentage of stromal TILs was 5% and the interquartile range 5-10%, with only 9% of the samples having ≥ 20%. Greater numbers of TILs were significantly associated with younger age at diagnosis, axillary lymph node involvement, high proliferative tumors as assessed by Ki67, and with the mixed non-classic ILBC subtypes. Greater numbers of TILs were associated with worse prognosis (HR=1.22; 95%CI:1.07-1.38, p=0.003) only in the unadjusted analysis, as it lost significance after adjustment for standard clinical and pathological variables. Greater numbers of TILs were observed in tumors harboring ARID1A, BRCA2, KMT2C and TP53 mutations, as well as chr3p21.31 and chr8q24.23 (PTK2) loss; whereas lower numbers were observed in tumors with ERBB3 mutations as well as chr7p and chr11q14.1 (PAK1) gains. There were no significant differences in the relative proportion of CD4+, CD8+ or CD19+ lymphocytes between ER-positive/HER2-negative lobular and ductal tumors. Conclusion: In this work, which reports to our knowledge on the largest series of ILBC ever assessed for TILs, we showed that most ILBCs were characterized by low lymphocytic infiltration. Besides the association of TILs with clinical and pathological features of ILBC patients, we found that higher TIL levels were observed in the presence of specific mutations and copy number alterations. Higher numbers of TILs were associated with worse prognosis at the univariate analysis. Finally, based on the assessed markers, we have no evidence of differential lymphocytic composition between ER-positive/HER2-negative lobular and ductal tumors. Citation Format: Desmedt C, Salgado R, Buisseret L, Zoppoli G, Fornili M, Van den Eynden G, Garaud S, Gundem G, Rothé F, Brown D, Kheddoumi N, Rouas G, Galant C, Bertucci F, Piccart M, Campbell P, Viale G, Larsimont D, Willard-Gallo K, Biganzoli E, Pruneri G, Sotiriou C. Lymphocytic infiltration in invasive lobular breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr S1-02.

Analysis Of Immune Cell Populations Before and After Autologous Hematopoietic Stem Cell Transplant For Multiple Myeloma: Association With Early Recovery Of Absolute Lymphocyte Count and Progression-Free Survival

The treatment of transplant-eligible, multiple myeloma (MM) patients usually consists of induction therapy followed by autologous hematopoietic stem cell transplant (ASCT). In addition to typical cytogenetic and biochemical prognostic factors, there are other risk factors that predict for relapse and progression after ASCT. This includes absolute lymphocyte count (ALC) recovery (>0.5 cells/μL) by day +15 post ASCT, which has previously been shown to correlate with prolonged progression-free (PFS) and overall survival (OS). In a cohort of 70 MM patients who received high dose melphalan with ASCT between 8/2007 and 9/2012, we performed a comprehensive immunophenotyping panel including 35 T-, B-, NK- and Dendritic Cell (DC)-cell subsets a median of 25 days before ASCT (N=70), at day +30 post-ASCT (N=40) and at day +100 (N=51) post-ASCT. Specifically, the immunophenotyping panel included total numbers of T cells (CD3+, CD4+, CD8+), B cells (CD19+, CD20+), NK cells (CD56+CD16+) and myeloid (CD11c+) and plasmacytoid (CD123+) dendritic cells. T cell subsets included the relative proportions of double positive (CD3+CD4+CD8+), double negative (CD3+CD4-CD8-), CD4+ and CD8+ Naïve (CD3+ CD45RA+ CD45RO- CD27+), CD4+ and CD8+ central memory (CD3+ CD45RA- CD45RO+ CD27+), CD4+ and CD8+ effector memory (CD3+ CD45RA- CD45RO+ CD27-), recent thymic emigrants (CD3+ CD4+ CD45RA+ CD31+), and T-regulatory cells (CD3+ CD4+ CD25(br), CD3+CD4+CD25+CD127(d), CD3+CD4+CD25+CD127-HLADr+). B cell subsets included proportions of naïve (CD19+ CD27-), and memory (CD19+ CD27+, pre-switch CD19+ IgD+ CD27+, post-switch CD19+ IgD- CD27) cells. All patients survived to day +100. We examined MM response to ASCT, recovery of ALC by day +15 post-ASCT, clinically significant infections, PFS and OS. Characteristics in 70 patients pre-ASCT were: median (range) age 60 (28-75) yrs; 54% females; 26% KPS ≥90; response to most recent therapy was 13% in CR/sCR, 40% in VGPR, 41% in PR, 6% stable disease. MM responses at day + 100 included: 51% achieved or maintained CR/sCR, 17% VGPR, 10% PR, 24% SD and 6% progressed. The frequency of different immune cell subsets at either pre-ASCT or day +100 post-ASCT were not associated with CR/sCR status at day 100 post-AHSCT. ALC recovery by day +15 post-ASCT was associated with significantly longer median PFS (651 vs 288 days, P=0.001) and OS (804 vs 391 days, P=0.02) than those who did not recover ALC by day 15. For patients showing early recovery of ALC, the absolute numbers of T-cells pre-ASCT (P=0.08), as well as the proportion of CD4+ naïve (P=0.07) and CD8+ NK (CD8+/CD16+/CD56+, P=0.06) populations tended to be higher, whereas the absolute counts of gamma-delta T cells (P=0.02), CD4+ helper (P=0.03, See Figure), CD8+ effector (P=0.02) T-cells and total B-cell count (P=0.05) were significantly higher as compared to patients who did not achieve ALC recovery by day +15. Of note, within the T-cell compartment, CD4+ central memory (P=0.02, see Figure), CD8+ central memory (P=0.05), T-regulatory (T reg) (P=0.02, CD4+25+) populations were significantly lower. The distribution of different immune cell subsets pre-ASCT was not associated with development of clinically significant infections before day +100 post-AHCT; however, the proportion of memory B cells measured at day+100 was significantly higher (p=0.02) in patients who had experienced an infection before day +100. In the present study we show that the distribution of different immune cell populations correlates with ALC recovery in MM. Moreover, we also confirmed the association of ALC recovery with prolonged PFS and OS. The increase in the relative proportions of CD4+ and CD8+ effector cell subpopulations and the decrease in CD4+ and CD8+ central memory and T-reg populations demonstrate that the pre-ASCT effector cell phenotype contributes to faster ALC recovery, and improved PFS/OS. Therapeutic strategies to alter the pre-ASCT and/or day + 100 immune phenotype may improve outcomes after ASCT. [Display omitted] [Display omitted] Disclosures:McCarthy:Janssen: Honoraria; Celgene: Consultancy.

Treatment of autoimmune diabetes in NOD mice by Toll-like receptor 2 tolerance in conjunction with dipeptidyl peptidase 4 inhibition

We have shown that chronic administration of the Toll-like receptor 2 (TLR2) agonist Pam3CSK(4) prevents diabetes in NOD mice by inducing TLR2 tolerance of dendritic cells (DCs). We have also reported that a novel dipeptidyl peptidase 4 (DPP4) inhibitor, DA-1229, could increase beta cell mass. Here we investigated whether a combination of DPP4 inhibition, with beneficial effects on beta cell mass, and TLR2 tolerisation, protecting beta cells from autoimmune destruction, could treat a model of established type 1 diabetes. Diabetic NOD mice were treated with 100μg Pam3CSK(4), administered three times a week for 3weeks, in combination with feeding with chow containing 0.3% DA-1229. Beta cell mass and proliferation were studied by immunohistochemistry. DC tolerance was assessed by studying diabetogenic CD4(+) T cell priming after adoptive transfer and expression of costimulatory molecules on DCs by flow cytometry. We observed reversal of diabetes in NOD mice by Pam3CSK(4)+DA-1229 but not by either Pam3CSK(4) or DA-1229 alone. Beta cell mass and the number of proliferating beta cells were significantly enhanced by Pam3CSK(4)+DA-1229, but not by either Pam3CSK(4) or DA-1229 alone. Diabetogenic T cell priming by DCs and upregulation of costimulatory molecules after ex vivo stimulation were attenuated in mice treated with Pam3CSK(4)+DA-1229, indicating DC tolerance. The relative proportions of CD4(+) T cells, CD8(+) T cells, B cells, DCs, macrophages and regulatory T cells, and T-helper polarisation were unchanged by treatment with Pam3CSK(4)+DA-1229. These data demonstrate that a combination of TLR2 tolerisation and DPP4 inhibition can reverse early-onset diabetes in NOD mice.

Probing the Impact of AMD3100/GCSF Mobilization on the Peripheral Blood T Cell Content Using a Rhesus Macaque Model: Increased Proportions of FoxP3+/CD4+ T Cells Occur After Mobilization and Leukapheresis

AbstractAbstract 350 Introduction:Leukapheresis is a widely utilized modality for collecting hematopoietic stem cells (HSCs). While collection of CD34+ cells with stem-cell activity is the primary goal of most mobilization and leukapheresis procedures, these cells only represent ∼1% of most leukapheresis products. The profile of the non-CD34+ cells is likely influenced by the choice of mobilization strategy, and has the potential to profoundly impact the post-transplant immune milieu of the transplant recipient. Two of the most critical of the CD34-negative cell populations that are collected during leukapheresis include effector and regulatory T cells. Thus, in evaluating mobilization regimens, the impact on these regimens on the mobilization of each of these T cell populations into the peripheral blood should be rigorously evaluated. Methods:We used a rhesus macaque model to determine the impact that mobilization with AMD3100 (a.k.a., Plerixafor or Mozobil®)+ G-CSF (“A+G”) had on peripheral blood CD4+ and CD8+ effector T cell populations as well as on FoxP3+/CD4+ T cells. Three rhesus macaques were mobilized with 10ug/kg SQ of G-CSF for five consecutive days prior to leukapheresis. AMD3100 was administered at 1mg/kg SQ in combination with the last dose of G-CSF two hours prior to leukapheresis. Leukapheresis procedures were performed for two hours using a modified CS3000 Plus cell separator. A peripheral blood sample was taken before cytokine therapy, just prior to leukapheresis following mobilization, one hour during leukapheresis, and at the end of the procedure. These samples were analyzed by multicolor flow cytometry using a BD LSRII flow cytometer. Results:Bulk, effector, and regulatory T cell subpopulations were analyzed flow cytometrically. The proportion of total CD3+ T cells remained stable during mobilization and apheresis: Thus, CD3+ T cells represented 77% of peripheral blood lymphocytes prior to mobilization, and 69% post-apheresis). The balance of CD4+ to CD8+ T cells was also relatively stable. Thus, for one of the three animals tested, the CD4+ and CD8+ proportions remained unchanged after apheresis. For two animals, the average CD4+ % decreased from 67% prior to mobilization to 52% post-apheresis. In these two animals, there was a reciprocal increase in the % of CD3+ T cells that were CD8+ (28% pre-G+A to 40% post-apheresis). The CD28+/CD95- naïve (Tn), CD28+/CD95+ central memory (Tcm) and CD28-/CD95+ effector memory (Tem) subpopulation balance of CD4+ and CD8+ T cells was also determined, by comparing the relative percentages of each subpopulation post-apheresis with their relative percentages prior to mobilization. Compared to their pre-G+A percentages, the post-apheresis CD4+ percentages of Tn, Tcm and Tem were 92%, 93% and 160%, respectively. Thus, the relative proportions of Tn and Tcm CD4+ cells decreased post-apheresis, while the relative proportion of CD4+ Tem increased compared to cytokine administration. For CD8+ T cell subpopulations, the post-apheresis proportions of Tn, Tcm, and Tem compared to their pre-G-CSF proportions were 99%, 70% and 130%, respectively–thus demonstrating the same direction of change as observed for CD4+ T cells. The most striking change in T cell subpopulations occurred in the CD4+/FoxP3+ compartment. The proportion of CD4+ T cells expressing FoxP3 increased by an average of 600% when post-apheresis samples were compared to pre-mobilization samples (FoxP3+ cells were 9.6% of CD4+ T cells post-apheresis versus 1.5% pre-GCSF). An average of 32% of these FoxP3+ CD4+ T cells expressed high levels of CXCR4. CXCR4 expression has been previously documented on human FoxP3+ T cells (Zou et al., Cancer Res, 2004), but this is the first observation of high level expression of CXCR4 on macaque FoxP3+ CD4 T cells, or of their ability to be efficiently mobilized with AMD3100. Discussion:These results suggest that treatment with AMD3100 and G-CSF may mobilize T cell subsets into the peripheral blood that could have beneficial effects during allo-transplantation. The combination of an increase in Tem cells, which have been observed to have decreased ability to cause GvHD (Zheng et al., Blood 2008), along with FoxP3+/CD4+ T cells, which may have regulatory functions, suggests that A+G mobilization could produce an apheresis product with a beneficial CD34-negative cell profile for allogeneic transplantation. Disclosures:No relevant conflicts of interest to declare.

Somatostatin-14 induces different changes in the thymus of peripubertal and young adult rats

Bearing in mind the role of somatostatin in thymus functions, and changes of somatostatin level and expression of its receptors during postnatal life, the aim of this study was to investigate whether centrally applied SRIH-14 induces different changes in the thymic compartments and thymocyte profile in peripubertal and young adult rats. To this end, 4- and 10-week-old male AO rats were cannulated and treated intracerebroventriculary with three doses of SRIH-14, applied every other day. In peripubertal rats, SRIH-14 decreases thymic relative weight and volume, as well as the volume of thymic compartments, especially of deep cortex, as a result of thymocytes loss by apoptosis. Also, SRIH-14 increases the percentage of immature thymocytes preceding the DPTCRαβlow cells (DNTCRαβ-/low, DPTCRαβ-, SPCD8TCRαβ-/low and SPCD4TCRαβ-/low), decreases the percentages of DPTCRαβlow and DPTCRαβhi cells, while the relative proportion of CD4+/CD8+TCRαβhi cells remained unaltered. In young adult rats, SRIH-14 does not lead to changes in relative thymus weight, although decreases the thymic cortex cellularity and volume. In addition, decreases the percentage of DPTCRαβ-/hi cells and increases the percentages of cells within DNTCRαβhi and both SP subpopulations, but much more of the CD8+TCRαβhi subset. These results suggest that the effects of SRIH-14 on the thymus and thymocytes subpopulations are age-dependent.

Formula Feeding Skews Immune Cell Composition toward Adaptive Immunity Compared to Breastfeeding

The ontogeny of the immune system and the effect thereon by type of infant feeding is incompletely understood. We analyzed frequencies and composition of immune cells in blood of breastfed (BF) and formula-fed (FF) infants at 1.5, 4, and 6 mo of age. Three formulas with the same protein concentration but with varying levels of alpha-lactalbumin and caseinoglycomacropeptide were compared. Twenty-nine exclusively BF infants served as reference, and 17 infants in each formula group completed the study. Whole blood and PBMCs were analyzed by flow cytometry and immunoflow cytometry, respectively. Leukocyte count of BF infants increased with time due to increased frequency of neutrophils. Lymphocyte count was high at 1.5 mo and was unchanged over time, as were the relative proportions of CD4+ alphabetaT cells, CD8+ alphabetaT cells, B cells, NK cells, and gammadeltaT cells. Most CD45R0+CD3+ cells were HLA-DR- and hence memory cells. Compared with breastfeeding, formula feeding resulted in a significant decrease in proportion of NK cells, but a significant increase in naive CD4+ alphabetaT cells and an elevated CD4-to-CD8 ratio, that is, 3.3 in the combined FF groups compared with 2.6 in the BF group. No significant differences were found between the three groups of FF infants. In conclusion, blood cells of lymphoid lineage did not change significantly in frequencies or composition from 1.5 to 6 mo of age in BF infants. In contrast, FF infants displayed an ongoing maturation of adaptive immunity cells and a delayed recruitment of innate immunity cells as compared with BF infants.

The impact of graft composition on clinical outcomes in unmanipulated HLA-mismatched/haploidentical hematopoietic SCT

This study examines the absolute numbers and relative proportions of CD4+, CD8+, CD14+ and CD34+ cells contained in allografts and their impact on early engraftment and later clinical outcomes in 141 patients with hematological malignancies who underwent unmanipulated HLA-mismatched/haploidentical hematopoietic SCT without in vitro T-cell depletion. These patients received G-CSF-primed BM grafts (G-BM) and peripheral blood grafts (G-PB) following a modified regimen of BU/CY 2 plus antithymocyte globulin. Multivariate analysis showed that high CD34+ cell numbers were associated with accelerated plt engraftment (P=0.001). Meanwhile, patients with a higher CD4/CD8 ratio in G-BM (> or =1.16) had a survival disadvantage (P<0.01) and a trend towards relapse (P=0.086) after controlling for disease status. A higher CD4/CD8 was also associated with a significantly increased risk of acute GVHD grades II-IV (P=0.013), even after adjusting for an ABO major mismatch. No aspect of graft composition affected neutrophil engraftment or chronic GVHD. In conclusion, the differences in CD34+ cell dose and the CD4/CD8 ratio in grafts seem to affect engraftment and clinical outcomes; in particular, a lower CD4/CD8 ratio in primed BM graft is associated with a survival benefit.

Comparison of ventricular and lumbar cerebrospinal fluid T cells in non-inflammatory neurological disorder (NIND) patients

The aim of the present study was to define the cellular composition of ventricular, as compared with lumbar, cerebrospinal fluid (CSF) in patients with non-inflammatory neurological disorders (NIND). We addressed this issue by determining the cellular composition of lumbar CSF from patients with normal pressure hydrocephalus (NPH) who were undergoing lumbar CSF drainage during evaluation for shunting procedures, and evaluating ventricular CSF from a subset of these who underwent subsequent placement of ventriculoperitoneal shunts. We determined the cellular composition of lumbar CSF from 18 patients with NPH, and found that the leukocyte differentials, and relative proportions of CD4 + and CD8 + central memory (T CM), effector memory (T EM) and naïve cell (T Naive) populations, were equivalent to those found previously in studies of CSF from patients with NIND. We further evaluated cells in the ventricular CSF of five patients who had previously undergone lumbar drainage. Leukocyte differential counts, as well as CD4 + and CD8 + T CM, T EM, and T Naive proportions, were equivalent in matched ventricular and lumbar CSF samples. These observations support the hypothesis that leukocytes enter the CSF in a selective fashion, at its site of formation in the choroid plexus. The results implicate CSF T cells in the immune surveillance of the central nervous system.

Neonatal Androgenization Affects the Intrathymic T-Cell Maturation in Rats

The thymus structure, expression of CD4/CD8/TCRαβ on thymocytes and thymocyte proliferative and apoptotic indexes were analyzed in sexually immature 30-day-old and in sexually mature 60-day-old female rats neonatally androgenized (NA) by subcutaneous injection of 500 µg testosterone propionate/day on days 1–3 and in their vehicle-administered counterparts. The treatment affected normal thymus development. Thus, at 30 days of age, there was a reduction in the thymus weight, reflecting a decrease in the main thymic compartments. However, at 60 days of age, thymus weight did not significantly differ from that in age-matched controls, since the cortical volume enlargement was followed by a proportional decrease in the medullary volume. In rats of both ages, the changes in thymic compartments most likely reflected alterations in the size of both lymphoid and nonlymphoid components. Furthermore, in NA rats, substantial changes in thymocyte phenotypic characteristics were registered, in spite of their age. In both groups of NA rats, a decrease in the relative proportion of the least mature CD4–8–TCRαβ– cells and in that of CD4+8– TCRαβ–/TCRαβ^low cells followed by an increase in the percentage of their successor CD4+8+TCRαβ–/TCRαβ^low cells was detected. In addition, in 30-day-old NA rats, the relative proportions of CD4+8+TCRαβ^high cells (just positively selected) and that of mature single positive (CD4+8– and CD4–8+) and CD4–8– double negative TCRαβ^high cells, were reduced, while in 60-day-old NA rats only the percentage of CD4+8+TCRαβ^high thymocytes was decreased. Thus, the study showed that the changes in the development of the hypothalamo-pituitary-gonadal axis induced by neonatal androgenization may affect the thymus development and intrathymic T-cell maturation.

Changes in Thymopoiesis in Myasthenia Gravis

This study was undertaken to investigate T-cell maturation in hyperplastic thymi of patients suffering from myasthenia gravis (MG). For this purpose, the expression of the major differentiational molecules (CD4, CD8, and CD3/TCRαβ) and that of the regulatory and activation molecules on thymocytes from MG patients and control subjects were estimated by flow cytometric analysis. In the MG patients the increase in relative proportion of immature (CD4−8− TCRαβ−) and the most mature (CD4+8− TCRαβhigh and CD4−8− TCRhigh encompassing immunoregulatory NKT) thymocytes followed by a decrease in that of CD4+8+CD3−/TCRαβ− cells was found. Furthermore, in these patients the relative proportion of CD4+HLA-DR+ and CD4+71+ cells was increased, whereas that of CD4+25+ cells was slightly, but significantly, decreased (reflecting, most likely, decreased contribution of T reg cells bearing this phenotype). Moreover, in MG thymi the percentage of CD45RA+ cells was reduced indicating changes in the selection processes. In keeping with this finding the reduced thymocyte apoptotic index and percentage of cells bearing apoptosing (CD4−8− TCRαβlow) phenotype were detected. In conclusion, the study demonstrates substantial changes in intrathymic differentiation of T cells in hyperplastic MG thymi and suggests alterations in selection events providing an increased escape of potentially autoreactive T-cell clones, on one side, and an altered maturation and/or selection of immunoregulatory cells (NKT and CD4+8−25+ T reg cells) keeping these cell clones under control, on the other side.

Differential proliferative response of NKT cell subpopulations to in vitro stimulation in presence of different cytokines.

Human Valpha24(+)Vbeta11(+) NKT (NKT) cells have immune regulatory activities associated with rejection of tumors, infections and control of autoimmune diseases. They can be stimulated to proliferate using alpha-galactosylceramide (KRN7000) and have the potential for therapeutic manipulation. Subpopulations of NKT cells (CD4(+)CD8(-), CD4(-)CD8(+) and CD4(-)CD8(-)) have functionally distinctive Th1/Th2 cytokine profiles and their relative numbers following stimulation may influence the Th1/Th2 balance, which may result in or prevent disease. We aimed to determine the effect of different cytokines in culture during stimulation of NKT cells on the relative proportions of NKT cell subpopulations. Our results show that all NKT cell subpopulations expanded following stimulation with KRN7000 and IL-2, IL-7, IL-12 or IL-15. Expansion capacity differed between subpopulations, resulting in different relative proportions of CD4(+) and CD4(-) NKT cell subpopulations, and this was influenced by the cytokine used for stimulation. A Th1-biased environment was observed after stimulation of NKT cells. NKT cells expanded under all conditions evaluated demonstrated significant cytotoxicity against U937 tumor cells. In view of the potential for NKT cell subsets to alter the balance of Th1 and Th2 environment, these data provide insights into the effects of NKT cell manipulation for possible therapeutic applications in different disease settings.

Murine model of BCG lung infection: dynamics of lymphocyte subpopulations in lung interstitium and tracheal lymph nodes.

C57Bl/6 female mice were infected with an intrapulmonary dose of 2.5 x 10(4) BCG (Mycobacterium bovis Bacillus Calmette-Guerin). Lymphocyte populations in lung interstitium and lung-associated tracheal lymph nodes (LN) were examined at 1, 2, 4, 5, 6, 8 and 12 weeks after infection. BCG load in lungs peaked between 4-6 weeks post-infection and declined to very low levels by the 12th week of infection. Lung leukocytes were obtained over the course of infection by enzyme digestion of lung tissue followed by centrifugation over Percoll discontinuous density gradients. By 4 to 6 weeks after infection, numbers of lung leukocytes had more than doubled but the proportions of lymphocytes (about 70%), macrophages (about 18%) and granulocytes (about 12%) remained essentially unaltered. Flow cytometric studies indicated: (i) the total number of CD3+ T cells in lungs increased by 3-fold relative to uninfected controls at 5 to 6 weeks post-infection, but the relative proportions of CD4 and CD8 cells within the T cell compartment remained unaltered; (ii) relative proportion of NK cells in lungs declined by 30% but the total number of NK cells (NK1.1+) per lung increased by about 50%, 5-6 weeks post infection; (iii) tracheal LN underwent marked increase in size and cell recoveries (6-10-fold increase) beginning 4 weeks after infection. While both T and B cells contributed to the increase in cell recoveries from infected tracheal LNs, the T/B ratio declined significantly but CD4/CD8 ratio remained unaltered. In control mice, IFNgamma producing non-T cells outnumbered T cells producing IFNgamma. However, as the adaptive response to infection evolves, marked increase occur in the number of IFNgamma producing T cells, but not NK cells in the lungs. Thus, T cells are the primary cell type responsible for the adaptive IFNgamma response to pulmonary BCG infection. Few T cells in tracheal LN of BCG infected mice produce IFNgamma, suggesting that maturational changes associated with migration to the lungs or residence in the lungs enhance the capability of some T cells to produce this cytokine.

Mycobacterium bovis BCG-induced granuloma formation depends on gamma interferon and CD40 ligand but does not require CD28.

Progressive granuloma formation is a hallmark of chronic mycobacterial infection. Granulomas are localized, protective inflammatory reactions initiated by CD4+ T cells, which contribute to control of bacterial growth and blockade of bacterial dissemination. In order to understand the costimulatory requirements that allow CD4+ T cells to directly or indirectly induce granulomas, we studied granuloma formation after 6 weeks in Mycobacterium bovis BCG-infected CD28- and CD40 ligand (CD40L)-deficient mice and compared it to granuloma formation in infected wild-type inbred mice and infected cytokine-deficient mice. We characterized granulomas morphologically in liver sections, analyzed granuloma infiltrating cells by flow cytometry, and measured cytokine production by cultured granuloma cells. CD28-deficient mice have no defect at the local inflammatory site, inasmuch as they form protective granulomas and control bacterial growth. However, there are fewer activated T cells in the spleen compared to infected wild-type animals, and quantitative differences in the cellular composition of the granuloma are observed by flow cytometry. In CD40L-deficient mice, the granuloma phenotype is very similar to the phenotype in gamma interferon (IFN-gamma)-deficient mice. Both IFN-gamma-deficient and CD40L-deficient mice form granulomas which prevent bacterial dissemination, but control of bacterial growth is significantly impaired. The relative proportion of CD4+ T cells in granulomas from both CD28(-/-) and CD40L(-/-) mice is significantly decreased compared with wild-type animals. Both models demonstrate that the phenotype and activation stage of systemic T cells do not always correlate with the phenotype and activation stage of the localized granulomatous response.

Differential effects of chronic propranolol treatment on the phenotypic profile of thymocytes from immature and adult rats

To elucidate a putative role of β-adrenoceptors in the modulation of intrathymic T-cell maturation, the expression of major differentiational antigens (CD4/CD8 and TCRαβ) on the thymocytes from both immature (aged 21 day at the beginning of the treatment) and adult (aged 75 days at the beginning of treatment) male rats subjected to a 15-day-long propranolol treatment (0.40 mg/100 g/day, s.c.) was analyzed by two- and one-color flow cytometry, respectively. Rats of matched age injected with saline served as controls. The propranolol treatment in immature but not adult rats caused a significant reduction in both the relative thymus weight and total thymocyte yield. In addition, a significant increase in the percentage of CD4+8+ double-positive cells, with a proportional decrease in the relative proportion of CD4+8− single positive cells, was found in immature rats. In contrast, a slight but significant decrease in the percentage of CD4+8+ cells with a parallel increase in the relative proportion of CD4+8− cells was found in adult rats. In both groups of rats, the percentage of TCRαβtotal thymocytes was increased: in immature rats this was due to an increase in the percentage of TCRαβlow thymocytes, while in the adult rats it reflected a rise in the relative proportion of TCRαβhigh cells. In conclusion, the study revealed that propranolol treatment in both immature and adult rats alters the relative proportion of CD4+8+ and CD4+8− thymocytes, but in opposite fashion, and the data suggest that this treatment affects distinct fractions within the population of CD4+8+ thymocytes with respect to expression of TCRαβ. The results also indicate that, regardless of rat sexual maturity, the development of thymocytes towards CD4−8+ T-cells is relatively insensitive to long-lasting β-adrenoceptor blockade.

The effect of segmental bronchoprovocation with allergen on airway lymphocyte function.

We hypothesized that allergen-induced airway eosinophilia is linked to activation or recruitment of T cells in the airway and generation of interleukin-5 (IL-5). To evaluate this hypothesis, we performed bronchoscopy with segmental antigen bronchoprovocation in 12 atopic subjects. Bronchoalveolar lavage (BAL) was done 5 min and 48 h after challenge with saline or antigen. Airway cells were isolated and then stimulated ex vivo with a T-cell mitogen, phytohemagglutinin (PHA), and cytokine release was determined. Cells retrieved from the saline-challenged segment secreted principally interferon-gamma (IFN-gamma) and IL-2. In contrast, cells obtained 48 h after allergen challenge secreted high levels of IL-5 and small but increased amounts of IL-4, IL-10, and granulocyte-macrophage colony-stimulating factor (GM-CSF). Although CD4+ T cells were a major source of IL-5, there were no significant changes in the relative proportion of CD4+ cells in response to bronchoprovocation. Additionally, ex vivo secretion of IL-5 by airway cells correlated closely with amounts of IL-5 and eosinophils present in the bronchoalveolar lavage fluid (BALF). These observations suggest that following exposure to allergen, airway T cells are functionally but not phenotypically different from resident airway T cells, and that T cells within the airway contribute to eosinophilic airway inflammation through the secretion of IL-5.

Hemorrhagic enteritis virus induced changes in the lymphocyte subpopulations in turkeys and the effect of experimental immunodeficiency on viral pathogenesis

We examined the changes in the lymphocyte subpopulations in the spleen and peripheral blood of turkeys and the effects of experimental immunodeficiency in the B and T cell compartments on the pathogenesis of hemorrhagic enteritis (HE) in turkeys. Inoculation of turkeys with hemorrhagic enteritis virus (HEV) induced a drop in the relative proportions of IgM bearing cells on Day 2, 3, and 9 post-infection and an elevation in the relative proportions of CD4 + cells on Day 4 and 6 post-infection. Elevated levels of CD8+ cells were observed in the infected turkeys only on Day 16 after infection. Marked depletion of IgM + cells may play a role in immunodepression caused by HEV. Cyclophosphamide (CY) treatment induced B cell deficiency in turkeys severely impaired HEV replication in the spleen suggesting that B lymphocytes are important for viral replication. Cyclosporin A (CsA) selectively impaired T cell mitogenesis and protected the turkeys against HEV-induced intestinal hemorrhages. CsA did not prevent viral replication in the spleen or the associated splenomegaly. This result suggested that T cell immunity may be important for intestinal hemorrhaging induced by HEV.

Haemochromatosis as a window into the study of the immunological system: a novel correlation between CD8+ lymphocytes and iron overload.

In the present study we report a serial investigation of the numbers of the peripheral blood cells--erythrocytes, polymorphonuclear neutrophils, total lymphocytes, T-lymphocyte subpopulations (CD2, CD4, CD8), B lymphocytes and monocytes--in a group of 21 patients with haemochromatosis during the time of intensive phlebotomy treatment, i.e., from iron overload until the onset of iron deficiency. A remarkable individual stability of all blood cell populations studied was found in all patients. Patients differed in their relative proportions of CD4+ and CD8+. Each individual's CD4/CD8 ratio, as well as the absolute numbers, remained unaffected with time, confirming the existence of a strict homeostatic regulation of the relative numbers of the two major peripheral T lymphocytes. A significant positive correlation between CD4/CD8 ratios and the amount of iron mobilised by phlebotomy was found during this study. A novel correlation between the relative proportions of CD4+ and CD8+ cells and iron overload is confirmed by the follow-up of iron re-entry in the serum transferrin pool in the treated patients.