Distinct Mechanisms Underlie Boosted Polysaccharide-Specific IgG Responses Following Secondary Challenge with Intact Gram-Negative versus Gram-Positive Extracellular Bacteria.
Swagata KarSwadhinya ArjunarajaMustafa AkkoyunluGerald B PierClifford M SnapperPublished in: Journal of immunology (Baltimore, Md. : 1950) (2016)
Priming of mice with intact, heat-killed cells of Gram-negative Neisseria meningitidis, capsular serogroup C (MenC) or Gram-positive group B Streptococcus, capsular type III (GBS-III) bacteria resulted in augmented serum polysaccharide (PS)-specific IgG titers following booster immunization. Induction of memory required CD4(+) T cells during primary immunization. We determined whether PS-specific memory for IgG production was contained within the B cell and/or T cell populations, and whether augmented IgG responses following booster immunization were also dependent on CD4(+) T cells. Adoptive transfer of purified B cells from MenC- or GBS-III-primed, but not naive mice resulted in augmented PS-specific IgG responses following booster immunization. Similar responses were observed when cotransferred CD4(+) T cells were from primed or naive mice. Similarly, primary immunization with unencapsulated MenC or GBS-III, to potentially prime CD4(+) T cells, failed to enhance PS-specific IgG responses following booster immunization with their encapsulated isogenic partners. Furthermore, in contrast to GBS-III, depletion of CD4(+) T cells during secondary immunization with MenC or another Gram-negative bacteria, Acinetobacter baumannii, did not inhibit augmented PS-specific IgG booster responses of mice primed with heat-killed cells. Also, in contrast with GBS-III, booster immunization of MenC-primed mice with isolated MenC-PS, a TI Ag, or a conjugate of MenC-PS and tetanus toxoid elicited an augmented PS-specific IgG response similar to booster immunization with intact MenC. These data demonstrate that memory for augmented PS-specific IgG booster responses to Gram-negative and Gram-positive bacteria is contained solely within the B cell compartment, with a differential requirement for CD4(+) T cells for augmented IgG responses following booster immunization.
Keyphrases
- gram negative
- multidrug resistant
- acinetobacter baumannii
- drug resistant
- induced apoptosis
- high fat diet induced
- magnetic resonance
- pseudomonas aeruginosa
- virtual reality
- type diabetes
- insulin resistance
- cystic fibrosis
- cell death
- metabolic syndrome
- drug delivery
- wild type
- quantum dots
- signaling pathway
- big data
- adipose tissue
- skeletal muscle
- cell cycle arrest
- highly efficient
- pi k akt