Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0017160 (gastroenteritis)
 11,398 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Despite the pioneering efforts to identify correlates of passive immunity to transmissible gastroenteritis virus (TGEV), effective vaccines for the control of TGE in suckling pigs have remained elusive. The initial concept of an enteromammary immunologic axis in monogastrics originated from studies of lactogenic immunity to TGEV in swine. These studies revealed that infection of pregnant swine with virulent TGEV stimulated high titers of SIgA antibodies in milk which correlated with protection of suckling pigs against TGE; parenteral or oral inoculation with live attenuated or killed TGEV vaccines induced mainly IgG antibodies in milk which generally provided poor protection to suckling pigs. The recent appearance of PRCV infections in swine and continuing studies of TGEV infections, present a unique model for further studies of mucosal immunity. Research using these viruses has increased our understanding of the various components of the common mucosal immune system and their interactions. Although the most important consideration in designing an effective vaccine for TGEV is the stimulation of GALT through intestinal virus replication, studies addressing the contribution of BALT to immunity to TGEV and PRCV may provide insights for alternative vaccine approaches. The mechanism by which exposure to PRCV elicits a variable-degree of immunity to TGEV challenge is unknown. Virus replication in the gut or respiratory tract is a major factor affecting the magnitude of the immune response at the respective site and may be necessary for the recruitment of specific immune cells from other mucosal inductive sites, i.e., GALT to BALT and BALT to GALT migration.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Immunity to transmissible gastroenteritis virus and porcine respiratory coronavirus infections in swine. 785 68

Two antigenically related porcine coronaviruses, transmissible gastroenteritis virus (TGEV) which infects primarily the intestinal tract and causes severe diarrhea, and porcine respiratory coronavirus (PRCV) which infects the respiratory tract and causes subclinical or mild respiratory infections, presented a unique opportunity to study the interrelationship of gut-(GALT) and bronchus-associated lymphoid tissues (BALT) and their contribution to protective immunity against TGEV infection. Pigs were inoculated oral-nasally with TGEV or with PRCV at eleven days of age and challenged 24 days later with TGEV. All pigs initially given TGEV developed diarrhea and were completely protected against disease upon challenge. In contrast, pigs given PRCV had no clinical disease and shed virus in nasal secretions only; after challenge, 5 of 12 pigs developed diarrhea. Virus-specific IgG and IgA Ab-secreting cells (ASC) were enumerated by ELISPOT in the mesenteric and bronchial lymph nodes, spleens, and gut lamina propria at challenge and various post challenge days. Before challenge, in pigs exposed to TGEV, IgA-ASC in the duodenum and jejunum constituted the major ASC response. Conversely, PRCV-exposed pigs had mainly IgG-ASC in bronchial lymph nodes, with low ASC responses in the gut. After challenge, numbers of IgG-ASC increased rapidly in the gut lamina propria and mesenteric lymph nodes of only PRCV-primed pigs. Our results suggest that virus-specific IgG-ASC precursors derived in BALT of PRCV-primed pigs may migrate to the gut in response to TGEV challenge and contribute to the partial protection observed. The presence of IgA-ASC in the gut lamina propria of TGEV-primed pigs at the time of challenge correlated with complete protection against TGEV challenge. Thus a dichotomy exists in the BALT and GALT ASC responses; immunization via BALT induced a systemic type of response (IgG-ASC) and provided imperfect protection against an enteric pathogen, whereas immunization via GALT induced IgA-ASC and provided complete protection.
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PMID:Contribution of antibody-secreting cells induced in mucosal lymphoid tissues of pigs inoculated with respiratory or enteric strains of coronavirus to immunity against enteric coronavirus challenge. 814 65

Based on the tenet of a common mucosal immune system, antigenic stimulation at one mucosal site results in the distribution of antigen-specific IgA precursor cells to distant mucosal sites. However, recent studies suggest that functional compartmentalization and limited reciprocity may exist within some components of the common mucosal immune system. Although oral immunization is often very effective in inducing immunity to respiratory pathogens, the converse (respiratory immunization to prevent enteric diseases) may not be as effective. To address this question and to study interactions between the bronchus-associated (BALT) and gut-associated (GALT) lymphoid tissues related to protective immunity, we used as a model two antigenically related porcine coronaviruses which replicate primarily in the intestine (transmissible gastroenteritis virus, TGEV) or respiratory tract (porcine respiratory coronavirus, PRCV). The tissue distribution and magnitude of the antibody secreting cell (ASC) responses (measured by ELISPOT) and cell-mediated immune responses (measured by lymphoproliferative assays, LPA) coincided with the viral tissue tropisms. Immunization via GALT (gut infection with TGEV) elicited high numbers of IgA ASC and high LPA responses in GALT (gut lamina propria, LP or mesenteric lymph nodes, MLN), but lower responses in BALT (bronchial lymph nodes, BLN) and induced complete protection against enteric TGEV challenge. In contrast immunization via BALT (respiratory infection with PRCV) elicited systemic type responses (high numbers of IgG ASC in the BLN), but few ASC and low LPA responses in the gut LP or MLN and induced only partial protection against enteric TGEV challenge. Thus administration of vaccines intranasally may not be optimally effective for inducing intestinal immunity in contrast to the reported efficacy of oral vaccines for inducing respiratory immunity.
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PMID:Mucosal immunity: an overview and studies of enteric and respiratory coronavirus infections in a swine model of enteric disease. 898 61

Infantile acute gastroenteritis is still a frequent problem particularly in younger children, with high mortality rate in developing countries and high impact on health costs in industrialized countries. The increased knowledge on its pathophysiology has led to the definition of two distinct mechanisms of diarrhea: the secretory and the osmotic pathway. Investigation on the host-microorganism interaction revealed a complex scenario with sophisticated mechanisms developed by microorganisms during evolution to overcome the host defense system. The latter includes immune and non immune coordinated components, with a major role played by the GALT (gut associated lymphoreticular tissue). Knowledge of epidemiology and of the natural history of intestinal infections has led to rational diagnostic approach with substantial cut of medical costs. Novel therapeutic strategies have been made available with the use of probiotics and of passive immunotherapy together with a dramatic reduction of antibiotic treatment. HIV pandemy raises major problems which need rapid responses.
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PMID:[Acute infectious diarrhea in children]. 1023 81