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Cross reactive cellular immune responses in chickens previously exposed to low pathogenic avian influenza.

Kapczynski DR, Liljebjelke K, Kulkarni G, Hunt H, Jiang HJ, Petkov D - BMC Proc (2011)

Bottom Line: Cellular immunity was determined by cytotoxic lysis of B2/B2 infected lung target cells and proliferation of T cells following exposure to LPAI.Infection with H9N2 resulted in statistically significant weight loss compared to sham-infected birds.T cell proliferation was determined to be highest when exposed to the homologous virus.

View Article: PubMed Central - HTML - PubMed

Affiliation: Southeast Poultry Research Laboratory, Agricultural Research Service, USA, Department of Agriculture, 934 College Station Road, Athens, GA 30605, USA. darrell.kapczynski@ars.usda.gov.

ABSTRACT

Background: Avian influenza (AI) infection in poultry can result in high morbidity and mortality, and negatively affect international trade. Because most AI vaccines used for poultry are inactivated, our knowledge of immunity against AI is based largely on humoral immune responses. In fact, little is known about cellular immunity following a primary AI infection in poultry, especially regarding cytotoxic T lymphocytes (CTL's).

Methods: In these studies, major histocompatibility complex (MHC)-defined (B2/B2) chickens were infected with low pathogenic AI (LPAI) H9N2 and clinical signs of disease were monitored over a two weeks period. Splenic lymphocytes from infected and naïve birds were examined for cross reactivity against homologous and heterologous (H7N2) LPAI by ex vivo stimulation. Cellular immunity was determined by cytotoxic lysis of B2/B2 infected lung target cells and proliferation of T cells following exposure to LPAI.

Results: Infection with H9N2 resulted in statistically significant weight loss compared to sham-infected birds. Splenic lymphocytes derived from H9N2-infected birds displayed lysis of both homologous (H9N2) and heterologous (H7N2) infected target cells, whereas lymphocytes obtained from sham-infected birds did not. T cell proliferation was determined to be highest when exposed to the homologous virus.

Conclusions: Taken together these data extend the findings that cellular immunity, including CTL's, is cross reactive against heterologous isolates of AI and contribute to protection following infection.

No MeSH data available.


Related in: MedlinePlus

Effect of A/chicken/NJ/97 (H9N2) infection on weight gain in MHC-defined (B2/B2) chickens at 2, 4 and 7 days post infection. Two-week old birds received either PBS (Sham) or 107 EID50 H9N2 per bird via intranasal route. Bird weight was significantly reduced between the two groups on each day tested (p<0.05).
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Figure 1: Effect of A/chicken/NJ/97 (H9N2) infection on weight gain in MHC-defined (B2/B2) chickens at 2, 4 and 7 days post infection. Two-week old birds received either PBS (Sham) or 107 EID50 H9N2 per bird via intranasal route. Bird weight was significantly reduced between the two groups on each day tested (p<0.05).

Mentions: Infection with A\Chicken\NJ\97 (H9N2) following a natural route of exposure (intranasal) significantly decreased weight gains at day 2, 4 and 7 post-inoculation compared to control (uninfected) chickens (Fig 1). In general, H9N2 infected birds weighed approximately 10% less than the sham inoculated group at each time point. Apart from weight loss, overt signs of clinical disease or respiratory distress were not observed in the H9N2 challenged group throughout the course of the study.


Cross reactive cellular immune responses in chickens previously exposed to low pathogenic avian influenza.

Kapczynski DR, Liljebjelke K, Kulkarni G, Hunt H, Jiang HJ, Petkov D - BMC Proc (2011)

Effect of A/chicken/NJ/97 (H9N2) infection on weight gain in MHC-defined (B2/B2) chickens at 2, 4 and 7 days post infection. Two-week old birds received either PBS (Sham) or 107 EID50 H9N2 per bird via intranasal route. Bird weight was significantly reduced between the two groups on each day tested (p<0.05).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3108207&req=5

Figure 1: Effect of A/chicken/NJ/97 (H9N2) infection on weight gain in MHC-defined (B2/B2) chickens at 2, 4 and 7 days post infection. Two-week old birds received either PBS (Sham) or 107 EID50 H9N2 per bird via intranasal route. Bird weight was significantly reduced between the two groups on each day tested (p<0.05).
Mentions: Infection with A\Chicken\NJ\97 (H9N2) following a natural route of exposure (intranasal) significantly decreased weight gains at day 2, 4 and 7 post-inoculation compared to control (uninfected) chickens (Fig 1). In general, H9N2 infected birds weighed approximately 10% less than the sham inoculated group at each time point. Apart from weight loss, overt signs of clinical disease or respiratory distress were not observed in the H9N2 challenged group throughout the course of the study.

Bottom Line: Cellular immunity was determined by cytotoxic lysis of B2/B2 infected lung target cells and proliferation of T cells following exposure to LPAI.Infection with H9N2 resulted in statistically significant weight loss compared to sham-infected birds.T cell proliferation was determined to be highest when exposed to the homologous virus.

View Article: PubMed Central - HTML - PubMed

Affiliation: Southeast Poultry Research Laboratory, Agricultural Research Service, USA, Department of Agriculture, 934 College Station Road, Athens, GA 30605, USA. darrell.kapczynski@ars.usda.gov.

ABSTRACT

Background: Avian influenza (AI) infection in poultry can result in high morbidity and mortality, and negatively affect international trade. Because most AI vaccines used for poultry are inactivated, our knowledge of immunity against AI is based largely on humoral immune responses. In fact, little is known about cellular immunity following a primary AI infection in poultry, especially regarding cytotoxic T lymphocytes (CTL's).

Methods: In these studies, major histocompatibility complex (MHC)-defined (B2/B2) chickens were infected with low pathogenic AI (LPAI) H9N2 and clinical signs of disease were monitored over a two weeks period. Splenic lymphocytes from infected and naïve birds were examined for cross reactivity against homologous and heterologous (H7N2) LPAI by ex vivo stimulation. Cellular immunity was determined by cytotoxic lysis of B2/B2 infected lung target cells and proliferation of T cells following exposure to LPAI.

Results: Infection with H9N2 resulted in statistically significant weight loss compared to sham-infected birds. Splenic lymphocytes derived from H9N2-infected birds displayed lysis of both homologous (H9N2) and heterologous (H7N2) infected target cells, whereas lymphocytes obtained from sham-infected birds did not. T cell proliferation was determined to be highest when exposed to the homologous virus.

Conclusions: Taken together these data extend the findings that cellular immunity, including CTL's, is cross reactive against heterologous isolates of AI and contribute to protection following infection.

No MeSH data available.


Related in: MedlinePlus