Clinical efficacy of nivolumab is associated with tertiary lymphoid structures in surgically resected primary tumors of recurrent gastric cancer.

Nivolumab, an immune checkpoint blocker, has been approved for advanced gastric cancer (GC), but predictive factors of nivolumab's efficacy in patients with GC, especially immune cells such as tissue-resident memory T cells or those forming tertiary lymphoid structures (TLS), remain unclear. Tissue samples were obtained from surgically resected specimens of patients with GC who were treated with nivolumab as third-line or later treatment. Immunohistochemical staining was performed to detect the presence of TLS and CD103+ T cells and assess the association between TLSs and response to nivolumab treatment. A total of 19 patients were analyzed. In patients with partial response (PR) to nivolumab, numerous TLS were observed, and CD103+ T cells were found in and around TLS. Patients with many TLS experienced immune-related adverse events more often than those with few TLS (p = 0.018). The prognosis of patients with TLS high was better than those with TLS low. Patients with a combination of TLS high and CD103 high tended to have a better prognosis than other groups. Our results suggested that TLS status might be a predictor of nivolumab effectiveness.

Rapid Identification of the Tumor-Specific Reactive TIL Repertoire via Combined Detection of CD137, TNF, and IFNγ, Following Recognition of Autologous Tumor-Antigens.

Detecting the entire repertoire of tumor-specific reactive tumor-infiltrating lymphocytes (TILs) is essential for investigating their immunological functions in the tumor microenvironment. Current in vitro assays identifying tumor-specific functional activation measure the upregulation of surface molecules, de novo production of antitumor cytokines, or mobilization of cytotoxic granules following recognition of tumor-antigens, yet there is no widely adopted standard method. Here we established an enhanced, yet simple, method for identifying simultaneously CD8+ and CD4+ tumor-specific reactive TILs in vitro, using a combination of widely known and available flow cytometry assays. By combining the detection of intracellular CD137 and de novo production of TNF and IFNγ after recognition of naturally-presented tumor antigens, we demonstrate that a larger fraction of tumor-specific and reactive CD8+ TILs can be detected in vitro compared to commonly used assays. This assay revealed multiple polyfunctionality-based clusters of both CD4+ and CD8+ tumor-specific reactive TILs. In situ, the combined detection of TNFRSF9, TNF, and IFNG identified most of the tumor-specific reactive TIL repertoire. In conclusion, we describe a straightforward method for efficient identification of the tumor-specific reactive TIL repertoire in vitro, which can be rapidly adopted in most cancer immunology laboratories.

BAL biomarkers' panel for differential diagnosis of interstitial lung diseases.

Bronchoalveolar lavage (BAL) is a useful procedure for differential diagnosis of interstitial lung diseases (ILDs) and for identification of granulomatous lung diseases. We investigated a panel of biomarkers from BAL fluid of ILD patients to evaluate their utility in differentiating ILDs. Bronchoscopy with BAL was performed in 100 consecutive patients with suspected ILD (41 sarcoidosis, 11 cHP and 24 other ILDs); the 24 patients negative for ILD diagnosis were included as control group. BAL phenotypes and cell profiles (CD4+/CD8+ ratio, NK and CD103+ cell counts, chitotriosidase and KL-6 levels in BAL) were determined by flow cytometry. A decision-tree statistical algorithm was applied. Sarcoidosis was discriminated by a higher BAL CD4+/CD8+ ratio (p = 5.8E-05), a lower BAL CD103+CD4+ count (p = 5.0E-02) and lower BAL NK percentages (p = 8.8E-03) than the other groups. BAL KL-6 concentrations were higher in sarcoidosis than in other ILDs (p = 1.5E-02) and were directly correlated with CD4+/CD8+ ratio. We used decision-tree statistical analysis to combine our biomarkers into two diagnostic algorithms for differential diagnosis of ILDs. A panel of BAL biomarkers for diagnosis of ILDs is proposed; CD4+/CD8+ ratio, KL-6 concentrations, and NK and CD103+CD4+ cell percentages in BAL could improve the identification and differential diagnosis of sarcoidosis.

Integrin α11ß1 is expressed in breast cancer stroma and associates with aggressive tumor phenotypes.

Cancer-associated fibroblasts are essential modifiers of the tumor microenvironment. The collagen-binding integrin α11ß1 has been proposed to be upregulated in a pro-tumorigenic subtype of cancer-associated fibroblasts. Here, we analyzed the expression and clinical relevance of integrin α11ß1 in a large breast cancer series using a novel antibody against the human integrin α11 chain. Several novel monoclonal antibodies against the integrin α11 subunit were tested for use on formalin-fixed paraffin-embedded tissues, and Ab 210F4B6A4 was eventually selected to investigate the immunohistochemical expression in 392 breast cancers using whole sections. mRNA data from METABRIC and co-expression patterns of integrin α11 in relation to αSMA and cytokeratin-14 were also investigated. Integrin α11 was expressed to varying degrees in spindle-shaped cells in the stroma of 99% of invasive breast carcinomas. Integrin α11 co-localized with αSMA in stromal cells, and with αSMA and cytokeratin-14 in breast myoepithelium. High stromal integrin α11 expression (66% of cases) was associated with aggressive breast cancer features such as high histologic grade, increased tumor cell proliferation, ER negativity, HER2 positivity, and triple-negative phenotype, but was not associated with breast cancer specific survival at protein or mRNA levels. In conclusion, high stromal integrin α11 expression was associated with aggressive breast cancer phenotypes.

Prognostic significance of resident CD103+CD8+T cells in human colorectal cancer tissues.

The prognostic significance and clinical implications of resident CD103+CD8+T cells in human colorectal cancer tissues still remains largely unexplored. In our present study, we aimed to characterize the resident CD8+T cells in human colorectal cancer tissues by using double staining of CD103 and CD8, and further evaluated the prognostic significance of resident CD8+T cells in colorectal cancer. We found that the OS rate of the colorectal cancer patients with higher infiltration of CD8+T cells, or with higher numbers of resident CD103+CD8+T cells, or with higher ratio of CD103+CD8+T cells over total CD8+T cells in cancer tissues was significantly better than that of the patients with lower infiltration of CD8+T cells, or with lower numbers of resident CD103+CD8+T cells, or with higher ratio of CD103+CD8+T cells over total CD8+T cells in cancer tissues, respectively. Moreover, higher infiltration of CD8+T cells in colorectal cancer tissues was significantly and inversely correlated with advanced TNM stage. Higher numbers of resident CD103+CD8+T cells in colorectal cancer tissues were significantly and inversely correlated with distant metastasis status. Higher ratio of CD103+CD8+T cells over total CD8+T cells in colorectal cancer tissues was significantly and inversely correlated with age status. The COX model analysis demonstrated that higher infiltration of CD8+T cells, higher numbers of resident CD103+CD8+T cells, or higher ratio of CD103+CD8+T cells over total CD8+T cells in colorectal cancer tissues, could serve as independent prognostic predictors for colorectal cancer patients. Taken together, our present study demonstrated the density of tumor infiltrating CD8+T cells or the numbers of resident CD103+CD8+T cells in colorectal tissues could be used as an important prognostic predictor for this malignancy.

Altered Integrins Expression of Patients Affected by Cryptorchidism.

OBJECTIVES: The study aimed to investigate the expression of the integrin isoforms α7A and ß1A, expressed by myogenic precursor cells, and α7B and ß1D, expressed by mature muscle cells in the cremaster of patients affected by an undescended testis. METHODS: Fifteen samples of cremaster were obtained from patients undergoing surgery for an undescended testis. Thirty control specimens of cremaster were harvested from patients with congenital hydrocele or inguinal hernia. Immunofluorescent analysis was carried out using anti-α7A, ß1A, α7B, and ß1D integrin antibodies. Sections were observed using confocal laser scanning microscopy. RESULTS: As compared with controls, a significant loss of a α7B (p = 0.0355) and ß1D (p = 0.0069) integrins and a higher expression of α7A (p = 0.0003) and ß1A (p = 0.0150) was detected in the cremaster of patients affected by an undescended testis. CONCLUSIONS: Our data document a critical alteration of the cytoskeleton of cremasteric smooth muscle cells in patients with an undescended testis. This might explain the altered function in smooth muscle cells in cremaster implied during testicular descent. We therefore speculate that the postnatal splicing of α7A to α7B and of ß1A to ß1D integrins is delayed. This could account for the common clinical scenario of spontaneous descent of the testes in the first months of life.

Human Immunodeficiency Virus-Infected Women Have High Numbers of CD103-CD8+ T Cells Residing Close to the Basal Membrane of the Ectocervical Epithelium.

Background: Genital mucosa is the main portal of entry for various incoming pathogens, including human immunodeficiency virus (HIV), hence it is an important site for host immune defenses. Tissue-resident memory T (TRM) cells defend tissue barriers against infections and are characterized by expression of CD103 and CD69. In this study, we describe the composition of CD8+ TRM cells in the ectocervix of healthy and HIV-infected women. Methods: Study samples were collected from healthy Swedish and Kenyan HIV-infected and uninfected women. Customized computerized image-based in situ analysis was developed to assess the ectocervical biopsies. Genital mucosa and blood samples were assessed by flow cytometry. Results: Although the ectocervical epithelium of healthy women was populated with bona fide CD8+ TRM cells (CD103+CD69+), women infected with HIV displayed a high frequency of CD103-CD8+ cells residing close to their epithelial basal membrane. Accumulation of CD103-CD8+ cells was associated with chemokine expression in the ectocervix and HIV viral load. CD103+CD8+ and CD103-CD8+ T cells expressed cytotoxic effector molecules in the ectocervical epithelium of healthy and HIV-infected women. In addition, women infected with HIV had decreased frequencies of circulating CD103+CD8+ T cells. Conclusions: Our data provide insight into the distribution of CD8+ TRM cells in human genital mucosa, a critically important location for immune defense against pathogens, including HIV.

Immunohistochemical Detection of Hairy Cell Leukemia in Paraffin Sections: The Role of Pax5 and CD103 Double Staining to Improve Specificity and Sensitivity.

CONTEXT: - In hematopathology practice, abnormal expression of CD103 on B cells is detected by flow cytometry in hairy cell leukemia (HCL) and, in combination with other phenotypic and morphologic findings, provides diagnostic specificity and sensitivity. Immunostaining on paraffin sections makes it possible to perform immunophenotyping in situ. However, normal bone marrow contains CD103-positive cells, which are not B cells, making it difficult to be certain about low-level involvement by HCL. OBJECTIVE: - To develop dual immunostaining for confirmation that CD103 is expressed in B cells, which may be highly desirable in assessing low-level involvement by HCL. DESIGN: - We developed a dual immunostaining approach using a B-cell marker, Pax5, expressed in the nucleus, in combination with a membrane marker, CD103. RESULTS: - We analyzed 6 HCLs, 7 marginal zone lymphomas, 12 lymphoplasmacytic lymphomas, 7 follicular lymphomas, 5 chronic lymphocytic leukemias, 5 mantle cell lymphomas, 1 multiple myeloma (lymphocytic variant), and 3 bone marrows not involved by any B-cell neoplasm. Our dual staining approach confirmed that only the neoplastic cells of HCL were positive for both CD103 and Pax5. CONCLUSIONS: - This dual-staining method is particularly helpful in cases with low-level involvement by HCL and can be used for determining minimal residual disease after treatment.

Imaging of the cross-presenting dendritic cell subsets in the skin-draining lymph node.

Dendritic cells (DCs) are antigen-presenting cells specialized for activating T cells to elicit effector T-cell functions. Cross-presenting DCs are a DC subset capable of presenting antigens to CD8(+) T cells and play critical roles in cytotoxic T-cell-mediated immune responses to microorganisms and cancer. Although their importance is known, the spatiotemporal dynamics of cross-presenting DCs in vivo are incompletely understood. Here, we study the T-cell zone in skin-draining lymph nodes (SDLNs) and find it is compartmentalized into regions for CD8(+) T-cell activation by cross-presenting DCs that express the chemokine (C motif) receptor 1 gene, Xcr1 and for CD4(+) T-cell activation by CD11b(+) DCs. Xcr1-expressing DCs in the SDLNs are composed of two different populations: migratory (CD103(hi)) DCs, which immigrate from the skin, and resident (CD8α(hi)) DCs, which develop in the nodes. To characterize the dynamic interactions of these distinct DC populations with CD8(+) T cells during their activation in vivo, we developed a photoconvertible reporter mouse strain, which permits us to distinctively visualize the migratory and resident subsets of Xcr1-expressing DCs. After leaving the skin, migratory DCs infiltrated to the deep T-cell zone of the SDLNs over 3 d, which corresponded to their half-life in the SDLNs. Intravital two-photon imaging showed that after soluble antigen immunization, the newly arriving migratory DCs more efficiently form sustained conjugates with antigen-specific CD8(+) T cells than other Xcr1-expressing DCs in the SDLNs. These results offer in vivo evidence for differential contributions of migratory and resident cross-presenting DCs to CD8(+) T-cell activation.

Compartment-specific immunity in the human gut: properties and functions of dendritic cells in the colon versus the ileum.

OBJECTIVE: Dendritic cells (DC) mediate intestinal immune tolerance. Despite striking differences between the colon and the ileum both in function and bacterial load, few studies distinguish between properties of immune cells in these compartments. Furthermore, information of gut DC in humans is scarce. We aimed to characterise human colonic versus ileal DC. DESIGN: Human DC from paired colonic and ileal samples were characterised by flow cytometry, electron microscopy or used to stimulate T cell responses in a mixed leucocyte reaction. RESULTS: A lower proportion of colonic DC produced pro-inflammatory cytokines (tumour necrosis factor-α and interleukin (IL)-1ß) compared with their ileal counterparts and exhibited an enhanced ability to generate CD4(+)FoxP3(+)IL-10(+) (regulatory) T cells. There were enhanced proportions of CD103(+)Sirpα(-) DC in the colon, with increased proportions of CD103(+)Sirpα(+) DC in the ileum. A greater proportion of colonic DC subsets analysed expressed the lymph-node-homing marker CCR7, alongside enhanced endocytic capacity, which was most striking in CD103(+)Sirpα(+) DC. Expression of the inhibitory receptor ILT3 was enhanced on colonic DC. Interestingly, endocytic capacity was associated with CD103(+) DC, in particular CD103(+)Sirpα(+) DC. However, expression of ILT3 was associated with CD103(-) DC. Colonic and ileal DC differentially expressed skin-homing marker CCR4 and small-bowel-homing marker CCR9, respectively, and this corresponded to their ability to imprint these homing markers on T cells. CONCLUSIONS: The regulatory properties of colonic DC may represent an evolutionary adaptation to the greater bacterial load in the colon. The colon and the ileum should be regarded as separate entities, each comprising DC with distinct roles in mucosal immunity and imprinting.

A novel kefir product (PFT) activates dendritic cells to induce CD4+T and CD8+T cell responses in vitro.

Lactobacilli have been widely studied for their probiotic effects and have been reported to function as antiviral and anticancer agents. However, the underlying mechanisms via immune modulation are poorly understood. PFT is a freeze dried compound of Lactobacillus kefiri P-IF with a unique composition and functionality. In this study, we examined the potential stimulatory effects of two concentrations (50 µg and 100 µg/mL) of PFT on human monocyte-derived dendritic cell (DC) function in vitro. Results showed that PFT upregulated the expression of DC surface co-stimulatory and maturation markers CD80, CD86, and HLADR in a concentration dependent manner. PFT at 100 µg/mL markedly increased the secretion of IL-6, IL-10, TNF-α, and IL-1ß by DCs. This concentration of PFT also stimulated the production of antiviral cytokines, IFN-α and IFN-λ(IL29) in DCs. Additionally, PFT at 100 µg/mL activated moDCs prime CD4(+)T cells and significantly increased the levels of IL-10, IFN-γ, and TNF-α by 1.7, four, three-fold, respectively. Furthermore PFT-stimulated DCs were also effective in enhancing the cytotoxic potential of CD8(+)T cells via the induction of Granzyme-B and upregulation of CD107a, and CD103 expression, a marker of resident/regulatory CD8(+)T cells. These data suggest that PFT functions as a natural adjuvant for DC activation and thus may be used in DC-based vaccine strategies against viral infections and cancer.

CD103+ γδ T cell large granular lymphocytosis in a patient with refractory celiac disease: a diagnostic enigma.

Indolent γδ T cell lymphomas/leukemias are rare and overlap with the morphological spectrum of large granular lymphocyte (LGL) leukemia. We report an extremely rare case of CD103(+) γδ T LGL leukemia in a patient with celiac disease who presented with refractory diarrhea. Whether the refractory diarrhea in our patient was a manifestation of LGL leukemia itself or whether the clonal LGL expansion is a manifestation of refractory celiac disease (RCD) remains an enigma. This report highlights the diagnostic difficulties and the need of consensus in categorizing clonal CD103(+) lymphocytosis in patients with RCD.

Selective and efficient generation of functional Batf3-dependent CD103+ dendritic cells from mouse bone marrow.

Multiple subsets of FMS-like tyrosine kinase 3 ligand (FLT3L)-dependent dendritic cells (DCs) control T-cell tolerance and immunity. In mice, Batf3-dependent CD103(+) DCs efficiently enter lymph nodes and cross-present antigens, rendering this conserved DC subset a promising target for tolerance induction or vaccination. However, only limited numbers of CD103(+) DCs can be isolated with current methods. Established bone marrow culture protocols efficiently generate monocyte-derived DCs or produce a mixture of FLT3L-dependent DC subsets. We show that CD103(+) DC development requires prolonged culture time and continuous action of both FLT3L and granulocyte macrophage colony-stimulating factor (GM-CSF), explained by a dual effect of GM-CSF on DC precursors and differentiating CD103(+) DCs. Accordingly, we established a novel method to generate large numbers of CD103(+) DCs (iCD103-DCs) with limited presence of other DC subsets. iCD103-DCs develop in a Batf3- and Irf8-dependent fashion, express a CD8α/CD103 DC gene signature, cross-present cell-associated antigens, and respond to TLR3 stimulation. Thus, iCD103-DCs reflect key features of tissue CD103(+) DCs. Importantly, iCD103-DCs express high levels of CCR7 upon maturation and migrate to lymph nodes more efficiently than classical monocyte-derived DCs. Finally, iCD103-DCs induce T cell-mediated protective immunity in vivo. Our study provides insights into CD103(+) DC development and function.

Profile of CD103 expression in T-cell neoplasms: immunoreactivity is not restricted to enteropathy-associated T-cell lymphoma.

Intestinal intraepithelial T lymphocytes express the α E subunit of integrin αEß7, which is detected by antibodies to CD103. Accordingly, within T-cell neoplasms, CD103 reactivity has most frequently been reported in enteropathy-associated T-cell lymphomas, which are postulated to arise from intestinal intraepithelial T lymphocytes. However, prior studies of CD103 expression in T-cell neoplasms have been limited by the requirement for fresh or frozen tissue, given the historic lack of an antibody to CD103 for use in paraffin-embedded sections. Thus, a thorough assessment of CD103 expression in a broad spectrum of T-cell neoplasms as categorized by the current classification system has not yet been performed. This study uses a newly described antibody to define the profile of CD103 immunoreactivity in paraffin sections of a wide variety of T-cell neoplasms (184 cases). Overall, 22 T-cell neoplasms (12%) were CD103 positive, including 7 of 15 gastrointestinal lymphomas (3.8% of total cases; 46% of gastrointestinal cases). In intestinal cases, CD103 positivity did not correlate with morphology, presence or absence of enteropathy, or immunohistochemical profile. A history of celiac disease was not documented in any case. Frequent but inconsistent reactivity was also noted for adult T-cell leukemia/lymphoma with 4 of 10 cases (40%) positive. In the remaining T-cell neoplasms representing most entities within the current World Health Organization classification, CD103 reactivity was sporadically observed in 11 of 159 cases (6.9%). CD103 positivity is an unusual feature in T-cell neoplasms and tends to occur in gastrointestinal lymphomas and adult T-cell leukemia/lymphoma but is not a consistent characteristic of these neoplasms.

Control of T cell fates and immune tolerance by p38α signaling in mucosal CD103+ dendritic cells.

Dendritic cells (DCs) play a crucial role in launching protective adaptive immunity against pathogens while maintaining immune tolerance to self-Ags. However, how intracellular signaling pathways program DCs to mediate tolerogenic responses remains largely unexplored. In this study, we describe that p38α signaling in CD103(+) mesenteric lymph node DCs reciprocally regulates the differentiation of anti-inflammatory induced regulatory T cells and proinflammatory Th1 cells from naive precursors and promotes mucosal tolerance. Deficiency of p38α in CD103(+) DCs inhibited the generation of induced regulatory T cells while promoting Th1 cell development in a TGF-ß2-dependent manner. Consequently, loss of p38α in DCs prevented induction of oral tolerance in vivo. Moreover, p38α in CD103(+) DCs was required for optimal expression of retinaldehyde dehydrogenase, a key enzyme for retinoic acid synthesis, which in turn imprinted gut-homing receptors on responding T cells. Consistent with a crucial role of p38α to program the tolerogenic activity of CD103(+) DCs, such DC subset contained constitutive activity of p38α and abundant expression of TGF-ß2 and retinaldehyde dehydrogenase. Our studies identify a key mechanism of DC-mediated coupling of T cell differentiation and trafficking that orchestrates mucosal immune tolerance.

Site-specific dynamics of CD11b+ and CD103+ dendritic cell accumulations following ozone exposure.

Pulmonary dendritic cells (DCs) are among the first responders to inhaled environmental stimuli such as ozone (O(3)), which has been shown to activate these cells. O(3) reacts with epithelial lining fluid (ELF) components in an anatomically site-specific manner dictated by O(3) concentration, airway flow patterns, and ELF substrate concentration. Accordingly, the anatomical distribution of ELF reaction products and airway injury are hypothesized to produce selective DC maturation differentially within the airways. To investigate how O(3) affects regional airway DC populations, we utilized a model of O(3)-induced pulmonary inflammation, wherein C57BL/6 mice were exposed to 0.8 ppm O(3) 8 h/day for 1, 3, and 5 days. This model induced mild inflammation and no remarkable epithelial injury. Tracheal, but not more distant airway sites, and mediastinal lymph node (MLN) DC numbers were increased significantly after the third exposure day. The largest increase in each tissue was of the CD103(+) DC phenotype. After 3 days of exposure, fewer DCs expressed CD80, CD40, and CCR7, and, at this same time point, total MLN T cell numbers increased. Together, these data demonstrate that O(3) exposure induced site-specific and phenotype changes in the pulmonary and regional lymph node DC populations. Possibly contributing to ozone-mediated asthma perturbation, the phenotypic changes to DCs within pulmonary regions may alter responses to antigenic stimuli. Decreased costimulatory molecule expression within the MLN suggests induction of tolerance mechanisms; increased tracheal DC number may raise the potential for allergic sensitization and asthmatic exacerbation, thus overcoming O(3)-induced decrements in costimulatory molecule expression.

Alveolar epithelial cells orchestrate DC function in murine viral pneumonia.

Influenza viruses (IVs) cause pneumonia in humans with progression to lung failure. Pulmonary DCs are key players in the antiviral immune response, which is crucial to restore alveolar barrier function. The mechanisms of expansion and activation of pulmonary DC populations in lung infection remain widely elusive. Using mouse BM chimeric and cell-specific depletion approaches, we demonstrated that alveolar epithelial cell (AEC) GM-CSF mediates recovery from IV-induced injury by affecting lung DC function. Epithelial GM-CSF induced the recruitment of CD11b+ and monocyte-derived DCs. GM-CSF was also required for the presence of CD103+ DCs in the lung parenchyma at baseline and for their sufficient activation and migration to the draining mediastinal lymph nodes (MLNs) during IV infection. These activated CD103+ DCs were indispensable for sufficient clearance of IVs by CD8+ T cells and for recovery from IV-induced lung injury. Moreover, GM-CSF applied intratracheally activated CD103+ DCs, inducing increased migration to MLNs, enhanced viral clearance, and attenuated lung injury. Together, our data reveal that GM-CSF-dependent cross-talk between IV-infected AECs and CD103+ DCs is crucial for effective viral clearance and recovery from injury, which has potential implications for GM-CSF treatment in severe IV pneumonia.

IL-10 deficiency blocks the ability of LPS to regulate expression of tolerance-related molecules on dendritic cells.

Interleukin-10 (IL-10) is an anti-inflammatory cytokine that plays an important role in regulating the local inflammatory immune response, but regulatory mechanisms of this cytokine have not been fully elucidated. Here, we demonstrate that IL-10 deficiency renders LPS treatment ineffective in regulating the expression of CD40, CD80, CD86, B7-H2, and B7-DC on dendritic cells (DCs) and blocks upregulation of IL-27. This inability to respond to LPS was found in both IL-10(-/-) bone marrow derived and splenic DCs. Compared with wild-type DCs, IL-10(-/-) DCs expressed similar levels of TLR4 and CD14, but produced less LPS-binding protein. The deficiency in LPS-binding protein production may explain the failure of IL-10(-/-) DCs to respond normally to LPS. Moreover, lack of IL-10 modulated the proportions of CD11c(+) CD8(+) and CD11c(+) B220(+) DCs, which play an important role in local inflammatory responses and tolerance. IL-10 deficiency also blocked expression of galectin-1, CD205, and CD103, which are necessary for central and peripheral tolerance. While they did not respond to LPS, IL-10(-/-) DCs produced increased levels of IL-6 and CCL4 after TNF-α treatment. Together, our results demonstrate that IL-10 deficiency affects the immune functions of DCs, which may contribute to the increased severity of autoimmune diseases seen in IL-10(-/-) mice.

Failure to recruit anti-inflammatory CD103+ dendritic cells and a diminished CD4+ Foxp3+ regulatory T cell pool in mice that display excessive lung inflammation and increased susceptibility to Mycobacterium tuberculosis.

Susceptibility to Mycobacterium tuberculosis is characterized by excessive lung inflammation, tissue damage, and failure to control bacterial growth. To increase our understanding of mechanisms that may regulate the host immune response in the lungs, we characterized dendritic cells expressing CD103 (α(E) integrin) (αE-DCs) and CD4(+) Foxp3(+) regulatory T (T(reg)) cells during M. tuberculosis infection. In resistant C57BL/6 and BALB/c mice, the number of lung αE-DCs increased dramatically during M. tuberculosis infection. In contrast, highly susceptible DBA/2 mice failed to recruit αE-DCs even during chronic infection. Even though tumor necrosis factor alpha (TNF-α) is produced by multiple DCs and macrophage subsets and is required for control of bacterial growth, αE-DCs remained TNF-α negative. Instead, αE-DCs contained a high number of transforming growth factor beta-producing cells in infected mice. Further, we show that T(reg) cells in C57BL/6 and DBA/2 mice induce gamma interferon during pulmonary tuberculosis. In contrast to resistant mice, the T(reg) cell population was diminished in the lungs, but not in the draining pulmonary lymph nodes (PLN), of highly susceptible mice during chronic infection. T(reg) cells have been reported to inhibit M. tuberculosis-specific T cell immunity, leading to increased bacterial growth. Still, despite the reduced number of lung T(reg) cells in DBA/2 mice, the bacterial load in the lungs was increased compared to resistant animals. Our results show that αE-DCs and T(reg) cells that may regulate the host immune response are increased in M. tuberculosis-infected lungs of resistant mice but diminished in infected lungs of susceptible mice.

Characteristic CD103 and CD123 expression pattern defines hairy cell leukemia: usefulness of CD123 and CD103 in the diagnosis of mature B-cell lymphoproliferative disorders.

By using flow cytometry, we studied CD103 and CD123 expression by the malignant cells in 300 B-cell lymphoproliferative disorder (BC-LPD) cases, including 114 hairy cell leukemia (HCL), 20 HCL variant (HCLv), 9 splenic marginal zone lymphoma (SMZL; in 5, only CD103 was evaluated), 133 chronic lymphocytic leukemia (CLL), 3 follicular lymphoma (FL), and 21 mantle cell lymphoma (MCL). All HCLs expressed uniform CD103 and bright CD123. Among the 20 HCLv cases, 20 (100%) were CD103+ and 8 (40%) were CD123+ (partial or dim). CD103 was negative in all MCL, FL, CLL, and SMZL cases. CD123 was positive in 1 (25%) of 4 SMZL, 3.8% of CLL (5/133), 7 (33%) of 21 MCL, and 1 (33%) of 3 FL cases. CD103 is specific for HCL and HCLv. CD123 expression is more widespread in BC-LPDs but is useful in conjunction with CD25 to differentiate HCLv from HCL. These findings support the usefulness of CD123 and CD103 to aid in the differential diagnosis of BC-LPDs.