Biomedical subjects

P F Moore

Publications and source records attributed to P F Moore.

At least 73 records · Page 4Linked to original sources

PubMed1995

Functional interleukin-2 receptors are expressed on natural killer-like leukemic cells from a dog with cutaneous lymphoma.

We identified a dog with large granular lymphocytic leukemia and cutaneous lymphoma that exhibited constitutive expression of interleukin-2 (IL-2) receptors by the leukemic peripheral blood lymphocytes. The leukemic cells phenotypically resembled natural killer (NK) cells, and their surface IL-2 receptors were functional, as determined by the capacity to bind human recombinant IL-2 with high-affinity resulting in the transduction of proliferation signals and in the development of lymphokine-activated killer cell activity. These cells produced IL-2 spontaneously, and they may have maintained their proliferative state through an IL-2-dependent autocrine growth pathway. Our results indicate that neoplastic lymphocytes of syndromes that involve circulating leukemic cells with dermotropism can originate from NK-like cells. Additionally, the data also suggest that proliferative conditions such as these may be the result of the aberrant production of IL-2. Further, this case illustrates the potential for the use of hematopoietic malignancies in the dog as a suitable animal model for immune targeting of IL-2 receptors as a novel treatment approach for similar malignancies of human beings.

Animals↗

PubMed1995

A novel canine leukointegrin, alpha d beta 2, is expressed by specific macrophage subpopulations in tissue and a minor CD8+ lymphocyte subpopulation in peripheral blood.

The beta 2 or leukointegrin family is comprised of three structurally related leukocyte surface heterodimers: LFA-1 (CD11a/CD18), Mac-1/Mo-1 (CD11b/CD18), and p150,95 (CD11c/CD18). In this work, we describe a novel canine beta 2 (CD18)-associated leukointegrin, designated alpha d. Expression of alpha d in tissues was prominent in macrophages in splenic red pulp, lymph node medullary regions, and bone marrow. In peripheral blood, alpha d expression was limited to a minor subpopulation of CD8+ T cells, which included small lymphocytes and large granular lymphocytes. A minor subpopulation of either CD8+ or CD4-CD8- splenic red pulp lymphocytes also expressed alpha d. Immunoprecipitation of alpha d from canine splenocytes revealed a heterodimer of 155 kDa and 95 kDa. Prior clearance of splenocyte extracts with an anti-CD18 mAb resulted in complete removal of alpha d. In addition, prior clearance of canine splenocyte extracts with anti-CD11a, anti-CD11b, or anti-CD11c mAb failed to clear alpha d. These immunoclearance data indicated that canine alpha d was antigenically distinct from the three known CD11 molecules, and occurred as an alpha d beta 2 heterodimer. Amino acid sequencing of canine alpha d affinity isolated from spleen further suggested that canine alpha d beta 2 probably represented a fourth member of the canine leukointegrin family via its homology to a subsequently discovered, novel human leukointegrin, alpha d beta 2, which further supported the uniqueness of the canine protein. The discovery of canine alpha d, and the demonstration of its highly restricted cell and tissue distribution, support a re-evaluation of leukointegrin-dependent inflammatory and immunologic interactions that involve cells now known to express alpha d.

Amino Acid Sequence↗

PubMed1995

Investigation of epidermotropism in canine mycosis fungoides: expression of intercellular adhesion molecule-1 (ICAM-1) and beta-2 integrins.

In human mycosis fungoides (MF), interactions between LFA-1 (CD11a/CD18) and ICAM-1 (CD54) are involved in lymphocyte adhesion to keratinocytes. The purpose of this study was to evaluate the expression of ICAM-1, beta-2 integrins and class II major histocompatibility complex molecules (MHC II) on keratinocytes and infiltrating lymphocytes in canine MF. Sections of frozen skin biopsy specimens from normal dogs (n = 3) and dogs with MF (n = 17) were evaluated by immunohistochemistry for expression of ICAM-1, beta-2 integrins, and class II MHC molecules. Our results demonstrated that in canine MF, ICAM-1 was expressed variably on epidermal and follicular keratinocytes. The extent of keratinocyte ICAM-1 expression did not correlate with the degree of lymphocyte epithelial infiltration, nor with lymphocyte LFA-1 expression. This was especially evident in cases of Pagetoid reticulosis-like disease in which prominent lymphocyte epidermotropism was not accompanied by keratinocyte ICAM-1 expression. Keratinocyte class II MHC molecule expression did not correlate with keratinocyte ICAM-1 expression. In conclusion, in canine MF, the lack of statistically significant correlations between epithelial lymphocyte infiltration and keratinocyte ICAM-1 expression, and between keratinocyte ICAM-1 and lymphocyte LFA-1 staining, suggests that the LFA-1/ICAM-1 pathway is not the major adhesion mechanism between lymphocytes and keratinocytes. It is suspected that different ligands of the LFA-1 integrin (e.g. ICAM-2) or other adhesion molecules (e.g. CD2/LFA-3, VLA-1) might be involved in the epitheliotropism phenomenon in canine MF. These hypothesis cannot be evaluated in the dog at this time owing to the lack of specific monoclonal antibodies.

Animals↗

PubMed1995

A novel leukointegrin, alpha d beta 2, binds preferentially to ICAM-3.

The leukocyte-restricted beta 2 (CD18) integrins mediate cell adhesion in a variety of events essential for normal immune function. Despite extensive research in this field, only three members of this integrin subfamily have been described: CD11a/CD18 (LFA-1), CD11b/CD18 (Mac-1), and CD11c/CD18 (p150,95). We have identified a cDNA encoding a fourth alpha chain, alpha d, that associates with CD18. The alpha d subunit is more closely related to CD11b and CD11c than to CD11a. This integrin is expressed at moderate levels on myelomonocytic cell lines and subsets of peripheral blood leukocytes, and more strongly on tissue-compartmentalized cells such as foam cells, specialized macrophages found in aortic fatty streaks that may develop into atherosclerotic lesions. The alpha d/CD18 molecule exhibits preferential recognition of ICAM-3 over ICAM-1.

Amino Acid Sequence↗

PubMed1994

Prognostic factors for treatment of malignant lymphoma in dogs.

Pretreatment characteristics of 138 dogs with malignant lymphoma were analyzed to determine prognostic factors associated with outcome (ie, complete response rate, time to relapse after complete response, survival time). Dogs were all treated for 10 weeks, using a standard induction chemotherapy protocol, and were then given asparaginase weekly. Once the disease became progressive, second-line chemotherapy was instituted. Age, sex, weight, clinical stage, performance grade, immunophenotype, and malignancy grade assigned according to the National Cancer Institute's Working Formulation were not associated with complete response rate. However, malignancy grade assigned according to the Kiel classification was found to be associated with complete response rate; dogs with high-grade malignancies had a significantly higher complete response rate than did dogs with low-grade malignancies. By means of multivariate analysis, clinical stage and immunophenotype were found to be prognostic factors for time to relapse (among dogs that had had a complete response) and survival time. In addition, malignancy grade assigned according to the Kiel classification was found to be a prognostic factor for time to relapse; whereas, malignancy grade assigned according to the Working Formulation was determined to be a prognostic factor for survival time.

Animals↗

PubMed1994

Lymphoid follicles in the gastric mucosa of dogs. Distribution and lymphocyte phenotypes.

The occurrence and distribution of lymphoid follicles within the stomachs of 36 dogs that did not have macroscopic gastric lesions are presented. The dogs ranged in age from less than 1 year to over 13 years. The number of follicles varied between the different regions of the stomach, being most numerous (15.6 follicles cm-2) and uniform in size (about 1 mm in diameter) in the fundus. The number and size of follicles in the antrum varied widely between dogs. Age-related changes in the distribution of follicles were not found following simple linear regression analysis. The phenotypes of lymphocytes in gastric lymphoid follicles of nine dogs aged from less than 1 year to 5 years were determined using monoclonal antibodies specific for canine leucocyte antigens and an indirect immunoperoxidase technique. The follicles had an organized distribution of lymphocytes subsets in that a predominantly B cell area contained some CD4+ cells and very few CD8+ cells and was adjacent to an area containing mostly T cells. Computer-assisted morphometric analysis was used to quantify the overall presence of the various lymphocyte subpopulations. Follicles in the fundus and body regions possessed similar percentages of lymphocytes averaging 42%, 22% and 3% of the area occupied by B cells, CD4+ and CD8+ cells, respectively. It is concluded that lymphoid follicles are a normal constituent of the canine gastric mucosa and possess a lymphocyte composition similar to that reported by others for solitary intestinal follicles.

Animals↗

PubMed1994

An experimental study of primary feline immunodeficiency virus infection in cats and a historical comparison to acute simian and human immunodeficiency virus diseases.

Sixteen adolescent specific pathogen free cats were inoculated with the Petaluma strain of feline immunodeficiency virus (FIV) and two cats were then necropsied at each of 5, 10, 21, 28, 42, 56, 70, and 84 day time points following infection. Lymphadenopathy gradually increased starting at Day 10 and persisted for the duration. Gross clinical signs of fever, mild to severe malaise, anorexia, diarrhea, dehydration, and generalized soreness appeared around Day 42, peaked at Day 56, and disappeared by Days 70-84 post-infection. Leukopenia, associated initially with a mild lymphopenia and later by both a mild lymphopenia and a severe neutropenia, appeared 14-28 days following infection, troughed at Day 56, and persisted thereafter. The CD4+:CD8+ T cell ratio started to decrease around Day 28, reaching a nadir at Days 56-70. This decrease was due to a decline in the absolute numbers and percentage of CD4+ T cells and an increase in the percentage of CD8+ T cells. Significant histopathologic lesions included myeloid hyperplasia between Days 56-70 post-infection; thymitis with cortical involution and follicular hyperplasia starting at Day 42; lymphoid hyperplasia of peripheral and mesenteric nodes, spleen and tonsils beginning around Day 42; typhlitis most evident from Day 56 onward, and an interstitial nephritis and pneumonitis that was most intense after Day 42. Virus was isolated from peripheral blood mononuclear cells (PBMC) beginning 2 weeks post-infection, and plasma viremia appeared 1 week later. Plasma and PBMC-associated viremia peaked at 42-56 days following infection and decreased abruptly thereafter. Proviral DNA was detectable as early as 5 days after infection in blood leukocytes and after 10 days in other organs. The central nervous system, lungs, thymus, tonsils and mesenteric lymph nodes were the earliest sites of virus localization. Antibodies to the FIV capsid protein appeared 14 days following infection and reached peak levels by Days 42-56. Abnormalities occurring during the primary stage of FIV infection were consistent with those described for acute simian and human immunodeficiency virus-induced disease.

Acquired Immunodeficiency Syndrome↗

PubMed1994

T-cell receptor gene rearrangement in canine mycosis fungoides: further support for a canine model of cutaneous T-cell lymphoma.

Canine cutaneous T-cell lymphoma (CTCL) is a morphologic and immunophenotypic simulant of human mycosis fungoides (MF) characterized by an infiltrate of atypical, hyperconvoluted, epidermotropic T cells. To further support our hypothesis that canine MF is a useful model for the study of human CTCL, we have used Southern blotting to search for clonal T-cell proliferations in canine MF. Cellular DNA was extracted from normal dog buffy coat cells (n = 8), lesional canine MF skin (n = 8), canine MF buffy coat cells (n = 7), normal dog skin (n = 3), and normal human buffy coat cells (n = 5), digested with a panel of restriction enzymes and Southern blotted onto nylon membranes. All cases of canine MF were also immunophenotyped with anti-canine monoclonal antibodies to CD4, CD8, CD18, CD45RA, canine class II, T-cell activation antigens, and pan-B-cell antigens. Normal dogs gave reproducible digestion patterns in blood and skin, which differed from the human germline patterns when probed with a human T-cell receptor (TCR), beta chain constant region (C beta) cDNA. Common germline bands between the species included the 3.5-kb Eco RI, 3.4-kb Bam HI, 5.4-kb Sac I. These results confirmed that the TCR-beta gene is evolutionarily conserved between dog and man. Immunostaining revealed that 3/7 cases were CD4+ canine CTCL and 4/7 were CD8+ canine CTCL. Rearranged bands, deletion of germline bands, as well as minor alterations in electrophoretic mobility were observed in lesional DNA from seven of eight cases of canine MF, with at least two restriction digests in each case. Dog rearrangements were best detected with Bgl II, Eco RI, Eco RV, and Sac I, whereas deletions were detected with Bgl II, Sac I, Eco RV, and Bam HI. These studies demonstrate the presence of clonal TCR rearrangement in canine MF, further supporting the similarity of this tumor to human MF and its role as an animal model of CTCL.

Animals↗

PubMed1994

Characterization of a novel bovine leukocyte protein involved in cell-cell adhesion.

Preliminary characterization of an apparently novel bovine leukocyte adhesion protein is described. Two IgG1 monoclonal antibodies, UC-C1 and UC-H5, raised against established cultures of IL-2-dependent bovine peripheral blood lymphocytes (PBL) were found to react with an antigen expressed by the majority of bovine peripheral blood leukocytes. Immunoprecipitation and polyacrylamide gel electrophoresis of the antigen produced a distinct protein band of molecular weight 160,000, and additional diffuse protein bands of approximate molecular weight 180,000, 175,000, and 150,000. Two-color flow cytometric analyses showed that the antigen was expressed at low density on a small proportion of circulating B lymphocytes, but was highly expressed on all circulating T lymphocytes. The majority of monocytes and all granulocytes expressed the antigen at a density lower than that of T lymphocytes. Peripheral blood lymphocytes stimulated with concanavalin A had an approximately 3-fold increased expression of the antigen, which was apparent within 18 h and remained stable in long-term cultures. Expression of the antigen in thymus, analyzed by the immunoperoxidase technique, was predominantly restricted to thymocytes in the immediate subcapsular cortex and medulla; expression in lymph nodes and spleen was predominantly confined to lymphocytes in T-cell areas. Flow-cytometric analysis demonstrated that thymocytes and the majority of peripheral and mesenteric lymph node-derived T cells had relatively low surface density of antigen compared to circulating T cells. Binding of UC-C1 or UC-H5 to the antigen on lymphocytes induced homotypic aggregation. UC-C1 completely blocked binding of FITC-conjugated UC-H5 to blood mononuclear cells, suggesting that the antibodies recognize the same epitope or proximal epitopes.

Animals↗

PubMed1994

Primary stage of feline immunodeficiency virus infection: viral dissemination and cellular targets.

The objective of this study was to identify cellular and organ targets of acute feline immunodeficiency virus (FIV) infection in vivo. Tissues of FIV-infected cats were studied at eight time points during the first 3 months after experimental infection. FIV nucleic acids were first detected by in situ hybridization 21 days after infection, approximately 1.5 weeks after lymph node enlargement was first observed and 3 weeks before the primary acute flu-like illness. The majority of FIV-infected cells were present in lymphoid organs, though low numbers of infected cells were noted in nonlymphoid organs as well. Germinal centers harbored many of the FIV-infected cells within lymphoid tissues. The thymic cortex was also a major site of early infection. Combined in situ hybridization and immunohistochemistry revealed that T lymphocytes were the primary target of early FIV infection in tissues of cats before the onset of clinical signs of acute illness. An unidentified population of mononuclear cells and a few macrophages were also infected. During the ensuing acute flu-like illness, the proportion of FIV-infected macrophages in tissues increased dramatically. This early shift in the predominant cellular localization of FIV from T lymphocytes to macrophages may be important for establishing viral persistence.

Animals↗

PubMed1994

Characterization of monoclonal antibodies specific for equine homologues of CD3 and CD5.

Two monoclonal antibodies (mAb), UC F6G-3 and UC F13C-5, were characterized as being specific for the apparent equine homologues of CD3 and CD5, respectively. Both antibodies exhibited characteristics of pan-T-lymphocyte markers based upon immunohistology and two-colour flow cytometry. UC F6G-3 precipitated a complex of proteins (up to seven) with molecular weights ranging from 18,000 to 42,000, similar to the human and murine CD3 complex. Upon further dissociation of the precipitated complex, two proteins were identified with molecular weights of 22,000 and 27,000. Immobilized UC F6G-3 was effective at inducing interleukin-2 receptor (IL-2R) expression on T lymphocytes, a feature consistent with antibodies specific for the epsilon chain of human and murine CD3. Three populations of cells in the thymus were distinguishable by UC F6G-3 target antigen density, suggesting increasing stages of T-cell maturation. UC F13C-5 precipitated a 67,000 MW protein, consistent with reported values for CD5 in multiple species. While this antibody exhibited characteristics of a pan-T-cell marker, low numbers of B lymphocytes also expressed the target antigen. Phorbol esters induced variable increases in target antigen density on B lymphocytes. These two antibodies, taken together with the few equine CD markers currently available, represent a substantial resource for further defining the equine immune system in health and disease.

Animals↗

PubMed1994

Canine cutaneous epitheliotropic lymphoma (mycosis fungoides) is a proliferative disorder of CD8+ T cells.

Canine epitheliotropic lymphoma (mycosis fungoides [MF]) is a spontaneous neoplasm of skin and mucous membranes that occurs in old dogs (mean age 11 years) and has no breed predilection. The lesions evolve from a patch-plaque stage with prominent epitheliotropism into a tumor stage in which distant metastasis is observed. Unlike human MF, epitheliotropism of the lymphoid infiltrate is still prominent in tumor stage lesions. Tropism of the lymphoid infiltrate for adnexal structures, especially hair follicles and apocrine sweat glands, was marked in all clinical stages of canine MF. Twenty-three cases of MF were subjected to extensive immunophenotypic analysis in which reagents specific for canine leukocyte antigens and fresh frozen tissue sections of the canine lesions were used. Canine MF proved to be a T cell lymphoma in which the epitheliotropic lymphocytes consistently expressed CD3 (22 cases) and CD8 (19 cases); CD3+CD4-CD8- lymphocytes predominated in the remaining 4 cases. In this regard, canine MF clearly differed from human MF in which a CD4 immunophenotype predominates in the T cell infiltrate. Lack of expression of CD45RA by epitheliotropic T cells and intense expression of a beta 1 integrin (VLA-4-like) suggested that T cells in canine MF belonged to the memory subpopulation, as has been suggested for T cells in human MF. Pan-T cell antigen loss or discordant expression also proved useful as phenotypic indicators of neoplasia in canine MF. Loss of CD5 was observed in epitheliotropic T cells in 63% of cases. Discordance of neoplastic T cell Thy-1 expression was frequently observed between epithelial and dermal or submucosal compartments. We conclude that canine MF still represents a useful spontaneous animal disease model of human cutaneous T cell lymphoma, despite the immunophenotypic differences, which may reflect operational differences between human and canine skin-associated lymphoid tissue.

Animals↗

PubMed1994

Histologic classification and immunophenotyping of canine non-Hodgkin's lymphomas: unexpected high frequency of T cell lymphomas with B cell morphology.

Using three different classification schemes (Rappaport, the Working Formulation, and the Kiel classification), 116 canine malignant lymphomas were classified histologically. The number of lymphomas with a completely follicular growth pattern was low (14.9%). The majority of the lymphomas (50.8%) had a diffuse type of architecture, while 34.3% were diffuse with some nodularity. In the Rappaport scheme, 69.3% of the canine lymphomas were classified as histiocytic lymphomas, but these consisted of a group of tumors with different morphologic and immunologic cell types. The Working Formulation and the Kiel classification could be applied to differentiate the canine lymphomas cytomorphologically. In both the Working Formulation and the Kiel classification, only a minority of lymphomas (16.4 and 12.0%, respectively) were low-grade malignant lymphomas. Large cell or centroblastic lymphomas were the most frequently encountered in the Working Formulation or the Kiel classification, respectively. Immunophenotyping of 95 lymphomas was performed with the aid of a panel of monoclonal and polyclonal antibodies. The majority of the lymphomas were of B cell origin (58.9%) while three were classified as non-B/non-T cell lymphomas. Contrary to the distribution pattern of human non-Hodgkin's lymphoma (NHL) in western countries, there was a high percentage of T cell lymphomas (37.9%) in the canine. However, the phenotype could not be predicted by the morphologic characteristics alone.

Animals↗

PubMed1993

Differential expression of bovine MHC class II antigens identified by monoclonal antibodies.

Four monoclonal antibodies (mAbs), UC-A4, UC-D3, UC-H9, and IL-A21, specific for bovine major histocompatibility complex class II proteins are described. Sequential immunoprecipitation experiments using biotin-labeled peripheral blood mononuclear cells suggested, but did not conclusively establish, that each of these antibodies recognized a different epitope. The epitope identified by IL-A21 appeared to be common to all of the class II proteins precipitated by the four mAbs, and UC-D3 and UC-H9 each appeared to react with distinct epitopes on separate subsets of these class II proteins. Monoclonal antibody UC-A4 appeared to identify an epitope on a subset of the class II molecules identified by UC-H9. Differences found in the expression by lymphoid cells of class II proteins identified by the four mAbs were indicative of each mAb recognizing a different epitope. UC-H9 and IL-A21 class II proteins were detected on all surface immunoglobulin (S'Ig) positive cells in peripheral blood, but UC-A4 and UC-D3 class II proteins were not. Expression of UC-A4 class II proteins, detected at low density on a strikingly reduced number of S'Ig+ cells from the blood of some bovine leukosis virus-infected cattle, could be increased by culturing these B cells with lipopolysaccharide. All peripheral blood monocytes expressed UC-H9 and IL-A21 class II proteins, but only a proportion of monocytes expressed detectable UC-A4 and UC-D3 class II proteins. Almost all mitogen-stimulated BoCD4+ and BoCD8+ T cells expressed UC-H9 and IL-A21 class II proteins, whereas fewer stimulated T cells of both subsets expressed UC-A4 and UC-D3 class II proteins. All gamma/delta receptor (gamma/delta R) T cells expressed UC-D3, UC-H9, and IL-A21 class II proteins, but no cells (of gamma/delta R+ or CD4+/CD2+ phenotype) from gamma/delta R+ T cell-enriched cultures expressed UC-A4 class II proteins.

Animals↗

PubMed1993

Ampiroxicam, an anti-inflammatory agent which is a prodrug of piroxicam.

Ampiroxicam is a nonacidic ether carbonate prodrug of piroxicam. Our results demonstrate that, in contrast to piroxicam, ampiroxicam does not possess detectable prostaglandin synthesis inhibitory activity in vitro. Ampiroxicam, however, has similar in vivo potency to piroxicam in suppressing paw swelling in rat adjuvant arthritis. In an acute model of paw inflammation in rats, ampiroxicam is less potent than piroxicam itself: the ED50's of ampiroxicam are 9- and 3.5-fold higher than those of piroxicam following a single or multiple (5) daily oral doses, respectively. Using the phenylbenzoquinone stretching test as a method of evaluating acute analgetic activity, the ED50 for ampiroxicam is about 3-fold higher than that of piroxicam. These tests of activity share the property of being partially prostaglandin-dependent. Ampiroxicam itself is not observed in plasma after oral dosing to man, nor in the rat, dog, and monkey as reported here. Bioavailability studies show that conversion to piroxicam is about 100%, 90%, 70%, and 50% in these four species, respectively. These results indicate that ampiroxicam's anti-inflammatory activity is produced in vivo by conversion to piroxicam and support its credentials as an efficacious prodrug of piroxicam.

Animals↗

PubMed1992

Dermal dendrocytes and T-cells in canine mycosis fungoides. Support for an animal model of human cutaneous T-cell lymphoma.

BACKGROUND: An extensive upper dermal network of human Thy-1+/Factor XIIa+ dermal dendrocytes (DD) exists in human mycosis fungoides (MF). METHODS: Immunophenotyping and morphologic studies on serial frozen and paraffin sections from 15 cases of canine MF were performed to see if a similar network exists in this disease, as has been proposed as an animal model of human MF. Primary antibodies were anti-human Factor XIIIa, Factor XIIIs, anti-canine Thy-1, CD4, CD8, CD18, CD45RA, Class II, MAC387, KP-1, EBM-11, and several other pan-T, pan-B, and pan monocyte markers. RESULTS: Thy-1+/Factor XIIIa+DD were seen in all cases and confirmed on identical cells by double immunofluorescence. These were seen throughout the upper dermis, similar to DD in human MF. Canine DD expressed the macrophage marker 2A2+, and were Class II+, CD4+, CD8-, CD18+, EBM11-, Factor XIII-, MAC387-, and KP-1. Epidermal and dermal lymphocytes in canine MF were Thy-1-, CD4+, CD8-, CD18+, CD45RA-, EBM11-, MAC387-, Factor XIIIa-, Factor XIIIs- in some cases, whereas others had a predominance of CD8+ lymphocytes. CONCLUSIONS: Thus, canine MF is immunophenotypically similar to human MF. Additional support for this disease as a model of human MF is demonstrated by the rich network of Thy-1+/Factor XIIIa+ DD in the upper dermis of canine MF similar to human MF.

Animals↗

PubMed1992

Persistent upregulation of MHC class II antigen expression on T-lymphocytes from cats experimentally infected with feline immunodeficiency virus.

A significant elevation in the percentage of CD4+ and CD8+ T-lymphocytes expressing major histocompatibility complex (MHC) Class II antigens was observed in the blood of cats shortly after they were experimentally infected with feline immunodeficiency virus (FIV). In addition to an increase in the relative proportion of T-lymphocytes expressing Class II antigens, there was an increase in the density of Class II antigens on the cell surface. These elevations were still evident at the completion of the 5 month study. A second group of cats that had been infected with FIV for almost 5 years, and with either normal or abnormally low levels of CD4+ T-lymphocytes, had similar elevations in MHC II expression, suggesting that such abnormalities are lifelong. Cats with chronic (2 year) feline leukemia virus (FeLV) infection or dual FIV/FeLV infections also showed similar alterations in MHC II expression on CD4+ and CD8+ T-lymphocytes, suggesting that these alterations were not FIV specific. Feline T-lymphocytes expressed more MHC II antigen and interleukin-2 (IL-2) receptor following stimulation in vitro with conconavalin A and IL-2, demonstrating that feline T-lymphocytes respond to activation signals in a manner similar to T-lymphocytes of other species. However, changes in MHC II expression on T-cells of FIV infected cats were not explainable by viral induced T-cell activation alone, because FIV infected cats with elevated MHC II expression did not have coincident elevations in IL-2 receptor expression.

Animals↗

PubMed1992

Canine leukocyte cell adhesion molecules (LeuCAMs): characterization of the CD11/CD18 family.

The canine LeuCAM (CD11/CD18) family is characterized using a panel of newly developed anti-canine LeuCAM monoclonal antibodies (mAb) as well as a cross-reactive anti-human CD11b mAb. The new anti-canine LeuCAM mAb were developed by immunizing mice with purified canine CD11/CD18 antigen derived from an anti-canine CD18 affinity column. Six mAb with reactivity to the canine LeuCAM family were cloned and characterized. These 6 included a new anti-canine CD18 mAb, 2 anti-canine CD11a mAb, 2 anti-canine CD11c mAb, and a mAb which recognizes a novel canine CD11/CD18-related macrophage antigen, designated LeuCAMmac, which is described in a separate report. The cell and tissue distribution of canine LeuCAMs was found to be similar to that reported in other species with a few notable exceptions. One prominent exception was the finding that canine CD11c, in contrast to human CD11c, was much more widely distributed on dendritic cells than it was on tissue macrophages. The molecular organization of the canine LeuCAM family was also found to be similar to that reported in other species, with the possible exception of the canine CD11b alpha chain, which may exist as several different species. It is anticipated that these anti-canine LeuCAM mAb will prove useful in immunophenotypic studies of canine hemolymphatic system neoplasia.

Animals↗