Characterization of peripheral blood and pulmonary leukocyte function in healthy foals

Flaminio, M. Julia B.F.; Rush, Bonnie R.; Davis, Elizabeth G.; Hennessy, K J; Shuman, Wilma; Wilkerson, Melinda J.

doi:10.1016/s0165-2427(00)00149-5

Cited by 74 publications

(65 citation statements)

References 30 publications

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“…Consistent with previous studies, the present study also found a significantly higher percentage of macrophages and significantly lower percentage of T lymphocytes, CD4 ϩ T lymphocytes, and CD8 ϩ T lymphocytes in BAL fluid of healthy foals than in healthy adult horses (6,13). Infection with R. equi in foals does not result in significant alterations in lymphocyte subpopulations in peripheral blood (14).…”

Section: Discussionsupporting

confidence: 92%

Experimental Infection of Neonatal Foals withRhodococcus equiTriggers Adult-Like Gamma Interferon Induction

Jacks

Giguère

Crawford

et al. 2007

Clin Vaccine Immunol

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Rhodococcus equi is a facultative intracellular pathogen that causes pneumonia in young foals but does not induce disease in immunocompetent adult horses. Clearance of R. equi depends mainly on gamma interferon (IFN-␥) production by T lymphocytes, whereas the predominance of interleukin 4 (IL-4) is detrimental. Young foals, like neonates of many other species, are generally deficient in the ability to produce IFN-␥. The objective of this study was to compare the cytokine profiles, as well as cell-mediated and antibody responses, of young foals to those of adult horses following intrabronchial challenge with R. equi. The lymphoproliferative responses of bronchial lymph node (BLN) cells to concanavalin A were significantly higher in foals than in adult horses. In contrast, adult horses had significantly higher lymphoproliferative responses to R. equi antigens than did foals. Infected foals had significantly lower IL-4 mRNA expression but significantly higher IFN-␥ expression and IFN-␥/IL-4 ratio in R. equi-stimulated BLN lymphocytes than did infected adults. Infection with R. equi in foals resulted in a significant increase in the percentage of T lymphocytes and CD4 ؉ T lymphocytes in bronchoalveolar lavage fluid in association with a significant decrease in the percentage of these cell populations in BLNs. Infection of foals also resulted in a marked increase in serum immunoglobulin Ga (IgGa) and IgGb levels, resulting in concentrations in serum that were significantly higher than those of adult horses. This study demonstrates that the immune response to R. equi in foals is not biased toward IL-4 and is characterized by the predominant induction of IFN-␥.

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Section: Discussionsupporting

confidence: 92%

Experimental Infection of Neonatal Foals withRhodococcus equiTriggers Adult-Like Gamma Interferon Induction

Jacks

Giguère

Crawford

et al. 2007

Clin Vaccine Immunol

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“…Although the proportion of B lymphocytes in the peripheral blood of foals (20 to 30%) is significantly greater than that of adult horses (5 to 10%) (7), the resulting small difference in the proportion of T lymphocytes between foals and adults is unlikely to be responsible for the profound difference in antigenspecific lymphocyte proliferation observed in the present study. Limited antigen-specific lymphoproliferative responses in foals are unlikely to be a result of an impaired proliferative ability of neonatal lymphocytes because previous studies have indicated that foals and adult horses have similar lymphoproliferative responses in response to stimulation with concanavalin A (6,11). In the present study, lymphoproliferative responses to pokeweed mitogen were significantly higher in adult horses than in both groups of foals.…”

Section: Vol 17 2010 Responses To Vaccination In Foals 1899supporting

confidence: 42%

“…Recent work supports these findings, showing that active B-cell development and immunoglobulin isotype switching occur during equine gestation and the neonatal period (27). Proliferation of peripheral blood lymphocytes in response to mitogens is slightly reduced at birth but rapidly increases to adult levels (6,25). Foals also have normal lymphokine-activated killing (LAK) cell activity of peripheral blood lymphocytes at birth and during early life (6).…”

mentioning

confidence: 81%

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Equine Neonates Have Attenuated Humoral and Cell-Mediated Immune Responses to a Killed Adjuvanted Vaccine Compared to Adult Horses

Ryan

Giguère

2010

Clin Vaccine Immunol

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The objectives of this study were to compare relative vaccine-specific serum immunoglobulin concentrations, vaccine-specific lymphoproliferative responses, and cytokine profiles of proliferating lymphocytes between 3-day-old foals, 3-month-old foals, and adult horses after vaccination with a killed adjuvanted vaccine. Horses were vaccinated intramuscularly twice at 3-week intervals with a vaccine containing antigens from bovine viral respiratory pathogens to avoid interference from maternal antibody. Both groups of foals and adult horses responded to the vaccine with a significant increase in vaccine-specific IgGa and IgG(T) concentrations. In contrast, only adult horses and 3-month-old foals mounted significant vaccine-specific total IgG, IgGb, and IgM responses. Vaccine-specific concentrations of IgM and IgG(T) were significantly different between all groups, with the highest concentrations occurring in adult horses, followed by 3-month-old foals and, finally, 3-day-old foals. Only the adult horses mounted significant vaccine-specific lymphoproliferative responses. Baseline gamma interferon (IFN-␥) and interleukin-4 (IL-4) concentrations

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“…Peripheral blood was collected via jugular venipuncture into Vacutainer tubes containing heparin, EDTA, or no additives for lymphocyte phenotyping, hemogram assessment, or serum immunoglobulin concentration determination, respectively. Peripheral blood lymphocytes were isolated from heparinized venous samples using methods described previously (19). The isolated cells were processed for immunophenotyping using flow cytometry, and the excess were snap-frozen for gene expression analyses.…”

Section: Methodsmentioning

confidence: 99%

Fell Pony Syndrome: Characterization of Developmental Hematopoiesis Failure and Associated Gene Expression Profiles

Tallmadge

Stokol

Gould-Earley

et al. 2012

Clin. Vaccine Immunol.

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c Fell Pony syndrome (FPS) is a fatal immunodeficiency that occurs in foals of the Fell Pony breed. Affected foals present with severe anemia, B cell lymphopenia, and opportunistic infections. Our objective was to conduct a prospective study of potential FPS-affected Fell Pony foals to establish clinical, immunological, and molecular parameters at birth and in the first few weeks of life. Complete blood counts, peripheral blood lymphocyte phenotyping, and serum immunoglobulin concentrations were determined for 3 FPS-affected foals, 49 unaffected foals, and 6 adult horses. In addition, cytology of bone marrow aspirates was performed sequentially in a subset of foals. At birth, the FPS-affected foals were not noticeably ill and had hematocrit and circulating B cell counts comparable to those of unaffected foals; however, over 6 weeks, values for both parameters steadily declined. A bone marrow aspirate from a 3-week-old FPS-affected foal revealed erythroid hyperplasia and concurrent erythroid and myeloid dysplasia, which progressed to a severe erythroid hypoplasia at 5 weeks of life. Immunohistochemical staining confirmed the paucity of B cells in primary and secondary lymphoid tissues. The mRNA expression of genes involved in B cell development, signaling, and maturation was investigated using qualitative and quantitative reverse transcriptase PCR (RT-PCR). Several genes, including CREB1, EP300, MYB, PAX5, and SPI1/PU.1, were sequenced from FPS-affected and unaffected foals. Our study presents evidence of fetal erythrocyte and B cell hematopoiesis with rapid postnatal development of anemia and B lymphopenia in FPS-affected foals. The transition between fetal/neonatal and adult-like hematopoiesis may be an important aspect of the pathogenesis of FPS.

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Characterization of peripheral blood and pulmonary leukocyte function in healthy foals

Cited by 74 publications

References 30 publications

Experimental Infection of Neonatal Foals withRhodococcus equiTriggers Adult-Like Gamma Interferon Induction

Experimental Infection of Neonatal Foals withRhodococcus equiTriggers Adult-Like Gamma Interferon Induction

Equine Neonates Have Attenuated Humoral and Cell-Mediated Immune Responses to a Killed Adjuvanted Vaccine Compared to Adult Horses

Fell Pony Syndrome: Characterization of Developmental Hematopoiesis Failure and Associated Gene Expression Profiles

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