Erythrophagocytosis in the Caprine Hemal Node

Haemal nodes are lymphoid organs found in various mammals and some birds. The structure of haemal nodes has been described in a number of species but not yet in the camel. Therefore, haemal nodes from 10 camels were studied histologically and tested for CD3, CD22, major histocompatibility complex (MHC) class II/DR, alpha-smooth muscle actin and for the demonstration of acid and alkaline phosphatases. The haemal nodes were of spherical or kidney shape with one or two hili and had a capsule and trabeculae of connective tissue and smooth muscles. The main parenchyma was composed of a cortex and a medulla. The cortex was formed from lymphoid follicles and diffuse interfollicular lymphocytes. The medulla consisted of lymphoid cords separated by medullary sinuses. The interfollicular lymphocytes and those in the medullary cord were CD3-positive. The lymphoid follicles showed CD22-positive cells. MHC class II/DR was expressed by most cells of the parenchyma. There were also subcapsular, peritrabecular and medullary blood sinuses. Afferent and efferent lymphatics and lymphatic sinuses were also found. Acid phosphatase-positive cells were localized mainly in the marginal, the interfollicular zone and in the medullary cord. Alkaline phosphatase positivity was observed in the endothelium of the sinuses and in the lymphoid follicles. The morphology of these organs in the camel allows a classification as haemolymph nodes and suggests involvement in blood and lymph filtration.

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“…A few cells were localized in the lymph follicles. This confirms the findings of Ezeasor et al. (1989) in caprine haemal nodes.…”

Section: Discussionsupporting

confidence: 91%

“…(1998) and Cerutti and Guerrero (2001) studied the bovine haemal nodes. The haemal nodes of goat were investigated by Meyer (1917), Ezeasor and Singh (1988) and Ezeasor et al. (1989).…”

Section: Introductionmentioning

confidence: 99%

Histological, Histochemical and Immunohistochemical Study of the Haemal Nodes of the Dromedary Camel

Zidan

Pabst

2004

Anat Histol Embryol

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“…Moreover, as both the haemal node and spleen tested qRT-PCR-positive for viral RNA in a number of animals, it is possible that the former may express a higher density of homing receptors for dendritic cells, macrophages, and other antigen presenting cells than the spleen or lymph node. Previous studies have reported the important contribution of the haemal node in the immune processes of domestic ruminants (Ezeasor et al, 1989;Zhang et al, 2012). The present data therefore suggest that together with the spleen and lymph node, the haemal node is likely to be an important site for generation of immune responses as well a potential replication site for the BEFV in cattle.…”

Section: Discussionsupporting

confidence: 62%

A study of viral tissue tropism and cytokine expression in Bovine Ephemeral Fever

Barigye¹

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While the clinical and pathological aspects of Bovine Ephemeral Fever (BEF) have been studied in cattle, major gaps still remain in our understanding of the pathogenesis of the disease. In particular, the cytokine networks that underlie fever and inflammation during acute BEF, and mechanisms that mediate the nascent adaptive immune response have not been empirically defined. In addition, the potential in vivo replication sites of BEFV, and the mechanistic events that underlie the paresis and chronic paralysis in some field BEF cases have also not been defined. The objectives of this research were: (1) to characterise the plasma kinetics of proinflammatory cytokines (IL-1β, IL-6, TNF-α) and IL-10 during natural BEFV infections in cattle; (2) to evaluate the plasma kinetics of IL-2, IFN-γ, IL-6, and IL-10 during the period of innate-immune response transition; and (3) to determine the overall tissue tropism and potential replication sites, along with assessing the likelihood of neurotropism of BEFV in naturally infected cattle. For the cytokine expression studies, experiments were carried out on two different cohorts of animals raised at two farms at different time points. Briefly, plasma from three BEFV-infected and three uninfected cattle was tested by cytokine-specific cELISA, viraemia monitored by qRT-PCR, and virus neutralising antibody titres determined using a standard protocol. Similarly, plasma from another four virus-infected and uninfected negative control animals was tested for the four study cytokines (IL-2, IFN-γ, IL-6, and IL-10), and viraemia and virus neutralising antibody titres determined. Biological specimens from nine adult cattle that died or were euthanised at different time points following natural BEFV infections were tested for viral antigen and RNA by IHC and qRT-PCR, respectively. In addition, virus isolation in autogenously derived splenic and haemal node cultures, and electron microscopic examination of ultrathin ii sections from various tissues taken from the steer necropsied seven days after BEF diagnosis were performed. For the neurotropism studies, fresh brain, spinal cord, peripheral nerve, and other tissues were collected from four paralysed and six asymptomatic but virus-infected cattle and tested for viral RNA by qRT-PCR.Formalin-fixed tissues were routinely evaluated for histomorphological lesions and for viral antigen presence and distribution by IHC. Unlike the negative controls, plasma concentrations of IL-1β, TNF-α, IL-6, and IL-10 were consistently increased in the three virus-infected animals. Two of these heifers were recumbent and pyrexic on the first day of monitoring and increased cytokine production was already in progress by the time viraemia was detected in all the three infected animals. In all the virus-infected heifers, IL-1β was the most strongly expressed cytokine, IL-6 and IL-10 manifested intermediate plasma concentrations while TNF-α was the least expressed and demonstrated bi-phasic peaks three and five days after the onset of pyrexia. In two of the BEFV-...

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“…Winqvist (1954), Ceccarelli et al (1986), Cerutti et al (1998), and Cerutti and Guerrero (2001) have studied bovine hemal nodes. The hemal nodes of goats have been documented by Singh (1988, 1990) and Ezeasor et al (1989). Recently, Zidan and Pabst (2004) have described the hemolymph node of the dromedary camel.…”

Section: Introductionmentioning

confidence: 93%

Histology of hemal nodes of the water buffalo (Bos bubalus)

Zidan

Pabst

2010

Cell Tissue Res

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Hemal nodes are independent lymphoid organs found in various mammals but are ignored by most immunologists. They seem to play a role in defense against blood-borne infections in some species. The structure of the hemal node has been described in various species but, so far, not in the water buffalo. Specimens were obtained from ten clinically healthy male animals (five calves: 2-3 months old; five bulls: 2-8 years old). Six hemal nodes were obtained from each animal from the mesenteric and perirectal region. The samples were studied by light and transmission electron microscopy. The hemal nodes are bean-shaped or spherical, with one hilus through which the hilus arteries and nerves enter the node and from which veins and lymphatics leave it. The buffalo hemal node has a thin capsule of connective tissue and a few smooth muscle cells. Trabeculae extend from the capsule partially dividing the parenchyma. Subcapsular and trabecular blood sinuses are present. The parenchyma is composed of irregular lymphoid cords rich in erythrocytes, macrophages, and plasma cells and is separated by blood sinuses of variable size engorged with blood. These blood sinuses drain into the trabecular sinuses and then into the subcapsular sinus. In calves, the size of the lymphoid cords is larger than that in adult bulls. Buffalo hemal nodes can be classified as typical hemal nodes, because they are definitely different from hemolymph nodes in other species. They may play a role in filtering the blood.

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Erythrophagocytosis in the Caprine Hemal Node

Cited by 14 publications

References 5 publications

Histological, Histochemical and Immunohistochemical Study of the Haemal Nodes of the Dromedary Camel

Histological, Histochemical and Immunohistochemical Study of the Haemal Nodes of the Dromedary Camel

A study of viral tissue tropism and cytokine expression in Bovine Ephemeral Fever

Histology of hemal nodes of the water buffalo (Bos bubalus)

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