scholarly journals Intracellular Staphylococcus aureusEscapes the Endosome and Induces Apoptosis in Epithelial Cells

1998 ◽  
Vol 66 (1) ◽  
pp. 336-342 ◽  
Author(s):  
Kenneth W. Bayles ◽  
Carla A. Wesson ◽  
Linda E. Liou ◽  
Lawrence K. Fox ◽  
Gregory A. Bohach ◽  
...  

ABSTRACT We examined the invasion of an established bovine mammary epithelial cell line (MAC-T) by a Staphylococcus aureusmastitis isolate to study the potential role of intracellular survival in the persistence of staphylococcal infections. S. aureuscells displayed dose-dependent invasion of MAC-T cells and intracellular survival. An electron microscopic examination of infected cells indicated that the bacteria induced internalization via a mechanism involving membrane pseudopod formation and then escaped into the cytoplasm following lysis of the endosomal membrane. Two hours after the internalization of S. aureus, MAC-T cells exhibited detachment from the matrix, rounding, a mottled cell membrane, and vacuolization of the cytoplasm, all of which are indicative of cells undergoing programmed cell death (apoptosis). By 18 h, the majority of the MAC-T cell population exhibited an apoptotic morphology. Other evidence for apoptosis was the generation of MAC-T cell DNA fragments differing in size by increments of approximately 180 bp and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling of the fragmented nuclear DNA of the infected host cells. These results demonstrate that after internalizationS. aureus escapes the endosome and induces apoptosis in nonprofessional phagocytes.

Author(s):  
R.E. Nordquist ◽  
R.M. Wasik ◽  
P.J. Riggs ◽  
P.L. Munson ◽  
F.B. Schafer

An infiltrating ductal cell carcinoma was removed from the breast of a postmenopausal Caucasian female. The excised tissue was divided into three parts; one part for electron microscopy, one part for tissue culture and the remainder frozen for immunological studies.The tissue for culture was minced finely with sterile razor blades and cultured in Falcon flasks containing Eagel's MEM supplemented with 10% heat denatured fetal calf serum. The tissue for electron microscopy was fixed in 6.25% glutaraldehyde in 0.1 M PO4 buffer plus 5% sucrose and postfixed in 1% OsO4 in the same buffer. The fixed tissue was dehydrated in graded ethanol and embedded in Spurr.The tissue which was cultured began to grow out after approximately six weeks and became a continuous epithelial cell line which was designated BOT-2 (Breast Original Tumor). Electron microscopic examination revealed that these cells had epithelial characteristics, i.e. the presence of tonofilaments and well formed desmosomes.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xiaohui Wang ◽  
Xiang Lin ◽  
Zihan Zheng ◽  
Bingtai Lu ◽  
Jun Wang ◽  
...  

AbstractInnate immunity is important for host defense by eliciting rapid anti-viral responses and bridging adaptive immunity. Here, we show that endogenous lipids released from virus-infected host cells activate lung γδ T cells to produce interleukin 17 A (IL-17A) for early protection against H1N1 influenza infection. During infection, the lung γδ T cell pool is constantly supplemented by thymic output, with recent emigrants infiltrating into the lung parenchyma and airway to acquire tissue-resident feature. Single-cell studies identify IL-17A-producing γδ T (Tγδ17) cells with a phenotype of TCRγδhiCD3hiAQP3hiCXCR6hi in both infected mice and patients with pneumonia. Mechanistically, host cell-released lipids during viral infection are presented by lung infiltrating CD1d+ B-1a cells to activate IL-17A production in γδ T cells via γδTCR-mediated IRF4-dependent transcription. Reduced IL-17A production in γδ T cells is detected in mice either lacking B-1a cells or with ablated CD1d in B cells. Our findings identify a local host-immune crosstalk and define important cellular and molecular mediators for early innate defense against lung viral infection.


Blood ◽  
1990 ◽  
Vol 75 (6) ◽  
pp. 1346-1355
Author(s):  
K Offit ◽  
JP Burns ◽  
I Cunningham ◽  
SC Jhanwar ◽  
P Black ◽  
...  

Serial cytogenetic studies were performed on 64 patients with chronic myelogenous leukemia (CML) after T cell-depleted allogeneic bone marrow transplantation (BMT). Forty patients with CML in chronic phase (CP) received cytoreduction followed by BMT with HLA-matched T cell-depleted allogeneic marrow. The remaining 24 patients were transplanted in second chronic, accelerated, or blastic phase, or received T cell- depleted grafts with a dose of T cells added back. The Y chromosome and autosomal heteromorphisms were used to distinguish between donor and host cells. Mixed hematopoietic chimerism (presence of donor and host cells) was identified in 90% of patients in first CP. The Philadelphia (Ph) chromosome reappeared in 16 of the 40 first CP CML patients. As expected, patients who had detectable Ph chromosome positive cells at any time during the posttransplant period had a high likelihood of subsequent clinical relapse. Transient disappearance of the Ph positive clone was rarely observed, and was followed by reappearance of the Ph chromosome or clinical relapse. A subset of engrafted patients with greater than 25% host cells within 3 months post-BMT had a significantly shorter survival time free of cytogenetic or clinical relapse compared with other patients. In patients who had received donor T cells added to the T cell-depleted graft, there was a higher proportion of complete chimerism. Clonal progression of Ph positive as well as negative cells was observed and may be the result of radiation induced breakage. Serial cytogenetic studies of patients post-BMT can provide useful information regarding the biologic and clinical behavior of CML.


1993 ◽  
Vol 39 (11) ◽  
pp. 1014-1021 ◽  
Author(s):  
L. Mihailova ◽  
N. Markova ◽  
T. Radoucheva ◽  
D. Veljanov ◽  
S. Radoevska

Listeria monocytogenes 4b and its forms without cell walls (L forms of a protoplastic type) were used to study in vivo interactions with host cells. Samples of peritoneal lavage fluid were obtained from rats intraperitoneally inoculated at intervals between 1 and 15 days after challenge, for scanning electron microscopic, bacteriological, biochemical, and cytometrical investigations. Scanning electron microscopic examination revealed continuous adhesion of L forms on the macrophage surface up to 15 days after inoculation. The persistence of the L forms within the peritoneal cavity was also shown bacteriologically at all sample times, while the parental bacterial forms were isolated from the peritoneal cavity up to 7 days after challenge. The total count of peritoneal exudative cells determined by automated flow peroxidase cytometry peaked on the 15th day in animals infected with parental forms, while in animals infected with L forms the peak was lower and the macrophage population was predominant. The glycolytic and acid phosphatase activity of peritoneal exudative cells was two times higher in rats infected with L forms as compared with rats infected with the L. monocytogenes parental forms on the 3rd day after challenge. An understanding of the nature of the interactions between L forms of L. monocytogenes and peritoneal exudative cells found in vivo could be used to establish the influence of L forms on host cellular defense mechanisms.Key words: Listeria monocytogenes, L forms, peritoneal exudative cells, electron microscopy.


1993 ◽  
Vol 177 (1) ◽  
pp. 207-212 ◽  
Author(s):  
E Ennis ◽  
R R Isberg ◽  
Y Shimizu

Bacteria and viruses often use the normal biological properties of host adhesion molecules to infect relevant host cells. The outer membrane bacterial protein invasin mediates the attachment of Yersinia pseudotuberculosis to human cells. In vitro studies have shown that four members of the very late antigen (VLA) integrin family of adhesion molecules, VLA-3, VLA-4, VLA-5, and VLA-6, can bind to invasin. Since CD4+ T cells express and use these integrins, we have investigated the interaction of CD4+ T cells with purified invasin. Although VLA integrin-mediated adhesion of T cells to other ligands such as fibronectin does not occur at high levels unless the T cells are activated, resting T cells bind strongly to purified invasin. The binding of resting T cells to invasin requires metabolic activity and an intact cytoskeleton. Although CD4+ T cells express VLA-3, VLA-4, VLA-5, and VLA-6, monoclonal antibody (mAb) blocking studies implicate only VLA-4 as a T cell invasin receptor. Like other integrin ligands, invasin can facilitate T cell proliferative responses induced by a CD3-specific mAb. These results suggest that the nature of the integrin ligand is a critical additional factor that regulates T cell integrin activity, and that direct interactions of T cells with bacterial pathogens such as Yersinia may be relevant to host immune responses to bacterial infection.


Cells ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 829 ◽  
Author(s):  
Klaus-Peter Künkele ◽  
Daniela Wesch ◽  
Hans-Heinrich Oberg ◽  
Martin Aichinger ◽  
Verena Supper ◽  
...  

Cancer therapies based on in vivo stimulation, or on adoptive T cell transfer of Vγ9Vδ2 T cells, have been tested in the past decades but have failed to provide consistent clinical efficacy. New, promising concepts such as γδ Chimeric Antigen Receptor (CAR) -T cells and γδ T-cell engagers are currently under preclinical evaluation. Since the impact of factors, such as the relatively low abundance of γδ T cells within tumor tissue is still under investigation, it remains to be shown whether these effector T cells can provide significant efficacy against solid tumors. Here, we highlight key learnings from the natural role of Vγ9Vδ2 T cells in the elimination of host cells bearing intracellular bacterial agents and we translate these into the setting of tumor therapy. We discuss the availability and relevance of preclinical models as well as currently available tools and knowledge from a drug development perspective. Finally, we compare advantages and disadvantages of existing therapeutic concepts and propose a role for Vγ9Vδ2 T cells in immune-oncology next to Cluster of Differentiation (CD) 3 activating therapies.


2019 ◽  
Vol 216 (11) ◽  
pp. 2619-2634 ◽  
Author(s):  
Ping-Hsien Lee ◽  
Tori N. Yamamoto ◽  
Devikala Gurusamy ◽  
Madhusudhanan Sukumar ◽  
Zhiya Yu ◽  
...  

Host conditioning has emerged as an important component of effective adoptive cell transfer–based immunotherapy for cancer. High levels of IL-1β are induced by host conditioning, but its impact on the antitumor function of T cells remains unclear. We found that the administration of IL-1β increased the population size and functionality of adoptively transferred T cells within the tumor. Most importantly, IL-1β enhanced the ability of tumor-specific T cells to trigger the regression of large, established B16 melanoma tumors in mice. Mechanistically, we showed that the increase in T cell numbers was associated with superior tissue homing and survival abilities and was largely mediated by IL-1β–stimulated host cells. In addition, IL-1β enhanced T cell functionality indirectly via its actions on radio-resistant host cells in an IL-2– and IL-15–dependent manner. Our findings not only underscore the potential of provoking inflammation to enhance antitumor immunity but also uncover novel host regulations of T cell responses.


Blood ◽  
1990 ◽  
Vol 75 (6) ◽  
pp. 1346-1355 ◽  
Author(s):  
K Offit ◽  
JP Burns ◽  
I Cunningham ◽  
SC Jhanwar ◽  
P Black ◽  
...  

Abstract Serial cytogenetic studies were performed on 64 patients with chronic myelogenous leukemia (CML) after T cell-depleted allogeneic bone marrow transplantation (BMT). Forty patients with CML in chronic phase (CP) received cytoreduction followed by BMT with HLA-matched T cell-depleted allogeneic marrow. The remaining 24 patients were transplanted in second chronic, accelerated, or blastic phase, or received T cell- depleted grafts with a dose of T cells added back. The Y chromosome and autosomal heteromorphisms were used to distinguish between donor and host cells. Mixed hematopoietic chimerism (presence of donor and host cells) was identified in 90% of patients in first CP. The Philadelphia (Ph) chromosome reappeared in 16 of the 40 first CP CML patients. As expected, patients who had detectable Ph chromosome positive cells at any time during the posttransplant period had a high likelihood of subsequent clinical relapse. Transient disappearance of the Ph positive clone was rarely observed, and was followed by reappearance of the Ph chromosome or clinical relapse. A subset of engrafted patients with greater than 25% host cells within 3 months post-BMT had a significantly shorter survival time free of cytogenetic or clinical relapse compared with other patients. In patients who had received donor T cells added to the T cell-depleted graft, there was a higher proportion of complete chimerism. Clonal progression of Ph positive as well as negative cells was observed and may be the result of radiation induced breakage. Serial cytogenetic studies of patients post-BMT can provide useful information regarding the biologic and clinical behavior of CML.


Blood ◽  
1979 ◽  
Vol 53 (6) ◽  
pp. 1066-1075 ◽  
Author(s):  
EL Reinherz ◽  
LM Nadler ◽  
DS Rosenthal ◽  
WC Moloney ◽  
SF Schlossman

Abstract Circulating peripheral blood tumor cells in four cases of chronic lymphoproliferative disease were immunologically characterized. By the use of T-cell-specific heteroantisera and indirect immunofluorescence, all were shown to involve proliferation of malignant T cells. Three cases demonstrated morphologic and clinical features consistent with chronic lymphocytic leukemia (CLL), and one case presented as a lymphosarcoma cell leukemia. Antisera specific for normal human T-cell subsets defined the malignant T cells in each case as arising from the TH2--subset. This subset normally constitutes approximately 80% of human peripheral blood T cells. Terminal deoxynucleotidyl transferase (TdT) was not detected in any of the T-cell CLL cases, thus supporting the notion that T-cell CLL represents a malignancy of a mature phenotype. The one patient with lymphosarcoma whose tumor cells were TdT-positive subsequently developed T-cell acute lymphoblastic leukemia (ALL). Moreover, la-like antigen (p23,30) was detected on two of these tumor cell populations. In addition, it was shown that not all tumor cells were E-rosette-positive, since only cells from 3 of 4 patients were capable of forming spontaneous rosettes. These findings demonstrate that heteroantisera can provide an additional important tool for dissecting the heterogeneity of T-cell leukemias and for relating them to more differentiated normal T cells.


2014 ◽  
Vol 82 (10) ◽  
pp. 4092-4103 ◽  
Author(s):  
Abinav Kumar Singh ◽  
Nagaraja R. Thirumalapura

ABSTRACTDiverse pathogens have evolved to survive and replicate in the endosomes or phagosomes of the host cells and establish persistent infection. Ehrlichiae are Gram-negative, intracellular bacteria that are transmitted by ticks. Ehrlichiae reside in the endosomes of the host phagocytic or endothelial cells and establish persistent infection in their vertebrate reservoir hosts. CD4+T cells play a critical role in protection against phagosomal infections. In the present study, we investigated the expansion, maintenance, and functional status of antigen-specific CD4+T cells during persistentEhrlichia murisinfection in wild-type and interleukin-10 (IL-10)-deficient mice. Our study indicated that early induction of IL-10 led to reduced inflammatory responses and impaired bacterial clearance during persistentEhrlichiainfection. Notably, we demonstrated that the functional production of gamma interferon (IFN-γ) by antigen-specific CD4+T cells maintained during a persistent phagosomal infection progressively deteriorates. The functional loss of IFN-γ production by antigen-specific CD4+T cells was reversed in the absence of IL-10. Furthermore, we demonstrated that transient blockade of IL-10 receptor during the T cell priming phase early in infection was sufficient to enhance the magnitude and the functional capacity of antigen-specific effector and memory CD4+T cells, which translated into an enhanced recall response. Our findings provide new insights into the functional status of antigen-specific CD4+T cells maintained during persistent phagosomal infection. The study supports the concept that a better understanding of the factors that influence the priming and differentiation of CD4+T cells may provide a basis to induce a protective immune response against persistent infections.


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