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At least 145 records · Page 8Linked to original sources
PubMed1992

Immune dysfunction following infection with chicken anemia agent and infectious bursal disease virus. I. Kinetic alterations of avian lymphocyte subpopulations.

The potential effect of chicken anemia agent (CAA) alone or in combination with infectious bursal disease virus (IBDV) on the immune system of young chickens was determined by measuring alterations in hematocrit values, lymphoid organ-to-body weight ratios and lymphoid cell concentrations at 4, 7, 10, 14, 17, 21, 28 and 42 days post-inoculation (PI). Lymphocyte subpopulations were identified and counted by flow cytometry using cell suspensions stained with monoclonal antibodies (Mabs) for panlymphocytes (K55), cytotoxic T-cells (CTLA3), T-helper cells (CT3), Ia-expressing cells (P2M11) and macrophages (P7). Chicken anemia agent induced a substantial but transient decrease in hematocrit value, thymus-to-body weight ratio and bursa-to-body weight ratio between 7 and 21 days PI corresponding to a generalized lymphocytopenia in the thymus, bursa and spleen. However, cytotoxic T-cell, T-helper cell and Ia-expressing cell concentrations increased in the bone marrow of birds inoculated with CAA alone or in combination with IBDV during the same time period. T-helper-to-cytotoxic T-cell ratios increased in the thymus and spleen during severe lymphocytopenia, indicating a selective decrease in cytotoxic T-cells. T-helper-to-cytotoxic T-cells ratios increased in the bone marrow, indicating a selective increase in T-helper cell concentrations. The increase in Ia-expressing cells in the bone marrow may be a reflection of increased number of activated T-cells which express Ia antigen. Infectious bursal disease virus alone induced a persistent depression of Ia-expressing cells in the bursa and the spleen and no measurable change in the bone marrow lymphocyte subpopulations. Chickens inoculated simultaneously with CAA and IBDV experienced clinical signs observed in chickens inoculated with each virus separately with a prolonged acute phase prior to recovery or mortality.

Animals↗
PubMed1999

Immune dysfunction in trauma.

This article documents that all immunomodulation strategies for patients sustaining traumatic injury are still under intense investigation. Although we can speculate that combination strategies may be more beneficial than single-agent immunomodulation approaches, comprehensive clinical studies are required to determine efficacious immune therapy for trauma patients. The only strategy available to clinicians caring for trauma patients is immunonutrition, and this should be strongly considered as a rational approach to improve immune function and reduce septic complications in critically ill or injured patients.

Adjuvants, Immunologic↗
PubMed1992

[Chronic fatigue immune dysfunction syndrome].

Chronic fatigue syndrome (CFS) is characterized by unexplained, debilitating fatigue or easy fatigability lasting longer than six months. While a viral basis of infection is proposed to be the cause of CFS, other viral infections do not generally persist after several weeks. Immunological disorders, including abnormal functions and distributions of T lymphocytes, B lymphocytes, natural killer (NK) cells, and monocyte/macrophages, are described in CFS. NK cells are known to play an important role in host resistance against viral infection as well as in the regulation of the immune systems. Restoration of NK activity resulted in recovery from CFS. Taken together, immunological abnormalities, especially dysfunction of NK cells, may be involved in CFS.

B-Lymphocytes↗
PubMed1999

Immune dysfunction in patients with diabetes mellitus (DM).

Patients with diabetes mellitus (DM) have infections more often than those without DM. The course of the infections is also more complicated in this patient group. One of the possible causes of this increased prevalence of infections is defects in immunity. Besides some decreased cellular responses in vitro, no disturbances in adaptive immunity in diabetic patients have been described. Different disturbances (low complement factor 4, decreased cytokine response after stimulation) in humoral innate immunity have been described in diabetic patients. However, the clinical relevance of these findings is not clear. Concerning cellular innate immunity most studies show decreased functions (chemotaxis, phagocytosis, killing) of diabetic polymorphonuclear cells and diabetic monocytes/macrophages compared to cells of controls. In general, a better regulation of the DM leads to an improvement of these cellular functions. Furthermore, some microorganisms become more virulent in a high glucose environment. Another mechanism which can lead to the increased prevalence of infections in diabetic patients is an increased adherence of microorganisms to diabetic compared to nondiabetic cells. This has been described for Candida albicans. Possibly the carbohydrate composition of the receptor plays a role in this phenomenon.

Antibody Formation↗
PubMed2026

Malignant epithelial states drive immune dysfunction in ampulla of Vater carcinoma.

BACKGROUND: Ampulla of Vater (AoV) carcinoma is a rare malignancy arising at the junction of intestinal and pancreatobiliary epithelium. Its heterogeneous clinical behavior and histological diversity have hindered therapeutic advances, and the cellular basis of this heterogeneity remains unclear. We aimed to construct a single-cell transcriptomic atlas of AoV carcinoma, with a focus on identifying epithelial subtypes and their interactions with the tumor microenvironment (TME). METHODS: We performed single-cell RNA sequencing on eight primary AoV tumors and four matched normal tissues. Comprehensive clustering and transcriptomic analyses identified cell-type composition, epithelial heterogeneity, and tumor-immune interactions. Findings were validated using deconvolution of bulk RNA-seq data from 62 AoV carcinoma patients. Results Malignant epithelial cells were categorized into four distinct subtypes: Int-Wnt, PB-KRAS, Int-Hypoxia, and Cycling stage. PB-KRAS cells exhibited stem-like transcriptional programs and high genomic instability. Deconvolution analysis of bulk RNA-seq data from the independent AoV cohort revealed that enrichment of the PB-KRAS subtype correlated with tumor recurrence and poor survival. Our immune profiling analysis discovered a significant association between PB-KRAS subtype and GZMK+ CD8+ T cells, which are in a pre-dysfunctional state, alongside SPP1+ macrophages exhibiting immunosuppressive traits. Spatial transcriptome data further supports the immunosuppressive natures of TME around PB-KRAS subtype malignant epithelial cells in AoV carcinoma. CONCLUSIONS: Our study presents a single-cell atlas of AoV carcinoma, highlighting the molecular diversity of malignant epithelium and its association with the immune microenvironment. The PB-KRAS subtype emerges as a stem-like, immunosuppressive tumor state associated with poor prognosis, providing insights for future therapeutic targeting.

Ampulla of Vater carcinoma↗
PubMed1981

An outbreak of community-acquired Pneumocystis carinii pneumonia: initial manifestation of cellular immune dysfunction.

Eleven cases of community-acquired Pneumocystis carinii pneumonia occurred between 1979 and 1981 and prompted clinical and immunologic evaluation of the patients. Young men who were drug abusers (seven patients), homosexuals (six), or both (two) presented with pneumonia. Immunologic testing revealed that absolute lymphocyte counts, T-cell counts, and lymphocyte proliferation were depressed, and that humoral immunity was intact. Of the 11 patients, one was found to have Kaposi's sarcoma, and another had angioimmunoblastic lymphadenopathy. Eight patients died. In the remaining three, no diagnosis of an immunosuppressive disease was established, despite persistence of immune defects. These cases of pneumocystosis suggest the importance of cell-mediated immune function in the defense against P. carinii. The occurrence of this infection among drug abusers and homosexuals indicates that these groups may be at high risk for this infection.

Adult↗
PubMed1990

Immune dysfunction expressed selectively on L3T4+ T cells in the tumor-bearing state.

Spleen cells from normal C3H/He or BALB/c mice generate cytotoxic T-lymphocyte (CTL) responses to both trinitrophenyl (TNP)-modified syngeneic cells (TNP-self) and allogeneic cells. In contrast, cells from these strains of mice bearing a syngeneic tumor failed to induce anti-TNP-self-CTL responses, although portions of the same responding cells generated comparable anti-allo-CTL responses to those induced by normal responding cells. Although anti-allo-CTL responses were inducible from only Lyt-2+ T-cell subset of responding cells from normal or tumor-bearing mice, induction of TNP-CTL responses required the participation of L3T4+ T-cell subset as well as Lyt-2+ CTL precursors. In addition, the fact that the addition of concanavalin A-stimulated culture supernatant to cultures of responding cells from tumor-bearing mice resulted in the induction of appreciable anti-TNP-self CTL responses demonstrated the defect of L3T4+ T-cell function in the tumor-bearing state. Such a functional defect was ascribed neither to the loss of L3T4+ T cells nor to the generation of suppressor cells in spleen cells of tumor-bearing mice. It was found on one hand that in vitro stimulation of antigen-presenting cell (APC)-depleted normal responding population with TNP-self prepared from cells of normal or tumor-bearing mice produced comparable anti-TNP CTL responses. On the other hand, APC-depleted responding cells from tumor-bearing mice were unable to induce anti-TNP CTL responses under conditions in which APC-depleted normal responding cells induced an effective TNP-CTL response. These results indicate that selective impairment of L3T4+ T cell-mediated immunity is induced in the tumor-bearing state and that such an impairment is ascribed to the dysfunction of L3T4+ T cells themselves, but not of APC required for the activation of L3T4+ T-cell subset.

Animals↗
PubMedDate not supplied

Infections in the diabetic patient: the role of immune dysfunction and pathogen virulence factors.

It is a common belief that certain infections occur more frequently in patients with diabetes mellitus than in nondiabetics. In some infections, poor diabetic control is strongly linked. Diabetics comprise 50%-70% of all patients who undergo nontraumatic foot or leg amputations, the overwhelming majority of which are necessitated by infection and necrosis of soft tissue and/or bone. Imputed host defense abnormalities include defective immune responses (e.g., white blood cell function, granuloma formation), peripheral neuropathies, impaired distal arterial supply, and problems in "control" of the diabetic state eventuating in catabolic metabolism. Increased bacterial translocation as a source of the causative bacteria is another potential entry site. Possible virulence factors of the invading organisms include polymicrobial synergism, glycocalyx formation, and inoculum size. Attention to the principles of preventive education, vascular evaluation, diabetes management, and adequate debridement maximize healing potential.

Communicable Diseases↗
PubMed1999

Activation-induced T-cell death and immune dysfunction after implantation of left-ventricular assist device.

BACKGROUND: Cardiac transplantation is a limited option for end-stage heart failure because of the shortage of donor organs. Left-ventricular assist devices (LVADs) are currently under investigation as permanent therapy for end-stage heart failure, but long-term successful device implantation is limited because of a high rate of serious infections. To examine the relation between LVAD-related infection and host immunity, we investigated immune responses in LVAD recipients. METHODS: We compared the rate of candidal infection in 78 patients with New York Heart Association class IV heart failure who received either an LVAD (n=40) or medical management (controls, n=38). Fluorochrome-labelled monoclonal antibodies were used in analyses of T-cell phenotype. Analysis of T-cell function included intradermal responses to recall antigens and proliferative responses after stimulation by phytohaemagglutinin, monoclonal antibodies to CD3, and mixed lymphocyte culture. We measured T-cell apoptosis in vivo by annexin V binding, and confirmed the result by assessment of DNA fragmentation. Activation-induced T-cell death was measured after T-cell stimulation with antibodies to CD3. All immunological tests were done at least 1 month after LVAD implantation. Between-group comparisons were by Kaplan-Meier actuarial analysis and Student's t test. FINDINGS: By 3 months after implantation of LVAD, the risk of developing candidal infection was 28% in LVAD recipients, compared with 3% in controls (p=0.003). LVAD recipients had cutaneous anergy to recall antigens and lower (<70%) T-cell proliferative responses than controls after activation via the T-cell receptor complex (p<0.001). T cells from LVAD recipients had higher surface expression of CD95 (Fas) (p<0.001) and a higher rate of spontaneous apoptosis (p<0.001) than controls. Moreover, after stimulation with antibodies to CD3, CD4 T-cell death increased by 3.2-fold in LVAD recipients compared with only 1.2-fold in controls (p<0.05). INTERPRETATION: LVAD implantation results in an aberrant state of T-cell activation, heightened susceptibility of CD4 T cells to activation-induced cell death, progressive defects in cellular immunity, and increased risk of opportunistic infection.

Adolescent↗
PubMed1978

Use of the integrated steady state rate equation to investigate product inhibition of human red cell adenosine deaminase and its relevance to immune dysfunction.

The analysis of progress curves using the integrated rate equation was applied to the adenosine deaminase-catalyzed conversion of adenosine to inosine. Adenosine deaminase was purified from human red blood cells of phenotypes ADA 1, ADA 2, and ADA 2-1. For all three types, no measurable product inhibition by inosine was observed. These results do not confirm the hypothesis that inosine accumulation in purine nucleoside phosphorylase deficiency causes adenosine deaminase inhibition, resulting in a common mechanism for the immune defects related to these two enzyme deficiencies.

Adenosine Deaminase↗
PubMed1982

Epidermodysplasia verruciformis induced by a new human papillomavirus (HPV-8). Report of a case without immune dysfunction. Effect of treatment with an aromatic retinoid.

A new case of epidermodysplasia verruciformis (EV) is reported in a 35-year-old man characterized by multiple common warts, flat warts, psoriasis-form lesions, and pityriasis-versicolor-(PV) like lesions. There was no familial history, no mental retardation, and no malignant changes. Human papilloma virus type 8 was identified in PV-like lesions. Immunologic studies detected no abnormalities: Delayed skin tests, DNCB sensitization, levels of immunoglobulins, complement components, circulating immune complexes, number of circulating lymphocytes, lymphocyte membrane markers, proliferative responses to mitogens, Ts activity, and Ts subpopulations as detected by monoclonal antibodies were considered to be within normal limits. A treatment with a retinoid aromatic (RO 10-9359) improved the clinical status of the patient and did not modify the immune parameters.

Adult↗