Maintenance of high virus load even after seroconversion in newborn cats acutely infected with feline immunodeficiency virus

Vaccine ◽  
1995 ◽  
Vol 13 (15) ◽  
pp. 1393-1398 ◽  
Author(s):  
Kenzo Tokunaga ◽  
Koichi Shoda ◽  
Yoshii Nishino ◽  
Shiro Mori ◽  
Qiu Zhong ◽  
...  
Keyword(s):  
Feline Immunodeficiency Virus ◽  
Virus Load ◽  
Immunodeficiency Virus ◽  
High Virus

scholarly journals Lentivirus-Specific Cytotoxic T-Lymphocyte Responses Are Rapidly Lost in Thymectomized Cats Infected with Feline Immunodeficiency Virus

2005 ◽  
Vol 79 (13) ◽  
pp. 8237-8242 ◽  
Author(s):  
Kathleen A. Hayes ◽  
Sadi Köksoy ◽  
Andrew J. Phipps ◽  
Wayne R. Buck ◽  
Gary J. Kociba ◽  
...  
Keyword(s):  
T Lymphocyte ◽  
Feline Immunodeficiency Virus ◽  
Cytotoxic T Lymphocyte ◽  
Significant Loss ◽  
Ctl Response ◽  
Virus Load ◽  
Immunodeficiency Virus ◽  
Plasma Virus Load ◽  
Lymphocyte Responses ◽  
Ctl Responses

ABSTRACT To what extent the thymus is needed to preserve the virus-specific cytotoxic T-lymphocyte (CTL) response of lentivirus-infected adults is unclear. Presented here is the first definitive study using thymectomized (ThX) animals to directly evaluate the contribution of thymic function to lentivirus-specific CTL response and the control of lentivirus infections. ThX and mock-ThX cats were inoculated with feline immunodeficiency virus (FIV) and monitored for their FIV-specific CTL responses. Early in infection, both FIV-ThX and FIV-mock-ThX cats produced similar CTL responses, but surprisingly, after 20 weeks, the FIV-ThX cats showed a statistically significant loss of FIV-specific CTL activity, while FIV-infected cats with intact thymuses continued to maintain FIV-specific CTL. The loss of CTL did not affect plasma virus load, which remained elevated for both groups. These results emphasize the importance of thymic integrity in maintaining immunity to lentiviruses, but also bring into question the notion that virus load is regulated predominantly by the virus-specific CTL response.

scholarly journals Persistence of High Virus Neutralizing Antibody Titers in Cats Experimentally Infected with Feline Immunodeficiency Virus.

1996 ◽  
Vol 58 (9) ◽  
pp. 925-927 ◽  
Author(s):  
Yasuo INOSHIMA ◽  
Yasuhiro IKEDA ◽  
Mariko KOHMOTO ◽  
Marcelo Ricardo PECORARO ◽  
Masayuki SHIMOJIMA ◽  
...  
Keyword(s):  
Feline Immunodeficiency Virus ◽  
Neutralizing Antibody ◽  
Immunodeficiency Virus ◽  
Antibody Titers ◽  
High Virus

scholarly journals Effect of a Protease Inhibitor-Induced Genetic Bottleneck on Human Immunodeficiency Virus Type 1 env Gene Populations

2005 ◽  
Vol 79 (16) ◽  
pp. 10627-10637 ◽  
Author(s):  
Kathryn M. Kitrinos ◽  
Julie A. E. Nelson ◽  
Wolfgang Resch ◽  
Ronald Swanstrom
Keyword(s):  
Human Immunodeficiency Virus ◽  
Genetic Bottleneck ◽  
Load Reduction ◽  
Resistance Mutations ◽  
Virus Load ◽  
Immunodeficiency Virus ◽  
Initial Drop ◽  
High Virus ◽  
Hiv 1

ABSTRACT The initiation of drug therapy or the addition of a new drug to preexisting therapy can have a significant impact on human immunodeficiency virus type 1 (HIV-1) populations within a person. Drug therapy directed at reverse transcriptase and protease can result in dramatic decreases in virus load, causing a contraction in the virus population that represents a potential genetic bottleneck as a subset of virus with genomes carrying resistance mutations repopulate the host. While this bottleneck exerts an effect directly on the region that is being targeted by the drugs, it also affects other regions of the viral genome. We have applied heteroduplex tracking assays (HTA) specific to variable regions 1 and 2 (V1/V2) and variable region 3 (V3) of the HIV-1 env gene to analyze the effect of a genetic bottleneck created by the selection of resistance to ritonavir, a protease inhibitor. Subjects were classified into groups on the basis of the extent of the initial drop in virus load and the duration of virus load reduction. Subjects with a strong initial drop in virus load exhibited a loss of heterogeneity in the env region at virus load rebound; in contrast, subjects with a weak initial drop in virus load exhibited little to no loss of heterogeneity at virus load rebound in either region of env examined. The duration of virus load reduction also affected env populations. Subjects that had prolonged reductions exhibited slower population diversification and the appearance of new V1/V2 species after rebound. The longer reduction of virus load in these subjects may have allowed for improved immune system function, which in turn could have selected for new escape mutants. Subjects with rapid rebound quickly reequilibrated the entry env variants back into the resistant population. When the pro gene developed further resistance mutations subsequent to virus load rebound, no changes were observed in V1/V2 or V3 populations, suggesting that the high virus loads allowed the env populations to reequilibrate rapidly. The rapid equilibration of env variants during pro gene sequence transitions at high virus load suggests that recombination is active in defining the HIV-1 sequence population. Conversely, part of the success of suppressive antiviral therapy may be to limit the potential for evolution through recombination, which requires dually infected cells.

Competitive polymerase chain reaction for quantitating feline immunodeficiency virus load in infected cat tissues

1994 ◽  
Vol 8 (3) ◽  
pp. 229-234 ◽  
Author(s):  
Mauro Pistello ◽  
Stefano Menzo ◽  
Massimo Giorgi ◽  
Luigi Da Prato ◽  
Giancarlo Cammarota ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Feline Immunodeficiency Virus ◽  
Chain Reaction ◽  
Competitive Polymerase Chain Reaction ◽  
Virus Load ◽  
Immunodeficiency Virus ◽  
Polymerase Chain

scholarly journals Vaccination with Inactivated Virus but Not Viral DNA Reduces Virus Load following Challenge with a Heterologous and Virulent Isolate of Feline Immunodeficiency Virus

2000 ◽  
Vol 74 (20) ◽  
pp. 9403-9411 ◽  
Author(s):  
Margaret J. Hosie ◽  
Thomas Dunsford ◽  
Dieter Klein ◽  
Brian J. Willett ◽  
Celia Cannon ◽  
...  
Keyword(s):  
Feline Immunodeficiency Virus ◽  
Neutralizing Antibodies ◽  
Vaccine Development ◽  
Complete Protection ◽  
Virus Load ◽  
Virus Particles ◽  
Virulent Isolate ◽  
Load Following ◽  
Immunodeficiency Virus ◽  
Attenuated Isolate

ABSTRACT It has been shown that cats can be protected against infection with the prototypic Petaluma strain of feline immunodeficiency virus (FIVPET) using vaccines based on either inactivated virus particles or replication-defective proviral DNA. However, the utility of such vaccines in the field is uncertain, given the absence of consistent protection against antigenically distinct strains and the concern that the Petaluma strain may be an unrepresentative, attenuated isolate. Since reduction of viral pathogenicity and dissemination may be useful outcomes of vaccination, even in the absence of complete protection, we tested whether either of these vaccine strategies ameliorates the early course of infection following challenge with heterologous and more virulent isolates. We now report that an inactivated virus vaccine, which generates high levels of virus neutralizing antibodies, confers reduced virus loads following challenge with two heterologous isolates, FIVAM6 and FIVGL8. This vaccine also prevented the marked early decline in CD4/CD8 ratio seen in FIVGL8-infected cats. In contrast, DNA vaccines based on either FIVPET or FIVGL8, which induce cell-mediated responses but no detectable antiviral antibodies, protected a fraction of cats against infection with FIVPET but had no measurable effect on virus load when the infecting virus was FIVGL8. These results indicate that the more virulent FIVGL8 is intrinsically more resistant to vaccinal immunity than the FIVPET strain and that a broad spectrum of responses which includes virus neutralizing antibodies is a desirable goal for lentivirus vaccine development.

Serum neutralization of feline immunodeficiency virus is markedly dependent on passage history of the virus and host system.

1994 ◽  
Vol 68 (7) ◽  
pp. 4572-4579 ◽  
Author(s):  
F Baldinotti ◽  
D Matteucci ◽  
P Mazzetti ◽  
C Giannelli ◽  
P Bandecchi ◽  
...  
Keyword(s):  
Feline Immunodeficiency Virus ◽  
Host System ◽  
Serum Neutralization ◽  
Immunodeficiency Virus ◽  
History Of

scholarly journals Occurrence of feline immunodeficiency virus and feline leukaemia virus in Maputo city and province, Mozambique: a pilot study

2019 ◽  
Vol 5 (2) ◽  
pp. 205511691987087
Author(s):  
Cesaltina CLM Tchamo ◽  
Mónica De Rugeriis ◽  
Emília V Noormahomed
Keyword(s):  
Positive Result ◽  
Feline Immunodeficiency Virus ◽  
Urban Areas ◽  
African Countries ◽  
Leukaemia Virus ◽  
Zoonotic Pathogens ◽  
Test Kit ◽  
Immunodeficiency Virus ◽  
Feline Leukaemia Virus ◽  
Veterinary Faculty

Objectives Feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV) are immunosuppressive viruses in cats that increase their susceptibility to zoonotic pathogens. This study aimed to determine the occurrence of one or both viruses, the risk factors associated with infection, and to develop further recommendations. Methods This was a cross-sectional study conducted at the Veterinary Faculty of Eduardo Mondlane University, Mozambique, between March and December 2017, in 145 cats. From each of 145 cats, we took 1.5 ml of blood by jugular puncture for detection of antibodies to FIV and FeLV antigens in whole blood using a commercial test kit, DFV Test FeLV/FIV. Results We found an overall prevalence of 11.0% and 14.5% for FIV antibodies and FeLV antigens, respectively, with four (2.8%) cats coinfected by both pathogens. Male cats were more likely to be infected with FIV (odds ratio [OR] 1.1, 95% confidence interval [CI] 0.3–4.0) compared with female cats. Clinically ill cats were more likely to have a positive result for FeLV antigen infection (OR 18.8, 95% CI 5.2–68.3). Moreover, cats living in suburban areas have a greater chance of a positive result for FeLV infection (OR 3.7, 95% CI 1.4–9.6) compared with cats living in urban areas. Conclusions and relevance FIV and FeLV occur in cats from Maputo and possibly all over the country. Further studies should be conducted in Mozambique and other African countries to define the burden of both pathogens in cats, coinfection with other zoonotic pathogens and the possible role played by the cats on the transmission of zoonotic and opportunistic diseases to humans.

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