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Abstract
Intraepithelial lymphocytes (IELs) contain several subsets, but the origin of the T-cell receptor (TCR)alphabeta(+) CD8 alpha alpha(+) IELs has been particularly controversial. Here we provide a synthesis, based on recent work, that attempts to unify the divergent views. The intestine has a primordial function in lymphopoiesis, and precursors with the potential to differentiate into T cells are found both in the epithelium and underlying lamina propria. Moreover, the thymus has been reported to export cells to the intestine that are not fully differentiated. TCR alpha beta(+) CD8 alpha alpha(+) IELs can differentiate in the intestine from each of these sources, but in normal euthymic mice, the thymus appears to be the major source for TCR alpha beta(+) CD8 alpha alpha(+) IELs. This unique IEL subset is a self-reactive population that requires exposure to self-agonists for selection in the thymus, similar to other regulatory T-cell populations. IELs transition through a double-positive (DP) intermediate in the thymus, but they originate from a subset of the DP cells that can be identified by its expression of CD8 alpha alpha homodimers. The agonist-selected cells in the thymus are TCRbeta(+) but CD4 and CD8 double negative. The evidence suggests that reacquired expression of CD8 alpha alpha and downregulation of CD5 occur after thymus export, perhaps in the intestine under the influence of interleukin-15. As a result of agonist exposure, a new gene expression program is activated. Therefore, the increased understanding of the developmental origin of TCR alpha beta(+) CD8 alpha alpha(+) IELs may help us to understand how they participate in immune regulation and protection in the intestine.
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Affiliation(s)
- Florence Lambolez
- Division of Developmental Immunology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037, USA
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52
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Centlivre M, Sala M, Wain-Hobson S, Berkhout B. In HIV-1 pathogenesis the die is cast during primary infection. AIDS 2007; 21:1-11. [PMID: 17148962 DOI: 10.1097/qad.0b013e3280117f7f] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The chronic stage of HIV-1 infection has been extensively described as a slowly evolving phase, in which the virus induces T-cell death slightly faster than the human body is able to recover. In contrast, T-cell and viral replication dynamics during primary infection have been less well studied. Recent studies in the SIV-macaque model and in HIV-positive patients during the acute infection period have highlighted the massive and irreversible depletion of CD4 memory T cells in the mucosa, particularly in the gut. Hence, gut-associated lymphoid tissue (GALT) plays a central role in the early stages of HIV-1 pathogenesis. Due to its particular cytokine expression pattern, GALT may favour the differential replication of certain HIV-1 subtypes during primary infection, particularly of subtype C. This could enhance the chance of a successful transmission. Moreover, these early events taking place in GALT during primary infection have major implications for therapy and vaccine design.
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53
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Davenport V, Groves E, Hobbs CG, Williams NA, Heyderman RS. Regulation of Th-1 T cell-dominated immunity to Neisseria meningitidis within the human mucosa. Cell Microbiol 2006; 9:1050-61. [PMID: 17166235 DOI: 10.1111/j.1462-5822.2006.00851.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Neisseria meningitidis is commonly carried asymptomatically in the upper respiratory tract and only occasionally invades the bloodstream and meninges to cause disease. Naturally acquired immunity appears protective but the nature of the cellular immune response within the mucosa is uncertain. We show that following in vitro stimulation with N. meningitidis serogroup B (MenB) antigens, approximately 66% of the dividing mucosal CD4(+)CD45RO(+) memory population express the Th1-associated IL18-R while the remainder express CRTH2, a Th2-associated marker. The pro-inflammatory bias of this anti-MenB response is not evident in blood, demonstrating compartmentalization at the induction site; and occurs in the presence or absence of lipopolysacharide indicating that these responses are already fully committed. Depletion of CD25(+) cells reveals suppression of the effector CD4(+) T cell response restricted to the mucosa and most marked in children (i.e. those at greatest risk of disease). Mucosal T-regulatory cell (Treg) activity is partially overcome by blocking the human glucocorticoid-induced TNF receptor (GITR) and is not seen following stimulation with antigens from another mucosal pathogen, influenza virus. Pro-inflammatory, antimeningococcal T cell responses may limit invasive disease at the mucosa but Treg induction while reducing immunopathological damage, may also restrict the effectiveness of the protective response, particularly in children.
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Affiliation(s)
- Victoria Davenport
- Department of Cellular and Molecular Medicine, School of Medical Sciences, University of Bristol, University Walk, Bristol, UK
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54
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Suzuki K, Ha SA, Tsuji M, Fagarasan S. Intestinal IgA synthesis: a primitive form of adaptive immunity that regulates microbial communities in the gut. Semin Immunol 2006; 19:127-35. [PMID: 17161619 DOI: 10.1016/j.smim.2006.10.001] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2006] [Accepted: 10/26/2006] [Indexed: 12/25/2022]
Abstract
Our intestine is colonized by an impressive community of bacteria, that has profound effects on the immune functions. The relationship between gut microbiota and the immune system is one of reciprocity: bacteria have important contribution in nutrient processing and education of the immune system and conversely, the immune system, particularly gut-associated lymphoid tissues (GALT) plays a key role in shaping the repertoire of gut microbiota. In this review we discuss new insights into the role of IgA in the maintenance of immune homeostasis and the reciprocal interactions between gut B cells and intestinal bacteria.
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Affiliation(s)
- Keiichiro Suzuki
- RIKEN Research Center for Allergy and Immunology, Mucosal Immunity Laboratory, Yokohama, Kanagawa 230-0045, Japan
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55
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Becker Y. The spreading of HIV-1 infection in the human organism is caused by fractalkine trafficking of the infected lymphocytes—a review, hypothesis and implications for treatment. Virus Genes 2006; 34:93-109. [PMID: 17151939 DOI: 10.1007/s11262-006-0056-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The reviews on HIV-1/AIDS [1-8] highlighted the mechanism by which HIV-1 virions utilize dendritic cells (DCs) for transport from the genitals, the portal of virus infection, to the draining lymph nodes where DCs carry HIV-1 virions and present viral antigens by HLA class I and II to CD4(+) T cells. Interaction of the T cells with viral antigens presented by HLA class II molecules polarizes them to become Th2 cells, the targets of HIV-1 infection and producers of HIV-1 progeny virions. The T cells which interact with viral antigen presented by HLA class I polarize to become Th1 cells, which stimulate the CD8(+) T cell precursors to develop into antiviral cytotoxic T cells. In addition, HIV-1 virions shed gp120 glycoprotein molecules which bind to IgE immunoglobulin molecules bound to FCepsilonRI+ innate system cells (basophils, mast cells and monocytes) and induce them to release large amounts of Th2 cytokines (IL-4, IL-5, IL-10, IL-13), thereby creating an allergy-like condition. The present review attempts to define the role of chemokine receptors like CCR5 and CXCR4, and especially fractalkine receptor CX3CR1 in the trafficking of lymphocytes in healthy individuals and HIV-1/AIDS patients. The role of chemokine receptors as co-receptors for HIV-1 virion gp120 glycoprotein has been defined, but the role of fractalkine and fractalkine receptor has been clarified only recently [9-19]. In healthy individuals fractalkine is expressed by blood vessel endothelial cells and the CX3CR1 receptors are expressed on leukocytes that migrate in the peripheral blood in the direction of increased fractalkine concentration. In HIV-1/AIDS patients the virus-infected CD4(+) Th2 cells migrate to organs that harbor the adaptive immune system cells in the thymus, genitals, gastrointestinal tract, and to the brain. A most significant finding which revealed the importance of the human CX3CR1 gene expression to the progression of the infection to the stage of AIDS was recently reported by Faure and collaborators [20, 21] who showed that the delayed or rapid progression to AIDS was affected in HIV-1-infected individuals who had inherited a fractalkine receptor gene with the polymorphisms V249I or T280M, respectively, located in the sixth and seventh transmembrane domains of CX3CR1 protein. The T280M mutation in the CX3CR1 gene caused a rapid progression to AIDS, while in patients with the V249I mutation progression to AIDS was much slower. These studies led to the idea that it might be possible to slow or prevent HIV-1/AIDS progression in HIV-1 patients by treating them with fractalkine antagonists that will bind to and inhibit the activity of the fractalkine receptor. It is hypothesized that treatment of HIV-1/AIDS patients with a combination of fractalkine antagonists, IL-4 antagonist IL-4delta2 and the adjuvant CpG ODN induced release of type I IFN from PDF, and may inhibit HIV-1 infection, especially in HAART-treated patients infected with drug-resistant HIV-1 mutants due to prevention of the availability of immune cells needed for the viral evasion of the immune response. The hypothesis implies that the advantage of the suggested mode of treatment of HIV-1-infected people is prevention of cellular processes that are used by the viral protein to cause immunodeficiency, and prevention of HIV-1 replication without induction of resistant mutants.
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Affiliation(s)
- Yechiel Becker
- Department of Molecular Virology, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel.
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56
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Lin SW, Cun AS, Harris-McCoy K, Ertl HC. Intramuscular rather than oral administration of replication-defective adenoviral vaccine vector induces specific CD8+ T cell responses in the gut. Vaccine 2006; 25:2187-93. [PMID: 17229501 PMCID: PMC1839821 DOI: 10.1016/j.vaccine.2006.11.044] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2006] [Revised: 11/16/2006] [Accepted: 11/21/2006] [Indexed: 11/17/2022]
Abstract
Gut-associated lymphoid tissue (GALT) is the primary replication site for HIV-1, resulting in a pronounced CD4(+) T cell loss in this tissue during primary infection. A mucosal vaccine that generates HIV-specific CD8(+) T cells in the gut could prevent the establishment of founder populations and broadcasting of virus. Here, we immunized mice orally and systemically with a chimpanzee derived adenoviral vector expressing HIV gag (AdC68gag) and measured frequencies of gag-specific interferon-gamma (IFN-gamma) producing CD8(+) T cells in the GALT. A single oral administration was inefficient at eliciting responses in the mesenteric lymph nodes and Peyer's Patches, while a single intramuscular administration elicited strong systemic and detectable mucosal responses. The gag-specific CD8(+) T cell responses were present in both acute and memory phases following intramuscular administration.
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Affiliation(s)
- S W Lin
- School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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57
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58
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Tsujimura K, Obata Y, Matsudaira Y, Nishida K, Akatsuka Y, Ito Y, Demachi-Okamura A, Kuzushima K, Takahashi T. Characterization of murine CD160+ CD8+ T lymphocytes. Immunol Lett 2006; 106:48-56. [PMID: 16764942 DOI: 10.1016/j.imlet.2006.04.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2006] [Revised: 04/21/2006] [Accepted: 04/23/2006] [Indexed: 01/09/2023]
Abstract
CD160 is an Ig-like glycoprotein expressed on NK, NKT and TCRgammadelta T cells, as well as intestinal intraepithelial T lymphocytes. In addition, a minor subset of CD8(+) but not CD4(+) T cells in the periphery is also known to express CD160, but the subset has not been fully characterized. In this study, we prepared anti-murine CD160 mAbs and investigated the expression profile of CD160 on various subsets of CD8(+) T cells. The amount of CD160 on almost all CD8(+) T cells was increased upon CD3-mediated stimulation in vitro, and soluble CD160 was found to be released. Flow cytometric analysis revealed most CD8(+) T cells expressing CD160 to show a CD44(high) phenotype in vivo. On further analysis, both CD44(high)CD62L(low) effector memory T cells (T(EM)) and CD44(high)CD62L(high) central memory T cells (T(CM)) expressed CD160 at an intermediate level. High levels were evident with recently activated CD8(+) T(EM). Naïve CD8(+) T cells presumably immediately after stimulation (CD44(low)CD62L(low)CD69(+)) also expressed CD160, but only at a low level. Purified CD160(+) CD8(+) T cells from OT-1 transgenic mice expressing TCR against OVA residues 257-264 presented by H-2K(b) produced IFN-gamma more rapidly than CD160(-) CD8(+) T cells upon antigen stimulation. These results together show that CD160 is expressed on the majority of CD8(+) memory T cells as well as recently activated CD8(+) T cells.
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Affiliation(s)
- Kunio Tsujimura
- Division of Immunology, Aichi Cancer Center Research Institute, Nagoya, Japan.
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59
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Giacalone MJ, Sabbadini RA, Chambers AL, Pillai S, McGuire KL. Immune responses elicited by bacterial minicells capable of simultaneous DNA and protein antigen delivery. Vaccine 2006; 24:6009-17. [PMID: 16806602 PMCID: PMC7125846 DOI: 10.1016/j.vaccine.2006.04.063] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2006] [Revised: 04/14/2006] [Accepted: 04/20/2006] [Indexed: 11/22/2022]
Abstract
Recent events surrounding emerging infectious diseases, bioterrorism and increasing multidrug antibiotic resistance in bacteria have drastically increased current needs for effective vaccines. Many years of study have shown that live, attenuated pathogens are often more effective at delivering heterologous protein or DNA to induce protective immune responses. However, these vaccine carriers have inherent safety concerns that have limited their development and their use in many patient populations. Studies using nonliving delivery mechanisms have shown that providing both protein antigen and DNA encoding the antigen to an individual induces an improved, more protective immune response but rarely, if ever, are both delivered simultaneously. Here, non-replicating bacterial minicells derived from a commensal E. coli strain are shown to effectively induce antigen-specific immune responses after simultaneous protein and DNA delivery. These data demonstrate the potential use of achromosomal bacterial minicells as a vaccine carrier.
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Affiliation(s)
| | - Roger A. Sabbadini
- The Molecular Biology Institute, San Diego State University, San Diego, CA, USA
- Department of Biology, Center For Microbial Sciences, San Diego State University, San Diego, CA, USA
| | - Amy L. Chambers
- The Molecular Biology Institute, San Diego State University, San Diego, CA, USA
| | - Sabitha Pillai
- The Molecular Biology Institute, San Diego State University, San Diego, CA, USA
| | - Kathleen L. McGuire
- The Molecular Biology Institute, San Diego State University, San Diego, CA, USA
- Department of Biology, Center For Microbial Sciences, San Diego State University, San Diego, CA, USA
- Corresponding author at: Department of Biology, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-4614, USA. Tel.: +1 619 594 7191; fax: +1 619 594 5676.
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60
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Centlivre M, Sommer P, Michel M, Ho Tsong Fang R, Gofflo S, Valladeau J, Schmitt N, Wain-Hobson S, Sala M. The HIV-1 clade C promoter is particularly well adapted to replication in the gut in primary infection. AIDS 2006; 20:657-66. [PMID: 16514295 DOI: 10.1097/01.aids.0000216365.38572.2f] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
OBJECTIVE Coinfection of rhesus macaques with human/simian immunodeficiency virus chimeras harbouring the minimal core-promoter/enhancer elements from HIV-1 clade B, C and E viral prototypes (STR-B, STR-C and STR-E) revealed a remarkable dichotomy in terms of spatio-temporal viral replication. The clade C chimera (STR-C) predominated in primary infection. The present study was aimed at identifying the origin of STR-C plasma viraemia at this infection phase. DESIGN By competing isogenic viruses differing only in their promoters, it was possible to identify subtle phenotypical differences in viral replication kinetics and compartmentalization in vivo. METHODS Two rhesus macaques were coinfected by the three STR chimeras and the relative colonization of different compartments, particularly blood and stool, was determined for each chimera. Moreover, growth competition experiments in thymic histocultures enriched in interleukin (IL)-7 were performed and relative percentages of chimeras were estimated in supernatants and thymocytes lysates at different time points. RESULTS It is demonstrated here that at the peak of primary infection, preferential replication of STR-C was supported by the gut-associated lymphoid tissue (GALT), an IL-7 rich microenvironment. This was shown by the correlation of the RNA viral genotype in blood and stools, compartments directly draining virions from the GALT. Thymic histocultures confirmed that replication of STR-C is particularly susceptible to this cytokine, compared to its STR-B and STR-E counterparts. CONCLUSIONS These data show that the GALT cytokine network may well favour HIV-1 clade C replication during primary infection. This could result in enhanced transmission.
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61
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Koutsos E, Arias V. Intestinal Ecology: Interactions Among the Gastrointestinal Tract, Nutrition, and the Microflora. J APPL POULTRY RES 2006. [DOI: 10.1093/japr/15.1.161] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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62
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Santana MA, Esquivel-Guadarrama F. Cell biology of T cell activation and differentiation. INTERNATIONAL REVIEW OF CYTOLOGY 2006; 250:217-74. [PMID: 16861067 DOI: 10.1016/s0074-7696(06)50006-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
T cells are major components of the adaptive immune system. They can differentiate into two different populations of effector cells-type one and type two-and may also become tolerant. T cells respond to immune challenges by interacting with antigen-presenting cells of the innate immune system. These latter cells can identify the nature of any immune challenge and initiate adaptive immune responses. Dendritic cells are the most important antigen-presenting cells in the body. The T cell recognizes both peptides associated with MHC molecules on the antigen-presenting cells and also other molecules in a complex structure known as an immunological synapse. The nature of the antigen, the cytokine environment, and other molecules on the dendritic cell surface instruct the T cells as to the response required. A better understanding of the biology of T cell responses offers the prospect of more effective therapeutic interventions.
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Affiliation(s)
- María Angélica Santana
- Faculty of Sciences, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, Mexico
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63
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Abstract
The intestinal intraepithelial lymphocytes (IELs) are mostly T cells dispersed as single cells within the epithelial cell layer that surrounds the intestinal lumen. IELs are, therefore, strategically located at the interface between the antigen-rich outside world and the sterile core of the body. The intestine of higher vertebrates has further evolved to harbor numerous commensal bacteria that carry out important functions for the host, and while defensive immunity can effectively protect against the invasion of pathogens, similar immune reactions against food-derived antigens or harmless colonizing bacteria can result in unnecessary and sometimes damaging immune responses. Probably as a result of this unique dilemma imposed by the gut environment, multiple subsets of IEL have differentiated, which all display characteristics of 'activated yet resting' immune cells. Despite this common feature, IELs are heterogeneous with regard to their phenotype, ontogeny, and function. In this review, we discuss the different subtypes of IELs and highlight the distinct pathways they took that led to their unique differentiation into highly specialized effector memory T cells, which provide the most effective immune protection yet in a strictly regulated fashion to preserve the integrity and vital functions of the intestinal mucosal epithelium.
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Affiliation(s)
- Hilde Cheroutre
- The La Jolla Institute for Allergy and Immunology, San Diego, CA 92121, USA.
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64
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Roth-Walter F, Bohle B, Schöll I, Untersmayr E, Scheiner O, Boltz-Nitulescu G, Gabor F, Brayden DJ, Jensen-Jarolim E. Targeting antigens to murine and human M-cells with Aleuria aurantia lectin-functionalized microparticles. Immunol Lett 2005; 100:182-8. [PMID: 15913790 DOI: 10.1016/j.imlet.2005.03.020] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2005] [Accepted: 03/30/2005] [Indexed: 10/25/2022]
Abstract
Neuraminidases act as a virulence factors for several pathogens that invade the human body through Peyer's patch M-cells. Because of the structural similarity of Aleuria aurantia lectin (AAL) to neuraminidases, we hypothesized that AAL might also target human M-cells. In an in vitro human M-cell co-culture model significantly more particles were transported across the epithelium when microparticles were functionalized with AAL versus those that were not. Moreover, high concentrations of AAL induced no detectable cytotoxic effects on the related intestinal epithelial cell cultures, epithelial Caco2- and HT29-MTX-E12-cells. Upon incubation with AAL, PBMCs of allergic volunteers proliferated in response to AAL and secreted the cytokines, IL-2, IFN-gamma, IL-10 and IL-5 in a concentration-dependent manner, indicating immune-stimulatory properties of the lectin. We conclude that AAL-coated microparticles may have the potential to target entrapped antigens to human M-cells for oral vaccination.
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Affiliation(s)
- Franziska Roth-Walter
- Center of Physiology and Pathophysiology, Medical University of Vienna, AKH-3Q, Waehringer Guertel 18-20, A-1090 Vienna, Austria
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65
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Chang F, Mahadeva U, Deere H. Pathological and clinical significance of increased intraepithelial lymphocytes (IELs) in small bowel mucosa. APMIS 2005; 113:385-99. [PMID: 15996156 DOI: 10.1111/j.1600-0463.2005.apm_204.x] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Intestinal intraepithelial lymphocytes (IELs) belong to a unique T-cell population interspersed between epithelial cells of both the small and large intestine. It is becoming increasingly recognised that an increased number of IELs with a normal villous architecture is within the wide spectrum of histological abnormalities observed in coeliac disease. An increased number of IELs is the earliest pathological change following gluten challenge and a high IEL count may be the only sign of gluten sensitivity. Therefore, the finding of a raised IEL count with normal villous architecture is of sufficient clinical importance to be reported in routine small bowel biopsies. However, it is evident that not all small intestinal biopsy specimens showing increased IELs are explained by gluten sensitivity. Increased IELs in small bowel mucosa have also been associated with autoimmune disorders, tropical sprue, food protein intolerance, Helicobacter pylori-associated gastritis, peptic duodenitis, parasitic and viral infections, as well as the development of intestinal lymphoma. Histological examination of a biopsy specimen of the small bowel remains the diagnostic gold standard for coeliac disease. There will be an ever increasing demand for histological confirmation of gluten sensitivity in patients in whom the classic microscopic appearance of flattened villi may not have fully developed. The more widespread recognition by histopathologists of the pattern of injury manifested by increased numbers of IELs in intestinal biopsy specimens will certainly help in early diagnosis of coeliac disease, lessen diagnostic confusion and influence the modern practice of gastrointestinal tract medicine. This review discusses some of the recent developments in clinical pathology pertaining to increased IELs in small bowel mucosal biopsies.
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Affiliation(s)
- Fuju Chang
- Department of Histopathology, St Thomas' Hospital, Guy's & St Thomas' NHS Foundation Trust, London, UK.
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66
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Revaz V, Nardelli-Haefliger D. The importance of mucosal immunity in defense against epithelial cancers. Curr Opin Immunol 2005; 17:175-9. [PMID: 15766678 DOI: 10.1016/j.coi.2005.01.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Many cancers arise in epithelial mucosa. These mucosal surfaces are characterized by the induction of divergent immune responses, as they are both the main portal of entry for pathogens and a large niche of commensal bacteria and tolerized antigens. In addition, mucosa located in different anatomical sites harbor distinct typical features. Exploiting the different requirements for inducing an effective immune response at mucosal sites might help to define new immunotherapeutic approaches against epithelial cancers, at least in the case of differentiated tumors that have retained their mucosal characteristics.
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Affiliation(s)
- Véronique Revaz
- Department of Gynecology and Institute of Microbiology, Centre Hospitalier Universitaire Vaudois, 1011 Lausanne, Switzerland
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67
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Cheroutre H, Kronenberg M. Mucosal T lymphocytes--peacekeepers and warriors. ACTA ACUST UNITED AC 2005; 27:147-65. [PMID: 15931528 DOI: 10.1007/s00281-005-0205-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2005] [Accepted: 04/18/2005] [Indexed: 12/30/2022]
Abstract
Normal immune homeostasis of the intestine requires peaceful coexistence with commensal flora, combined with host defense against pathogens. Perhaps as a result of this unique dilemma, distinct populations of regulatory and effector T lymphocytes are found in the lamina propria and epithelium of the intestine. Here we summarize the properties and functions of these unusual T cells, and describe the molecular and cellular interactions that lead to their development and function. Some mucosal T cells, sometimes called type a, are conventional activated/memory T cells that have received instructions to migrate to the intestine during priming by dendritic cells in the mesenteric lymph node and elsewhere. Others, however, particularly subsets residing permanently in the epithelium, are intestine-specific T cell subpopulations generated by an atypical differentiation pathway.
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Affiliation(s)
- Hilde Cheroutre
- The La Jolla Institute for Allergy and Immunology, San Diego, CA, USA.
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68
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Ott PA, Anderson MR, Tary-Lehmann M, Lehmann PV. CD4+CD25+ regulatory T cells control the progression from periinsulitis to destructive insulitis in murine autoimmune diabetes. Cell Immunol 2005; 235:1-11. [PMID: 16122720 DOI: 10.1016/j.cellimm.2005.05.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2005] [Revised: 05/20/2005] [Accepted: 05/27/2005] [Indexed: 10/25/2022]
Abstract
Non-obese diabetic (NOD) mice develop spontaneous T-cell responses against pancreatic beta-cells, leading to islet cell destruction and diabetes. Despite high genetic similarity, non-obese resistant (NOR) mice do not develop diabetes. We show here that spleen cells of both NOD and NOR mice respond to the islet cell antigen glutamic acid decarboxylase-65 in IFN-gamma-ELISPOT assays. Moreover, NOR-T cells induce periinsulitis in NOD SCID recipient mice. Thus, a potentially pathogenic islet cell-specific T-cell response arises in NOR and NOD mice alike; the mechanism that prevents the autoimmune progression of self-reactive T cells in NOR mice presumably acts at the level of effector function. Consistent with this hypothesis, CD4+CD25+ cell-depleted spleen cells from NOR mice mediated islet cell destruction and overt diabetes in NOD SCID mice. Therefore, islet cell-specific effector cells in NOR mice appear to be under the control of CD4+CD25+ regulatory T cells, confirming the importance of regulatory cells in the control of autoimmune diabetes.
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MESH Headings
- Adoptive Transfer
- Animals
- Diabetes Mellitus, Experimental/immunology
- Diabetes Mellitus, Experimental/pathology
- Diabetes Mellitus, Type 1/immunology
- Diabetes Mellitus, Type 1/pathology
- Disease Progression
- Female
- Glutamate Decarboxylase/immunology
- Homeodomain Proteins/genetics
- Islets of Langerhans/immunology
- Islets of Langerhans/pathology
- Isoenzymes/immunology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Inbred NOD
- Mice, Knockout
- Mice, SCID
- Peptides/immunology
- Receptors, Interleukin-2/metabolism
- Spleen/cytology
- Spleen/immunology
- T-Lymphocytes, Regulatory/immunology
- T-Lymphocytes, Regulatory/metabolism
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Affiliation(s)
- Patrick A Ott
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
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69
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Eberl G. Inducible lymphoid tissues in the adult gut: recapitulation of a fetal developmental pathway? Nat Rev Immunol 2005; 5:413-20. [PMID: 15841100 DOI: 10.1038/nri1600] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The intestinal immune system faces an extraordinary challenge from the large numbers of commensal bacteria and potential pathogens that are restrained by only a single layer of epithelial cells. Here, I discuss evidence that the intestinal immune system develops an extensive network of inducible, reversible lymphoid tissues that contributes to the vital equilibrium between the gut and the bacterial flora. I propose that this network is induced by cryptopatches, which are small clusters of dendritic cells and lymphoid cells that are identical to fetal inducers of lymph-node and Peyer's-patch development.
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Affiliation(s)
- Gérard Eberl
- Laboratory of Lymphoid Tissue Development, Institut Pasteur, 25 rue du Dr. Roux, 75724 Paris, France.
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70
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Wei B, Velazquez P, Turovskaya O, Spricher K, Aranda R, Kronenberg M, Birnbaumer L, Braun J. Mesenteric B cells centrally inhibit CD4+ T cell colitis through interaction with regulatory T cell subsets. Proc Natl Acad Sci U S A 2005; 102:2010-5. [PMID: 15684084 PMCID: PMC548553 DOI: 10.1073/pnas.0409449102] [Citation(s) in RCA: 144] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Inflammatory bowel disease reflects an aberrant mucosal CD4+ T cell response to commensal enteric bacteria. In addition to regulatory T cell subsets, recent studies have revealed a protective role of B cells in murine CD4+ T cell colitis, but the relationship of their action to T cell immunoregulation is unknown. Here we report that mesenteric lymph node (MLN) B cells protect mice from colitis induced by Galphai2-/- CD4+ T cells. Protection required the transfer of both B cells and CD8alpha+ T cells; neither cell type alone was sufficient to inhibit CD4+ T cell-mediated colitis. Similar results were also observed in colitis induced by CD4+CD45RBhi T cells. Immunoregulation was associated with localization of B cells and expansion of CD4-CD8- CD3+NK1.1+ T cells in the secondary lymphoid compartment, as well as expansion of CD4+CD8alpha+ T cells in the intestinal intraepithelial compartment. MLN B cells from Galphai2-/- mice were deficient in a phenotypic subset and failed to provide cotransfer colitis protection. These findings indicate that protective action of B cells is a selective trait of MLN B cells acquired through a Galphai2-dependent developmental process and link B cells with the formation of regulatory T cells associated with mucosal immune homeostasis.
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Affiliation(s)
- Bo Wei
- Department of Pathology and Laboratory Medicine and Molecular Biology Institute, University of California, Los Angeles, CA 90095, USA
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71
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Mehandru S, Poles MA, Tenner-Racz K, Horowitz A, Hurley A, Hogan C, Boden D, Racz P, Markowitz M. Primary HIV-1 infection is associated with preferential depletion of CD4+ T lymphocytes from effector sites in the gastrointestinal tract. ACTA ACUST UNITED AC 2004; 200:761-70. [PMID: 15365095 PMCID: PMC2211967 DOI: 10.1084/jem.20041196] [Citation(s) in RCA: 841] [Impact Index Per Article: 42.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Given its population of CCR5-expressing, immunologically activated CD4(+) T cells, the gastrointestinal (GI) mucosa is uniquely susceptible to human immunodeficiency virus (HIV)-1 infection. We undertook this study to assess whether a preferential depletion of mucosal CD4(+) T cells would be observed in HIV-1-infected subjects during the primary infection period, to examine the anatomic subcompartment from which these cells are depleted, and to examine whether suppressive highly active antiretroviral therapy could result in complete immune reconstitution in the mucosal compartment. Our results demonstrate that a significant and preferential depletion of mucosal CD4(+) T cells compared with peripheral blood CD4(+) T cells is seen during primary HIV-1 infection. CD4(+) T cell loss predominated in the effector subcompartment of the GI mucosa, in distinction to the inductive compartment, where HIV-1 RNA was present. Cross-sectional analysis of a cohort of primary HIV-1 infection subjects showed that although chronic suppression of HIV-1 permits near-complete immune recovery of the peripheral blood CD4(+) T cell population, a significantly greater CD4(+) T cell loss remains in the GI mucosa, despite up to 5 yr of fully suppressive therapy. Given the importance of the mucosal compartment in HIV-1 pathogenesis, further study to elucidate the significance of the changes observed here is critical.
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Affiliation(s)
- Saurabh Mehandru
- Aaron Diamond AIDS Research Center, The Rockefeller University, 455 First Ave., 7th Fl., New York, NY 10016, USA
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